chiark / gitweb /
nspawn: bind mount /dev/nul to /proc/kmsg, so that the container can't muck with...
[elogind.git] / src / nspawn.c
index b548b126c6e5dccae2a71abcfdc07a5659d64135..685b4d4e50d4b5c588ebd8374d028b2cb83b046b 100644 (file)
@@ -6,16 +6,16 @@
   Copyright 2010 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.
 
   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  General Public License for more details.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
@@ -43,6 +43,8 @@
 
 #include "log.h"
 #include "util.h"
+#include "mkdir.h"
+#include "audit.h"
 #include "missing.h"
 #include "cgroup-util.h"
 #include "strv.h"
 
 static char *arg_directory = NULL;
 static char *arg_user = NULL;
+static char **arg_controllers = NULL;
 static bool arg_private_network = false;
 
 static int help(void) {
 
         printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
                "Spawn a minimal namespace container for debugging, testing and building.\n\n"
-               "  -h --help            Show this help\n"
-               "  -D --directory=NAME  Root directory for the container\n"
-               "  -u --user=USER       Run the command under specified user or uid\n"
-               "     --private-network Disable network in container\n",
+               "  -h --help             Show this help\n"
+               "  -D --directory=NAME   Root directory for the container\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",
                program_invocation_short_name);
 
         return 0;
@@ -75,6 +79,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "help",            no_argument,       NULL, 'h'                 },
                 { "directory",       required_argument, NULL, 'D'                 },
                 { "user",            required_argument, NULL, 'u'                 },
+                { "controllers",     required_argument, NULL, 'C'                 },
                 { "private-network", no_argument,       NULL, ARG_PRIVATE_NETWORK },
                 { NULL,              0,                 NULL, 0                   }
         };
@@ -84,7 +89,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 0);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "+hD:u:", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "+hD:u:C:", options, NULL)) >= 0) {
 
                 switch (c) {
 
@@ -110,6 +115,17 @@ static int parse_argv(int argc, char *argv[]) {
 
                         break;
 
+                case 'C':
+                        strv_free(arg_controllers);
+                        arg_controllers = strv_split(optarg, ",");
+                        if (!arg_controllers) {
+                                log_error("Failed to split controllers list.");
+                                return -ENOMEM;
+                        }
+                        strv_uniq(arg_controllers);
+
+                        break;
+
                 case ARG_PRIVATE_NETWORK:
                         arg_private_network = true;
                         break;
@@ -143,9 +159,9 @@ static int mount_all(const char *dest) {
                 { "/proc/sys", "/proc/sys", "bind",  NULL,       MS_BIND|MS_RDONLY|MS_REMOUNT, true  },   /* Then, make it r/o */
                 { "/sys",      "/sys",      "bind",  NULL,       MS_BIND,                      true  },   /* Bind mount first */
                 { "/sys",      "/sys",      "bind",  NULL,       MS_BIND|MS_RDONLY|MS_REMOUNT, true  },   /* Then, make it r/o */
-                { "tmpfs",     "/dev",      "tmpfs", "mode=755", MS_NOSUID,                    true  },
+                { "tmpfs",     "/dev",      "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME,     true  },
                 { "/dev/pts",  "/dev/pts",  "bind",  NULL,       MS_BIND,                      true  },
-                { "tmpfs",     "/run",      "tmpfs", "mode=755", MS_NOSUID|MS_NODEV,           true  },
+                { "tmpfs",     "/run",      "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true  },
 #ifdef HAVE_SELINUX
                 { "/sys/fs/selinux", "/sys/fs/selinux", "bind", NULL, MS_BIND,                      false },  /* Bind mount first */
                 { "/sys/fs/selinux", "/sys/fs/selinux", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false },  /* Then, make it r/o */
@@ -168,7 +184,8 @@ static int mount_all(const char *dest) {
                         break;
                 }
 
-                if ((t = path_is_mount_point(where, false)) < 0) {
+                t = path_is_mount_point(where, false);
+                if (t < 0) {
                         log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
                         free(where);
 
@@ -197,7 +214,7 @@ static int mount_all(const char *dest) {
         }
 
         /* Fix the timezone, if possible */
-        if (asprintf(&where, "%s/%s", dest, "/etc/localtime") >= 0) {
+        if (asprintf(&where, "%s/etc/localtime", dest) >= 0) {
 
                 if (mount("/etc/localtime", where, "bind", MS_BIND, NULL) >= 0)
                         mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
@@ -205,6 +222,19 @@ static int mount_all(const char *dest) {
                 free(where);
         }
 
+        if (asprintf(&where, "%s/etc/timezone", dest) >= 0) {
+
+                if (mount("/etc/timezone", where, "bind", MS_BIND, NULL) >= 0)
+                        mount("/etc/timezone", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+
+                free(where);
+        }
+
+        if (asprintf(&where, "%s/proc/kmsg", dest) >= 0) {
+                mount("/dev/null", where, "bind", MS_BIND, NULL);
+                free(where);
+        }
+
         return r;
 }
 
@@ -602,6 +632,7 @@ int main(int argc, char *argv[]) {
         pid_t pid = 0;
         int r = EXIT_FAILURE, k;
         char *oldcg = NULL, *newcg = NULL;
+        char **controller = NULL;
         int master = -1;
         const char *console = NULL;
         struct termios saved_attr, raw_attr;
@@ -661,11 +692,18 @@ int main(int argc, char *argv[]) {
                 goto finish;
         }
 
-        if ((k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0)) < 0)  {
+        k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0);
+        if (k < 0)  {
                 log_error("Failed to create cgroup: %s", strerror(-k));
                 goto finish;
         }
 
+        STRV_FOREACH(controller,arg_controllers) {
+                k = cg_create_and_attach(*controller, newcg, 0);
+                if (k < 0)
+                        log_warning("Failed to create cgroup in controller %s: %s", *controller, strerror(-k));
+        }
+
         if ((master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY)) < 0) {
                 log_error("Failed to acquire pseudo tty: %m");
                 goto finish;
@@ -879,6 +917,7 @@ finish:
                 cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, newcg, true);
 
         free(arg_directory);
+        strv_free(arg_controllers);
         free(oldcg);
         free(newcg);