chiark / gitweb /
nspawn: set up a kdbus namespace when starting a container
[elogind.git] / src / libsystemd-bus / bus-kernel.c
index 1b54ba5d5b6fef4c55fd2156f3fbe6211a07eec2..09e084a02f17f31dd652082ca39a96319f4184d1 100644 (file)
@@ -356,6 +356,8 @@ int bus_kernel_take_fd(sd_bus *b) {
         if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello.id) < 0)
                 return -ENOMEM;
 
+        b->unique_id = hello.id;
+
         b->is_kernel = true;
         b->bus_client = true;
         b->can_fds = !!(hello.conn_flags & KDBUS_HELLO_ACCEPT_FD);
@@ -363,11 +365,7 @@ int bus_kernel_take_fd(sd_bus *b) {
         /* the kernel told us the UUID of the underlying bus */
         memcpy(b->server_id.bytes, hello.id128, sizeof(b->server_id.bytes));
 
-        r = bus_start_running(b);
-        if (r < 0)
-                return r;
-
-        return 1;
+        return bus_start_running(b);
 }
 
 int bus_kernel_connect(sd_bus *b) {
@@ -395,13 +393,60 @@ int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) {
         assert(m);
         assert(bus->state == BUS_RUNNING);
 
+        /* If we can't deliver, we want room for the error message */
+        r = bus_rqueue_make_room(bus);
+        if (r < 0)
+                return r;
+
         r = bus_message_setup_kmsg(bus, m);
         if (r < 0)
                 return r;
 
         r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
-        if (r < 0)
-                return errno == EAGAIN ? 0 : -errno;
+        if (r < 0) {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus_message *reply;
+
+                if (errno == EAGAIN || errno == EINTR)
+                        return 0;
+                else if (errno == ENXIO || errno == ESRCH) {
+
+                        /* ENXIO: unique name not known
+                         * ESRCH: well-known name not known */
+
+                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination);
+                        else
+                                return 0;
+
+                } else if (errno == EADDRNOTAVAIL) {
+
+                        /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */
+
+                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination);
+                        else
+                                return 0;
+                } else
+                        return -errno;
+
+                r = bus_message_new_synthetic_error(
+                                bus,
+                                BUS_MESSAGE_SERIAL(m),
+                                &error,
+                                &reply);
+
+                if (r < 0)
+                        return r;
+
+                r = bus_seal_synthetic_message(bus, reply);
+                if (r < 0)
+                        return r;
+
+                bus->rqueue[bus->rqueue_size++] = reply;
+
+                return 0;
+        }
 
         return 1;
 }
@@ -414,7 +459,7 @@ static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
         assert(k);
 
         off = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;
-        ioctl(bus->input_fd, KDBUS_CMD_MSG_RELEASE, &off);
+        ioctl(bus->input_fd, KDBUS_CMD_FREE, &off);
 
         KDBUS_PART_FOREACH(d, k, items) {
 
@@ -425,12 +470,11 @@ static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
         }
 }
 
-static int return_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner, sd_bus_message **ret) {
+static int push_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner) {
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
         int r;
 
         assert(bus);
-        assert(ret);
 
         r = sd_bus_message_new_signal(
                         bus,
@@ -447,23 +491,22 @@ static int return_name_owner_changed(sd_bus *bus, const char *name, const char *
 
         m->sender = "org.freedesktop.DBus";
 
-        r = bus_seal_message(bus, m);
+        r = bus_seal_synthetic_message(bus, m);
         if (r < 0)
                 return r;
 
-        *ret = m;
+        bus->rqueue[bus->rqueue_size++] = m;
         m = NULL;
 
         return 1;
 }
 
-static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d, sd_bus_message **ret) {
+static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
         char new_owner[UNIQUE_NAME_MAX], old_owner[UNIQUE_NAME_MAX];
 
         assert(bus);
         assert(k);
         assert(d);
-        assert(ret);
 
         if (d->name_change.flags != 0)
                 return 0;
@@ -478,34 +521,31 @@ static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_
         else
                 sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new_id);
 
-        return return_name_owner_changed(bus, d->name_change.name, old_owner, new_owner, ret);
+        return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner);
 }
 
-static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d, sd_bus_message **ret) {
+static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
         char owner[UNIQUE_NAME_MAX];
 
         assert(bus);
         assert(k);
         assert(d);
-        assert(ret);
 
         sprintf(owner, ":1.%llu", d->id_change.id);
 
-        return return_name_owner_changed(
+        return push_name_owner_changed(
                         bus, owner,
                         d->type == KDBUS_ITEM_ID_ADD ? NULL : owner,
-                        d->type == KDBUS_ITEM_ID_ADD ? owner : NULL,
-                        ret);
+                        d->type == KDBUS_ITEM_ID_ADD ? owner : NULL);
 }
 
-static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d, sd_bus_message **ret) {
+static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
         int r;
 
         assert(bus);
         assert(k);
         assert(d);
-        assert(ret);
 
         r = bus_message_new_synthetic_error(
                         bus,
@@ -519,20 +559,20 @@ static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *
 
         m->sender = "org.freedesktop.DBus";
 
-        r = bus_seal_message(bus, m);
+        r = bus_seal_synthetic_message(bus, m);
         if (r < 0)
                 return r;
 
-        *ret = m;
+        bus->rqueue[bus->rqueue_size++] = m;
         m = NULL;
 
         return 1;
 }
 
-static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_message **ret) {
+static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
         struct kdbus_item *d, *found = NULL;
 
-        static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d, sd_bus_message **ret) = {
+        static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) = {
                 [KDBUS_ITEM_NAME_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
                 [KDBUS_ITEM_NAME_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
                 [KDBUS_ITEM_NAME_CHANGE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
@@ -546,7 +586,6 @@ static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k, sd_bus
 
         assert(bus);
         assert(k);
-        assert(ret);
         assert(k->payload_type == KDBUS_PAYLOAD_KERNEL);
 
         KDBUS_PART_FOREACH(d, k, items) {
@@ -563,43 +602,10 @@ static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k, sd_bus
                 return 0;
         }
 
-        return translate[found->type](bus, k, d, ret);
-}
-
-int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
-
-        uint64_t m = 0;
-
-        SET_FLAG(m, KDBUS_ATTACH_CREDS,
-                 !!(mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID)));
-
-        SET_FLAG(m, KDBUS_ATTACH_COMM,
-                 !!(mask & (SD_BUS_CREDS_COMM|SD_BUS_CREDS_TID_COMM)));
-
-        SET_FLAG(m, KDBUS_ATTACH_EXE,
-                 !!(mask & SD_BUS_CREDS_EXE));
-
-        SET_FLAG(m, KDBUS_ATTACH_CMDLINE,
-                 !!(mask & SD_BUS_CREDS_CMDLINE));
-
-        SET_FLAG(m, KDBUS_ATTACH_CGROUP,
-                 !!(mask & (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID)));
-
-        SET_FLAG(m, KDBUS_ATTACH_CAPS,
-                 !!(mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS)));
-
-        SET_FLAG(m, KDBUS_ATTACH_SECLABEL,
-                 !!(mask & SD_BUS_CREDS_SELINUX_CONTEXT));
-
-        SET_FLAG(m, KDBUS_ATTACH_AUDIT,
-                 !!(mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID)));
-
-        *kdbus_mask = m;
-
-        return 0;
+        return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found);
 }
 
-static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_message **ret) {
+static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
         sd_bus_message *m = NULL;
         struct kdbus_item *d;
         unsigned n_fds = 0;
@@ -611,7 +617,6 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
 
         assert(bus);
         assert(k);
-        assert(ret);
         assert(k->payload_type == KDBUS_PAYLOAD_DBUS1);
 
         KDBUS_PART_FOREACH(d, k, items) {
@@ -770,7 +775,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
 
                 case KDBUS_ITEM_CMDLINE:
                         m->creds.cmdline = d->str;
-                        m->creds.cmdline_length = l;
+                        m->creds.cmdline_size = l;
                         m->creds.mask |= SD_BUS_CREDS_CMDLINE & bus->creds_mask;
                         break;
 
@@ -795,9 +800,14 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                         destination = d->str;
                         break;
 
+                case KDBUS_ITEM_NAMES:
+                        m->creds.well_known_names = d->str;
+                        m->creds.well_known_names_size = l;
+                        m->creds.mask |= SD_BUS_CREDS_WELL_KNOWN_NAMES & bus->creds_mask;
+                        break;
+
                 case KDBUS_ITEM_FDS:
                 case KDBUS_ITEM_SECLABEL:
-                case KDBUS_ITEM_NAMES:
                         break;
 
                 default:
@@ -813,7 +823,8 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                 m->sender = "org.freedesktop.DBus";
         else {
                 snprintf(m->sender_buffer, sizeof(m->sender_buffer), ":1.%llu", (unsigned long long) k->src_id);
-                m->sender = m->sender_buffer;
+                m->sender = m->creds.unique_name = m->sender_buffer;
+                m->creds.mask |= SD_BUS_CREDS_UNIQUE_NAME & bus->creds_mask;
         }
 
         if (!m->destination) {
@@ -830,10 +841,10 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
         m->kdbus = k;
         m->release_kdbus = true;
         m->free_fds = true;
-
         fds = NULL;
 
-        *ret = m;
+        bus->rqueue[bus->rqueue_size++] = m;
+
         return 1;
 
 fail:
@@ -852,13 +863,16 @@ fail:
         return r;
 }
 
-int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
-        uint64_t off;
+int bus_kernel_read_message(sd_bus *bus) {
         struct kdbus_msg *k;
+        uint64_t off;
         int r;
 
         assert(bus);
-        assert(m);
+
+        r = bus_rqueue_make_room(bus);
+        if (r < 0)
+                return r;
 
         r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, &off);
         if (r < 0) {
@@ -870,9 +884,9 @@ int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
         k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + off);
 
         if (k->payload_type == KDBUS_PAYLOAD_DBUS1)
-                r = bus_kernel_make_message(bus, k, m);
+                r = bus_kernel_make_message(bus, k);
         else if (k->payload_type == KDBUS_PAYLOAD_KERNEL)
-                r = bus_kernel_translate_message(bus, k, m);
+                r = bus_kernel_translate_message(bus, k);
         else
                 r = 0;
 
@@ -882,52 +896,6 @@ int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
         return r < 0 ? r : 1;
 }
 
-int bus_kernel_create(const char *name, char **s) {
-        struct kdbus_cmd_bus_make *make;
-        struct kdbus_item *n;
-        size_t l;
-        int fd;
-        char *p;
-
-        assert(name);
-        assert(s);
-
-        fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
-        if (fd < 0)
-                return -errno;
-
-        l = strlen(name);
-        make = alloca0(offsetof(struct kdbus_cmd_bus_make, items) +
-                       KDBUS_PART_HEADER_SIZE + sizeof(uint64_t) +
-                       KDBUS_PART_HEADER_SIZE + DECIMAL_STR_MAX(uid_t) + 1 + l + 1);
-
-        n = make->items;
-        n->type = KDBUS_MAKE_NAME;
-        sprintf(n->str, "%lu-%s", (unsigned long) getuid(), name);
-        n->size = KDBUS_PART_HEADER_SIZE + strlen(n->str) + 1;
-
-        make->size = offsetof(struct kdbus_cmd_bus_make, items) + n->size;
-        make->flags = KDBUS_MAKE_POLICY_OPEN;
-        make->bus_flags = 0;
-        make->bloom_size = BLOOM_SIZE;
-        assert_cc(BLOOM_SIZE % 8 == 0);
-
-        p = strjoin("/dev/kdbus/", n->str, "/bus", NULL);
-        if (!p)
-                return -ENOMEM;
-
-        if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) {
-                close_nointr_nofail(fd);
-                free(p);
-                return -errno;
-        }
-
-        if (s)
-                *s = p;
-
-        return fd;
-}
-
 int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *size) {
         struct memfd_cache *c;
         int fd;
@@ -1020,20 +988,147 @@ 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].size);
 }
 
-int sd_bus_kernel_translate_request_name_flags(uint64_t sd_bus_flags, uint64_t *kdbus_flags) {
+int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) {
+        uint64_t f = 0;
+
+        assert(kdbus_flags);
+
+        if (flags & SD_BUS_NAME_ALLOW_REPLACEMENT)
+                f |= KDBUS_NAME_ALLOW_REPLACEMENT;
+
+        if (flags & SD_BUS_NAME_REPLACE_EXISTING)
+                f |= KDBUS_NAME_REPLACE_EXISTING;
+
+        if (!(flags & SD_BUS_NAME_DO_NOT_QUEUE))
+                f |= KDBUS_NAME_QUEUE;
+
+        *kdbus_flags = f;
+        return 0;
+}
+
+int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
+        uint64_t m = 0;
+
+        assert(kdbus_mask);
 
-        assert_return(kdbus_flags != NULL, -EINVAL);
+        if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID))
+                m |= KDBUS_ATTACH_CREDS;
 
-        *kdbus_flags = 0;
+        if (mask & (SD_BUS_CREDS_COMM|SD_BUS_CREDS_TID_COMM))
+                m |= KDBUS_ATTACH_COMM;
 
-        if (sd_bus_flags & SD_BUS_NAME_ALLOW_REPLACEMENT)
-                *kdbus_flags |= KDBUS_NAME_ALLOW_REPLACEMENT;
+        if (mask & SD_BUS_CREDS_EXE)
+                m |= KDBUS_ATTACH_EXE;
 
-        if (sd_bus_flags & SD_BUS_NAME_REPLACE_EXISTING)
-                *kdbus_flags |= KDBUS_NAME_REPLACE_EXISTING;
+        if (mask & SD_BUS_CREDS_CMDLINE)
+                m |= KDBUS_ATTACH_CMDLINE;
 
-        if (!(sd_bus_flags & SD_BUS_NAME_DO_NOT_QUEUE))
-                *kdbus_flags |= KDBUS_NAME_QUEUE;
+        if (mask & (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID))
+                m |= KDBUS_ATTACH_CGROUP;
 
+        if (mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS))
+                m |= KDBUS_ATTACH_CAPS;
+
+        if (mask & SD_BUS_CREDS_SELINUX_CONTEXT)
+                m |= KDBUS_ATTACH_SECLABEL;
+
+        if (mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID))
+                m |= KDBUS_ATTACH_AUDIT;
+
+        if (mask & SD_BUS_CREDS_WELL_KNOWN_NAMES)
+                m |= KDBUS_ATTACH_NAMES;
+
+        *kdbus_mask = m;
         return 0;
 }
+
+int bus_kernel_create_bus(const char *name, char **s) {
+        struct kdbus_cmd_bus_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(ALIGN8(offsetof(struct kdbus_cmd_bus_make, items) +
+                              offsetof(struct kdbus_item, str) +
+                              DECIMAL_STR_MAX(uid_t) + 1 + strlen(name) + 1));
+
+        n = make->items;
+        sprintf(n->str, "%lu-%s", (unsigned long) getuid(), name);
+        n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
+        n->type = KDBUS_MAKE_NAME;
+
+        make->size = ALIGN8(offsetof(struct kdbus_cmd_bus_make, items) + n->size);
+        make->flags = KDBUS_MAKE_POLICY_OPEN;
+        make->bus_flags = 0;
+        make->bloom_size = BLOOM_SIZE;
+        assert_cc(BLOOM_SIZE % 8 == 0);
+
+        if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) {
+                close_nointr_nofail(fd);
+                return -errno;
+        }
+
+        if (s) {
+                char *p;
+
+                p = strjoin("/dev/kdbus/", n->str, "/bus", NULL);
+                if (!p) {
+                        close_nointr_nofail(fd);
+                        return -ENOMEM;
+                }
+
+                *s = p;
+        }
+
+        return fd;
+}
+
+int bus_kernel_create_namespace(const char *name, char **s) {
+        struct kdbus_cmd_ns_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(ALIGN8(offsetof(struct kdbus_cmd_ns_make, items) +
+                              offsetof(struct kdbus_item, str) +
+                              strlen(name) + 1));
+
+        n = make->items;
+        strcpy(n->str, name);
+        n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
+        n->type = KDBUS_MAKE_NAME;
+
+        make->size = ALIGN8(offsetof(struct kdbus_cmd_ns_make, items) + n->size);
+        make->flags = KDBUS_MAKE_POLICY_OPEN;
+
+        if (ioctl(fd, KDBUS_CMD_NS_MAKE, make) < 0) {
+                close_nointr_nofail(fd);
+                return -errno;
+        }
+
+        if (s) {
+                char *p;
+
+                p = strappend("/dev/kdbus/", name);
+                if (!p) {
+                        close_nointr_nofail(fd);
+                        return -ENOMEM;
+                }
+
+                *s = p;
+        }
+
+        return fd;
+}