Initialize command header to zero
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
index 5d098d7689a10e8b80417e92ea2da7efd85f5eb2..dbd99cc637659e242c1012cd6717f20b4e0a36d4 100644 (file)
@@ -17,7 +17,6 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <getopt.h>
 #include <grp.h>
@@ -38,7 +37,6 @@
 #include <sys/wait.h>
 #include <urcu/uatomic.h>
 #include <unistd.h>
-#include <config.h>
 
 #include <common/common.h>
 #include <common/compat/socket.h>
@@ -49,7 +47,7 @@
 #include <common/relayd/relayd.h>
 #include <common/utils.h>
 #include <common/daemonize.h>
-#include <common/config/config.h>
+#include <common/config/session-config.h>
 
 #include "lttng-sessiond.h"
 #include "buffer-registry.h"
@@ -873,34 +871,57 @@ error:
  * right amount of memory and copying the original information from the lsm
  * structure.
  *
- * Return total size of the buffer pointed by buf.
+ * Return 0 on success, negative value on error.
  */
-static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
+static int setup_lttng_msg(struct command_ctx *cmd_ctx,
+       const void *payload_buf, size_t payload_len,
+       const void *cmd_header_buf, size_t cmd_header_len)
 {
-       int ret, buf_size;
+       int ret = 0;
+       const size_t header_len = sizeof(struct lttcomm_lttng_msg);
+       const size_t cmd_header_offset = header_len;
+       const size_t payload_offset = cmd_header_offset + cmd_header_len;
+       const size_t total_msg_size = header_len + cmd_header_len + payload_len;
 
-       buf_size = size;
+       cmd_ctx->llm = zmalloc(total_msg_size);
 
-       cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
        if (cmd_ctx->llm == NULL) {
                PERROR("zmalloc");
                ret = -ENOMEM;
-               goto error;
+               goto end;
        }
 
        /* Copy common data */
        cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
        cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
+       cmd_ctx->llm->cmd_header_size = cmd_header_len;
+       cmd_ctx->llm->data_size = payload_len;
+       cmd_ctx->lttng_msg_size = total_msg_size;
 
-       cmd_ctx->llm->data_size = size;
-       cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
+       /* Copy command header */
+       if (cmd_header_len) {
+               memcpy(((uint8_t *) cmd_ctx->llm) + cmd_header_offset, cmd_header_buf,
+                       cmd_header_len);
+       }
 
-       return buf_size;
+       /* Copy payload */
+       if (payload_len) {
+               memcpy(((uint8_t *) cmd_ctx->llm) + payload_offset, payload_buf,
+                       payload_len);
+       }
 
-error:
+end:
        return ret;
 }
 
+/*
+ * Version of setup_lttng_msg() without command header.
+ */
+static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
+       void *payload_buf, size_t payload_len)
+{
+       return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
+}
 /*
  * Update the kernel poll set of all channel fd available over all tracing
  * session. Add the wakeup pipe at the end of the set.
@@ -3062,7 +3083,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
                break;
        default:
                /* Setup lttng message with no payload */
-               ret = setup_lttng_msg(cmd_ctx, 0);
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0);
                if (ret < 0) {
                        /* This label does not try to unlock the session */
                        goto init_setup_error;
@@ -3345,9 +3366,74 @@ skip_domain:
        switch (cmd_ctx->lsm->cmd_type) {
        case LTTNG_ADD_CONTEXT:
        {
-               ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
+               /*
+                * 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 = 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 = 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;
+                       }
+               }
+
+               /*
+                * cmd_add_context assumes ownership of the provider and context
+                * names.
+                */
+               ret = cmd_add_context(cmd_ctx->session,
+                               cmd_ctx->lsm->domain.type,
                                cmd_ctx->lsm->u.context.channel_name,
-                               &cmd_ctx->lsm->u.context.ctx, kernel_poll_pipe[1]);
+                               &cmd_ctx->lsm->u.context.ctx,
+                               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) {
+                       goto error;
+               }
                break;
        }
        case LTTNG_DISABLE_CHANNEL:
@@ -3539,18 +3625,14 @@ skip_domain:
                 * Setup lttng message with payload size set to the event list size in
                 * bytes and then copy list into the llm payload.
                 */
-               ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
+                       sizeof(struct lttng_event) * nb_events);
+               free(events);
+
                if (ret < 0) {
-                       free(events);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, events,
-                               sizeof(struct lttng_event) * nb_events);
-
-               free(events);
-
                ret = LTTNG_OK;
                break;
        }
@@ -3573,19 +3655,14 @@ skip_domain:
                 * Setup lttng message with payload size set to the event list size in
                 * bytes and then copy list into the llm payload.
                 */
-               ret = setup_lttng_msg(cmd_ctx,
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
                                sizeof(struct lttng_event_field) * nb_fields);
+               free(fields);
+
                if (ret < 0) {
-                       free(fields);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, fields,
-                               sizeof(struct lttng_event_field) * nb_fields);
-
-               free(fields);
-
                ret = LTTNG_OK;
                break;
        }
@@ -3605,18 +3682,14 @@ skip_domain:
                 * Setup lttng message with payload size set to the event list size in
                 * bytes and then copy list into the llm payload.
                 */
-               ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
+                       sizeof(struct lttng_event) * nb_events);
+               free(events);
+
                if (ret < 0) {
-                       free(events);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, events,
-                               sizeof(struct lttng_event) * nb_events);
-
-               free(events);
-
                ret = LTTNG_OK;
                break;
        }
@@ -3637,18 +3710,14 @@ skip_domain:
                 * Setup lttng message with payload size set to the event list size in
                 * bytes and then copy list into the llm payload.
                 */
-               ret = setup_lttng_msg(cmd_ctx, sizeof(int32_t) * nr_pids);
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, pids,
+                       sizeof(int32_t) * nr_pids);
+               free(pids);
+
                if (ret < 0) {
-                       free(pids);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, pids,
-                               sizeof(int) * nr_pids);
-
-               free(pids);
-
                ret = LTTNG_OK;
                break;
        }
@@ -3762,46 +3831,38 @@ skip_domain:
                        goto error;
                }
 
-               ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, domains,
+                       nb_dom * sizeof(struct lttng_domain));
+               free(domains);
+
                if (ret < 0) {
-                       free(domains);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, domains,
-                               nb_dom * sizeof(struct lttng_domain));
-
-               free(domains);
-
                ret = LTTNG_OK;
                break;
        }
        case LTTNG_LIST_CHANNELS:
        {
-               int nb_chan;
+               ssize_t payload_size;
                struct lttng_channel *channels = NULL;
 
-               nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
+               payload_size = cmd_list_channels(cmd_ctx->lsm->domain.type,
                                cmd_ctx->session, &channels);
-               if (nb_chan < 0) {
+               if (payload_size < 0) {
                        /* Return value is a negative lttng_error_code. */
-                       ret = -nb_chan;
+                       ret = -payload_size;
                        goto error;
                }
 
-               ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, channels,
+                       payload_size);
+               free(channels);
+
                if (ret < 0) {
-                       free(channels);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, channels,
-                               nb_chan * sizeof(struct lttng_channel));
-
-               free(channels);
-
                ret = LTTNG_OK;
                break;
        }
@@ -3809,52 +3870,65 @@ skip_domain:
        {
                ssize_t nb_event;
                struct lttng_event *events = NULL;
+               struct lttcomm_event_command_header cmd_header;
+               size_t total_size;
+
+               memset(&cmd_header, 0, sizeof(cmd_header));
+               /* Extended infos are included at the end of events */
+               nb_event = cmd_list_events(cmd_ctx->lsm->domain.type,
+                       cmd_ctx->session, cmd_ctx->lsm->u.list.channel_name,
+                       &events, &total_size);
 
-               nb_event = cmd_list_events(cmd_ctx->lsm->domain.type, cmd_ctx->session,
-                               cmd_ctx->lsm->u.list.channel_name, &events);
                if (nb_event < 0) {
                        /* Return value is a negative lttng_error_code. */
                        ret = -nb_event;
                        goto error;
                }
 
-               ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
+               cmd_header.nb_events = nb_event;
+               ret = setup_lttng_msg(cmd_ctx, events, total_size,
+                       &cmd_header, sizeof(cmd_header));
+               free(events);
+
                if (ret < 0) {
-                       free(events);
                        goto setup_error;
                }
 
-               /* Copy event list into message payload */
-               memcpy(cmd_ctx->llm->payload, events,
-                               nb_event * sizeof(struct lttng_event));
-
-               free(events);
-
                ret = LTTNG_OK;
                break;
        }
        case LTTNG_LIST_SESSIONS:
        {
                unsigned int nr_sessions;
+               void *sessions_payload;
+               size_t payload_len;
 
                session_lock_list();
                nr_sessions = lttng_sessions_count(
                                LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
                                LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
+               payload_len = sizeof(struct lttng_session) * nr_sessions;
+               sessions_payload = zmalloc(payload_len);
 
-               ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * nr_sessions);
-               if (ret < 0) {
+               if (!sessions_payload) {
                        session_unlock_list();
+                       ret = -ENOMEM;
                        goto setup_error;
                }
 
-               /* Filled the session array */
-               cmd_list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload),
+               cmd_list_lttng_sessions(sessions_payload,
                        LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
                        LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
-
                session_unlock_list();
 
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload,
+                       payload_len);
+               free(sessions_payload);
+
+               if (ret < 0) {
+                       goto setup_error;
+               }
+
                ret = LTTNG_OK;
                break;
        }
@@ -3884,14 +3958,10 @@ skip_domain:
        case LTTNG_DATA_PENDING:
        {
                int pending_ret;
-
-               /* 1 byte to return whether or not data is pending */
-               ret = setup_lttng_msg(cmd_ctx, 1);
-               if (ret < 0) {
-                       goto setup_error;
-               }
+               uint8_t pending_ret_byte;
 
                pending_ret = cmd_data_pending(cmd_ctx->session);
+
                /*
                 * FIXME
                 *
@@ -3902,7 +3972,10 @@ skip_domain:
                 * "unknown" error.
                 */
                if (pending_ret == 0 || pending_ret == 1) {
-                       ret = LTTNG_OK;
+                       /*
+                        * ret will be set to LTTNG_OK at the end of
+                        * this function.
+                        */
                } else if (pending_ret < 0) {
                        ret = LTTNG_ERR_UNK;
                        goto setup_error;
@@ -3911,7 +3984,17 @@ skip_domain:
                        goto setup_error;
                }
 
-               *cmd_ctx->llm->payload = (uint8_t) pending_ret;
+               pending_ret_byte = (uint8_t) pending_ret;
+
+               /* 1 byte to return whether or not data is pending */
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
+                       &pending_ret_byte, 1);
+
+               if (ret < 0) {
+                       goto setup_error;
+               }
+
+               ret = LTTNG_OK;
                break;
        }
        case LTTNG_SNAPSHOT_ADD_OUTPUT:
@@ -3924,13 +4007,13 @@ skip_domain:
                        goto error;
                }
 
-               ret = setup_lttng_msg(cmd_ctx, sizeof(reply));
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply,
+                       sizeof(reply));
                if (ret < 0) {
                        goto setup_error;
                }
 
                /* Copy output list into message payload */
-               memcpy(cmd_ctx->llm->payload, &reply, sizeof(reply));
                ret = LTTNG_OK;
                break;
        }
@@ -3951,20 +4034,15 @@ skip_domain:
                        goto error;
                }
 
-               ret = setup_lttng_msg(cmd_ctx,
+               assert((nb_output > 0 && outputs) || nb_output == 0);
+               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, outputs,
                                nb_output * sizeof(struct lttng_snapshot_output));
+               free(outputs);
+
                if (ret < 0) {
-                       free(outputs);
                        goto setup_error;
                }
 
-               if (outputs) {
-                       /* Copy output list into message payload */
-                       memcpy(cmd_ctx->llm->payload, outputs,
-                                       nb_output * sizeof(struct lttng_snapshot_output));
-                       free(outputs);
-               }
-
                ret = LTTNG_OK;
                break;
        }
@@ -4073,7 +4151,7 @@ skip_domain:
 error:
        if (cmd_ctx->llm == NULL) {
                DBG("Missing llm structure. Allocating one.");
-               if (setup_lttng_msg(cmd_ctx, 0) < 0) {
+               if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
                        goto setup_error;
                }
        }
@@ -4903,7 +4981,7 @@ end:
 
 /*
  * config_entry_handler_cb used to handle options read from a config file.
- * See config_entry_handler_cb comment in common/config/config.h for the
+ * See config_entry_handler_cb comment in common/config/session-config.h for the
  * return value conventions.
  */
 static int config_entry_handler(const struct config_entry *entry, void *unused)
@@ -6136,11 +6214,12 @@ exit_health_sessiond_cleanup:
 exit_create_run_as_worker_cleanup:
 
 exit_options:
+       /* Ensure all prior call_rcu are done. */
+       rcu_barrier();
+
        sessiond_cleanup_options();
 
 exit_set_signal_handler:
-       /* Ensure all prior call_rcu are done. */
-       rcu_barrier();
 
        if (!retval) {
                exit(EXIT_SUCCESS);
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