diff options
Diffstat (limited to 'src/stdio-bridge/stdio-bridge.c')
| -rw-r--r-- | src/stdio-bridge/stdio-bridge.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/src/stdio-bridge/stdio-bridge.c b/src/stdio-bridge/stdio-bridge.c new file mode 100644 index 0000000..fe551cf --- /dev/null +++ b/src/stdio-bridge/stdio-bridge.c @@ -0,0 +1,252 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <getopt.h> +#include <stddef.h> +#include <string.h> +#include <unistd.h> + +#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 = STDIN_FILENO, .events = events_b & POLLIN }, + { .fd = STDOUT_FILENO, .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); |