liblttsessiondcomm/liblttsessiondcomm.c

   1 /*
   2  * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; only version 2
   7  * of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <limits.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/socket.h>
  25 #include <sys/stat.h>
  26 #include <sys/types.h>
  27 #include <sys/un.h>
  28 #include <unistd.h>
  29
  30 #include "liblttsessiondcomm.h"
  31
  32 /*
  33  * Human readable error message.
  34  */
  35 static const char *lttcomm_readable_code[] = {
  36         [ LTTCOMM_ERR_INDEX(LTTCOMM_OK) ] = "Success",
  37         [ LTTCOMM_ERR_INDEX(LTTCOMM_ERR) ] = "Unknown error",
  38         [ LTTCOMM_ERR_INDEX(LTTCOMM_UND) ] = "Undefined command",
  39         [ LTTCOMM_ERR_INDEX(LTTCOMM_NOT_IMPLEMENTED) ] = "Not implemented",
  40         [ LTTCOMM_ERR_INDEX(LTTCOMM_UNKNOWN_DOMAIN) ] = "Unknown tracing domain",
  41         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_SESSION) ] = "No session found",
  42         [ LTTCOMM_ERR_INDEX(LTTCOMM_LIST_FAIL) ] = "Unable to list traceable apps",
  43         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_APPS) ] = "No traceable apps found",
  44         [ LTTCOMM_ERR_INDEX(LTTCOMM_SESS_NOT_FOUND) ] = "Session name not found",
  45         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACE) ] = "No trace found",
  46         [ LTTCOMM_ERR_INDEX(LTTCOMM_FATAL) ] = "Fatal error of the session daemon",
  47         [ LTTCOMM_ERR_INDEX(LTTCOMM_CREATE_FAIL) ] = "Create trace failed",
  48         [ LTTCOMM_ERR_INDEX(LTTCOMM_START_FAIL) ] = "Start trace failed",
  49         [ LTTCOMM_ERR_INDEX(LTTCOMM_STOP_FAIL) ] = "Stop trace failed",
  50         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACEABLE) ] = "App is not traceable",
  51         [ LTTCOMM_ERR_INDEX(LTTCOMM_SELECT_SESS) ] = "A session MUST be selected",
  52         [ LTTCOMM_ERR_INDEX(LTTCOMM_EXIST_SESS) ] = "Session name already exist",
  53         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NA) ] = "Kernel tracer not available",
  54         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_EVENT_EXIST) ] = "Kernel event already exists",
  55         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_SESS_FAIL) ] = "Kernel create session failed",
  56         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_FAIL) ] = "Kernel create channel failed",
  57         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_NOT_FOUND) ] = "Kernel channel not found",
  58         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_DISABLE_FAIL) ] = "Disable kernel channel failed",
  59         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_ENABLE_FAIL) ] = "Enable kernel channel failed",
  60         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONTEXT_FAIL) ] = "Add kernel context failed",
  61         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
  62         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
  63         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
  64         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_START_FAIL) ] = "Starting kernel trace failed",
  65         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STOP_FAIL) ] = "Stoping kernel trace failed",
  66         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONSUMER_FAIL) ] = "Kernel consumer start failed",
  67         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STREAM_FAIL) ] = "Kernel create stream failed",
  68         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_FAIL) ] = "Kernel trace directory creation failed",
  69         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_EXIST) ] = "Kernel trace directory already exist",
  70         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
  71         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
  72         [ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
  73         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
  74         [ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
  75         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_ERROR) ] = "Kconsumerd error in polling thread",
  76         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_NVAL) ] = "Kconsumerd polling on closed fd",
  77         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_HUP) ] = "Kconsumerd all fd hung up",
  78         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
  79         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
  80         [ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
  81         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
  82         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
  83         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
  84         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
  85         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
  86 };
  87
  88 /*
  89  *  lttcom_get_readable_code
  90  *
  91  *  Return ptr to string representing a human readable
  92  *  error code from the lttcomm_return_code enum.
  93  *
  94  *  These code MUST be negative in other to treat that
  95  *  as an error value.
  96  */
  97 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  98 {
  99         int tmp_code = -code;
 100
 101         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
 102                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
 103         }
 104
 105         return "Unknown error code";
 106 }
 107
 108 /*
 109  *      lttcomm_connect_unix_sock
 110  *
 111  *      Connect to unix socket using the path name.
 112  */
 113 int lttcomm_connect_unix_sock(const char *pathname)
 114 {
 115         struct sockaddr_un sun;
 116         int fd;
 117         int ret = 1;
 118
 119         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 120         if (fd < 0) {
 121                 perror("socket");
 122                 goto error;
 123         }
 124
 125         memset(&sun, 0, sizeof(sun));
 126         sun.sun_family = AF_UNIX;
 127         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 128
 129         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 130         if (ret < 0) {
 131                 perror("connect");
 132                 goto error;
 133         }
 134
 135         return fd;
 136
 137 error:
 138         return -1;
 139 }
 140
 141 /*
 142  *      lttcomm_accept_unix_sock
 143  *
 144  *      Do an accept(2) on the sock and return the
 145  *      new file descriptor. The socket MUST be bind(2) before.
 146  */
 147 int lttcomm_accept_unix_sock(int sock)
 148 {
 149         int new_fd;
 150         struct sockaddr_un sun;
 151         socklen_t len = 0;
 152
 153         /* Blocking call */
 154         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 155         if (new_fd < 0) {
 156                 perror("accept");
 157                 goto error;
 158         }
 159
 160         return new_fd;
 161
 162 error:
 163         return -1;
 164 }
 165
 166 /*
 167  *      lttcomm_create_unix_sock
 168  *
 169  *      Creates a AF_UNIX local socket using pathname
 170  *      bind the socket upon creation and return the fd.
 171  */
 172 int lttcomm_create_unix_sock(const char *pathname)
 173 {
 174         struct sockaddr_un sun;
 175         int fd;
 176         int ret = -1;
 177
 178         /* Create server socket */
 179         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 180                 perror("socket");
 181                 goto error;
 182         }
 183
 184         memset(&sun, 0, sizeof(sun));
 185         sun.sun_family = AF_UNIX;
 186         strncpy(sun.sun_path, pathname, strlen(pathname));
 187
 188         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 189         if (ret < 0) {
 190                 perror("bind");
 191                 goto error;
 192         }
 193
 194         return fd;
 195
 196 error:
 197         return ret;
 198 }
 199
 200 /*
 201  *      lttcomm_listen_unix_sock
 202  *
 203  *      Make the socket listen using MAX_LISTEN.
 204  */
 205 int lttcomm_listen_unix_sock(int sock)
 206 {
 207         int ret;
 208
 209         ret = listen(sock, MAX_LISTEN);
 210         if (ret < 0) {
 211                 perror("listen");
 212         }
 213
 214         return ret;
 215 }
 216
 217 /*
 218  *      lttcomm_recv_unix_sock
 219  *
 220  *  Receive data of size len in put that data into
 221  *  the buf param. Using recvmsg API.
 222  *  Return the size of received data.
 223  */
 224 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 225 {
 226         struct msghdr msg;
 227         struct iovec iov[1];
 228         ssize_t ret = -1;
 229
 230         memset(&msg, 0, sizeof(msg));
 231
 232         iov[0].iov_base = buf;
 233         iov[0].iov_len = len;
 234         msg.msg_iov = iov;
 235         msg.msg_iovlen = 1;
 236
 237         ret = recvmsg(sock, &msg, 0);
 238         if (ret < 0) {
 239                 perror("recvmsg");
 240         }
 241
 242         return ret;
 243 }
 244
 245 /*
 246  *      lttcomm_send_unix_sock
 247  *
 248  *      Send buf data of size len. Using sendmsg API.
 249  *      Return the size of sent data.
 250  */
 251 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 252 {
 253         struct msghdr msg;
 254         struct iovec iov[1];
 255         ssize_t ret = -1;
 256
 257         memset(&msg, 0, sizeof(msg));
 258
 259         iov[0].iov_base = buf;
 260         iov[0].iov_len = len;
 261         msg.msg_iov = iov;
 262         msg.msg_iovlen = 1;
 263
 264         ret = sendmsg(sock, &msg, 0);
 265         if (ret < 0) {
 266                 perror("sendmsg");
 267         }
 268
 269         return ret;
 270 }
 271
 272 /*
 273  *  lttcomm_close_unix_sock
 274  *
 275  *  Shutdown cleanly a unix socket.
 276  */
 277 int lttcomm_close_unix_sock(int sock)
 278 {
 279         int ret;
 280
 281         /* Shutdown receptions and transmissions */
 282         ret = shutdown(sock, SHUT_RDWR);
 283         if (ret < 0) {
 284                 perror("shutdown");
 285         }
 286
 287         return ret;
 288 }
 289
 290 /*
 291  *  lttcomm_send_fds_unix_sock
 292  *
 293  *  Send multiple fds on a unix socket.
 294  */
 295 ssize_t lttcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len)
 296 {
 297         struct msghdr msg;
 298         struct cmsghdr *cmptr;
 299         struct iovec iov[1];
 300         ssize_t ret = -1;
 301         unsigned int sizeof_fds = nb_fd * sizeof(int);
 302         char tmp[CMSG_SPACE(sizeof_fds)];
 303
 304         memset(&msg, 0, sizeof(msg));
 305
 306         msg.msg_control = (caddr_t)tmp;
 307         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 308
 309         cmptr = CMSG_FIRSTHDR(&msg);
 310         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 311         cmptr->cmsg_level = SOL_SOCKET;
 312         cmptr->cmsg_type = SCM_RIGHTS;
 313         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 314
 315         iov[0].iov_base = buf;
 316         iov[0].iov_len = len;
 317         msg.msg_iov = iov;
 318         msg.msg_iovlen = 1;
 319
 320         ret = sendmsg(sock, &msg, 0);
 321         if (ret < 0) {
 322                 perror("sendmsg");
 323         }
 324
 325         return ret;
 326 }