Relayd: disallow-clear option parsing

[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 7b313818e5c09a5719339740f47b2787304d461b..705b5d6c52247be9e1d318b7a8dd94ec39123129 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -70,10 +70,20 @@
 #include "stream.h"
 #include "connection.h"
 #include "tracefile-array.h"
+#include "tcp_keep_alive.h"
+
+static const char *help_msg =
+#ifdef LTTNG_EMBED_HELP
+#include <lttng-relayd.8.h>
+#else
+NULL
+#endif
+;
 
 /* command line options */
 char *opt_output_path;
 static int opt_daemon, opt_background;
+static int opt_allow_clear = 1;
 
 /*
  * We need to wait for listener and live listener threads, as well as
@@ -162,6 +172,7 @@ static struct option long_options[] = {
        { "verbose", 0, 0, 'v', },
        { "config", 1, 0, 'f' },
        { "version", 0, 0, 'V' },
+       { "disallow-clear", 0, 0, 'x' },
        { NULL, 0, 0, 0, },
 };
 
@@ -250,9 +261,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'h':
-               ret = utils_show_man_page(8, "lttng-relayd");
+               ret = utils_show_help(8, "lttng-relayd", help_msg);
                if (ret) {
-                       ERR("Cannot view man page lttng-relayd(8)");
+                       ERR("Cannot show --help for `lttng-relayd`");
                        perror("exec");
                }
                exit(EXIT_FAILURE);
@@ -283,6 +294,10 @@ static int set_option(int opt, const char *arg, const char *optname)
                        }
                }
                break;
+       case 'x':
+               /* Disallow clear */
+               opt_allow_clear = 0;
+               break;
        default:
                /* Unknown option or other error.
                 * Error is printed by getopt, just return */
@@ -358,6 +373,7 @@ static int set_options(int argc, char **argv)
        int orig_optopt = optopt, orig_optind = optind;
        char *default_address, *optstring;
        const char *config_path = NULL;
+       const char *value = NULL;
 
        optstring = utils_generate_optstring(long_options,
                        sizeof(long_options) / sizeof(struct option));
@@ -470,6 +486,20 @@ static int set_options(int argc, char **argv)
                }
        }
 
+       if (opt_allow_clear) {
+               /* Check if env variable exists. */
+               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);
        return retval;
@@ -740,6 +770,7 @@ static struct lttcomm_sock *relay_socket_create(struct lttng_uri *uri)
 
        ret = sock->ops->bind(sock);
        if (ret < 0) {
+               PERROR("Failed to bind socket");
                goto error;
        }
 
@@ -891,6 +922,15 @@ restart:
                                        lttcomm_destroy_sock(newsock);
                                        goto error;
                                }
+
+                               ret = socket_apply_keep_alive_config(newsock->fd);
+                               if (ret < 0) {
+                                       ERR("Failed to apply TCP keep-alive configuration on socket (%i)",
+                                                       newsock->fd);
+                                       lttcomm_destroy_sock(newsock);
+                                       goto error;
+                               }
+
                                new_conn = connection_create(newsock, type);
                                if (!new_conn) {
                                        lttcomm_destroy_sock(newsock);
@@ -969,12 +1009,16 @@ static void *relay_thread_dispatcher(void *data)
 
        health_code_update();
 
-       while (!CMM_LOAD_SHARED(dispatch_thread_exit)) {
+       for (;;) {
                health_code_update();
 
                /* Atomically prepare the queue futex */
                futex_nto1_prepare(&relay_conn_queue.futex);
 
+               if (CMM_LOAD_SHARED(dispatch_thread_exit)) {
+                       break;
+               }
+
                do {
                        health_code_update();
 
@@ -1579,6 +1623,7 @@ static int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
 {
        int ret;
        struct lttcomm_relayd_version reply, msg;
+       bool compatible = true;
 
        conn->version_check_done = 1;
 
@@ -1603,9 +1648,7 @@ static int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
        if (reply.major != be32toh(msg.major)) {
                DBG("Incompatible major versions (%u vs %u), deleting session",
                                reply.major, be32toh(msg.major));
-               connection_put(conn);
-               ret = 0;
-               goto end;
+               compatible = false;
        }
 
        conn->major = reply.major;
@@ -1624,6 +1667,11 @@ static int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
                ERR("Relay sending version");
        }
 
+       if (!compatible) {
+               ret = -1;
+               goto end;
+       }
+
        DBG("Version check done using protocol %u.%u", conn->major,
                        conn->minor);
 
@@ -2027,8 +2075,13 @@ static int relay_recv_index(struct lttcomm_relayd_hdr *recv_hdr,
                /* no flush. */
                ret = 0;
        } else {
+               /*
+                * ret < 0
+                *
+                * relay_index_try_flush is responsible for the self-reference
+                * put of the index object on error.
+                */
                ERR("relay_index_try_flush error %d", ret);
-               relay_index_put(index);
                ret = -1;
        }
 
@@ -2228,9 +2281,13 @@ static int handle_index_data(struct relay_stream *stream, uint64_t net_seq_num,
                /* No flush. */
                ret = 0;
        } else {
-               /* Put self-ref for this index due to error. */
-               relay_index_put(index);
-               index = NULL;
+               /*
+                * ret < 0
+                *
+                * relay_index_try_flush is responsible for the self-reference
+                * put of the index object on error.
+                */
+               ERR("relay_index_try_flush error %d", ret);
                ret = -1;
        }
 end:
@@ -2748,6 +2805,10 @@ int main(int argc, char **argv)
                goto exit_options;
        }
 
+       if (!opt_allow_clear) {
+               DBG("Clear command disallowed.");
+       }
+
        /* Try to create directory if -o, --output is specified. */
        if (opt_output_path) {
                if (*opt_output_path != '/') {
@@ -2937,6 +2998,12 @@ exit_init_data:
        health_app_destroy(health_relayd);
 exit_health_app_create:
 exit_options:
+       /*
+        * Wait for all pending call_rcu work to complete before tearing
+        * down data structures. call_rcu worker may be trying to
+        * perform lookups in those structures.
+        */
+       rcu_barrier();
        relayd_cleanup();
 
        /* Ensure all prior call_rcu are done. */