X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbus-proxyd%2Fbus-proxyd.c;h=28e8b44ccd499a26e4e6daf2a9056c0d520f6052;hp=91472d93f1976aea0c26bb839a39626207596a71;hb=ab9001a1e3dc6e60d0cdf53363dc5d18dcc382fd;hpb=b2bb3469fd01cec57f1f1726edb5b851ff8427ad diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c index 91472d93f..28e8b44cc 100644 --- a/src/bus-proxyd/bus-proxyd.c +++ b/src/bus-proxyd/bus-proxyd.c @@ -40,13 +40,9 @@ #include "bus-util.h" #include "build.h" #include "strv.h" +#include "def.h" -#ifdef ENABLE_KDBUS -static const char *arg_address = "kernel:path=/dev/kdbus/0-system/bus;unix:path=/run/dbus/system_bus_socket"; -#else -static const char *arg_address = "unix:path=/run/dbus/system_bus_socket"; -#endif - +static const char *arg_address = DEFAULT_SYSTEM_BUS_PATH; static char *arg_command_line_buffer = NULL; static int help(void) { @@ -55,7 +51,8 @@ static int help(void) { "Connect STDIO or a socket to a given bus address.\n\n" " -h --help Show this help\n" " --version Show package version\n" - " --address=ADDRESS Connect to bus specified by address\n", + " --address=ADDRESS Connect to the bus specified by ADDRESS\n" + " (default: " DEFAULT_SYSTEM_BUS_PATH ")\n", program_invocation_short_name); return 0; @@ -80,7 +77,7 @@ 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) { @@ -118,17 +115,295 @@ static int parse_argv(int argc, char *argv[]) { return 1; } +static int rename_service(sd_bus *a, 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(a); + 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); + } + + log_debug("Running on behalf of PID %lu (%s), UID %lu (%s), %s", + (unsigned long) pid, p, + (unsigned long) uid, name, + a->unique_name); + ; + 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_policy(sd_bus *a, sd_bus *b, sd_bus_message *m) { + _cleanup_bus_message_unref_ sd_bus_message *n = NULL; + int r; + + assert(a); + assert(b); + assert(m); + + if (!sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Properties", "GetAll")) + return 0; + + if (!streq_ptr(m->path, "/org/gnome/DisplayManager/Slave")) + return 0; + + r = sd_bus_message_new_method_errorf(m, &n, SD_BUS_ERROR_ACCESS_DENIED, "gdm, you are stupid"); + if (r < 0) + return r; + + r = bus_message_append_sender(n, "org.freedesktop.DBus"); + if (r < 0) { + log_error("Failed to append sender to gdm reply: %s", strerror(-r)); + return r; + } + + r = bus_seal_synthetic_message(b, n); + if (r < 0) { + log_error("Failed to seal gdm reply: %s", strerror(-r)); + return r; + } + + r = sd_bus_send(b, n, NULL); + if (r < 0) { + log_error("Failed to send gdm reply: %s", strerror(-r)); + return r; + } + + return 1; +} + +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_creds_unref_ sd_bus_creds *creds = NULL; _cleanup_bus_unref_ sd_bus *a = NULL, *b = NULL; sd_id128_t server_id; int r, in_fd, out_fd; - char **cmdline; - const char *comm; + bool got_hello = false; bool is_unix; - uid_t uid; - pid_t pid; + struct ucred ucred = {}; + _cleanup_free_ char *peersec = NULL; log_set_target(LOG_TARGET_JOURNAL_OR_KMSG); log_parse_environment(); @@ -146,7 +421,7 @@ 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; } @@ -154,6 +429,11 @@ 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)); @@ -172,6 +452,20 @@ 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; + } + + a->manual_peer_interface = true; + r = sd_bus_start(a); if (r < 0) { log_error("Failed to start bus client: %s", strerror(-r)); @@ -214,50 +508,67 @@ int main(int argc, char *argv[]) { goto finish; } + b->manual_peer_interface = true; + r = sd_bus_start(b); if (r < 0) { log_error("Failed to start bus client: %s", strerror(-r)); goto finish; } - 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 = rename_service(a, 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; - name = uid_to_name(uid); - if (!name) { - r = log_oom(); + r = sd_bus_get_unique_name(a, &unique); + if (r < 0) { + log_error("Failed to get unique name: %s", strerror(-r)); goto finish; } - p = strv_join(cmdline, " "); - if (!p) { - r = log_oom(); + 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; } - /* 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); + 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; + } - if (m > w) - memset(arg_command_line_buffer + w, 0, m - w); + 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; } } @@ -269,34 +580,43 @@ int main(int argc, char *argv[]) { struct pollfd *pollfd; int k; - r = sd_bus_process(a, &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 a: %s", strerror(-r)); + if (got_hello) { + r = sd_bus_process(a, &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 a: %s", strerror(-r)); - goto finish; - } - - 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(b, m, NULL); - if (k < 0) { - r = k; - log_error("Failed to send message: %s", strerror(-r)); - goto finish; + 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; + if (r > 0) + continue; + } r = sd_bus_process(b, &m); if (r < 0) { @@ -316,12 +636,28 @@ int main(int argc, char *argv[]) { goto finish; } - k = sd_bus_send(a, m, NULL); + k = process_hello(a, b, m, &got_hello); if (k < 0) { r = k; - log_error("Failed to send message: %s", strerror(-r)); goto finish; } + + if (k > 0) + r = k; + else { + k = process_policy(a, b, m); + if (k < 0) { + r = k; + goto finish; + } + + 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)