X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbus-proxyd%2Fbus-proxyd.c;h=c4da8d6d7f26493b9fc4efebb55bb585094019aa;hp=f391fbf42bec3b178968842adb07a634724858d3;hb=9f6445e34a57c270f013c9416c123e56261553dd;hpb=683fc3a4480645fd2201e5f7c2e1fee277b3eaa0 diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c index f391fbf42..c4da8d6d7 100644 --- a/src/bus-proxyd/bus-proxyd.c +++ b/src/bus-proxyd/bus-proxyd.c @@ -39,19 +39,29 @@ #include "bus-message.h" #include "bus-util.h" #include "build.h" +#include "strv.h" -#define DEFAULT_BUS_PATH "unix:path=/run/dbus/system_bus_socket" +#define UNIX_BUS_PATH "unix:path=/run/dbus/system_bus_socket" +#define KERNEL_BUS_PATH "kernel:path=/dev/kdbus/0-system/bus" -const char *arg_bus_path = DEFAULT_BUS_PATH; +#ifdef ENABLE_KDBUS +# define DEFAULT_BUS_PATH KERNEL_BUS_PATH ";" UNIX_BUS_PATH +#else +# 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" - "STDIO or socket-activatable proxy to a given DBus endpoint.\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 Path to the kernel bus (default: %s)\n", - program_invocation_short_name, DEFAULT_BUS_PATH); + " --address=ADDRESS Connect to the bus specified by ADDRESS\n" + " (default: " DEFAULT_BUS_PATH ")\n", + program_invocation_short_name); return 0; } @@ -60,12 +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; @@ -73,7 +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) { @@ -86,27 +98,275 @@ 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; +} + +static int rename_service(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(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); + } + + 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_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; - bool is_unix; 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(); @@ -124,7 +384,7 @@ int main(int argc, char *argv[]) { in_fd = SD_LISTEN_FDS_START; out_fd = SD_LISTEN_FDS_START; } else { - log_error("Illegal number of file descriptors passed\n"); + log_error("Illegal number of file descriptors passed"); goto finish; } @@ -132,13 +392,18 @@ int main(int argc, char *argv[]) { 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_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; @@ -150,6 +415,18 @@ int main(int argc, char *argv[]) { 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; + } + r = sd_bus_start(a); if (r < 0) { log_error("Failed to start bus client: %s", strerror(-r)); @@ -198,44 +475,142 @@ int main(int argc, char *argv[]) { goto finish; } + r = rename_service(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; - r = sd_bus_process(a, &m); - if (r < 0) { - log_error("Failed to process bus a: %s", strerror(-r)); - goto finish; - } - - if (m) { - r = sd_bus_send(b, m, NULL); + if (got_hello) { + r = sd_bus_process(a, &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 a: %s", 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 = 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) { - r = sd_bus_send(a, m, NULL); - if (r < 0) { - log_error("Failed to send message: %s", strerror(-r)); + /* 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 = 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) @@ -289,14 +664,13 @@ 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 = events_a, }, + {.fd = in_fd, .events = events_b & POLLIN, }, + {.fd = out_fd, .events = events_b & POLLOUT, } + }; - r = ppoll(p, ELEMENTSOF(p), ts, NULL); - } + r = ppoll(pollfd, 3, ts, NULL); if (r < 0) { log_error("ppoll() failed: %m"); goto finish; @@ -306,5 +680,8 @@ int main(int argc, char *argv[]) { r = 0; finish: + sd_bus_flush(a); + sd_bus_flush(b); + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }