Basic serialization/deserialization for lttng_session

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

diff --git a/src/lib/lttng-ctl/lttng-ctl.cpp b/src/lib/lttng-ctl/lttng-ctl.cpp
index c5d47ebdc53d66b2182a6656b2ecb955fdf91942..9dff22a2bca57e1b7c22cc612ef96d36aa40bb63 100644 (file)
--- a/src/lib/lttng-ctl/lttng-ctl.cpp
+++ b/src/lib/lttng-ctl/lttng-ctl.cpp
@@ -266,7 +266,7 @@ int lttng_check_tracing_group(void)
        }
 
        /* Alloc group list of the right size */
-       grp_list = (gid_t *) zmalloc(grp_list_size * sizeof(gid_t));
+       grp_list = calloc<gid_t>(grp_list_size);
        if (!grp_list) {
                PERROR("malloc");
                goto end;
@@ -500,7 +500,7 @@ static int recv_sessiond_optional_data(size_t len, void **user_buf,
        size_t *user_len)
 {
        int ret = 0;
-       void *buf = NULL;
+       char *buf = NULL;
 
        if (len) {
                if (!user_len) {
@@ -508,7 +508,7 @@ static int recv_sessiond_optional_data(size_t len, void **user_buf,
                        goto end;
                }
 
-               buf = zmalloc(len);
+               buf = zmalloc<char>(len);
                if (!buf) {
                        ret = -ENOMEM;
                        goto end;
@@ -729,7 +729,7 @@ struct lttng_handle *lttng_create_handle(const char *session_name,
        int ret;
        struct lttng_handle *handle = NULL;
 
-       handle = (lttng_handle *) zmalloc(sizeof(struct lttng_handle));
+       handle = zmalloc<lttng_handle>();
        if (handle == NULL) {
                PERROR("malloc handle");
                goto end;
@@ -1576,13 +1576,13 @@ int lttng_enable_channel(struct lttng_handle *handle,
        /* Populate the channel extended attribute if necessary. */
        if (!channel->attr.extended.ptr) {
                struct lttng_channel_extended *extended =
-                               (struct lttng_channel_extended *) zmalloc(
-                                               sizeof(*extended));
+                               zmalloc<lttng_channel_extended>();
 
                if (!extended) {
                        ret = -LTTNG_ERR_NOMEM;
                        goto end;
                }
+
                lttng_channel_set_default_extended_attr(
                                &handle->domain, extended);
                channel->attr.extended.ptr = extended;
@@ -1747,13 +1747,13 @@ int lttng_list_tracepoint_fields(struct lttng_handle *handle,
        unsigned int nb_event_fields = 0;
        struct lttng_payload reply;
 
+       lttng_payload_init(&reply);
+
        if (handle == NULL) {
                ret = -LTTNG_ERR_INVALID;
                goto end;
        }
 
-       lttng_payload_init(&reply);
-
        memset(&lsm, 0, sizeof(lsm));
        lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
        COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
@@ -1807,6 +1807,7 @@ int lttng_list_tracepoint_fields(struct lttng_handle *handle,
        ret = nb_event_fields;
 
 end:
+       lttng_payload_reset(&reply);
        return ret;
 }
 
@@ -2210,51 +2211,59 @@ int lttng_destroy_session_no_wait(const char *session_name)
 int lttng_list_sessions(struct lttng_session **out_sessions)
 {
        int ret;
-       struct lttcomm_session_msg lsm;
-       const size_t session_size = sizeof(struct lttng_session) +
-                       sizeof(struct lttng_session_extended);
-       size_t session_count, i;
-       struct lttng_session_extended *sessions_extended_begin;
-       struct lttng_session *sessions = NULL;
+       struct lttcomm_session_msg lsm = {};
+       struct lttng_payload reply;
+       struct lttng_payload_view lsm_view =
+                       lttng_payload_view_init_from_buffer((const char *) &lsm, 0, sizeof(lsm));
+       unsigned int nb_sessions = 0;
 
-       memset(&lsm, 0, sizeof(lsm));
+       lttng_payload_init(&reply);
+
+       /* Initialize command parameters. */
        lsm.cmd_type = LTTNG_LIST_SESSIONS;
-       /*
-        * Initialize out_sessions to NULL so it is initialized when
-        * lttng_list_sessions returns 0, thus allowing *out_sessions to
-        * be subsequently freed.
-        */
-       *out_sessions = NULL;
-       ret = lttng_ctl_ask_sessiond(&lsm, (void**) &sessions);
-       if (ret <= 0) {
-               goto end;
-       }
-       if (!sessions) {
-               ret = -LTTNG_ERR_FATAL;
+
+       /* Execute command against the session daemon. */
+       ret = lttng_ctl_ask_sessiond_payload(&lsm_view, &reply);
+       if (ret < 0) {
                goto end;
        }
 
-       if (ret % session_size) {
-               ret = -LTTNG_ERR_UNK;
-               free(sessions);
-               goto end;
+       {
+               const struct lttcomm_list_command_header *cmd_reply_header = NULL;
+               const lttng_payload_view cmd_reply_header_view = lttng_payload_view_from_payload(
+                               &reply, 0, sizeof(*cmd_reply_header));
+
+               if (!lttng_payload_view_is_valid(&cmd_reply_header_view)) {
+                       ret = -LTTNG_ERR_INVALID_PROTOCOL;
+                       goto end;
+               }
+
+               cmd_reply_header = (const struct lttcomm_list_command_header *)
+                                                  cmd_reply_header_view.buffer.data;
+               if (cmd_reply_header->count > INT_MAX) {
+                       ret = -LTTNG_ERR_OVERFLOW;
+                       goto end;
+               }
+
+               nb_sessions = (unsigned int) cmd_reply_header->count;
        }
-       session_count = (size_t) ret / session_size;
-       sessions_extended_begin = (struct lttng_session_extended *)
-                       (&sessions[session_count]);
 
-       /* Set extended session info pointers. */
-       for (i = 0; i < session_count; i++) {
-               struct lttng_session *session = &sessions[i];
-               struct lttng_session_extended *extended =
-                               &(sessions_extended_begin[i]);
+       {
+               enum lttng_error_code ret_code;
+               lttng_payload_view cmd_reply_payload = lttng_payload_view_from_payload(
+                               &reply, sizeof(struct lttcomm_list_command_header), -1);
 
-               session->extended.ptr = extended;
+               ret_code = lttng_sessions_create_and_flatten_from_payload(
+                               &cmd_reply_payload, nb_sessions, out_sessions);
+               if (ret_code != LTTNG_OK) {
+                       ret = -((int) ret_code);
+                       goto end;
+               }
        }
 
-       ret = (int) session_count;
-       *out_sessions = sessions;
+       ret = (int) nb_sessions;
 end:
+       lttng_payload_reset(&reply);
        return ret;
 }