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; either version 2
   7  * of the License, or (at your option) any later version.
   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_NO_SESSION) ] = "No session found",
  40         [ LTTCOMM_ERR_INDEX(LTTCOMM_LIST_FAIL) ] = "Unable to list traceable apps",
  41         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_APPS) ] = "No traceable apps found",
  42         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_SESS) ] = "No session found",
  43         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACE) ] = "No trace found",
  44         [ LTTCOMM_ERR_INDEX(LTTCOMM_FATAL) ] = "Fatal error of the session daemon",
  45         [ LTTCOMM_ERR_INDEX(LTTCOMM_CREATE_FAIL) ] = "Create trace failed",
  46         [ LTTCOMM_ERR_INDEX(LTTCOMM_START_FAIL) ] = "Start trace failed",
  47         [ LTTCOMM_ERR_INDEX(LTTCOMM_STOP_FAIL) ] = "Stop trace failed",
  48         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACEABLE) ] = "App is not traceable",
  49         [ LTTCOMM_ERR_INDEX(LTTCOMM_SELECT_SESS) ] = "A session MUST be selected",
  50         [ LTTCOMM_ERR_INDEX(LTTCOMM_EXIST_SESS) ] = "Session name already exist",
  51         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NA) ] = "Kernel tracer not available",
  52         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_SESS_FAIL) ] = "Kernel create session failed",
  53         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_FAIL) ] = "Kernel create channel failed",
  54         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
  55         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
  56         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
  57         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_START_FAIL) ] = "Starting kernel trace failed",
  58         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STOP_FAIL) ] = "Stoping kernel trace failed",
  59         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONSUMER_FAIL) ] = "Kernel consumer start failed",
  60         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STREAM_FAIL) ] = "Kernel create stream failed",
  61         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_FAIL) ] = "Kernel trace directory creation failed",
  62         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_EXIST) ] = "Kernel trace directory already exist",
  63         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
  64         [ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
  65         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
  66         [ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
  67         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_ERROR) ] = "Kconsumerd error in polling thread",
  68         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_NVAL) ] = "Kconsumerd polling on closed fd",
  69         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_HUP) ] = "Kconsumerd all fd hung up",
  70         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
  71         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
  72         [ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
  73         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
  74         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
  75         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
  76         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
  77         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "No event found",
  78 };
  79
  80 /*
  81  *  lttcom_get_readable_code
  82  *
  83  *  Return ptr to string representing a human readable
  84  *  error code from the lttcomm_return_code enum.
  85  *
  86  *  These code MUST be negative in other to treat that
  87  *  as an error value.
  88  */
  89 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  90 {
  91         int tmp_code = -code;
  92
  93         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  94                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
  95         }
  96
  97         return "Unknown error code";
  98 }
  99
 100 /*
 101  *      lttcomm_connect_unix_sock
 102  *
 103  *      Connect to unix socket using the path name.
 104  */
 105 int lttcomm_connect_unix_sock(const char *pathname)
 106 {
 107         struct sockaddr_un sun;
 108         int fd;
 109         int ret = 1;
 110
 111         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 112         if (fd < 0) {
 113                 perror("socket");
 114                 goto error;
 115         }
 116
 117         memset(&sun, 0, sizeof(sun));
 118         sun.sun_family = AF_UNIX;
 119         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 120
 121         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 122         if (ret < 0) {
 123                 perror("connect");
 124                 goto error;
 125         }
 126
 127         return fd;
 128
 129 error:
 130         return -1;
 131 }
 132
 133 /*
 134  *      lttcomm_accept_unix_sock
 135  *
 136  *      Do an accept(2) on the sock and return the
 137  *      new file descriptor. The socket MUST be bind(2) before.
 138  */
 139 int lttcomm_accept_unix_sock(int sock)
 140 {
 141         int new_fd;
 142         struct sockaddr_un sun;
 143         socklen_t len = 0;
 144
 145         /* Blocking call */
 146         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 147         if (new_fd < 0) {
 148                 perror("accept");
 149                 goto error;
 150         }
 151
 152         return new_fd;
 153
 154 error:
 155         return -1;
 156 }
 157
 158 /*
 159  *      lttcomm_create_unix_sock
 160  *
 161  *      Creates a AF_UNIX local socket using pathname
 162  *      bind the socket upon creation and return the fd.
 163  */
 164 int lttcomm_create_unix_sock(const char *pathname)
 165 {
 166         struct sockaddr_un sun;
 167         int fd;
 168         int ret = -1;
 169
 170         /* Create server socket */
 171         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 172                 perror("socket");
 173                 goto error;
 174         }
 175
 176         memset(&sun, 0, sizeof(sun));
 177         sun.sun_family = AF_UNIX;
 178         strncpy(sun.sun_path, pathname, strlen(pathname));
 179
 180         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 181         if (ret < 0) {
 182                 perror("bind");
 183                 goto error;
 184         }
 185
 186         return fd;
 187
 188 error:
 189         return ret;
 190 }
 191
 192 /*
 193  *      lttcomm_listen_unix_sock
 194  *
 195  *      Make the socket listen using MAX_LISTEN.
 196  */
 197 int lttcomm_listen_unix_sock(int sock)
 198 {
 199         int ret;
 200
 201         ret = listen(sock, MAX_LISTEN);
 202         if (ret < 0) {
 203                 perror("listen");
 204         }
 205
 206         return ret;
 207 }
 208
 209 /*
 210  *      lttcomm_recv_unix_sock
 211  *
 212  *  Receive data of size len in put that data into
 213  *  the buf param. Using recvmsg API.
 214  *  Return the size of received data.
 215  */
 216 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 217 {
 218         struct msghdr msg;
 219         struct iovec iov[1];
 220         ssize_t ret = -1;
 221
 222         memset(&msg, 0, sizeof(msg));
 223
 224         iov[0].iov_base = buf;
 225         iov[0].iov_len = len;
 226         msg.msg_iov = iov;
 227         msg.msg_iovlen = 1;
 228
 229         ret = recvmsg(sock, &msg, 0);
 230         if (ret < 0) {
 231                 perror("recvmsg");
 232         }
 233
 234         return ret;
 235 }
 236
 237 /*
 238  *      lttcomm_send_unix_sock
 239  *
 240  *      Send buf data of size len. Using sendmsg API.
 241  *      Return the size of sent data.
 242  */
 243 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 244 {
 245         struct msghdr msg;
 246         struct iovec iov[1];
 247         ssize_t ret = -1;
 248
 249         memset(&msg, 0, sizeof(msg));
 250
 251         iov[0].iov_base = buf;
 252         iov[0].iov_len = len;
 253         msg.msg_iov = iov;
 254         msg.msg_iovlen = 1;
 255
 256         ret = sendmsg(sock, &msg, 0);
 257         if (ret < 0) {
 258                 perror("sendmsg");
 259         }
 260
 261         return ret;
 262 }
 263
 264 /*
 265  *  lttcomm_close_unix_sock
 266  *
 267  *  Shutdown cleanly a unix socket.
 268  */
 269 int lttcomm_close_unix_sock(int sock)
 270 {
 271         int ret;
 272
 273         /* Shutdown receptions and transmissions */
 274         ret = shutdown(sock, SHUT_RDWR);
 275         if (ret < 0) {
 276                 perror("shutdown");
 277         }
 278
 279         return ret;
 280 }
 281
 282 /*
 283  *  lttcomm_send_fds_unix_sock
 284  *
 285  *  Send multiple fds on a unix socket.
 286  */
 287 ssize_t lttcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len)
 288 {
 289         struct msghdr msg;
 290         struct cmsghdr *cmptr;
 291         struct iovec iov[1];
 292         ssize_t ret = -1;
 293         unsigned int sizeof_fds = nb_fd * sizeof(int);
 294         char tmp[CMSG_SPACE(sizeof_fds)];
 295
 296         memset(&msg, 0, sizeof(msg));
 297
 298         msg.msg_control = (caddr_t)tmp;
 299         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 300
 301         cmptr = CMSG_FIRSTHDR(&msg);
 302         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 303         cmptr->cmsg_level = SOL_SOCKET;
 304         cmptr->cmsg_type = SCM_RIGHTS;
 305         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 306
 307         iov[0].iov_base = buf;
 308         iov[0].iov_len = len;
 309         msg.msg_iov = iov;
 310         msg.msg_iovlen = 1;
 311
 312         ret = sendmsg(sock, &msg, 0);
 313         if (ret < 0) {
 314                 perror("sendmsg");
 315         }
 316
 317         return ret;
 318 }