/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <sys/socket.h> #include <sys/un.h> #include <sys/types.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #include <errno.h> #include <sys/poll.h> #include <stddef.h> #include <getopt.h> #include "log.h" #include "util.h" #include "socket-util.h" #include "sd-daemon.h" #include "sd-bus.h" #include "bus-internal.h" #include "bus-message.h" #include "bus-util.h" #include "build.h" #include "strv.h" #include "def.h" static const char *arg_address = DEFAULT_SYSTEM_BUS_PATH; static char *arg_command_line_buffer = NULL; static int help(void) { printf("%s [OPTIONS...]\n\n" "Connect STDIO or a socket to a given bus address.\n\n" " -h --help Show this help\n" " --version Show package version\n" " --address=ADDRESS Connect to the bus specified by ADDRESS\n" " (default: " DEFAULT_SYSTEM_BUS_PATH ")\n", program_invocation_short_name); return 0; } static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_ADDRESS, }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, ARG_VERSION }, { "address", required_argument, NULL, ARG_ADDRESS }, { NULL, 0, NULL, 0 } }; int c; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { switch (c) { case 'h': help(); return 0; case ARG_VERSION: puts(PACKAGE_STRING); puts(SYSTEMD_FEATURES); return 0; case ARG_ADDRESS: arg_address = optarg; break; case '?': return -EINVAL; default: assert_not_reached("Unhandled option"); } } /* If the first command line argument is only "x" characters * we'll write who we are talking to into it, so that "ps" is * explanatory */ arg_command_line_buffer = argv[optind]; if (argc > optind + 1 || (arg_command_line_buffer && arg_command_line_buffer[strspn(arg_command_line_buffer, "x")] != 0)) { log_error("Too many arguments"); return -EINVAL; } return 1; } static int rename_service(sd_bus *a, sd_bus *b) { _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL; _cleanup_free_ char *p = NULL, *name = NULL; const char *comm; char **cmdline; uid_t uid; pid_t pid; int r; assert(a); assert(b); r = sd_bus_get_peer_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM, &creds); if (r < 0) return r; r = sd_bus_creds_get_uid(creds, &uid); if (r < 0) return r; r = sd_bus_creds_get_pid(creds, &pid); if (r < 0) return r; r = sd_bus_creds_get_cmdline(creds, &cmdline); if (r < 0) return r; r = sd_bus_creds_get_comm(creds, &comm); if (r < 0) return r; name = uid_to_name(uid); if (!name) return -ENOMEM; p = strv_join(cmdline, " "); if (!p) return -ENOMEM; /* The status string gets the full command line ... */ sd_notifyf(false, "STATUS=Processing requests from client PID %lu (%s); UID %lu (%s)", (unsigned long) pid, p, (unsigned long) uid, name); /* ... and the argv line only the short comm */ if (arg_command_line_buffer) { size_t m, w; m = strlen(arg_command_line_buffer); w = snprintf(arg_command_line_buffer, m, "[PID %lu/%s; UID %lu/%s]", (unsigned long) pid, comm, (unsigned long) uid, name); if (m > w) memset(arg_command_line_buffer + w, 0, m - w); } log_debug("Running on behalf of PID %lu (%s), UID %lu (%s), %s", (unsigned long) pid, p, (unsigned long) uid, name, a->unique_name); ; return 0; } static int synthesize_name_acquired(sd_bus *a, sd_bus *b, sd_bus_message *m) { _cleanup_bus_message_unref_ sd_bus_message *n = NULL; const char *name, *old_owner, *new_owner; int r; assert(a); assert(b); assert(m); /* If we get NameOwnerChanged for our own name, we need to * synthesize NameLost/NameAcquired, since socket clients need * that, even though it is obsoleted on kdbus */ if (!a->is_kernel) return 0; if (!sd_bus_message_is_signal(m, "org.freedesktop.DBus", "NameOwnerChanged") || !streq_ptr(m->path, "/org/freedesktop/DBus") || !streq_ptr(m->sender, "org.freedesktop.DBus")) return 0; r = sd_bus_message_read(m, "sss", &name, &old_owner, &new_owner); if (r < 0) return r; r = sd_bus_message_rewind(m, true); if (r < 0) return r; if (streq(old_owner, a->unique_name)) { r = sd_bus_message_new_signal( b, "/org/freedesktop/DBus", "org.freedesktop.DBus", "NameLost", &n); } else if (streq(new_owner, a->unique_name)) { r = sd_bus_message_new_signal( b, "/org/freedesktop/DBus", "org.freedesktop.DBus", "NameAcquired", &n); } else return 0; if (r < 0) return r; r = sd_bus_message_append(n, "s", name); if (r < 0) return r; r = bus_message_append_sender(n, "org.freedesktop.DBus"); if (r < 0) return r; r = bus_seal_synthetic_message(b, n); if (r < 0) return r; return sd_bus_send(b, n, NULL); } static int process_policy(sd_bus *a, sd_bus *b, sd_bus_message *m) { _cleanup_bus_message_unref_ sd_bus_message *n = NULL; int r; assert(a); assert(b); assert(m); if (!sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Properties", "GetAll")) return 0; if (!streq_ptr(m->path, "/org/gnome/DisplayManager/Slave")) return 0; r = sd_bus_message_new_method_errorf(m, &n, SD_BUS_ERROR_ACCESS_DENIED, "gdm, you are stupid"); if (r < 0) return r; r = bus_message_append_sender(n, "org.freedesktop.DBus"); if (r < 0) { log_error("Failed to append sender to gdm reply: %s", strerror(-r)); return r; } r = bus_seal_synthetic_message(b, n); if (r < 0) { log_error("Failed to seal gdm reply: %s", strerror(-r)); return r; } r = sd_bus_send(b, n, NULL); if (r < 0) { log_error("Failed to send gdm reply: %s", strerror(-r)); return r; } return 1; } static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hello) { _cleanup_bus_message_unref_ sd_bus_message *n = NULL; bool is_hello; int r; assert(a); assert(b); assert(m); assert(got_hello); /* As reaction to hello we need to respond with two messages: * the callback reply and the NameAcquired for the unique * name, since hello is otherwise obsolete on kdbus. */ is_hello = sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "Hello") && streq_ptr(m->destination, "org.freedesktop.DBus"); if (!is_hello) { if (*got_hello) return 0; log_error("First packet isn't hello (it's %s.%s), aborting.", m->interface, m->member); return -EIO; } if (*got_hello) { log_error("Got duplicate hello, aborting."); return -EIO; } *got_hello = true; if (!a->is_kernel) return 0; r = sd_bus_message_new_method_return(m, &n); if (r < 0) { log_error("Failed to generate HELLO reply: %s", strerror(-r)); return r; } r = sd_bus_message_append(n, "s", a->unique_name); if (r < 0) { log_error("Failed to append unique name to HELLO reply: %s", strerror(-r)); return r; } r = bus_message_append_sender(n, "org.freedesktop.DBus"); if (r < 0) { log_error("Failed to append sender to HELLO reply: %s", strerror(-r)); return r; } r = bus_seal_synthetic_message(b, n); if (r < 0) { log_error("Failed to seal HELLO reply: %s", strerror(-r)); return r; } r = sd_bus_send(b, n, NULL); if (r < 0) { log_error("Failed to send HELLO reply: %s", strerror(-r)); return r; } n = sd_bus_message_unref(n); r = sd_bus_message_new_signal( b, "/org/freedesktop/DBus", "org.freedesktop.DBus", "NameAcquired", &n); if (r < 0) { log_error("Failed to allocate initial NameAcquired message: %s", strerror(-r)); return r; } r = sd_bus_message_append(n, "s", a->unique_name); if (r < 0) { log_error("Failed to append unique name to NameAcquired message: %s", strerror(-r)); return r; } r = bus_message_append_sender(n, "org.freedesktop.DBus"); if (r < 0) { log_error("Failed to append sender to NameAcquired message: %s", strerror(-r)); return r; } r = bus_seal_synthetic_message(b, n); if (r < 0) { log_error("Failed to seal NameAcquired message: %s", strerror(-r)); return r; } r = sd_bus_send(b, n, NULL); if (r < 0) { log_error("Failed to send NameAcquired message: %s", strerror(-r)); return r; } return 1; } int main(int argc, char *argv[]) { _cleanup_bus_unref_ sd_bus *a = NULL, *b = NULL; sd_id128_t server_id; int r, in_fd, out_fd; bool got_hello = false; bool is_unix; struct ucred ucred = {}; _cleanup_free_ char *peersec = NULL; log_set_target(LOG_TARGET_JOURNAL_OR_KMSG); log_parse_environment(); log_open(); r = parse_argv(argc, argv); if (r <= 0) goto finish; r = sd_listen_fds(0); if (r == 0) { in_fd = STDIN_FILENO; out_fd = STDOUT_FILENO; } else if (r == 1) { in_fd = SD_LISTEN_FDS_START; out_fd = SD_LISTEN_FDS_START; } else { log_error("Illegal number of file descriptors passed"); goto finish; } is_unix = sd_is_socket(in_fd, AF_UNIX, 0, 0) > 0 && sd_is_socket(out_fd, AF_UNIX, 0, 0) > 0; if (is_unix) { getpeercred(in_fd, &ucred); getpeersec(in_fd, &peersec); } r = sd_bus_new(&a); if (r < 0) { log_error("Failed to allocate bus: %s", strerror(-r)); goto finish; } r = sd_bus_set_address(a, arg_address); if (r < 0) { log_error("Failed to set address to connect to: %s", strerror(-r)); goto finish; } r = sd_bus_negotiate_fds(a, is_unix); if (r < 0) { log_error("Failed to set FD negotiation: %s", strerror(-r)); goto finish; } if (ucred.pid > 0) { a->fake_creds.pid = ucred.pid; a->fake_creds.uid = ucred.uid; a->fake_creds.gid = ucred.gid; a->fake_creds_valid = true; } if (peersec) { a->fake_label = peersec; peersec = NULL; } a->manual_peer_interface = true; r = sd_bus_start(a); if (r < 0) { log_error("Failed to start bus client: %s", strerror(-r)); goto finish; } r = sd_bus_get_server_id(a, &server_id); if (r < 0) { log_error("Failed to get server ID: %s", strerror(-r)); goto finish; } r = sd_bus_new(&b); if (r < 0) { log_error("Failed to allocate bus: %s", strerror(-r)); goto finish; } r = sd_bus_set_fd(b, in_fd, out_fd); if (r < 0) { log_error("Failed to set fds: %s", strerror(-r)); goto finish; } r = sd_bus_set_server(b, 1, server_id); if (r < 0) { log_error("Failed to set server mode: %s", strerror(-r)); goto finish; } r = sd_bus_negotiate_fds(b, is_unix); if (r < 0) { log_error("Failed to set FD negotiation: %s", strerror(-r)); goto finish; } r = sd_bus_set_anonymous(b, true); if (r < 0) { log_error("Failed to set anonymous authentication: %s", strerror(-r)); goto finish; } b->manual_peer_interface = true; r = sd_bus_start(b); if (r < 0) { log_error("Failed to start bus client: %s", strerror(-r)); goto finish; } r = rename_service(a, b); if (r < 0) log_debug("Failed to rename process: %s", strerror(-r)); if (a->is_kernel) { _cleanup_free_ char *match = NULL; const char *unique; r = sd_bus_get_unique_name(a, &unique); if (r < 0) { log_error("Failed to get unique name: %s", strerror(-r)); goto finish; } match = strjoin("type='signal'," "sender='org.freedesktop.DBus'," "path='/org/freedesktop/DBus'," "interface='org.freedesktop.DBus'," "member='NameOwnerChanged'," "arg1='", unique, "'", NULL); if (!match) { log_oom(); goto finish; } r = sd_bus_add_match(a, match, NULL, NULL); if (r < 0) { log_error("Failed to add match for NameLost: %s", strerror(-r)); goto finish; } free(match); match = strjoin("type='signal'," "sender='org.freedesktop.DBus'," "path='/org/freedesktop/DBus'," "interface='org.freedesktop.DBus'," "member='NameOwnerChanged'," "arg2='", unique, "'", NULL); if (!match) { log_oom(); goto finish; } r = sd_bus_add_match(a, match, NULL, NULL); if (r < 0) { log_error("Failed to add match for NameAcquired: %s", strerror(-r)); goto finish; } } for (;;) { _cleanup_bus_message_unref_ sd_bus_message *m = NULL; int events_a, events_b, fd; uint64_t timeout_a, timeout_b, t; struct timespec _ts, *ts; struct pollfd *pollfd; int k; if (got_hello) { r = sd_bus_process(a, &m); if (r < 0) { /* treat 'connection reset by peer' as clean exit condition */ if (r == -ECONNRESET) r = 0; else log_error("Failed to process bus a: %s", strerror(-r)); goto finish; } if (m) { /* We officially got EOF, let's quit */ if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) { r = 0; goto finish; } k = synthesize_name_acquired(a, b, m); if (k < 0) { r = k; log_error("Failed to synthesize message: %s", strerror(-r)); goto finish; } k = sd_bus_send(b, m, NULL); if (k < 0) { r = k; log_error("Failed to send message: %s", strerror(-r)); goto finish; } } if (r > 0) continue; } r = sd_bus_process(b, &m); if (r < 0) { /* treat 'connection reset by peer' as clean exit condition */ if (r == -ECONNRESET) r = 0; else log_error("Failed to process bus b: %s", strerror(-r)); goto finish; } if (m) { /* We officially got EOF, let's quit */ if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) { r = 0; goto finish; } k = process_hello(a, b, m, &got_hello); if (k < 0) { r = k; goto finish; } if (k > 0) r = k; else { k = process_policy(a, b, m); if (k < 0) { r = k; goto finish; } k = sd_bus_send(a, m, NULL); if (k < 0) { r = k; log_error("Failed to send message: %s", strerror(-r)); goto finish; } } } if (r > 0) continue; fd = sd_bus_get_fd(a); if (fd < 0) { log_error("Failed to get fd: %s", strerror(-r)); goto finish; } events_a = sd_bus_get_events(a); if (events_a < 0) { log_error("Failed to get events mask: %s", strerror(-r)); goto finish; } r = sd_bus_get_timeout(a, &timeout_a); if (r < 0) { log_error("Failed to get timeout: %s", strerror(-r)); goto finish; } events_b = sd_bus_get_events(b); if (events_b < 0) { log_error("Failed to get events mask: %s", strerror(-r)); goto finish; } r = sd_bus_get_timeout(b, &timeout_b); if (r < 0) { log_error("Failed to get timeout: %s", strerror(-r)); goto finish; } t = timeout_a; if (t == (uint64_t) -1 || (timeout_b != (uint64_t) -1 && timeout_b < timeout_a)) t = timeout_b; if (t == (uint64_t) -1) ts = NULL; else { usec_t nw; nw = now(CLOCK_MONOTONIC); if (t > nw) t -= nw; else t = 0; ts = timespec_store(&_ts, t); } pollfd = (struct pollfd[3]) { {.fd = fd, .events = events_a, }, {.fd = in_fd, .events = events_b & POLLIN, }, {.fd = out_fd, .events = events_b & POLLOUT, } }; r = ppoll(pollfd, 3, ts, NULL); if (r < 0) { log_error("ppoll() failed: %m"); goto finish; } } r = 0; finish: sd_bus_flush(a); sd_bus_flush(b); return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }