| 1 | /* |
| 2 | * lttng-ust-comm.c |
| 3 | * |
| 4 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> |
| 5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6 | * |
| 7 | * This library is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; only |
| 10 | * version 2.1 of the License. |
| 11 | * |
| 12 | * This library is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with this library; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | #include <sys/types.h> |
| 23 | #include <sys/socket.h> |
| 24 | #include <unistd.h> |
| 25 | #include <errno.h> |
| 26 | #include <lttng-sessiond-comm.h> |
| 27 | #include <ust/usterr-signal-safe.h> |
| 28 | #include <pthread.h> |
| 29 | |
| 30 | /* Socket from app (connect) to session daemon (listen) for communication */ |
| 31 | static int global_apps_socket = -1; |
| 32 | static char global_apps_sock_path[PATH_MAX] = DEFAULT_GLOBAL_APPS_UNIX_SOCK; |
| 33 | static pthread_t global_ust_listener; |
| 34 | |
| 35 | /* TODO: allow global_apps_sock_path override */ |
| 36 | |
| 37 | static int local_apps_socket = -1; |
| 38 | static char local_apps_sock_path[PATH_MAX]; |
| 39 | static pthread_t local_ust_listener; |
| 40 | |
| 41 | static |
| 42 | int connect_global_apps_socket(void) |
| 43 | { |
| 44 | int ret; |
| 45 | |
| 46 | ret = lttcomm_connect_unix_sock(global_apps_sock_path); |
| 47 | if (ret < 0) |
| 48 | return ret; |
| 49 | global_apps_socket = ret; |
| 50 | |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | static |
| 55 | int connect_local_apps_socket(void) |
| 56 | { |
| 57 | const char *home_dir; |
| 58 | int ret; |
| 59 | |
| 60 | home_dir = (const char *) getenv("HOME"); |
| 61 | if (!home_dir) |
| 62 | return -ENOENT; |
| 63 | snprintf(local_apps_sock_path, PATH_MAX, |
| 64 | DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); |
| 65 | |
| 66 | ret = lttcomm_connect_unix_sock(local_apps_sock_path); |
| 67 | if (ret < 0) |
| 68 | return ret; |
| 69 | local_apps_socket = ret; |
| 70 | |
| 71 | |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | static |
| 76 | int register_app_to_sessiond(int socket) |
| 77 | { |
| 78 | ssize_t ret; |
| 79 | struct { |
| 80 | pid_t pid; |
| 81 | uid_t uid; |
| 82 | } reg_msg; |
| 83 | |
| 84 | reg_msg.pid = getpid(); |
| 85 | reg_msg.uid = getuid(); |
| 86 | |
| 87 | ret = lttcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg)); |
| 88 | if (ret >= 0 && ret != sizeof(reg_msg)) |
| 89 | return -EIO; |
| 90 | return ret; |
| 91 | } |
| 92 | |
| 93 | |
| 94 | static |
| 95 | int parse_message(struct lttcomm_session_msg *lsm) |
| 96 | { |
| 97 | switch (lsm->cmd_type) { |
| 98 | case LTTNG_CREATE_SESSION: |
| 99 | DBG("Handling create session message"); |
| 100 | |
| 101 | |
| 102 | break; |
| 103 | default: |
| 104 | ERR("Unimplemented command %d", (int) lsm->cmd_type); |
| 105 | return -1; |
| 106 | } |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static |
| 111 | void *ust_listener_thread(void *arg) |
| 112 | { |
| 113 | int sock = *(int *) arg; |
| 114 | int ret; |
| 115 | |
| 116 | for (;;) { |
| 117 | ssize_t len; |
| 118 | struct lttcomm_session_msg lsm; |
| 119 | |
| 120 | /* Receive session handle */ |
| 121 | len = lttcomm_recv_unix_sock(sock, &lsm, sizeof(lsm)); |
| 122 | switch (len) { |
| 123 | case 0: /* orderly shutdown */ |
| 124 | DBG("ltt-sessiond has performed an orderly shutdown\n"); |
| 125 | goto end; |
| 126 | case sizeof(lsm): |
| 127 | DBG("message received\n"); |
| 128 | ret = parse_message(&lsm); |
| 129 | if (ret) { |
| 130 | ERR("Error parsing message\n"); |
| 131 | } |
| 132 | continue; |
| 133 | case -1: |
| 134 | if (errno == ECONNRESET) { |
| 135 | ERR("remote end closed connection\n"); |
| 136 | goto end; |
| 137 | } |
| 138 | goto end; |
| 139 | default: |
| 140 | ERR("incorrect message size: %zd\n", len); |
| 141 | continue; |
| 142 | } |
| 143 | |
| 144 | } |
| 145 | end: |
| 146 | return NULL; |
| 147 | } |
| 148 | |
| 149 | |
| 150 | /* |
| 151 | * sessiond monitoring thread: monitor presence of global and per-user |
| 152 | * sessiond by polling the application common named pipe. |
| 153 | */ |
| 154 | /* TODO */ |
| 155 | |
| 156 | void __attribute__((constructor)) lttng_ust_comm_init(void) |
| 157 | { |
| 158 | int ret; |
| 159 | |
| 160 | init_usterr(); |
| 161 | |
| 162 | #if 0 |
| 163 | /* Connect to the global sessiond apps socket */ |
| 164 | ret = connect_global_apps_socket(); |
| 165 | if (ret) { |
| 166 | ERR("Error connecting to global apps socket"); |
| 167 | } |
| 168 | #endif //0 |
| 169 | |
| 170 | /* Connect to the per-user (local) sessiond apps socket */ |
| 171 | ret = connect_local_apps_socket(); |
| 172 | if (ret) { |
| 173 | ERR("Error connecting to local apps socket"); |
| 174 | } |
| 175 | |
| 176 | if (global_apps_socket >= 0) { |
| 177 | ret = register_app_to_sessiond(global_apps_socket); |
| 178 | if (ret < 0) { |
| 179 | ERR("Error registering app to global apps socket"); |
| 180 | } |
| 181 | } |
| 182 | if (local_apps_socket >= 0) { |
| 183 | ret = register_app_to_sessiond(local_apps_socket); |
| 184 | if (ret < 0) { |
| 185 | ERR("Error registering app to local apps socket"); |
| 186 | } |
| 187 | ret = pthread_create(&local_ust_listener, NULL, |
| 188 | ust_listener_thread, &local_apps_socket); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | void __attribute__((destructor)) lttng_ust_comm_exit(void) |
| 193 | { |
| 194 | int ret; |
| 195 | |
| 196 | #if 0 |
| 197 | ERR("dest %d", global_apps_socket); |
| 198 | if (global_apps_socket >= 0) { |
| 199 | ret = unregister_app_to_sessiond(global_apps_socket); |
| 200 | if (ret < 0) { |
| 201 | ERR("Error registering app to global apps socket"); |
| 202 | } |
| 203 | ret = close(global_apps_socket); |
| 204 | if (ret) { |
| 205 | ERR("Error closing global apps socket"); |
| 206 | } |
| 207 | } |
| 208 | #endif |
| 209 | if (local_apps_socket >= 0) { |
| 210 | /* |
| 211 | * Using pthread_cancel here because: |
| 212 | * A) we don't want to hang application teardown. |
| 213 | * B) the thread is not allocating any resource. |
| 214 | */ |
| 215 | ret = pthread_cancel(local_ust_listener); |
| 216 | if (ret) { |
| 217 | ERR("Error joining local ust listener thread"); |
| 218 | } |
| 219 | |
| 220 | ret = close(local_apps_socket); |
| 221 | if (ret) { |
| 222 | ERR("Error closing local apps socket"); |
| 223 | } |
| 224 | } |
| 225 | } |