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 };
  45
  46 /*
  47  *  lttcom_get_readable_code
  48  *
  49  *  Return ptr to string representing a human readable
  50  *  error code from the lttcomm_return_code enum.
  51  *
  52  *  These code MUST be negative in other to treat that
  53  *  as an error value.
  54  */
  55 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  56 {
  57         int tmp_code = -code;
  58
  59         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  60                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
  61         }
  62
  63         return "Unknown error code";
  64 }
  65
  66 /*
  67  *      lttcomm_connect_unix_sock
  68  *
  69  *      Connect to unix socket using the path name.
  70  */
  71 int lttcomm_connect_unix_sock(const char *pathname)
  72 {
  73         struct sockaddr_un sun;
  74         int fd;
  75         int ret = 1;
  76
  77         fd = socket(PF_UNIX, SOCK_STREAM, 0);
  78         if (fd < 0) {
  79                 perror("socket");
  80                 goto error;
  81         }
  82
  83         memset(&sun, 0, sizeof(sun));
  84         sun.sun_family = AF_UNIX;
  85         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
  86
  87         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
  88         if (ret < 0) {
  89                 perror("connect");
  90                 goto error;
  91         }
  92
  93         return fd;
  94
  95 error:
  96         return -1;
  97 }
  98
  99 /*
 100  *      lttcomm_accept_unix_sock
 101  *
 102  *      Do an accept(2) on the sock and return the
 103  *      new file descriptor. The socket MUST be bind(2) before.
 104  */
 105 int lttcomm_accept_unix_sock(int sock)
 106 {
 107         int new_fd;
 108         struct sockaddr_un sun;
 109         socklen_t len = 0;
 110
 111         /* Blocking call */
 112         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 113         if (new_fd < 0) {
 114                 perror("accept");
 115                 goto error;
 116         }
 117
 118         return new_fd;
 119
 120 error:
 121         return -1;
 122 }
 123
 124 /*
 125  *      lttcomm_create_unix_sock
 126  *
 127  *      Creates a AF_UNIX local socket using pathname
 128  *      bind the socket upon creation and return the fd.
 129  */
 130 int lttcomm_create_unix_sock(const char *pathname)
 131 {
 132         struct sockaddr_un sun;
 133         int fd;
 134         int ret = -1;
 135
 136         /* Create server socket */
 137         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 138                 perror("socket");
 139                 goto error;
 140         }
 141
 142         memset(&sun, 0, sizeof(sun));
 143         sun.sun_family = AF_UNIX;
 144         strncpy(sun.sun_path, pathname, strlen(pathname));
 145
 146         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 147         if (ret < 0) {
 148                 perror("bind");
 149                 goto error;
 150         }
 151
 152         return fd;
 153
 154 error:
 155         return ret;
 156 }
 157
 158 /*
 159  *      lttcomm_listen_unix_sock
 160  *
 161  *      Make the socket listen using MAX_LISTEN.
 162  */
 163 int lttcomm_listen_unix_sock(int sock)
 164 {
 165         int ret;
 166
 167         ret = listen(sock, MAX_LISTEN);
 168         if (ret < 0) {
 169                 perror("listen");
 170         }
 171
 172         return ret;
 173 }
 174
 175 /*
 176  *      lttcomm_recv_unix_sock
 177  *
 178  *  Receive data of size len in put that data into
 179  *  the buf param. Using recvmsg API.
 180  *  Return the size of received data.
 181  */
 182 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 183 {
 184         struct msghdr msg;
 185         struct iovec iov[1];
 186         ssize_t ret = -1;
 187
 188         memset(&msg, 0, sizeof(msg));
 189
 190         iov[0].iov_base = buf;
 191         iov[0].iov_len = len;
 192         msg.msg_iov = iov;
 193         msg.msg_iovlen = 1;
 194
 195         ret = recvmsg(sock, &msg, 0);
 196         if (ret < 0) {
 197                 perror("recvmsg");
 198         }
 199
 200         return ret;
 201 }
 202
 203 /*
 204  *      lttcomm_send_unix_sock
 205  *
 206  *      Send buf data of size len. Using sendmsg API.
 207  *      Return the size of sent data.
 208  */
 209 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 210 {
 211         struct msghdr msg;
 212         struct iovec iov[1];
 213         ssize_t ret = -1;
 214
 215         memset(&msg, 0, sizeof(msg));
 216
 217         iov[0].iov_base = buf;
 218         iov[0].iov_len = len;
 219         msg.msg_iov = iov;
 220         msg.msg_iovlen = 1;
 221
 222         ret = sendmsg(sock, &msg, 0);
 223         if (ret < 0) {
 224                 perror("sendmsg");
 225         }
 226
 227         return ret;
 228 }
 229
 230 /*
 231  *  lttcomm_close_unix_sock
 232  *
 233  *  Shutdown cleanly a unix socket.
 234  */
 235 int lttcomm_close_unix_sock(int sock)
 236 {
 237         int ret;
 238
 239         /* Shutdown receptions and transmissions */
 240         ret = shutdown(sock, SHUT_RDWR);
 241         if (ret < 0) {
 242                 perror("shutdown");
 243         }
 244
 245         return ret;
 246 }