X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fnspawn%2Fnspawn.c;h=b118c739e8c6b0f562b2daf14520d15443d420e4;hb=4212a3375e03fd12cb407b34cab59dbe4ed9f4eb;hp=bad93a5e2bf2742a8ba4488b685fbf0717519957;hpb=5aa4bb6b5b0b9dcea524d56cf8664b892a5a976a;p=elogind.git diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index bad93a5e2..b118c739e 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -40,7 +40,6 @@ #include #include #include -#include #include #include #include @@ -84,12 +83,12 @@ #include "def.h" #include "rtnl-util.h" #include "udev-util.h" -#include "eventfd-util.h" #include "blkid-util.h" #include "gpt.h" #include "siphash24.h" #include "copy.h" #include "base-filesystem.h" +#include "barrier.h" #ifdef HAVE_SECCOMP #include "seccomp-util.h" @@ -396,7 +395,7 @@ static int parse_argv(int argc, char *argv[]) { case ARG_CAPABILITY: case ARG_DROP_CAPABILITY: { - char *state, *word; + const char *state, *word; size_t length; FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) { @@ -1660,11 +1659,8 @@ static int setup_veth(pid_t pid, char iface_name[IFNAMSIZ], int *ifi) { /* Use two different interface name prefixes depending whether * we are in bridge mode or not. */ - if (arg_network_bridge) - memcpy(iface_name, "vb-", 3); - else - memcpy(iface_name, "ve-", 3); - strncpy(iface_name+3, arg_machine, IFNAMSIZ - 3); + snprintf(iface_name, IFNAMSIZ, "%s-%s", + arg_network_bridge ? "vb" : "ve", arg_machine); r = get_mac(&mac); if (r < 0) { @@ -2603,7 +2599,8 @@ static int spawn_getent(const char *database, const char *key, pid_t *rpid) { } static int change_uid_gid(char **_home) { - char line[LINE_MAX], *w, *x, *state, *u, *g, *h; + char line[LINE_MAX], *x, *u, *g, *h; + const char *word, *state; _cleanup_free_ uid_t *uids = NULL; _cleanup_free_ char *home = NULL; _cleanup_fclose_ FILE *f = NULL; @@ -2753,10 +2750,10 @@ static int change_uid_gid(char **_home) { x += strcspn(x, WHITESPACE); x += strspn(x, WHITESPACE); - FOREACH_WORD(w, l, x, state) { + FOREACH_WORD(word, l, x, state) { char c[l+1]; - memcpy(c, w, l); + memcpy(c, word, l); c[l] = 0; if (!GREEDY_REALLOC(uids, sz, n_uids+1)) @@ -3074,12 +3071,18 @@ int main(int argc, char *argv[]) { for (;;) { ContainerStatus container_status; - int eventfds[2] = { -1, -1 }; + _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL; struct sigaction sa = { .sa_handler = nop_handler, .sa_flags = SA_NOCLDSTOP, }; + r = barrier_create(&barrier); + if (r < 0) { + log_error("Cannot initialize IPC barrier: %s", strerror(-r)); + goto finish; + } + /* Child can be killed before execv(), so handle SIGCHLD * in order to interrupt parent's blocking calls and * give it a chance to call wait() and terminate. */ @@ -3095,9 +3098,9 @@ int main(int argc, char *argv[]) { goto finish; } - pid = clone_with_eventfd(SIGCHLD|CLONE_NEWNS| - (arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS)| - (arg_private_network ? CLONE_NEWNET : 0), eventfds); + pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWNS| + (arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS)| + (arg_private_network ? CLONE_NEWNET : 0), NULL); if (pid < 0) { if (errno == EINVAL) log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m"); @@ -3126,6 +3129,8 @@ int main(int argc, char *argv[]) { }; char **env_use; + barrier_set_role(&barrier, BARRIER_CHILD); + envp[n_env] = strv_find_prefix(environ, "TERM="); if (envp[n_env]) n_env ++; @@ -3151,26 +3156,26 @@ int main(int argc, char *argv[]) { } log_error("Failed to open console: %s", strerror(-k)); - goto child_fail; + _exit(EXIT_FAILURE); } if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO || dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) { log_error("Failed to duplicate console: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } if (setsid() < 0) { log_error("setsid() failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } if (reset_audit_loginuid() < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) { log_error("PR_SET_PDEATHSIG failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } /* Mark everything as slave, so that we still @@ -3178,113 +3183,109 @@ int main(int argc, char *argv[]) { * propagate mounts to the real root. */ if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) { log_error("MS_SLAVE|MS_REC failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } if (mount_devices(arg_directory, root_device, root_device_rw, home_device, home_device_rw, srv_device, srv_device_rw) < 0) - goto child_fail; + _exit(EXIT_FAILURE); /* Turn directory into bind mount */ if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) { log_error("Failed to make bind mount: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } r = setup_volatile(arg_directory); if (r < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_volatile_state(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); r = base_filesystem_create(arg_directory); if (r < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (arg_read_only) { k = bind_remount_recursive(arg_directory, true); if (k < 0) { log_error("Failed to make tree read-only: %s", strerror(-k)); - goto child_fail; + _exit(EXIT_FAILURE); } } if (mount_all(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (copy_devnodes(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_ptmx(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); dev_setup(arg_directory); if (setup_seccomp() < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_dev_console(arg_directory, console) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0) - goto child_fail; + _exit(EXIT_FAILURE); kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]); if (setup_boot_id(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_timezone(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_resolv_conf(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_journal(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (mount_binds(arg_directory, arg_bind, false) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (mount_binds(arg_directory, arg_bind_ro, true) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (mount_tmpfs(arg_directory) < 0) - goto child_fail; + _exit(EXIT_FAILURE); if (setup_kdbus(arg_directory, kdbus_domain) < 0) - goto child_fail; + _exit(EXIT_FAILURE); /* Tell the parent that we are ready, and that * it can cgroupify us to that we lack access * to certain devices and resources. */ - r = eventfd_send_state(eventfds[1], - EVENTFD_CHILD_SUCCEEDED); - eventfds[1] = safe_close(eventfds[1]); - if (r < 0) - goto child_fail; + barrier_place(&barrier); if (chdir(arg_directory) < 0) { log_error("chdir(%s) failed: %m", arg_directory); - goto child_fail; + _exit(EXIT_FAILURE); } if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) { log_error("mount(MS_MOVE) failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } if (chroot(".") < 0) { log_error("chroot() failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } if (chdir("/") < 0) { log_error("chdir() failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } umask(0022); @@ -3294,18 +3295,18 @@ int main(int argc, char *argv[]) { if (drop_capabilities() < 0) { log_error("drop_capabilities() failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } r = change_uid_gid(&home); if (r < 0) - goto child_fail; + _exit(EXIT_FAILURE); if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) || (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) || (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) { log_oom(); - goto child_fail; + _exit(EXIT_FAILURE); } if (!sd_id128_equal(arg_uuid, SD_ID128_NULL)) { @@ -3313,7 +3314,7 @@ int main(int argc, char *argv[]) { if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_format_as_uuid(arg_uuid, as_uuid)) < 0) { log_oom(); - goto child_fail; + _exit(EXIT_FAILURE); } } @@ -3321,13 +3322,13 @@ int main(int argc, char *argv[]) { k = fdset_cloexec(fds, false); if (k < 0) { log_error("Failed to unset O_CLOEXEC for file descriptors."); - goto child_fail; + _exit(EXIT_FAILURE); } if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", n_fd_passed) < 0) || (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0)) { log_oom(); - goto child_fail; + _exit(EXIT_FAILURE); } } @@ -3336,12 +3337,12 @@ int main(int argc, char *argv[]) { if (arg_personality != 0xffffffffLU) { if (personality(arg_personality) < 0) { log_error("personality() failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } } else if (secondary) { if (personality(PER_LINUX32) < 0) { log_error("personality() failed: %m"); - goto child_fail; + _exit(EXIT_FAILURE); } } @@ -3349,7 +3350,7 @@ int main(int argc, char *argv[]) { if (arg_selinux_context) if (setexeccon((security_context_t) arg_selinux_context) < 0) { log_error("setexeccon(\"%s\") failed: %m", arg_selinux_context); - goto child_fail; + _exit(EXIT_FAILURE); } #endif @@ -3359,7 +3360,7 @@ int main(int argc, char *argv[]) { n = strv_env_merge(2, envp, arg_setenv); if (!n) { log_oom(); - goto child_fail; + _exit(EXIT_FAILURE); } env_use = n; @@ -3367,10 +3368,8 @@ int main(int argc, char *argv[]) { env_use = (char**) envp; /* Wait until the parent is ready with the setup, too... */ - r = eventfd_parent_succeeded(eventfds[0]); - eventfds[0] = safe_close(eventfds[0]); - if (r < 0) - goto child_fail; + if (!barrier_place_and_sync(&barrier)) + _exit(EXIT_FAILURE); if (arg_boot) { char **a; @@ -3399,29 +3398,15 @@ int main(int argc, char *argv[]) { } log_error("execv() failed: %m"); - - child_fail: - /* Tell the parent that the setup failed, so he - * can clean up resources and terminate. */ - if (eventfds[1] != -1) - eventfd_send_state(eventfds[1], - EVENTFD_CHILD_FAILED); _exit(EXIT_FAILURE); } + barrier_set_role(&barrier, BARRIER_PARENT); fdset_free(fds); fds = NULL; - /* Wait for the child event: - * If EVENTFD_CHILD_FAILED, the child will terminate soon. - * If EVENTFD_CHILD_SUCCEEDED, the child is reporting that - * it is ready with all it needs to do with priviliges. - * After we got the notification we can make the process - * join its cgroup which might limit what it can do */ - r = eventfd_child_succeeded(eventfds[1]); - eventfds[1] = safe_close(eventfds[1]); - - if (r >= 0) { + /* wait for child-setup to be done */ + if (barrier_place_and_sync(&barrier)) { int ifi = 0; r = move_network_interfaces(pid); @@ -3458,10 +3443,7 @@ int main(int argc, char *argv[]) { /* Notify the child that the parent is ready with all * its setup, and that the child can now hand over * control to the code to run inside the container. */ - r = eventfd_send_state(eventfds[0], EVENTFD_PARENT_SUCCEEDED); - eventfds[0] = safe_close(eventfds[0]); - if (r < 0) - goto finish; + barrier_place(&barrier); k = process_pty(master, &mask, arg_boot ? pid : 0, SIGRTMIN+3); if (k < 0) {