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-rw-r--r--src/stdio-bridge/stdio-bridge.c259
1 files changed, 259 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..81d5071
--- /dev/null
+++ b/src/stdio-bridge/stdio-bridge.c
@@ -0,0 +1,259 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <getopt.h>
+#include <poll.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 "log.h"
+#include "main-func.h"
+#include "util.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 int help(void) {
+
+ printf("%s [OPTIONS...]\n\n"
+ "STDIO or socket-activatable proxy to a given DBus endpoint.\n\n"
+ " -h --help Show this help\n"
+ " --version Show package version\n"
+ " -p --bus-path=PATH Path to the kernel bus (default: %s)\n"
+ " -M --machine=MACHINE Name of machine 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,
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ { "bus-path", required_argument, NULL, 'p' },
+ { "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 '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), "Illegal number of file descriptors 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_system_machine(a, 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;
+ uint64_t timeout_a, timeout_b, t;
+ struct timespec _ts, *ts;
+
+ r = sd_bus_process(a, &m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to process bus a: %m");
+
+ if (m) {
+ 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 (r < 0) {
+ /* treat 'connection reset by peer' as clean exit condition */
+ if (ERRNO_IS_DISCONNECT(r))
+ return 0;
+
+ return log_error_errno(r, "Failed to process bus: %m");
+ }
+
+ if (m) {
+ 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 = 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);
+ }
+
+ 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(p, ELEMENTSOF(p), ts, NULL);
+ if (r < 0)
+ return log_error_errno(errno, "ppoll() failed: %m");
+ if (p[0].revents & POLLNVAL ||
+ p[1].revents & POLLNVAL ||
+ p[2].revents & POLLNVAL)
+ return log_error_errno(SYNTHETIC_ERRNO(EBADF), "Invalid file descriptor to poll on?");
+ }
+
+ return 0;
+}
+
+DEFINE_MAIN_FUNCTION(run);
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