chiark / gitweb /
man: add systemd-dbus-proxy@.service(8) and systemd-dbus.proxy(8)
[elogind.git] / src / bus-proxyd / bus-proxyd.c
index 015f40a65ce0ab5d5f14068e976d9c03159714f7..80d21203ed12f22fa6085d89b43c282b3511600d 100644 (file)
 #include "bus-message.h"
 #include "bus-util.h"
 #include "build.h"
+#include "strv.h"
+
+#define UNIX_BUS_PATH "unix:path=/run/dbus/system_bus_socket"
+#define KERNEL_BUS_PATH "kernel:path=/dev/kdbus/0-system/bus"
 
 #ifdef ENABLE_KDBUS
-const char *arg_bus_path = "kernel:path=/dev/kdbus/0-system/bus;unix:path=/run/dbus/system_bus_socket";
+#  define DEFAULT_BUS_PATH KERNEL_BUS_PATH ";" UNIX_BUS_PATH
 #else
-const char *arg_bus_path = "unix:path=/run/dbus/system_bus_socket";
+#  define DEFAULT_BUS_PATH UNIX_BUS_PATH
 #endif
 
+static const char *arg_address = DEFAULT_BUS_PATH;
+static char *arg_command_line_buffer = NULL;
+
 static int help(void) {
 
         printf("%s [OPTIONS...]\n\n"
-               "Connection STDIO or a socket to a given bus address.\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"
-               "  -p --bus-path=PATH     Bus address to forward to (default: %s)\n",
-               program_invocation_short_name, arg_bus_path);
+               "     --address=ADDRESS   Connect to the bus specified by ADDRESS\n"
+               "                         (default: " DEFAULT_BUS_PATH ")\n",
+               program_invocation_short_name);
 
         return 0;
 }
@@ -62,12 +70,14 @@ static int parse_argv(int argc, char *argv[]) {
 
         enum {
                 ARG_VERSION = 0x100,
+                ARG_ADDRESS,
         };
 
         static const struct option options[] = {
-                { "help",            no_argument,       NULL, 'h'     },
-                { "bus-path",        required_argument, NULL, 'p'     },
-                { NULL,              0,                 NULL, 0       }
+                { "help",       no_argument,       NULL, 'h'            },
+                { "version",    no_argument,       NULL, ARG_VERSION    },
+                { "address",    required_argument, NULL, ARG_ADDRESS    },
+                { NULL,         0,                 NULL, 0              }
         };
 
         int c;
@@ -75,7 +85,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 0);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "hsup:", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
 
                 switch (c) {
 
@@ -88,27 +98,42 @@ static int parse_argv(int argc, char *argv[]) {
                         puts(SYSTEMD_FEATURES);
                         return 0;
 
+                case ARG_ADDRESS:
+                        arg_address = optarg;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
-                case 'p':
-                        arg_bus_path = optarg;
-                        break;
-
                 default:
-                        log_error("Unknown option code %c", c);
-                        return -EINVAL;
+                        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;
 }
 
 int main(int argc, char *argv[]) {
+
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
         _cleanup_bus_unref_ sd_bus *a = NULL, *b = NULL;
         sd_id128_t server_id;
-        bool is_unix;
         int r, in_fd, out_fd;
+        char **cmdline;
+        const char *comm;
+        bool is_unix;
+        uid_t uid;
+        pid_t pid;
 
         log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
         log_parse_environment();
@@ -140,7 +165,7 @@ int main(int argc, char *argv[]) {
                 goto finish;
         }
 
-        r = sd_bus_set_address(a, arg_bus_path);
+        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;
@@ -200,48 +225,95 @@ int main(int argc, char *argv[]) {
                 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;
+        if (sd_bus_get_peer_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM, &creds) >= 0 &&
+            sd_bus_creds_get_uid(creds, &uid) >= 0 &&
+            sd_bus_creds_get_pid(creds, &pid) >= 0 &&
+            sd_bus_creds_get_cmdline(creds, &cmdline) >= 0 &&
+            sd_bus_creds_get_comm(creds, &comm) >= 0) {
+                _cleanup_free_ char *p = NULL, *name = NULL;
 
-                r = sd_bus_process(a, &m);
-                if (r < 0) {
-                        log_error("Failed to process bus a: %s", strerror(-r));
+                name = uid_to_name(uid);
+                if (!name) {
+                        r = log_oom();
                         goto finish;
                 }
 
-                if (m) {
-                        r = sd_bus_send(b, m, NULL);
-                        if (r < 0) {
-                                log_error("Failed to send message: %s", strerror(-r));
-                                goto finish;
-                        }
+                p = strv_join(cmdline, " ");
+                if (!p) {
+                        r = log_oom();
+                        goto finish;
                 }
 
-                if (r > 0)
-                        continue;
+                /* 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);
 
-                r = sd_bus_process(b, &m);
-                if (r < 0) {
-                        /* treat 'connection reset by peer' as clean exit condition */
-                        if (r == -ECONNRESET)
-                                r = 0;
+                /* ... 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);
 
-                        goto finish;
                 }
+        }
 
-                if (m) {
-                        r = sd_bus_send(a, m, NULL);
+        for (;;) {
+                _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+                uint64_t t;
+                struct timespec _ts, *ts;
+                struct pollfd *pollfd;
+                int k, i, fd;
+
+                struct bus_bus {
+                        sd_bus *bus;
+                        const char *name;
+                        int events;
+                        uint64_t timeout;
+                } busses[2] = {
+                        {a, "a"},
+                        {b, "b"},
+                };
+
+                for (i = 0; i < 2; i ++) {
+                        r = sd_bus_process(busses[i].bus, &m);
                         if (r < 0) {
-                                log_error("Failed to send message: %s", strerror(-r));
+                                /* treat 'connection reset by peer' as clean exit condition */
+                                if (r == -ECONNRESET)
+                                        r = 0;
+                                else
+                                        log_error("Failed to process bus %s: %s",
+                                                  busses[i].name, strerror(-r));
                                 goto finish;
                         }
-                }
 
-                if (r > 0)
-                        continue;
+                        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 = sd_bus_send(busses[1-i].bus, m, NULL);
+                                if (k < 0) {
+                                        r = k;
+                                        log_error("Failed to send message to bus %s: %s",
+                                                  busses[1-i].name, strerror(-r));
+                                        goto finish;
+                                }
+                        }
+
+                        if (r > 0)
+                                continue;
+                }
 
                 fd = sd_bus_get_fd(a);
                 if (fd < 0) {
@@ -249,33 +321,24 @@ int main(int argc, char *argv[]) {
                         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;
-                }
+                for (i = 0; i < 2; i ++) {
+                        busses[i].events = sd_bus_get_events(a);
+                        if (busses[i].events < 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;
+                        r = sd_bus_get_timeout(a, &busses[i].timeout);
+                        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;
+                t = busses[0].timeout;
+                if (t == (uint64_t) -1 ||
+                    (busses[1].timeout != (uint64_t) -1 && busses[1].timeout < t))
+                        t = busses[1].timeout;
 
                 if (t == (uint64_t) -1)
                         ts = NULL;
@@ -291,14 +354,13 @@ int main(int argc, char *argv[]) {
                         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, }};
+                pollfd = (struct pollfd[3]) {
+                        {.fd = fd,     .events = busses[0].events           },
+                        {.fd = in_fd,  .events = busses[1].events & POLLIN  },
+                        {.fd = out_fd, .events = busses[1].events & POLLOUT },
+                };
 
-                        r = ppoll(p, ELEMENTSOF(p), ts, NULL);
-                }
+                r = ppoll(pollfd, 3, ts, NULL);
                 if (r < 0) {
                         log_error("ppoll() failed: %m");
                         goto finish;
@@ -308,5 +370,8 @@ int main(int argc, char *argv[]) {
         r = 0;
 
 finish:
+        sd_bus_flush(a);
+        sd_bus_flush(b);
+
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }