nspawn: fix reboot event fd reuse

[elogind.git] / src / nspawn / nspawn.c

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 241b4b5393a1f81988a277583db61fd722cd50b4..5352b95ec69776b20c103ac6a1a4736dfe870fa8 100644 (file)
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -40,6 +40,7 @@
 #include <sys/un.h>
 #include <sys/socket.h>
 #include <linux/netlink.h>
+#include <sys/eventfd.h>
 
 #include "sd-daemon.h"
 #include "sd-bus.h"
@@ -63,10 +64,7 @@
 #include "ptyfwd.h"
 #include "bus-kernel.h"
 #include "env-util.h"
-
-#ifndef TTY_GID
-#define TTY_GID 5
-#endif
+#include "def.h"
 
 typedef enum LinkJournal {
         LINK_NO,
@@ -109,7 +107,8 @@ static uint64_t arg_retain =
         (1ULL << CAP_SYS_RESOURCE) |
         (1ULL << CAP_SYS_BOOT) |
         (1ULL << CAP_AUDIT_WRITE) |
-        (1ULL << CAP_AUDIT_CONTROL);
+        (1ULL << CAP_AUDIT_CONTROL) |
+        (1ULL << CAP_MKNOD);
 static char **arg_bind = NULL;
 static char **arg_bind_ro = NULL;
 static char **arg_setenv = NULL;
@@ -638,40 +637,30 @@ static int copy_devnodes(const char *dest) {
         u = umask(0000);
 
         NULSTR_FOREACH(d, devnodes) {
-                struct stat st;
                 _cleanup_free_ char *from = NULL, *to = NULL;
+                struct stat st;
 
-                asprintf(&from, "/dev/%s", d);
-                asprintf(&to, "%s/dev/%s", dest, d);
-
-                if (!from || !to) {
-                        log_oom();
-
-                        if (r == 0)
-                                r = -ENOMEM;
-
-                        break;
-                }
+                from = strappend("/dev/", d);
+                to = strjoin(dest, "/dev/", d, NULL);
+                if (!from || !to)
+                        return log_oom();
 
                 if (stat(from, &st) < 0) {
 
                         if (errno != ENOENT) {
                                 log_error("Failed to stat %s: %m", from);
-                                if (r == 0)
-                                        r = -errno;
+                                return -errno;
                         }
 
                 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
 
                         log_error("%s is not a char or block device, cannot copy", from);
-                        if (r == 0)
-                                r = -EIO;
+                        return -EIO;
 
                 } else if (mknod(to, st.st_mode, st.st_rdev) < 0) {
 
                         log_error("mknod(%s) failed: %m", dest);
-                        if (r == 0)
-                                r = -errno;
+                        return  -errno;
                 }
         }
 
@@ -996,7 +985,7 @@ static int drop_capabilities(void) {
         return capability_bounding_set_drop(~arg_retain, false);
 }
 
-static int register_machine(void) {
+static int register_machine(pid_t pid) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_unref_ sd_bus *bus = NULL;
         int r;
@@ -1020,7 +1009,7 @@ static int register_machine(void) {
                         SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
                         "nspawn",
                         "container",
-                        (uint32_t) 0,
+                        (uint32_t) pid,
                         strempty(arg_directory),
                         !isempty(arg_slice), "Slice", "s", arg_slice);
         if (r < 0) {
@@ -1097,7 +1086,7 @@ static bool audit_enabled(void) {
 int main(int argc, char *argv[]) {
         pid_t pid = 0;
         int r = EXIT_FAILURE, k;
-        _cleanup_close_ int master = -1, kdbus_fd = -1;
+        _cleanup_close_ int master = -1, kdbus_fd = -1, sync_fd = -1;
         int n_fd_passed;
         const char *console = NULL;
         sigset_t mask;
@@ -1213,7 +1202,7 @@ int main(int argc, char *argv[]) {
                 log_debug("Successfully created kdbus namespace as %s", kdbus_namespace);
 
         if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
-                log_error("Failed to create kmsg socket pair.");
+                log_error("Failed to create kmsg socket pair: %m");
                 goto finish;
         }
 
@@ -1226,6 +1215,12 @@ int main(int argc, char *argv[]) {
         for (;;) {
                 siginfo_t status;
 
+                sync_fd = eventfd(0, EFD_CLOEXEC);
+                if (sync_fd < 0) {
+                        log_error("Failed to create event fd: %m");
+                        goto finish;
+                }
+
                 pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
                 if (pid < 0) {
                         if (errno == EINVAL)
@@ -1255,6 +1250,7 @@ int main(int argc, char *argv[]) {
                                 NULL
                         };
                         char **env_use;
+                        eventfd_t x;
 
                         envp[n_env] = strv_find_prefix(environ, "TERM=");
                         if (envp[n_env])
@@ -1302,10 +1298,6 @@ int main(int argc, char *argv[]) {
                                 goto child_fail;
                         }
 
-                        r = register_machine();
-                        if (r < 0)
-                                goto finish;
-
                         /* Mark everything as slave, so that we still
                          * receive mounts from the real root, but don't
                          * propagate mounts to the real root. */
@@ -1482,6 +1474,10 @@ int main(int argc, char *argv[]) {
 
                         setup_hostname();
 
+                        eventfd_read(sync_fd, &x);
+                        close_nointr_nofail(sync_fd);
+                        sync_fd = -1;
+
                         if (!strv_isempty(arg_setenv)) {
                                 char **n;
 
@@ -1529,6 +1525,14 @@ int main(int argc, char *argv[]) {
                 fdset_free(fds);
                 fds = NULL;
 
+                r = register_machine(pid);
+                if (r < 0)
+                        goto finish;
+
+                eventfd_write(sync_fd, 1);
+                close_nointr_nofail(sync_fd);
+                sync_fd = -1;
+
                 k = process_pty(master, &mask, arg_boot ? pid : 0, SIGRTMIN+3);
                 if (k < 0) {
                         r = EXIT_FAILURE;