relayd: Don't bypass the fd tracker when closing file descriptors
[deliverable/lttng-tools.git] / src / bin / lttng-relayd / main.c
index 09a73e392ada24798e5e1c143000f0572a253c2f..ab7d914563cd0a8e7a3b016ecb2f7e278ec9ebfc 100644 (file)
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <sys/resource.h>
 #include <inttypes.h>
 #include <urcu/futex.h>
 #include <urcu/uatomic.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <ctype.h>
 
 #include <lttng/lttng.h>
 #include <common/common.h>
@@ -155,6 +157,9 @@ static uint64_t last_relay_stream_id;
  */
 static struct relay_conn_queue relay_conn_queue;
 
+/* Cap of file desriptors to be in simultaneous use by the relay daemon. */
+static unsigned int lttng_opt_fd_cap;
+
 /* Global relay stream hash table. */
 struct lttng_ht *relay_streams_ht;
 
@@ -167,6 +172,9 @@ struct lttng_ht *sessions_ht;
 /* Relayd health monitoring */
 struct health_app *health_relayd;
 
+/* Global fd tracker. */
+struct fd_tracker *the_fd_tracker;
+
 static struct option long_options[] = {
        { "control-port", 1, 0, 'C', },
        { "data-port", 1, 0, 'D', },
@@ -174,6 +182,7 @@ static struct option long_options[] = {
        { "daemonize", 0, 0, 'd', },
        { "background", 0, 0, 'b', },
        { "group", 1, 0, 'g', },
+       { "fd-cap", 1, 0, '\0', },
        { "help", 0, 0, 'h', },
        { "output", 1, 0, 'o', },
        { "verbose", 0, 0, 'v', },
@@ -196,9 +205,33 @@ static int set_option(int opt, const char *arg, const char *optname)
 
        switch (opt) {
        case 0:
-               fprintf(stderr, "option %s", optname);
-               if (arg) {
-                       fprintf(stderr, " with arg %s\n", arg);
+               if (!strcmp(optname, "fd-cap")) {
+                       unsigned long v;
+
+                       errno = 0;
+                       v = strtoul(arg, NULL, 0);
+                       if (errno != 0 || !isdigit(arg[0])) {
+                               ERR("Wrong value in --fd-cap parameter: %s", arg);
+                               ret = -1;
+                               goto end;
+                       }
+                       if (v < DEFAULT_RELAYD_MINIMAL_FD_CAP) {
+                               ERR("File descriptor cap must be set to at least %d",
+                                               DEFAULT_RELAYD_MINIMAL_FD_CAP);
+                       }
+                       if (v >= UINT_MAX) {
+                               ERR("File descriptor cap overflow in --fd-cap parameter: %s", arg);
+                               ret = -1;
+                               goto end;
+                       }
+                       lttng_opt_fd_cap = (unsigned int) v;
+                       DBG3("File descriptor cap set to %u", lttng_opt_fd_cap);
+
+               } else {
+                       fprintf(stderr, "unknown option %s", optname);
+                       if (arg) {
+                               fprintf(stderr, " with arg %s\n", arg);
+                       }
                }
                break;
        case 'C':
@@ -486,6 +519,18 @@ static int set_options(int argc, char **argv)
                        goto exit;
                }
        }
+       if (lttng_opt_fd_cap == 0) {
+               int ret;
+               struct rlimit rlimit;
+
+               ret = getrlimit(RLIMIT_NOFILE, &rlimit);
+               if (ret) {
+                       PERROR("Failed to get file descriptor limit");
+                       retval = -1;
+               }
+
+               lttng_opt_fd_cap = rlimit.rlim_cur;
+       }
 
 exit:
        free(optstring);
@@ -494,13 +539,9 @@ exit:
 
 static void print_global_objects(void)
 {
-       rcu_register_thread();
-
        print_viewer_streams();
        print_relay_streams();
        print_sessions();
-
-       rcu_unregister_thread();
 }
 
 /*
@@ -532,6 +573,7 @@ static void relayd_cleanup(void)
        if (tracing_group_name_override) {
                free((void *) tracing_group_name);
        }
+       fd_tracker_log(the_fd_tracker);
 }
 
 /*
@@ -1106,16 +1148,19 @@ static int relay_create_session(const struct lttcomm_relayd_hdr *recv_hdr,
 
        memset(&reply, 0, sizeof(reply));
 
-       switch (conn->minor) {
-       case 1:
-       case 2:
-       case 3:
-               break;
-       case 4: /* LTTng sessiond 2.4 */
-       default:
+       if (conn->minor < 4) {
+               /* From 2.1 to 2.3 */
+               ret = 0;
+       } else if (conn->minor >= 4 && conn->minor < 11) {
+               /* From 2.4 to 2.10 */
                ret = cmd_create_session_2_4(payload, session_name,
                        hostname, &live_timer, &snapshot);
+       } else {
+               /* From 2.11 to ... */
+               ret = cmd_create_session_2_11(payload, session_name,
+                       hostname, &live_timer, &snapshot);
        }
+
        if (ret < 0) {
                goto send_reply;
        }
@@ -1195,6 +1240,7 @@ static int relay_add_stream(const struct lttcomm_relayd_hdr *recv_hdr,
        uint64_t stream_handle = -1ULL;
        char *path_name = NULL, *channel_name = NULL;
        uint64_t tracefile_size = 0, tracefile_count = 0;
+       struct relay_stream_chunk_id stream_chunk_id = { 0 };
 
        if (!session || !conn->version_check_done) {
                ERR("Trying to add a stream before version check");
@@ -1202,17 +1248,22 @@ static int relay_add_stream(const struct lttcomm_relayd_hdr *recv_hdr,
                goto end_no_session;
        }
 
-       switch (session->minor) {
-       case 1: /* LTTng sessiond 2.1. Allocates path_name and channel_name. */
+       if (session->minor == 1) {
+               /* For 2.1 */
                ret = cmd_recv_stream_2_1(payload, &path_name,
                        &channel_name);
-               break;
-       case 2: /* LTTng sessiond 2.2. Allocates path_name and channel_name. */
-       default:
+       } else if (session->minor > 1 && session->minor < 11) {
+               /* From 2.2 to 2.10 */
                ret = cmd_recv_stream_2_2(payload, &path_name,
                        &channel_name, &tracefile_size, &tracefile_count);
-               break;
+       } else {
+               /* From 2.11 to ... */
+               ret = cmd_recv_stream_2_11(payload, &path_name,
+                       &channel_name, &tracefile_size, &tracefile_count,
+                       &stream_chunk_id.value);
+               stream_chunk_id.is_set = true;
        }
+
        if (ret < 0) {
                goto send_reply;
        }
@@ -1229,7 +1280,8 @@ static int relay_add_stream(const struct lttcomm_relayd_hdr *recv_hdr,
 
        /* We pass ownership of path_name and channel_name. */
        stream = stream_create(trace, stream_handle, path_name,
-                       channel_name, tracefile_size, tracefile_count);
+               channel_name, tracefile_size, tracefile_count,
+               &stream_chunk_id);
        path_name = NULL;
        channel_name = NULL;
 
@@ -2475,7 +2527,8 @@ static int relay_rotate_session_stream(const struct lttcomm_relayd_hdr *recv_hdr
                goto end_stream_unlock;
        }
 
-       stream->chunk_id = stream_info.new_chunk_id;
+       assert(stream->current_chunk_id.is_set);
+       stream->current_chunk_id.value = stream_info.new_chunk_id;
 
        if (stream->is_metadata) {
                /*
@@ -2809,7 +2862,8 @@ int relay_rotate_pending(const struct lttcomm_relayd_hdr *recv_hdr,
 
        chunk_id = be64toh(msg.chunk_id);
 
-       DBG("Evaluating rotate pending for chunk id %" PRIu64, chunk_id);
+       DBG("Evaluating rotate pending for session \"%s\" and  chunk id %" PRIu64,
+                       session->session_name, chunk_id);
 
        /*
         * Iterate over all the streams in the session and check if they are
@@ -2831,7 +2885,7 @@ int relay_rotate_pending(const struct lttcomm_relayd_hdr *recv_hdr,
                        rotate_pending = true;
                        DBG("Stream %" PRIu64 " is still rotating",
                                        stream->stream_handle);
-               } else if (stream->chunk_id < chunk_id) {
+               } else if (stream->current_chunk_id.value < chunk_id) {
                        /*
                         * Stream closed on the consumer but still active on the
                         * relay.
@@ -3256,7 +3310,6 @@ static enum relay_connection_status relay_process_data_receive_header(
                DBG3("Partial reception of data connection header (received %" PRIu64 " bytes, %" PRIu64 " bytes left to receive, fd = %i)",
                                state->received, state->left_to_receive,
                                conn->sock->fd);
-               ret = 0;
                goto end;
        }
 
@@ -3323,7 +3376,6 @@ static enum relay_connection_status relay_process_data_receive_header(
                conn->protocol.data.state.receive_payload.rotate_index = true;
        }
 
-       ret = 0;
 end_stream_unlock:
        pthread_mutex_unlock(&stream->lock);
        stream_put(stream);
@@ -3346,10 +3398,14 @@ static enum relay_connection_status relay_process_data_receive_payload(
        uint64_t left_to_receive = state->left_to_receive;
        struct relay_session *session;
 
+       DBG3("Receiving data for stream id %" PRIu64 " seqnum %" PRIu64 ", %" PRIu64" bytes received, %" PRIu64 " bytes left to receive",
+                       state->header.stream_id, state->header.net_seq_num,
+                       state->received, left_to_receive);
+
        stream = stream_get_by_id(state->header.stream_id);
        if (!stream) {
                /* Protocol error. */
-               DBG("relay_process_data_receive_payload: Cannot find stream %" PRIu64,
+               ERR("relay_process_data_receive_payload: cannot find stream %" PRIu64,
                                state->header.stream_id);
                status = RELAY_CONNECTION_STATUS_ERROR;
                goto end;
@@ -3357,10 +3413,13 @@ static enum relay_connection_status relay_process_data_receive_payload(
 
        pthread_mutex_lock(&stream->lock);
        session = stream->trace->session;
-
-       DBG3("Receiving data for stream id %" PRIu64 " seqnum %" PRIu64 ", %" PRIu64" bytes received, %" PRIu64 " bytes left to receive",
-                       state->header.stream_id, state->header.net_seq_num,
-                       state->received, left_to_receive);
+       if (!conn->session) {
+               ret = connection_set_session(conn, session);
+               if (ret) {
+                       status = RELAY_CONNECTION_STATUS_ERROR;
+                       goto end_stream_unlock;
+               }
+       }
 
        /*
         * The size of the "chunk" received on any iteration is bounded by:
@@ -3426,7 +3485,7 @@ static enum relay_connection_status relay_process_data_receive_payload(
 
        ret = write_padding_to_file(stream->stream_fd->fd,
                        state->header.padding_size);
-       if (ret < 0) {
+       if ((int64_t) ret < (int64_t) state->header.padding_size) {
                ERR("write_padding_to_file: fail stream %" PRIu64 " net_seq_num %" PRIu64 " ret %d",
                                stream->stream_handle,
                                state->header.net_seq_num, ret);
@@ -3688,6 +3747,26 @@ restart:
 
                                        status = relay_process_control(ctrl_conn);
                                        if (status != RELAY_CONNECTION_STATUS_OK) {
+                                               /*
+                                                * On socket error flag the session as aborted to force
+                                                * the cleanup of its stream otherwise it can leak
+                                                * during the lifetime of the relayd.
+                                                *
+                                                * This prevents situations in which streams can be
+                                                * left opened because an index was received, the
+                                                * control connection is closed, and the data
+                                                * connection is closed (uncleanly) before the packet's
+                                                * data provided.
+                                                *
+                                                * Since the control connection encountered an error,
+                                                * it is okay to be conservative and close the
+                                                * session right now as we can't rely on the protocol
+                                                * being respected anymore.
+                                                */
+                                               if (status == RELAY_CONNECTION_STATUS_ERROR) {
+                                                       session_abort(ctrl_conn->session);
+                                               }
+
                                                /* Clear the connection on error or close. */
                                                relay_thread_close_connection(&events,
                                                                pollfd,
@@ -3767,6 +3846,25 @@ restart:
                                status = relay_process_data(data_conn);
                                /* Connection closed or error. */
                                if (status != RELAY_CONNECTION_STATUS_OK) {
+                                       /*
+                                        * On socket error flag the session as aborted to force
+                                        * the cleanup of its stream otherwise it can leak
+                                        * during the lifetime of the relayd.
+                                        *
+                                        * This prevents situations in which streams can be
+                                        * left opened because an index was received, the
+                                        * control connection is closed, and the data
+                                        * connection is closed (uncleanly) before the packet's
+                                        * data provided.
+                                        *
+                                        * Since the data connection encountered an error,
+                                        * it is okay to be conservative and close the
+                                        * session right now as we can't rely on the protocol
+                                        * being respected anymore.
+                                        */
+                                       if (status == RELAY_CONNECTION_STATUS_ERROR) {
+                                               session_abort(data_conn->session);
+                                       }
                                        relay_thread_close_connection(&events, pollfd,
                                                        data_conn);
                                        /*
@@ -3798,16 +3896,14 @@ restart:
 
 exit:
 error:
-       /* Cleanup reamaining connection object. */
+       /* Cleanup remaining connection object. */
        rcu_read_lock();
        cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter,
                        destroy_conn,
                        sock_n.node) {
                health_code_update();
 
-               if (session_abort(destroy_conn->session)) {
-                       assert(0);
-               }
+               session_abort(destroy_conn->session);
 
                /*
                 * No need to grab another ref, because we own
@@ -3872,6 +3968,11 @@ int main(int argc, char **argv)
                goto exit_options;
        }
 
+       ret = fclose(stdin);
+       if (ret) {
+               PERROR("Failed to close stdin");
+               goto exit_options;
+       }
        /* Try to create directory if -o, --output is specified. */
        if (opt_output_path) {
                if (*opt_output_path != '/') {
@@ -3891,23 +3992,26 @@ int main(int argc, char **argv)
 
        /* Daemonize */
        if (opt_daemon || opt_background) {
-               int i;
-
                ret = lttng_daemonize(&child_ppid, &recv_child_signal,
                        !opt_background);
                if (ret < 0) {
                        retval = -1;
                        goto exit_options;
                }
+       }
 
-               /*
-                * We are in the child. Make sure all other file
-                * descriptors are closed, in case we are called with
-                * more opened file descriptors than the standard ones.
-                */
-               for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
-                       (void) close(i);
-               }
+       /*
+        * The RCU thread registration (and use, through the fd-tracker's
+        * creation) is done after the daemonization to allow us to not
+        * deal with liburcu's fork() management as the call RCU needs to
+        * be restored.
+        */
+       rcu_register_thread();
+
+       the_fd_tracker = fd_tracker_create(lttng_opt_fd_cap);
+       if (!the_fd_tracker) {
+               retval = -1;
+               goto exit_options;
        }
 
        /* Initialize thread health monitoring */
@@ -4072,6 +4176,9 @@ exit_options:
        /* Ensure all prior call_rcu are done. */
        rcu_barrier();
 
+       fd_tracker_destroy(the_fd_tracker);
+       rcu_unregister_thread();
+
        if (!retval) {
                exit(EXIT_SUCCESS);
        } else {
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