[lttng-tools.git] / ltt-sessiond / main.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *
 * This program is free software; you can redistribute it and/or
 * 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.
 */

#define _GNU_SOURCE
#include <fcntl.h>
#include <getopt.h>
#include <grp.h>
#include <limits.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <urcu/list.h>          /* URCU list library (-lurcu) */
#include <ust/ustctl.h>         /* UST control lib (-lust) */
#include <lttng/lttng.h>

#include "liblttsessiondcomm.h"
#include "ltt-sessiond.h"
#include "lttngerr.h"
#include "session.h"
#include "trace.h"
#include "traceable-app.h"

/* Const values */
const char default_home_dir[] = DEFAULT_HOME_DIR;
const char default_tracing_group[] = 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 check_existing_daemon(void);
static int connect_app(pid_t pid);
static int init_daemon_socket(void);
static int notify_apps(const char* name);
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 set_signal_handler(void);
static int set_permissions(void);
static int setup_data_buffer(char **buf, size_t size, struct lttcomm_lttng_header *llh);
static int create_lttng_rundir(void);
static int set_kconsumerd_sockets(void);
static void cleanup(void);
static void copy_common_data(struct lttcomm_lttng_header *llh, struct lttcomm_session_msg *lsm);
static void sighandler(int sig);

static void *thread_manage_clients(void *data);
static void *thread_manage_apps(void *data);
static void *thread_manage_kconsumerd(void *data);

/* Variables */
int opt_verbose;
int opt_quiet;
const char *progname;
const char *opt_tracing_group;
static int opt_sig_parent;
static int opt_daemon;
static int is_root;                     /* Set to 1 if the daemon is running as root */
static pid_t ppid;

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_sock;
static int apps_sock;
static int kconsumerd_err_sock;

static struct ltt_session *current_session;

/*
 *  thread_manage_kconsumerd
 *
 *  This thread manage the kconsumerd error sent
 *  back to the session daemon.
 */
static void *thread_manage_kconsumerd(void *data)
{
        int sock, ret;

        DBG("[thread] Manage kconsumerd started");

        ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
        if (ret < 0) {
                goto error;
        }

        sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
        if (sock < 0) {
                goto error;
        }

        while (1) {
                //ret = lttcomm_recv_unix_sock(sock, &lsm, sizeof(lsm));
                if (ret <= 0) {
                        /* TODO: Consumerd died? */
                        continue;
                }
        }

error:
        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 */
        struct {
                int reg;        /* 1:register, 0:unregister */
                pid_t pid;
                uid_t uid;
        } reg_msg;

        DBG("[thread] Manage apps started");

        /* Notify all applications to register */
        notify_apps(default_global_apps_pipe);

        ret = lttcomm_listen_unix_sock(apps_sock);
        if (ret < 0) {
                goto error;
        }

        while (1) {
                /* 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, &reg_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 NULL;
}

/*
 *      thread_manage_clients
 *
 *      This thread manage all clients request using the unix
 *      client socket for communication.
 */
static void *thread_manage_clients(void *data)
{
        int sock, ret;
        struct lttcomm_session_msg lsm;

        DBG("[thread] Manage client started");

        ret = lttcomm_listen_unix_sock(client_sock);
        if (ret < 0) {
                goto error;
        }

        /* Notify parent pid that we are ready
         * to accept command for client side.
         */
        if (opt_sig_parent) {
                kill(ppid, SIGCHLD);
        }

        while (1) {
                /* Blocking call, waiting for transmission */
                sock = lttcomm_accept_unix_sock(client_sock);
                if (sock < 0) {
                        goto error;
                }

                /*
                 * 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;
                }

                /* 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_header 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;
                }
        }

error:
        return NULL;
}

/*
 *  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 lttcomm_send_unix_sock(sock, buf, len);
}

/*
 *      connect_app
 *
 *      Return a socket connected to the libust communication socket
 *      of the application identified by the pid.
 *
 *      If the pid is not found in the traceable list,
 *      return -1 to indicate error.
 */
static int connect_app(pid_t pid)
{
        int sock;
        struct ltt_traceable_app *lta;

        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(lta->pid);
        if (sock < 0) {
                ERR("Fail connecting to the PID %d\n", pid);
        }

        return sock;
}

/*
 *      notify_apps
 *
 *  Notify apps by writing 42 to a named pipe using name.
 *      Every applications waiting for a ltt-sessiond will be notified
 *      and re-register automatically to the session daemon.
 *
 *      Return open or write error value.
 */
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) {
                goto error;
        }

        /* Notify by writing on the pipe */
        ret = write(fd, "42", 2);
        if (ret < 0) {
                perror("write");
        }

error:
        return ret;
}

/*
 *  ust_create_trace
 *
 *  Create an userspace trace using pid.
 *  This trace is then appended to the current session
 *  ust trace list.
 */
static int ust_create_trace(pid_t pid)
{
        int sock, ret;
        struct ltt_ust_trace *trace;

        DBG("Creating trace for pid %d", pid);

        trace = malloc(sizeof(struct ltt_ust_trace));
        if (trace == NULL) {
                perror("malloc");
                ret = -1;
                goto error;
        }

        /* Init */
        trace->pid = pid;
        trace->shmid = 0;
        /* NOTE: to be removed. Trace name will no longer be
         * required for LTTng userspace tracer. For now, we set it
         * to 'auto' for API compliance.
         */
        snprintf(trace->name, 5, "auto");

        /* Connect to app using ustctl API */
        sock = connect_app(pid);
        if (sock < 0) {
                ret = LTTCOMM_NO_TRACEABLE;
                goto error;
        }

        ret = ustctl_create_trace(sock, trace->name);
        if (ret < 0) {
                ret = LTTCOMM_CREATE_FAIL;
                goto error;
        }

        /* Check if current session is valid */
        if (current_session) {
                cds_list_add(&trace->list, &current_session->ust_traces);
                current_session->ust_trace_count++;
        }

error:
        return ret;
}

/*
 *  ust_start_trace
 *
 *  Start a trace. This trace, identified by the pid, must be
 *  in the current session ust_traces list.
 */
static int ust_start_trace(pid_t pid)
{
        int sock, ret;
        struct ltt_ust_trace *trace;

        DBG("Starting trace for pid %d", pid);

        trace = find_session_ust_trace_by_pid(current_session, pid);
        if (trace == NULL) {
                ret = LTTCOMM_NO_TRACE;
                goto error;
        }

        /* Connect to app using ustctl API */
        sock = connect_app(pid);
        if (sock < 0) {
                ret = LTTCOMM_NO_TRACEABLE;
                goto error;
        }

        ret = ustctl_start_trace(sock, "auto");
        if (ret < 0) {
                ret = LTTCOMM_START_FAIL;
                goto error;
        }

error:
        return ret;
}

/*
 *  ust_stop_trace
 *
 *  Stop a trace. This trace, identified by the pid, must be
 *  in the current session ust_traces list.
 */
static int ust_stop_trace(pid_t pid)
{
        int sock, ret;
        struct ltt_ust_trace *trace;

        DBG("Stopping trace for pid %d", pid);

        trace = find_session_ust_trace_by_pid(current_session, pid);
        if (trace == NULL) {
                ret = LTTCOMM_NO_TRACE;
                goto error;
        }

        /* Connect to app using ustctl API */
        sock = connect_app(pid);
        if (sock < 0) {
                ret = LTTCOMM_NO_TRACEABLE;
                goto error;
        }

        ret = ustctl_stop_trace(sock, trace->name);
        if (ret < 0) {
                ret = LTTCOMM_STOP_FAIL;
                goto error;
        }

error:
        return ret;
}

/*
 *  copy_common_data
 *
 *  Copy common data between lttcomm_lttng_header and lttcomm_session_msg
 */
static void copy_common_data(struct lttcomm_lttng_header *llh, struct lttcomm_session_msg *lsm)
{
        llh->cmd_type = lsm->cmd_type;
        llh->pid = lsm->pid;

        /* Manage uuid */
        if (!uuid_is_null(lsm->session_id)) {
                uuid_copy(llh->session_id, lsm->session_id);
        }

        strncpy(llh->trace_name, lsm->trace_name, strlen(llh->trace_name));
        llh->trace_name[strlen(llh->trace_name) - 1] = '\0';
}

/*
 *  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_header *llh)
{
        int ret = 0;
        size_t buf_size;

        buf_size = sizeof(struct lttcomm_lttng_header) + s_data;
        *buf = malloc(buf_size);
        if (*buf == NULL) {
                perror("malloc");
                ret = -1;
                goto error;
        }

        /* Setup lttcomm_lttng_header data and copy
         * it to the newly allocated buffer.
         */
        llh->payload_size = s_data;
        memcpy(*buf, llh, sizeof(struct lttcomm_lttng_header));

        return buf_size;

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).
 *
 *      Return any error encountered or 0 for success.
 */
static int process_client_msg(int sock, struct lttcomm_session_msg *lsm)
{
        int ret;
        int buf_size;
        size_t header_size;
        char *send_buf = NULL;
        struct lttcomm_lttng_header llh;

        DBG("Processing client message");

        /* Copy common data to identify the response
         * on the lttng client side.
         */
        copy_common_data(&llh, lsm);

        /* 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;
                }
        }

        /* Default return code.
         * In our world, everything is OK... right? ;)
         */
        llh.ret_code = LTTCOMM_OK;

        header_size = sizeof(struct lttcomm_lttng_header);

        /* Process by command type */
        switch (lsm->cmd_type) {
                case LTTNG_CREATE_SESSION:
                {
                        ret = create_session(lsm->session_name, &llh.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, &llh);
                        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 llh struct. */
                        goto end;
                }
                case LTTNG_LIST_TRACES:
                {
                        unsigned int trace_count = get_trace_count_per_session(current_session);

                        if (trace_count == 0) {
                                ret = LTTCOMM_NO_TRACE;
                                goto end;
                        }

                        buf_size = setup_data_buffer(&send_buf,
                                        sizeof(struct lttng_trace) * trace_count, &llh);
                        if (buf_size < 0) {
                                ret = LTTCOMM_FATAL;
                                goto end;
                        }

                        get_traces_per_session(current_session, (struct lttng_trace *)(send_buf + header_size));
                        break;
                }
                case UST_CREATE_TRACE:
                {
                        ret = ust_create_trace(lsm->pid);
                        if (ret < 0) {
                                /* If -1 is returned from ust_create_trace, malloc
                                 * failed so it's pretty much a fatal error.
                                 */
                                ret = LTTCOMM_FATAL;
                                goto end;
                        }

                        /* No auxiliary data so only send the llh struct. */
                        goto end;
                }
                case UST_LIST_APPS:
                {
                        unsigned int app_count = get_app_count();
                        /* Stop right now if no apps */
                        if (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) * app_count, &llh);
                        if (buf_size < 0) {
                                ret = LTTCOMM_FATAL;
                                goto end;
                        }

                        get_app_list_pids((pid_t *)(send_buf + header_size));

                        break;
                }
                case UST_START_TRACE:
                {
                        ret = ust_start_trace(lsm->pid);

                        /* No auxiliary data so only send the llh struct. */
                        goto end;
                }
                case UST_STOP_TRACE:
                {
                        ret = ust_stop_trace(lsm->pid);

                        /* No auxiliary data so only send the llh struct. */
                        goto end;
                }
                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), &llh);
                        if (buf_size < 0) {
                                ret = LTTCOMM_FATAL;
                                goto end;
                        }

                        get_lttng_session((struct lttng_session *)(send_buf + header_size));

                        break;
                }
                default:
                {
                        /* Undefined command */
                        ret = LTTCOMM_UND;
                        goto end;
                }
        }

        ret = send_unix_sock(sock, send_buf, buf_size);

        if (send_buf != NULL) {
                free(send_buf);
        }

        return ret;

end:
        DBG("Return code to client %d", ret);
        /* Notify client of error */
        llh.ret_code = ret;
        llh.payload_size = 0;
        send_unix_sock(sock, (void*) &llh, sizeof(llh));

        return ret;
}

/*
 * 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, "      --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");
}

/*
 * daemon argument parsing
 */
static int parse_args(int argc, char **argv)
{
        int c;

        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, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
                if (c == -1) {
                        break;
                }

                switch (c) {
                case 0:
                        fprintf(stderr, "option %s", long_options[option_index].name);
                        if (optarg) {
                                fprintf(stderr, " with arg %s\n", optarg);
                        }
                        break;
                case 'c':
                        snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
                        break;
                case 'a':
                        snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
                        break;
                case 'd':
                        opt_daemon = 1;
                        break;
                case 'g':
                        opt_tracing_group = strdup(optarg);
                        break;
                case 'h':
                        usage();
                        exit(EXIT_FAILURE);
                case 'V':
                        fprintf(stdout, "%s\n", VERSION);
                        exit(EXIT_SUCCESS);
                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 */
                        return -1;
                }
        }

        return 0;
}

/*
 *      init_daemon_socket
 *
 *      Creates the two needed socket by the daemon.
 *          apps_sock - The communication socket for all UST apps.
 *          client_sock - The communication of the cli tool (lttng).
 */
static int init_daemon_socket()
{
        int ret = 0;
        mode_t old_umask;

        old_umask = umask(0);

        /* Create client tool unix socket */
        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;
        }

        /* 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_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 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;
        }

end:
        umask(old_umask);
        return ret;
}

/*
 *      check_existing_daemon
 *
 *      Check if the global socket is available.
 *  If yes, error is returned.
 */
static int check_existing_daemon()
{
        int ret;

        ret = access(client_unix_sock_path, F_OK);
        if (ret == 0) {
                ret = access(apps_unix_sock_path, F_OK);
        }

        return ret;
}

/*
 *  get_home_dir
 *
 *  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_permissions
 *
 *      Set the tracing group gid onto the client socket.
 */
static int set_permissions(void)
{
        int ret;
        struct group *grp;

        /* Decide which group name to use */
        (opt_tracing_group != NULL) ?
                (grp = getgrnam(opt_tracing_group)) :
                (grp = getgrnam(default_tracing_group));

        if (grp == NULL) {
                ERR("Missing tracing group. Aborting execution.\n");
                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;
}

/*
 *  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) {
                ERR("Unable to create " LTTNG_RUNDIR);
                goto error;
        }

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) {
                ERR("Failed to create " KCONSUMERD_PATH);
                goto error;
        }

        /* 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;
}

/*
 *  set_signal_handler
 *
 *  Setup signal handler for :
 *              SIGINT, SIGTERM, SIGPIPE
 */
static int set_signal_handler(void)
{
        int ret = 0;
        struct sigaction sa;
        sigset_t sigset;

        if ((ret = sigemptyset(&sigset)) < 0) {
                perror("sigemptyset");
                return ret;
        }

        sa.sa_handler = sighandler;
        sa.sa_mask = sigset;
        sa.sa_flags = 0;
        if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
                perror("sigaction");
                return ret;
        }

        if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
                perror("sigaction");
                return ret;
        }

        if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
                perror("sigaction");
                return ret;
        }

        DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");

        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);
}

/*
 *  cleanup
 *
 *  Cleanup the daemon on exit
 */
static void cleanup()
{
        int ret;
        char *cmd;

        DBG("Cleaning up");

        /* <fun> */
        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);
        /* </fun> */

        unlink(client_unix_sock_path);
        unlink(apps_unix_sock_path);
        unlink(kconsumerd_err_unix_sock_path);

        ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
        if (ret < 0) {
                ERR("asprintf failed. Something is really wrong!");
        }

        /* Remove lttng run directory */
        ret = system(cmd);
        if (ret < 0) {
                ERR("Unable to clean " LTTNG_RUNDIR);
        }
}

/*
 * main
 */
int main(int argc, char **argv)
{
        int i;
        int ret = 0;
        void *status;
        pthread_t threads[2];

        /* Parse arguments */
        progname = argv[0];
        if ((ret = parse_args(argc, argv) < 0)) {
                goto error;
        }

        /* Daemonize */
        if (opt_daemon) {
                ret = daemon(0, 0);
                if (ret < 0) {
                        perror("daemon");
                        goto error;
                }
        }

        /* 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);
                }

                if (strlen(client_unix_sock_path) == 0) {
                        snprintf(client_unix_sock_path, PATH_MAX,
                                        DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
                }

                ret = set_kconsumerd_sockets();
                if (ret < 0) {
                        goto error;
                }
        } else {
                if (strlen(apps_unix_sock_path) == 0) {
                        snprintf(apps_unix_sock_path, PATH_MAX,
                                        DEFAULT_HOME_APPS_UNIX_SOCK, get_home_dir());
                }

                /* 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());
                }
        }

        /* 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 running.
                 */
                return EXIT_FAILURE;
        }

        if (set_signal_handler() < 0) {
                goto error;
        }

        /* Setup the needed unix socket */
        if (init_daemon_socket() < 0) {
                goto error;
        }

        /* Set credentials to socket */
        if (is_root && (set_permissions() < 0)) {
                goto error;
        }

        /* Get parent pid if -S, --sig-parent is specified. */
        if (opt_sig_parent) {
                ppid = getppid();
        }

        while (1) {
                /* Create thread to manage the client socket */
                ret = pthread_create(&threads[0], 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);
                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;
                        }
                }
        }

        cleanup();
        return 0;

error:
        cleanup();

        return EXIT_FAILURE;
}