+++ /dev/null
-/*
- * liblttngctl.c
- *
- * Linux Trace Toolkit Control Library
- *
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#define _GNU_SOURCE
-#include <grp.h>
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <lttng-sessiond-comm.h>
-#include <lttng-share.h>
-#include <lttng/lttng.h>
-#include <lttngerr.h>
-
-/* Socket to session daemon for communication */
-static int sessiond_socket;
-static char sessiond_sock_path[PATH_MAX];
-
-/* Variables */
-static char *tracing_group;
-static int connected;
-
-/*
- * Copy string from src to dst and enforce null terminated byte.
- */
-static void copy_string(char *dst, const char *src, size_t len)
-{
- if (src && dst) {
- strncpy(dst, src, len);
- /* Enforce the NULL terminated byte */
- dst[len - 1] = '\0';
- } else if (dst) {
- dst[0] = '\0';
- }
-}
-
-/*
- * Copy domain to lttcomm_session_msg domain.
- *
- * If domain is unknown, default domain will be the kernel.
- */
-static void copy_lttng_domain(struct lttng_domain *dst, struct lttng_domain *src)
-{
- if (src && dst) {
- switch (src->type) {
- case LTTNG_DOMAIN_KERNEL:
- case LTTNG_DOMAIN_UST:
- case LTTNG_DOMAIN_UST_EXEC_NAME:
- case LTTNG_DOMAIN_UST_PID:
- case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
- memcpy(dst, src, sizeof(struct lttng_domain));
- break;
- default:
- dst->type = LTTNG_DOMAIN_KERNEL;
- break;
- }
- }
-}
-
-/*
- * Send lttcomm_session_msg to the session daemon.
- *
- * On success, return 0
- * On error, return error code
- */
-static int send_session_msg(struct lttcomm_session_msg *lsm)
-{
- int ret;
-
- if (!connected) {
- ret = -ENOTCONN;
- goto end;
- }
-
- ret = lttcomm_send_creds_unix_sock(sessiond_socket, lsm,
- sizeof(struct lttcomm_session_msg));
-
-end:
- return ret;
-}
-
-/*
- * Receive data from the sessiond socket.
- *
- * On success, return 0
- * On error, return recv() error code
- */
-static int recv_data_sessiond(void *buf, size_t len)
-{
- int ret;
-
- if (!connected) {
- ret = -ENOTCONN;
- goto end;
- }
-
- ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
-
-end:
- return ret;
-}
-
-/*
- * Check if the specified group name exist.
- *
- * If yes return 1, else return -1.
- */
-static int check_tracing_group(const char *grp_name)
-{
- struct group *grp_tracing; /* no free(). See getgrnam(3) */
- gid_t *grp_list;
- int grp_list_size, grp_id, i;
- int ret = -1;
-
- /* Get GID of group 'tracing' */
- grp_tracing = getgrnam(grp_name);
- if (grp_tracing == NULL) {
- /* NULL means not found also. getgrnam(3) */
- if (errno != 0) {
- perror("getgrnam");
- }
- goto end;
- }
-
- /* Get number of supplementary group IDs */
- grp_list_size = getgroups(0, NULL);
- if (grp_list_size < 0) {
- perror("getgroups");
- goto end;
- }
-
- /* Alloc group list of the right size */
- grp_list = malloc(grp_list_size * sizeof(gid_t));
- if (!grp_list) {
- ret = -1;
- goto end;
- }
- grp_id = getgroups(grp_list_size, grp_list);
- if (grp_id < -1) {
- perror("getgroups");
- goto free_list;
- }
-
- for (i = 0; i < grp_list_size; i++) {
- if (grp_list[i] == grp_tracing->gr_gid) {
- ret = 1;
- break;
- }
- }
-
-free_list:
- free(grp_list);
-
-end:
- return ret;
-}
-
-/*
- * Try connect to session daemon with sock_path.
- *
- * Return 0 on success, else -1
- */
-static int try_connect_sessiond(const char *sock_path)
-{
- int ret;
-
- /* If socket exist, we check if the daemon listens for connect. */
- ret = access(sock_path, F_OK);
- if (ret < 0) {
- /* Not alive */
- return -1;
- }
-
- ret = lttcomm_connect_unix_sock(sock_path);
- if (ret < 0) {
- /* Not alive */
- return -1;
- }
-
- ret = lttcomm_close_unix_sock(ret);
- if (ret < 0) {
- perror("lttcomm_close_unix_sock");
- }
-
- return 0;
-}
-
-/*
- * Set sessiond socket path by putting it in the global sessiond_sock_path
- * variable.
- */
-static int set_session_daemon_path(void)
-{
- int ret;
- int in_tgroup = 0; /* In tracing group */
- uid_t uid;
-
- uid = getuid();
-
- if (uid != 0) {
- /* Are we in the tracing group ? */
- in_tgroup = check_tracing_group(tracing_group);
- }
-
- if (uid == 0) {
- /* Root */
- copy_string(sessiond_sock_path,
- DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
- sizeof(sessiond_sock_path));
- } else if (in_tgroup) {
- /* Tracing group */
- copy_string(sessiond_sock_path,
- DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
- sizeof(sessiond_sock_path));
-
- ret = try_connect_sessiond(sessiond_sock_path);
- if (ret < 0) {
- /* Global session daemon not available */
- if (snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
- DEFAULT_HOME_CLIENT_UNIX_SOCK,
- getenv("HOME")) < 0) {
- return -ENOMEM;
- }
- }
- } else {
- /* Not in tracing group and not root, default */
- if (snprintf(sessiond_sock_path, PATH_MAX,
- DEFAULT_HOME_CLIENT_UNIX_SOCK,
- getenv("HOME")) < 0) {
- return -ENOMEM;
- }
- }
-
- return 0;
-}
-
-/*
- * Connect to the LTTng session daemon.
- *
- * On success, return 0. On error, return -1.
- */
-static int connect_sessiond(void)
-{
- int ret;
-
- ret = set_session_daemon_path();
- if (ret < 0) {
- return ret;
- }
-
- /* Connect to the sesssion daemon */
- ret = lttcomm_connect_unix_sock(sessiond_sock_path);
- if (ret < 0) {
- return ret;
- }
-
- sessiond_socket = ret;
- connected = 1;
-
- return 0;
-}
-
-/*
- * Clean disconnect the session daemon.
- */
-static int disconnect_sessiond(void)
-{
- int ret = 0;
-
- if (connected) {
- ret = lttcomm_close_unix_sock(sessiond_socket);
- sessiond_socket = 0;
- connected = 0;
- }
-
- return ret;
-}
-
-/*
- * Ask the session daemon a specific command and put the data into buf.
- *
- * Return size of data (only payload, not header).
- */
-static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
-{
- int ret;
- size_t size;
- void *data = NULL;
- struct lttcomm_lttng_msg llm;
-
- ret = connect_sessiond();
- if (ret < 0) {
- goto end;
- }
-
- /* Send command to session daemon */
- ret = send_session_msg(lsm);
- if (ret < 0) {
- goto end;
- }
-
- /* Get header from data transmission */
- ret = recv_data_sessiond(&llm, sizeof(llm));
- if (ret < 0) {
- goto end;
- }
-
- /* Check error code if OK */
- if (llm.ret_code != LTTCOMM_OK) {
- ret = -llm.ret_code;
- goto end;
- }
-
- size = llm.data_size;
- if (size == 0) {
- /* If client free with size 0 */
- if (buf != NULL) {
- *buf = NULL;
- }
- ret = 0;
- goto end;
- }
-
- data = (void*) malloc(size);
-
- /* Get payload data */
- ret = recv_data_sessiond(data, size);
- if (ret < 0) {
- free(data);
- goto end;
- }
-
- /*
- * Extra protection not to dereference a NULL pointer. If buf is NULL at
- * this point, an error is returned and data is freed.
- */
- if (buf == NULL) {
- ret = -1;
- free(data);
- goto end;
- }
-
- *buf = data;
- ret = size;
-
-end:
- disconnect_sessiond();
- return ret;
-}
-
-/*
- * Create lttng handle and return pointer.
- */
-struct lttng_handle *lttng_create_handle(const char *session_name,
- struct lttng_domain *domain)
-{
- struct lttng_handle *handle;
-
- handle = malloc(sizeof(struct lttng_handle));
- if (handle == NULL) {
- perror("malloc handle");
- goto end;
- }
-
- /* Copy session name */
- copy_string(handle->session_name, session_name,
- sizeof(handle->session_name));
-
- /* Copy lttng domain */
- copy_lttng_domain(&handle->domain, domain);
-
-end:
- return handle;
-}
-
-/*
- * Destroy handle by free(3) the pointer.
- */
-void lttng_destroy_handle(struct lttng_handle *handle)
-{
- if (handle) {
- free(handle);
- }
-}
-
-/*
- * Register an outside consumer.
- */
-int lttng_register_consumer(struct lttng_handle *handle,
- const char *socket_path)
-{
- struct lttcomm_session_msg lsm;
-
- lsm.cmd_type = LTTNG_REGISTER_CONSUMER;
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- copy_string(lsm.u.reg.path, socket_path, sizeof(lsm.u.reg.path));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Start tracing for all trace of the session.
- */
-int lttng_start_tracing(const char *session_name)
-{
- struct lttcomm_session_msg lsm;
-
- if (session_name == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_START_TRACE;
-
- copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Stop tracing for all trace of the session.
- */
-int lttng_stop_tracing(const char *session_name)
-{
- struct lttcomm_session_msg lsm;
-
- if (session_name == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_STOP_TRACE;
-
- copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Add context to event or/and channel.
- */
-int lttng_add_context(struct lttng_handle *handle,
- struct lttng_event_context *ctx, const char *event_name,
- const char *channel_name)
-{
- struct lttcomm_session_msg lsm;
-
- /* Safety check. Both are mandatory */
- if (handle == NULL || ctx == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_ADD_CONTEXT;
-
- /* Copy channel name */
- copy_string(lsm.u.context.channel_name, channel_name,
- sizeof(lsm.u.context.channel_name));
- /* Copy event name */
- copy_string(lsm.u.context.event_name, event_name,
- sizeof(lsm.u.context.event_name));
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
-
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Enable event
- */
-int lttng_enable_event(struct lttng_handle *handle,
- struct lttng_event *ev, const char *channel_name)
-{
- struct lttcomm_session_msg lsm;
-
- if (handle == NULL || ev == NULL) {
- return -1;
- }
-
- /* If no channel name, we put the default name */
- if (channel_name == NULL) {
- copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
- sizeof(lsm.u.enable.channel_name));
- } else {
- copy_string(lsm.u.enable.channel_name, channel_name,
- sizeof(lsm.u.enable.channel_name));
- }
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- if (ev->name[0] != '\0') {
- lsm.cmd_type = LTTNG_ENABLE_EVENT;
- } else {
- lsm.cmd_type = LTTNG_ENABLE_ALL_EVENT;
- }
- memcpy(&lsm.u.enable.event, ev, sizeof(lsm.u.enable.event));
-
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Disable event of a channel and domain.
- */
-int lttng_disable_event(struct lttng_handle *handle, const char *name,
- const char *channel_name)
-{
- struct lttcomm_session_msg lsm;
-
- if (handle == NULL) {
- return -1;
- }
-
- if (channel_name) {
- copy_string(lsm.u.disable.channel_name, channel_name,
- sizeof(lsm.u.disable.channel_name));
- } else {
- copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME,
- sizeof(lsm.u.disable.channel_name));
- }
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- if (name != NULL) {
- copy_string(lsm.u.disable.name, name, sizeof(lsm.u.disable.name));
- lsm.cmd_type = LTTNG_DISABLE_EVENT;
- } else {
- lsm.cmd_type = LTTNG_DISABLE_ALL_EVENT;
- }
-
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Enable channel per domain
- */
-int lttng_enable_channel(struct lttng_handle *handle,
- struct lttng_channel *chan)
-{
- struct lttcomm_session_msg lsm;
-
- /*
- * NULL arguments are forbidden. No default values.
- */
- if (handle == NULL || chan == NULL) {
- return -1;
- }
-
- memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
-
- lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * All tracing will be stopped for registered events of the channel.
- */
-int lttng_disable_channel(struct lttng_handle *handle, const char *name)
-{
- struct lttcomm_session_msg lsm;
-
- /* Safety check. Both are mandatory */
- if (handle == NULL || name == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
-
- copy_string(lsm.u.disable.channel_name, name,
- sizeof(lsm.u.disable.channel_name));
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * List all available tracepoints of domain.
- *
- * Return the size (bytes) of the list and set the events array.
- * On error, return negative value.
- */
-int lttng_list_tracepoints(struct lttng_handle *handle,
- struct lttng_event **events)
-{
- int ret;
- struct lttcomm_session_msg lsm;
-
- if (handle == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- ret = ask_sessiond(&lsm, (void **) events);
- if (ret < 0) {
- return ret;
- }
-
- return ret / sizeof(struct lttng_event);
-}
-
-/*
- * Return a human readable string of code
- */
-const char *lttng_strerror(int code)
-{
- if (code > -LTTCOMM_OK) {
- return "Ended with errors";
- }
-
- return lttcomm_get_readable_code(code);
-}
-
-/*
- * Create a brand new session using name.
- */
-int lttng_create_session(const char *name, const char *path)
-{
- struct lttcomm_session_msg lsm;
-
- lsm.cmd_type = LTTNG_CREATE_SESSION;
- copy_string(lsm.session.name, name, sizeof(lsm.session.name));
- copy_string(lsm.session.path, path, sizeof(lsm.session.path));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Destroy session using name.
- */
-int lttng_destroy_session(const char *session_name)
-{
- struct lttcomm_session_msg lsm;
-
- if (session_name == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_DESTROY_SESSION;
-
- copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Ask the session daemon for all available sessions.
- *
- * Return number of session.
- * On error, return negative value.
- */
-int lttng_list_sessions(struct lttng_session **sessions)
-{
- int ret;
- struct lttcomm_session_msg lsm;
-
- lsm.cmd_type = LTTNG_LIST_SESSIONS;
- ret = ask_sessiond(&lsm, (void**) sessions);
- if (ret < 0) {
- return ret;
- }
-
- return ret / sizeof(struct lttng_session);
-}
-
-/*
- * List domain of a session.
- */
-int lttng_list_domains(const char *session_name,
- struct lttng_domain **domains)
-{
- int ret;
- struct lttcomm_session_msg lsm;
-
- if (session_name == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_LIST_DOMAINS;
-
- copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
-
- ret = ask_sessiond(&lsm, (void**) domains);
- if (ret < 0) {
- return ret;
- }
-
- return ret / sizeof(struct lttng_domain);
-}
-
-/*
- * List channels of a session
- */
-int lttng_list_channels(struct lttng_handle *handle,
- struct lttng_channel **channels)
-{
- int ret;
- struct lttcomm_session_msg lsm;
-
- if (handle == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_LIST_CHANNELS;
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- ret = ask_sessiond(&lsm, (void**) channels);
- if (ret < 0) {
- return ret;
- }
-
- return ret / sizeof(struct lttng_channel);
-}
-
-/*
- * List events of a session channel.
- */
-int lttng_list_events(struct lttng_handle *handle,
- const char *channel_name, struct lttng_event **events)
-{
- int ret;
- struct lttcomm_session_msg lsm;
-
- /* Safety check. An handle and channel name are mandatory */
- if (handle == NULL || channel_name == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_LIST_EVENTS;
- copy_string(lsm.session.name, handle->session_name,
- sizeof(lsm.session.name));
- copy_string(lsm.u.list.channel_name, channel_name,
- sizeof(lsm.u.list.channel_name));
-
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- ret = ask_sessiond(&lsm, (void**) events);
- if (ret < 0) {
- return ret;
- }
-
- return ret / sizeof(struct lttng_event);
-}
-
-/*
- * Set tracing group variable with name. This function allocate memory pointed
- * by tracing_group.
- */
-int lttng_set_tracing_group(const char *name)
-{
- if (name == NULL) {
- return -1;
- }
-
- if (asprintf(&tracing_group, "%s", name) < 0) {
- return -ENOMEM;
- }
-
- return 0;
-}
-
-/*
- * lttng_calibrate
- */
-int lttng_calibrate(struct lttng_handle *handle,
- struct lttng_calibrate *calibrate)
-{
- struct lttcomm_session_msg lsm;
-
- /* Safety check. NULL pointer are forbidden */
- if (handle == NULL || calibrate == NULL) {
- return -1;
- }
-
- lsm.cmd_type = LTTNG_CALIBRATE;
- copy_lttng_domain(&lsm.domain, &handle->domain);
-
- memcpy(&lsm.u.calibrate, calibrate, sizeof(lsm.u.calibrate));
-
- return ask_sessiond(&lsm, NULL);
-}
-
-/*
- * Set default channel attributes.
- */
-void lttng_channel_set_default_attr(struct lttng_domain *domain,
- struct lttng_channel_attr *attr)
-{
- /* Safety check */
- if (attr == NULL || domain == NULL) {
- return;
- }
-
- switch (domain->type) {
- case LTTNG_DOMAIN_KERNEL:
- attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
- attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
- attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
-
- attr->subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
- attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
- attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
- break;
- case LTTNG_DOMAIN_UST:
- case LTTNG_DOMAIN_UST_EXEC_NAME:
- case LTTNG_DOMAIN_UST_PID:
- case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
- attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
- attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
- attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
-
- attr->subbuf_size = DEFAULT_UST_CHANNEL_SUBBUF_SIZE;
- attr->num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM;
- attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
- break;
- default:
- /* Default behavior */
- memset(attr, 0, sizeof(struct lttng_channel_attr));
- break;
- }
-}
-
-/*
- * Check if session daemon is alive.
- *
- * Return 1 if alive or 0 if not.
- * On error return -1
- */
-int lttng_session_daemon_alive(void)
-{
- int ret;
-
- ret = set_session_daemon_path();
- if (ret < 0) {
- /* Error */
- return ret;
- }
-
- if (strlen(sessiond_sock_path) == 0) {
- /* No socket path set. Weird error */
- return -1;
- }
-
- ret = try_connect_sessiond(sessiond_sock_path);
- if (ret < 0) {
- /* Not alive */
- return 0;
- }
-
- /* Is alive */
- return 1;
-}
-
-/*
- * lib constructor
- */
-static void __attribute__((constructor)) init()
-{
- /* Set default session group */
- lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP);
-}
projects / lttng-tools.git / blobdiff