bus: implicitly handle peer commands Ping() and GetMachineId()

[elogind.git] / src / libsystemd-bus / sd-bus.c

diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index ad840cc875c6e4bf87ab072435f8b620a58527b1..049bd356a06f10deac234bf0f60e8c2c7a0c3949 100644 (file)
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -35,8 +35,6 @@
 #include "bus-message.h"
 #include "bus-type.h"
 
-#define WQUEUE_MAX 128
-
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
 
 static void bus_free(sd_bus *b) {
@@ -495,6 +493,13 @@ static int bus_read_auth(sd_bus *b) {
                 return r;
 
         n = MAX(3 + 32 + 2 + sizeof("AGREE_UNIX_FD") - 1 + 2, b->rbuffer_size * 2);
+
+        if (n > BUS_AUTH_SIZE_MAX)
+                n = BUS_AUTH_SIZE_MAX;
+
+        if (b->rbuffer_size >= n)
+                return -ENOBUFS;
+
         p = realloc(b->rbuffer, n);
         if (!p)
                 return -ENOMEM;
@@ -845,6 +850,7 @@ static int message_write(sd_bus *bus, sd_bus_message *m, size_t *idx) {
 static int message_read_need(sd_bus *bus, size_t *need) {
         uint32_t a, b;
         uint8_t e;
+        uint64_t sum;
 
         assert(bus);
         assert(need);
@@ -885,7 +891,11 @@ static int message_read_need(sd_bus *bus, size_t *need) {
         } else
                 return -EBADMSG;
 
-        *need = sizeof(struct bus_header) + ALIGN_TO(b, 8) + a;
+        sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a;
+        if (sum >= BUS_MESSAGE_SIZE_MAX)
+                return -ENOBUFS;
+
+        *need = (size_t) sum;
         return 0;
 }
 
@@ -1093,7 +1103,7 @@ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
 
                 /* Just append it to the queue. */
 
-                if (bus->wqueue_size >= WQUEUE_MAX)
+                if (bus->wqueue_size >= BUS_WQUEUE_MAX)
                         return -ENOBUFS;
 
                 q = realloc(bus->wqueue, sizeof(sd_bus_message*) * (bus->wqueue_size + 1));
@@ -1300,6 +1310,9 @@ int sd_bus_send_with_reply_and_block(
                 if (!room) {
                         sd_bus_message **q;
 
+                        if (bus->rqueue_size >= BUS_RQUEUE_MAX)
+                                return -ENOBUFS;
+
                         /* Make sure there's room for queuing this
                          * locally, before we read the message */
 
@@ -1462,6 +1475,57 @@ static int process_timeout(sd_bus *bus) {
         return r < 0 ? r : 1;
 }
 
+static int process_builtin(sd_bus *bus, sd_bus_message *m) {
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        int r;
+
+        assert(bus);
+        assert(m);
+
+        if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
+                return 0;
+
+        if (!streq_ptr(m->interface, "org.freedesktop.DBus.Peer"))
+                return 0;
+
+        if (m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED)
+                return 1;
+
+        if (streq_ptr(m->member, "Ping"))
+                r = sd_bus_message_new_method_return(bus, m, &reply);
+        else if (streq_ptr(m->member, "GetMachineId")) {
+                sd_id128_t id;
+                char sid[33];
+
+                r = sd_id128_get_machine(&id);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_new_method_return(bus, m, &reply);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append(reply, "s", sd_id128_to_string(id, sid));
+        } else {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_INIT;
+
+                sd_bus_error_set(&error,
+                                 "org.freedesktop.DBus.Error.UnknownMethod",
+                                 "Unknown method '%s' on interface '%s'.", m->member, m->interface);
+
+                r = sd_bus_message_new_method_error(bus, m, &error, &reply);
+        }
+
+        if (r < 0)
+                return r;
+
+        r = sd_bus_send(bus, reply, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
 static int process_message(sd_bus *bus, sd_bus_message *m) {
         struct filter_callback *l;
         int r;
@@ -1469,7 +1533,7 @@ static int process_message(sd_bus *bus, sd_bus_message *m) {
         assert(bus);
         assert(m);
 
-        if (m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_CALL || m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_RETURN) {
+        if (m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_RETURN || m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_ERROR) {
                 struct reply_callback *c;
 
                 c = hashmap_remove(bus->reply_callbacks, &m->reply_serial);
@@ -1491,7 +1555,7 @@ static int process_message(sd_bus *bus, sd_bus_message *m) {
                         return r;
         }
 
-        return 0;
+        return process_builtin(bus, m);
 }
 
 int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
@@ -1586,11 +1650,13 @@ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
                         return 1;
                 }
 
-                if (sd_bus_message_is_method_call(m, NULL, NULL)) {
-                        const sd_bus_error e = SD_BUS_ERROR_INIT_CONST("org.freedesktop.DBus.Error.UnknownObject", "Unknown object.");
+                if (m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_CALL) {
                         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+                        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_INIT;
+
+                        sd_bus_error_set(&error, "org.freedesktop.DBus.Error.UnknownObject", "Unknown object '%s'.", m->path);
 
-                        r = sd_bus_message_new_method_error(bus, m, &e, &reply);
+                        r = sd_bus_message_new_method_error(bus, m, &error, &reply);
                         if (r < 0)
                                 return r;