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-rw-r--r--src/activate/activate.c509
1 files changed, 509 insertions, 0 deletions
diff --git a/src/activate/activate.c b/src/activate/activate.c
new file mode 100644
index 0000000..9a83bc7
--- /dev/null
+++ b/src/activate/activate.c
@@ -0,0 +1,509 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <getopt.h>
+#include <sys/epoll.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "sd-daemon.h"
+
+#include "alloc-util.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "log.h"
+#include "macro.h"
+#include "pretty-print.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+
+static char** arg_listen = NULL;
+static bool arg_accept = false;
+static int arg_socket_type = SOCK_STREAM;
+static char** arg_args = NULL;
+static char** arg_setenv = NULL;
+static char **arg_fdnames = NULL;
+static bool arg_inetd = false;
+
+static int add_epoll(int epoll_fd, int fd) {
+ struct epoll_event ev = {
+ .events = EPOLLIN,
+ .data.fd = fd,
+ };
+
+ assert(epoll_fd >= 0);
+ assert(fd >= 0);
+
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
+ return log_error_errno(errno, "Failed to add event on epoll fd:%d for fd:%d: %m", epoll_fd, fd);
+
+ return 0;
+}
+
+static int open_sockets(int *epoll_fd, bool accept) {
+ char **address;
+ int n, fd, r;
+ int count = 0;
+
+ n = sd_listen_fds(true);
+ if (n < 0)
+ return log_error_errno(n, "Failed to read listening file descriptors from environment: %m");
+ if (n > 0) {
+ log_info("Received %i descriptors via the environment.", n);
+
+ for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++) {
+ r = fd_cloexec(fd, arg_accept);
+ if (r < 0)
+ return r;
+
+ count++;
+ }
+ }
+
+ /* Close logging and all other descriptors */
+ if (arg_listen) {
+ int except[3 + n];
+
+ for (fd = 0; fd < SD_LISTEN_FDS_START + n; fd++)
+ except[fd] = fd;
+
+ log_close();
+ close_all_fds(except, 3 + n);
+ }
+
+ /** Note: we leak some fd's on error here. I doesn't matter
+ * much, since the program will exit immediately anyway, but
+ * would be a pain to fix.
+ */
+
+ STRV_FOREACH(address, arg_listen) {
+ fd = make_socket_fd(LOG_DEBUG, *address, arg_socket_type, (arg_accept*SOCK_CLOEXEC));
+ if (fd < 0) {
+ log_open();
+ return log_error_errno(fd, "Failed to open '%s': %m", *address);
+ }
+
+ assert(fd == SD_LISTEN_FDS_START + count);
+ count++;
+ }
+
+ if (arg_listen)
+ log_open();
+
+ *epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+ if (*epoll_fd < 0)
+ return log_error_errno(errno, "Failed to create epoll object: %m");
+
+ for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + count; fd++) {
+ _cleanup_free_ char *name = NULL;
+
+ getsockname_pretty(fd, &name);
+ log_info("Listening on %s as %i.", strna(name), fd);
+
+ r = add_epoll(*epoll_fd, fd);
+ if (r < 0)
+ return r;
+ }
+
+ return count;
+}
+
+static int exec_process(const char* name, char **argv, char **env, int start_fd, size_t n_fds) {
+
+ _cleanup_strv_free_ char **envp = NULL;
+ _cleanup_free_ char *joined = NULL;
+ size_t n_env = 0, length;
+ const char *tocopy;
+ char **s;
+ int r;
+
+ if (arg_inetd && n_fds != 1)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "--inetd only supported for single file descriptors.");
+
+ length = strv_length(arg_setenv);
+
+ /* PATH, TERM, HOME, USER, LISTEN_FDS, LISTEN_PID, LISTEN_FDNAMES, NULL */
+ envp = new0(char *, length + 8);
+ if (!envp)
+ return log_oom();
+
+ STRV_FOREACH(s, arg_setenv) {
+
+ if (strchr(*s, '=')) {
+ char *k;
+
+ k = strdup(*s);
+ if (!k)
+ return log_oom();
+
+ envp[n_env++] = k;
+ } else {
+ _cleanup_free_ char *p;
+ const char *n;
+
+ p = strappend(*s, "=");
+ if (!p)
+ return log_oom();
+
+ n = strv_find_prefix(env, p);
+ if (!n)
+ continue;
+
+ envp[n_env] = strdup(n);
+ if (!envp[n_env])
+ return log_oom();
+
+ n_env++;
+ }
+ }
+
+ FOREACH_STRING(tocopy, "TERM=", "PATH=", "USER=", "HOME=") {
+ const char *n;
+
+ n = strv_find_prefix(env, tocopy);
+ if (!n)
+ continue;
+
+ envp[n_env] = strdup(n);
+ if (!envp[n_env])
+ return log_oom();
+
+ n_env++;
+ }
+
+ if (arg_inetd) {
+ assert(n_fds == 1);
+
+ r = rearrange_stdio(start_fd, start_fd, STDERR_FILENO); /* invalidates start_fd on success + error */
+ if (r < 0)
+ return log_error_errno(r, "Failed to move fd to stdin+stdout: %m");
+
+ } else {
+ if (start_fd != SD_LISTEN_FDS_START) {
+ assert(n_fds == 1);
+
+ if (dup2(start_fd, SD_LISTEN_FDS_START) < 0)
+ return log_error_errno(errno, "Failed to dup connection: %m");
+
+ safe_close(start_fd);
+ start_fd = SD_LISTEN_FDS_START;
+ }
+
+ if (asprintf((char**)(envp + n_env++), "LISTEN_FDS=%zu", n_fds) < 0)
+ return log_oom();
+
+ if (asprintf((char**)(envp + n_env++), "LISTEN_PID=" PID_FMT, getpid_cached()) < 0)
+ return log_oom();
+
+ if (arg_fdnames) {
+ _cleanup_free_ char *names = NULL;
+ size_t len;
+ char *e;
+
+ len = strv_length(arg_fdnames);
+ if (len == 1) {
+ size_t i;
+
+ for (i = 1; i < n_fds; i++) {
+ r = strv_extend(&arg_fdnames, arg_fdnames[0]);
+ if (r < 0)
+ return log_error_errno(r, "Failed to extend strv: %m");
+ }
+ } else if (len != n_fds)
+ log_warning("The number of fd names is different than number of fds: %zu vs %zu", len, n_fds);
+
+ names = strv_join(arg_fdnames, ":");
+ if (!names)
+ return log_oom();
+
+ e = strappend("LISTEN_FDNAMES=", names);
+ if (!e)
+ return log_oom();
+
+ envp[n_env++] = e;
+ }
+ }
+
+ joined = strv_join(argv, " ");
+ if (!joined)
+ return log_oom();
+
+ log_info("Execing %s (%s)", name, joined);
+ execvpe(name, argv, envp);
+
+ return log_error_errno(errno, "Failed to execp %s (%s): %m", name, joined);
+}
+
+static int fork_and_exec_process(const char* child, char** argv, char **env, int fd) {
+ _cleanup_free_ char *joined = NULL;
+ pid_t child_pid;
+ int r;
+
+ joined = strv_join(argv, " ");
+ if (!joined)
+ return log_oom();
+
+ r = safe_fork("(activate)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &child_pid);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ /* In the child */
+ exec_process(child, argv, env, fd, 1);
+ _exit(EXIT_FAILURE);
+ }
+
+ log_info("Spawned %s (%s) as PID " PID_FMT ".", child, joined, child_pid);
+ return 0;
+}
+
+static int do_accept(const char* name, char **argv, char **envp, int fd) {
+ _cleanup_free_ char *local = NULL, *peer = NULL;
+ _cleanup_close_ int fd_accepted = -1;
+
+ fd_accepted = accept4(fd, NULL, NULL, 0);
+ if (fd_accepted < 0)
+ return log_error_errno(errno, "Failed to accept connection on fd:%d: %m", fd);
+
+ getsockname_pretty(fd_accepted, &local);
+ getpeername_pretty(fd_accepted, true, &peer);
+ log_info("Connection from %s to %s", strna(peer), strna(local));
+
+ return fork_and_exec_process(name, argv, envp, fd_accepted);
+}
+
+/* SIGCHLD handler. */
+static void sigchld_hdl(int sig) {
+ PROTECT_ERRNO;
+
+ for (;;) {
+ siginfo_t si;
+ int r;
+
+ si.si_pid = 0;
+ r = waitid(P_ALL, 0, &si, WEXITED|WNOHANG);
+ if (r < 0) {
+ if (errno != ECHILD)
+ log_error_errno(errno, "Failed to reap children: %m");
+ return;
+ }
+ if (si.si_pid == 0)
+ return;
+
+ log_info("Child %d died with code %d", si.si_pid, si.si_status);
+ }
+}
+
+static int install_chld_handler(void) {
+ static const struct sigaction act = {
+ .sa_flags = SA_NOCLDSTOP|SA_RESTART,
+ .sa_handler = sigchld_hdl,
+ };
+
+ if (sigaction(SIGCHLD, &act, 0) < 0)
+ return log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
+
+ return 0;
+}
+
+static int help(void) {
+ _cleanup_free_ char *link = NULL;
+ int r;
+
+ r = terminal_urlify_man("systemd-socket-activate", "1", &link);
+ if (r < 0)
+ return log_oom();
+
+ printf("%s [OPTIONS...]\n\n"
+ "Listen on sockets and launch child on connection.\n\n"
+ "Options:\n"
+ " -h --help Show this help and exit\n"
+ " --version Print version string and exit\n"
+ " -l --listen=ADDR Listen for raw connections at ADDR\n"
+ " -d --datagram Listen on datagram instead of stream socket\n"
+ " --seqpacket Listen on SOCK_SEQPACKET instead of stream socket\n"
+ " -a --accept Spawn separate child for each connection\n"
+ " -E --setenv=NAME[=VALUE] Pass an environment variable to children\n"
+ " --fdname=NAME[:NAME...] Specify names for file descriptors\n"
+ " --inetd Enable inetd file descriptor passing protocol\n"
+ "\nNote: file descriptors from sd_listen_fds() will be passed through.\n"
+ "\nSee the %s for details.\n"
+ , program_invocation_short_name
+ , link
+ );
+
+ return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+ enum {
+ ARG_VERSION = 0x100,
+ ARG_FDNAME,
+ ARG_SEQPACKET,
+ ARG_INETD,
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ { "datagram", no_argument, NULL, 'd' },
+ { "seqpacket", no_argument, NULL, ARG_SEQPACKET },
+ { "listen", required_argument, NULL, 'l' },
+ { "accept", no_argument, NULL, 'a' },
+ { "setenv", required_argument, NULL, 'E' },
+ { "environment", required_argument, NULL, 'E' }, /* legacy alias */
+ { "fdname", required_argument, NULL, ARG_FDNAME },
+ { "inetd", no_argument, NULL, ARG_INETD },
+ {}
+ };
+
+ int c, r;
+
+ assert(argc >= 0);
+ assert(argv);
+
+ while ((c = getopt_long(argc, argv, "+hl:aE:d", options, NULL)) >= 0)
+ switch(c) {
+ case 'h':
+ return help();
+
+ case ARG_VERSION:
+ return version();
+
+ case 'l':
+ r = strv_extend(&arg_listen, optarg);
+ if (r < 0)
+ return log_oom();
+
+ break;
+
+ case 'd':
+ if (arg_socket_type == SOCK_SEQPACKET)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "--datagram may not be combined with --seqpacket.");
+
+ arg_socket_type = SOCK_DGRAM;
+ break;
+
+ case ARG_SEQPACKET:
+ if (arg_socket_type == SOCK_DGRAM)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "--seqpacket may not be combined with --datagram.");
+
+ arg_socket_type = SOCK_SEQPACKET;
+ break;
+
+ case 'a':
+ arg_accept = true;
+ break;
+
+ case 'E':
+ r = strv_extend(&arg_setenv, optarg);
+ if (r < 0)
+ return log_oom();
+
+ break;
+
+ case ARG_FDNAME: {
+ _cleanup_strv_free_ char **names;
+ char **s;
+
+ names = strv_split(optarg, ":");
+ if (!names)
+ return log_oom();
+
+ STRV_FOREACH(s, names)
+ if (!fdname_is_valid(*s)) {
+ _cleanup_free_ char *esc;
+
+ esc = cescape(*s);
+ log_warning("File descriptor name \"%s\" is not valid.", esc);
+ }
+
+ /* Empty optargs means one empty name */
+ r = strv_extend_strv(&arg_fdnames,
+ strv_isempty(names) ? STRV_MAKE("") : names,
+ false);
+ if (r < 0)
+ return log_error_errno(r, "strv_extend_strv: %m");
+ break;
+ }
+
+ case ARG_INETD:
+ arg_inetd = true;
+ break;
+
+ case '?':
+ return -EINVAL;
+
+ default:
+ assert_not_reached("Unhandled option");
+ }
+
+ if (optind == argc)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "%s: command to execute is missing.",
+ program_invocation_short_name);
+
+ if (arg_socket_type == SOCK_DGRAM && arg_accept)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Datagram sockets do not accept connections. "
+ "The --datagram and --accept options may not be combined.");
+
+ arg_args = argv + optind;
+
+ return 1 /* work to do */;
+}
+
+int main(int argc, char **argv, char **envp) {
+ int r, n;
+ int epoll_fd = -1;
+
+ log_parse_environment();
+ log_open();
+
+ r = parse_argv(argc, argv);
+ if (r <= 0)
+ return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+
+ r = install_chld_handler();
+ if (r < 0)
+ return EXIT_FAILURE;
+
+ n = open_sockets(&epoll_fd, arg_accept);
+ if (n < 0)
+ return EXIT_FAILURE;
+ if (n == 0) {
+ log_error("No sockets to listen on specified or passed in.");
+ return EXIT_FAILURE;
+ }
+
+ for (;;) {
+ struct epoll_event event;
+
+ if (epoll_wait(epoll_fd, &event, 1, -1) < 0) {
+ if (errno == EINTR)
+ continue;
+
+ log_error_errno(errno, "epoll_wait() failed: %m");
+ return EXIT_FAILURE;
+ }
+
+ log_info("Communication attempt on fd %i.", event.data.fd);
+ if (arg_accept) {
+ r = do_accept(argv[optind], argv + optind, envp, event.data.fd);
+ if (r < 0)
+ return EXIT_FAILURE;
+ } else
+ break;
+ }
+
+ exec_process(argv[optind], argv + optind, envp, SD_LISTEN_FDS_START, (size_t) n);
+
+ return EXIT_SUCCESS;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 17:48:37 +0000