chiark / gitweb /
execute: make setup_pam() return -errno when possible
[elogind.git] / src / nspawn.c
index 50d7c2e2895717a6ae8a81d19efa8410a31f2a7e..653d7db730a80361b08a2b002415c0cb2e6fcaa6 100644 (file)
@@ -37,6 +37,7 @@
 #include <termios.h>
 #include <sys/signalfd.h>
 #include <grp.h>
+#include <linux/fs.h>
 
 #include "log.h"
 #include "util.h"
 #include "cgroup-util.h"
 #include "sd-daemon.h"
 #include "strv.h"
+#include "loopback-setup.h"
 
 static char *arg_directory = NULL;
 static char *arg_user = NULL;
+static bool arg_private_network = false;
 
 static int help(void) {
 
@@ -54,7 +57,8 @@ static int help(void) {
                "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",
+               "  -u --user=USER       Run the command under specified user or uid\n"
+               "     --private-network Disable network in container\n",
                program_invocation_short_name);
 
         return 0;
@@ -62,11 +66,16 @@ static int help(void) {
 
 static int parse_argv(int argc, char *argv[]) {
 
+        enum {
+                ARG_PRIVATE_NETWORK = 0x100
+        };
+
         static const struct option options[] = {
-                { "help",      no_argument,       NULL, 'h' },
-                { "directory", required_argument, NULL, 'D' },
-                { "user",      optional_argument, NULL, 'u' },
-                { NULL,        0,                 NULL, 0   }
+                { "help",            no_argument,       NULL, 'h'                 },
+                { "directory",       required_argument, NULL, 'D'                 },
+                { "user",            required_argument, NULL, 'u'                 },
+                { "private-network", no_argument,       NULL, ARG_PRIVATE_NETWORK },
+                { NULL,              0,                 NULL, 0                   }
         };
 
         int c;
@@ -100,6 +109,10 @@ static int parse_argv(int argc, char *argv[]) {
 
                         break;
 
+                case ARG_PRIVATE_NETWORK:
+                        arg_private_network = true;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
@@ -124,15 +137,17 @@ static int mount_all(const char *dest) {
         } MountPoint;
 
         static const MountPoint mount_table[] = {
-                { "proc",      "/proc",     "proc",      NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
-                { "/proc/sys", "/proc/sys", "bind",      NULL,        MS_BIND, true },                      /* Bind mount first */
-                { "/proc/sys", "/proc/sys", "bind",      NULL,        MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
-                { "sysfs",     "/sys",      "sysfs",     NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, true },
-                { "tmpfs",     "/dev",      "tmpfs",     "mode=755",  MS_NOSUID, true },
-                { "/dev/pts",  "/dev/pts",  "bind",      NULL,        MS_BIND, true },
-                { "tmpfs",     "/run",      "tmpfs",     "mode=755",  MS_NOSUID|MS_NODEV, true },
+                { "proc",      "/proc",     "proc",  NULL,       MS_NOSUID|MS_NOEXEC|MS_NODEV, true  },
+                { "/proc/sys", "/proc/sys", "bind",  NULL,       MS_BIND, true                       },   /* Bind mount first */
+                { "/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  },
+                { "/dev/pts",  "/dev/pts",  "bind",  NULL,       MS_BIND,                      true  },
+                { "tmpfs",     "/run",      "tmpfs", "mode=755", MS_NOSUID|MS_NODEV,           true  },
 #ifdef HAVE_SELINUX
-                { "selinux",   "/selinux",  "selinuxfs", NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, false },
+                { "/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 */
 #endif
         };
 
@@ -152,7 +167,7 @@ static int mount_all(const char *dest) {
                         break;
                 }
 
-                if ((t = path_is_mount_point(where)) < 0) {
+                if ((t = path_is_mount_point(where, false)) < 0) {
                         log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
                         free(where);
 
@@ -182,8 +197,10 @@ static int mount_all(const char *dest) {
 
         /* Fix the timezone, if possible */
         if (asprintf(&where, "%s/%s", dest, "/etc/localtime") >= 0) {
-                mount("/etc/localtime", where, "bind", MS_BIND, NULL);
-                mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+
+                if (mount("/etc/localtime", where, "bind", MS_BIND, NULL) >= 0)
+                        mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+
                 free(where);
         }
 
@@ -312,7 +329,6 @@ static int copy_devnodes(const char *dest, const char *console) {
         }
 
 finish:
-
         umask(u);
 
         return r;
@@ -345,7 +361,7 @@ static int drop_capabilities(void) {
 
         unsigned long l;
 
-        for (l = 0; l <= MAX(63LU, (unsigned long) CAP_LAST_CAP); l++) {
+        for (l = 0; l <= cap_last_cap(); l++) {
                 unsigned i;
 
                 for (i = 0; i < ELEMENTSOF(retain); i++)
@@ -356,12 +372,6 @@ static int drop_capabilities(void) {
                         continue;
 
                 if (prctl(PR_CAPBSET_DROP, l) < 0) {
-
-                        /* If this capability is not known, EINVAL
-                         * will be returned, let's ignore this. */
-                        if (errno == EINVAL)
-                                break;
-
                         log_error("PR_CAPBSET_DROP failed: %m");
                         return -errno;
                 }
@@ -697,7 +707,7 @@ int main(int argc, char *argv[]) {
         sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
         assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
 
-        if ((pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS, NULL)) < 0) {
+        if ((pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL)) < 0) {
                 log_error("clone() failed: %m");
                 goto finish;
         }
@@ -711,6 +721,7 @@ int main(int argc, char *argv[]) {
                 gid_t gid = (gid_t) -1;
                 const char *envp[] = {
                         "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+                        "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
                         NULL, /* TERM */
                         NULL, /* HOME */
                         NULL, /* USER */
@@ -718,7 +729,7 @@ int main(int argc, char *argv[]) {
                         NULL
                 };
 
-                envp[1] = strv_find_prefix(environ, "TERM=");
+                envp[2] = strv_find_prefix(environ, "TERM=");
 
                 close_nointr_nofail(master);
 
@@ -739,6 +750,10 @@ int main(int argc, char *argv[]) {
                 if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
                         goto child_fail;
 
+                /* Mark / as private, in case somebody marked it shared */
+                if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) < 0)
+                        goto child_fail;
+
                 if (mount_all(arg_directory) < 0)
                         goto child_fail;
 
@@ -770,7 +785,9 @@ int main(int argc, char *argv[]) {
                         goto child_fail;
                 }
 
-                umask(0002);
+                umask(0022);
+
+                loopback_setup();
 
                 if (drop_capabilities() < 0)
                         goto child_fail;
@@ -808,9 +825,9 @@ int main(int argc, char *argv[]) {
                         }
                 }
 
-                if ((asprintf((char**)(envp + 2), "HOME=%s", home? home: "/root") < 0) ||
-                    (asprintf((char**)(envp + 3), "USER=%s", arg_user? arg_user : "root") < 0) ||
-                    (asprintf((char**)(envp + 4), "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;
                 }