chiark / gitweb /
nspawn: allow bind-mounting char and block files
[elogind.git] / src / nspawn / nspawn.c
index efeba596658079606376811963586f61da49df3a..25828cf3ccf01e5aadd36cbb55567bb227df2911 100644 (file)
@@ -180,6 +180,7 @@ static bool arg_register = true;
 static bool arg_keep_unit = false;
 static char **arg_network_interfaces = NULL;
 static char **arg_network_macvlan = NULL;
+static char **arg_network_ipvlan = NULL;
 static bool arg_network_veth = false;
 static const char *arg_network_bridge = NULL;
 static unsigned long arg_personality = 0xffffffffLU;
@@ -211,6 +212,9 @@ static void help(void) {
                "     --network-macvlan=INTERFACE\n"
                "                            Create a macvlan network interface based on an\n"
                "                            existing network interface to the container\n"
+               "     --network-ipvlan=INTERFACE\n"
+               "                            Create a ipvlan network interface based on an\n"
+               "                            existing network interface to the container\n"
                "  -n --network-veth         Add a virtual ethernet connection between host\n"
                "                            and container\n"
                "     --network-bridge=INTERFACE\n"
@@ -285,6 +289,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_KEEP_UNIT,
                 ARG_NETWORK_INTERFACE,
                 ARG_NETWORK_MACVLAN,
+                ARG_NETWORK_IPVLAN,
                 ARG_NETWORK_BRIDGE,
                 ARG_PERSONALITY,
                 ARG_VOLATILE,
@@ -319,6 +324,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "keep-unit",             no_argument,       NULL, ARG_KEEP_UNIT         },
                 { "network-interface",     required_argument, NULL, ARG_NETWORK_INTERFACE },
                 { "network-macvlan",       required_argument, NULL, ARG_NETWORK_MACVLAN   },
+                { "network-ipvlan",        required_argument, NULL, ARG_NETWORK_IPVLAN    },
                 { "network-veth",          no_argument,       NULL, 'n'                   },
                 { "network-bridge",        required_argument, NULL, ARG_NETWORK_BRIDGE    },
                 { "personality",           required_argument, NULL, ARG_PERSONALITY       },
@@ -401,6 +407,13 @@ static int parse_argv(int argc, char *argv[]) {
                         if (strv_extend(&arg_network_macvlan, optarg) < 0)
                                 return log_oom();
 
+                        arg_private_network = true;
+                        break;
+
+                case ARG_NETWORK_IPVLAN:
+                        if (strv_extend(&arg_network_ipvlan, optarg) < 0)
+                                return log_oom();
+
                         /* fall through */
 
                 case ARG_PRIVATE_NETWORK:
@@ -900,8 +913,12 @@ static int mount_binds(const char *dest, char **l, bool ro) {
 
                 r = stat(where, &dest_st);
                 if (r == 0) {
-                        if ((source_st.st_mode & S_IFMT) != (dest_st.st_mode & S_IFMT)) {
-                                log_error("The file types of %s and %s do not match. Refusing bind mount", *x, where);
+                        if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) {
+                                log_error("Cannot bind mount directory %s on file %s.", *x, where);
+                                return -EINVAL;
+                        }
+                        if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) {
+                                log_error("Cannot bind mount file %s on directory %s.", *x, where);
                                 return -EINVAL;
                         }
                 } else if (errno == ENOENT) {
@@ -913,27 +930,18 @@ static int mount_binds(const char *dest, char **l, bool ro) {
                         return -errno;
                 }
 
-                /* Create the mount point, but be conservative -- refuse to create block
-                 * and char devices. */
+                /* Create the mount point. Any non-directory file can be
+                 * mounted on any non-directory file (regular, fifo, socket,
+                 * char, block).
+                 */
                 if (S_ISDIR(source_st.st_mode)) {
                         r = mkdir_label(where, 0755);
                         if (r < 0 && errno != EEXIST)
                                 return log_error_errno(r, "Failed to create mount point %s: %m", where);
-                } else if (S_ISFIFO(source_st.st_mode)) {
-                        r = mkfifo(where, 0644);
-                        if (r < 0 && errno != EEXIST)
-                                return log_error_errno(errno, "Failed to create mount point %s: %m", where);
-                } else if (S_ISSOCK(source_st.st_mode)) {
-                        r = mknod(where, 0644 | S_IFSOCK, 0);
-                        if (r < 0 && errno != EEXIST)
-                                return log_error_errno(errno, "Failed to create mount point %s: %m", where);
-                } else if (S_ISREG(source_st.st_mode)) {
+                } else {
                         r = touch(where);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to create mount point %s: %m", where);
-                } else {
-                        log_error("Refusing to create mountpoint for file: %s", *x);
-                        return -ENOTSUP;
                 }
 
                 if (mount(*x, where, "bind", MS_BIND, NULL) < 0)
@@ -2381,6 +2389,87 @@ static int setup_macvlan(pid_t pid) {
         return 0;
 }
 
+static int setup_ipvlan(pid_t pid) {
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+        char **i;
+        int r;
+
+        if (!arg_private_network)
+                return 0;
+
+        if (strv_isempty(arg_network_ipvlan))
+                return 0;
+
+        r = sd_rtnl_open(&rtnl, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        udev = udev_new();
+        if (!udev) {
+                log_error("Failed to connect to udev.");
+                return -ENOMEM;
+        }
+
+        STRV_FOREACH(i, arg_network_ipvlan) {
+                _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
+                _cleanup_free_ char *n = NULL;
+                int ifi;
+
+                ifi = parse_interface(udev, *i);
+                if (ifi < 0)
+                        return ifi;
+
+                r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+                r = sd_rtnl_message_append_u32(m, IFLA_LINK, ifi);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink interface index: %m");
+
+                n = strappend("iv-", *i);
+                if (!n)
+                        return log_oom();
+
+                strshorten(n, IFNAMSIZ-1);
+
+                r = sd_rtnl_message_append_string(m, IFLA_IFNAME, n);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+                r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+                r = sd_rtnl_message_open_container(m, IFLA_LINKINFO);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open netlink container: %m");
+
+                r = sd_rtnl_message_open_container_union(m, IFLA_INFO_DATA, "ipvlan");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open netlink container: %m");
+
+                r = sd_rtnl_message_append_u16(m, IFLA_IPVLAN_MODE, IPVLAN_MODE_L2);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add ipvlan mode: %m");
+
+                r = sd_rtnl_message_close_container(m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close netlink container: %m");
+
+                r = sd_rtnl_message_close_container(m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close netlink container: %m");
+
+                r = sd_rtnl_call(rtnl, m, 0, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add new ipvlan interfaces: %m");
+        }
+
+        return 0;
+}
+
 static int setup_seccomp(void) {
 
 #ifdef HAVE_SECCOMP
@@ -2559,63 +2648,6 @@ static int setup_image(char **device_path, int *loop_nr) {
         return r;
 }
 
-static int wait_for_block_device(struct udev *udev, dev_t devnum, struct udev_device **ret) {
-        _cleanup_udev_monitor_unref_ struct udev_monitor *monitor = NULL;
-        int r;
-
-        assert(udev);
-        assert(ret);
-
-        for (;;) {
-                _cleanup_udev_device_unref_ struct udev_device *d = NULL;
-                struct pollfd pfd = {
-                        .events = POLLIN
-                };
-
-                d = udev_device_new_from_devnum(udev, 'b', devnum);
-                if (!d)
-                        return log_oom();
-
-                r = udev_device_get_is_initialized(d);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to check if device is initialized: %m");
-                if (r > 0) {
-                        *ret = d;
-                        d = NULL;
-                        return 0;
-                }
-                d = udev_device_unref(d);
-
-                if (!monitor) {
-                        monitor = udev_monitor_new_from_netlink(udev, "udev");
-                        if (!monitor)
-                                return log_oom();
-
-                        r = udev_monitor_filter_add_match_subsystem_devtype(monitor, "block", NULL);
-                        if (r < 0)
-                                return log_error_errno(r, "Failed to add block match: %m");
-
-                        r = udev_monitor_enable_receiving(monitor);
-                        if (r < 0)
-                                return log_error_errno(r, "Failed to turn on monitor: %m");
-
-                        continue;
-                }
-
-                pfd.fd = udev_monitor_get_fd(monitor);
-                if (pfd.fd < 0)
-                        return log_error_errno(r, "Failed to get udev monitor fd: %m");
-
-                r = poll(&pfd, 1, -1);
-                if (r < 0)
-                        return log_error_errno(errno, "Failed to wait for device initialization: %m");
-
-                d = udev_monitor_receive_device(monitor);
-        }
-
-        return 0;
-}
-
 #define PARTITION_TABLE_BLURB \
         "Note that the disk image needs to either contain only a single MBR partition of\n" \
         "type 0x83 that is marked bootable, or a sinlge GPT partition of type" \
@@ -2645,11 +2677,12 @@ static int dissect_image(
         _cleanup_udev_unref_ struct udev *udev = NULL;
         struct udev_list_entry *first, *item;
         bool home_rw = true, root_rw = true, secondary_root_rw = true, srv_rw = true, generic_rw = true;
+        bool is_gpt, is_mbr, multiple_generic = false;
         const char *pttype = NULL;
         blkid_partlist pl;
         struct stat st;
+        unsigned i;
         int r;
-        bool is_gpt, is_mbr, multiple_generic = false;
 
         assert(fd >= 0);
         assert(root_device);
@@ -2718,21 +2751,81 @@ static int dissect_image(
         if (fstat(fd, &st) < 0)
                 return log_error_errno(errno, "Failed to stat block device: %m");
 
-        r = wait_for_block_device(udev, st.st_rdev, &d);
-        if (r < 0)
-                return r;
-
-        e = udev_enumerate_new(udev);
-        if (!e)
+        d = udev_device_new_from_devnum(udev, 'b', st.st_rdev);
+        if (!d)
                 return log_oom();
 
-        r = udev_enumerate_add_match_parent(e, d);
-        if (r < 0)
-                return log_oom();
+        for (i = 0;; i++) {
+                int n, m;
 
-        r = udev_enumerate_scan_devices(e);
-        if (r < 0)
-                return log_error_errno(r, "Failed to scan for partition devices of %s: %m", arg_image);
+                if (i >= 10) {
+                        log_error("Kernel partitions never appeared.");
+                        return -ENXIO;
+                }
+
+                e = udev_enumerate_new(udev);
+                if (!e)
+                        return log_oom();
+
+                r = udev_enumerate_add_match_parent(e, d);
+                if (r < 0)
+                        return log_oom();
+
+                r = udev_enumerate_scan_devices(e);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to scan for partition devices of %s: %m", arg_image);
+
+                /* Count the partitions enumerated by the kernel */
+                n = 0;
+                first = udev_enumerate_get_list_entry(e);
+                udev_list_entry_foreach(item, first)
+                        n++;
+
+                /* Count the partitions enumerated by blkid */
+                m = blkid_partlist_numof_partitions(pl);
+                if (n == m + 1)
+                        break;
+                if (n > m + 1) {
+                        log_error("blkid and kernel partition list do not match.");
+                        return -EIO;
+                }
+                if (n < m + 1) {
+                        unsigned j;
+
+                        /* The kernel has probed fewer partitions than
+                         * blkid? Maybe the kernel prober is still
+                         * running or it got EBUSY because udev
+                         * already opened the device. Let's reprobe
+                         * the device, which is a synchronous call
+                         * that waits until probing is complete. */
+
+                        for (j = 0; j < 20; j++) {
+
+                                r = ioctl(fd, BLKRRPART, 0);
+                                if (r < 0)
+                                        r = -errno;
+                                if (r >= 0 || r != -EBUSY)
+                                        break;
+
+                                /* If something else has the device
+                                 * open, such as an udev rule, the
+                                 * ioctl will return EBUSY. Since
+                                 * there's no way to wait until it
+                                 * isn't busy anymore, let's just wait
+                                 * a bit, and try again.
+                                 *
+                                 * This is really something they
+                                 * should fix in the kernel! */
+
+                                usleep(50 * USEC_PER_MSEC);
+                        }
+
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to reread partition table: %m");
+                }
+
+                e = udev_enumerate_unref(e);
+        }
 
         first = udev_enumerate_get_list_entry(e);
         udev_list_entry_foreach(item, first) {
@@ -4044,6 +4137,10 @@ int main(int argc, char *argv[]) {
                         if (r < 0)
                                 goto finish;
 
+                        r = setup_ipvlan(pid);
+                        if (r < 0)
+                                goto finish;
+
                         r = register_machine(pid, ifi);
                         if (r < 0)
                                 goto finish;
@@ -4201,6 +4298,7 @@ finish:
         strv_free(arg_setenv);
         strv_free(arg_network_interfaces);
         strv_free(arg_network_macvlan);
+        strv_free(arg_network_ipvlan);
         strv_free(arg_bind);
         strv_free(arg_bind_ro);
         strv_free(arg_tmpfs);