Fix: liblttng-ctl comm: lttng_event_context is not packed

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

diff --git a/src/bin/lttng-sessiond/client.cpp b/src/bin/lttng-sessiond/client.cpp
index 189c8eb34f4e9968408bc0789d1f83cf4f0122db..abd26fcb96f755b9687cfa2cdb23342e387d2bff 100644 (file)
--- a/src/bin/lttng-sessiond/client.cpp
+++ b/src/bin/lttng-sessiond/client.cpp
@@ -830,6 +830,60 @@ end:
        return ret_code;
 }
 
+static enum lttng_error_code receive_lttng_event_context(
+               const struct command_ctx *cmd_ctx,
+               int sock,
+               int *sock_error,
+               struct lttng_event_context **out_event_context)
+{
+       int ret;
+       const size_t event_context_len =
+                       (size_t) cmd_ctx->lsm.u.context.length;
+       ssize_t sock_recv_len;
+       enum lttng_error_code ret_code;
+       struct lttng_payload event_context_payload;
+
+       lttng_payload_init(&event_context_payload);
+
+       ret = lttng_dynamic_buffer_set_size(&event_context_payload.buffer,
+                       event_context_len);
+       if (ret) {
+               ret_code = LTTNG_ERR_NOMEM;
+               goto end;
+       }
+
+       sock_recv_len = lttcomm_recv_unix_sock(
+                       sock, event_context_payload.buffer.data,
+                       event_context_len);
+       if (sock_recv_len < 0 || sock_recv_len != event_context_len) {
+               ERR("Failed to receive event context in command payload");
+               *sock_error = 1;
+               ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+               goto end;
+       }
+
+       /* Deserialize event. */
+       {
+               struct lttng_payload_view event_context_view =
+                               lttng_payload_view_from_payload(
+                                               &event_context_payload, 0, -1);
+
+               if (lttng_event_context_create_from_payload(
+                               &event_context_view, out_event_context) !=
+                               event_context_len) {
+                       ERR("Invalid event context received as part of command payload");
+                       ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+                       goto end;
+               }
+       }
+
+       ret_code = LTTNG_OK;
+
+end:
+       lttng_payload_reset(&event_context_payload);
+       return ret_code;
+}
+
 /*
  * Version of setup_lttng_msg() without command header.
  */
@@ -1299,77 +1353,18 @@ skip_domain:
        switch (cmd_ctx->lsm.cmd_type) {
        case LTTNG_ADD_CONTEXT:
        {
-               lttng_event_context ctx;
-
-               /*
-                * An LTTNG_ADD_CONTEXT command might have a supplementary
-                * payload if the context being added is an application context.
-                */
-               if (cmd_ctx->lsm.u.context.ctx.ctx ==
-                               LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
-                       char *provider_name = NULL, *context_name = NULL;
-                       size_t provider_name_len =
-                                       cmd_ctx->lsm.u.context.provider_name_len;
-                       size_t context_name_len =
-                                       cmd_ctx->lsm.u.context.context_name_len;
-
-                       if (provider_name_len == 0 || context_name_len == 0) {
-                               /*
-                                * Application provider and context names MUST
-                                * be provided.
-                                */
-                               ret = -LTTNG_ERR_INVALID;
-                               goto error;
-                       }
-
-                       provider_name = (char *) zmalloc(provider_name_len + 1);
-                       if (!provider_name) {
-                               ret = -LTTNG_ERR_NOMEM;
-                               goto error;
-                       }
-                       cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name =
-                                       provider_name;
-
-                       context_name = (char *) zmalloc(context_name_len + 1);
-                       if (!context_name) {
-                               ret = -LTTNG_ERR_NOMEM;
-                               goto error_add_context;
-                       }
-                       cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name =
-                                       context_name;
-
-                       ret = lttcomm_recv_unix_sock(*sock, provider_name,
-                                       provider_name_len);
-                       if (ret < 0) {
-                               goto error_add_context;
-                       }
-
-                       ret = lttcomm_recv_unix_sock(*sock, context_name,
-                                       context_name_len);
-                       if (ret < 0) {
-                               goto error_add_context;
-                       }
-               }
+               struct lttng_event_context *event_context;
+               const enum lttng_error_code ret_code =
+                       receive_lttng_event_context(
+                               cmd_ctx, *sock, sock_error, &event_context);
 
-               /*
-                * cmd_add_context assumes ownership of the provider and context
-                * names.
-                */
-               ctx = cmd_ctx->lsm.u.context.ctx;
-               ret = cmd_add_context(cmd_ctx->session,
-                               cmd_ctx->lsm.domain.type,
-                               cmd_ctx->lsm.u.context.channel_name,
-                               &ctx,
-                               the_kernel_poll_pipe[1]);
-
-               cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name = NULL;
-               cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name = NULL;
-error_add_context:
-               free(cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name);
-               free(cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name);
-               if (ret < 0) {
+               if (ret_code != LTTNG_OK) {
+                       ret = (int) ret_code;
                        goto error;
                }
+
+               ret = cmd_add_context(cmd_ctx, event_context, the_kernel_poll_pipe[1]);
+               lttng_event_context_destroy(event_context);
                break;
        }
        case LTTNG_DISABLE_CHANNEL: