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=debaab2a2e66d98e051b7f92fdc39781fdbc308d;hp=ab9b836ff0730a6f437aabc5c954ff4faff0af86;hb=c0395aeb903cde25bd9e81fba3334f63335fe0ef;hpb=7b217f41d2e31330b47aeaadbd3bf93c9eb1ce46 diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c index ab9b836ff..debaab2a2 100644 --- a/src/bus-proxyd/bus-proxyd.c +++ b/src/bus-proxyd/bus-proxyd.c @@ -4,6 +4,8 @@ This file is part of systemd. Copyright 2010 Lennart Poettering + Copyright 2013 Daniel Mack + Copyright 2014 Kay Sievers systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by @@ -41,18 +43,31 @@ #include "build.h" #include "strv.h" #include "def.h" - -static const char *arg_address = DEFAULT_SYSTEM_BUS_PATH; +#include "capability.h" +#include "bus-control.h" +#include "smack-util.h" +#include "set.h" +#include "bus-xml-policy.h" +#include "driver.h" +#include "proxy.h" +#include "synthesize.h" + +static char *arg_address = NULL; static char *arg_command_line_buffer = NULL; +static bool arg_drop_privileges = false; +static char **arg_configuration = NULL; static int help(void) { printf("%s [OPTIONS...]\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" - " --address=ADDRESS Connect to the bus specified by ADDRESS\n" - " (default: " DEFAULT_SYSTEM_BUS_PATH ")\n", + " -h --help Show this help\n" + " --version Show package version\n" + " --drop-privileges Drop privileges\n" + " --configuration=PATH Configuration file or directory\n" + " --machine=MACHINE Connect to specified machine\n" + " --address=ADDRESS Connect to the bus specified by ADDRESS\n" + " (default: " DEFAULT_SYSTEM_BUS_ADDRESS ")\n", program_invocation_short_name); return 0; @@ -63,21 +78,27 @@ static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_ADDRESS, + ARG_DROP_PRIVILEGES, + ARG_CONFIGURATION, + ARG_MACHINE, }; static const struct option options[] = { - { "help", no_argument, NULL, 'h' }, - { "version", no_argument, NULL, ARG_VERSION }, - { "address", required_argument, NULL, ARG_ADDRESS }, - { NULL, 0, NULL, 0 } + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "address", required_argument, NULL, ARG_ADDRESS }, + { "drop-privileges", no_argument, NULL, ARG_DROP_PRIVILEGES }, + { "configuration", required_argument, NULL, ARG_CONFIGURATION }, + { "machine", required_argument, NULL, ARG_MACHINE }, + {}, }; - int c; + int c, r; assert(argc >= 0); assert(argv); - while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { + while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) switch (c) { @@ -90,28 +111,72 @@ static int parse_argv(int argc, char *argv[]) { puts(SYSTEMD_FEATURES); return 0; - case ARG_ADDRESS: - arg_address = optarg; + case ARG_ADDRESS: { + char *a; + + a = strdup(optarg); + if (!a) + return log_oom(); + + free(arg_address); + arg_address = a; + break; + } + + case ARG_DROP_PRIVILEGES: + arg_drop_privileges = true; + break; + + case ARG_CONFIGURATION: + r = strv_extend(&arg_configuration, optarg); + if (r < 0) + return log_oom(); break; + case ARG_MACHINE: { + _cleanup_free_ char *e = NULL; + char *a; + + e = bus_address_escape(optarg); + if (!e) + return log_oom(); + +#ifdef ENABLE_KDBUS + a = strjoin("x-machine-kernel:machine=", e, ";x-machine-unix:machine=", e, NULL); +#else + a = strjoin("x-machine-unix:machine=", e, NULL); +#endif + if (!a) + return log_oom(); + + free(arg_address); + arg_address = a; + + break; + } + case '?': return -EINVAL; default: 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)) { + if (argc > optind + 1 || (arg_command_line_buffer && !in_charset(arg_command_line_buffer, "x"))) { log_error("Too many arguments"); return -EINVAL; } + if (!arg_address) { + arg_address = strdup(DEFAULT_SYSTEM_BUS_ADDRESS); + if (!arg_address) + return log_oom(); + } + return 1; } @@ -127,7 +192,7 @@ static int rename_service(sd_bus *a, sd_bus *b) { 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); + r = sd_bus_get_owner_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM|SD_BUS_CREDS_AUGMENT, &creds); if (r < 0) return r; @@ -172,268 +237,21 @@ static int rename_service(sd_bus *a, sd_bus *b) { uid, name); if (m > w) - memset(arg_command_line_buffer + w, 0, m - w); + memzero(arg_command_line_buffer + w, m - w); } log_debug("Running on behalf of PID "PID_FMT" (%s), UID "UID_FMT" (%s), %s", pid, p, 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; -} - -static int patch_sender(sd_bus *a, sd_bus_message *m) { - char **well_known = NULL; - sd_bus_creds *c; - int r; - - assert(a); - assert(m); - - if (!a->is_kernel) - return 0; - - /* We will change the sender of messages from the bus driver - * so that they originate from the bus driver. This is a - * speciality originating from dbus1, where the bus driver did - * not have a unique id, but only the well-known name. */ - - c = sd_bus_message_get_creds(m); - if (!c) - return 0; - - r = sd_bus_creds_get_well_known_names(c, &well_known); - if (r < 0) - return r; - - if (strv_contains(well_known, "org.freedesktop.DBus")) - m->sender = "org.freedesktop.DBus"; return 0; } int main(int argc, char *argv[]) { - - _cleanup_bus_unref_ sd_bus *a = NULL, *b = NULL; - sd_id128_t server_id; + _cleanup_(proxy_freep) Proxy *p = NULL; int r, in_fd, out_fd; - bool got_hello = false; - bool is_unix; - struct ucred ucred = {}; - _cleanup_free_ char *peersec = NULL; + uid_t original_uid; log_set_target(LOG_TARGET_JOURNAL_OR_KMSG); log_parse_environment(); @@ -455,330 +273,49 @@ int main(int argc, char *argv[]) { goto finish; } - is_unix = - 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; - } + original_uid = getuid(); - r = sd_bus_set_name(a, "sd-proxy"); - if (r < 0) { - log_error("Failed to set bus name: %s", strerror(-r)); - goto finish; - } - - 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; - } - - r = sd_bus_negotiate_fds(a, is_unix); - if (r < 0) { - log_error("Failed to set FD negotiation: %s", strerror(-r)); - goto finish; - } + if (arg_drop_privileges) { + const char *user = "systemd-bus-proxy"; + uid_t uid; + gid_t gid; - 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)); - goto finish; - } - - r = sd_bus_get_server_id(a, &server_id); - if (r < 0) { - log_error("Failed to get server ID: %s", strerror(-r)); - goto finish; - } - - r = sd_bus_new(&b); - if (r < 0) { - log_error("Failed to allocate bus: %s", strerror(-r)); - goto finish; - } - - r = sd_bus_set_fd(b, in_fd, out_fd); - if (r < 0) { - log_error("Failed to set fds: %s", strerror(-r)); - goto finish; - } - - r = sd_bus_set_server(b, 1, server_id); - if (r < 0) { - log_error("Failed to set server mode: %s", strerror(-r)); - goto finish; - } - - r = sd_bus_negotiate_fds(b, is_unix); - if (r < 0) { - log_error("Failed to set FD negotiation: %s", strerror(-r)); - goto finish; - } - - r = sd_bus_set_anonymous(b, true); - if (r < 0) { - log_error("Failed to set anonymous authentication: %s", strerror(-r)); - 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; - } - - 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; - - r = sd_bus_get_unique_name(a, &unique); + r = get_user_creds(&user, &uid, &gid, NULL, NULL); if (r < 0) { - log_error("Failed to get unique name: %s", strerror(-r)); + log_error_errno(r, "Cannot resolve user name %s: %m", user); 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)); + r = drop_privileges(uid, gid, 1ULL << CAP_IPC_OWNER); + if (r < 0) 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; - - 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 = synthesize_name_acquired(a, b, m); - if (k < 0) { - r = k; - log_error("Failed to synthesize message: %s", strerror(-r)); - goto finish; - } - - patch_sender(a, m); - - k = sd_bus_send(b, m, NULL); - if (k < 0) { - if (k == -ECONNRESET) - r = 0; - else { - 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) { - /* 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; - log_error("Failed to process HELLO: %s", strerror(-r)); - goto finish; - } - - if (k > 0) - r = k; - else { - k = process_policy(a, b, m); - if (k < 0) { - r = k; - log_error("Failed to process policy: %s", strerror(-r)); - goto finish; - } - - k = sd_bus_send(a, m, NULL); - if (k < 0) { - if (r == -ECONNRESET) - r = 0; - else { - r = k; - log_error("Failed to send message: %s", strerror(-r)); - } - - goto finish; - } - } - } - - if (r > 0) - continue; - - fd = sd_bus_get_fd(a); - if (fd < 0) { - log_error("Failed to get fd: %s", strerror(-r)); - 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; - } - - r = sd_bus_get_timeout(b, &timeout_b); - 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; - - if (t == (uint64_t) -1) - ts = NULL; - else { - usec_t nw; - - nw = now(CLOCK_MONOTONIC); - if (t > nw) - t -= nw; - else - t = 0; + r = proxy_new(&p, in_fd, out_fd, arg_address); + if (r < 0) + goto finish; - ts = timespec_store(&_ts, t); - } + r = proxy_load_policy(p, arg_configuration); + if (r < 0) + goto finish; - pollfd = (struct pollfd[3]) { - {.fd = fd, .events = events_a, }, - {.fd = in_fd, .events = events_b & POLLIN, }, - {.fd = out_fd, .events = events_b & POLLOUT, } - }; + r = proxy_hello_policy(p, original_uid); + if (r < 0) + goto finish; - r = ppoll(pollfd, 3, ts, NULL); - if (r < 0) { - log_error("ppoll() failed: %m"); - goto finish; - } - } + r = rename_service(p->dest_bus, p->local_bus); + if (r < 0) + log_debug_errno(r, "Failed to rename process: %m"); - r = 0; + r = proxy_run(p); finish: - sd_bus_flush(a); - sd_bus_flush(b); + sd_notify(false, + "STOPPING=1\n" + "STATUS=Shutting down."); + + strv_free(arg_configuration); + free(arg_address); return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }