relayd: Implement get_configuration relayd protocol command

[lttng-tools.git] / src / bin / lttng-relayd / main.c

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index 54f31d7218a175fa16cbc8a7827f53c393a7f616..d874a9c50bdcabfbbc5bf0bc49c584e1eb635665 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -98,7 +98,7 @@ enum relay_connection_status {
 
 /* command line options */
 char *opt_output_path, *opt_working_directory;
-static int opt_daemon, opt_background, opt_print_version;
+static int opt_daemon, opt_background, opt_print_version, opt_allow_clear = 1;
 enum relay_group_output_by opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_UNKNOWN;
 
 /*
@@ -189,6 +189,7 @@ static struct option long_options[] = {
        { "working-directory", 1, 0, 'w', },
        { "group-output-by-session", 0, 0, 's', },
        { "group-output-by-host", 0, 0, 'p', },
+       { "disallow-clear", 0, 0, 'x' },
        { NULL, 0, 0, 0, },
 };
 
@@ -355,6 +356,10 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_HOST;
                break;
+       case 'x':
+               /* Disallow clear */
+               opt_allow_clear = 0;
+               break;
        default:
                /* Unknown option or other error.
                 * Error is printed by getopt, just return */
@@ -562,6 +567,19 @@ static int set_options(int argc, char **argv)
        if (opt_group_output_by == RELAYD_GROUP_OUTPUT_BY_UNKNOWN) {
                opt_group_output_by = RELAYD_GROUP_OUTPUT_BY_HOST;
        }
+       if (opt_allow_clear) {
+               /* Check if env variable exists. */
+               const char *value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_DISALLOW_CLEAR_ENV);
+               if (value) {
+                       ret = config_parse_value(value);
+                       if (ret < 0) {
+                               ERR("Invalid value for %s specified", DEFAULT_LTTNG_RELAYD_DISALLOW_CLEAR_ENV);
+                               retval = -1;
+                               goto exit;
+                       }
+                       opt_allow_clear = !ret;
+               }
+       }
 
 exit:
        free(optstring);
@@ -2848,6 +2866,57 @@ end_no_reply:
        return ret;
 }
 
+/*
+ * relay_get_configuration: query whether feature is available
+ */
+static int relay_get_configuration(const struct lttcomm_relayd_hdr *recv_hdr,
+               struct relay_connection *conn,
+               const struct lttng_buffer_view *payload)
+{
+       int ret = 0;
+       ssize_t send_ret;
+       struct lttcomm_relayd_get_configuration *msg;
+       struct lttcomm_relayd_get_configuration_reply reply = {};
+       struct lttng_buffer_view header_view;
+       uint64_t query_flags = 0;
+       uint64_t result_flags = 0;
+
+       header_view = lttng_buffer_view_from_view(payload, 0, sizeof(*msg));
+       if (!header_view.data) {
+               ERR("Failed to receive payload of chunk close command");
+               ret = -1;
+               goto end_no_reply;
+       }
+
+       /* Convert to host endianness. */
+       msg = (typeof(msg)) header_view.data;
+       query_flags = be64toh(msg->query_flags);
+
+       if (query_flags) {
+               ret = LTTNG_ERR_INVALID_PROTOCOL;
+               goto reply;
+       }
+       if (opt_allow_clear) {
+               result_flags |= LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED;
+       }
+       ret = 0;
+reply:
+       reply = (typeof(reply)){
+               .generic.ret_code = htobe32((uint32_t)
+                       (ret == 0 ? LTTNG_OK : LTTNG_ERR_INVALID_PROTOCOL)),
+               .relayd_configuration_flags = htobe64(result_flags),
+       };
+       send_ret = conn->sock->ops->sendmsg(
+                       conn->sock, &reply, sizeof(reply), 0);
+       if (send_ret < (ssize_t) sizeof(reply)) {
+               ERR("Failed to send \"get configuration\" command reply (ret = %zd)",
+                               send_ret);
+               ret = -1;
+       }
+end_no_reply:
+       return ret;
+}
+
 #define DBG_CMD(cmd_name, conn) \
                DBG3("Processing \"%s\" command for socket %i", cmd_name, conn->sock->fd);
 
@@ -2926,6 +2995,10 @@ static int relay_process_control_command(struct relay_connection *conn,
                DBG_CMD("RELAYD_TRACE_CHUNK_EXISTS", conn);
                ret = relay_trace_chunk_exists(header, conn, payload);
                break;
+       case RELAYD_GET_CONFIGURATION:
+               DBG_CMD("RELAYD_GET_CONFIGURATION", conn);
+               ret = relay_get_configuration(header, conn, payload);
+               break;
        case RELAYD_UPDATE_SYNC_INFO:
        default:
                ERR("Received unknown command (%u)", header->cmd);
@@ -3811,6 +3884,8 @@ int main(int argc, char **argv)
                goto exit_options;
        }
 
+       DBG("Clear command %s", opt_allow_clear ? "allowed" : "disallowed");
+
        /* Try to create directory if -o, --output is specified. */
        if (opt_output_path) {
                if (*opt_output_path != '/') {