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Diffstat (limited to 'src/bus-proxyd/bus-proxyd.c')
-rw-r--r--src/bus-proxyd/bus-proxyd.c449
1 files changed, 285 insertions, 164 deletions
diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c
index 4df2fb10af..50ffd0ac16 100644
--- a/src/bus-proxyd/bus-proxyd.c
+++ b/src/bus-proxyd/bus-proxyd.c
@@ -51,8 +51,6 @@ static char *arg_command_line_buffer = NULL;
static bool arg_drop_privileges = false;
static char **arg_configuration = NULL;
-static Hashmap *names_hash = NULL;
-
static int help(void) {
printf("%s [OPTIONS...]\n\n"
@@ -442,95 +440,7 @@ static int get_creds_by_message(sd_bus *bus, sd_bus_message *m, uint64_t mask, s
return get_creds_by_name(bus, name, mask, _creds, error);
}
-static int process_policy(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred) {
- int r;
- char **name;
- char **names_strv;
- bool granted = false;
- Iterator i;
-
- assert(a);
- assert(b);
- assert(m);
-
- if (!policy)
- return 0;
-
- if (b->is_kernel) {
-
- /* The message came from the kernel, and is sent to our legacy client. */
- r = sd_bus_creds_get_well_known_names(&m->creds, &names_strv);
- if (r < 0)
- return r;
-
- STRV_FOREACH(name, names_strv) {
- if (policy_check_send(policy, ucred, m->header->type, *name, m->path, m->interface, m->member)) {
- r = free_and_strdup(&m->destination_ptr, *name);
- if (r < 0)
- break;
-
- granted = true;
- break;
- }
- }
-
- if (r < 0)
- return r;
-
- if (!granted)
- return -EPERM;
-
- granted = false;
-
- HASHMAP_FOREACH(name, names_hash, i) {
- if (policy_check_recv(policy, ucred, m->header->type, *name, m->path, m->interface, m->member))
- return 0;
- }
-
- return -EPERM;
- } else {
- sd_bus_creds *bus_creds;
-
- /* The message came from the legacy client, and is sent to kdbus. */
- r = sd_bus_get_name_creds(a, m->destination, SD_BUS_CREDS_WELL_KNOWN_NAMES, &bus_creds);
- if (r < 0)
- return r;
-
- STRV_FOREACH(name, names_strv) {
- if (policy_check_send(policy, ucred, m->header->type, *name, m->path, m->interface, m->member)) {
- r = free_and_strdup(&m->destination_ptr, *name);
- if (r < 0)
- break;
-
- r = bus_kernel_parse_unique_name(m->sender, &m->verify_destination_id);
- if (r < 0)
- break;
-
- granted = true;
- break;
- }
- }
-
- if (r < 0)
- return r;
-
- if (!granted)
- return -EPERM;
-
- granted = false;
-
- HASHMAP_FOREACH(name, names_hash, i) {
- if (policy_check_recv(policy, ucred, m->header->type, *name, m->path, m->interface, m->member))
- return 0;
- }
-
- return -EPERM;
- }
-
- return 0;
-}
-
-static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred) {
+static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, Set *owned_names) {
int r;
assert(a);
@@ -883,7 +793,7 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic
return synthetic_reply_method_errno(m, r, NULL);
}
- hashmap_remove(names_hash, name);
+ set_remove(owned_names, (char*) name);
return synthetic_reply_method_return(m, "u", BUS_NAME_RELEASED);
@@ -909,7 +819,7 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic
if (r < 0)
return synthetic_reply_method_errno(m, r, NULL);
- if (policy && !policy_check_own(policy, ucred, name))
+ if (policy && !policy_check_own(policy, ucred->uid, ucred->gid, name))
return synthetic_reply_method_errno(m, -EPERM, NULL);
if ((flags & ~(BUS_NAME_ALLOW_REPLACEMENT|BUS_NAME_REPLACE_EXISTING|BUS_NAME_DO_NOT_QUEUE)) != 0)
@@ -923,21 +833,24 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic
if (!(flags & BUS_NAME_DO_NOT_QUEUE))
param |= SD_BUS_NAME_QUEUE;
+ r = set_put_strdup(owned_names, name);
+ if (r < 0)
+ return synthetic_reply_method_errno(m, r, NULL);
+
r = sd_bus_request_name(a, name, param);
if (r < 0) {
- if (r == -EEXIST)
- return synthetic_reply_method_return(m, "u", BUS_NAME_EXISTS);
if (r == -EALREADY)
return synthetic_reply_method_return(m, "u", BUS_NAME_ALREADY_OWNER);
+
+ set_remove(owned_names, (char*) name);
+
+ if (r == -EEXIST)
+ return synthetic_reply_method_return(m, "u", BUS_NAME_EXISTS);
return synthetic_reply_method_errno(m, r, NULL);
}
in_queue = (r == 0);
- r = hashmap_put(names_hash, name, NULL);
- if (r < 0)
- return synthetic_reply_method_errno(m, r, NULL);
-
if (in_queue)
return synthetic_reply_method_return(m, "u", BUS_NAME_IN_QUEUE);
@@ -1049,7 +962,166 @@ static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *polic
}
}
-static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, bool *got_hello) {
+static int process_policy(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;
+
+ if (from->is_kernel) {
+ uid_t sender_uid = (uid_t) -1;
+ gid_t sender_gid = (gid_t) -1;
+ char **sender_names = NULL;
+ bool granted = false;
+
+ /* 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. */
+ r = sd_bus_creds_get_well_known_names(&m->creds, &sender_names);
+ if (r < 0)
+ return r;
+
+ (void) sd_bus_creds_get_uid(&m->creds, &sender_uid);
+ (void) sd_bus_creds_get_gid(&m->creds, &sender_gid);
+
+ /* First check whether the sender can send the message to our name */
+ if (set_isempty(owned_names)) {
+ if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, NULL, m->path, m->interface, m->member))
+ granted = true;
+ } else {
+ Iterator i;
+ char *n;
+
+ SET_FOREACH(n, owned_names, i)
+ if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, n, m->path, m->interface, m->member)) {
+ granted = true;
+ break;
+ }
+ }
+
+ if (granted) {
+ /* Then check whether us, the recipient can recieve from the sender's name */
+ if (strv_isempty(sender_names)) {
+ if (policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, m->path, m->interface, m->member))
+ return 0;
+ } else {
+ char **n;
+
+ STRV_FOREACH(n, sender_names) {
+ if (policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, *n, m->path, m->interface, m->member))
+ return 0;
+ }
+ }
+ }
+
+ /* Return an error back to the caller */
+ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+ return sd_bus_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_t) -1;
+ gid_t destination_gid = (gid_t) -1;
+ const char *destination_unique = NULL;
+ char **destination_names = NULL;
+ bool granted = false;
+
+ /* 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 = sd_bus_get_name_creds(to, m->destination,
+ SD_BUS_CREDS_WELL_KNOWN_NAMES|SD_BUS_CREDS_UNIQUE_NAME|
+ SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID, &destination_creds);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_creds_get_well_known_names(destination_creds, &destination_names);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_creds_get_unique_name(destination_creds, &destination_unique);
+ if (r < 0)
+ return r;
+
+ (void) sd_bus_creds_get_uid(destination_creds, &destination_uid);
+ (void) sd_bus_creds_get_gid(destination_creds, &destination_gid);
+ }
+
+ /* First check if we, the sender can send to this name */
+ if (strv_isempty(destination_names)) {
+ if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, m->path, m->interface, m->member))
+ granted = true;
+ } else {
+ char **n;
+
+ STRV_FOREACH(n, destination_names) {
+ if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, *n, m->path, m->interface, m->member)) {
+
+ /* 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)
+ break;
+
+ granted = true;
+ break;
+ }
+ }
+ }
+
+ /* Then check if the recipient can receive from our name */
+ if (granted) {
+ if (set_isempty(owned_names)) {
+ if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, NULL, m->path, m->interface, m->member))
+ return 0;
+ } else {
+ Iterator i;
+ char *n;
+
+ SET_FOREACH(n, owned_names, i)
+ if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, n, m->path, m->interface, m->member))
+ return 0;
+ }
+ }
+
+ /* Return an error back to the caller */
+ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+ return sd_bus_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_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;
@@ -1081,11 +1153,6 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy
return -EIO;
}
- if (policy && !policy_check_hello(policy, ucred)) {
- log_error("Policy denied HELLO");
- return -EPERM;
- }
-
*got_hello = true;
if (!a->is_kernel)
@@ -1192,7 +1259,6 @@ static int patch_sender(sd_bus *a, sd_bus_message *m) {
int main(int argc, char *argv[]) {
- _cleanup_bus_creds_unref_ sd_bus_creds *bus_creds = NULL;
_cleanup_bus_close_unref_ sd_bus *a = NULL, *b = NULL;
sd_id128_t server_id;
int r, in_fd, out_fd;
@@ -1200,7 +1266,8 @@ int main(int argc, char *argv[]) {
bool is_unix;
struct ucred ucred = {};
_cleanup_free_ char *peersec = NULL;
- Policy policy = {};
+ Policy policy_buffer = {}, *policy = NULL;
+ _cleanup_set_free_free_ Set *owned_names = NULL;
log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
log_parse_environment();
@@ -1210,14 +1277,6 @@ int main(int argc, char *argv[]) {
if (r <= 0)
goto finish;
- r = policy_load(&policy, arg_configuration);
- if (r < 0) {
- log_error("Failed to load policy: %s", strerror(-r));
- goto finish;
- }
-
- /* policy_dump(&policy); */
-
r = sd_listen_fds(0);
if (r == 0) {
in_fd = STDIN_FILENO;
@@ -1255,8 +1314,8 @@ int main(int argc, char *argv[]) {
goto finish;
}
- names_hash = hashmap_new(&string_hash_ops);
- if (!names_hash) {
+ owned_names = set_new(&string_hash_ops);
+ if (!owned_names) {
log_oom();
goto finish;
}
@@ -1285,6 +1344,12 @@ int main(int argc, char *argv[]) {
goto finish;
}
+ r = sd_bus_negotiate_creds(a, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_GID|SD_BUS_CREDS_SELINUX_CONTEXT);
+ if (r < 0) {
+ log_error("Failed to set credential negotiation: %s", strerror(-r));
+ goto finish;
+ }
+
if (ucred.pid > 0) {
a->fake_pids.pid = ucred.pid;
a->fake_pids_valid = true;
@@ -1319,10 +1384,41 @@ int main(int argc, char *argv[]) {
goto finish;
}
- r = sd_bus_get_owner_creds(a, SD_BUS_CREDS_UID, &bus_creds);
- if (r < 0) {
- log_error("Failed to get bus creds: %s", strerror(-r));
- goto finish;
+ if (a->is_kernel) {
+ _cleanup_bus_creds_unref_ sd_bus_creds *bus_creds = NULL;
+ uid_t bus_uid;
+
+ r = sd_bus_get_owner_creds(a, SD_BUS_CREDS_UID, &bus_creds);
+ if (r < 0) {
+ log_error("Failed to get bus creds: %s", strerror(-r));
+ goto finish;
+ }
+
+ r = sd_bus_creds_get_uid(bus_creds, &bus_uid);
+ if (r < 0) {
+ log_error("Failed to get bus owner UID: %s", strerror(-r));
+ goto finish;
+ }
+
+ if (bus_uid == 0) {
+ /* We only enforce the old XML policy on
+ * kernel busses owned by root users. */
+
+ r = policy_load(&policy_buffer, arg_configuration);
+ if (r < 0) {
+ log_error("Failed to load policy: %s", strerror(-r));
+ goto finish;
+ }
+
+ if (!policy_check_hello(&policy_buffer, ucred.uid, ucred.gid)) {
+ log_error("Policy denied connection");
+ r = -EPERM;
+ goto finish;
+ }
+
+ policy_dump(&policy_buffer);
+ policy = &policy_buffer;
+ }
}
r = sd_bus_new(&b);
@@ -1349,6 +1445,12 @@ int main(int argc, char *argv[]) {
goto finish;
}
+ r = sd_bus_negotiate_creds(b, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_GID|SD_BUS_CREDS_SELINUX_CONTEXT);
+ if (r < 0) {
+ log_error("Failed to set credential 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));
@@ -1428,6 +1530,8 @@ int main(int argc, char *argv[]) {
int k;
if (got_hello) {
+ /* Read messages from bus, to pass them on to our client */
+
r = sd_bus_process(a, &m);
if (r < 0) {
/* treat 'connection reset by peer' as clean exit condition */
@@ -1440,6 +1544,8 @@ int main(int argc, char *argv[]) {
}
if (m) {
+ bool processed = false;
+
/* We officially got EOF, let's quit */
if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) {
r = 0;
@@ -1455,16 +1561,31 @@ int main(int argc, char *argv[]) {
patch_sender(a, m);
- k = sd_bus_send(b, m, NULL);
- if (k < 0) {
- if (k == -ECONNRESET)
- r = 0;
- else {
+ if (policy) {
+ k = process_policy(a, b, m, policy, &ucred, owned_names);
+ if (k < 0) {
r = k;
- log_error("Failed to send message: %s", strerror(-r));
+ log_error("Failed to process policy: %s", strerror(-r));
+ goto finish;
+ } else if (k > 0) {
+ r = 1;
+ processed = true;
}
+ }
- goto finish;
+ if (!processed) {
+ k = sd_bus_send(b, m, NULL);
+ if (k < 0) {
+ if (k == -ECONNRESET)
+ r = 0;
+ else {
+ r = k;
+ log_error("Failed to send message to client: %s", strerror(-r));
+ }
+
+ goto finish;
+ } else
+ r = 1;
}
}
@@ -1472,6 +1593,7 @@ int main(int argc, char *argv[]) {
continue;
}
+ /* Read messages from our client, to pass them on to the bus */
r = sd_bus_process(b, &m);
if (r < 0) {
/* treat 'connection reset by peer' as clean exit condition */
@@ -1484,15 +1606,7 @@ int main(int argc, char *argv[]) {
}
if (m) {
- Policy *p = NULL;
- uid_t uid;
-
- assert_se(sd_bus_creds_get_uid(bus_creds, &uid) == 0);
-
-/*
- if (uid == 0 || uid != ucred.uid)
- p = &policy;
-*/
+ bool processed = false;
/* We officially got EOF, let's quit */
if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) {
@@ -1500,53 +1614,61 @@ int main(int argc, char *argv[]) {
goto finish;
}
- k = process_hello(a, b, m, p, &ucred, &got_hello);
+ k = process_hello(a, b, m, &got_hello);
if (k < 0) {
r = k;
log_error("Failed to process HELLO: %s", strerror(-r));
goto finish;
+ } else if (k > 0) {
+ processed = true;
+ r = 1;
}
- if (k > 0)
- r = k;
- else {
- k = process_driver(a, b, m, p, &ucred);
+ if (!processed) {
+ k = process_driver(a, b, m, policy, &ucred, owned_names);
if (k < 0) {
r = k;
log_error("Failed to process driver calls: %s", strerror(-r));
goto finish;
+ } else if (k > 0) {
+ processed = true;
+ r = 1;
}
- if (k > 0)
- r = k;
- else {
- bool retry;
-
- do {
- retry = false;
+ if (!processed) {
- k = process_policy(a, b, m, p, &ucred);
- if (k < 0) {
- r = k;
- log_error("Failed to process policy: %s", strerror(-r));
- goto finish;
+ for (;;) {
+ if (policy) {
+ k = process_policy(b, a, m, policy, &ucred, owned_names);
+ if (k < 0) {
+ r = k;
+ log_error("Failed to process policy: %s", strerror(-r));
+ goto finish;
+ } else if (k > 0) {
+ processed = true;
+ r = 1;
+ break;
+ }
}
k = sd_bus_send(a, m, NULL);
if (k < 0) {
- if (k == -ECONNRESET)
+ if (k == -EREMCHG)
+ /* The name database changed since the policy check, hence let's check again */
+ continue;
+ else if (k == -ECONNRESET)
r = 0;
- else if (k == -EREMCHG)
- retry = true;
else {
r = k;
- log_error("Failed to send message: %s", strerror(-r));
+ log_error("Failed to send message to bus: %s", strerror(-r));
}
- if (!retry)
- goto finish;
- }
- } while (retry);
+ goto finish;
+ } else
+ r = 1;
+
+ break;
+ }
}
}
}
@@ -1620,9 +1742,8 @@ finish:
"STOPPING=1\n"
"STATUS=Shutting down.");
- policy_free(&policy);
+ policy_free(&policy_buffer);
strv_free(arg_configuration);
- hashmap_free(names_hash);
free(arg_address);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-02 14:51:10 +0000