Fix: liblttng-ctl comm: lttng_event_field is not packed

[lttng-tools.git] / src / bin / lttng-sessiond / cmd.cpp

diff --git a/src/bin/lttng-sessiond/cmd.cpp b/src/bin/lttng-sessiond/cmd.cpp
index a9efd88be9a954cd8ef2882133e3749d4a2afdb9..0627ba5c8bd5f83ca62d9403cddea283a2ce6f8f 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.cpp
+++ b/src/bin/lttng-sessiond/cmd.cpp
@@ -1864,27 +1864,24 @@ error:
 /*
  * Command LTTNG_ADD_CONTEXT processed by the client thread.
  */
-int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
-               char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
+int cmd_add_context(struct command_ctx *cmd_ctx,
+       const struct lttng_event_context *event_context, int kwpipe)
 {
        int ret, chan_kern_created = 0, chan_ust_created = 0;
-       char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
+       const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
+       const struct ltt_session *session = cmd_ctx->session;
+       const char *channel_name = cmd_ctx->lsm.u.context.channel_name;
 
        /*
         * Don't try to add a context if the session has been started at
         * some point in time before. The tracer does not allow it and would
         * result in a corrupted trace.
         */
-       if (session->has_been_started) {
+       if (cmd_ctx->session->has_been_started) {
                ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
                goto end;
        }
 
-       if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
-               app_ctx_provider_name = ctx->u.app_ctx.provider_name;
-               app_ctx_name = ctx->u.app_ctx.ctx_name;
-       }
-
        switch (domain) {
        case LTTNG_DOMAIN_KERNEL:
                LTTNG_ASSERT(session->kernel_session);
@@ -1898,7 +1895,8 @@ int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
                        chan_kern_created = 1;
                }
                /* Add kernel context to kernel tracer */
-               ret = context_kernel_add(session->kernel_session, ctx, channel_name);
+               ret = context_kernel_add(session->kernel_session,
+                               event_context, channel_name);
                if (ret != LTTNG_OK) {
                        goto error;
                }
@@ -1952,11 +1950,8 @@ int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
                        chan_ust_created = 1;
                }
 
-               ret = context_ust_add(usess, domain, ctx, channel_name);
-               free(app_ctx_provider_name);
-               free(app_ctx_name);
-               app_ctx_name = NULL;
-               app_ctx_provider_name = NULL;
+               ret = context_ust_add(usess, domain, event_context,
+                               channel_name);
                if (ret != LTTNG_OK) {
                        goto error;
                }
@@ -1993,8 +1988,6 @@ error:
                trace_ust_destroy_channel(uchan);
        }
 end:
-       free(app_ctx_provider_name);
-       free(app_ctx_name);
        return ret;
 }
 
@@ -2566,31 +2559,70 @@ error:
 /*
  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
  */
-ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
-               struct lttng_event_field **fields)
+enum lttng_error_code cmd_list_tracepoint_fields(enum lttng_domain_type domain,
+               struct lttng_payload *reply)
 {
+       enum lttng_error_code ret_code;
        int ret;
-       ssize_t nb_fields = 0;
+       unsigned int i, nb_fields;
+       struct lttng_event_field *fields = NULL;
+       struct lttcomm_list_command_header reply_command_header = {};
+       size_t reply_command_header_offset;
+
+       assert(reply);
+
+       /* Reserve space for command reply header. */
+       reply_command_header_offset = reply->buffer.size;
+       ret = lttng_dynamic_buffer_set_size(&reply->buffer,
+                       reply_command_header_offset +
+                               sizeof(struct lttcomm_list_command_header));
+       if (ret) {
+               ret_code = LTTNG_ERR_NOMEM;
+               goto error;
+       }
 
        switch (domain) {
        case LTTNG_DOMAIN_UST:
-               nb_fields = ust_app_list_event_fields(fields);
-               if (nb_fields < 0) {
-                       ret = LTTNG_ERR_UST_LIST_FAIL;
+               ret = ust_app_list_event_fields(&fields);
+               if (ret < 0) {
+                       ret_code = LTTNG_ERR_UST_LIST_FAIL;
                        goto error;
                }
+
                break;
        case LTTNG_DOMAIN_KERNEL:
        default:        /* fall-through */
-               ret = LTTNG_ERR_UND;
+               ret_code = LTTNG_ERR_UND;
+               goto error;
+       }
+
+       nb_fields = ret;
+
+       for (i = 0; i < nb_fields; i++) {
+               ret = lttng_event_field_serialize(&fields[i], reply);
+               if (ret) {
+                       ret_code = LTTNG_ERR_NOMEM;
+                       goto error;
+               }
+       }
+
+       if (nb_fields > UINT32_MAX) {
+               ERR("Tracepoint field count would overflow the tracepoint field listing command's reply");
+               ret_code = LTTNG_ERR_OVERFLOW;
                goto error;
        }
 
-       return nb_fields;
+       /* Update command reply header. */
+       reply_command_header.count = (uint32_t) nb_fields;
+
+       memcpy(reply->buffer.data + reply_command_header_offset, &reply_command_header,
+                       sizeof(reply_command_header));
+
+       ret_code = LTTNG_OK;
 
 error:
-       /* Return negative value to differentiate return code */
-       return -ret;
+       free(fields);
+       return ret_code;
 }
 
 enum lttng_error_code cmd_list_syscalls(