| /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| |
| /*** |
| This file is part of systemd. |
| |
| Copyright 2010 Lennart Poettering |
| Copyright 2013 Daniel Mack |
| Copyright 2014 Kay Sievers |
| Copyright 2014 David Herrmann |
| |
| 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 |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <poll.h> |
| |
| #include "log.h" |
| #include "util.h" |
| #include "sd-daemon.h" |
| #include "sd-bus.h" |
| #include "bus-internal.h" |
| #include "bus-message.h" |
| #include "bus-util.h" |
| #include "strv.h" |
| #include "bus-control.h" |
| #include "set.h" |
| #include "bus-xml-policy.h" |
| #include "driver.h" |
| #include "proxy.h" |
| #include "synthesize.h" |
| #include "formats-util.h" |
| |
| static int proxy_create_destination(Proxy *p, const char *destination, const char *local_sec, bool negotiate_fds) { |
| _cleanup_bus_flush_close_unref_ sd_bus *b = NULL; |
| int r; |
| |
| r = sd_bus_new(&b); |
| if (r < 0) |
| return log_error_errno(r, "Failed to allocate bus: %m"); |
| |
| r = sd_bus_set_description(b, "sd-proxy"); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set bus name: %m"); |
| |
| r = sd_bus_set_address(b, destination); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set address to connect to: %m"); |
| |
| r = sd_bus_negotiate_fds(b, negotiate_fds); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set FD negotiation: %m"); |
| |
| r = sd_bus_negotiate_creds(b, true, SD_BUS_CREDS_EUID|SD_BUS_CREDS_PID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SELINUX_CONTEXT); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set credential negotiation: %m"); |
| |
| if (p->local_creds.pid > 0) { |
| b->fake_pids.pid = p->local_creds.pid; |
| b->fake_pids_valid = true; |
| |
| b->fake_creds.uid = UID_INVALID; |
| b->fake_creds.euid = p->local_creds.uid; |
| b->fake_creds.suid = UID_INVALID; |
| b->fake_creds.fsuid = UID_INVALID; |
| b->fake_creds.gid = GID_INVALID; |
| b->fake_creds.egid = p->local_creds.gid; |
| b->fake_creds.sgid = GID_INVALID; |
| b->fake_creds.fsgid = GID_INVALID; |
| b->fake_creds_valid = true; |
| } |
| |
| if (local_sec) { |
| b->fake_label = strdup(local_sec); |
| if (!b->fake_label) |
| return log_oom(); |
| } |
| |
| b->manual_peer_interface = true; |
| |
| r = sd_bus_start(b); |
| if (r < 0) |
| return log_error_errno(r, "Failed to start bus client: %m"); |
| |
| p->destination_bus = b; |
| b = NULL; |
| return 0; |
| } |
| |
| static int proxy_create_local(Proxy *p, int in_fd, int out_fd, bool negotiate_fds) { |
| _cleanup_bus_flush_close_unref_ sd_bus *b = NULL; |
| sd_id128_t server_id; |
| int r; |
| |
| 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_get_bus_id(p->destination_bus, &server_id); |
| if (r < 0) |
| return log_error_errno(r, "Failed to get server ID: %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, negotiate_fds); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set FD negotiation: %m"); |
| |
| r = sd_bus_negotiate_creds(b, true, SD_BUS_CREDS_EUID|SD_BUS_CREDS_PID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SELINUX_CONTEXT); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set credential negotiation: %m"); |
| |
| r = sd_bus_set_anonymous(b, true); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set anonymous authentication: %m"); |
| |
| b->manual_peer_interface = true; |
| |
| r = sd_bus_start(b); |
| if (r < 0) |
| return log_error_errno(r, "Failed to start bus client: %m"); |
| |
| p->local_bus = b; |
| b = NULL; |
| return 0; |
| } |
| |
| static int proxy_match_synthetic(sd_bus_message *m, void *userdata, sd_bus_error *error) { |
| Proxy *p = userdata; |
| |
| p->synthetic_matched = true; |
| return 0; /* make sure to continue processing it in further handlers */ |
| } |
| |
| /* |
| * We always need NameOwnerChanged so we can synthesize NameLost and |
| * NameAcquired. Furthermore, dbus-1 always passes unicast-signals through, so |
| * subscribe unconditionally. |
| */ |
| static int proxy_prepare_matches(Proxy *p) { |
| _cleanup_free_ char *match = NULL; |
| const char *unique; |
| int r; |
| |
| if (!p->destination_bus->is_kernel) |
| return 0; |
| |
| r = sd_bus_get_unique_name(p->destination_bus, &unique); |
| if (r < 0) |
| return log_error_errno(r, "Failed to get unique name: %m"); |
| |
| match = strjoin("type='signal'," |
| "sender='org.freedesktop.DBus'," |
| "path='/org/freedesktop/DBus'," |
| "interface='org.freedesktop.DBus'," |
| "member='NameOwnerChanged'," |
| "arg1='", |
| unique, |
| "'", |
| NULL); |
| if (!match) |
| return log_oom(); |
| |
| r = sd_bus_add_match(p->destination_bus, NULL, match, proxy_match_synthetic, p); |
| if (r < 0) |
| return log_error_errno(r, "Failed to add match for NameLost: %m"); |
| |
| 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) |
| return log_oom(); |
| |
| r = sd_bus_add_match(p->destination_bus, NULL, match, proxy_match_synthetic, p); |
| if (r < 0) |
| return log_error_errno(r, "Failed to add match for NameAcquired: %m"); |
| |
| free(match); |
| match = strjoin("type='signal'," |
| "destination='", |
| unique, |
| "'", |
| NULL); |
| if (!match) |
| return log_oom(); |
| |
| r = sd_bus_add_match(p->destination_bus, NULL, match, proxy_match_synthetic, p); |
| if (r < 0) |
| log_error_errno(r, "Failed to add match for directed signals: %m"); |
| /* FIXME: temporarily ignore error to support older kdbus versions */ |
| |
| return 0; |
| } |
| |
| int proxy_new(Proxy **out, int in_fd, int out_fd, const char *destination) { |
| _cleanup_(proxy_freep) Proxy *p = NULL; |
| _cleanup_free_ char *local_sec = NULL; |
| bool is_unix; |
| int r; |
| |
| p = new0(Proxy, 1); |
| if (!p) |
| return log_oom(); |
| |
| p->local_in = in_fd; |
| p->local_out = out_fd; |
| |
| p->owned_names = set_new(&string_hash_ops); |
| if (!p->owned_names) |
| return log_oom(); |
| |
| 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) { |
| (void) getpeercred(in_fd, &p->local_creds); |
| (void) getpeersec(in_fd, &local_sec); |
| } |
| |
| r = proxy_create_destination(p, destination, local_sec, is_unix); |
| if (r < 0) |
| return r; |
| |
| r = proxy_create_local(p, in_fd, out_fd, is_unix); |
| if (r < 0) |
| return r; |
| |
| r = proxy_prepare_matches(p); |
| if (r < 0) |
| return r; |
| |
| *out = p; |
| p = NULL; |
| return 0; |
| } |
| |
| Proxy *proxy_free(Proxy *p) { |
| ProxyActivation *activation; |
| |
| if (!p) |
| return NULL; |
| |
| while ((activation = p->activations)) { |
| LIST_REMOVE(activations_by_proxy, p->activations, activation); |
| sd_bus_message_unref(activation->request); |
| sd_bus_slot_unref(activation->slot); |
| free(activation); |
| } |
| |
| sd_bus_flush_close_unref(p->local_bus); |
| sd_bus_flush_close_unref(p->destination_bus); |
| set_free_free(p->owned_names); |
| free(p); |
| |
| return NULL; |
| } |
| |
| int proxy_set_policy(Proxy *p, SharedPolicy *sp, char **configuration) { |
| _cleanup_strv_free_ char **strv = NULL; |
| Policy *policy; |
| int r; |
| |
| assert(p); |
| assert(sp); |
| |
| /* no need to load legacy policy if destination is not kdbus */ |
| if (!p->destination_bus->is_kernel) |
| return 0; |
| |
| p->policy = sp; |
| |
| policy = shared_policy_acquire(sp); |
| if (policy) { |
| /* policy already pre-loaded */ |
| shared_policy_release(sp, policy); |
| return 0; |
| } |
| |
| if (!configuration) { |
| const char *scope; |
| |
| r = sd_bus_get_scope(p->destination_bus, &scope); |
| if (r < 0) |
| return log_error_errno(r, "Couldn't determine bus scope: %m"); |
| |
| if (streq(scope, "system")) |
| strv = strv_new("/usr/share/dbus-1/system.conf", |
| "/etc/dbus-1/system.conf", |
| "/usr/share/dbus-1/system.d/", |
| "/etc/dbus-1/system.d/", |
| "/etc/dbus-1/system-local.conf", |
| NULL); |
| else if (streq(scope, "user")) |
| strv = strv_new("/usr/share/dbus-1/session.conf", |
| "/etc/dbus-1/session.conf", |
| "/usr/share/dbus-1/session.d/", |
| "/etc/dbus-1/session.d/", |
| "/etc/dbus-1/session-local.conf", |
| NULL); |
| else |
| return log_error("Unknown scope %s, don't know which policy to load. Refusing.", scope); |
| |
| if (!strv) |
| return log_oom(); |
| |
| configuration = strv; |
| } |
| |
| return shared_policy_preload(sp, configuration); |
| } |
| |
| int proxy_hello_policy(Proxy *p, uid_t original_uid) { |
| Policy *policy; |
| int r = 0; |
| |
| assert(p); |
| |
| if (!p->policy) |
| return 0; |
| |
| policy = shared_policy_acquire(p->policy); |
| |
| if (p->local_creds.uid == original_uid) |
| log_debug("Permitting access, since bus owner matches bus client."); |
| else if (policy_check_hello(policy, p->local_creds.uid, p->local_creds.gid)) |
| log_debug("Permitting access due to XML policy."); |
| else |
| r = log_error_errno(EPERM, "Policy denied connection."); |
| |
| shared_policy_release(p->policy, policy); |
| |
| return r; |
| } |
| |
| static int proxy_wait(Proxy *p) { |
| uint64_t timeout_destination, timeout_local, t; |
| int events_destination, events_local, fd; |
| struct timespec _ts, *ts; |
| struct pollfd *pollfd; |
| int r; |
| |
| assert(p); |
| |
| fd = sd_bus_get_fd(p->destination_bus); |
| if (fd < 0) |
| return log_error_errno(fd, "Failed to get fd: %m"); |
| |
| events_destination = sd_bus_get_events(p->destination_bus); |
| if (events_destination < 0) |
| return log_error_errno(events_destination, "Failed to get events mask: %m"); |
| |
| r = sd_bus_get_timeout(p->destination_bus, &timeout_destination); |
| if (r < 0) |
| return log_error_errno(r, "Failed to get timeout: %m"); |
| |
| events_local = sd_bus_get_events(p->local_bus); |
| if (events_local < 0) |
| return log_error_errno(events_local, "Failed to get events mask: %m"); |
| |
| r = sd_bus_get_timeout(p->local_bus, &timeout_local); |
| if (r < 0) |
| return log_error_errno(r, "Failed to get timeout: %m"); |
| |
| t = timeout_destination; |
| if (t == (uint64_t) -1 || (timeout_local != (uint64_t) -1 && timeout_local < timeout_destination)) |
| t = timeout_local; |
| |
| 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); |
| } |
| |
| pollfd = (struct pollfd[3]) { |
| { .fd = fd, .events = events_destination, }, |
| { .fd = p->local_in, .events = events_local & POLLIN, }, |
| { .fd = p->local_out, .events = events_local & POLLOUT, }, |
| }; |
| |
| r = ppoll(pollfd, 3, ts, NULL); |
| if (r < 0) |
| return log_error_errno(errno, "ppoll() failed: %m"); |
| |
| return 0; |
| } |
| |
| static int handle_policy_error(sd_bus_message *m, int r) { |
| if (r == -ESRCH || r == -ENXIO) |
| return synthetic_reply_method_errorf(m, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Name %s is currently not owned by anyone.", m->destination); |
| |
| return r; |
| } |
| |
| static int process_policy_unlocked(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *policy, const struct ucred *our_ucred, Set *owned_names) { |
| int r; |
| |
| assert(from); |
| assert(to); |
| assert(m); |
| |
| if (!policy) |
| return 0; |
| |
| /* |
| * dbus-1 distinguishes expected and non-expected replies by tracking |
| * method-calls and timeouts. By default, DENY rules are *NEVER* applied |
| * on expected replies, unless explicitly specified. But we dont track |
| * method-calls, thus, we cannot know whether a reply is expected. |
| * Fortunately, the kdbus forbids non-expected replies, so we can safely |
| * ignore any policy on those and let the kernel deal with it. |
| * |
| * TODO: To be correct, we should only ignore policy-tags that are |
| * applied on non-expected replies. However, so far we don't parse those |
| * tags so we let everything pass. I haven't seen a DENY policy tag on |
| * expected-replies, ever, so don't bother.. |
| */ |
| if (m->reply_cookie > 0) |
| return 0; |
| |
| if (from->is_kernel) { |
| uid_t sender_uid = UID_INVALID; |
| gid_t sender_gid = GID_INVALID; |
| char **sender_names = NULL; |
| |
| /* Driver messages are always OK */ |
| if (streq_ptr(m->sender, "org.freedesktop.DBus")) |
| return 0; |
| |
| /* The message came from the kernel, and is sent to our legacy client. */ |
| (void) sd_bus_creds_get_well_known_names(&m->creds, &sender_names); |
| |
| (void) sd_bus_creds_get_euid(&m->creds, &sender_uid); |
| (void) sd_bus_creds_get_egid(&m->creds, &sender_gid); |
| |
| if (sender_uid == UID_INVALID || sender_gid == GID_INVALID) { |
| _cleanup_bus_creds_unref_ sd_bus_creds *sender_creds = NULL; |
| |
| /* If the message came from another legacy |
| * client, then the message creds will be |
| * missing, simply because on legacy clients |
| * per-message creds were unknown. In this |
| * case, query the creds of the peer |
| * instead. */ |
| |
| r = bus_get_name_creds_kdbus(from, m->sender, SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID, true, &sender_creds); |
| if (r < 0) |
| return handle_policy_error(m, r); |
| |
| (void) sd_bus_creds_get_euid(sender_creds, &sender_uid); |
| (void) sd_bus_creds_get_egid(sender_creds, &sender_gid); |
| } |
| |
| /* First check whether the sender can send the message to our name */ |
| if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, owned_names, NULL, m->path, m->interface, m->member, false, NULL) && |
| policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, sender_names, m->path, m->interface, m->member, false)) |
| return 0; |
| |
| /* Return an error back to the caller */ |
| if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL) |
| return synthetic_reply_method_errorf(m, SD_BUS_ERROR_ACCESS_DENIED, "Access prohibited by XML receiver policy."); |
| |
| /* Return 1, indicating that the message shall not be processed any further */ |
| return 1; |
| } |
| |
| if (to->is_kernel) { |
| _cleanup_bus_creds_unref_ sd_bus_creds *destination_creds = NULL; |
| uid_t destination_uid = UID_INVALID; |
| gid_t destination_gid = GID_INVALID; |
| const char *destination_unique = NULL; |
| char **destination_names = NULL; |
| char *n; |
| |
| /* Driver messages are always OK */ |
| if (streq_ptr(m->destination, "org.freedesktop.DBus")) |
| return 0; |
| |
| /* The message came from the legacy client, and is sent to kdbus. */ |
| if (m->destination) { |
| r = bus_get_name_creds_kdbus(to, m->destination, |
| SD_BUS_CREDS_WELL_KNOWN_NAMES|SD_BUS_CREDS_UNIQUE_NAME| |
| SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_PID, |
| true, &destination_creds); |
| if (r < 0) |
| return handle_policy_error(m, r); |
| |
| r = sd_bus_creds_get_unique_name(destination_creds, &destination_unique); |
| if (r < 0) |
| return handle_policy_error(m, r); |
| |
| (void) sd_bus_creds_get_well_known_names(destination_creds, &destination_names); |
| |
| (void) sd_bus_creds_get_euid(destination_creds, &destination_uid); |
| (void) sd_bus_creds_get_egid(destination_creds, &destination_gid); |
| } |
| |
| /* First check if we (the sender) can send to this name */ |
| if (sd_bus_message_is_signal(m, NULL, NULL)) { |
| /* If we forward a signal from dbus-1 to kdbus, we have |
| * no idea who the recipient is. Therefore, we cannot |
| * apply any dbus-1 policies that match on receiver |
| * credentials. We know sd-bus always sets |
| * KDBUS_MSG_SIGNAL, so the kernel applies policies to |
| * the message. Therefore, skip policy checks in this |
| * case. */ |
| return 0; |
| } else if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, destination_names, m->path, m->interface, m->member, true, &n)) { |
| if (n) { |
| /* If we made a receiver decision, then remember which |
| * name's policy we used, and to which unique ID it |
| * mapped when we made the decision. Then, let's pass |
| * this to the kernel when sending the message, so that |
| * it refuses the operation should the name and unique |
| * ID not map to each other anymore. */ |
| |
| r = free_and_strdup(&m->destination_ptr, n); |
| if (r < 0) |
| return r; |
| |
| r = bus_kernel_parse_unique_name(destination_unique, &m->verify_destination_id); |
| if (r < 0) |
| return r; |
| } |
| |
| if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, owned_names, NULL, m->path, m->interface, m->member, true)) |
| return 0; |
| } |
| |
| /* Return an error back to the caller */ |
| if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL) |
| return synthetic_reply_method_errorf(m, SD_BUS_ERROR_ACCESS_DENIED, "Access prohibited by XML sender policy."); |
| |
| /* Return 1, indicating that the message shall not be processed any further */ |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, SharedPolicy *sp, const struct ucred *our_ucred, Set *owned_names) { |
| Policy *policy; |
| int r; |
| |
| assert(sp); |
| |
| policy = shared_policy_acquire(sp); |
| r = process_policy_unlocked(from, to, m, policy, our_ucred, owned_names); |
| shared_policy_release(sp, policy); |
| |
| return r; |
| } |
| |
| static int process_hello(Proxy *p, sd_bus_message *m) { |
| _cleanup_bus_message_unref_ sd_bus_message *n = NULL; |
| bool is_hello; |
| int r; |
| |
| assert(p); |
| assert(m); |
| |
| /* 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 (p->got_hello) |
| return 0; |
| |
| return log_error_errno(EIO, "First packet isn't hello (it's %s.%s), aborting.", m->interface, m->member); |
| } |
| |
| if (p->got_hello) |
| return log_error_errno(EIO, "Got duplicate hello, aborting."); |
| |
| p->got_hello = true; |
| |
| if (!p->destination_bus->is_kernel) |
| return 0; |
| |
| r = sd_bus_message_new_method_return(m, &n); |
| if (r < 0) |
| return log_error_errno(r, "Failed to generate HELLO reply: %m"); |
| |
| r = sd_bus_message_append(n, "s", p->destination_bus->unique_name); |
| if (r < 0) |
| return log_error_errno(r, "Failed to append unique name to HELLO reply: %m"); |
| |
| r = bus_message_append_sender(n, "org.freedesktop.DBus"); |
| if (r < 0) |
| return log_error_errno(r, "Failed to append sender to HELLO reply: %m"); |
| |
| r = bus_seal_synthetic_message(p->local_bus, n); |
| if (r < 0) |
| return log_error_errno(r, "Failed to seal HELLO reply: %m"); |
| |
| r = sd_bus_send(p->local_bus, n, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to send HELLO reply: %m"); |
| |
| n = sd_bus_message_unref(n); |
| r = sd_bus_message_new_signal( |
| p->local_bus, |
| &n, |
| "/org/freedesktop/DBus", |
| "org.freedesktop.DBus", |
| "NameAcquired"); |
| if (r < 0) |
| return log_error_errno(r, "Failed to allocate initial NameAcquired message: %m"); |
| |
| r = sd_bus_message_append(n, "s", p->destination_bus->unique_name); |
| if (r < 0) |
| return log_error_errno(r, "Failed to append unique name to NameAcquired message: %m"); |
| |
| r = bus_message_append_sender(n, "org.freedesktop.DBus"); |
| if (r < 0) |
| return log_error_errno(r, "Failed to append sender to NameAcquired message: %m"); |
| |
| r = sd_bus_message_set_destination(n, p->destination_bus->unique_name); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set destination for NameAcquired message: %m"); |
| |
| r = bus_seal_synthetic_message(p->local_bus, n); |
| if (r < 0) |
| return log_error_errno(r, "Failed to seal NameAcquired message: %m"); |
| |
| r = sd_bus_send(p->local_bus, n, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to send NameAcquired message: %m"); |
| |
| 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; |
| } |
| |
| static int proxy_process_destination_to_local(Proxy *p) { |
| _cleanup_bus_message_unref_ sd_bus_message *m = NULL; |
| bool matched, matched_synthetic; |
| int r; |
| |
| assert(p); |
| |
| /* |
| * Usually, we would just take any message that the bus passes to us |
| * and forward it to the local connection. However, there are actually |
| * applications that fail if they receive broadcasts that they didn't |
| * subscribe to. Therefore, we actually emulate a real broadcast |
| * matching here, and discard any broadcasts that weren't matched. Our |
| * match-handlers remembers whether a message was matched by any rule, |
| * by marking it in @p->message_matched. |
| */ |
| |
| r = sd_bus_process(p->destination_bus, &m); |
| |
| matched = p->message_matched; |
| matched_synthetic = p->synthetic_matched; |
| p->message_matched = false; |
| p->synthetic_matched = false; |
| |
| if (r == -ECONNRESET || r == -ENOTCONN) /* Treat 'connection reset by peer' as clean exit condition */ |
| return r; |
| if (r < 0) { |
| log_error_errno(r, "Failed to process destination bus: %m"); |
| return r; |
| } |
| if (r == 0) |
| return 0; |
| if (!m) |
| return 1; |
| |
| /* We officially got EOF, let's quit */ |
| if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) |
| return -ECONNRESET; |
| |
| r = synthesize_name_acquired(p, p->destination_bus, p->local_bus, m); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| if (r < 0) |
| return log_error_errno(r, "Failed to synthesize message: %m"); |
| |
| /* discard broadcasts that were not matched by any MATCH rule */ |
| if (!matched && !sd_bus_message_get_destination(m)) { |
| if (!matched_synthetic) |
| log_debug("Dropped unmatched broadcast: uid=" UID_FMT " gid=" GID_FMT " pid=" PID_FMT " message=%s path=%s interface=%s member=%s sender=%s destination=%s", |
| p->local_creds.uid, p->local_creds.gid, p->local_creds.pid, bus_message_type_to_string(m->header->type), |
| strna(m->path), strna(m->interface), strna(m->member), strna(m->sender), strna(m->destination)); |
| return 1; |
| } |
| |
| patch_sender(p->destination_bus, m); |
| |
| if (p->policy) { |
| r = process_policy(p->destination_bus, p->local_bus, m, p->policy, &p->local_creds, p->owned_names); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| if (r < 0) |
| return log_error_errno(r, "Failed to process policy: %m"); |
| if (r > 0) |
| return 1; |
| } |
| |
| r = sd_bus_send(p->local_bus, m, NULL); |
| if (r < 0) { |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| |
| /* If the peer tries to send a reply and it is |
| * rejected with EBADSLT by the kernel, we ignore the |
| * error. This catches cases where the original |
| * method-call didn't had EXPECT_REPLY set, but the |
| * proxy-peer still sends a reply. This is allowed in |
| * dbus1, but not in kdbus. We don't want to track |
| * reply-windows in the proxy, so we simply ignore |
| * EBADSLT for all replies. The only downside is, that |
| * callers are no longer notified if their replies are |
| * dropped. However, this is equivalent to the |
| * caller's timeout to expire, so this should be |
| * acceptable. Nobody sane sends replies without a |
| * matching method-call, so nobody should care. */ |
| |
| /* FIXME: remove -EPERM when kdbus is updated */ |
| if ((r == -EPERM || r == -EBADSLT) && m->reply_cookie > 0) |
| return 1; |
| |
| /* Return the error to the client, if we can */ |
| synthetic_reply_method_errnof(m, r, "Failed to forward message we got from destination: %m"); |
| if (r == -ENOBUFS) { |
| /* if local dbus1 peer does not dispatch its queue, warn only once */ |
| if (!p->queue_overflow) |
| log_error("Dropped messages due to queue overflow of local peer (pid: "PID_FMT" uid: "UID_FMT")", p->local_creds.pid, p->local_creds.uid); |
| p->queue_overflow = true; |
| } else |
| log_error_errno(r, |
| "Failed to forward message we got from destination: uid=" UID_FMT " gid=" GID_FMT" message=%s destination=%s path=%s interface=%s member=%s: %m", |
| p->local_creds.uid, p->local_creds.gid, bus_message_type_to_string(m->header->type), |
| strna(m->destination), strna(m->path), strna(m->interface), strna(m->member)); |
| |
| return 1; |
| } |
| |
| p->queue_overflow = false; |
| return 1; |
| } |
| |
| static int proxy_process_local_to_destination(Proxy *p) { |
| _cleanup_bus_message_unref_ sd_bus_message *m = NULL; |
| int r; |
| |
| assert(p); |
| |
| r = sd_bus_process(p->local_bus, &m); |
| if (r == -ECONNRESET || r == -ENOTCONN) /* Treat 'connection reset by peer' as clean exit condition */ |
| return r; |
| if (r < 0) { |
| log_error_errno(r, "Failed to process local bus: %m"); |
| return r; |
| } |
| if (r == 0) |
| return 0; |
| if (!m) |
| return 1; |
| |
| /* We officially got EOF, let's quit */ |
| if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) |
| return -ECONNRESET; |
| |
| r = process_hello(p, m); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| if (r < 0) |
| return log_error_errno(r, "Failed to process HELLO: %m"); |
| if (r > 0) |
| return 1; |
| |
| r = bus_proxy_process_driver(p, p->destination_bus, p->local_bus, m, p->policy, &p->local_creds, p->owned_names); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| if (r < 0) |
| return log_error_errno(r, "Failed to process driver calls: %m"); |
| if (r > 0) |
| return 1; |
| |
| for (;;) { |
| if (p->policy) { |
| r = process_policy(p->local_bus, p->destination_bus, m, p->policy, &p->local_creds, p->owned_names); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| if (r < 0) |
| return log_error_errno(r, "Failed to process policy: %m"); |
| if (r > 0) |
| return 1; |
| } |
| |
| r = sd_bus_send(p->destination_bus, m, NULL); |
| if (r < 0) { |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return r; |
| |
| /* The name database changed since the policy check, hence let's check again */ |
| if (r == -EREMCHG) |
| continue; |
| |
| /* see above why EBADSLT is ignored for replies */ |
| if ((r == -EPERM || r == -EBADSLT) && m->reply_cookie > 0) |
| return 1; |
| |
| synthetic_reply_method_errnof(m, r, "Failed to forward message we got from local: %m"); |
| log_error_errno(r, |
| "Failed to forward message we got from local: uid=" UID_FMT " gid=" GID_FMT" message=%s destination=%s path=%s interface=%s member=%s: %m", |
| p->local_creds.uid, p->local_creds.gid, bus_message_type_to_string(m->header->type), |
| strna(m->destination), strna(m->path), strna(m->interface), strna(m->member)); |
| return 1; |
| } |
| |
| break; |
| } |
| |
| return 1; |
| } |
| |
| int proxy_match(sd_bus_message *m, void *userdata, sd_bus_error *error) { |
| Proxy *p = userdata; |
| |
| p->message_matched = true; |
| return 0; /* make sure to continue processing it in further handlers */ |
| } |
| |
| int proxy_run(Proxy *p) { |
| int r; |
| |
| assert(p); |
| |
| for (;;) { |
| bool busy = false; |
| |
| if (p->got_hello) { |
| /* Read messages from bus, to pass them on to our client */ |
| r = proxy_process_destination_to_local(p); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return 0; |
| if (r < 0) |
| return r; |
| if (r > 0) |
| busy = true; |
| } |
| |
| /* Read messages from our client, to pass them on to the bus */ |
| r = proxy_process_local_to_destination(p); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return 0; |
| if (r < 0) |
| return r; |
| if (r > 0) |
| busy = true; |
| |
| if (!busy) { |
| r = proxy_wait(p); |
| if (r == -ECONNRESET || r == -ENOTCONN) |
| return 0; |
| if (r < 0) |
| return r; |
| } |
| } |
| |
| return 0; |
| } |