Major changes for the daemon data transmission
[lttng-tools.git] / ltt-sessiond / ltt-sessiond.c
index c3b117da304458f48973e623227fe0662d6cae65..fb197d43bc60c37228526ba6b72a3b5ff5abc1e2 100644 (file)
 
 #include <urcu/list.h>         /* URCU list library (-lurcu) */
 #include <ust/ustctl.h>                /* UST control lib (-lust) */
+#include <lttng/liblttngctl.h>
 
 #include "liblttsessiondcomm.h"
 #include "ltt-sessiond.h"
+#include "lttngerr.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;
@@ -48,7 +51,6 @@ const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
 static int set_signal_handler(void);
 static int set_socket_perms(void);
 static void sighandler(int);
-static void daemonize(void);
 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);
@@ -58,6 +60,10 @@ 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);
 
+/* Command function */
+static void get_list_apps(void *buf);
+static void get_list_sessions(void *buf);
+
 static void *thread_manage_clients(void *);
 static void *thread_manage_apps(void *);
 
@@ -71,6 +77,8 @@ 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;
 
@@ -256,7 +264,7 @@ static int connect_app(pid_t pid)
 
        sock = ustctl_connect_pid(pid);
        if (sock < 0) {
-               fprintf(stderr, "Fail connecting to the PID %d\n", pid);
+               ERR("Fail connecting to the PID %d\n", pid);
        }
 
        return sock;
@@ -392,36 +400,47 @@ error:
 }
 
 /*
- *     ust_list_apps
+ *     get_list_apps
  *
  *  List traceable user-space application and fill an
  *  array of pids.
- *
- *  Return size of the array.
  */
-static size_t ust_list_apps(pid_t **pids)
+static void get_list_apps(void *buf)
 {
-       size_t size = 0;
+       size_t index = 0;
        struct ltt_traceable_app *iter = NULL;
-       pid_t *p;
-
-       if (traceable_app_count == 0) {
-               /* No dynamic allocation is done */
-               goto end;
-       }
-
-       p = malloc(sizeof(pid_t) * traceable_app_count);
+       pid_t *pids = (pid_t *) buf;
 
        /* TODO: Mutex needed to access this list */
        cds_list_for_each_entry(iter, &ltt_traceable_app_list.head, list) {
-               p[size] = iter->pid;
-               size++;
+               pids[index] = iter->pid;
+               index++;
        }
+}
 
-       *pids = p;
+/*
+ *  get_list_sessions
+ *
+ *  List sessions and fill the data buffer.
+ */
+static void get_list_sessions(void *buf)
+{
+       int i = 0;
+       struct ltt_session *iter = NULL;
+       struct lttng_session lsess;
+       struct lttng_session *data = (struct lttng_session *) buf;
 
-end:
-       return size;
+       /* Iterate over session list and append data after
+        * the control struct in the buffer.
+        */
+       cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
+               uuid_unparse(iter->uuid, lsess.uuid);
+               strncpy(lsess.name, iter->name, sizeof(lsess.name));
+               memcpy(data + (i * sizeof(struct lttng_session)), &lsess, sizeof(lsess));
+               i++;
+               /* Reset struct for next pass */
+               memset(&lsess, 0, sizeof(lsess));
+       }
 }
 
 /*
@@ -439,6 +458,42 @@ static void copy_common_data(struct lttcomm_lttng_msg *llm, struct lttcomm_sessi
        strncpy(llm->trace_name, lsm->trace_name, sizeof(llm->trace_name));
 }
 
+/*
+ *  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(void **buf, size_t s_data, struct lttcomm_lttng_msg *llm)
+{
+       int ret = 0;
+       void *new_buf;
+       size_t buf_size;
+
+       buf_size = sizeof(struct lttcomm_lttng_msg) + s_data;
+       new_buf = malloc(buf_size);
+       if (new_buf == NULL) {
+               perror("malloc");
+               ret = -1;
+               goto error;
+       }
+
+       /* Setup lttcomm_lttng_msg data and copy
+        * it to the newly allocated buffer.
+        */
+       llm->size_payload = s_data;
+       memcpy(new_buf, llm, sizeof(struct lttcomm_lttng_msg));
+
+       *buf = new_buf;
+
+       return buf_size;
+
+error:
+       return ret;
+}
+
 /*
  *     process_client_msg
  *
@@ -452,6 +507,8 @@ static int process_client_msg(int sock, struct lttcomm_session_msg *lsm)
 {
        int ret;
        struct lttcomm_lttng_msg llm;
+       void *send_buf = NULL;
+       int buf_size;
 
        /* Copy common data to identify the response
         * on the lttng client side.
@@ -467,24 +524,51 @@ static int process_client_msg(int sock, struct lttcomm_session_msg *lsm)
        switch (lsm->cmd_type) {
                case UST_LIST_APPS:
                {
-                       pid_t *pids;
-                       llm.num_pckt = ust_list_apps(&pids);
-                       if (llm.num_pckt == 0) {
+                       /* Stop right now if no apps */
+                       if (traceable_app_count == 0) {
                                ret = LTTCOMM_NO_APPS;
                                goto error;
                        }
 
-                       /* Send all packets */
-                       while (llm.num_pckt != 0) {
-                               llm.u.list_apps.pid = pids[traceable_app_count - llm.num_pckt];
-                               ret = send_unix_sock(sock, (void*) &llm, sizeof(llm));
-                               if (ret < 0) {
-                                       goto send_error;
-                               }
-                               llm.num_pckt--;
+                       /* 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 error;
+                       }
+
+                       get_list_apps(send_buf + sizeof(struct lttcomm_lttng_msg));
+
+                       ret = send_unix_sock(sock, send_buf, buf_size);
+                       if (ret < 0) {
+                               goto send_error;
+                       }
+
+                       break;
+               }
+               case LTTNG_LIST_SESSIONS:
+               {
+                       /* Stop right now if no session */
+                       if (session_count == 0) {
+                               ret = LTTCOMM_NO_SESS;
+                               goto error;
+                       }
+
+                       /* 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 error;
+                       }
+
+                       get_list_sessions(send_buf + sizeof(struct lttcomm_lttng_msg));
+
+                       ret = send_unix_sock(sock, send_buf, buf_size);
+                       if (ret < 0) {
+                               goto send_error;
                        }
-                       /* Allocated array by ust_list_apps() */
-                       free(pids);
 
                        break;
                }
@@ -492,10 +576,14 @@ static int process_client_msg(int sock, struct lttcomm_session_msg *lsm)
                {
                        /* Undefined command */
                        ret = LTTCOMM_UND;
-                       break;
+                       goto error;
                }
        }
 
+       if (send_buf != NULL) {
+               free(send_buf);
+       }
+
        return 0;
 
 send_error:
@@ -504,6 +592,7 @@ send_error:
 error:
        /* Notify client of error */
        llm.ret_code = ret;
+       llm.size_payload = 0;
        send_unix_sock(sock, (void*) &llm, sizeof(llm));
 
        return -1;
@@ -521,7 +610,8 @@ static void usage(void)
                        "\t-d, --daemonize\t\tStart as a daemon.\n"
                        "\t-g, --group NAME\t\tSpecify the tracing group name. (default: tracing)\n"
                        "\t-V, --version\t\tShow version number.\n"
-                       "\t-S, --sig-parent\t\tSend SIGCHLD to parent pid to notify readiness.\n",
+                       "\t-S, --sig-parent\t\tSend SIGCHLD to parent pid to notify readiness.\n"
+                       "\t-q, --quiet\t\tNo output at all.\n",
                        progname);
 }
 
@@ -540,12 +630,13 @@ static int parse_args(int argc, char **argv)
                { "help", 0, 0, 'h' },
                { "group", 1, 0, 'g' },
                { "version", 0, 0, 'V' },
+               { "quiet", 0, 0, 'q' },
                { NULL, 0, 0, 0 }
        };
 
        while (1) {
                int option_index = 0;
-               c = getopt_long(argc, argv, "dhVS" "a:c:g:s:", long_options, &option_index);
+               c = getopt_long(argc, argv, "dhqVS" "a:c:g:s:", long_options, &option_index);
                if (c == -1) {
                        break;
                }
@@ -578,6 +669,9 @@ static int parse_args(int argc, char **argv)
                case 'S':
                        opt_sig_parent = 1;
                        break;
+               case 'q':
+                       opt_quiet = 1;
+                       break;
                default:
                        /* Unknown option or other error.
                         * Error is printed by getopt, just return */
@@ -688,7 +782,7 @@ static int set_socket_perms(void)
                (grp = getgrnam(default_tracing_group));
 
        if (grp == NULL) {
-               fprintf(stderr, "Missing tracing group. Aborting execution.\n");
+               ERR("Missing tracing group. Aborting execution.\n");
                ret = -1;
                goto end;
        }
@@ -702,48 +796,6 @@ end:
        return ret;
 }
 
-/*
- *     daemonize
- *
- *     Daemonize ltt-sessiond.
- */
-static void daemonize(void)
-{
-       pid_t pid, sid;
-       const char *home_dir = get_home_dir();
-
-       /* Fork off the parent process */
-       if ((pid = fork()) < 0) {
-               perror("fork");
-               exit(EXIT_FAILURE);
-       }
-
-       /* Parent can now exit */
-       if (pid > 0) {
-               exit(EXIT_SUCCESS);
-       }
-
-       /* Change the file mode mask */
-       umask(0);
-
-       /* Create a new SID for the child process */
-       if ((sid = setsid()) < 0) {
-               perror("setsid");
-               exit(EXIT_FAILURE);
-       }
-
-       /* Change the current working directory */
-       if ((chdir(home_dir)) < 0) {
-               perror("chdir");
-               exit(EXIT_FAILURE);
-       }
-
-       /* Close out the standard file descriptors */
-       close(STDIN_FILENO);
-       close(STDOUT_FILENO);
-       close(STDERR_FILENO);
-}
-
 /*
  *     set_signal_handler
  *
@@ -810,8 +862,8 @@ static void sighandler(int sig)
 static void cleanup()
 {
        /* <fun> */
-       fprintf(stdout, "\n\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0);
-       fprintf(stdout, "%c[%d;%dm Matthew, BEET driven development works!%c[%dm\n",27,1,33,27,0);
+       MSG("\n\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0);
+       MSG("%c[%d;%dm Matthew, BEET driven development works!%c[%dm\n",27,1,33,27,0);
        /* </fun> */
 
        unlink(client_unix_sock_path);
@@ -836,7 +888,11 @@ int main(int argc, char **argv)
 
        /* Daemonize */
        if (opt_daemon) {
-               daemonize();
+               ret = daemon(0, 0);
+               if (ret < 0) {
+                       perror("daemon");
+                       goto error;
+               }
        }
 
        /* Check if daemon is UID = 0 */
@@ -870,7 +926,7 @@ int main(int argc, char **argv)
         * socket needed by the daemon are present, this test fails
         */
        if ((ret = check_existing_daemon()) == 0) {
-               fprintf(stderr, "Already running daemon.\n");
+               ERR("Already running daemon.\n");
                goto error;
        }
 
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