diff options
Diffstat (limited to '')
| -rw-r--r-- | src/notify/meson.build | 9 | ||||
| -rw-r--r-- | src/notify/notify.c | 473 |
2 files changed, 482 insertions, 0 deletions
diff --git a/src/notify/meson.build b/src/notify/meson.build new file mode 100644 index 0000000..3baa086 --- /dev/null +++ b/src/notify/meson.build @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: LGPL-2.1-or-later + +executables += [ + executable_template + { + 'name' : 'systemd-notify', + 'public' : true, + 'sources' : files('notify.c'), + }, +] diff --git a/src/notify/notify.c b/src/notify/notify.c new file mode 100644 index 0000000..f63ec8b --- /dev/null +++ b/src/notify/notify.c @@ -0,0 +1,473 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#include "sd-daemon.h" + +#include "alloc-util.h" +#include "build.h" +#include "env-util.h" +#include "fd-util.h" +#include "fdset.h" +#include "format-util.h" +#include "log.h" +#include "main-func.h" +#include "parse-util.h" +#include "pretty-print.h" +#include "process-util.h" +#include "string-util.h" +#include "strv.h" +#include "terminal-util.h" +#include "time-util.h" +#include "user-util.h" + +static bool arg_ready = false; +static bool arg_reloading = false; +static bool arg_stopping = false; +static pid_t arg_pid = 0; +static const char *arg_status = NULL; +static bool arg_booted = false; +static uid_t arg_uid = UID_INVALID; +static gid_t arg_gid = GID_INVALID; +static bool arg_no_block = false; +static char **arg_env = NULL; +static char **arg_exec = NULL; +static FDSet *arg_fds = NULL; +static char *arg_fdname = NULL; + +STATIC_DESTRUCTOR_REGISTER(arg_env, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_exec, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_fds, fdset_freep); +STATIC_DESTRUCTOR_REGISTER(arg_fdname, freep); + +static int help(void) { + _cleanup_free_ char *link = NULL; + int r; + + r = terminal_urlify_man("systemd-notify", "1", &link); + if (r < 0) + return log_oom(); + + printf("%s [OPTIONS...] [VARIABLE=VALUE...]\n" + "%s [OPTIONS...] --exec [VARIABLE=VALUE...] ; CMDLINE...\n" + "\n%sNotify the init system about service status updates.%s\n\n" + " -h --help Show this help\n" + " --version Show package version\n" + " --ready Inform the service manager about service start-up/reload\n" + " completion\n" + " --reloading Inform the service manager about configuration reloading\n" + " --stopping Inform the service manager about service shutdown\n" + " --pid[=PID] Set main PID of daemon\n" + " --uid=USER Set user to send from\n" + " --status=TEXT Set status text\n" + " --booted Check if the system was booted up with systemd\n" + " --no-block Do not wait until operation finished\n" + " --exec Execute command line separated by ';' once done\n" + " --fd=FD Pass specified file descriptor with along with message\n" + " --fdname=NAME Name to assign to passed file descriptor(s)\n" + "\nSee the %s for details.\n", + program_invocation_short_name, + program_invocation_short_name, + ansi_highlight(), + ansi_normal(), + link); + + return 0; +} + +static pid_t manager_pid(void) { + const char *e; + pid_t pid; + int r; + + /* If we run as a service managed by systemd --user the $MANAGERPID environment variable points to + * the service manager's PID. */ + e = getenv("MANAGERPID"); + if (!e) + return 0; + + r = parse_pid(e, &pid); + if (r < 0) { + log_warning_errno(r, "$MANAGERPID is set to an invalid PID, ignoring: %s", e); + return 0; + } + + return pid; +} + +static int parse_argv(int argc, char *argv[]) { + + enum { + ARG_READY = 0x100, + ARG_RELOADING, + ARG_STOPPING, + ARG_VERSION, + ARG_PID, + ARG_STATUS, + ARG_BOOTED, + ARG_UID, + ARG_NO_BLOCK, + ARG_EXEC, + ARG_FD, + ARG_FDNAME, + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "ready", no_argument, NULL, ARG_READY }, + { "reloading", no_argument, NULL, ARG_RELOADING }, + { "stopping", no_argument, NULL, ARG_STOPPING }, + { "pid", optional_argument, NULL, ARG_PID }, + { "status", required_argument, NULL, ARG_STATUS }, + { "booted", no_argument, NULL, ARG_BOOTED }, + { "uid", required_argument, NULL, ARG_UID }, + { "no-block", no_argument, NULL, ARG_NO_BLOCK }, + { "exec", no_argument, NULL, ARG_EXEC }, + { "fd", required_argument, NULL, ARG_FD }, + { "fdname", required_argument, NULL, ARG_FDNAME }, + {} + }; + + _cleanup_fdset_free_ FDSet *passed = NULL; + bool do_exec = false; + int c, r, n_env; + + assert(argc >= 0); + assert(argv); + + while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { + + switch (c) { + + case 'h': + return help(); + + case ARG_VERSION: + return version(); + + case ARG_READY: + arg_ready = true; + break; + + case ARG_RELOADING: + arg_reloading = true; + break; + + case ARG_STOPPING: + arg_stopping = true; + break; + + case ARG_PID: + if (isempty(optarg) || streq(optarg, "auto")) { + arg_pid = getppid(); + + if (arg_pid <= 1 || + arg_pid == manager_pid()) /* Don't send from PID 1 or the service + * manager's PID (which might be distinct from + * 1, if we are a --user instance), that'd just + * be confusing for the service manager */ + arg_pid = getpid_cached(); + } else if (streq(optarg, "parent")) + arg_pid = getppid(); + else if (streq(optarg, "self")) + arg_pid = getpid_cached(); + else { + r = parse_pid(optarg, &arg_pid); + if (r < 0) + return log_error_errno(r, "Failed to parse PID %s.", optarg); + } + + break; + + case ARG_STATUS: + arg_status = optarg; + break; + + case ARG_BOOTED: + arg_booted = true; + break; + + case ARG_UID: { + const char *u = optarg; + + r = get_user_creds(&u, &arg_uid, &arg_gid, NULL, NULL, 0); + if (r == -ESRCH) /* If the user doesn't exist, then accept it anyway as numeric */ + r = parse_uid(u, &arg_uid); + if (r < 0) + return log_error_errno(r, "Can't resolve user %s: %m", optarg); + + break; + } + + case ARG_NO_BLOCK: + arg_no_block = true; + break; + + case ARG_EXEC: + do_exec = true; + break; + + case ARG_FD: { + _cleanup_close_ int owned_fd = -EBADF; + int fdnr; + + fdnr = parse_fd(optarg); + if (fdnr < 0) + return log_error_errno(fdnr, "Failed to parse file descriptor: %s", optarg); + + if (!passed) { + /* Take possession of all passed fds */ + r = fdset_new_fill(/* filter_cloexec= */ 0, &passed); + if (r < 0) + return log_error_errno(r, "Failed to take possession of passed file descriptors: %m"); + } + + if (fdnr < 3) { + /* For stdin/stdout/stderr we want to keep the fd, too, hence make a copy */ + owned_fd = fcntl(fdnr, F_DUPFD_CLOEXEC, 3); + if (owned_fd < 0) + return log_error_errno(errno, "Failed to duplicate file descriptor: %m"); + } else { + /* Otherwise, move the fd over */ + owned_fd = fdset_remove(passed, fdnr); + if (owned_fd < 0) + return log_error_errno(owned_fd, "Specified file descriptor '%i' not passed or specified more than once: %m", fdnr); + } + + if (!arg_fds) { + arg_fds = fdset_new(); + if (!arg_fds) + return log_oom(); + } + + r = fdset_consume(arg_fds, TAKE_FD(owned_fd)); + if (r < 0) + return log_error_errno(r, "Failed to add file descriptor to set: %m"); + break; + } + + case ARG_FDNAME: + if (!fdname_is_valid(optarg)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "File descriptor name invalid: %s", optarg); + + if (free_and_strdup(&arg_fdname, optarg) < 0) + return log_oom(); + + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached(); + } + } + + if (optind >= argc && + !arg_ready && + !arg_stopping && + !arg_reloading && + !arg_status && + !arg_pid && + !arg_booted && + fdset_isempty(arg_fds)) { + help(); + return -EINVAL; + } + + if (arg_fdname && fdset_isempty(arg_fds)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "No file descriptors passed, but --fdname= set, refusing."); + + if (do_exec) { + int i; + + for (i = optind; i < argc; i++) + if (streq(argv[i], ";")) + break; + + if (i >= argc) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "If --exec is used argument list must contain ';' separator, refusing."); + if (i+1 == argc) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Empty command line specified after ';' separator, refusing"); + + arg_exec = strv_copy_n(argv + i + 1, argc - i - 1); + if (!arg_exec) + return log_oom(); + + n_env = i - optind; + } else + n_env = argc - optind; + + if (n_env > 0) { + arg_env = strv_copy_n(argv + optind, n_env); + if (!arg_env) + return log_oom(); + } + + if (!fdset_isempty(passed)) + log_warning("Warning: %u more file descriptors passed than referenced with --fd=.", fdset_size(passed)); + + return 1; +} + +static int run(int argc, char* argv[]) { + _cleanup_free_ char *status = NULL, *cpid = NULL, *n = NULL, *monotonic_usec = NULL, *fdn = NULL; + _cleanup_strv_free_ char **final_env = NULL; + char* our_env[9]; + size_t i = 0; + pid_t source_pid; + int r; + + log_show_color(true); + log_parse_environment(); + log_open(); + + r = parse_argv(argc, argv); + if (r <= 0) + return r; + + if (arg_booted) { + r = sd_booted(); + if (r < 0) + log_debug_errno(r, "Failed to determine whether we are booted with systemd, assuming we aren't: %m"); + else + log_debug("The system %s booted with systemd.", r ? "was" : "was not"); + + return r <= 0; + } + + if (arg_reloading) { + our_env[i++] = (char*) "RELOADING=1"; + + if (asprintf(&monotonic_usec, "MONOTONIC_USEC=" USEC_FMT, now(CLOCK_MONOTONIC)) < 0) + return log_oom(); + + our_env[i++] = monotonic_usec; + } + + if (arg_ready) + our_env[i++] = (char*) "READY=1"; + + if (arg_stopping) + our_env[i++] = (char*) "STOPPING=1"; + + if (arg_status) { + status = strjoin("STATUS=", arg_status); + if (!status) + return log_oom(); + + our_env[i++] = status; + } + + if (arg_pid > 0) { + if (asprintf(&cpid, "MAINPID="PID_FMT, arg_pid) < 0) + return log_oom(); + + our_env[i++] = cpid; + } + + if (!fdset_isempty(arg_fds)) { + our_env[i++] = (char*) "FDSTORE=1"; + + if (arg_fdname) { + fdn = strjoin("FDNAME=", arg_fdname); + if (!fdn) + return log_oom(); + + our_env[i++] = fdn; + } + } + + our_env[i++] = NULL; + + final_env = strv_env_merge(our_env, arg_env); + if (!final_env) + return log_oom(); + + if (strv_isempty(final_env)) + return 0; + + n = strv_join(final_env, "\n"); + if (!n) + return log_oom(); + + /* If this is requested change to the requested UID/GID. Note that we only change the real UID here, and leave + the effective UID in effect (which is 0 for this to work). That's because we want the privileges to fake the + ucred data, and sd_pid_notify() uses the real UID for filling in ucred. */ + + if (arg_gid != GID_INVALID && + setregid(arg_gid, GID_INVALID) < 0) + return log_error_errno(errno, "Failed to change GID: %m"); + + if (arg_uid != UID_INVALID && + setreuid(arg_uid, UID_INVALID) < 0) + return log_error_errno(errno, "Failed to change UID: %m"); + + if (arg_pid > 0) + source_pid = arg_pid; + else { + /* Pretend the message originates from our parent, given that we are typically called from a + * shell script, i.e. we are not the main process of a service but only a child of it. */ + source_pid = getppid(); + if (source_pid <= 1 || + source_pid == manager_pid()) /* safety check: don't claim we'd send anything from PID 1 + * or the service manager itself */ + source_pid = 0; + } + + if (fdset_isempty(arg_fds)) + r = sd_pid_notify(source_pid, /* unset_environment= */ false, n); + else { + _cleanup_free_ int *a = NULL; + int k; + + k = fdset_to_array(arg_fds, &a); + if (k < 0) + return log_error_errno(k, "Failed to convert file descriptor set to array: %m"); + + r = sd_pid_notify_with_fds(source_pid, /* unset_environment= */ false, n, a, k); + + } + if (r < 0) + return log_error_errno(r, "Failed to notify init system: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), + "No status data could be sent: $NOTIFY_SOCKET was not set"); + + arg_fds = fdset_free(arg_fds); /* Close before we execute anything */ + + if (!arg_no_block) { + r = sd_pid_notify_barrier(source_pid, /* unset_environment= */ false, 5 * USEC_PER_SEC); + if (r < 0) + return log_error_errno(r, "Failed to invoke barrier: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), + "No status data could be sent: $NOTIFY_SOCKET was not set"); + } + + if (arg_exec) { + _cleanup_free_ char *cmdline = NULL; + + execvp(arg_exec[0], arg_exec); + + cmdline = strv_join(arg_exec, " "); + if (!cmdline) + return log_oom(); + + return log_error_errno(errno, "Failed to execute command line: %s", cmdline); + } + + /* The DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE() boilerplate will send the exit status via + * sd_notify(). Which is normally fine, but very confusing in systemd-notify, whose purpose is to + * send user-controllable notification messages, and not implicit ones. Let's turn if off, by + * unsetting the $NOTIFY_SOCKET environment variable. */ + (void) unsetenv("NOTIFY_SOCKET"); + return 0; +} + +DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run); |