chiark / gitweb /
delta: diff returns 1 when files differ, ignore this
[elogind.git] / src / nspawn / nspawn.c
1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
2
3 /***
4   This file is part of systemd.
5
6   Copyright 2010 Lennart Poettering
7
8   systemd is free software; you can redistribute it and/or modify it
9   under the terms of the GNU Lesser General Public License as published by
10   the Free Software Foundation; either version 2.1 of the License, or
11   (at your option) any later version.
12
13   systemd is distributed in the hope that it will be useful, but
14   WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16   Lesser General Public License for more details.
17
18   You should have received a copy of the GNU Lesser General Public License
19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 ***/
21
22 #include <signal.h>
23 #include <sched.h>
24 #include <unistd.h>
25 #include <sys/types.h>
26 #include <sys/syscall.h>
27 #include <sys/mount.h>
28 #include <sys/wait.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <stdio.h>
32 #include <errno.h>
33 #include <sys/prctl.h>
34 #include <sys/capability.h>
35 #include <getopt.h>
36 #include <termios.h>
37 #include <sys/signalfd.h>
38 #include <grp.h>
39 #include <linux/fs.h>
40 #include <sys/un.h>
41 #include <sys/socket.h>
42 #include <linux/netlink.h>
43 #include <net/if.h>
44 #include <linux/veth.h>
45 #include <sys/personality.h>
46 #include <linux/loop.h>
47
48 #ifdef HAVE_SELINUX
49 #include <selinux/selinux.h>
50 #endif
51
52 #ifdef HAVE_SECCOMP
53 #include <seccomp.h>
54 #endif
55
56 #ifdef HAVE_BLKID
57 #include <blkid/blkid.h>
58 #endif
59
60 #include "sd-daemon.h"
61 #include "sd-bus.h"
62 #include "sd-id128.h"
63 #include "sd-rtnl.h"
64 #include "log.h"
65 #include "util.h"
66 #include "mkdir.h"
67 #include "macro.h"
68 #include "audit.h"
69 #include "missing.h"
70 #include "cgroup-util.h"
71 #include "strv.h"
72 #include "path-util.h"
73 #include "loopback-setup.h"
74 #include "dev-setup.h"
75 #include "fdset.h"
76 #include "build.h"
77 #include "fileio.h"
78 #include "bus-util.h"
79 #include "bus-error.h"
80 #include "ptyfwd.h"
81 #include "bus-kernel.h"
82 #include "env-util.h"
83 #include "def.h"
84 #include "rtnl-util.h"
85 #include "udev-util.h"
86 #include "blkid-util.h"
87 #include "gpt.h"
88 #include "siphash24.h"
89 #include "copy.h"
90 #include "base-filesystem.h"
91 #include "barrier.h"
92 #include "event-util.h"
93
94 #ifdef HAVE_SECCOMP
95 #include "seccomp-util.h"
96 #endif
97
98 typedef enum ContainerStatus {
99         CONTAINER_TERMINATED,
100         CONTAINER_REBOOTED
101 } ContainerStatus;
102
103 typedef enum LinkJournal {
104         LINK_NO,
105         LINK_AUTO,
106         LINK_HOST,
107         LINK_GUEST
108 } LinkJournal;
109
110 typedef enum Volatile {
111         VOLATILE_NO,
112         VOLATILE_YES,
113         VOLATILE_STATE,
114 } Volatile;
115
116 static char *arg_directory = NULL;
117 static char *arg_user = NULL;
118 static sd_id128_t arg_uuid = {};
119 static char *arg_machine = NULL;
120 static const char *arg_selinux_context = NULL;
121 static const char *arg_selinux_apifs_context = NULL;
122 static const char *arg_slice = NULL;
123 static bool arg_private_network = false;
124 static bool arg_read_only = false;
125 static bool arg_boot = false;
126 static LinkJournal arg_link_journal = LINK_AUTO;
127 static bool arg_link_journal_try = false;
128 static uint64_t arg_retain =
129         (1ULL << CAP_CHOWN) |
130         (1ULL << CAP_DAC_OVERRIDE) |
131         (1ULL << CAP_DAC_READ_SEARCH) |
132         (1ULL << CAP_FOWNER) |
133         (1ULL << CAP_FSETID) |
134         (1ULL << CAP_IPC_OWNER) |
135         (1ULL << CAP_KILL) |
136         (1ULL << CAP_LEASE) |
137         (1ULL << CAP_LINUX_IMMUTABLE) |
138         (1ULL << CAP_NET_BIND_SERVICE) |
139         (1ULL << CAP_NET_BROADCAST) |
140         (1ULL << CAP_NET_RAW) |
141         (1ULL << CAP_SETGID) |
142         (1ULL << CAP_SETFCAP) |
143         (1ULL << CAP_SETPCAP) |
144         (1ULL << CAP_SETUID) |
145         (1ULL << CAP_SYS_ADMIN) |
146         (1ULL << CAP_SYS_CHROOT) |
147         (1ULL << CAP_SYS_NICE) |
148         (1ULL << CAP_SYS_PTRACE) |
149         (1ULL << CAP_SYS_TTY_CONFIG) |
150         (1ULL << CAP_SYS_RESOURCE) |
151         (1ULL << CAP_SYS_BOOT) |
152         (1ULL << CAP_AUDIT_WRITE) |
153         (1ULL << CAP_AUDIT_CONTROL) |
154         (1ULL << CAP_MKNOD);
155 static char **arg_bind = NULL;
156 static char **arg_bind_ro = NULL;
157 static char **arg_tmpfs = NULL;
158 static char **arg_setenv = NULL;
159 static bool arg_quiet = false;
160 static bool arg_share_system = false;
161 static bool arg_register = true;
162 static bool arg_keep_unit = false;
163 static char **arg_network_interfaces = NULL;
164 static char **arg_network_macvlan = NULL;
165 static bool arg_network_veth = false;
166 static const char *arg_network_bridge = NULL;
167 static unsigned long arg_personality = 0xffffffffLU;
168 static const char *arg_image = NULL;
169 static Volatile arg_volatile = VOLATILE_NO;
170
171 static void help(void) {
172         printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
173                "Spawn a minimal namespace container for debugging, testing and building.\n\n"
174                "  -h --help                 Show this help\n"
175                "     --version              Print version string\n"
176                "  -q --quiet                Do not show status information\n"
177                "  -D --directory=PATH       Root directory for the container\n"
178                "  -i --image=PATH           File system device or image for the container\n"
179                "  -b --boot                 Boot up full system (i.e. invoke init)\n"
180                "  -u --user=USER            Run the command under specified user or uid\n"
181                "  -M --machine=NAME         Set the machine name for the container\n"
182                "     --uuid=UUID            Set a specific machine UUID for the container\n"
183                "  -S --slice=SLICE          Place the container in the specified slice\n"
184                "     --private-network      Disable network in container\n"
185                "     --network-interface=INTERFACE\n"
186                "                            Assign an existing network interface to the\n"
187                "                            container\n"
188                "     --network-macvlan=INTERFACE\n"
189                "                            Create a macvlan network interface based on an\n"
190                "                            existing network interface to the container\n"
191                "     --network-veth         Add a virtual ethernet connection between host\n"
192                "                            and container\n"
193                "     --network-bridge=INTERFACE\n"
194                "                            Add a virtual ethernet connection between host\n"
195                "                            and container and add it to an existing bridge on\n"
196                "                            the host\n"
197                "  -Z --selinux-context=SECLABEL\n"
198                "                            Set the SELinux security context to be used by\n"
199                "                            processes in the container\n"
200                "  -L --selinux-apifs-context=SECLABEL\n"
201                "                            Set the SELinux security context to be used by\n"
202                "                            API/tmpfs file systems in the container\n"
203                "     --capability=CAP       In addition to the default, retain specified\n"
204                "                            capability\n"
205                "     --drop-capability=CAP  Drop the specified capability from the default set\n"
206                "     --link-journal=MODE    Link up guest journal, one of no, auto, guest, host,\n"
207                "                            try-guest, try-host\n"
208                "  -j                        Equivalent to --link-journal=try-guest\n"
209                "     --read-only            Mount the root directory read-only\n"
210                "     --bind=PATH[:PATH]     Bind mount a file or directory from the host into\n"
211                "                            the container\n"
212                "     --bind-ro=PATH[:PATH]  Similar, but creates a read-only bind mount\n"
213                "     --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n"
214                "     --setenv=NAME=VALUE    Pass an environment variable to PID 1\n"
215                "     --share-system         Share system namespaces with host\n"
216                "     --register=BOOLEAN     Register container as machine\n"
217                "     --keep-unit            Do not register a scope for the machine, reuse\n"
218                "                            the service unit nspawn is running in\n"
219                "     --volatile[=MODE]      Run the system in volatile mode\n",
220                program_invocation_short_name);
221 }
222
223 static int parse_argv(int argc, char *argv[]) {
224
225         enum {
226                 ARG_VERSION = 0x100,
227                 ARG_PRIVATE_NETWORK,
228                 ARG_UUID,
229                 ARG_READ_ONLY,
230                 ARG_CAPABILITY,
231                 ARG_DROP_CAPABILITY,
232                 ARG_LINK_JOURNAL,
233                 ARG_BIND,
234                 ARG_BIND_RO,
235                 ARG_TMPFS,
236                 ARG_SETENV,
237                 ARG_SHARE_SYSTEM,
238                 ARG_REGISTER,
239                 ARG_KEEP_UNIT,
240                 ARG_NETWORK_INTERFACE,
241                 ARG_NETWORK_MACVLAN,
242                 ARG_NETWORK_VETH,
243                 ARG_NETWORK_BRIDGE,
244                 ARG_PERSONALITY,
245                 ARG_VOLATILE,
246         };
247
248         static const struct option options[] = {
249                 { "help",                  no_argument,       NULL, 'h'                   },
250                 { "version",               no_argument,       NULL, ARG_VERSION           },
251                 { "directory",             required_argument, NULL, 'D'                   },
252                 { "user",                  required_argument, NULL, 'u'                   },
253                 { "private-network",       no_argument,       NULL, ARG_PRIVATE_NETWORK   },
254                 { "boot",                  no_argument,       NULL, 'b'                   },
255                 { "uuid",                  required_argument, NULL, ARG_UUID              },
256                 { "read-only",             no_argument,       NULL, ARG_READ_ONLY         },
257                 { "capability",            required_argument, NULL, ARG_CAPABILITY        },
258                 { "drop-capability",       required_argument, NULL, ARG_DROP_CAPABILITY   },
259                 { "link-journal",          required_argument, NULL, ARG_LINK_JOURNAL      },
260                 { "bind",                  required_argument, NULL, ARG_BIND              },
261                 { "bind-ro",               required_argument, NULL, ARG_BIND_RO           },
262                 { "tmpfs",                 required_argument, NULL, ARG_TMPFS             },
263                 { "machine",               required_argument, NULL, 'M'                   },
264                 { "slice",                 required_argument, NULL, 'S'                   },
265                 { "setenv",                required_argument, NULL, ARG_SETENV            },
266                 { "selinux-context",       required_argument, NULL, 'Z'                   },
267                 { "selinux-apifs-context", required_argument, NULL, 'L'                   },
268                 { "quiet",                 no_argument,       NULL, 'q'                   },
269                 { "share-system",          no_argument,       NULL, ARG_SHARE_SYSTEM      },
270                 { "register",              required_argument, NULL, ARG_REGISTER          },
271                 { "keep-unit",             no_argument,       NULL, ARG_KEEP_UNIT         },
272                 { "network-interface",     required_argument, NULL, ARG_NETWORK_INTERFACE },
273                 { "network-macvlan",       required_argument, NULL, ARG_NETWORK_MACVLAN   },
274                 { "network-veth",          no_argument,       NULL, ARG_NETWORK_VETH      },
275                 { "network-bridge",        required_argument, NULL, ARG_NETWORK_BRIDGE    },
276                 { "personality",           required_argument, NULL, ARG_PERSONALITY       },
277                 { "image",                 required_argument, NULL, 'i'                   },
278                 { "volatile",              optional_argument, NULL, ARG_VOLATILE          },
279                 {}
280         };
281
282         int c, r;
283         uint64_t plus = 0, minus = 0;
284
285         assert(argc >= 0);
286         assert(argv);
287
288         while ((c = getopt_long(argc, argv, "+hD:u:bL:M:jS:Z:qi:", options, NULL)) >= 0)
289
290                 switch (c) {
291
292                 case 'h':
293                         help();
294                         return 0;
295
296                 case ARG_VERSION:
297                         puts(PACKAGE_STRING);
298                         puts(SYSTEMD_FEATURES);
299                         return 0;
300
301                 case 'D':
302                         free(arg_directory);
303                         arg_directory = canonicalize_file_name(optarg);
304                         if (!arg_directory) {
305                                 log_error_errno(errno, "Invalid root directory: %m");
306                                 return -ENOMEM;
307                         }
308
309                         break;
310
311                 case 'i':
312                         arg_image = optarg;
313                         break;
314
315                 case 'u':
316                         free(arg_user);
317                         arg_user = strdup(optarg);
318                         if (!arg_user)
319                                 return log_oom();
320
321                         break;
322
323                 case ARG_NETWORK_BRIDGE:
324                         arg_network_bridge = optarg;
325
326                         /* fall through */
327
328                 case ARG_NETWORK_VETH:
329                         arg_network_veth = true;
330                         arg_private_network = true;
331                         break;
332
333                 case ARG_NETWORK_INTERFACE:
334                         if (strv_extend(&arg_network_interfaces, optarg) < 0)
335                                 return log_oom();
336
337                         arg_private_network = true;
338                         break;
339
340                 case ARG_NETWORK_MACVLAN:
341                         if (strv_extend(&arg_network_macvlan, optarg) < 0)
342                                 return log_oom();
343
344                         /* fall through */
345
346                 case ARG_PRIVATE_NETWORK:
347                         arg_private_network = true;
348                         break;
349
350                 case 'b':
351                         arg_boot = true;
352                         break;
353
354                 case ARG_UUID:
355                         r = sd_id128_from_string(optarg, &arg_uuid);
356                         if (r < 0) {
357                                 log_error("Invalid UUID: %s", optarg);
358                                 return r;
359                         }
360                         break;
361
362                 case 'S':
363                         arg_slice = optarg;
364                         break;
365
366                 case 'M':
367                         if (isempty(optarg)) {
368                                 free(arg_machine);
369                                 arg_machine = NULL;
370                         } else {
371
372                                 if (!hostname_is_valid(optarg)) {
373                                         log_error("Invalid machine name: %s", optarg);
374                                         return -EINVAL;
375                                 }
376
377                                 free(arg_machine);
378                                 arg_machine = strdup(optarg);
379                                 if (!arg_machine)
380                                         return log_oom();
381
382                                 break;
383                         }
384
385                 case 'Z':
386                         arg_selinux_context = optarg;
387                         break;
388
389                 case 'L':
390                         arg_selinux_apifs_context = optarg;
391                         break;
392
393                 case ARG_READ_ONLY:
394                         arg_read_only = true;
395                         break;
396
397                 case ARG_CAPABILITY:
398                 case ARG_DROP_CAPABILITY: {
399                         const char *state, *word;
400                         size_t length;
401
402                         FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
403                                 _cleanup_free_ char *t;
404                                 cap_value_t cap;
405
406                                 t = strndup(word, length);
407                                 if (!t)
408                                         return log_oom();
409
410                                 if (streq(t, "all")) {
411                                         if (c == ARG_CAPABILITY)
412                                                 plus = (uint64_t) -1;
413                                         else
414                                                 minus = (uint64_t) -1;
415                                 } else {
416                                         if (cap_from_name(t, &cap) < 0) {
417                                                 log_error("Failed to parse capability %s.", t);
418                                                 return -EINVAL;
419                                         }
420
421                                         if (c == ARG_CAPABILITY)
422                                                 plus |= 1ULL << (uint64_t) cap;
423                                         else
424                                                 minus |= 1ULL << (uint64_t) cap;
425                                 }
426                         }
427
428                         break;
429                 }
430
431                 case 'j':
432                         arg_link_journal = LINK_GUEST;
433                         arg_link_journal_try = true;
434                         break;
435
436                 case ARG_LINK_JOURNAL:
437                         if (streq(optarg, "auto"))
438                                 arg_link_journal = LINK_AUTO;
439                         else if (streq(optarg, "no"))
440                                 arg_link_journal = LINK_NO;
441                         else if (streq(optarg, "guest"))
442                                 arg_link_journal = LINK_GUEST;
443                         else if (streq(optarg, "host"))
444                                 arg_link_journal = LINK_HOST;
445                         else if (streq(optarg, "try-guest")) {
446                                 arg_link_journal = LINK_GUEST;
447                                 arg_link_journal_try = true;
448                         } else if (streq(optarg, "try-host")) {
449                                 arg_link_journal = LINK_HOST;
450                                 arg_link_journal_try = true;
451                         } else {
452                                 log_error("Failed to parse link journal mode %s", optarg);
453                                 return -EINVAL;
454                         }
455
456                         break;
457
458                 case ARG_BIND:
459                 case ARG_BIND_RO: {
460                         _cleanup_free_ char *a = NULL, *b = NULL;
461                         char *e;
462                         char ***x;
463
464                         x = c == ARG_BIND ? &arg_bind : &arg_bind_ro;
465
466                         e = strchr(optarg, ':');
467                         if (e) {
468                                 a = strndup(optarg, e - optarg);
469                                 b = strdup(e + 1);
470                         } else {
471                                 a = strdup(optarg);
472                                 b = strdup(optarg);
473                         }
474
475                         if (!a || !b)
476                                 return log_oom();
477
478                         if (!path_is_absolute(a) || !path_is_absolute(b)) {
479                                 log_error("Invalid bind mount specification: %s", optarg);
480                                 return -EINVAL;
481                         }
482
483                         r = strv_extend(x, a);
484                         if (r < 0)
485                                 return log_oom();
486
487                         r = strv_extend(x, b);
488                         if (r < 0)
489                                 return log_oom();
490
491                         break;
492                 }
493
494                 case ARG_TMPFS: {
495                         _cleanup_free_ char *a = NULL, *b = NULL;
496                         char *e;
497
498                         e = strchr(optarg, ':');
499                         if (e) {
500                                 a = strndup(optarg, e - optarg);
501                                 b = strdup(e + 1);
502                         } else {
503                                 a = strdup(optarg);
504                                 b = strdup("mode=0755");
505                         }
506
507                         if (!a || !b)
508                                 return log_oom();
509
510                         if (!path_is_absolute(a)) {
511                                 log_error("Invalid tmpfs specification: %s", optarg);
512                                 return -EINVAL;
513                         }
514
515                         r = strv_push(&arg_tmpfs, a);
516                         if (r < 0)
517                                 return log_oom();
518
519                         a = NULL;
520
521                         r = strv_push(&arg_tmpfs, b);
522                         if (r < 0)
523                                 return log_oom();
524
525                         b = NULL;
526
527                         break;
528                 }
529
530                 case ARG_SETENV: {
531                         char **n;
532
533                         if (!env_assignment_is_valid(optarg)) {
534                                 log_error("Environment variable assignment '%s' is not valid.", optarg);
535                                 return -EINVAL;
536                         }
537
538                         n = strv_env_set(arg_setenv, optarg);
539                         if (!n)
540                                 return log_oom();
541
542                         strv_free(arg_setenv);
543                         arg_setenv = n;
544                         break;
545                 }
546
547                 case 'q':
548                         arg_quiet = true;
549                         break;
550
551                 case ARG_SHARE_SYSTEM:
552                         arg_share_system = true;
553                         break;
554
555                 case ARG_REGISTER:
556                         r = parse_boolean(optarg);
557                         if (r < 0) {
558                                 log_error("Failed to parse --register= argument: %s", optarg);
559                                 return r;
560                         }
561
562                         arg_register = r;
563                         break;
564
565                 case ARG_KEEP_UNIT:
566                         arg_keep_unit = true;
567                         break;
568
569                 case ARG_PERSONALITY:
570
571                         arg_personality = personality_from_string(optarg);
572                         if (arg_personality == 0xffffffffLU) {
573                                 log_error("Unknown or unsupported personality '%s'.", optarg);
574                                 return -EINVAL;
575                         }
576
577                         break;
578
579                 case ARG_VOLATILE:
580
581                         if (!optarg)
582                                 arg_volatile = VOLATILE_YES;
583                         else {
584                                 r = parse_boolean(optarg);
585                                 if (r < 0) {
586                                         if (streq(optarg, "state"))
587                                                 arg_volatile = VOLATILE_STATE;
588                                         else {
589                                                 log_error("Failed to parse --volatile= argument: %s", optarg);
590                                                 return r;
591                                         }
592                                 } else
593                                         arg_volatile = r ? VOLATILE_YES : VOLATILE_NO;
594                         }
595
596                         break;
597
598                 case '?':
599                         return -EINVAL;
600
601                 default:
602                         assert_not_reached("Unhandled option");
603                 }
604
605         if (arg_share_system)
606                 arg_register = false;
607
608         if (arg_boot && arg_share_system) {
609                 log_error("--boot and --share-system may not be combined.");
610                 return -EINVAL;
611         }
612
613         if (arg_keep_unit && cg_pid_get_owner_uid(0, NULL) >= 0) {
614                 log_error("--keep-unit may not be used when invoked from a user session.");
615                 return -EINVAL;
616         }
617
618         if (arg_directory && arg_image) {
619                 log_error("--directory= and --image= may not be combined.");
620                 return -EINVAL;
621         }
622
623         if (arg_volatile != VOLATILE_NO && arg_read_only) {
624                 log_error("Cannot combine --read-only with --volatile. Note that --volatile already implies a read-only base hierarchy.");
625                 return -EINVAL;
626         }
627
628         arg_retain = (arg_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
629
630         return 1;
631 }
632
633 static int mount_all(const char *dest) {
634
635         typedef struct MountPoint {
636                 const char *what;
637                 const char *where;
638                 const char *type;
639                 const char *options;
640                 unsigned long flags;
641                 bool fatal;
642         } MountPoint;
643
644         static const MountPoint mount_table[] = {
645                 { "proc",      "/proc",     "proc",  NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV,           true  },
646                 { "/proc/sys", "/proc/sys", NULL,    NULL,        MS_BIND,                                true  },   /* Bind mount first */
647                 { NULL,        "/proc/sys", NULL,    NULL,        MS_BIND|MS_RDONLY|MS_REMOUNT,           true  },   /* Then, make it r/o */
648                 { "sysfs",     "/sys",      "sysfs", NULL,        MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, true  },
649                 { "tmpfs",     "/dev",      "tmpfs", "mode=755",  MS_NOSUID|MS_STRICTATIME,               true  },
650                 { "devpts",    "/dev/pts",  "devpts","newinstance,ptmxmode=0666,mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, true },
651                 { "tmpfs",     "/dev/shm",  "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME,      true  },
652                 { "tmpfs",     "/run",      "tmpfs", "mode=755",  MS_NOSUID|MS_NODEV|MS_STRICTATIME,      true  },
653 #ifdef HAVE_SELINUX
654                 { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND,                              false },  /* Bind mount first */
655                 { NULL,              "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT,         false },  /* Then, make it r/o */
656 #endif
657         };
658
659         unsigned k;
660         int r = 0;
661
662         for (k = 0; k < ELEMENTSOF(mount_table); k++) {
663                 _cleanup_free_ char *where = NULL;
664 #ifdef HAVE_SELINUX
665                 _cleanup_free_ char *options = NULL;
666 #endif
667                 const char *o;
668                 int t;
669
670                 where = strjoin(dest, "/", mount_table[k].where, NULL);
671                 if (!where)
672                         return log_oom();
673
674                 t = path_is_mount_point(where, true);
675                 if (t < 0) {
676                         log_error_errno(t, "Failed to detect whether %s is a mount point: %m", where);
677
678                         if (r == 0)
679                                 r = t;
680
681                         continue;
682                 }
683
684                 /* Skip this entry if it is not a remount. */
685                 if (mount_table[k].what && t > 0)
686                         continue;
687
688                 t = mkdir_p(where, 0755);
689                 if (t < 0) {
690                         if (mount_table[k].fatal) {
691                                log_error_errno(t, "Failed to create directory %s: %m", where);
692
693                                 if (r == 0)
694                                         r = t;
695                         } else
696                                log_warning_errno(t, "Failed to create directory %s: %m", where);
697
698                         continue;
699                 }
700
701 #ifdef HAVE_SELINUX
702                 if (arg_selinux_apifs_context &&
703                     (streq_ptr(mount_table[k].what, "tmpfs") || streq_ptr(mount_table[k].what, "devpts"))) {
704                         options = strjoin(mount_table[k].options, ",context=\"", arg_selinux_apifs_context, "\"", NULL);
705                         if (!options)
706                                 return log_oom();
707
708                         o = options;
709                 } else
710 #endif
711                         o = mount_table[k].options;
712
713
714                 if (mount(mount_table[k].what,
715                           where,
716                           mount_table[k].type,
717                           mount_table[k].flags,
718                           o) < 0) {
719
720                         if (mount_table[k].fatal) {
721                                 log_error_errno(errno, "mount(%s) failed: %m", where);
722
723                                 if (r == 0)
724                                         r = -errno;
725                         } else
726                                 log_warning_errno(errno, "mount(%s) failed: %m", where);
727                 }
728         }
729
730         return r;
731 }
732
733 static int mount_binds(const char *dest, char **l, bool ro) {
734         char **x, **y;
735
736         STRV_FOREACH_PAIR(x, y, l) {
737                 _cleanup_free_ char *where = NULL;
738                 struct stat source_st, dest_st;
739                 int r;
740
741                 if (stat(*x, &source_st) < 0)
742                         return log_error_errno(errno, "Failed to stat %s: %m", *x);
743
744                 where = strappend(dest, *y);
745                 if (!where)
746                         return log_oom();
747
748                 r = stat(where, &dest_st);
749                 if (r == 0) {
750                         if ((source_st.st_mode & S_IFMT) != (dest_st.st_mode & S_IFMT)) {
751                                 log_error("The file types of %s and %s do not match. Refusing bind mount", *x, where);
752                                 return -EINVAL;
753                         }
754                 } else if (errno == ENOENT) {
755                         r = mkdir_parents_label(where, 0755);
756                         if (r < 0)
757                                 return log_error_errno(r, "Failed to bind mount %s: %m", *x);
758                 } else {
759                         log_error_errno(errno, "Failed to bind mount %s: %m", *x);
760                         return -errno;
761                 }
762
763                 /* Create the mount point, but be conservative -- refuse to create block
764                  * and char devices. */
765                 if (S_ISDIR(source_st.st_mode)) {
766                         r = mkdir_label(where, 0755);
767                         if (r < 0 && errno != EEXIST)
768                                 return log_error_errno(r, "Failed to create mount point %s: %m", where);
769                 } else if (S_ISFIFO(source_st.st_mode)) {
770                         r = mkfifo(where, 0644);
771                         if (r < 0 && errno != EEXIST)
772                                 return log_error_errno(errno, "Failed to create mount point %s: %m", where);
773                 } else if (S_ISSOCK(source_st.st_mode)) {
774                         r = mknod(where, 0644 | S_IFSOCK, 0);
775                         if (r < 0 && errno != EEXIST)
776                                 return log_error_errno(errno, "Failed to create mount point %s: %m", where);
777                 } else if (S_ISREG(source_st.st_mode)) {
778                         r = touch(where);
779                         if (r < 0)
780                                 return log_error_errno(r, "Failed to create mount point %s: %m", where);
781                 } else {
782                         log_error("Refusing to create mountpoint for file: %s", *x);
783                         return -ENOTSUP;
784                 }
785
786                 if (mount(*x, where, "bind", MS_BIND, NULL) < 0)
787                         return log_error_errno(errno, "mount(%s) failed: %m", where);
788
789                 if (ro) {
790                         r = bind_remount_recursive(where, true);
791                         if (r < 0)
792                                 return log_error_errno(r, "Read-Only bind mount failed: %m");
793                 }
794         }
795
796         return 0;
797 }
798
799 static int mount_tmpfs(const char *dest) {
800         char **i, **o;
801
802         STRV_FOREACH_PAIR(i, o, arg_tmpfs) {
803                 _cleanup_free_ char *where = NULL;
804                 int r;
805
806                 where = strappend(dest, *i);
807                 if (!where)
808                         return log_oom();
809
810                 r = mkdir_label(where, 0755);
811                 if (r < 0 && errno != EEXIST)
812                         return log_error_errno(r, "creating mount point for tmpfs %s failed: %m", where);
813
814                 if (mount("tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, *o) < 0)
815                         return log_error_errno(errno, "tmpfs mount to %s failed: %m", where);
816         }
817
818         return 0;
819 }
820
821 static int setup_timezone(const char *dest) {
822         _cleanup_free_ char *where = NULL, *p = NULL, *q = NULL, *check = NULL, *what = NULL;
823         char *z, *y;
824         int r;
825
826         assert(dest);
827
828         /* Fix the timezone, if possible */
829         r = readlink_malloc("/etc/localtime", &p);
830         if (r < 0) {
831                 log_warning("/etc/localtime is not a symlink, not updating container timezone.");
832                 return 0;
833         }
834
835         z = path_startswith(p, "../usr/share/zoneinfo/");
836         if (!z)
837                 z = path_startswith(p, "/usr/share/zoneinfo/");
838         if (!z) {
839                 log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
840                 return 0;
841         }
842
843         where = strappend(dest, "/etc/localtime");
844         if (!where)
845                 return log_oom();
846
847         r = readlink_malloc(where, &q);
848         if (r >= 0) {
849                 y = path_startswith(q, "../usr/share/zoneinfo/");
850                 if (!y)
851                         y = path_startswith(q, "/usr/share/zoneinfo/");
852
853                 /* Already pointing to the right place? Then do nothing .. */
854                 if (y && streq(y, z))
855                         return 0;
856         }
857
858         check = strjoin(dest, "/usr/share/zoneinfo/", z, NULL);
859         if (!check)
860                 return log_oom();
861
862         if (access(check, F_OK) < 0) {
863                 log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
864                 return 0;
865         }
866
867         what = strappend("../usr/share/zoneinfo/", z);
868         if (!what)
869                 return log_oom();
870
871         r = mkdir_parents(where, 0755);
872         if (r < 0) {
873                 log_error_errno(r, "Failed to create directory for timezone info %s in container: %m", where);
874
875                 return 0;
876         }
877
878         r = unlink(where);
879         if (r < 0 && errno != ENOENT) {
880                 log_error_errno(errno, "Failed to remove existing timezone info %s in container: %m", where);
881
882                 return 0;
883         }
884
885         if (symlink(what, where) < 0) {
886                 log_error_errno(errno, "Failed to correct timezone of container: %m");
887                 return 0;
888         }
889
890         return 0;
891 }
892
893 static int setup_resolv_conf(const char *dest) {
894         _cleanup_free_ char *where = NULL;
895         int r;
896
897         assert(dest);
898
899         if (arg_private_network)
900                 return 0;
901
902         /* Fix resolv.conf, if possible */
903         where = strappend(dest, "/etc/resolv.conf");
904         if (!where)
905                 return log_oom();
906
907         /* We don't really care for the results of this really. If it
908          * fails, it fails, but meh... */
909         r = mkdir_parents(where, 0755);
910         if (r < 0) {
911                 log_warning_errno(r, "Failed to create parent directory for resolv.conf %s: %m", where);
912
913                 return 0;
914         }
915
916         r = copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW, 0644);
917         if (r < 0) {
918                 log_warning_errno(r, "Failed to copy /etc/resolv.conf to %s: %m", where);
919
920                 return 0;
921         }
922
923         return 0;
924 }
925
926 static int setup_volatile_state(const char *directory) {
927         const char *p;
928         int r;
929
930         assert(directory);
931
932         if (arg_volatile != VOLATILE_STATE)
933                 return 0;
934
935         /* --volatile=state means we simply overmount /var
936            with a tmpfs, and the rest read-only. */
937
938         r = bind_remount_recursive(directory, true);
939         if (r < 0)
940                 return log_error_errno(r, "Failed to remount %s read-only: %m", directory);
941
942         p = strappenda(directory, "/var");
943         r = mkdir(p, 0755);
944         if (r < 0 && errno != EEXIST)
945                 return log_error_errno(errno, "Failed to create %s: %m", directory);
946
947         if (mount("tmpfs", p, "tmpfs", MS_STRICTATIME, "mode=755") < 0)
948                 return log_error_errno(errno, "Failed to mount tmpfs to /var: %m");
949
950         return 0;
951 }
952
953 static int setup_volatile(const char *directory) {
954         bool tmpfs_mounted = false, bind_mounted = false;
955         char template[] = "/tmp/nspawn-volatile-XXXXXX";
956         const char *f, *t;
957         int r;
958
959         assert(directory);
960
961         if (arg_volatile != VOLATILE_YES)
962                 return 0;
963
964         /* --volatile=yes means we mount a tmpfs to the root dir, and
965            the original /usr to use inside it, and that read-only. */
966
967         if (!mkdtemp(template))
968                 return log_error_errno(errno, "Failed to create temporary directory: %m");
969
970         if (mount("tmpfs", template, "tmpfs", MS_STRICTATIME, "mode=755") < 0) {
971                 log_error_errno(errno, "Failed to mount tmpfs for root directory: %m");
972                 r = -errno;
973                 goto fail;
974         }
975
976         tmpfs_mounted = true;
977
978         f = strappenda(directory, "/usr");
979         t = strappenda(template, "/usr");
980
981         r = mkdir(t, 0755);
982         if (r < 0 && errno != EEXIST) {
983                 log_error_errno(errno, "Failed to create %s: %m", t);
984                 r = -errno;
985                 goto fail;
986         }
987
988         if (mount(f, t, "bind", MS_BIND|MS_REC, NULL) < 0) {
989                 log_error_errno(errno, "Failed to create /usr bind mount: %m");
990                 r = -errno;
991                 goto fail;
992         }
993
994         bind_mounted = true;
995
996         r = bind_remount_recursive(t, true);
997         if (r < 0) {
998                 log_error_errno(r, "Failed to remount %s read-only: %m", t);
999                 goto fail;
1000         }
1001
1002         if (mount(template, directory, NULL, MS_MOVE, NULL) < 0) {
1003                 log_error_errno(errno, "Failed to move root mount: %m");
1004                 r = -errno;
1005                 goto fail;
1006         }
1007
1008         rmdir(template);
1009
1010         return 0;
1011
1012 fail:
1013         if (bind_mounted)
1014                 umount(t);
1015         if (tmpfs_mounted)
1016                 umount(template);
1017         rmdir(template);
1018         return r;
1019 }
1020
1021 static char* id128_format_as_uuid(sd_id128_t id, char s[37]) {
1022
1023         snprintf(s, 37,
1024                  "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1025                  SD_ID128_FORMAT_VAL(id));
1026
1027         return s;
1028 }
1029
1030 static int setup_boot_id(const char *dest) {
1031         _cleanup_free_ char *from = NULL, *to = NULL;
1032         sd_id128_t rnd = {};
1033         char as_uuid[37];
1034         int r;
1035
1036         assert(dest);
1037
1038         if (arg_share_system)
1039                 return 0;
1040
1041         /* Generate a new randomized boot ID, so that each boot-up of
1042          * the container gets a new one */
1043
1044         from = strappend(dest, "/dev/proc-sys-kernel-random-boot-id");
1045         to = strappend(dest, "/proc/sys/kernel/random/boot_id");
1046         if (!from || !to)
1047                 return log_oom();
1048
1049         r = sd_id128_randomize(&rnd);
1050         if (r < 0)
1051                 return log_error_errno(r, "Failed to generate random boot id: %m");
1052
1053         id128_format_as_uuid(rnd, as_uuid);
1054
1055         r = write_string_file(from, as_uuid);
1056         if (r < 0)
1057                 return log_error_errno(r, "Failed to write boot id: %m");
1058
1059         if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
1060                 log_error_errno(errno, "Failed to bind mount boot id: %m");
1061                 r = -errno;
1062         } else if (mount(from, to, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL))
1063                 log_warning_errno(errno, "Failed to make boot id read-only: %m");
1064
1065         unlink(from);
1066         return r;
1067 }
1068
1069 static int copy_devnodes(const char *dest) {
1070
1071         static const char devnodes[] =
1072                 "null\0"
1073                 "zero\0"
1074                 "full\0"
1075                 "random\0"
1076                 "urandom\0"
1077                 "tty\0"
1078                 "net/tun\0";
1079
1080         const char *d;
1081         int r = 0;
1082         _cleanup_umask_ mode_t u;
1083
1084         assert(dest);
1085
1086         u = umask(0000);
1087
1088         NULSTR_FOREACH(d, devnodes) {
1089                 _cleanup_free_ char *from = NULL, *to = NULL;
1090                 struct stat st;
1091
1092                 from = strappend("/dev/", d);
1093                 to = strjoin(dest, "/dev/", d, NULL);
1094                 if (!from || !to)
1095                         return log_oom();
1096
1097                 if (stat(from, &st) < 0) {
1098
1099                         if (errno != ENOENT)
1100                                 return log_error_errno(errno, "Failed to stat %s: %m", from);
1101
1102                 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
1103
1104                         log_error("%s is not a char or block device, cannot copy", from);
1105                         return -EIO;
1106
1107                 } else {
1108                         r = mkdir_parents(to, 0775);
1109                         if (r < 0) {
1110                                 log_error_errno(r, "Failed to create parent directory of %s: %m", to);
1111                                 return -r;
1112                         }
1113
1114                         if (mknod(to, st.st_mode, st.st_rdev) < 0)
1115                                 return log_error_errno(errno, "mknod(%s) failed: %m", dest);
1116                 }
1117         }
1118
1119         return r;
1120 }
1121
1122 static int setup_ptmx(const char *dest) {
1123         _cleanup_free_ char *p = NULL;
1124
1125         p = strappend(dest, "/dev/ptmx");
1126         if (!p)
1127                 return log_oom();
1128
1129         if (symlink("pts/ptmx", p) < 0)
1130                 return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m");
1131
1132         return 0;
1133 }
1134
1135 static int setup_dev_console(const char *dest, const char *console) {
1136         _cleanup_umask_ mode_t u;
1137         const char *to;
1138         struct stat st;
1139         int r;
1140
1141         assert(dest);
1142         assert(console);
1143
1144         u = umask(0000);
1145
1146         if (stat("/dev/null", &st) < 0)
1147                 return log_error_errno(errno, "Failed to stat /dev/null: %m");
1148
1149         r = chmod_and_chown(console, 0600, 0, 0);
1150         if (r < 0)
1151                 return log_error_errno(r, "Failed to correct access mode for TTY: %m");
1152
1153         /* We need to bind mount the right tty to /dev/console since
1154          * ptys can only exist on pts file systems. To have something
1155          * to bind mount things on we create a device node first, and
1156          * use /dev/null for that since we the cgroups device policy
1157          * allows us to create that freely, while we cannot create
1158          * /dev/console. (Note that the major minor doesn't actually
1159          * matter here, since we mount it over anyway). */
1160
1161         to = strappenda(dest, "/dev/console");
1162         if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0)
1163                 return log_error_errno(errno, "mknod() for /dev/console failed: %m");
1164
1165         if (mount(console, to, "bind", MS_BIND, NULL) < 0)
1166                 return log_error_errno(errno, "Bind mount for /dev/console failed: %m");
1167
1168         return 0;
1169 }
1170
1171 static int setup_kmsg(const char *dest, int kmsg_socket) {
1172         _cleanup_free_ char *from = NULL, *to = NULL;
1173         int r, fd, k;
1174         _cleanup_umask_ mode_t u;
1175         union {
1176                 struct cmsghdr cmsghdr;
1177                 uint8_t buf[CMSG_SPACE(sizeof(int))];
1178         } control = {};
1179         struct msghdr mh = {
1180                 .msg_control = &control,
1181                 .msg_controllen = sizeof(control),
1182         };
1183         struct cmsghdr *cmsg;
1184
1185         assert(dest);
1186         assert(kmsg_socket >= 0);
1187
1188         u = umask(0000);
1189
1190         /* We create the kmsg FIFO as /dev/kmsg, but immediately
1191          * delete it after bind mounting it to /proc/kmsg. While FIFOs
1192          * on the reading side behave very similar to /proc/kmsg,
1193          * their writing side behaves differently from /dev/kmsg in
1194          * that writing blocks when nothing is reading. In order to
1195          * avoid any problems with containers deadlocking due to this
1196          * we simply make /dev/kmsg unavailable to the container. */
1197         if (asprintf(&from, "%s/dev/kmsg", dest) < 0 ||
1198             asprintf(&to, "%s/proc/kmsg", dest) < 0)
1199                 return log_oom();
1200
1201         if (mkfifo(from, 0600) < 0)
1202                 return log_error_errno(errno, "mkfifo() for /dev/kmsg failed: %m");
1203
1204         r = chmod_and_chown(from, 0600, 0, 0);
1205         if (r < 0)
1206                 return log_error_errno(r, "Failed to correct access mode for /dev/kmsg: %m");
1207
1208         if (mount(from, to, "bind", MS_BIND, NULL) < 0)
1209                 return log_error_errno(errno, "Bind mount for /proc/kmsg failed: %m");
1210
1211         fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
1212         if (fd < 0)
1213                 return log_error_errno(errno, "Failed to open fifo: %m");
1214
1215         cmsg = CMSG_FIRSTHDR(&mh);
1216         cmsg->cmsg_level = SOL_SOCKET;
1217         cmsg->cmsg_type = SCM_RIGHTS;
1218         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
1219         memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
1220
1221         mh.msg_controllen = cmsg->cmsg_len;
1222
1223         /* Store away the fd in the socket, so that it stays open as
1224          * long as we run the child */
1225         k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
1226         safe_close(fd);
1227
1228         if (k < 0)
1229                 return log_error_errno(errno, "Failed to send FIFO fd: %m");
1230
1231         /* And now make the FIFO unavailable as /dev/kmsg... */
1232         unlink(from);
1233         return 0;
1234 }
1235
1236 static int setup_hostname(void) {
1237
1238         if (arg_share_system)
1239                 return 0;
1240
1241         if (sethostname_idempotent(arg_machine) < 0)
1242                 return -errno;
1243
1244         return 0;
1245 }
1246
1247 static int setup_journal(const char *directory) {
1248         sd_id128_t machine_id, this_id;
1249         _cleanup_free_ char *p = NULL, *b = NULL, *q = NULL, *d = NULL;
1250         char *id;
1251         int r;
1252
1253         p = strappend(directory, "/etc/machine-id");
1254         if (!p)
1255                 return log_oom();
1256
1257         r = read_one_line_file(p, &b);
1258         if (r == -ENOENT && arg_link_journal == LINK_AUTO)
1259                 return 0;
1260         else if (r < 0)
1261                 return log_error_errno(r, "Failed to read machine ID from %s: %m", p);
1262
1263         id = strstrip(b);
1264         if (isempty(id) && arg_link_journal == LINK_AUTO)
1265                 return 0;
1266
1267         /* Verify validity */
1268         r = sd_id128_from_string(id, &machine_id);
1269         if (r < 0)
1270                 return log_error_errno(r, "Failed to parse machine ID from %s: %m", p);
1271
1272         r = sd_id128_get_machine(&this_id);
1273         if (r < 0)
1274                 return log_error_errno(r, "Failed to retrieve machine ID: %m");
1275
1276         if (sd_id128_equal(machine_id, this_id)) {
1277                 log_full(arg_link_journal == LINK_AUTO ? LOG_WARNING : LOG_ERR,
1278                          "Host and machine ids are equal (%s): refusing to link journals", id);
1279                 if (arg_link_journal == LINK_AUTO)
1280                         return 0;
1281                 return
1282                         -EEXIST;
1283         }
1284
1285         if (arg_link_journal == LINK_NO)
1286                 return 0;
1287
1288         free(p);
1289         p = strappend("/var/log/journal/", id);
1290         q = strjoin(directory, "/var/log/journal/", id, NULL);
1291         if (!p || !q)
1292                 return log_oom();
1293
1294         if (path_is_mount_point(p, false) > 0) {
1295                 if (arg_link_journal != LINK_AUTO) {
1296                         log_error("%s: already a mount point, refusing to use for journal", p);
1297                         return -EEXIST;
1298                 }
1299
1300                 return 0;
1301         }
1302
1303         if (path_is_mount_point(q, false) > 0) {
1304                 if (arg_link_journal != LINK_AUTO) {
1305                         log_error("%s: already a mount point, refusing to use for journal", q);
1306                         return -EEXIST;
1307                 }
1308
1309                 return 0;
1310         }
1311
1312         r = readlink_and_make_absolute(p, &d);
1313         if (r >= 0) {
1314                 if ((arg_link_journal == LINK_GUEST ||
1315                      arg_link_journal == LINK_AUTO) &&
1316                     path_equal(d, q)) {
1317
1318                         r = mkdir_p(q, 0755);
1319                         if (r < 0)
1320                                 log_warning_errno(errno, "Failed to create directory %s: %m", q);
1321                         return 0;
1322                 }
1323
1324                 if (unlink(p) < 0)
1325                         return log_error_errno(errno, "Failed to remove symlink %s: %m", p);
1326         } else if (r == -EINVAL) {
1327
1328                 if (arg_link_journal == LINK_GUEST &&
1329                     rmdir(p) < 0) {
1330
1331                         if (errno == ENOTDIR) {
1332                                 log_error("%s already exists and is neither a symlink nor a directory", p);
1333                                 return r;
1334                         } else {
1335                                 log_error_errno(errno, "Failed to remove %s: %m", p);
1336                                 return -errno;
1337                         }
1338                 }
1339         } else if (r != -ENOENT) {
1340                 log_error_errno(errno, "readlink(%s) failed: %m", p);
1341                 return r;
1342         }
1343
1344         if (arg_link_journal == LINK_GUEST) {
1345
1346                 if (symlink(q, p) < 0) {
1347                         if (arg_link_journal_try) {
1348                                 log_debug_errno(errno, "Failed to symlink %s to %s, skipping journal setup: %m", q, p);
1349                                 return 0;
1350                         } else {
1351                                 log_error_errno(errno, "Failed to symlink %s to %s: %m", q, p);
1352                                 return -errno;
1353                         }
1354                 }
1355
1356                 r = mkdir_p(q, 0755);
1357                 if (r < 0)
1358                         log_warning_errno(errno, "Failed to create directory %s: %m", q);
1359                 return 0;
1360         }
1361
1362         if (arg_link_journal == LINK_HOST) {
1363                 /* don't create parents here -- if the host doesn't have
1364                  * permanent journal set up, don't force it here */
1365                 r = mkdir(p, 0755);
1366                 if (r < 0) {
1367                         if (arg_link_journal_try) {
1368                                 log_debug_errno(errno, "Failed to create %s, skipping journal setup: %m", p);
1369                                 return 0;
1370                         } else {
1371                                 log_error_errno(errno, "Failed to create %s: %m", p);
1372                                 return r;
1373                         }
1374                 }
1375
1376         } else if (access(p, F_OK) < 0)
1377                 return 0;
1378
1379         if (dir_is_empty(q) == 0)
1380                 log_warning("%s is not empty, proceeding anyway.", q);
1381
1382         r = mkdir_p(q, 0755);
1383         if (r < 0) {
1384                 log_error_errno(errno, "Failed to create %s: %m", q);
1385                 return r;
1386         }
1387
1388         if (mount(p, q, "bind", MS_BIND, NULL) < 0)
1389                 return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m");
1390
1391         return 0;
1392 }
1393
1394 static int drop_capabilities(void) {
1395         return capability_bounding_set_drop(~arg_retain, false);
1396 }
1397
1398 static int register_machine(pid_t pid, int local_ifindex) {
1399         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
1400         _cleanup_bus_close_unref_ sd_bus *bus = NULL;
1401         int r;
1402
1403         if (!arg_register)
1404                 return 0;
1405
1406         r = sd_bus_default_system(&bus);
1407         if (r < 0)
1408                 return log_error_errno(r, "Failed to open system bus: %m");
1409
1410         if (arg_keep_unit) {
1411                 r = sd_bus_call_method(
1412                                 bus,
1413                                 "org.freedesktop.machine1",
1414                                 "/org/freedesktop/machine1",
1415                                 "org.freedesktop.machine1.Manager",
1416                                 "RegisterMachineWithNetwork",
1417                                 &error,
1418                                 NULL,
1419                                 "sayssusai",
1420                                 arg_machine,
1421                                 SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
1422                                 "nspawn",
1423                                 "container",
1424                                 (uint32_t) pid,
1425                                 strempty(arg_directory),
1426                                 local_ifindex > 0 ? 1 : 0, local_ifindex);
1427         } else {
1428                 _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
1429
1430                 r = sd_bus_message_new_method_call(
1431                                 bus,
1432                                 &m,
1433                                 "org.freedesktop.machine1",
1434                                 "/org/freedesktop/machine1",
1435                                 "org.freedesktop.machine1.Manager",
1436                                 "CreateMachineWithNetwork");
1437                 if (r < 0)
1438                         return log_error_errno(r, "Failed to create message: %m");
1439
1440                 r = sd_bus_message_append(
1441                                 m,
1442                                 "sayssusai",
1443                                 arg_machine,
1444                                 SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
1445                                 "nspawn",
1446                                 "container",
1447                                 (uint32_t) pid,
1448                                 strempty(arg_directory),
1449                                 local_ifindex > 0 ? 1 : 0, local_ifindex);
1450                 if (r < 0)
1451                         return log_error_errno(r, "Failed to append message arguments: %m");
1452
1453                 r = sd_bus_message_open_container(m, 'a', "(sv)");
1454                 if (r < 0)
1455                         return log_error_errno(r, "Failed to open container: %m");
1456
1457                 if (!isempty(arg_slice)) {
1458                         r = sd_bus_message_append(m, "(sv)", "Slice", "s", arg_slice);
1459                         if (r < 0)
1460                                 return log_error_errno(r, "Failed to append slice: %m");
1461                 }
1462
1463                 r = sd_bus_message_append(m, "(sv)", "DevicePolicy", "s", "strict");
1464                 if (r < 0)
1465                         return log_error_errno(r, "Failed to add device policy: %m");
1466
1467                 r = sd_bus_message_append(m, "(sv)", "DeviceAllow", "a(ss)", 9,
1468                                           /* Allow the container to
1469                                            * access and create the API
1470                                            * device nodes, so that
1471                                            * PrivateDevices= in the
1472                                            * container can work
1473                                            * fine */
1474                                           "/dev/null", "rwm",
1475                                           "/dev/zero", "rwm",
1476                                           "/dev/full", "rwm",
1477                                           "/dev/random", "rwm",
1478                                           "/dev/urandom", "rwm",
1479                                           "/dev/tty", "rwm",
1480                                           "/dev/net/tun", "rwm",
1481                                           /* Allow the container
1482                                            * access to ptys. However,
1483                                            * do not permit the
1484                                            * container to ever create
1485                                            * these device nodes. */
1486                                           "/dev/pts/ptmx", "rw",
1487                                           "char-pts", "rw");
1488                 if (r < 0)
1489                         return log_error_errno(r, "Failed to add device whitelist: %m");
1490
1491                 r = sd_bus_message_close_container(m);
1492                 if (r < 0)
1493                         return log_error_errno(r, "Failed to close container: %m");
1494
1495                 r = sd_bus_call(bus, m, 0, &error, NULL);
1496         }
1497
1498         if (r < 0) {
1499                 log_error("Failed to register machine: %s", bus_error_message(&error, r));
1500                 return r;
1501         }
1502
1503         return 0;
1504 }
1505
1506 static int terminate_machine(pid_t pid) {
1507         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
1508         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
1509         _cleanup_bus_close_unref_ sd_bus *bus = NULL;
1510         const char *path;
1511         int r;
1512
1513         if (!arg_register)
1514                 return 0;
1515
1516         r = sd_bus_default_system(&bus);
1517         if (r < 0)
1518                 return log_error_errno(r, "Failed to open system bus: %m");
1519
1520         r = sd_bus_call_method(
1521                         bus,
1522                         "org.freedesktop.machine1",
1523                         "/org/freedesktop/machine1",
1524                         "org.freedesktop.machine1.Manager",
1525                         "GetMachineByPID",
1526                         &error,
1527                         &reply,
1528                         "u",
1529                         (uint32_t) pid);
1530         if (r < 0) {
1531                 /* Note that the machine might already have been
1532                  * cleaned up automatically, hence don't consider it a
1533                  * failure if we cannot get the machine object. */
1534                 log_debug("Failed to get machine: %s", bus_error_message(&error, r));
1535                 return 0;
1536         }
1537
1538         r = sd_bus_message_read(reply, "o", &path);
1539         if (r < 0)
1540                 return bus_log_parse_error(r);
1541
1542         r = sd_bus_call_method(
1543                         bus,
1544                         "org.freedesktop.machine1",
1545                         path,
1546                         "org.freedesktop.machine1.Machine",
1547                         "Terminate",
1548                         &error,
1549                         NULL,
1550                         NULL);
1551         if (r < 0) {
1552                 log_debug("Failed to terminate machine: %s", bus_error_message(&error, r));
1553                 return 0;
1554         }
1555
1556         return 0;
1557 }
1558
1559 static int reset_audit_loginuid(void) {
1560         _cleanup_free_ char *p = NULL;
1561         int r;
1562
1563         if (arg_share_system)
1564                 return 0;
1565
1566         r = read_one_line_file("/proc/self/loginuid", &p);
1567         if (r == -ENOENT)
1568                 return 0;
1569         if (r < 0)
1570                 return log_error_errno(r, "Failed to read /proc/self/loginuid: %m");
1571
1572         /* Already reset? */
1573         if (streq(p, "4294967295"))
1574                 return 0;
1575
1576         r = write_string_file("/proc/self/loginuid", "4294967295");
1577         if (r < 0) {
1578                 log_error("Failed to reset audit login UID. This probably means that your kernel is too\n"
1579                           "old and you have audit enabled. Note that the auditing subsystem is known to\n"
1580                           "be incompatible with containers on old kernels. Please make sure to upgrade\n"
1581                           "your kernel or to off auditing with 'audit=0' on the kernel command line before\n"
1582                           "using systemd-nspawn. Sleeping for 5s... (%s)\n", strerror(-r));
1583
1584                 sleep(5);
1585         }
1586
1587         return 0;
1588 }
1589
1590 #define HOST_HASH_KEY SD_ID128_MAKE(1a,37,6f,c7,46,ec,45,0b,ad,a3,d5,31,06,60,5d,b1)
1591 #define CONTAINER_HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2)
1592
1593 static int generate_mac(struct ether_addr *mac, sd_id128_t hash_key) {
1594         int r;
1595
1596         uint8_t result[8];
1597         size_t l, sz;
1598         uint8_t *v;
1599
1600         l = strlen(arg_machine);
1601         sz = sizeof(sd_id128_t) + l;
1602         v = alloca(sz);
1603
1604         /* fetch some persistent data unique to the host */
1605         r = sd_id128_get_machine((sd_id128_t*) v);
1606         if (r < 0)
1607                 return r;
1608
1609         /* combine with some data unique (on this host) to this
1610          * container instance */
1611         memcpy(v + sizeof(sd_id128_t), arg_machine, l);
1612
1613         /* Let's hash the host machine ID plus the container name. We
1614          * use a fixed, but originally randomly created hash key here. */
1615         siphash24(result, v, sz, hash_key.bytes);
1616
1617         assert_cc(ETH_ALEN <= sizeof(result));
1618         memcpy(mac->ether_addr_octet, result, ETH_ALEN);
1619
1620         /* see eth_random_addr in the kernel */
1621         mac->ether_addr_octet[0] &= 0xfe;        /* clear multicast bit */
1622         mac->ether_addr_octet[0] |= 0x02;        /* set local assignment bit (IEEE802) */
1623
1624         return 0;
1625 }
1626
1627 static int setup_veth(pid_t pid, char iface_name[IFNAMSIZ], int *ifi) {
1628         _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
1629         _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
1630         struct ether_addr mac_host, mac_container;
1631         int r, i;
1632
1633         if (!arg_private_network)
1634                 return 0;
1635
1636         if (!arg_network_veth)
1637                 return 0;
1638
1639         /* Use two different interface name prefixes depending whether
1640          * we are in bridge mode or not. */
1641         snprintf(iface_name, IFNAMSIZ - 1, "%s-%s",
1642                  arg_network_bridge ? "vb" : "ve", arg_machine);
1643
1644         r = generate_mac(&mac_container, CONTAINER_HASH_KEY);
1645         if (r < 0) {
1646                 log_error("Failed to generate predictable MAC address for container side");
1647                 return r;
1648         }
1649
1650         r = generate_mac(&mac_host, HOST_HASH_KEY);
1651         if (r < 0) {
1652                 log_error("Failed to generate predictable MAC address for host side");
1653                 return r;
1654         }
1655
1656         r = sd_rtnl_open(&rtnl, 0);
1657         if (r < 0)
1658                 return log_error_errno(r, "Failed to connect to netlink: %m");
1659
1660         r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
1661         if (r < 0)
1662                 return log_error_errno(r, "Failed to allocate netlink message: %m");
1663
1664         r = sd_rtnl_message_append_string(m, IFLA_IFNAME, iface_name);
1665         if (r < 0)
1666                 return log_error_errno(r, "Failed to add netlink interface name: %m");
1667
1668         r = sd_rtnl_message_append_ether_addr(m, IFLA_ADDRESS, &mac_host);
1669         if (r < 0)
1670                 return log_error_errno(r, "Failed to add netlink MAC address: %m");
1671
1672         r = sd_rtnl_message_open_container(m, IFLA_LINKINFO);
1673         if (r < 0)
1674                 return log_error_errno(r, "Failed to open netlink container: %m");
1675
1676         r = sd_rtnl_message_open_container_union(m, IFLA_INFO_DATA, "veth");
1677         if (r < 0)
1678                 return log_error_errno(r, "Failed to open netlink container: %m");
1679
1680         r = sd_rtnl_message_open_container(m, VETH_INFO_PEER);
1681         if (r < 0)
1682                 return log_error_errno(r, "Failed to open netlink container: %m");
1683
1684         r = sd_rtnl_message_append_string(m, IFLA_IFNAME, "host0");
1685         if (r < 0)
1686                 return log_error_errno(r, "Failed to add netlink interface name: %m");
1687
1688         r = sd_rtnl_message_append_ether_addr(m, IFLA_ADDRESS, &mac_container);
1689         if (r < 0)
1690                 return log_error_errno(r, "Failed to add netlink MAC address: %m");
1691
1692         r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid);
1693         if (r < 0)
1694                 return log_error_errno(r, "Failed to add netlink namespace field: %m");
1695
1696         r = sd_rtnl_message_close_container(m);
1697         if (r < 0)
1698                 return log_error_errno(r, "Failed to close netlink container: %m");
1699
1700         r = sd_rtnl_message_close_container(m);
1701         if (r < 0)
1702                 return log_error_errno(r, "Failed to close netlink container: %m");
1703
1704         r = sd_rtnl_message_close_container(m);
1705         if (r < 0)
1706                 return log_error_errno(r, "Failed to close netlink container: %m");
1707
1708         r = sd_rtnl_call(rtnl, m, 0, NULL);
1709         if (r < 0)
1710                 return log_error_errno(r, "Failed to add new veth interfaces: %m");
1711
1712         i = (int) if_nametoindex(iface_name);
1713         if (i <= 0)
1714                 return log_error_errno(errno, "Failed to resolve interface %s: %m", iface_name);
1715
1716         *ifi = i;
1717
1718         return 0;
1719 }
1720
1721 static int setup_bridge(const char veth_name[], int *ifi) {
1722         _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
1723         _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
1724         int r, bridge;
1725
1726         if (!arg_private_network)
1727                 return 0;
1728
1729         if (!arg_network_veth)
1730                 return 0;
1731
1732         if (!arg_network_bridge)
1733                 return 0;
1734
1735         bridge = (int) if_nametoindex(arg_network_bridge);
1736         if (bridge <= 0)
1737                 return log_error_errno(errno, "Failed to resolve interface %s: %m", arg_network_bridge);
1738
1739         *ifi = bridge;
1740
1741         r = sd_rtnl_open(&rtnl, 0);
1742         if (r < 0)
1743                 return log_error_errno(r, "Failed to connect to netlink: %m");
1744
1745         r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
1746         if (r < 0)
1747                 return log_error_errno(r, "Failed to allocate netlink message: %m");
1748
1749         r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
1750         if (r < 0)
1751                 return log_error_errno(r, "Failed to set IFF_UP flag: %m");
1752
1753         r = sd_rtnl_message_append_string(m, IFLA_IFNAME, veth_name);
1754         if (r < 0)
1755                 return log_error_errno(r, "Failed to add netlink interface name field: %m");
1756
1757         r = sd_rtnl_message_append_u32(m, IFLA_MASTER, bridge);
1758         if (r < 0)
1759                 return log_error_errno(r, "Failed to add netlink master field: %m");
1760
1761         r = sd_rtnl_call(rtnl, m, 0, NULL);
1762         if (r < 0)
1763                 return log_error_errno(r, "Failed to add veth interface to bridge: %m");
1764
1765         return 0;
1766 }
1767
1768 static int parse_interface(struct udev *udev, const char *name) {
1769         _cleanup_udev_device_unref_ struct udev_device *d = NULL;
1770         char ifi_str[2 + DECIMAL_STR_MAX(int)];
1771         int ifi;
1772
1773         ifi = (int) if_nametoindex(name);
1774         if (ifi <= 0)
1775                 return log_error_errno(errno, "Failed to resolve interface %s: %m", name);
1776
1777         sprintf(ifi_str, "n%i", ifi);
1778         d = udev_device_new_from_device_id(udev, ifi_str);
1779         if (!d)
1780                 return log_error_errno(errno, "Failed to get udev device for interface %s: %m", name);
1781
1782         if (udev_device_get_is_initialized(d) <= 0) {
1783                 log_error("Network interface %s is not initialized yet.", name);
1784                 return -EBUSY;
1785         }
1786
1787         return ifi;
1788 }
1789
1790 static int move_network_interfaces(pid_t pid) {
1791         _cleanup_udev_unref_ struct udev *udev = NULL;
1792         _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
1793         char **i;
1794         int r;
1795
1796         if (!arg_private_network)
1797                 return 0;
1798
1799         if (strv_isempty(arg_network_interfaces))
1800                 return 0;
1801
1802         r = sd_rtnl_open(&rtnl, 0);
1803         if (r < 0)
1804                 return log_error_errno(r, "Failed to connect to netlink: %m");
1805
1806         udev = udev_new();
1807         if (!udev) {
1808                 log_error("Failed to connect to udev.");
1809                 return -ENOMEM;
1810         }
1811
1812         STRV_FOREACH(i, arg_network_interfaces) {
1813                 _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
1814                 int ifi;
1815
1816                 ifi = parse_interface(udev, *i);
1817                 if (ifi < 0)
1818                         return ifi;
1819
1820                 r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, ifi);
1821                 if (r < 0)
1822                         return log_error_errno(r, "Failed to allocate netlink message: %m");
1823
1824                 r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid);
1825                 if (r < 0)
1826                         return log_error_errno(r, "Failed to append namespace PID to netlink message: %m");
1827
1828                 r = sd_rtnl_call(rtnl, m, 0, NULL);
1829                 if (r < 0)
1830                         return log_error_errno(r, "Failed to move interface %s to namespace: %m", *i);
1831         }
1832
1833         return 0;
1834 }
1835
1836 static int setup_macvlan(pid_t pid) {
1837         _cleanup_udev_unref_ struct udev *udev = NULL;
1838         _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
1839         char **i;
1840         int r;
1841
1842         if (!arg_private_network)
1843                 return 0;
1844
1845         if (strv_isempty(arg_network_macvlan))
1846                 return 0;
1847
1848         r = sd_rtnl_open(&rtnl, 0);
1849         if (r < 0)
1850                 return log_error_errno(r, "Failed to connect to netlink: %m");
1851
1852         udev = udev_new();
1853         if (!udev) {
1854                 log_error("Failed to connect to udev.");
1855                 return -ENOMEM;
1856         }
1857
1858         STRV_FOREACH(i, arg_network_macvlan) {
1859                 _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
1860                 _cleanup_free_ char *n = NULL;
1861                 int ifi;
1862
1863                 ifi = parse_interface(udev, *i);
1864                 if (ifi < 0)
1865                         return ifi;
1866
1867                 r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
1868                 if (r < 0)
1869                         return log_error_errno(r, "Failed to allocate netlink message: %m");
1870
1871                 r = sd_rtnl_message_append_u32(m, IFLA_LINK, ifi);
1872                 if (r < 0)
1873                         return log_error_errno(r, "Failed to add netlink interface index: %m");
1874
1875                 n = strappend("mv-", *i);
1876                 if (!n)
1877                         return log_oom();
1878
1879                 strshorten(n, IFNAMSIZ-1);
1880
1881                 r = sd_rtnl_message_append_string(m, IFLA_IFNAME, n);
1882                 if (r < 0)
1883                         return log_error_errno(r, "Failed to add netlink interface name: %m");
1884
1885                 r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid);
1886                 if (r < 0)
1887                         return log_error_errno(r, "Failed to add netlink namespace field: %m");
1888
1889                 r = sd_rtnl_message_open_container(m, IFLA_LINKINFO);
1890                 if (r < 0)
1891                         return log_error_errno(r, "Failed to open netlink container: %m");
1892
1893                 r = sd_rtnl_message_open_container_union(m, IFLA_INFO_DATA, "macvlan");
1894                 if (r < 0)
1895                         return log_error_errno(r, "Failed to open netlink container: %m");
1896
1897                 r = sd_rtnl_message_append_u32(m, IFLA_MACVLAN_MODE, MACVLAN_MODE_BRIDGE);
1898                 if (r < 0)
1899                         return log_error_errno(r, "Failed to append macvlan mode: %m");
1900
1901                 r = sd_rtnl_message_close_container(m);
1902                 if (r < 0)
1903                         return log_error_errno(r, "Failed to close netlink container: %m");
1904
1905                 r = sd_rtnl_message_close_container(m);
1906                 if (r < 0)
1907                         return log_error_errno(r, "Failed to close netlink container: %m");
1908
1909                 r = sd_rtnl_call(rtnl, m, 0, NULL);
1910                 if (r < 0)
1911                         return log_error_errno(r, "Failed to add new macvlan interfaces: %m");
1912         }
1913
1914         return 0;
1915 }
1916
1917 static int setup_seccomp(void) {
1918
1919 #ifdef HAVE_SECCOMP
1920         static const int blacklist[] = {
1921                 SCMP_SYS(kexec_load),
1922                 SCMP_SYS(open_by_handle_at),
1923                 SCMP_SYS(init_module),
1924                 SCMP_SYS(finit_module),
1925                 SCMP_SYS(delete_module),
1926                 SCMP_SYS(iopl),
1927                 SCMP_SYS(ioperm),
1928                 SCMP_SYS(swapon),
1929                 SCMP_SYS(swapoff),
1930         };
1931
1932         scmp_filter_ctx seccomp;
1933         unsigned i;
1934         int r;
1935
1936         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1937         if (!seccomp)
1938                 return log_oom();
1939
1940         r = seccomp_add_secondary_archs(seccomp);
1941         if (r < 0) {
1942                 log_error_errno(r, "Failed to add secondary archs to seccomp filter: %m");
1943                 goto finish;
1944         }
1945
1946         for (i = 0; i < ELEMENTSOF(blacklist); i++) {
1947                 r = seccomp_rule_add(seccomp, SCMP_ACT_ERRNO(EPERM), blacklist[i], 0);
1948                 if (r == -EFAULT)
1949                         continue; /* unknown syscall */
1950                 if (r < 0) {
1951                         log_error_errno(r, "Failed to block syscall: %m");
1952                         goto finish;
1953                 }
1954         }
1955
1956         /*
1957            Audit is broken in containers, much of the userspace audit
1958            hookup will fail if running inside a container. We don't
1959            care and just turn off creation of audit sockets.
1960
1961            This will make socket(AF_NETLINK, *, NETLINK_AUDIT) fail
1962            with EAFNOSUPPORT which audit userspace uses as indication
1963            that audit is disabled in the kernel.
1964          */
1965
1966         r = seccomp_rule_add(
1967                         seccomp,
1968                         SCMP_ACT_ERRNO(EAFNOSUPPORT),
1969                         SCMP_SYS(socket),
1970                         2,
1971                         SCMP_A0(SCMP_CMP_EQ, AF_NETLINK),
1972                         SCMP_A2(SCMP_CMP_EQ, NETLINK_AUDIT));
1973         if (r < 0) {
1974                 log_error_errno(r, "Failed to add audit seccomp rule: %m");
1975                 goto finish;
1976         }
1977
1978         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1979         if (r < 0) {
1980                 log_error_errno(r, "Failed to unset NO_NEW_PRIVS: %m");
1981                 goto finish;
1982         }
1983
1984         r = seccomp_load(seccomp);
1985         if (r < 0)
1986                 log_error_errno(r, "Failed to install seccomp audit filter: %m");
1987
1988 finish:
1989         seccomp_release(seccomp);
1990         return r;
1991 #else
1992         return 0;
1993 #endif
1994
1995 }
1996
1997 static int setup_image(char **device_path, int *loop_nr) {
1998         struct loop_info64 info = {
1999                 .lo_flags = LO_FLAGS_AUTOCLEAR|LO_FLAGS_PARTSCAN
2000         };
2001         _cleanup_close_ int fd = -1, control = -1, loop = -1;
2002         _cleanup_free_ char* loopdev = NULL;
2003         struct stat st;
2004         int r, nr;
2005
2006         assert(device_path);
2007         assert(loop_nr);
2008
2009         fd = open(arg_image, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY);
2010         if (fd < 0)
2011                 return log_error_errno(errno, "Failed to open %s: %m", arg_image);
2012
2013         if (fstat(fd, &st) < 0)
2014                 return log_error_errno(errno, "Failed to stat %s: %m", arg_image);
2015
2016         if (S_ISBLK(st.st_mode)) {
2017                 char *p;
2018
2019                 p = strdup(arg_image);
2020                 if (!p)
2021                         return log_oom();
2022
2023                 *device_path = p;
2024
2025                 *loop_nr = -1;
2026
2027                 r = fd;
2028                 fd = -1;
2029
2030                 return r;
2031         }
2032
2033         if (!S_ISREG(st.st_mode)) {
2034                 log_error_errno(errno, "%s is not a regular file or block device: %m", arg_image);
2035                 return -EINVAL;
2036         }
2037
2038         control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
2039         if (control < 0)
2040                 return log_error_errno(errno, "Failed to open /dev/loop-control: %m");
2041
2042         nr = ioctl(control, LOOP_CTL_GET_FREE);
2043         if (nr < 0)
2044                 return log_error_errno(errno, "Failed to allocate loop device: %m");
2045
2046         if (asprintf(&loopdev, "/dev/loop%i", nr) < 0)
2047                 return log_oom();
2048
2049         loop = open(loopdev, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY);
2050         if (loop < 0)
2051                 return log_error_errno(errno, "Failed to open loop device %s: %m", loopdev);
2052
2053         if (ioctl(loop, LOOP_SET_FD, fd) < 0)
2054                 return log_error_errno(errno, "Failed to set loopback file descriptor on %s: %m", loopdev);
2055
2056         if (arg_read_only)
2057                 info.lo_flags |= LO_FLAGS_READ_ONLY;
2058
2059         if (ioctl(loop, LOOP_SET_STATUS64, &info) < 0)
2060                 return log_error_errno(errno, "Failed to set loopback settings on %s: %m", loopdev);
2061
2062         *device_path = loopdev;
2063         loopdev = NULL;
2064
2065         *loop_nr = nr;
2066
2067         r = loop;
2068         loop = -1;
2069
2070         return r;
2071 }
2072
2073 static int dissect_image(
2074                 int fd,
2075                 char **root_device, bool *root_device_rw,
2076                 char **home_device, bool *home_device_rw,
2077                 char **srv_device, bool *srv_device_rw,
2078                 bool *secondary) {
2079
2080 #ifdef HAVE_BLKID
2081         int home_nr = -1, root_nr = -1, secondary_root_nr = -1, srv_nr = -1;
2082         _cleanup_free_ char *home = NULL, *root = NULL, *secondary_root = NULL, *srv = NULL;
2083         _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
2084         _cleanup_udev_device_unref_ struct udev_device *d = NULL;
2085         _cleanup_blkid_free_probe_ blkid_probe b = NULL;
2086         _cleanup_udev_unref_ struct udev *udev = NULL;
2087         struct udev_list_entry *first, *item;
2088         bool home_rw = true, root_rw = true, secondary_root_rw = true, srv_rw = true;
2089         const char *pttype = NULL;
2090         blkid_partlist pl;
2091         struct stat st;
2092         int r;
2093
2094         assert(fd >= 0);
2095         assert(root_device);
2096         assert(home_device);
2097         assert(srv_device);
2098         assert(secondary);
2099
2100         b = blkid_new_probe();
2101         if (!b)
2102                 return log_oom();
2103
2104         errno = 0;
2105         r = blkid_probe_set_device(b, fd, 0, 0);
2106         if (r != 0) {
2107                 if (errno == 0)
2108                         return log_oom();
2109
2110                 log_error_errno(errno, "Failed to set device on blkid probe: %m");
2111                 return -errno;
2112         }
2113
2114         blkid_probe_enable_partitions(b, 1);
2115         blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
2116
2117         errno = 0;
2118         r = blkid_do_safeprobe(b);
2119         if (r == -2 || r == 1) {
2120                 log_error("Failed to identify any partition table on %s.\n"
2121                           "Note that the disk image needs to follow http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/ to be supported by systemd-nspawn.", arg_image);
2122                 return -EINVAL;
2123         } else if (r != 0) {
2124                 if (errno == 0)
2125                         errno = EIO;
2126                 log_error_errno(errno, "Failed to probe: %m");
2127                 return -errno;
2128         }
2129
2130         blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
2131         if (!streq_ptr(pttype, "gpt")) {
2132                 log_error("Image %s does not carry a GUID Partition Table.\n"
2133                           "Note that the disk image needs to follow http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/ to be supported by systemd-nspawn.", arg_image);
2134                 return -EINVAL;
2135         }
2136
2137         errno = 0;
2138         pl = blkid_probe_get_partitions(b);
2139         if (!pl) {
2140                 if (errno == 0)
2141                         return log_oom();
2142
2143                 log_error("Failed to list partitions of %s", arg_image);
2144                 return -errno;
2145         }
2146
2147         udev = udev_new();
2148         if (!udev)
2149                 return log_oom();
2150
2151         if (fstat(fd, &st) < 0)
2152                 return log_error_errno(errno, "Failed to stat block device: %m");
2153
2154         d = udev_device_new_from_devnum(udev, 'b', st.st_rdev);
2155         if (!d)
2156                 return log_oom();
2157
2158         e = udev_enumerate_new(udev);
2159         if (!e)
2160                 return log_oom();
2161
2162         r = udev_enumerate_add_match_parent(e, d);
2163         if (r < 0)
2164                 return log_oom();
2165
2166         r = udev_enumerate_scan_devices(e);
2167         if (r < 0)
2168                 return log_error_errno(r, "Failed to scan for partition devices of %s: %m", arg_image);
2169
2170         first = udev_enumerate_get_list_entry(e);
2171         udev_list_entry_foreach(item, first) {
2172                 _cleanup_udev_device_unref_ struct udev_device *q;
2173                 const char *stype, *node;
2174                 unsigned long long flags;
2175                 sd_id128_t type_id;
2176                 blkid_partition pp;
2177                 dev_t qn;
2178                 int nr;
2179
2180                 errno = 0;
2181                 q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
2182                 if (!q) {
2183                         if (!errno)
2184                                 errno = ENOMEM;
2185
2186                         log_error_errno(errno, "Failed to get partition device of %s: %m", arg_image);
2187                         return -errno;
2188                 }
2189
2190                 qn = udev_device_get_devnum(q);
2191                 if (major(qn) == 0)
2192                         continue;
2193
2194                 if (st.st_rdev == qn)
2195                         continue;
2196
2197                 node = udev_device_get_devnode(q);
2198                 if (!node)
2199                         continue;
2200
2201                 pp = blkid_partlist_devno_to_partition(pl, qn);
2202                 if (!pp)
2203                         continue;
2204
2205                 flags = blkid_partition_get_flags(pp);
2206                 if (flags & GPT_FLAG_NO_AUTO)
2207                         continue;
2208
2209                 nr = blkid_partition_get_partno(pp);
2210                 if (nr < 0)
2211                         continue;
2212
2213                 stype = blkid_partition_get_type_string(pp);
2214                 if (!stype)
2215                         continue;
2216
2217                 if (sd_id128_from_string(stype, &type_id) < 0)
2218                         continue;
2219
2220                 if (sd_id128_equal(type_id, GPT_HOME)) {
2221
2222                         if (home && nr >= home_nr)
2223                                 continue;
2224
2225                         home_nr = nr;
2226                         home_rw = !(flags & GPT_FLAG_READ_ONLY);
2227
2228                         free(home);
2229                         home = strdup(node);
2230                         if (!home)
2231                                 return log_oom();
2232                 } else if (sd_id128_equal(type_id, GPT_SRV)) {
2233
2234                         if (srv && nr >= srv_nr)
2235                                 continue;
2236
2237                         srv_nr = nr;
2238                         srv_rw = !(flags & GPT_FLAG_READ_ONLY);
2239
2240                         free(srv);
2241                         srv = strdup(node);
2242                         if (!srv)
2243                                 return log_oom();
2244                 }
2245 #ifdef GPT_ROOT_NATIVE
2246                 else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) {
2247
2248                         if (root && nr >= root_nr)
2249                                 continue;
2250
2251                         root_nr = nr;
2252                         root_rw = !(flags & GPT_FLAG_READ_ONLY);
2253
2254                         free(root);
2255                         root = strdup(node);
2256                         if (!root)
2257                                 return log_oom();
2258                 }
2259 #endif
2260 #ifdef GPT_ROOT_SECONDARY
2261                 else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY)) {
2262
2263                         if (secondary_root && nr >= secondary_root_nr)
2264                                 continue;
2265
2266                         secondary_root_nr = nr;
2267                         secondary_root_rw = !(flags & GPT_FLAG_READ_ONLY);
2268
2269
2270                         free(secondary_root);
2271                         secondary_root = strdup(node);
2272                         if (!secondary_root)
2273                                 return log_oom();
2274                 }
2275 #endif
2276         }
2277
2278         if (!root && !secondary_root) {
2279                 log_error("Failed to identify root partition in disk image %s.\n"
2280                           "Note that the disk image needs to follow http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/ to be supported by systemd-nspawn.", arg_image);
2281                 return -EINVAL;
2282         }
2283
2284         if (root) {
2285                 *root_device = root;
2286                 root = NULL;
2287
2288                 *root_device_rw = root_rw;
2289                 *secondary = false;
2290         } else if (secondary_root) {
2291                 *root_device = secondary_root;
2292                 secondary_root = NULL;
2293
2294                 *root_device_rw = secondary_root_rw;
2295                 *secondary = true;
2296         }
2297
2298         if (home) {
2299                 *home_device = home;
2300                 home = NULL;
2301
2302                 *home_device_rw = home_rw;
2303         }
2304
2305         if (srv) {
2306                 *srv_device = srv;
2307                 srv = NULL;
2308
2309                 *srv_device_rw = srv_rw;
2310         }
2311
2312         return 0;
2313 #else
2314         log_error("--image= is not supported, compiled without blkid support.");
2315         return -ENOTSUP;
2316 #endif
2317 }
2318
2319 static int mount_device(const char *what, const char *where, const char *directory, bool rw) {
2320 #ifdef HAVE_BLKID
2321         _cleanup_blkid_free_probe_ blkid_probe b = NULL;
2322         const char *fstype, *p;
2323         int r;
2324
2325         assert(what);
2326         assert(where);
2327
2328         if (arg_read_only)
2329                 rw = false;
2330
2331         if (directory)
2332                 p = strappenda(where, directory);
2333         else
2334                 p = where;
2335
2336         errno = 0;
2337         b = blkid_new_probe_from_filename(what);
2338         if (!b) {
2339                 if (errno == 0)
2340                         return log_oom();
2341                 log_error_errno(errno, "Failed to allocate prober for %s: %m", what);
2342                 return -errno;
2343         }
2344
2345         blkid_probe_enable_superblocks(b, 1);
2346         blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
2347
2348         errno = 0;
2349         r = blkid_do_safeprobe(b);
2350         if (r == -1 || r == 1) {
2351                 log_error("Cannot determine file system type of %s", what);
2352                 return -EINVAL;
2353         } else if (r != 0) {
2354                 if (errno == 0)
2355                         errno = EIO;
2356                 log_error_errno(errno, "Failed to probe %s: %m", what);
2357                 return -errno;
2358         }
2359
2360         errno = 0;
2361         if (blkid_probe_lookup_value(b, "TYPE", &fstype, NULL) < 0) {
2362                 if (errno == 0)
2363                         errno = EINVAL;
2364                 log_error("Failed to determine file system type of %s", what);
2365                 return -errno;
2366         }
2367
2368         if (streq(fstype, "crypto_LUKS")) {
2369                 log_error("nspawn currently does not support LUKS disk images.");
2370                 return -ENOTSUP;
2371         }
2372
2373         if (mount(what, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), NULL) < 0)
2374                 return log_error_errno(errno, "Failed to mount %s: %m", what);
2375
2376         return 0;
2377 #else
2378         log_error("--image= is not supported, compiled without blkid support.");
2379         return -ENOTSUP;
2380 #endif
2381 }
2382
2383 static int mount_devices(
2384                 const char *where,
2385                 const char *root_device, bool root_device_rw,
2386                 const char *home_device, bool home_device_rw,
2387                 const char *srv_device, bool srv_device_rw) {
2388         int r;
2389
2390         assert(where);
2391
2392         if (root_device) {
2393                 r = mount_device(root_device, arg_directory, NULL, root_device_rw);
2394                 if (r < 0)
2395                         return log_error_errno(r, "Failed to mount root directory: %m");
2396         }
2397
2398         if (home_device) {
2399                 r = mount_device(home_device, arg_directory, "/home", home_device_rw);
2400                 if (r < 0)
2401                         return log_error_errno(r, "Failed to mount home directory: %m");
2402         }
2403
2404         if (srv_device) {
2405                 r = mount_device(srv_device, arg_directory, "/srv", srv_device_rw);
2406                 if (r < 0)
2407                         return log_error_errno(r, "Failed to mount server data directory: %m");
2408         }
2409
2410         return 0;
2411 }
2412
2413 static void loop_remove(int nr, int *image_fd) {
2414         _cleanup_close_ int control = -1;
2415         int r;
2416
2417         if (nr < 0)
2418                 return;
2419
2420         if (image_fd && *image_fd >= 0) {
2421                 r = ioctl(*image_fd, LOOP_CLR_FD);
2422                 if (r < 0)
2423                         log_warning_errno(errno, "Failed to close loop image: %m");
2424                 *image_fd = safe_close(*image_fd);
2425         }
2426
2427         control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
2428         if (control < 0) {
2429                 log_warning_errno(errno, "Failed to open /dev/loop-control: %m");
2430                 return;
2431         }
2432
2433         r = ioctl(control, LOOP_CTL_REMOVE, nr);
2434         if (r < 0)
2435                 log_warning_errno(errno, "Failed to remove loop %d: %m", nr);
2436 }
2437
2438 static int spawn_getent(const char *database, const char *key, pid_t *rpid) {
2439         int pipe_fds[2];
2440         pid_t pid;
2441
2442         assert(database);
2443         assert(key);
2444         assert(rpid);
2445
2446         if (pipe2(pipe_fds, O_CLOEXEC) < 0)
2447                 return log_error_errno(errno, "Failed to allocate pipe: %m");
2448
2449         pid = fork();
2450         if (pid < 0)
2451                 return log_error_errno(errno, "Failed to fork getent child: %m");
2452         else if (pid == 0) {
2453                 int nullfd;
2454                 char *empty_env = NULL;
2455
2456                 if (dup3(pipe_fds[1], STDOUT_FILENO, 0) < 0)
2457                         _exit(EXIT_FAILURE);
2458
2459                 if (pipe_fds[0] > 2)
2460                         safe_close(pipe_fds[0]);
2461                 if (pipe_fds[1] > 2)
2462                         safe_close(pipe_fds[1]);
2463
2464                 nullfd = open("/dev/null", O_RDWR);
2465                 if (nullfd < 0)
2466                         _exit(EXIT_FAILURE);
2467
2468                 if (dup3(nullfd, STDIN_FILENO, 0) < 0)
2469                         _exit(EXIT_FAILURE);
2470
2471                 if (dup3(nullfd, STDERR_FILENO, 0) < 0)
2472                         _exit(EXIT_FAILURE);
2473
2474                 if (nullfd > 2)
2475                         safe_close(nullfd);
2476
2477                 reset_all_signal_handlers();
2478                 close_all_fds(NULL, 0);
2479
2480                 execle("/usr/bin/getent", "getent", database, key, NULL, &empty_env);
2481                 execle("/bin/getent", "getent", database, key, NULL, &empty_env);
2482                 _exit(EXIT_FAILURE);
2483         }
2484
2485         pipe_fds[1] = safe_close(pipe_fds[1]);
2486
2487         *rpid = pid;
2488
2489         return pipe_fds[0];
2490 }
2491
2492 static int change_uid_gid(char **_home) {
2493         char line[LINE_MAX], *x, *u, *g, *h;
2494         const char *word, *state;
2495         _cleanup_free_ uid_t *uids = NULL;
2496         _cleanup_free_ char *home = NULL;
2497         _cleanup_fclose_ FILE *f = NULL;
2498         _cleanup_close_ int fd = -1;
2499         unsigned n_uids = 0;
2500         size_t sz = 0, l;
2501         uid_t uid;
2502         gid_t gid;
2503         pid_t pid;
2504         int r;
2505
2506         assert(_home);
2507
2508         if (!arg_user || streq(arg_user, "root") || streq(arg_user, "0")) {
2509                 /* Reset everything fully to 0, just in case */
2510
2511                 if (setgroups(0, NULL) < 0)
2512                         return log_error_errno(errno, "setgroups() failed: %m");
2513
2514                 if (setresgid(0, 0, 0) < 0)
2515                         return log_error_errno(errno, "setregid() failed: %m");
2516
2517                 if (setresuid(0, 0, 0) < 0)
2518                         return log_error_errno(errno, "setreuid() failed: %m");
2519
2520                 *_home = NULL;
2521                 return 0;
2522         }
2523
2524         /* First, get user credentials */
2525         fd = spawn_getent("passwd", arg_user, &pid);
2526         if (fd < 0)
2527                 return fd;
2528
2529         f = fdopen(fd, "r");
2530         if (!f)
2531                 return log_oom();
2532         fd = -1;
2533
2534         if (!fgets(line, sizeof(line), f)) {
2535
2536                 if (!ferror(f)) {
2537                         log_error("Failed to resolve user %s.", arg_user);
2538                         return -ESRCH;
2539                 }
2540
2541                 log_error_errno(errno, "Failed to read from getent: %m");
2542                 return -errno;
2543         }
2544
2545         truncate_nl(line);
2546
2547         wait_for_terminate_and_warn("getent passwd", pid, true);
2548
2549         x = strchr(line, ':');
2550         if (!x) {
2551                 log_error("/etc/passwd entry has invalid user field.");
2552                 return -EIO;
2553         }
2554
2555         u = strchr(x+1, ':');
2556         if (!u) {
2557                 log_error("/etc/passwd entry has invalid password field.");
2558                 return -EIO;
2559         }
2560
2561         u++;
2562         g = strchr(u, ':');
2563         if (!g) {
2564                 log_error("/etc/passwd entry has invalid UID field.");
2565                 return -EIO;
2566         }
2567
2568         *g = 0;
2569         g++;
2570         x = strchr(g, ':');
2571         if (!x) {
2572                 log_error("/etc/passwd entry has invalid GID field.");
2573                 return -EIO;
2574         }
2575
2576         *x = 0;
2577         h = strchr(x+1, ':');
2578         if (!h) {
2579                 log_error("/etc/passwd entry has invalid GECOS field.");
2580                 return -EIO;
2581         }
2582
2583         h++;
2584         x = strchr(h, ':');
2585         if (!x) {
2586                 log_error("/etc/passwd entry has invalid home directory field.");
2587                 return -EIO;
2588         }
2589
2590         *x = 0;
2591
2592         r = parse_uid(u, &uid);
2593         if (r < 0) {
2594                 log_error("Failed to parse UID of user.");
2595                 return -EIO;
2596         }
2597
2598         r = parse_gid(g, &gid);
2599         if (r < 0) {
2600                 log_error("Failed to parse GID of user.");
2601                 return -EIO;
2602         }
2603
2604         home = strdup(h);
2605         if (!home)
2606                 return log_oom();
2607
2608         /* Second, get group memberships */
2609         fd = spawn_getent("initgroups", arg_user, &pid);
2610         if (fd < 0)
2611                 return fd;
2612
2613         fclose(f);
2614         f = fdopen(fd, "r");
2615         if (!f)
2616                 return log_oom();
2617         fd = -1;
2618
2619         if (!fgets(line, sizeof(line), f)) {
2620                 if (!ferror(f)) {
2621                         log_error("Failed to resolve user %s.", arg_user);
2622                         return -ESRCH;
2623                 }
2624
2625                 log_error_errno(errno, "Failed to read from getent: %m");
2626                 return -errno;
2627         }
2628
2629         truncate_nl(line);
2630
2631         wait_for_terminate_and_warn("getent initgroups", pid, true);
2632
2633         /* Skip over the username and subsequent separator whitespace */
2634         x = line;
2635         x += strcspn(x, WHITESPACE);
2636         x += strspn(x, WHITESPACE);
2637
2638         FOREACH_WORD(word, l, x, state) {
2639                 char c[l+1];
2640
2641                 memcpy(c, word, l);
2642                 c[l] = 0;
2643
2644                 if (!GREEDY_REALLOC(uids, sz, n_uids+1))
2645                         return log_oom();
2646
2647                 r = parse_uid(c, &uids[n_uids++]);
2648                 if (r < 0) {
2649                         log_error("Failed to parse group data from getent.");
2650                         return -EIO;
2651                 }
2652         }
2653
2654         r = mkdir_parents(home, 0775);
2655         if (r < 0)
2656                 return log_error_errno(r, "Failed to make home root directory: %m");
2657
2658         r = mkdir_safe(home, 0755, uid, gid);
2659         if (r < 0 && r != -EEXIST)
2660                 return log_error_errno(r, "Failed to make home directory: %m");
2661
2662         fchown(STDIN_FILENO, uid, gid);
2663         fchown(STDOUT_FILENO, uid, gid);
2664         fchown(STDERR_FILENO, uid, gid);
2665
2666         if (setgroups(n_uids, uids) < 0)
2667                 return log_error_errno(errno, "Failed to set auxiliary groups: %m");
2668
2669         if (setresgid(gid, gid, gid) < 0)
2670                 return log_error_errno(errno, "setregid() failed: %m");
2671
2672         if (setresuid(uid, uid, uid) < 0)
2673                 return log_error_errno(errno, "setreuid() failed: %m");
2674
2675         if (_home) {
2676                 *_home = home;
2677                 home = NULL;
2678         }
2679
2680         return 0;
2681 }
2682
2683 /*
2684  * Return values:
2685  * < 0 : wait_for_terminate() failed to get the state of the
2686  *       container, the container was terminated by a signal, or
2687  *       failed for an unknown reason.  No change is made to the
2688  *       container argument.
2689  * > 0 : The program executed in the container terminated with an
2690  *       error.  The exit code of the program executed in the
2691  *       container is returned.  The container argument has been set
2692  *       to CONTAINER_TERMINATED.
2693  *   0 : The container is being rebooted, has been shut down or exited
2694  *       successfully.  The container argument has been set to either
2695  *       CONTAINER_TERMINATED or CONTAINER_REBOOTED.
2696  *
2697  * That is, success is indicated by a return value of zero, and an
2698  * error is indicated by a non-zero value.
2699  */
2700 static int wait_for_container(pid_t pid, ContainerStatus *container) {
2701         siginfo_t status;
2702         int r;
2703
2704         r = wait_for_terminate(pid, &status);
2705         if (r < 0)
2706                 return log_warning_errno(r, "Failed to wait for container: %m");
2707
2708         switch (status.si_code) {
2709
2710         case CLD_EXITED:
2711                 if (status.si_status == 0) {
2712                         log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s exited successfully.", arg_machine);
2713
2714                 } else
2715                         log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s failed with error code %i.", arg_machine, status.si_status);
2716
2717                 *container = CONTAINER_TERMINATED;
2718                 return status.si_status;
2719
2720         case CLD_KILLED:
2721                 if (status.si_status == SIGINT) {
2722
2723                         log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s has been shut down.", arg_machine);
2724                         *container = CONTAINER_TERMINATED;
2725                         return 0;
2726
2727                 } else if (status.si_status == SIGHUP) {
2728
2729                         log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s is being rebooted.", arg_machine);
2730                         *container = CONTAINER_REBOOTED;
2731                         return 0;
2732                 }
2733
2734                 /* CLD_KILLED fallthrough */
2735
2736         case CLD_DUMPED:
2737                 log_error("Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status));
2738                 return -EIO;
2739
2740         default:
2741                 log_error("Container %s failed due to unknown reason.", arg_machine);
2742                 return -EIO;
2743         }
2744
2745         return r;
2746 }
2747
2748 static void nop_handler(int sig) {}
2749
2750 static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
2751         pid_t pid;
2752
2753         pid = PTR_TO_UINT32(userdata);
2754         if (pid > 0) {
2755                 if (kill(pid, SIGRTMIN+3) >= 0) {
2756                         log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
2757                         sd_event_source_set_userdata(s, NULL);
2758                         return 0;
2759                 }
2760         }
2761
2762         sd_event_exit(sd_event_source_get_event(s), 0);
2763         return 0;
2764 }
2765
2766 int main(int argc, char *argv[]) {
2767
2768         _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_device = NULL;
2769         bool root_device_rw = true, home_device_rw = true, srv_device_rw = true;
2770         _cleanup_close_ int master = -1, image_fd = -1;
2771         _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 };
2772         _cleanup_fdset_free_ FDSet *fds = NULL;
2773         int r = EXIT_FAILURE, k, n_fd_passed, loop_nr = -1;
2774         const char *console = NULL;
2775         char veth_name[IFNAMSIZ];
2776         bool secondary = false;
2777         sigset_t mask, mask_chld;
2778         pid_t pid = 0;
2779
2780         log_parse_environment();
2781         log_open();
2782
2783         k = parse_argv(argc, argv);
2784         if (k < 0)
2785                 goto finish;
2786         else if (k == 0) {
2787                 r = EXIT_SUCCESS;
2788                 goto finish;
2789         }
2790
2791         if (!arg_image) {
2792                 if (arg_directory) {
2793                         char *p;
2794
2795                         p = path_make_absolute_cwd(arg_directory);
2796                         free(arg_directory);
2797                         arg_directory = p;
2798                 } else
2799                         arg_directory = get_current_dir_name();
2800
2801                 if (!arg_directory) {
2802                         log_error("Failed to determine path, please use -D.");
2803                         goto finish;
2804                 }
2805                 path_kill_slashes(arg_directory);
2806         }
2807
2808         if (!arg_machine) {
2809                 arg_machine = strdup(basename(arg_image ? arg_image : arg_directory));
2810                 if (!arg_machine) {
2811                         log_oom();
2812                         goto finish;
2813                 }
2814
2815                 hostname_cleanup(arg_machine, false);
2816                 if (isempty(arg_machine)) {
2817                         log_error("Failed to determine machine name automatically, please use -M.");
2818                         goto finish;
2819                 }
2820         }
2821
2822         if (geteuid() != 0) {
2823                 log_error("Need to be root.");
2824                 goto finish;
2825         }
2826
2827         if (sd_booted() <= 0) {
2828                 log_error("Not running on a systemd system.");
2829                 goto finish;
2830         }
2831
2832         log_close();
2833         n_fd_passed = sd_listen_fds(false);
2834         if (n_fd_passed > 0) {
2835                 k = fdset_new_listen_fds(&fds, false);
2836                 if (k < 0) {
2837                         log_error_errno(k, "Failed to collect file descriptors: %m");
2838                         goto finish;
2839                 }
2840         }
2841         fdset_close_others(fds);
2842         log_open();
2843
2844         if (arg_directory) {
2845                 if (path_equal(arg_directory, "/")) {
2846                         log_error("Spawning container on root directory not supported.");
2847                         goto finish;
2848                 }
2849
2850                 if (arg_boot) {
2851                         if (path_is_os_tree(arg_directory) <= 0) {
2852                                 log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", arg_directory);
2853                                 goto finish;
2854                         }
2855                 } else {
2856                         const char *p;
2857
2858                         p = strappenda(arg_directory,
2859                                        argc > optind && path_is_absolute(argv[optind]) ? argv[optind] : "/usr/bin/");
2860                         if (access(p, F_OK) < 0) {
2861                                 log_error("Directory %s lacks the binary to execute or doesn't look like a binary tree. Refusing.", arg_directory);
2862                                 goto finish;
2863
2864                         }
2865                 }
2866         } else {
2867                 char template[] = "/tmp/nspawn-root-XXXXXX";
2868
2869                 if (!mkdtemp(template)) {
2870                         log_error_errno(errno, "Failed to create temporary directory: %m");
2871                         r = -errno;
2872                         goto finish;
2873                 }
2874
2875                 arg_directory = strdup(template);
2876                 if (!arg_directory) {
2877                         r = log_oom();
2878                         goto finish;
2879                 }
2880
2881                 image_fd = setup_image(&device_path, &loop_nr);
2882                 if (image_fd < 0) {
2883                         r = image_fd;
2884                         goto finish;
2885                 }
2886
2887                 r = dissect_image(image_fd,
2888                                   &root_device, &root_device_rw,
2889                                   &home_device, &home_device_rw,
2890                                   &srv_device, &srv_device_rw,
2891                                   &secondary);
2892                 if (r < 0)
2893                         goto finish;
2894         }
2895
2896         master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
2897         if (master < 0) {
2898                 log_error_errno(errno, "Failed to acquire pseudo tty: %m");
2899                 goto finish;
2900         }
2901
2902         console = ptsname(master);
2903         if (!console) {
2904                 log_error_errno(errno, "Failed to determine tty name: %m");
2905                 goto finish;
2906         }
2907
2908         if (!arg_quiet)
2909                 log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",
2910                          arg_machine, arg_image ? arg_image : arg_directory);
2911
2912         if (unlockpt(master) < 0) {
2913                 log_error_errno(errno, "Failed to unlock tty: %m");
2914                 goto finish;
2915         }
2916
2917         if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
2918                 log_error_errno(errno, "Failed to create kmsg socket pair: %m");
2919                 goto finish;
2920         }
2921
2922         sd_notify(false,
2923                   "READY=1\n"
2924                   "STATUS=Container running.");
2925
2926         assert_se(sigemptyset(&mask) == 0);
2927         sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
2928         assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
2929
2930         assert_se(sigemptyset(&mask_chld) == 0);
2931         assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
2932
2933         for (;;) {
2934                 ContainerStatus container_status;
2935                 _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
2936                 struct sigaction sa = {
2937                         .sa_handler = nop_handler,
2938                         .sa_flags = SA_NOCLDSTOP,
2939                 };
2940
2941                 r = barrier_create(&barrier);
2942                 if (r < 0) {
2943                         log_error_errno(r, "Cannot initialize IPC barrier: %m");
2944                         goto finish;
2945                 }
2946
2947                 /* Child can be killed before execv(), so handle SIGCHLD
2948                  * in order to interrupt parent's blocking calls and
2949                  * give it a chance to call wait() and terminate. */
2950                 r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL);
2951                 if (r < 0) {
2952                         log_error_errno(errno, "Failed to change the signal mask: %m");
2953                         goto finish;
2954                 }
2955
2956                 r = sigaction(SIGCHLD, &sa, NULL);
2957                 if (r < 0) {
2958                         log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
2959                         goto finish;
2960                 }
2961
2962                 pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWNS|
2963                                           (arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS)|
2964                                           (arg_private_network ? CLONE_NEWNET : 0), NULL);
2965                 if (pid < 0) {
2966                         if (errno == EINVAL)
2967                                 log_error_errno(errno, "clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
2968                         else
2969                                 log_error_errno(errno, "clone() failed: %m");
2970
2971                         r = pid;
2972                         goto finish;
2973                 }
2974
2975                 if (pid == 0) {
2976                         /* child */
2977                         _cleanup_free_ char *home = NULL;
2978                         unsigned n_env = 2;
2979                         const char *envp[] = {
2980                                 "PATH=" DEFAULT_PATH_SPLIT_USR,
2981                                 "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
2982                                 NULL, /* TERM */
2983                                 NULL, /* HOME */
2984                                 NULL, /* USER */
2985                                 NULL, /* LOGNAME */
2986                                 NULL, /* container_uuid */
2987                                 NULL, /* LISTEN_FDS */
2988                                 NULL, /* LISTEN_PID */
2989                                 NULL
2990                         };
2991                         char **env_use;
2992
2993                         barrier_set_role(&barrier, BARRIER_CHILD);
2994
2995                         envp[n_env] = strv_find_prefix(environ, "TERM=");
2996                         if (envp[n_env])
2997                                 n_env ++;
2998
2999                         master = safe_close(master);
3000
3001                         close_nointr(STDIN_FILENO);
3002                         close_nointr(STDOUT_FILENO);
3003                         close_nointr(STDERR_FILENO);
3004
3005                         kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
3006
3007                         reset_all_signal_handlers();
3008                         reset_signal_mask();
3009
3010                         k = open_terminal(console, O_RDWR);
3011                         if (k != STDIN_FILENO) {
3012                                 if (k >= 0) {
3013                                         safe_close(k);
3014                                         k = -EINVAL;
3015                                 }
3016
3017                                 log_error_errno(k, "Failed to open console: %m");
3018                                 _exit(EXIT_FAILURE);
3019                         }
3020
3021                         if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
3022                             dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) {
3023                                 log_error_errno(errno, "Failed to duplicate console: %m");
3024                                 _exit(EXIT_FAILURE);
3025                         }
3026
3027                         if (setsid() < 0) {
3028                                 log_error_errno(errno, "setsid() failed: %m");
3029                                 _exit(EXIT_FAILURE);
3030                         }
3031
3032                         if (reset_audit_loginuid() < 0)
3033                                 _exit(EXIT_FAILURE);
3034
3035                         if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
3036                                 log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m");
3037                                 _exit(EXIT_FAILURE);
3038                         }
3039
3040                         /* Mark everything as slave, so that we still
3041                          * receive mounts from the real root, but don't
3042                          * propagate mounts to the real root. */
3043                         if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
3044                                 log_error_errno(errno, "MS_SLAVE|MS_REC failed: %m");
3045                                 _exit(EXIT_FAILURE);
3046                         }
3047
3048                         if (mount_devices(arg_directory,
3049                                           root_device, root_device_rw,
3050                                           home_device, home_device_rw,
3051                                           srv_device, srv_device_rw) < 0)
3052                                 _exit(EXIT_FAILURE);
3053
3054                         /* Turn directory into bind mount */
3055                         if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
3056                                 log_error_errno(errno, "Failed to make bind mount: %m");
3057                                 _exit(EXIT_FAILURE);
3058                         }
3059
3060                         r = setup_volatile(arg_directory);
3061                         if (r < 0)
3062                                 _exit(EXIT_FAILURE);
3063
3064                         if (setup_volatile_state(arg_directory) < 0)
3065                                 _exit(EXIT_FAILURE);
3066
3067                         r = base_filesystem_create(arg_directory);
3068                         if (r < 0)
3069                                 _exit(EXIT_FAILURE);
3070
3071                         if (arg_read_only) {
3072                                 k = bind_remount_recursive(arg_directory, true);
3073                                 if (k < 0) {
3074                                         log_error_errno(k, "Failed to make tree read-only: %m");
3075                                         _exit(EXIT_FAILURE);
3076                                 }
3077                         }
3078
3079                         if (mount_all(arg_directory) < 0)
3080                                 _exit(EXIT_FAILURE);
3081
3082                         if (copy_devnodes(arg_directory) < 0)
3083                                 _exit(EXIT_FAILURE);
3084
3085                         if (setup_ptmx(arg_directory) < 0)
3086                                 _exit(EXIT_FAILURE);
3087
3088                         dev_setup(arg_directory);
3089
3090                         if (setup_seccomp() < 0)
3091                                 _exit(EXIT_FAILURE);
3092
3093                         if (setup_dev_console(arg_directory, console) < 0)
3094                                 _exit(EXIT_FAILURE);
3095
3096                         if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
3097                                 _exit(EXIT_FAILURE);
3098
3099                         kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
3100
3101                         if (setup_boot_id(arg_directory) < 0)
3102                                 _exit(EXIT_FAILURE);
3103
3104                         if (setup_timezone(arg_directory) < 0)
3105                                 _exit(EXIT_FAILURE);