Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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;
+}