sessiond: trigger: decouple reception of triggers from commands

[lttng-tools.git] / src / bin / lttng-sessiond / client.c

diff --git a/src/bin/lttng-sessiond/client.c b/src/bin/lttng-sessiond/client.c
index 3ccc29efceaf335a71ce0bc3c5d705aaefd90619..6c17ea2c1c24995a66439bcc2b3b60228c7fadcc 100644 (file)
--- a/src/bin/lttng-sessiond/client.c
+++ b/src/bin/lttng-sessiond/client.c
@@ -694,6 +694,77 @@ error:
        return ret;
 }
 
+static enum lttng_error_code receive_lttng_trigger(struct command_ctx *cmd_ctx,
+               int sock,
+               int *sock_error,
+               struct lttng_trigger **_trigger)
+{
+       int ret;
+       size_t trigger_len;
+       ssize_t sock_recv_len;
+       enum lttng_error_code ret_code;
+       struct lttng_payload trigger_payload;
+       struct lttng_trigger *trigger;
+
+       lttng_payload_init(&trigger_payload);
+       trigger_len = (size_t) cmd_ctx->lsm.u.trigger.length;
+       ret = lttng_dynamic_buffer_set_size(
+                       &trigger_payload.buffer, trigger_len);
+       if (ret) {
+               ret_code = LTTNG_ERR_NOMEM;
+               goto end;
+       }
+
+       sock_recv_len = lttcomm_recv_unix_sock(
+                       sock, trigger_payload.buffer.data, trigger_len);
+       if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
+               ERR("Failed to receive trigger in command payload");
+               *sock_error = 1;
+               ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+               goto end;
+       }
+
+       /* Receive fds, if any. */
+       if (cmd_ctx->lsm.fd_count > 0) {
+               sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
+                               sock, cmd_ctx->lsm.fd_count, &trigger_payload);
+               if (sock_recv_len > 0 &&
+                               sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
+                       ERR("Failed to receive all file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
+                                       cmd_ctx->lsm.fd_count, (int) ret);
+                       ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+                       *sock_error = 1;
+                       goto end;
+               } else if (sock_recv_len <= 0) {
+                       ERR("Failed to receive file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
+                                       cmd_ctx->lsm.fd_count, (int) ret);
+                       ret_code = LTTNG_ERR_FATAL;
+                       *sock_error = 1;
+                       goto end;
+               }
+       }
+
+       /* Deserialize trigger. */
+       {
+               struct lttng_payload_view view =
+                               lttng_payload_view_from_payload(
+                                               &trigger_payload, 0, -1);
+
+               if (lttng_trigger_create_from_payload(&view, &trigger) !=
+                               trigger_len) {
+                       ERR("Invalid trigger received as part of command payload");
+                       ret_code = LTTNG_ERR_INVALID_TRIGGER;
+                       goto end;
+               }
+       }
+
+       *_trigger = trigger;
+       ret_code = LTTNG_OK;
+
+end:
+       return ret_code;
+}
+
 /*
  * Version of setup_lttng_msg() without command header.
  */
@@ -2055,9 +2126,14 @@ error_add_context:
        }
        case LTTNG_REGISTER_TRIGGER:
        {
+               struct lttng_trigger *payload_trigger;
                struct lttng_trigger *return_trigger;
-               size_t original_payload_size;
-               size_t payload_size;
+               size_t original_reply_payload_size;
+               size_t reply_payload_size;
+               const struct lttng_credentials cmd_creds = {
+                       .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
+                       .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
+               };
 
                ret = setup_empty_lttng_msg(cmd_ctx);
                if (ret) {
@@ -2065,37 +2141,55 @@ error_add_context:
                        goto setup_error;
                }
 
-               original_payload_size = cmd_ctx->reply_payload.buffer.size;
+               ret = receive_lttng_trigger(
+                               cmd_ctx, *sock, sock_error, &payload_trigger);
+               if (ret != LTTNG_OK) {
+                       goto error;
+               }
 
-               ret = cmd_register_trigger(cmd_ctx, *sock,
+               original_reply_payload_size = cmd_ctx->reply_payload.buffer.size;
+
+               ret = cmd_register_trigger(&cmd_creds, payload_trigger,
                                notification_thread_handle, &return_trigger);
                if (ret != LTTNG_OK) {
+                       lttng_trigger_put(payload_trigger);
                        goto error;
                }
 
                ret = lttng_trigger_serialize(return_trigger, &cmd_ctx->reply_payload);
+               lttng_trigger_put(payload_trigger);
+               lttng_trigger_put(return_trigger);
                if (ret) {
                        ERR("Failed to serialize trigger in reply to \"register trigger\" command");
                        ret = LTTNG_ERR_NOMEM;
-                       lttng_trigger_destroy(return_trigger);
                        goto error;
                }
 
-               lttng_trigger_destroy(return_trigger);
-               return_trigger = NULL;
-
-               payload_size = cmd_ctx->reply_payload.buffer.size -
-                       original_payload_size;
+               reply_payload_size = cmd_ctx->reply_payload.buffer.size -
+                       original_reply_payload_size;
 
-               update_lttng_msg(cmd_ctx, 0, payload_size);
+               update_lttng_msg(cmd_ctx, 0, reply_payload_size);
 
                ret = LTTNG_OK;
                break;
        }
        case LTTNG_UNREGISTER_TRIGGER:
        {
-               ret = cmd_unregister_trigger(cmd_ctx, *sock,
+               struct lttng_trigger *payload_trigger;
+               const struct lttng_credentials cmd_creds = {
+                       .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
+                       .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
+               };
+
+               ret = receive_lttng_trigger(
+                               cmd_ctx, *sock, sock_error, &payload_trigger);
+               if (ret != LTTNG_OK) {
+                       goto error;
+               }
+
+               ret = cmd_unregister_trigger(&cmd_creds, payload_trigger,
                                notification_thread_handle);
+               lttng_trigger_put(payload_trigger);
                break;
        }
        case LTTNG_ROTATE_SESSION: