X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=ltt-sessiond%2Fmain.c;h=0effeb1f5ab51a0c91973505c7efd9629dee5a3c;hp=418875a2aa453313406f8d0f4b92594c80049bd9;hb=2b1173d8cb43cb5d7c9ce3772dbdbef3436c407e;hpb=5b74c7b1ca96399ba5c8bd0ce6974aea671198eb diff --git a/ltt-sessiond/main.c b/ltt-sessiond/main.c index 418875a2a..0effeb1f5 100644 --- a/ltt-sessiond/main.c +++ b/ltt-sessiond/main.c @@ -5,12 +5,12 @@ * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. - * + * * This program 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 General Public License for more details. - * + * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. @@ -22,255 +22,285 @@ #include #include #include +#include #include #include #include #include #include +#include #include #include #include #include +#include +#include #include #include /* URCU list library (-lurcu) */ -#include /* UST control lib (-lust) */ -#include +#include #include "liblttsessiondcomm.h" #include "ltt-sessiond.h" #include "lttngerr.h" +#include "kernel-ctl.h" +#include "ust-ctl.h" #include "session.h" +#include "traceable-app.h" +#include "lttng-kconsumerd.h" +#include "libustctl.h" +#include "utils.h" + +/* + * TODO: + * teardown: signal SIGTERM handler -> write into pipe. Threads waits + * with epoll on pipe and on other pipes/sockets for commands. Main + * simply waits on pthread join. + */ /* Const values */ const char default_home_dir[] = DEFAULT_HOME_DIR; -const char default_tracing_group[] = DEFAULT_TRACING_GROUP; +const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP; const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR; const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE; -/* Static functions */ -static int set_signal_handler(void); -static int set_socket_perms(void); -static void sighandler(int sig); -static void cleanup(void); -static void copy_common_data(struct lttcomm_lttng_msg *llm, struct lttcomm_session_msg *lsm); -static int check_existing_daemon(void); -static int notify_apps(const char* name); -static int connect_app(pid_t pid); -static int find_app_by_pid(pid_t pid); -static int init_daemon_socket(void); -static int process_client_msg(int sock, struct lttcomm_session_msg*); -static int send_unix_sock(int sock, void *buf, size_t len); -static int setup_data_buffer(char **buf, size_t size, struct lttcomm_lttng_msg *llm); -static void add_traceable_app(struct ltt_traceable_app *lta); -static void del_traceable_app(struct ltt_traceable_app *lta); - -/* Command function */ -static void get_list_apps(pid_t *pids); - -static void *thread_manage_clients(void *data); -static void *thread_manage_apps(void *data); - /* Variables */ +int opt_verbose; /* Not static for lttngerr.h */ +int opt_quiet; /* Not static for lttngerr.h */ const char *progname; const char *opt_tracing_group; static int opt_sig_parent; static int opt_daemon; -int opt_verbose; -int opt_quiet; static int is_root; /* Set to 1 if the daemon is running as root */ -static pid_t ppid; +static pid_t ppid; /* Parent PID for --sig-parent option */ +static pid_t kconsumerd_pid; -static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */ -static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */ +static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */ +static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */ +static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */ +static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */ -static int client_socket; -static int apps_socket; +/* Sockets and FDs */ +static int client_sock; +static int apps_sock; +static int kconsumerd_err_sock; +static int kconsumerd_cmd_sock; +static int kernel_tracer_fd; -static struct ltt_session *current_session; +/* Pthread, Mutexes and Semaphores */ +static pthread_t kconsumerd_thread; +static pthread_t apps_thread; +static pthread_t client_thread; +static sem_t kconsumerd_sem; -/* Number of element for the list below. */ -static unsigned int traceable_app_count; +static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */ -/* Init ust traceabl application's list */ -static struct ltt_traceable_app_list ltt_traceable_app_list = { - .head = CDS_LIST_HEAD_INIT(ltt_traceable_app_list.head), -}; - -/* List mutex */ -pthread_mutex_t ltt_traceable_app_list_mutex; +/* + * teardown_kernel_session + * + * Complete teardown of a kernel session. This free all data structure + * related to a kernel session and update counter. + */ +static void teardown_kernel_session(struct ltt_session *session) +{ + if (session->kernel_session != NULL) { + DBG("Tearing down kernel session"); + trace_destroy_kernel_session(session->kernel_session); + /* Extra precaution */ + session->kernel_session = NULL; + /* Decrement session count */ + session->kern_session_count--; + } +} /* - * thread_manage_apps + * cleanup * - * This thread manage the application socket communication + * Cleanup the daemon on exit */ -static void *thread_manage_apps(void *data) +static void cleanup() { - int sock, ret; - struct ltt_traceable_app *lta; + int ret; + char *cmd; + struct ltt_session *sess; - /* TODO: Something more elegant is needed but fine for now */ - struct { - int reg; /* 1:register, 0:unregister */ - pid_t pid; - uid_t uid; - } reg_msg; + DBG("Cleaning up"); - /* Notify all applications to register */ - notify_apps(default_global_apps_pipe); + /* */ + MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0); + MSG("%c[%d;%dmMatthew, BEET driven development works!%c[%dm",27,1,33,27,0); + /* */ - ret = lttcomm_listen_unix_sock(apps_socket); + /* Stopping all threads */ + DBG("Terminating all threads"); + pthread_cancel(client_thread); + pthread_cancel(apps_thread); + if (kconsumerd_pid != 0) { + pthread_cancel(kconsumerd_thread); + } + + DBG("Unlinking all unix socket"); + unlink(client_unix_sock_path); + unlink(apps_unix_sock_path); + unlink(kconsumerd_err_unix_sock_path); + + DBG("Removing %s directory", LTTNG_RUNDIR); + ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR); if (ret < 0) { - goto error; + ERR("asprintf failed. Something is really wrong!"); } - while (1) { - /* Blocking call, waiting for transmission */ - sock = lttcomm_accept_unix_sock(apps_socket); - if (sock < 0) { - goto error; - } + /* Remove lttng run directory */ + ret = system(cmd); + if (ret < 0) { + ERR("Unable to clean " LTTNG_RUNDIR); + } - /* Basic recv here to handle the very simple data - * that the libust send to register (reg_msg). - */ - ret = recv(sock, ®_msg, sizeof(reg_msg), 0); - if (ret < 0) { - perror("recv"); - continue; - } + DBG("Cleaning up all session"); + /* Cleanup ALL session */ + cds_list_for_each_entry(sess, <t_session_list.head, list) { + teardown_kernel_session(sess); + // TODO complete session cleanup (including UST) + } - /* Add application to the global traceable list */ - if (reg_msg.reg == 1) { - /* Registering */ - lta = malloc(sizeof(struct ltt_traceable_app)); - lta->pid = reg_msg.pid; - lta->uid = reg_msg.uid; - add_traceable_app(lta); - } else { - /* Unregistering */ - cds_list_for_each_entry(lta, <t_traceable_app_list.head, list) { - if (lta->pid == reg_msg.pid && lta->uid == reg_msg.uid) { - del_traceable_app(lta); - free(lta); - break; - } - } - } + DBG("Closing kernel fd"); + close(kernel_tracer_fd); +} + +/* + * send_unix_sock + * + * Send data on a unix socket using the liblttsessiondcomm API. + * + * Return lttcomm error code. + */ +static int send_unix_sock(int sock, void *buf, size_t len) +{ + /* Check valid length */ + if (len <= 0) { + return -1; } -error: + return lttcomm_send_unix_sock(sock, buf, len); +} - return NULL; +/* + * clean_command_ctx + * + * Free memory of a command context structure. + */ +static void clean_command_ctx(struct command_ctx *cmd_ctx) +{ + DBG("Clean command context structure %p", cmd_ctx); + if (cmd_ctx) { + if (cmd_ctx->llm) { + free(cmd_ctx->llm); + } + if (cmd_ctx->lsm) { + free(cmd_ctx->lsm); + } + free(cmd_ctx); + cmd_ctx = NULL; + } } /* - * thread_manage_clients + * send_kconsumerd_fds * - * This thread manage all clients request using the unix - * client socket for communication. + * Send all stream fds of the kernel session to the consumer. */ -static void *thread_manage_clients(void *data) +static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session) { - int sock, ret; - struct lttcomm_session_msg lsm; + int ret; + size_t nb_fd; + struct ltt_kernel_stream *stream; + struct ltt_kernel_channel *chan; + struct lttcomm_kconsumerd_header lkh; + struct lttcomm_kconsumerd_msg lkm; + + nb_fd = session->stream_count_global; + + /* Setup header */ + lkh.payload_size = (nb_fd + 1) * sizeof(struct lttcomm_kconsumerd_msg); + lkh.cmd_type = ADD_STREAM; + + DBG("Sending kconsumerd header"); - ret = lttcomm_listen_unix_sock(client_socket); + ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header)); if (ret < 0) { + perror("send kconsumerd header"); goto error; } - /* Notify parent pid that we are ready - * to accept command for client side. - */ - if (opt_sig_parent) { - kill(ppid, SIGCHLD); + DBG("Sending metadata stream fd"); + + /* Send metadata stream fd first */ + lkm.fd = session->metadata_stream_fd; + lkm.state = ACTIVE_FD; + lkm.max_sb_size = session->metadata->conf->attr.subbuf_size; + strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX); + + ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm)); + if (ret < 0) { + perror("send kconsumerd fd"); + goto error; } - while (1) { - /* Blocking call, waiting for transmission */ - sock = lttcomm_accept_unix_sock(client_socket); - if (sock < 0) { - goto error; - } + cds_list_for_each_entry(chan, &session->channel_list.head, list) { + cds_list_for_each_entry(stream, &chan->stream_list.head, list) { + lkm.fd = stream->fd; + lkm.state = stream->state; + lkm.max_sb_size = chan->channel->attr.subbuf_size; + strncpy(lkm.path_name, stream->pathname, PATH_MAX); - /* - * Data is received from the lttng client. The struct - * lttcomm_session_msg (lsm) contains the command and data - * request of the client. - */ - ret = lttcomm_recv_unix_sock(sock, &lsm, sizeof(lsm)); - if (ret <= 0) { - continue; - } + DBG("Sending fd %d to kconsumerd", lkm.fd); - /* This function dispatch the work to the LTTng or UST libs - * and then sends back the response to the client. This is needed - * because there might be more then one lttcomm_lttng_msg to - * send out so process_client_msg do both jobs. - */ - ret = process_client_msg(sock, &lsm); - if (ret < 0) { - /* Error detected but still accept command */ - continue; + ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm)); + if (ret < 0) { + perror("send kconsumerd fd"); + goto error; + } } } + DBG("Kconsumerd fds sent"); + + return 0; + error: - return NULL; + return ret; } /* - * add_traceable_app + * create_trace_dir * - * Add a traceable application structure to the global - * list protected by a mutex. + * Create the trace output directory. */ -static void add_traceable_app(struct ltt_traceable_app *lta) +static int create_trace_dir(struct ltt_kernel_session *session) { - pthread_mutex_lock(<t_traceable_app_list_mutex); - cds_list_add(<a->list, <t_traceable_app_list.head); - traceable_app_count++; - pthread_mutex_unlock(<t_traceable_app_list_mutex); -} + int ret; + struct ltt_kernel_channel *chan; -/* - * del_traceable_app - * - * Delete a traceable application structure from the - * global list protected by a mutex. - */ -static void del_traceable_app(struct ltt_traceable_app *lta) -{ - pthread_mutex_lock(<t_traceable_app_list_mutex); - cds_list_del(<a->list); - /* Sanity check */ - if (traceable_app_count != 0) { - traceable_app_count--; + /* Create all channel directories */ + cds_list_for_each_entry(chan, &session->channel_list.head, list) { + DBG("Creating trace directory at %s", chan->pathname); + ret = mkdir_recursive(chan->pathname, S_IRWXU | S_IRWXG ); + if (ret < 0) { + if (ret != EEXIST) { + ERR("Trace directory creation error"); + goto error; + } + } } - pthread_mutex_unlock(<t_traceable_app_list_mutex); -} -/* - * send_unix_sock - * - * Send data on a unix socket using the liblttsessiondcomm API. - * - * Return lttcomm error code. - */ -static int send_unix_sock(int sock, void *buf, size_t len) -{ - /* Check valid length */ - if (len <= 0) { - return -1; - } + return 0; - return lttcomm_send_unix_sock(sock, buf, len); +error: + return ret; } /* - * connect_app + * ust_connect_app * * Return a socket connected to the libust communication socket * of the application identified by the pid. @@ -278,18 +308,23 @@ static int send_unix_sock(int sock, void *buf, size_t len) * If the pid is not found in the traceable list, * return -1 to indicate error. */ -static int connect_app(pid_t pid) +static int ust_connect_app(pid_t pid) { - int sock, ret; + int sock; + struct ltt_traceable_app *lta; - ret = find_app_by_pid(pid); - if (ret == 0) { + DBG("Connect to application pid %d", pid); + + lta = find_app_by_pid(pid); + if (lta == NULL) { + /* App not found */ + DBG("Application pid %d not found", pid); return -1; } - sock = ustctl_connect_pid(pid); + sock = ustctl_connect_pid(lta->pid); if (sock < 0) { - ERR("Fail connecting to the PID %d\n", pid); + ERR("Fail connecting to the PID %d", pid); } return sock; @@ -309,6 +344,8 @@ static int notify_apps(const char *name) int fd; int ret = -1; + DBG("Notify the global application pipe"); + /* Try opening the global pipe */ fd = open(name, O_WRONLY); if (fd < 0) { @@ -326,313 +363,1367 @@ error: } /* - * find_app_by_pid + * setup_lttng_msg + * + * Setup the outgoing data buffer for the response (llm) by allocating the + * right amount of memory and copying the original information from the lsm + * structure. * - * Iterate over the traceable apps list. - * On success, return 1, else return 0 + * Return total size of the buffer pointed by buf. */ -static int find_app_by_pid(pid_t pid) +static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size) { - struct ltt_traceable_app *iter; + int ret, buf_size; - pthread_mutex_lock(<t_traceable_app_list_mutex); - cds_list_for_each_entry(iter, <t_traceable_app_list.head, list) { - if (iter->pid == pid) { - pthread_mutex_unlock(<t_traceable_app_list_mutex); - /* Found */ - return 1; - } + buf_size = size; + + cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size); + if (cmd_ctx->llm == NULL) { + perror("malloc"); + ret = -ENOMEM; + goto error; } - pthread_mutex_unlock(<t_traceable_app_list_mutex); - return 0; + /* Copy common data */ + cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type; + cmd_ctx->llm->pid = cmd_ctx->lsm->pid; + + cmd_ctx->llm->data_size = size; + cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size; + + return buf_size; + +error: + return ret; } /* - * ust_create_trace + * thread_manage_kconsumerd * - * Create an userspace trace using pid. - * This trace is then appended to the current session - * ust trace list. + * This thread manage the kconsumerd error sent + * back to the session daemon. */ -static int ust_create_trace(pid_t pid) +static void *thread_manage_kconsumerd(void *data) { int sock, ret; - struct ltt_ust_trace *trace; + enum lttcomm_return_code code; - trace = malloc(sizeof(struct ltt_ust_trace)); - if (trace == NULL) { - perror("malloc"); - ret = -1; + DBG("[thread] Manage kconsumerd started"); + + ret = lttcomm_listen_unix_sock(kconsumerd_err_sock); + if (ret < 0) { goto error; } - /* Init */ - trace->pid = pid; - trace->shmid = 0; - - /* Connect to app using ustctl API */ - sock = connect_app(pid); + sock = lttcomm_accept_unix_sock(kconsumerd_err_sock); if (sock < 0) { - ret = LTTCOMM_NO_TRACEABLE; goto error; } - ret = ustctl_create_trace(sock, "auto"); + /* Getting status code from kconsumerd */ + ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code)); + if (ret <= 0) { + goto error; + } + + if (code == KCONSUMERD_COMMAND_SOCK_READY) { + kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path); + if (kconsumerd_cmd_sock < 0) { + sem_post(&kconsumerd_sem); + perror("kconsumerd connect"); + goto error; + } + /* Signal condition to tell that the kconsumerd is ready */ + sem_post(&kconsumerd_sem); + DBG("Kconsumerd command socket ready"); + } else { + DBG("Kconsumerd error when waiting for SOCK_READY : %s", + lttcomm_get_readable_code(-code)); + goto error; + } + + /* Wait for any kconsumerd error */ + ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code)); + if (ret <= 0) { + ERR("Kconsumerd closed the command socket"); + goto error; + } + + ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code)); + +error: + kconsumerd_pid = 0; + DBG("Kconsumerd thread dying"); + return NULL; +} + +/* + * thread_manage_apps + * + * This thread manage the application socket communication + */ +static void *thread_manage_apps(void *data) +{ + int sock, ret; + + /* TODO: Something more elegant is needed but fine for now */ + /* FIXME: change all types to either uint8_t, uint32_t, uint64_t + * for 32-bit vs 64-bit compat processes. */ + /* replicate in ust with version number */ + struct { + int reg; /* 1:register, 0:unregister */ + pid_t pid; + uid_t uid; + } reg_msg; + + DBG("[thread] Manage apps started"); + + ret = lttcomm_listen_unix_sock(apps_sock); if (ret < 0) { - ret = LTTCOMM_CREATE_FAIL; goto error; } - /* Check if current session is valid */ - if (current_session) { - cds_list_add(&trace->list, ¤t_session->ust_traces); + /* Notify all applications to register */ + notify_apps(default_global_apps_pipe); + + while (1) { + DBG("Accepting application registration"); + /* Blocking call, waiting for transmission */ + sock = lttcomm_accept_unix_sock(apps_sock); + if (sock < 0) { + goto error; + } + + /* Basic recv here to handle the very simple data + * that the libust send to register (reg_msg). + */ + ret = recv(sock, ®_msg, sizeof(reg_msg), 0); + if (ret < 0) { + perror("recv"); + continue; + } + + /* Add application to the global traceable list */ + if (reg_msg.reg == 1) { + /* Registering */ + ret = register_traceable_app(reg_msg.pid, reg_msg.uid); + if (ret < 0) { + /* register_traceable_app only return an error with + * ENOMEM. At this point, we better stop everything. + */ + goto error; + } + } else { + /* Unregistering */ + unregister_traceable_app(reg_msg.pid); + } } error: - return ret; + + return NULL; } /* - * get_list_apps + * spawn_kconsumerd_thread * - * List traceable user-space application and fill an - * array of pids. + * Start the thread_manage_kconsumerd. This must be done after a kconsumerd + * exec or it will fails. */ -static void get_list_apps(pid_t *pids) +static int spawn_kconsumerd_thread(void) { - int i = 0; - struct ltt_traceable_app *iter; + int ret; + + /* Setup semaphore */ + sem_init(&kconsumerd_sem, 0, 0); + + ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL); + if (ret != 0) { + perror("pthread_create kconsumerd"); + goto error; + } + + /* Wait for the kconsumerd thread to be ready */ + sem_wait(&kconsumerd_sem); + + if (kconsumerd_pid == 0) { + ERR("Kconsumerd did not start"); + goto error; + } + + return 0; + +error: + ret = LTTCOMM_KERN_CONSUMER_FAIL; + return ret; +} + +/* + * spawn_kconsumerd + * + * Fork and exec a kernel consumer daemon (kconsumerd). + * + * NOTE: It is very important to fork a kconsumerd BEFORE opening any kernel + * file descriptor using the libkernelctl or kernel-ctl functions. So, a + * kernel consumer MUST only be spawned before creating a kernel session. + * + * Return pid if successful else -1. + */ +static pid_t spawn_kconsumerd(void) +{ + int ret; + pid_t pid; + + DBG("Spawning kconsumerd"); + + pid = fork(); + if (pid == 0) { + /* + * Exec kconsumerd. + */ + execlp("ltt-kconsumerd", "ltt-kconsumerd", "--verbose", NULL); + if (errno != 0) { + perror("kernel start consumer exec"); + } + exit(EXIT_FAILURE); + } else if (pid > 0) { + ret = pid; + goto error; + } else { + perror("kernel start consumer fork"); + ret = -errno; + goto error; + } + +error: + return ret; +} + +/* + * start_kconsumerd + * + * Spawn the kconsumerd daemon and session daemon thread. + */ +static int start_kconsumerd(void) +{ + int ret; + + pthread_mutex_lock(&kconsumerd_pid_mutex); + if (kconsumerd_pid != 0) { + goto end; + } + + ret = spawn_kconsumerd(); + if (ret < 0) { + ERR("Spawning kconsumerd failed"); + ret = LTTCOMM_KERN_CONSUMER_FAIL; + pthread_mutex_unlock(&kconsumerd_pid_mutex); + goto error; + } + + /* Setting up the global kconsumerd_pid */ + kconsumerd_pid = ret; + pthread_mutex_unlock(&kconsumerd_pid_mutex); + + DBG("Kconsumerd pid %d", ret); + + DBG("Spawning kconsumerd thread"); + ret = spawn_kconsumerd_thread(); + if (ret < 0) { + ERR("Fatal error spawning kconsumerd thread"); + goto error; + } + +end: + pthread_mutex_unlock(&kconsumerd_pid_mutex); + return 0; + +error: + return ret; +} + +/* + * modprobe_kernel_modules + */ +static int modprobe_kernel_modules(void) +{ + int ret = 0, i = 0; + char modprobe[256]; + + while (kernel_modules_list[i] != NULL) { + ret = snprintf(modprobe, sizeof(modprobe), "/sbin/modprobe %s", + kernel_modules_list[i]); + if (ret < 0) { + perror("snprintf modprobe"); + goto error; + } + ret = system(modprobe); + if (ret < 0) { + ERR("Unable to load module %s", kernel_modules_list[i]); + } + DBG("Modprobe successfully %s", kernel_modules_list[i]); + i++; + } + +error: + return ret; +} + +/* + * mount_debugfs + */ +static int mount_debugfs(char *path) +{ + int ret; + char *type = "debugfs"; + + ret = mkdir_recursive(path, S_IRWXU | S_IRWXG); + if (ret < 0) { + goto error; + } + + ret = mount(type, path, type, 0, NULL); + if (ret < 0) { + perror("mount debugfs"); + goto error; + } + + DBG("Mounted debugfs successfully at %s", path); + +error: + return ret; +} + +/* + * init_kernel_tracer + * + * Setup necessary data for kernel tracer action. + */ +static void init_kernel_tracer(void) +{ + int ret; + char *proc_mounts = "/proc/mounts"; + char line[256]; + char *debugfs_path = NULL, *lttng_path; + FILE *fp; + + /* Detect debugfs */ + fp = fopen(proc_mounts, "r"); + if (fp == NULL) { + ERR("Unable to probe %s", proc_mounts); + goto error; + } + + while (fgets(line, sizeof(line), fp) != NULL) { + if (strstr(line, "debugfs") != NULL) { + /* Remove first string */ + strtok(line, " "); + /* Dup string here so we can reuse line later on */ + debugfs_path = strdup(strtok(NULL, " ")); + DBG("Got debugfs path : %s", debugfs_path); + break; + } + } + + fclose(fp); + + /* Mount debugfs if needded */ + if (debugfs_path == NULL) { + ret = asprintf(&debugfs_path, "/mnt/debugfs"); + if (ret < 0) { + perror("asprintf debugfs path"); + goto error; + } + ret = mount_debugfs(debugfs_path); + if (ret < 0) { + goto error; + } + } + + /* Modprobe lttng kernel modules */ + ret = modprobe_kernel_modules(); + if (ret < 0) { + goto error; + } + + /* Setup lttng kernel path */ + ret = asprintf(<tng_path, "%s/lttng", debugfs_path); + if (ret < 0) { + perror("asprintf lttng path"); + goto error; + } + + /* Open debugfs lttng */ + kernel_tracer_fd = open(lttng_path, O_RDWR); + if (kernel_tracer_fd < 0) { + DBG("Failed to open %s", lttng_path); + goto error; + } + + free(lttng_path); + free(debugfs_path); + DBG("Kernel tracer fd %d", kernel_tracer_fd); + return; + +error: + if (lttng_path) { + free(lttng_path); + } + if (debugfs_path) { + free(debugfs_path); + } + WARN("No kernel tracer available"); + kernel_tracer_fd = 0; + return; +} + +/* + * start_kernel_trace + * + * Start tracing by creating trace directory and sending FDs to the kernel + * consumer. + */ +static int start_kernel_trace(struct ltt_kernel_session *session) +{ + int ret; + + /* Create trace directory */ + ret = create_trace_dir(session); + if (ret < 0) { + if (ret == -EEXIST) { + ret = LTTCOMM_KERN_DIR_EXIST; + } else { + ret = LTTCOMM_KERN_DIR_FAIL; + goto error; + } + } + + if (session->kconsumer_fds_sent == 0) { + ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session); + if (ret < 0) { + ERR("Send kconsumerd fds failed"); + ret = LTTCOMM_KERN_CONSUMER_FAIL; + goto error; + } + + session->kconsumer_fds_sent = 1; + } + +error: + return ret; +} + +/* + * init_default_channel + * + * Allocate a channel structure and fill it. + */ +static struct lttng_channel *init_default_channel(void) +{ + struct lttng_channel *chan; + + chan = malloc(sizeof(struct lttng_channel)); + if (chan == NULL) { + perror("init channel malloc"); + goto error; + } + + if (snprintf(chan->name, NAME_MAX, DEFAULT_CHANNEL_NAME) < 0) { + perror("snprintf defautl channel name"); + return NULL; + } + + chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE; + chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE; + chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM; + chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER; + chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER; + chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT; + +error: + return chan; +} + +/* + * create_kernel_session + * + * Create a kernel tracer session then create the default channel. + */ +static int create_kernel_session(struct ltt_session *session) +{ + int ret; + struct lttng_channel *chan; + + DBG("Creating kernel session"); + + ret = kernel_create_session(session, kernel_tracer_fd); + if (ret < 0) { + ret = LTTCOMM_KERN_SESS_FAIL; + goto error; + } + + chan = init_default_channel(); + if (chan == NULL) { + ret = LTTCOMM_FATAL; + goto error; + } + + DBG("Creating default kernel channel %s", DEFAULT_CHANNEL_NAME); + + ret = kernel_create_channel(session->kernel_session, chan, session->path); + if (ret < 0) { + ret = LTTCOMM_KERN_CHAN_FAIL; + goto error; + } + +error: + return ret; +} + +/* + * process_client_msg + * + * Process the command requested by the lttng client within the command + * context structure. This function make sure that the return structure (llm) + * is set and ready for transmission before returning. + * + * Return any error encountered or 0 for success. + */ +static int process_client_msg(struct command_ctx *cmd_ctx) +{ + int ret; + + DBG("Processing client command %d", cmd_ctx->lsm->cmd_type); + + /* Listing commands don't need a session */ + switch (cmd_ctx->lsm->cmd_type) { + case LTTNG_CREATE_SESSION: + case LTTNG_LIST_SESSIONS: + case LTTNG_LIST_EVENTS: + case LTTNG_KERNEL_LIST_EVENTS: + case LTTNG_LIST_TRACEABLE_APPS: + break; + default: + DBG("Getting session %s by name", cmd_ctx->lsm->session_name); + cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session_name); + if (cmd_ctx->session == NULL) { + /* If session name not found */ + if (cmd_ctx->lsm->session_name != NULL) { + ret = LTTCOMM_SESS_NOT_FOUND; + } else { /* If no session name specified */ + ret = LTTCOMM_SELECT_SESS; + } + goto error; + } + break; + } + + /* + * Check kernel command for kernel session. + */ + switch (cmd_ctx->lsm->cmd_type) { + case LTTNG_KERNEL_ADD_CONTEXT: + case LTTNG_KERNEL_CREATE_CHANNEL: + case LTTNG_KERNEL_DISABLE_ALL_EVENT: + case LTTNG_KERNEL_DISABLE_CHANNEL: + case LTTNG_KERNEL_DISABLE_EVENT: + case LTTNG_KERNEL_ENABLE_ALL_EVENT: + case LTTNG_KERNEL_ENABLE_CHANNEL: + case LTTNG_KERNEL_ENABLE_EVENT: + case LTTNG_KERNEL_LIST_EVENTS: + /* Kernel tracer check */ + if (kernel_tracer_fd == 0) { + init_kernel_tracer(); + if (kernel_tracer_fd == 0) { + ret = LTTCOMM_KERN_NA; + goto error; + } + } + + /* Need a session for kernel command */ + if (cmd_ctx->lsm->cmd_type != LTTNG_KERNEL_LIST_EVENTS && + cmd_ctx->session->kernel_session == NULL) { + + ret = create_kernel_session(cmd_ctx->session); + if (ret < 0) { + ret = LTTCOMM_KERN_SESS_FAIL; + goto error; + } + + /* Start the kernel consumer daemon */ + if (kconsumerd_pid == 0) { + ret = start_kconsumerd(); + if (ret < 0) { + goto error; + } + } + } + } + + /* Connect to ust apps if available pid */ + if (cmd_ctx->lsm->pid > 0) { + /* Connect to app using ustctl API */ + cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid); + if (cmd_ctx->ust_sock < 0) { + ret = LTTCOMM_NO_TRACEABLE; + goto error; + } + } + + /* Process by command type */ + switch (cmd_ctx->lsm->cmd_type) { + case LTTNG_KERNEL_ADD_CONTEXT: + { + int found = 0, no_event = 0; + struct ltt_kernel_channel *chan; + struct ltt_kernel_event *event; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + /* Check if event name is given */ + if (strlen(cmd_ctx->lsm->u.context.event_name) == 0) { + no_event = 1; + } + + if (strlen(cmd_ctx->lsm->u.context.channel_name) == 0) { + /* Go over all channels */ + DBG("Adding context to all channels"); + cds_list_for_each_entry(chan, + &cmd_ctx->session->kernel_session->channel_list.head, list) { + if (no_event) { + ret = kernel_add_channel_context(chan, + &cmd_ctx->lsm->u.context.ctx); + if (ret < 0) { + continue; + } + } else { + event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan); + if (event != NULL) { + ret = kernel_add_event_context(event, + &cmd_ctx->lsm->u.context.ctx); + if (ret < 0) { + ret = LTTCOMM_KERN_CONTEXT_FAIL; + goto error; + } + found = 1; + break; + } + } + } + } else { + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.context.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } + + if (no_event) { + ret = kernel_add_channel_context(chan, + &cmd_ctx->lsm->u.context.ctx); + if (ret < 0) { + ret = LTTCOMM_KERN_CONTEXT_FAIL; + goto error; + } + } else { + event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan); + if (event != NULL) { + ret = kernel_add_event_context(event, + &cmd_ctx->lsm->u.context.ctx); + if (ret < 0) { + ret = LTTCOMM_KERN_CONTEXT_FAIL; + goto error; + } + } + } + } + + if (!found && !no_event) { + ret = LTTCOMM_NO_EVENT; + goto error; + } + + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_CREATE_CHANNEL: + { + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + /* Kernel tracer */ + DBG("Creating kernel channel"); + + ret = kernel_create_channel(cmd_ctx->session->kernel_session, + &cmd_ctx->lsm->u.channel.chan, cmd_ctx->session->path); + if (ret < 0) { + ret = LTTCOMM_KERN_CHAN_FAIL; + goto error; + } + + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_DISABLE_CHANNEL: + { + struct ltt_kernel_channel *chan; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } else if (chan->enabled == 1) { + ret = kernel_disable_channel(chan); + if (ret < 0) { + if (ret != EEXIST) { + ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL; + } + goto error; + } + } + + kernel_wait_quiescent(kernel_tracer_fd); + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_DISABLE_EVENT: + { + struct ltt_kernel_channel *chan; + struct ltt_kernel_event *ev; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } + + ev = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, chan); + if (ev != NULL) { + DBG("Disabling kernel event %s for channel %s.", + cmd_ctx->lsm->u.disable.name, cmd_ctx->lsm->u.disable.channel_name); + ret = kernel_disable_event(ev); + if (ret < 0) { + ret = LTTCOMM_KERN_ENABLE_FAIL; + goto error; + } + } + + kernel_wait_quiescent(kernel_tracer_fd); + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_DISABLE_ALL_EVENT: + { + struct ltt_kernel_channel *chan; + struct ltt_kernel_event *ev; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + DBG("Disabling all enabled kernel events"); + + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } + + /* For each event in the kernel session */ + cds_list_for_each_entry(ev, &chan->events_list.head, list) { + DBG("Disabling kernel event %s for channel %s.", + ev->event->name, cmd_ctx->lsm->u.disable.channel_name); + ret = kernel_disable_event(ev); + if (ret < 0) { + continue; + } + } + + /* Quiescent wait after event disable */ + kernel_wait_quiescent(kernel_tracer_fd); + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_ENABLE_CHANNEL: + { + struct ltt_kernel_channel *chan; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } else if (chan->enabled == 0) { + ret = kernel_enable_channel(chan); + if (ret < 0) { + if (ret != EEXIST) { + ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL; + } + goto error; + } + } + + kernel_wait_quiescent(kernel_tracer_fd); + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_ENABLE_EVENT: + { + struct ltt_kernel_channel *chan; + struct ltt_kernel_event *ev; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } + + ev = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, chan); + if (ev == NULL) { + DBG("Creating kernel event %s for channel %s.", + cmd_ctx->lsm->u.enable.event.name, chan->channel->name); + ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, chan); + } else { + DBG("Enabling kernel event %s for channel %s.", + cmd_ctx->lsm->u.enable.event.name, chan->channel->name); + ret = kernel_enable_event(ev); + } + + if (ret < 0) { + ret = LTTCOMM_KERN_ENABLE_FAIL; + goto error; + } + + kernel_wait_quiescent(kernel_tracer_fd); + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_ENABLE_ALL_EVENT: + { + int pos, size; + char *event_list, *event, *ptr; + struct ltt_kernel_channel *chan; + struct ltt_kernel_event *ev; + struct lttng_event ev_attr; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + DBG("Enabling all kernel event"); + + chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name, + cmd_ctx->session->kernel_session); + if (chan == NULL) { + ret = LTTCOMM_KERN_CHAN_NOT_FOUND; + goto error; + } + + /* For each event in the kernel session */ + cds_list_for_each_entry(ev, &chan->events_list.head, list) { + DBG("Enabling kernel event %s for channel %s.", + ev->event->name, chan->channel->name); + ret = kernel_enable_event(ev); + if (ret < 0) { + continue; + } + } + + size = kernel_list_events(kernel_tracer_fd, &event_list); + if (size < 0) { + ret = LTTCOMM_KERN_LIST_FAIL; + goto error; + } + + ptr = event_list; + while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) { + ev = get_kernel_event_by_name(event, chan); + if (ev == NULL) { + strncpy(ev_attr.name, event, LTTNG_SYM_NAME_LEN); + /* Default event type for enable all */ + ev_attr.type = LTTNG_EVENT_TRACEPOINTS; + /* Enable each single tracepoint event */ + ret = kernel_create_event(&ev_attr, chan); + if (ret < 0) { + /* Ignore error here and continue */ + } + } + + /* Move pointer to the next line */ + ptr += pos + 1; + free(event); + } + + free(event_list); + + /* Quiescent wait after event enable */ + kernel_wait_quiescent(kernel_tracer_fd); + ret = LTTCOMM_OK; + break; + } + case LTTNG_KERNEL_LIST_EVENTS: + { + char *event_list; + ssize_t size = 0; + + DBG("Listing kernel events"); + + size = kernel_list_events(kernel_tracer_fd, &event_list); + if (size < 0) { + ret = LTTCOMM_KERN_LIST_FAIL; + goto error; + } + + /* + * 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, size); + if (ret < 0) { + goto setup_error; + } + + /* Copy event list into message payload */ + memcpy(cmd_ctx->llm->payload, event_list, size); + + free(event_list); + + ret = LTTCOMM_OK; + break; + } + case LTTNG_START_TRACE: + { + struct ltt_kernel_channel *chan; + + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + /* Kernel tracing */ + if (cmd_ctx->session->kernel_session != NULL) { + if (cmd_ctx->session->kernel_session->metadata == NULL) { + DBG("Open kernel metadata"); + ret = kernel_open_metadata(cmd_ctx->session->kernel_session, + cmd_ctx->session->path); + if (ret < 0) { + ret = LTTCOMM_KERN_META_FAIL; + goto error; + } + } + + if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) { + DBG("Opening kernel metadata stream"); + if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) { + ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session); + if (ret < 0) { + ERR("Kernel create metadata stream failed"); + ret = LTTCOMM_KERN_STREAM_FAIL; + goto error; + } + } + } + + /* For each channel */ + cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) { + if (chan->stream_count == 0) { + ret = kernel_open_channel_stream(chan); + if (ret < 0) { + ERR("Kernel create channel stream failed"); + ret = LTTCOMM_KERN_STREAM_FAIL; + goto error; + } + /* Update the stream global counter */ + cmd_ctx->session->kernel_session->stream_count_global += ret; + } + } + + DBG("Start kernel tracing"); + ret = kernel_start_session(cmd_ctx->session->kernel_session); + if (ret < 0) { + ERR("Kernel start session failed"); + ret = LTTCOMM_KERN_START_FAIL; + goto error; + } + + ret = start_kernel_trace(cmd_ctx->session->kernel_session); + if (ret < 0) { + ret = LTTCOMM_KERN_START_FAIL; + goto error; + } + + /* Quiescent wait after starting trace */ + kernel_wait_quiescent(kernel_tracer_fd); + } + + /* TODO: Start all UST traces */ + + ret = LTTCOMM_OK; + break; + } + case LTTNG_STOP_TRACE: + { + struct ltt_kernel_channel *chan; + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + /* Kernel tracer */ + if (cmd_ctx->session->kernel_session != NULL) { + DBG("Stop kernel tracing"); + + ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd); + if (ret < 0) { + ERR("Kernel metadata flush failed"); + } + + cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) { + ret = kernel_flush_buffer(chan); + if (ret < 0) { + ERR("Kernel flush buffer error"); + } + } + + ret = kernel_stop_session(cmd_ctx->session->kernel_session); + if (ret < 0) { + ERR("Kernel stop session failed"); + ret = LTTCOMM_KERN_STOP_FAIL; + goto error; + } + + /* Quiescent wait after stopping trace */ + kernel_wait_quiescent(kernel_tracer_fd); + } + + /* TODO : User-space tracer */ + + ret = LTTCOMM_OK; + break; + } + case LTTNG_CREATE_SESSION: + { + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + ret = create_session(cmd_ctx->lsm->session_name, cmd_ctx->lsm->path); + if (ret < 0) { + if (ret == -EEXIST) { + ret = LTTCOMM_EXIST_SESS; + } else { + ret = LTTCOMM_FATAL; + } + goto error; + } + + ret = LTTCOMM_OK; + break; + } + case LTTNG_DESTROY_SESSION: + { + /* Setup lttng message with no payload */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + /* Clean kernel session teardown */ + teardown_kernel_session(cmd_ctx->session); + + ret = destroy_session(cmd_ctx->lsm->session_name); + if (ret < 0) { + ret = LTTCOMM_FATAL; + goto error; + } + + ret = LTTCOMM_OK; + break; + } + /* + case LTTNG_LIST_TRACES: + { + unsigned int trace_count; + + trace_count = get_trace_count_per_session(cmd_ctx->session); + if (trace_count == 0) { + ret = LTTCOMM_NO_TRACE; + goto error; + } + + ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count); + if (ret < 0) { + goto setup_error; + } + + get_traces_per_session(cmd_ctx->session, + (struct lttng_trace *)(cmd_ctx->llm->payload)); + + ret = LTTCOMM_OK; + break; + } + */ + /* + case UST_CREATE_TRACE: + { + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + ret = ust_create_trace(cmd_ctx); + if (ret < 0) { + goto error; + } + break; + } + */ + case LTTNG_LIST_TRACEABLE_APPS: + { + unsigned int app_count; + + app_count = get_app_count(); + DBG("Traceable application count : %d", app_count); + if (app_count == 0) { + ret = LTTCOMM_NO_APPS; + goto error; + } + + ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count); + if (ret < 0) { + goto setup_error; + } + + get_app_list_pids((pid_t *)(cmd_ctx->llm->payload)); + + ret = LTTCOMM_OK; + break; + } + /* + case UST_START_TRACE: + { + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } + + ret = ust_start_trace(cmd_ctx); + if (ret < 0) { + goto setup_error; + } + break; + } + case UST_STOP_TRACE: + { + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } - /* Protected by a mutex here because the threads manage_client - * and manage_apps can access this list. - */ - pthread_mutex_lock(<t_traceable_app_list_mutex); - cds_list_for_each_entry(iter, <t_traceable_app_list.head, list) { - pids[i] = iter->pid; - i++; + ret = ust_stop_trace(cmd_ctx); + if (ret < 0) { + goto setup_error; + } + break; } - pthread_mutex_unlock(<t_traceable_app_list_mutex); -} + */ + case LTTNG_LIST_SESSIONS: + { + unsigned int session_count; -/* - * copy_common_data - * - * Copy common data between lttcomm_lttng_msg and lttcomm_session_msg - */ -static void copy_common_data(struct lttcomm_lttng_msg *llm, struct lttcomm_session_msg *lsm) -{ - llm->cmd_type = lsm->cmd_type; - llm->pid = lsm->pid; + session_count = get_session_count(); + if (session_count == 0) { + ret = LTTCOMM_NO_SESSION; + goto error; + } - /* Manage uuid */ - if (!uuid_is_null(lsm->session_id)) { - uuid_copy(llm->session_id, lsm->session_id); - } + ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * session_count); + if (ret < 0) { + goto setup_error; + } - strncpy(llm->trace_name, lsm->trace_name, strlen(llm->trace_name)); - llm->trace_name[strlen(llm->trace_name) - 1] = '\0'; -} + get_lttng_session((struct lttng_session *)(cmd_ctx->llm->payload)); -/* - * setup_data_buffer - * - * Setup the outgoing data buffer for the response - * data allocating the right amount of memory. - * - * Return total size of the buffer pointed by buf. - */ -static int setup_data_buffer(char **buf, size_t s_data, struct lttcomm_lttng_msg *llm) -{ - int ret = 0; - size_t buf_size; + ret = LTTCOMM_OK; + break; + } + default: + /* Undefined command */ + ret = setup_lttng_msg(cmd_ctx, 0); + if (ret < 0) { + goto setup_error; + } - buf_size = sizeof(struct lttcomm_lttng_msg) + s_data; - *buf = malloc(buf_size); - if (*buf == NULL) { - perror("malloc"); - ret = -1; - goto error; + ret = LTTCOMM_UND; + break; } - /* Setup lttcomm_lttng_msg data and copy - * it to the newly allocated buffer. - */ - llm->size_payload = s_data; - memcpy(*buf, llm, sizeof(struct lttcomm_lttng_msg)); + /* Set return code */ + cmd_ctx->llm->ret_code = ret; - return buf_size; + return ret; error: + if (cmd_ctx->llm == NULL) { + DBG("Missing llm structure. Allocating one."); + if (setup_lttng_msg(cmd_ctx, 0) < 0) { + goto setup_error; + } + } + /* Notify client of error */ + cmd_ctx->llm->ret_code = ret; + +setup_error: return ret; } /* - * process_client_msg - * - * This takes the lttcomm_session_msg struct and process the command requested - * by the client. It then creates response(s) and send it back to the - * given socket (sock). + * thread_manage_clients * - * Return any error encountered or 0 for success. + * This thread manage all clients request using the unix + * client socket for communication. */ -static int process_client_msg(int sock, struct lttcomm_session_msg *lsm) +static void *thread_manage_clients(void *data) { - int ret; - int buf_size; - size_t header_size; - char *send_buf = NULL; - struct lttcomm_lttng_msg llm; + int sock, ret; + struct command_ctx *cmd_ctx; - /* Copy common data to identify the response - * on the lttng client side. - */ - copy_common_data(&llm, lsm); + DBG("[thread] Manage client started"); - /* Check command that needs a session */ - if (lsm->cmd_type != LTTNG_CREATE_SESSION && - lsm->cmd_type != LTTNG_LIST_SESSIONS && - lsm->cmd_type != UST_LIST_APPS) - { - current_session = find_session_by_uuid(lsm->session_id); - if (current_session == NULL) { - ret = LTTCOMM_SELECT_SESS; - goto end; - } + ret = lttcomm_listen_unix_sock(client_sock); + if (ret < 0) { + goto error; } - /* Default return code. - * In our world, everything is OK... right? ;) + /* Notify parent pid that we are ready + * to accept command for client side. */ - llm.ret_code = LTTCOMM_OK; - - header_size = sizeof(struct lttcomm_lttng_msg); - - /* Process by command type */ - switch (lsm->cmd_type) { - case LTTNG_CREATE_SESSION: - { - ret = create_session(lsm->session_name, &llm.session_id); - if (ret < 0) { - if (ret == -1) { - ret = LTTCOMM_EXIST_SESS; - } else { - ret = LTTCOMM_FATAL; - } - goto end; - } - - buf_size = setup_data_buffer(&send_buf, 0, &llm); - if (buf_size < 0) { - ret = LTTCOMM_FATAL; - goto end; - } - - break; - } - case LTTNG_DESTROY_SESSION: - { - ret = destroy_session(&lsm->session_id); - if (ret < 0) { - ret = LTTCOMM_NO_SESS; - } else { - ret = LTTCOMM_OK; - } - - /* No auxiliary data so only send the llm struct. */ - goto end; - } - case UST_CREATE_TRACE: - { - ret = ust_create_trace(lsm->pid); - if (ret < 0) { - ret = LTTCOMM_CREATE_FAIL; - goto end; - } + if (opt_sig_parent) { + kill(ppid, SIGCHLD); + } - /* No auxiliary data so only send the llm struct. */ - goto end; + while (1) { + /* Blocking call, waiting for transmission */ + DBG("Accepting client command ..."); + sock = lttcomm_accept_unix_sock(client_sock); + if (sock < 0) { + goto error; } - case UST_LIST_APPS: - { - /* Stop right now if no apps */ - if (traceable_app_count == 0) { - ret = LTTCOMM_NO_APPS; - goto end; - } - /* Setup data buffer and details for transmission */ - buf_size = setup_data_buffer(&send_buf, - sizeof(pid_t) * traceable_app_count, &llm); - if (buf_size < 0) { - ret = LTTCOMM_FATAL; - goto end; - } + /* Allocate context command to process the client request */ + cmd_ctx = malloc(sizeof(struct command_ctx)); - get_list_apps((pid_t *)(send_buf + header_size)); + /* Allocate data buffer for reception */ + cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg)); + cmd_ctx->llm = NULL; + cmd_ctx->session = NULL; - break; + /* + * Data is received from the lttng client. The struct + * lttcomm_session_msg (lsm) contains the command and data request of + * the client. + */ + DBG("Receiving data from client ..."); + ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg)); + if (ret <= 0) { + continue; } - case LTTNG_LIST_SESSIONS: - { - unsigned int session_count = get_session_count(); - /* Stop right now if no session */ - if (session_count == 0) { - ret = LTTCOMM_NO_SESS; - goto end; - } - - /* Setup data buffer and details for transmission */ - buf_size = setup_data_buffer(&send_buf, - (sizeof(struct lttng_session) * session_count), &llm); - if (buf_size < 0) { - ret = LTTCOMM_FATAL; - goto end; - } - get_lttng_session((struct lttng_session *)(send_buf + header_size)); + // TODO: Validate cmd_ctx including sanity check for security purpose. - break; + /* + * This function dispatch the work to the kernel or userspace tracer + * libs and fill the lttcomm_lttng_msg data structure of all the needed + * informations for the client. The command context struct contains + * everything this function may needs. + */ + ret = process_client_msg(cmd_ctx); + if (ret < 0) { + /* TODO: Inform client somehow of the fatal error. At this point, + * ret < 0 means that a malloc failed (ENOMEM). */ + /* Error detected but still accept command */ + clean_command_ctx(cmd_ctx); + continue; } - default: - { - /* Undefined command */ - ret = LTTCOMM_UND; - goto end; + + DBG("Sending response (size: %d, retcode: %d)", + cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code); + ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size); + if (ret < 0) { + ERR("Failed to send data back to client"); } - } - ret = send_unix_sock(sock, send_buf, buf_size); + clean_command_ctx(cmd_ctx); - if (send_buf != NULL) { - free(send_buf); + /* End of transmission */ + close(sock); } - return ret; - -end: - /* Notify client of error */ - llm.ret_code = ret; - llm.size_payload = 0; - send_unix_sock(sock, (void*) &llm, sizeof(llm)); - - return ret; +error: + return NULL; } + /* * usage function on stderr */ static void usage(void) { fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname); - fprintf(stderr, " -h, --help Display this usage.\n"); - fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n"); - fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket.\n"); - fprintf(stderr, " -d, --daemonize Start as a daemon.\n"); - fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n"); - fprintf(stderr, " -V, --version Show version number.\n"); - fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n"); - fprintf(stderr, " -q, --quiet No output at all.\n"); + fprintf(stderr, " -h, --help Display this usage.\n"); + fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n"); + fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n"); + fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n"); + fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n"); + fprintf(stderr, " -d, --daemonize Start as a daemon.\n"); + fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n"); + fprintf(stderr, " -V, --version Show version number.\n"); + fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n"); + fprintf(stderr, " -q, --quiet No output at all.\n"); + fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n"); } /* @@ -645,18 +1736,21 @@ static int parse_args(int argc, char **argv) static struct option long_options[] = { { "client-sock", 1, 0, 'c' }, { "apps-sock", 1, 0, 'a' }, + { "kconsumerd-cmd-sock", 1, 0, 0 }, + { "kconsumerd-err-sock", 1, 0, 0 }, { "daemonize", 0, 0, 'd' }, { "sig-parent", 0, 0, 'S' }, { "help", 0, 0, 'h' }, { "group", 1, 0, 'g' }, { "version", 0, 0, 'V' }, { "quiet", 0, 0, 'q' }, + { "verbose", 0, 0, 'v' }, { NULL, 0, 0, 0 } }; while (1) { int option_index = 0; - c = getopt_long(argc, argv, "dhqVS" "a:c:g:s:", long_options, &option_index); + c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index); if (c == -1) { break; } @@ -689,9 +1783,18 @@ static int parse_args(int argc, char **argv) case 'S': opt_sig_parent = 1; break; + case 'E': + snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg); + break; + case 'C': + snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg); + break; case 'q': opt_quiet = 1; break; + case 'v': + opt_verbose = 1; + break; default: /* Unknown option or other error. * Error is printed by getopt, just return */ @@ -706,8 +1809,8 @@ static int parse_args(int argc, char **argv) * init_daemon_socket * * Creates the two needed socket by the daemon. - * apps_socket - The communication socket for all UST apps. - * client_socket - The communication of the cli tool (lttng). + * apps_sock - The communication socket for all UST apps. + * client_sock - The communication of the cli tool (lttng). */ static int init_daemon_socket() { @@ -717,8 +1820,9 @@ static int init_daemon_socket() old_umask = umask(0); /* Create client tool unix socket */ - client_socket = lttcomm_create_unix_sock(client_unix_sock_path); - if (client_socket < 0) { + client_sock = lttcomm_create_unix_sock(client_unix_sock_path); + if (client_sock < 0) { + ERR("Create unix sock failed: %s", client_unix_sock_path); ret = -1; goto end; } @@ -726,20 +1830,23 @@ static int init_daemon_socket() /* File permission MUST be 660 */ ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); if (ret < 0) { + ERR("Set file permissions failed: %s", client_unix_sock_path); perror("chmod"); goto end; } /* Create the application unix socket */ - apps_socket = lttcomm_create_unix_sock(apps_unix_sock_path); - if (apps_socket < 0) { + apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path); + if (apps_sock < 0) { + ERR("Create unix sock failed: %s", apps_unix_sock_path); ret = -1; goto end; } - /* File permission MUST be 660 */ + /* File permission MUST be 666 */ ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); if (ret < 0) { + ERR("Set file permissions failed: %s", apps_unix_sock_path); perror("chmod"); goto end; } @@ -753,7 +1860,7 @@ end: * check_existing_daemon * * Check if the global socket is available. - * If yes, error is returned. + * If yes, error is returned. */ static int check_existing_daemon() { @@ -768,30 +1875,14 @@ static int check_existing_daemon() } /* - * get_home_dir + * set_permissions * - * Return pointer to home directory path using - * the env variable HOME. - * - * Default : /tmp - */ -static const char *get_home_dir(void) -{ - const char *home_path; - - if ((home_path = (const char *) getenv("HOME")) == NULL) { - home_path = default_home_dir; - } - - return home_path; -} - -/* - * set_socket_perms + * Set the tracing group gid onto the client socket. * - * Set the tracing group gid onto the client socket. + * Race window between mkdir and chown is OK because we are going from + * more permissive (root.root) to les permissive (root.tracing). */ -static int set_socket_perms(void) +static int set_permissions(void) { int ret; struct group *grp; @@ -802,24 +1893,144 @@ static int set_socket_perms(void) (grp = getgrnam(default_tracing_group)); if (grp == NULL) { - ERR("Missing tracing group. Aborting execution.\n"); - ret = -1; + if (is_root) { + WARN("No tracing group detected"); + ret = 0; + } else { + ERR("Missing tracing group. Aborting execution."); + ret = -1; + } goto end; } + /* Set lttng run dir */ + ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid); + if (ret < 0) { + ERR("Unable to set group on " LTTNG_RUNDIR); + perror("chown"); + } + + /* lttng client socket path */ ret = chown(client_unix_sock_path, 0, grp->gr_gid); if (ret < 0) { + ERR("Unable to set group on %s", client_unix_sock_path); + perror("chown"); + } + + /* kconsumerd error socket path */ + ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid); + if (ret < 0) { + ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path); perror("chown"); } + DBG("All permissions are set"); + end: return ret; } /* - * set_signal_handler + * create_lttng_rundir + * + * Create the lttng run directory needed for all + * global sockets and pipe. + */ +static int create_lttng_rundir(void) +{ + int ret; + + ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG ); + if (ret < 0) { + if (errno != EEXIST) { + ERR("Unable to create " LTTNG_RUNDIR); + goto error; + } else { + ret = 0; + } + } + +error: + return ret; +} + +/* + * set_kconsumerd_sockets + * + * Setup sockets and directory needed by the kconsumerd + * communication with the session daemon. + */ +static int set_kconsumerd_sockets(void) +{ + int ret; + + if (strlen(kconsumerd_err_unix_sock_path) == 0) { + snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH); + } + + if (strlen(kconsumerd_cmd_unix_sock_path) == 0) { + snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH); + } + + ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG); + if (ret < 0) { + if (errno != EEXIST) { + ERR("Failed to create " KCONSUMERD_PATH); + goto error; + } + ret = 0; + } + + /* Create the kconsumerd error unix socket */ + kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path); + if (kconsumerd_err_sock < 0) { + ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path); + ret = -1; + goto error; + } + + /* File permission MUST be 660 */ + ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); + if (ret < 0) { + ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path); + perror("chmod"); + goto error; + } + +error: + return ret; +} + +/* + * sighandler + * + * Signal handler for the daemon + */ +static void sighandler(int sig) +{ + switch (sig) { + case SIGPIPE: + DBG("SIGPIPE catched"); + return; + case SIGINT: + DBG("SIGINT catched"); + cleanup(); + break; + case SIGTERM: + DBG("SIGTERM catched"); + cleanup(); + break; + default: + break; + } + + exit(EXIT_SUCCESS); +} + +/* + * set_signal_handler * - * Setup signal handler for : + * Setup signal handler for : * SIGINT, SIGTERM, SIGPIPE */ static int set_signal_handler(void) @@ -851,44 +2062,29 @@ static int set_signal_handler(void) return ret; } - return ret; -} - -/** - * sighandler - * - * Signal handler for the daemon - */ -static void sighandler(int sig) -{ - switch (sig) { - case SIGPIPE: - return; - case SIGINT: - case SIGTERM: - cleanup(); - break; - default: - break; - } + DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT"); - exit(EXIT_SUCCESS); + return ret; } /* - * cleanup + * set_ulimit * - * Cleanup the daemon on exit + * Set open files limit to unlimited. This daemon can open a large number of + * file descriptors in order to consumer multiple kernel traces. */ -static void cleanup() +static void set_ulimit(void) { - /* */ - MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0); - MSG("%c[%d;%dmMatthew, BEET driven development works!%c[%dm",27,1,33,27,0); - /* */ + int ret; + struct rlimit lim; - unlink(client_unix_sock_path); - unlink(apps_unix_sock_path); + lim.rlim_cur = 65535; + lim.rlim_max = 65535; + + ret = setrlimit(RLIMIT_NOFILE, &lim); + if (ret < 0) { + perror("failed to set open files limit"); + } } /* @@ -896,10 +2092,9 @@ static void cleanup() */ int main(int argc, char **argv) { - int i; int ret = 0; void *status; - pthread_t threads[2]; + const char *home_path; /* Parse arguments */ progname = argv[0]; @@ -919,52 +2114,77 @@ int main(int argc, char **argv) /* Check if daemon is UID = 0 */ is_root = !getuid(); - /* Set all sockets path */ if (is_root) { + ret = create_lttng_rundir(); + if (ret < 0) { + goto error; + } + if (strlen(apps_unix_sock_path) == 0) { - (snprintf(apps_unix_sock_path, PATH_MAX, - DEFAULT_GLOBAL_APPS_UNIX_SOCK)); + snprintf(apps_unix_sock_path, PATH_MAX, + DEFAULT_GLOBAL_APPS_UNIX_SOCK); } if (strlen(client_unix_sock_path) == 0) { - (snprintf(client_unix_sock_path, PATH_MAX, - DEFAULT_GLOBAL_CLIENT_UNIX_SOCK)); + snprintf(client_unix_sock_path, PATH_MAX, + DEFAULT_GLOBAL_CLIENT_UNIX_SOCK); + } + + ret = set_kconsumerd_sockets(); + if (ret < 0) { + goto error; } + + /* Setup kernel tracer */ + init_kernel_tracer(); + + /* Set ulimit for open files */ + set_ulimit(); } else { + home_path = get_home_dir(); + if (home_path == NULL) { + ERR("Can't get HOME directory for sockets creation.\n \ + Please specify --socket PATH."); + goto error; + } + if (strlen(apps_unix_sock_path) == 0) { - (snprintf(apps_unix_sock_path, PATH_MAX, - DEFAULT_HOME_APPS_UNIX_SOCK, get_home_dir())); + snprintf(apps_unix_sock_path, PATH_MAX, + DEFAULT_HOME_APPS_UNIX_SOCK, home_path); } /* Set the cli tool unix socket path */ if (strlen(client_unix_sock_path) == 0) { - (snprintf(client_unix_sock_path, PATH_MAX, - DEFAULT_HOME_CLIENT_UNIX_SOCK, get_home_dir())); + snprintf(client_unix_sock_path, PATH_MAX, + DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path); } } + DBG("Client socket path %s", client_unix_sock_path); + DBG("Application socket path %s", apps_unix_sock_path); + /* See if daemon already exist. If any of the two * socket needed by the daemon are present, this test fails */ if ((ret = check_existing_daemon()) == 0) { ERR("Already running daemon.\n"); /* We do not goto error because we must not - * cleanup() because a daemon is already working. + * cleanup() because a daemon is already running. */ - return EXIT_FAILURE; + exit(EXIT_FAILURE); } if (set_signal_handler() < 0) { goto error; } - /* Setup the two needed unix socket */ + /* Setup the needed unix socket */ if (init_daemon_socket() < 0) { goto error; } /* Set credentials to socket */ - if (is_root && (set_socket_perms() < 0)) { + if (is_root && (set_permissions() < 0)) { goto error; } @@ -975,33 +2195,30 @@ int main(int argc, char **argv) while (1) { /* Create thread to manage the client socket */ - ret = pthread_create(&threads[0], NULL, thread_manage_clients, (void *) NULL); + ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL); if (ret != 0) { perror("pthread_create"); goto error; } /* Create thread to manage application socket */ - ret = pthread_create(&threads[1], NULL, thread_manage_apps, (void *) NULL); + ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL); if (ret != 0) { perror("pthread_create"); goto error; } - for (i = 0; i < 2; i++) { - ret = pthread_join(threads[i], &status); - if (ret != 0) { - perror("pthread_join"); - goto error; - } + ret = pthread_join(client_thread, &status); + if (ret != 0) { + perror("pthread_join"); + goto error; } } cleanup(); - return 0; + exit(EXIT_SUCCESS); error: cleanup(); - - return EXIT_FAILURE; + exit(EXIT_FAILURE); }