chiark / gitweb /
unit: printf specifiers %u and %h: $USER and $HOME.
[elogind.git] / src / nspawn / nspawn.c
index 7050c05ec2be3e059a9b8da3f29945443744b26c..ffd8fd4ef50a74ac22ebb8fb6c590f1abd09ea85 100644 (file)
 #include "missing.h"
 #include "cgroup-util.h"
 #include "strv.h"
+#include "path-util.h"
 #include "loopback-setup.h"
 
 static char *arg_directory = NULL;
 static char *arg_user = NULL;
 static char **arg_controllers = NULL;
+static char *arg_uuid = NULL;
 static bool arg_private_network = false;
+static bool arg_read_only = false;
 static bool arg_boot = false;
+static uint64_t arg_retain =
+        (1ULL << CAP_CHOWN) |
+        (1ULL << CAP_DAC_OVERRIDE) |
+        (1ULL << CAP_DAC_READ_SEARCH) |
+        (1ULL << CAP_FOWNER) |
+        (1ULL << CAP_FSETID) |
+        (1ULL << CAP_IPC_OWNER) |
+        (1ULL << CAP_KILL) |
+        (1ULL << CAP_LEASE) |
+        (1ULL << CAP_LINUX_IMMUTABLE) |
+        (1ULL << CAP_NET_BIND_SERVICE) |
+        (1ULL << CAP_NET_BROADCAST) |
+        (1ULL << CAP_NET_RAW) |
+        (1ULL << CAP_SETGID) |
+        (1ULL << CAP_SETFCAP) |
+        (1ULL << CAP_SETPCAP) |
+        (1ULL << CAP_SETUID) |
+        (1ULL << CAP_SYS_ADMIN) |
+        (1ULL << CAP_SYS_CHROOT) |
+        (1ULL << CAP_SYS_NICE) |
+        (1ULL << CAP_SYS_PTRACE) |
+        (1ULL << CAP_SYS_TTY_CONFIG) |
+        (1ULL << CAP_SYS_RESOURCE);
 
 static int help(void) {
 
@@ -67,7 +93,10 @@ static int help(void) {
                "  -b --boot             Boot up full system (i.e. invoke init)\n"
                "  -u --user=USER        Run the command under specified user or uid\n"
                "  -C --controllers=LIST Put the container in specified comma-separated cgroup hierarchies\n"
-               "     --private-network  Disable network in container\n",
+               "     --uuid=UUID        Set a specific machine UUID for the container\n"
+               "     --private-network  Disable network in container\n"
+               "     --read-only        Mount the root directory read-only\n"
+               "     --capability=CAP   In addition to the default, retain specified capability\n",
                program_invocation_short_name);
 
         return 0;
@@ -76,7 +105,10 @@ static int help(void) {
 static int parse_argv(int argc, char *argv[]) {
 
         enum {
-                ARG_PRIVATE_NETWORK = 0x100
+                ARG_PRIVATE_NETWORK = 0x100,
+                ARG_UUID,
+                ARG_READ_ONLY,
+                ARG_CAPABILITY
         };
 
         static const struct option options[] = {
@@ -86,6 +118,9 @@ static int parse_argv(int argc, char *argv[]) {
                 { "controllers",     required_argument, NULL, 'C'                 },
                 { "private-network", no_argument,       NULL, ARG_PRIVATE_NETWORK },
                 { "boot",            no_argument,       NULL, 'b'                 },
+                { "uuid",            required_argument, NULL, ARG_UUID            },
+                { "read-only",       no_argument,       NULL, ARG_READ_ONLY       },
+                { "capability",      required_argument, NULL, ARG_CAPABILITY      },
                 { NULL,              0,                 NULL, 0                   }
         };
 
@@ -140,6 +175,41 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_boot = true;
                         break;
 
+                case ARG_UUID:
+                        arg_uuid = optarg;
+                        break;
+
+                case ARG_READ_ONLY:
+                        arg_read_only = true;
+                        break;
+
+                case ARG_CAPABILITY: {
+                        char *state, *word;
+                        size_t length;
+
+                        FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
+                                cap_value_t cap;
+                                char *t;
+
+                                t = strndup(word, length);
+                                if (!t) {
+                                        log_error("Out of memory.");
+                                        return -ENOMEM;
+                                }
+
+                                if (cap_from_name(t, &cap) < 0) {
+                                        log_error("Failed to parse capability %s.", t);
+                                        free(t);
+                                        return -EINVAL;
+                                }
+
+                                free(t);
+                                arg_retain |= 1ULL << (uint64_t) cap;
+                        }
+
+                        break;
+                }
+
                 case '?':
                         return -EINVAL;
 
@@ -205,7 +275,7 @@ static int mount_all(const char *dest) {
                         continue;
                 }
 
-                mkdir_p(where, 0755);
+                mkdir_p_label(where, 0755);
 
                 if (mount(mount_table[k].what,
                           where,
@@ -255,6 +325,28 @@ static int setup_timezone(const char *dest) {
         return 0;
 }
 
+static int setup_resolv_conf(const char *dest) {
+        char *where;
+
+        assert(dest);
+
+        if (arg_private_network)
+                return 0;
+
+        /* Fix resolv.conf, if possible */
+        if (asprintf(&where, "%s/etc/resolv.conf", dest) < 0) {
+                log_error("Out of memory");
+                return -ENOMEM;
+        }
+
+        if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0)
+                mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+
+        free(where);
+
+        return 0;
+}
+
 static int copy_devnodes(const char *dest) {
 
         static const char devnodes[] =
@@ -486,7 +578,7 @@ static int setup_hostname(void) {
         char *hn;
         int r = 0;
 
-        hn = file_name_from_path(arg_directory);
+        hn = path_get_file_name(arg_directory);
         if (hn) {
                 hn = strdup(hn);
                 if (!hn)
@@ -505,49 +597,7 @@ static int setup_hostname(void) {
 }
 
 static int drop_capabilities(void) {
-        static const unsigned long retain[] = {
-                CAP_CHOWN,
-                CAP_DAC_OVERRIDE,
-                CAP_DAC_READ_SEARCH,
-                CAP_FOWNER,
-                CAP_FSETID,
-                CAP_IPC_OWNER,
-                CAP_KILL,
-                CAP_LEASE,
-                CAP_LINUX_IMMUTABLE,
-                CAP_NET_BIND_SERVICE,
-                CAP_NET_BROADCAST,
-                CAP_NET_RAW,
-                CAP_SETGID,
-                CAP_SETFCAP,
-                CAP_SETPCAP,
-                CAP_SETUID,
-                CAP_SYS_ADMIN,
-                CAP_SYS_CHROOT,
-                CAP_SYS_NICE,
-                CAP_SYS_PTRACE,
-                CAP_SYS_TTY_CONFIG
-        };
-
-        unsigned long l;
-
-        for (l = 0; l <= cap_last_cap(); l++) {
-                unsigned i;
-
-                for (i = 0; i < ELEMENTSOF(retain); i++)
-                        if (retain[i] == l)
-                                break;
-
-                if (i < ELEMENTSOF(retain))
-                        continue;
-
-                if (prctl(PR_CAPBSET_DROP, l) < 0) {
-                        log_error("PR_CAPBSET_DROP failed: %m");
-                        return -errno;
-                }
-        }
-
-        return 0;
+        return capability_bounding_set_drop(~arg_retain, false);
 }
 
 static int is_os_tree(const char *path) {
@@ -912,6 +962,7 @@ int main(int argc, char *argv[]) {
                         NULL, /* HOME */
                         NULL, /* USER */
                         NULL, /* LOGNAME */
+                        NULL, /* container_uuid */
                         NULL
                 };
 
@@ -940,6 +991,18 @@ int main(int argc, char *argv[]) {
                 if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) < 0)
                         goto child_fail;
 
+                /* Turn directory into bind mount */
+                if (mount(arg_directory, arg_directory, "bind", MS_BIND, NULL) < 0) {
+                        log_error("Failed to make bind mount.");
+                        goto child_fail;
+                }
+
+                if (arg_read_only)
+                        if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0) {
+                                log_error("Failed to make read-only.");
+                                goto child_fail;
+                        }
+
                 if (mount_all(arg_directory) < 0)
                         goto child_fail;
 
@@ -957,6 +1020,9 @@ int main(int argc, char *argv[]) {
                 if (setup_timezone(arg_directory) < 0)
                         goto child_fail;
 
+                if (setup_resolv_conf(arg_directory) < 0)
+                        goto child_fail;
+
                 if (chdir(arg_directory) < 0) {
                         log_error("chdir(%s) failed: %m", arg_directory);
                         goto child_fail;
@@ -967,8 +1033,8 @@ int main(int argc, char *argv[]) {
                     dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO)
                         goto child_fail;
 
-                if (mount(arg_directory, "/", "bind", MS_BIND, NULL) < 0) {
-                        log_error("mount(MS_MOVE) failed: %m");
+                if (mount(arg_directory, "/", "bind", MS_MOVE, NULL) < 0) {
+                        log_error("mount(MS_BIND) failed: %m");
                         goto child_fail;
                 }
 
@@ -986,8 +1052,10 @@ int main(int argc, char *argv[]) {
 
                 loopback_setup();
 
-                if (drop_capabilities() < 0)
+                if (drop_capabilities() < 0) {
+                        log_error("drop_capabilities() failed: %m");
                         goto child_fail;
+                }
 
                 if (arg_user) {
 
@@ -996,13 +1064,13 @@ int main(int argc, char *argv[]) {
                                 goto child_fail;
                         }
 
-                        if (mkdir_parents(home, 0775) < 0) {
-                                log_error("mkdir_parents() failed: %m");
+                        if (mkdir_parents_label(home, 0775) < 0) {
+                                log_error("mkdir_parents_label() failed: %m");
                                 goto child_fail;
                         }
 
-                        if (safe_mkdir(home, 0775, uid, gid) < 0) {
-                                log_error("safe_mkdir() failed: %m");
+                        if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
+                                log_error("mkdir_safe_label() failed: %m");
                                 goto child_fail;
                         }
 
@@ -1022,13 +1090,20 @@ int main(int argc, char *argv[]) {
                         }
                 }
 
-                if ((asprintf((char**)(envp + 3), "HOME=%s", home? home: "/root") < 0) ||
-                    (asprintf((char**)(envp + 4), "USER=%s", arg_user? arg_user : "root") < 0) ||
-                    (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user? arg_user : "root") < 0)) {
+                if ((asprintf((char**)(envp + 3), "HOME=%s", home ? home: "/root") < 0) ||
+                    (asprintf((char**)(envp + 4), "USER=%s", arg_user ? arg_user : "root") < 0) ||
+                    (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
                     log_error("Out of memory");
                     goto child_fail;
                 }
 
+                if (arg_uuid) {
+                        if (asprintf((char**)(envp + 6), "container_uuid=%s", arg_uuid) < 0) {
+                                log_error("Out of memory");
+                                goto child_fail;
+                        }
+                }
+
                 setup_hostname();
 
                 if (arg_boot) {