X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fnamespace.c;h=c034bfd161f0a287deb027302fe523dbb0df564b;hp=926ff7133b98e21f881158134817cf88c74b2b89;hb=d3b1c5083359faa6cfca81810cf87ef70d0290f6;hpb=76cd584b8d6e0df5f662f193803ce2bdc530ac86

diff --git a/src/core/namespace.c b/src/core/namespace.c
index 926ff7133..c034bfd16 100644
--- a/src/core/namespace.c
+++ b/src/core/namespace.c
@@ -39,6 +39,9 @@
 #include "missing.h"
 #include "execute.h"
 #include "loopback-setup.h"
+#include "mkdir.h"
+#include "dev-setup.h"
+#include "def.h"
 
 typedef enum MountMode {
         /* This is ordered by priority! */
@@ -46,6 +49,7 @@ typedef enum MountMode {
         READONLY,
         PRIVATE_TMP,
         PRIVATE_VAR_TMP,
+        PRIVATE_DEV,
         READWRITE
 } MountMode;
 
@@ -129,6 +133,77 @@ static void drop_duplicates(BindMount *m, unsigned *n) {
         *n = t - m;
 }
 
+static int mount_dev(BindMount *m) {
+        static const char devnodes[] =
+                "/dev/null\0"
+                "/dev/zero\0"
+                "/dev/full\0"
+                "/dev/random\0"
+                "/dev/urandom\0"
+                "/dev/tty\0";
+
+        struct stat devnodes_stat[6] = {};
+        const char *d;
+        unsigned n = 0;
+        _cleanup_umask_ mode_t u;
+        int r;
+
+        assert(m);
+
+        u = umask(0000);
+
+        /* First: record device mode_t and dev_t */
+        NULSTR_FOREACH(d, devnodes) {
+                r = stat(d, &devnodes_stat[n]);
+                if (r < 0) {
+                        if (errno != ENOENT)
+                                return -errno;
+                } else {
+                        if (!S_ISBLK(devnodes_stat[n].st_mode) &&
+                            !S_ISCHR(devnodes_stat[n].st_mode))
+                                return -EINVAL;
+                }
+
+                n++;
+        }
+
+        assert(n == ELEMENTSOF(devnodes_stat));
+
+        r = mount("tmpfs", "/dev", "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=755");
+        if (r < 0)
+                return m->ignore ? 0 : -errno;
+
+
+        mkdir_p("/dev/pts", 0755);
+
+        r = mount("devpts", "/dev/pts", "devpts", MS_NOSUID|MS_NOEXEC, "newinstance,ptmxmode=0666,mode=620,gid=" STRINGIFY(TTY_GID));
+        if (r < 0)
+                return m->ignore ? 0 : -errno;
+
+        mkdir_p("/dev/shm", 0755);
+
+        r = mount("tmpfs", "/dev/shm", "tmpfs", MS_NOSUID|MS_NODEV|MS_STRICTATIME, "mode=1777");
+        if (r < 0)
+                return m->ignore ? 0 : -errno;
+
+        /* Second: actually create it */
+        n = 0;
+        NULSTR_FOREACH(d, devnodes) {
+                if (devnodes_stat[n].st_rdev == 0)
+                        continue;
+
+                r = mknod(d, devnodes_stat[n].st_mode, devnodes_stat[n].st_rdev);
+                if (r < 0)
+                        return m->ignore ? 0 : -errno;
+
+                n++;
+        }
+
+        dev_setup(NULL);
+
+        return 0;
+}
+
 static int apply_mount(
                 BindMount *m,
                 const char *tmp_dir,
@@ -141,6 +216,9 @@ static int apply_mount(
 
         switch (m->mode) {
 
+        case PRIVATE_DEV:
+                return mount_dev(m);
+
         case INACCESSIBLE:
                 what = "/run/systemd/inaccessible";
                 break;
@@ -194,6 +272,7 @@ int setup_namespace(
                 char** inaccessible_dirs,
                 char* tmp_dir,
                 char* var_tmp_dir,
+                bool private_dev,
                 unsigned mount_flags) {
 
         BindMount *m, *mounts = NULL;
@@ -209,7 +288,8 @@ int setup_namespace(
         n = !!tmp_dir + !!var_tmp_dir +
                 strv_length(read_write_dirs) +
                 strv_length(read_only_dirs) +
-                strv_length(inaccessible_dirs);
+                strv_length(inaccessible_dirs) +
+                private_dev;
 
         if (n > 0) {
                 m = mounts = (BindMount *) alloca(n * sizeof(BindMount));
@@ -237,6 +317,12 @@ int setup_namespace(
                         m++;
                 }
 
+                if (private_dev) {
+                        m->path = "/dev";
+                        m->mode = PRIVATE_DEV;
+                        m++;
+                }
+
                 assert(mounts + n == m);
 
                 qsort(mounts, n, sizeof(BindMount), mount_path_compare);
@@ -278,12 +364,22 @@ fail:
 
 static int setup_one_tmp_dir(const char *id, const char *prefix, char **path) {
         _cleanup_free_ char *x = NULL;
+        char bid[SD_ID128_STRING_MAX];
+        sd_id128_t boot_id;
+        int r;
 
         assert(id);
         assert(prefix);
         assert(path);
 
-        x = strjoin(prefix, "/systemd-", id, "-XXXXXX", NULL);
+        /* We include the boot id in the directory so that after a
+         * reboot we can easily identify obsolete directories. */
+
+        r = sd_id128_get_boot(&boot_id);
+        if (r < 0)
+                return r;
+
+        x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX", NULL);
         if (!x)
                 return -ENOMEM;