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_FATAL) ] = "Fatal error of the session daemon",
  44         [ LTTCOMM_ERR_INDEX(LTTCOMM_CREATE_FAIL) ] = "Create trace failed",
  45         [ LTTCOMM_ERR_INDEX(LTTCOMM_START_FAIL) ] = "Start trace failed",
  46         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACEABLE) ] = "App is not traceable",
  47         [ LTTCOMM_ERR_INDEX(LTTCOMM_SELECT_SESS) ] = "A session MUST be selected",
  48 };
  49
  50 /*
  51  *  lttcom_get_readable_code
  52  *
  53  *  Return ptr to string representing a human readable
  54  *  error code from the lttcomm_return_code enum.
  55  *
  56  *  These code MUST be negative in other to treat that
  57  *  as an error value.
  58  */
  59 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  60 {
  61         int tmp_code = -code;
  62
  63         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  64                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
  65         }
  66
  67         return "Unknown error code";
  68 }
  69
  70 /*
  71  *      lttcomm_connect_unix_sock
  72  *
  73  *      Connect to unix socket using the path name.
  74  */
  75 int lttcomm_connect_unix_sock(const char *pathname)
  76 {
  77         struct sockaddr_un sun;
  78         int fd;
  79         int ret = 1;
  80
  81         fd = socket(PF_UNIX, SOCK_STREAM, 0);
  82         if (fd < 0) {
  83                 perror("socket");
  84                 goto error;
  85         }
  86
  87         memset(&sun, 0, sizeof(sun));
  88         sun.sun_family = AF_UNIX;
  89         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
  90
  91         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
  92         if (ret < 0) {
  93                 perror("connect");
  94                 goto error;
  95         }
  96
  97         return fd;
  98
  99 error:
 100         return -1;
 101 }
 102
 103 /*
 104  *      lttcomm_accept_unix_sock
 105  *
 106  *      Do an accept(2) on the sock and return the
 107  *      new file descriptor. The socket MUST be bind(2) before.
 108  */
 109 int lttcomm_accept_unix_sock(int sock)
 110 {
 111         int new_fd;
 112         struct sockaddr_un sun;
 113         socklen_t len = 0;
 114
 115         /* Blocking call */
 116         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 117         if (new_fd < 0) {
 118                 perror("accept");
 119                 goto error;
 120         }
 121
 122         return new_fd;
 123
 124 error:
 125         return -1;
 126 }
 127
 128 /*
 129  *      lttcomm_create_unix_sock
 130  *
 131  *      Creates a AF_UNIX local socket using pathname
 132  *      bind the socket upon creation and return the fd.
 133  */
 134 int lttcomm_create_unix_sock(const char *pathname)
 135 {
 136         struct sockaddr_un sun;
 137         int fd;
 138         int ret = -1;
 139
 140         /* Create server socket */
 141         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 142                 perror("socket");
 143                 goto error;
 144         }
 145
 146         memset(&sun, 0, sizeof(sun));
 147         sun.sun_family = AF_UNIX;
 148         strncpy(sun.sun_path, pathname, strlen(pathname));
 149
 150         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 151         if (ret < 0) {
 152                 perror("bind");
 153                 goto error;
 154         }
 155
 156         return fd;
 157
 158 error:
 159         return ret;
 160 }
 161
 162 /*
 163  *      lttcomm_listen_unix_sock
 164  *
 165  *      Make the socket listen using MAX_LISTEN.
 166  */
 167 int lttcomm_listen_unix_sock(int sock)
 168 {
 169         int ret;
 170
 171         ret = listen(sock, MAX_LISTEN);
 172         if (ret < 0) {
 173                 perror("listen");
 174         }
 175
 176         return ret;
 177 }
 178
 179 /*
 180  *      lttcomm_recv_unix_sock
 181  *
 182  *  Receive data of size len in put that data into
 183  *  the buf param. Using recvmsg API.
 184  *  Return the size of received data.
 185  */
 186 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 187 {
 188         struct msghdr msg;
 189         struct iovec iov[1];
 190         ssize_t ret = -1;
 191
 192         memset(&msg, 0, sizeof(msg));
 193
 194         iov[0].iov_base = buf;
 195         iov[0].iov_len = len;
 196         msg.msg_iov = iov;
 197         msg.msg_iovlen = 1;
 198
 199         ret = recvmsg(sock, &msg, 0);
 200         if (ret < 0) {
 201                 perror("recvmsg");
 202         }
 203
 204         return ret;
 205 }
 206
 207 /*
 208  *      lttcomm_send_unix_sock
 209  *
 210  *      Send buf data of size len. Using sendmsg API.
 211  *      Return the size of sent data.
 212  */
 213 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 214 {
 215         struct msghdr msg;
 216         struct iovec iov[1];
 217         ssize_t ret = -1;
 218
 219         memset(&msg, 0, sizeof(msg));
 220
 221         iov[0].iov_base = buf;
 222         iov[0].iov_len = len;
 223         msg.msg_iov = iov;
 224         msg.msg_iovlen = 1;
 225
 226         ret = sendmsg(sock, &msg, 0);
 227         if (ret < 0) {
 228                 perror("sendmsg");
 229         }
 230
 231         return ret;
 232 }
 233
 234 /*
 235  *  lttcomm_close_unix_sock
 236  *
 237  *  Shutdown cleanly a unix socket.
 238  */
 239 int lttcomm_close_unix_sock(int sock)
 240 {
 241         int ret;
 242
 243         /* Shutdown receptions and transmissions */
 244         ret = shutdown(sock, SHUT_RDWR);
 245         if (ret < 0) {
 246                 perror("shutdown");
 247         }
 248
 249         return ret;
 250 }