/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include "sd-bus.h" #include "sd-daemon.h" #include "alloc-util.h" #include "build.h" #include "bus-internal.h" #include "bus-util.h" #include "errno-util.h" #include "io-util.h" #include "log.h" #include "main-func.h" #define DEFAULT_BUS_PATH "unix:path=/run/dbus/system_bus_socket" static const char *arg_bus_path = DEFAULT_BUS_PATH; static BusTransport arg_transport = BUS_TRANSPORT_LOCAL; static RuntimeScope arg_runtime_scope = RUNTIME_SCOPE_SYSTEM; static int help(void) { printf("%s [OPTIONS...]\n\n" "Forward messages between a pipe or socket and a D-Bus bus.\n\n" " -h --help Show this help\n" " --version Show package version\n" " -p --bus-path=PATH Path to the bus address (default: %s)\n" " --system Connect to system bus\n" " --user Connect to user bus\n" " -M --machine=CONTAINER Name of local container to connect to\n", program_invocation_short_name, DEFAULT_BUS_PATH); return 0; } static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_MACHINE, ARG_USER, ARG_SYSTEM, }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, ARG_VERSION }, { "bus-path", required_argument, NULL, 'p' }, { "user", no_argument, NULL, ARG_USER }, { "system", no_argument, NULL, ARG_SYSTEM }, { "machine", required_argument, NULL, 'M' }, {}, }; int c; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "hp:M:", options, NULL)) >= 0) switch (c) { case 'h': return help(); case ARG_VERSION: return version(); case ARG_USER: arg_runtime_scope = RUNTIME_SCOPE_USER; break; case ARG_SYSTEM: arg_runtime_scope = RUNTIME_SCOPE_SYSTEM; break; case 'p': arg_bus_path = optarg; break; case 'M': arg_bus_path = optarg; arg_transport = BUS_TRANSPORT_MACHINE; break; case '?': return -EINVAL; default: return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown option code %c", c); } return 1; } static int run(int argc, char *argv[]) { _cleanup_(sd_bus_flush_close_unrefp) sd_bus *a = NULL, *b = NULL; sd_id128_t server_id; bool is_unix; int r, in_fd, out_fd; log_set_target(LOG_TARGET_JOURNAL_OR_KMSG); log_parse_environment(); log_open(); r = parse_argv(argc, argv); if (r <= 0) return r; 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 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "More than one file descriptor was passed."); is_unix = sd_is_socket(in_fd, AF_UNIX, 0, 0) > 0 && sd_is_socket(out_fd, AF_UNIX, 0, 0) > 0; r = sd_bus_new(&a); if (r < 0) return log_error_errno(r, "Failed to allocate bus: %m"); if (arg_transport == BUS_TRANSPORT_MACHINE) r = bus_set_address_machine(a, arg_runtime_scope, arg_bus_path); else r = sd_bus_set_address(a, arg_bus_path); if (r < 0) return log_error_errno(r, "Failed to set address to connect to: %m"); r = sd_bus_negotiate_fds(a, is_unix); if (r < 0) return log_error_errno(r, "Failed to set FD negotiation: %m"); r = sd_bus_start(a); if (r < 0) return log_error_errno(r, "Failed to start bus client: %m"); r = sd_bus_get_bus_id(a, &server_id); if (r < 0) return log_error_errno(r, "Failed to get server ID: %m"); r = sd_bus_new(&b); if (r < 0) return log_error_errno(r, "Failed to allocate bus: %m"); r = sd_bus_set_fd(b, in_fd, out_fd); if (r < 0) return log_error_errno(r, "Failed to set fds: %m"); r = sd_bus_set_server(b, 1, server_id); if (r < 0) return log_error_errno(r, "Failed to set server mode: %m"); r = sd_bus_negotiate_fds(b, is_unix); if (r < 0) return log_error_errno(r, "Failed to set FD negotiation: %m"); r = sd_bus_set_anonymous(b, true); if (r < 0) return log_error_errno(r, "Failed to set anonymous authentication: %m"); r = sd_bus_start(b); if (r < 0) return log_error_errno(r, "Failed to start bus client: %m"); for (;;) { _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; int events_a, events_b, fd; usec_t timeout_a, timeout_b, t; assert_cc(sizeof(usec_t) == sizeof(uint64_t)); r = sd_bus_process(a, &m); if (ERRNO_IS_NEG_DISCONNECT(r)) /* Treat 'connection reset by peer' as clean exit condition */ return 0; if (r < 0) return log_error_errno(r, "Failed to process bus a: %m"); if (m) { if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) return 0; r = sd_bus_send(b, m, NULL); if (r < 0) return log_error_errno(r, "Failed to send message: %m"); } if (r > 0) continue; r = sd_bus_process(b, &m); if (ERRNO_IS_NEG_DISCONNECT(r)) /* Treat 'connection reset by peer' as clean exit condition */ return 0; if (r < 0) return log_error_errno(r, "Failed to process bus: %m"); if (m) { if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) return 0; r = sd_bus_send(a, m, NULL); if (r < 0) return log_error_errno(r, "Failed to send message: %m"); } if (r > 0) continue; fd = sd_bus_get_fd(a); if (fd < 0) return log_error_errno(fd, "Failed to get fd: %m"); events_a = sd_bus_get_events(a); if (events_a < 0) return log_error_errno(events_a, "Failed to get events mask: %m"); r = sd_bus_get_timeout(a, &timeout_a); if (r < 0) return log_error_errno(r, "Failed to get timeout: %m"); events_b = sd_bus_get_events(b); if (events_b < 0) return log_error_errno(events_b, "Failed to get events mask: %m"); r = sd_bus_get_timeout(b, &timeout_b); if (r < 0) return log_error_errno(r, "Failed to get timeout: %m"); t = usec_sub_unsigned(MIN(timeout_a, timeout_b), now(CLOCK_MONOTONIC)); struct pollfd p[3] = { { .fd = fd, .events = events_a }, { .fd = in_fd, .events = events_b & POLLIN }, { .fd = out_fd, .events = events_b & POLLOUT }, }; r = ppoll_usec(p, ELEMENTSOF(p), t); if (r < 0 && !ERRNO_IS_TRANSIENT(r)) /* don't be bothered by signals, i.e. EINTR */ return log_error_errno(r, "ppoll() failed: %m"); } } DEFINE_MAIN_FUNCTION(run);