sd-bus: add suppot for renegotiating message credential attach flags

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

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index 79d29dc119798b0da25e319fdf65a9dd3d207dae..d0cb7eec1bc448bb1f4912aa6937895a8a3971e0 100644 (file)
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -628,9 +628,15 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         break;
 
                 case KDBUS_ITEM_AUDIT:
-                        m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
-                        m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
-                        m->creds.mask |= (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID) & bus->creds_mask;
+                        if ((uint32_t) d->audit.sessionid != (uint32_t) -1) {
+                                m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
+                                m->creds.mask |= SD_BUS_CREDS_AUDIT_SESSION_ID & bus->creds_mask;
+                        }
+
+                        if ((uid_t) d->audit.loginuid != (uid_t) -1) {
+                                m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
+                                m->creds.mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID & bus->creds_mask;
+                        }
                         break;
 
                 case KDBUS_ITEM_CAPS:
@@ -640,19 +646,27 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         break;
 
                 case KDBUS_ITEM_DST_NAME:
-                        if (!service_name_is_valid(d->str))
-                                return -EBADMSG;
+                        if (!service_name_is_valid(d->str)) {
+                                r = -EBADMSG;
+                                goto fail;
+                        }
 
                         destination = d->str;
                         break;
 
                 case KDBUS_ITEM_OWNED_NAME:
-                        if (!service_name_is_valid(d->name.name))
-                                return -EBADMSG;
-
-                        r = strv_extend(&m->creds.well_known_names, d->name.name);
-                        if (r < 0)
+                        if (!service_name_is_valid(d->name.name)) {
+                                r = -EBADMSG;
                                 goto fail;
+                        }
+
+                        if (bus->creds_mask & SD_BUS_CREDS_WELL_KNOWN_NAMES) {
+                                r = strv_extend(&m->creds.well_known_names, d->name.name);
+                                if (r < 0)
+                                        goto fail;
+
+                                m->creds.mask |= SD_BUS_CREDS_WELL_KNOWN_NAMES;
+                        }
                         break;
 
                 case KDBUS_ITEM_CONN_DESCRIPTION:
@@ -660,6 +674,29 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         m->creds.mask |= SD_BUS_CREDS_DESCRIPTION & bus->creds_mask;
                         break;
 
+                case KDBUS_ITEM_AUXGROUPS:
+
+                        if (bus->creds_mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS) {
+                                size_t i, n;
+                                uid_t *u;
+                                n = (d->size - offsetof(struct kdbus_item, data64)) / sizeof(uint64_t);
+                                u = new(uid_t, n);
+                                if (!u) {
+                                        r = -ENOMEM;
+                                        goto fail;
+                                }
+
+                                for (i = 0; i < n; i++)
+                                        u[i] = (uid_t) d->data64[i];
+
+                                m->creds.supplementary_gids = u;
+                                m->creds.n_supplementary_gids = n;
+
+                                m->creds.mask |= SD_BUS_CREDS_SUPPLEMENTARY_GIDS;
+                        }
+
+                        break;
+
                 case KDBUS_ITEM_FDS:
                 case KDBUS_ITEM_SECLABEL:
                         break;
@@ -874,13 +911,12 @@ int bus_kernel_connect(sd_bus *b) {
 }
 
 static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
-        struct kdbus_cmd_free cmd;
+        struct kdbus_cmd_free cmd = {};
         struct kdbus_item *d;
 
         assert(bus);
         assert(k);
 
-        cmd.flags = 0;
         cmd.offset = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;
 
         KDBUS_ITEM_FOREACH(d, k, items) {
@@ -1149,6 +1185,11 @@ int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
                 if (errno == EAGAIN)
                         return 0;
 
+                if (errno == EOVERFLOW) {
+                        log_debug("%s: kdbus reports %" PRIu64 " dropped broadcast messages, ignoring.", strna(bus->description), (uint64_t) recv.dropped_msgs);
+                        return 0;
+                }
+
                 return -errno;
         }
 
@@ -1272,11 +1313,9 @@ void bus_kernel_flush_memfd(sd_bus *b) {
                 close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].mapped);
 }
 
-int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) {
+uint64_t request_name_flags_to_kdbus(uint64_t flags) {
         uint64_t f = 0;
 
-        assert(kdbus_flags);
-
         if (flags & SD_BUS_NAME_ALLOW_REPLACEMENT)
                 f |= KDBUS_NAME_ALLOW_REPLACEMENT;
 
@@ -1286,15 +1325,12 @@ int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) {
         if (flags & SD_BUS_NAME_QUEUE)
                 f |= KDBUS_NAME_QUEUE;
 
-        *kdbus_flags = f;
-        return 0;
+        return f;
 }
 
-int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
+uint64_t attach_flags_to_kdbus(uint64_t mask) {
         uint64_t m = 0;
 
-        assert(kdbus_mask);
-
         if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_SUID|SD_BUS_CREDS_FSUID|
                     SD_BUS_CREDS_GID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SGID|SD_BUS_CREDS_FSGID))
                 m |= KDBUS_ATTACH_CREDS;
@@ -1332,8 +1368,10 @@ int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
         if (mask & SD_BUS_CREDS_DESCRIPTION)
                 m |= KDBUS_ATTACH_CONN_DESCRIPTION;
 
-        *kdbus_mask = m;
-        return 0;
+        if (mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS)
+                m |= KDBUS_ATTACH_AUXGROUPS;
+
+        return m;
 }
 
 int bus_kernel_create_bus(const char *name, bool world, char **s) {
@@ -1669,3 +1707,26 @@ int bus_kernel_drop_one(int fd) {
 
         return 0;
 }
+
+int bus_kernel_realize_attach_flags(sd_bus *bus) {
+        struct kdbus_cmd_update *update;
+        struct kdbus_item *n;
+
+        assert(bus);
+        assert(bus->is_kernel);
+
+        update = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_update, items) +
+                                      offsetof(struct kdbus_item, data64) + sizeof(uint64_t)), 8);
+
+        n = update->items;
+        n->type = KDBUS_ITEM_ATTACH_FLAGS_RECV;
+        n->size = offsetof(struct kdbus_item, data64) + sizeof(uint64_t);
+        n->data64[0] = bus->attach_flags;
+
+        update->size = offsetof(struct kdbus_cmd_update, items) + n->size;
+
+        if (ioctl(bus->input_fd, KDBUS_CMD_CONN_UPDATE, update) < 0)
+                return -errno;
+
+        return 0;
+}