chiark / gitweb /
sd-bus: react properly to EOVERFLOW by generating a log message about dropped broadca...
[elogind.git] / src / libsystemd / sd-bus / bus-kernel.c
index 142eb91c64b60c5fcac33d12ddd3e013db0544eb..e03e4471cec11e2dd15dbe47747bc19ce3f3139f 100644 (file)
@@ -204,6 +204,7 @@ static int bus_message_setup_bloom(sd_bus_message *m, struct kdbus_bloom_filter
 static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         struct bus_body_part *part;
         struct kdbus_item *d;
+        const char *destination;
         bool well_known;
         uint64_t unique;
         size_t sz, dl;
@@ -219,8 +220,10 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         if (m->kdbus)
                 return 0;
 
-        if (m->destination) {
-                r = bus_kernel_parse_unique_name(m->destination, &unique);
+        destination = m->destination ?: m->destination_ptr;
+
+        if (destination) {
+                r = bus_kernel_parse_unique_name(destination, &unique);
                 if (r < 0)
                         return r;
 
@@ -244,7 +247,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
 
         /* Add in well-known destination header */
         if (well_known) {
-                dl = strlen(m->destination);
+                dl = strlen(destination);
                 sz += ALIGN8(offsetof(struct kdbus_item, str) + dl + 1);
         }
 
@@ -264,9 +267,17 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         m->kdbus->flags =
                 ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |
                 ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);
-        m->kdbus->dst_id =
-                well_known ? 0 :
-                m->destination ? unique : KDBUS_DST_ID_BROADCAST;
+
+        if (well_known) {
+                /* verify_destination_id will usually be 0, which makes the kernel driver only look
+                 * at the provided well-known name. Otherwise, the kernel will make sure the provided
+                 * destination id matches the owner of the provided weel-known-name, and fail if they
+                 * differ. Currently, this is only needed for bus-proxyd. */
+                m->kdbus->dst_id = m->verify_destination_id;
+        } else {
+                m->kdbus->dst_id = destination ? unique : KDBUS_DST_ID_BROADCAST;
+        }
+
         m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS;
         m->kdbus->cookie = (uint64_t) m->header->serial;
         m->kdbus->priority = m->priority;
@@ -284,7 +295,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         d = m->kdbus->items;
 
         if (well_known)
-                append_destination(&d, m->destination, dl);
+                append_destination(&d, destination, dl);
 
         append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m));
 
@@ -299,7 +310,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
                         continue;
                 }
 
-                if (part->memfd >= 0 && part->sealed && m->destination) {
+                if (part->memfd >= 0 && part->sealed && destination) {
                         /* Try to send a memfd, if the part is
                          * sealed and this is not a broadcast. Since we can only  */
 
@@ -502,28 +513,75 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         break;
                 }
 
-                case KDBUS_ITEM_CREDS:
-                        /* UID/GID/PID are always valid */
-                        m->creds.uid = (uid_t) d->creds.uid;
-                        m->creds.gid = (gid_t) d->creds.gid;
-                        m->creds.pid = (pid_t) d->creds.pid;
-                        m->creds.mask |= (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID) & bus->creds_mask;
-
-                        /* The PID starttime/TID might be missing
-                         * however, when the data is faked by some
-                         * data bus proxy and it lacks that
-                         * information about the real client since
-                         * SO_PEERCRED is used for that */
-
-                        if (d->creds.starttime > 0) {
-                                m->creds.pid_starttime = d->creds.starttime / NSEC_PER_USEC;
+                case KDBUS_ITEM_PIDS:
+
+                        /* The PID starttime/TID might be missing,
+                         * when the data is faked by some data bus
+                         * proxy and it lacks that information about
+                         * the real client since SO_PEERCRED is used
+                         * for that. */
+
+                        if (d->pids.pid > 0) {
+                                m->creds.pid = (pid_t) d->pids.pid;
+                                m->creds.mask |= SD_BUS_CREDS_PID & bus->creds_mask;
+                        }
+
+                        if (d->pids.starttime > 0) {
+                                m->creds.pid_starttime = d->pids.starttime / NSEC_PER_USEC;
                                 m->creds.mask |= SD_BUS_CREDS_PID_STARTTIME & bus->creds_mask;
                         }
 
-                        if (d->creds.tid > 0) {
-                                m->creds.tid = (pid_t) d->creds.tid;
+                        if (d->pids.tid > 0) {
+                                m->creds.tid = (pid_t) d->pids.tid;
                                 m->creds.mask |= SD_BUS_CREDS_TID & bus->creds_mask;
                         }
+
+                        break;
+
+                case KDBUS_ITEM_CREDS:
+
+                        /* EUID/SUID/FSUID/EGID/SGID/FSGID might be missing too (see above). */
+
+                        if ((uid_t) d->creds.uid != (uid_t) -1) {
+                                m->creds.uid = (uid_t) d->creds.uid;
+                                m->creds.mask |= SD_BUS_CREDS_UID & bus->creds_mask;
+                        }
+
+                        if ((uid_t) d->creds.euid != (uid_t) -1) {
+                                m->creds.euid = (uid_t) d->creds.euid;
+                                m->creds.mask |= SD_BUS_CREDS_EUID & bus->creds_mask;
+                        }
+
+                        if ((uid_t) d->creds.suid != (uid_t) -1) {
+                                m->creds.suid = (uid_t) d->creds.suid;
+                                m->creds.mask |= SD_BUS_CREDS_SUID & bus->creds_mask;
+                        }
+
+                        if ((uid_t) d->creds.fsuid != (uid_t) -1) {
+                                m->creds.fsuid = (uid_t) d->creds.fsuid;
+                                m->creds.mask |= SD_BUS_CREDS_FSUID & bus->creds_mask;
+                        }
+
+                        if ((gid_t) d->creds.gid != (gid_t) -1) {
+                                m->creds.gid = (gid_t) d->creds.gid;
+                                m->creds.mask |= SD_BUS_CREDS_GID & bus->creds_mask;
+                        }
+
+                        if ((gid_t) d->creds.egid != (gid_t) -1) {
+                                m->creds.egid = (gid_t) d->creds.egid;
+                                m->creds.mask |= SD_BUS_CREDS_EGID & bus->creds_mask;
+                        }
+
+                        if ((gid_t) d->creds.sgid != (gid_t) -1) {
+                                m->creds.sgid = (gid_t) d->creds.sgid;
+                                m->creds.mask |= SD_BUS_CREDS_SGID & bus->creds_mask;
+                        }
+
+                        if ((gid_t) d->creds.fsgid != (gid_t) -1) {
+                                m->creds.fsgid = (gid_t) d->creds.fsgid;
+                                m->creds.mask |= SD_BUS_CREDS_FSGID & bus->creds_mask;
+                        }
+
                         break;
 
                 case KDBUS_ITEM_TIMESTAMP:
@@ -570,9 +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:
@@ -582,19 +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:
@@ -602,6 +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;
@@ -713,6 +808,9 @@ int bus_kernel_take_fd(sd_bus *b) {
         if (b->fake_creds_valid)
                 sz += ALIGN8(offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds));
 
+        if (b->fake_pids_valid)
+                sz += ALIGN8(offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids));
+
         if (b->fake_label) {
                 l = strlen(b->fake_label);
                 sz += ALIGN8(offsetof(struct kdbus_item, str) + l + 1);
@@ -721,7 +819,7 @@ int bus_kernel_take_fd(sd_bus *b) {
         hello = alloca0_align(sz, 8);
         hello->size = sz;
         hello->flags = b->hello_flags;
-        hello->attach_flags_send = _KDBUS_ATTACH_ALL;
+        hello->attach_flags_send = _KDBUS_ATTACH_ANY;
         hello->attach_flags_recv = b->attach_flags;
         hello->pool_size = KDBUS_POOL_SIZE;
 
@@ -740,6 +838,14 @@ int bus_kernel_take_fd(sd_bus *b) {
                 item = KDBUS_ITEM_NEXT(item);
         }
 
+        if (b->fake_pids_valid) {
+                item->size = offsetof(struct kdbus_item, pids) + sizeof(struct kdbus_pids);
+                item->type = KDBUS_ITEM_PIDS;
+                item->pids = b->fake_pids;
+
+                item = KDBUS_ITEM_NEXT(item);
+        }
+
         if (b->fake_label) {
                 item->size = offsetof(struct kdbus_item, str) + l + 1;
                 item->type = KDBUS_ITEM_SECLABEL;
@@ -805,13 +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) {
@@ -1080,6 +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;
         }
 
@@ -1226,9 +1336,13 @@ int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
 
         assert(kdbus_mask);
 
-        if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID))
+        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;
 
+        if (mask & (SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID))
+                m |= KDBUS_ATTACH_PIDS;
+
         if (mask & SD_BUS_CREDS_COMM)
                 m |= KDBUS_ATTACH_PID_COMM;
 
@@ -1259,6 +1373,9 @@ int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
         if (mask & SD_BUS_CREDS_DESCRIPTION)
                 m |= KDBUS_ATTACH_CONN_DESCRIPTION;
 
+        if (mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS)
+                m |= KDBUS_ATTACH_AUXGROUPS;
+
         *kdbus_mask = m;
         return 0;
 }
@@ -1271,7 +1388,7 @@ int bus_kernel_create_bus(const char *name, bool world, char **s) {
         assert(name);
         assert(s);
 
-        fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
+        fd = open("/sys/fs/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (fd < 0)
                 return -errno;
 
@@ -1312,7 +1429,7 @@ int bus_kernel_create_bus(const char *name, bool world, char **s) {
         if (s) {
                 char *p;
 
-                p = strjoin("/dev/kdbus/", n->str, "/bus", NULL);
+                p = strjoin("/sys/fs/kdbus/", n->str, "/bus", NULL);
                 if (!p) {
                         safe_close(fd);
                         return -ENOMEM;
@@ -1392,7 +1509,7 @@ int bus_kernel_open_bus_fd(const char *bus, char **path) {
         int fd;
         size_t len;
 
-        len = strlen("/dev/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
+        len = strlen("/sys/fs/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
 
         if (path) {
                 p = malloc(len);
@@ -1401,7 +1518,7 @@ int bus_kernel_open_bus_fd(const char *bus, char **path) {
                 *path = p;
         } else
                 p = alloca(len);
-        sprintf(p, "/dev/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
+        sprintf(p, "/sys/fs/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
 
         fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (fd < 0)
@@ -1557,7 +1674,7 @@ int bus_kernel_make_starter(
                 (activating ? KDBUS_HELLO_ACTIVATOR : KDBUS_HELLO_POLICY_HOLDER) |
                 (accept_fd ? KDBUS_HELLO_ACCEPT_FD : 0);
         hello->pool_size = KDBUS_POOL_SIZE;
-        hello->attach_flags_send = _KDBUS_ATTACH_ALL;
+        hello->attach_flags_send = _KDBUS_ATTACH_ANY;
         hello->attach_flags_recv = _KDBUS_ATTACH_ALL;
 
         if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0)
@@ -1574,58 +1691,6 @@ int bus_kernel_make_starter(
         return fd;
 }
 
-int bus_kernel_create_domain(const char *name, char **s) {
-        struct kdbus_cmd_make *make;
-        struct kdbus_item *n;
-        int fd;
-
-        assert(name);
-        assert(s);
-
-        fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
-        if (fd < 0)
-                return -errno;
-
-        make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items) +
-                                    offsetof(struct kdbus_item, str) +
-                                    strlen(name) + 1),
-                             8);
-
-        n = make->items;
-        strcpy(n->str, name);
-        n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
-        n->type = KDBUS_ITEM_MAKE_NAME;
-
-        make->size = ALIGN8(offsetof(struct kdbus_cmd_make, items) + n->size);
-        make->flags = KDBUS_MAKE_ACCESS_WORLD;
-
-        if (ioctl(fd, KDBUS_CMD_DOMAIN_MAKE, make) < 0) {
-                safe_close(fd);
-                return -errno;
-        }
-
-        /* The higher 32bit of the flags field are considered
-         * 'incompatible flags'. Refuse them all for now. */
-        if (make->flags > 0xFFFFFFFFULL) {
-                safe_close(fd);
-                return -ENOTSUP;
-        }
-
-        if (s) {
-                char *p;
-
-                p = strappend("/dev/kdbus/domain/", name);
-                if (!p) {
-                        safe_close(fd);
-                        return -ENOMEM;
-                }
-
-                *s = p;
-        }
-
-        return fd;
-}
-
 int bus_kernel_try_close(sd_bus *bus) {
         assert(bus);
         assert(bus->is_kernel);