Fix: liblttng-ctl comm: lttng_event_field is not packed

[lttng-tools.git] / src / lib / lttng-ctl / lttng-ctl.c

diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index a387202a66e1d192cfa7b586553164ab01d94d8c..fd5d9e3d66eb9dbddbafa8490da95cf1ab5f21d5 100644 (file)
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -1652,8 +1652,13 @@ end:
 int lttng_list_tracepoint_fields(struct lttng_handle *handle,
                struct lttng_event_field **fields)
 {
-       int ret;
+       enum lttng_error_code ret_code;
+       int ret, total_payload_received;
        struct lttcomm_session_msg lsm;
+       char *reception_buffer = NULL;
+       struct lttcomm_list_command_header *cmd_header = NULL;
+       size_t cmd_header_len;
+       unsigned int nb_event_fields = 0;
 
        if (handle == NULL) {
                return -LTTNG_ERR_INVALID;
@@ -1663,12 +1668,45 @@ int lttng_list_tracepoint_fields(struct lttng_handle *handle,
        lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
        COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
 
-       ret = lttng_ctl_ask_sessiond(&lsm, (void **) fields);
+       ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm, NULL, 0, NULL, 0,
+                       (void **) &reception_buffer, (void **) &cmd_header,
+                       &cmd_header_len);
        if (ret < 0) {
-               return ret;
+               goto end;
        }
 
-       return ret / sizeof(struct lttng_event_field);
+       total_payload_received = ret;
+
+       if (!cmd_header) {
+               ret = -LTTNG_ERR_UNK;
+               goto end;
+       }
+
+       if (cmd_header->count > INT_MAX) {
+               ret = -LTTNG_ERR_OVERFLOW;
+               goto end;
+       }
+
+       nb_event_fields = cmd_header->count;
+
+       {
+               const struct lttng_buffer_view view =
+                       lttng_buffer_view_init(reception_buffer, 0, total_payload_received);
+
+               ret_code = lttng_event_fields_create_and_flatten_from_buffer(
+                               &view, nb_event_fields, fields);
+               if (ret_code != LTTNG_OK) {
+                       ret = -ret_code;
+                       goto end;
+               }
+       }
+
+       ret = nb_event_fields;
+
+end:
+       free(cmd_header);
+       free(reception_buffer);
+       return ret;
 }
 
 /*