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 };
  46
  47 /*
  48  *  lttcom_get_readable_code
  49  *
  50  *  Return ptr to string representing a human readable
  51  *  error code from the lttcomm_return_code enum.
  52  *
  53  *  These code MUST be negative in other to treat that
  54  *  as an error value.
  55  */
  56 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  57 {
  58         int tmp_code = -code;
  59
  60         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  61                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
  62         }
  63
  64         return "Unknown error code";
  65 }
  66
  67 /*
  68  *      lttcomm_connect_unix_sock
  69  *
  70  *      Connect to unix socket using the path name.
  71  */
  72 int lttcomm_connect_unix_sock(const char *pathname)
  73 {
  74         struct sockaddr_un sun;
  75         int fd;
  76         int ret = 1;
  77
  78         fd = socket(PF_UNIX, SOCK_STREAM, 0);
  79         if (fd < 0) {
  80                 perror("socket");
  81                 goto error;
  82         }
  83
  84         memset(&sun, 0, sizeof(sun));
  85         sun.sun_family = AF_UNIX;
  86         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
  87
  88         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
  89         if (ret < 0) {
  90                 perror("connect");
  91                 goto error;
  92         }
  93
  94         return fd;
  95
  96 error:
  97         return -1;
  98 }
  99
 100 /*
 101  *      lttcomm_accept_unix_sock
 102  *
 103  *      Do an accept(2) on the sock and return the
 104  *      new file descriptor. The socket MUST be bind(2) before.
 105  */
 106 int lttcomm_accept_unix_sock(int sock)
 107 {
 108         int new_fd;
 109         struct sockaddr_un sun;
 110         socklen_t len = 0;
 111
 112         /* Blocking call */
 113         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 114         if (new_fd < 0) {
 115                 perror("accept");
 116                 goto error;
 117         }
 118
 119         return new_fd;
 120
 121 error:
 122         return -1;
 123 }
 124
 125 /*
 126  *      lttcomm_create_unix_sock
 127  *
 128  *      Creates a AF_UNIX local socket using pathname
 129  *      bind the socket upon creation and return the fd.
 130  */
 131 int lttcomm_create_unix_sock(const char *pathname)
 132 {
 133         struct sockaddr_un sun;
 134         int fd;
 135         int ret = -1;
 136
 137         /* Create server socket */
 138         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 139                 perror("socket");
 140                 goto error;
 141         }
 142
 143         memset(&sun, 0, sizeof(sun));
 144         sun.sun_family = AF_UNIX;
 145         strncpy(sun.sun_path, pathname, strlen(pathname));
 146
 147         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 148         if (ret < 0) {
 149                 perror("bind");
 150                 goto error;
 151         }
 152
 153         return fd;
 154
 155 error:
 156         return ret;
 157 }
 158
 159 /*
 160  *      lttcomm_listen_unix_sock
 161  *
 162  *      Make the socket listen using MAX_LISTEN.
 163  */
 164 int lttcomm_listen_unix_sock(int sock)
 165 {
 166         int ret;
 167
 168         ret = listen(sock, MAX_LISTEN);
 169         if (ret < 0) {
 170                 perror("listen");
 171         }
 172
 173         return ret;
 174 }
 175
 176 /*
 177  *      lttcomm_recv_unix_sock
 178  *
 179  *  Receive data of size len in put that data into
 180  *  the buf param. Using recvmsg API.
 181  *  Return the size of received data.
 182  */
 183 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 184 {
 185         struct msghdr msg;
 186         struct iovec iov[1];
 187         ssize_t ret = -1;
 188
 189         memset(&msg, 0, sizeof(msg));
 190
 191         iov[0].iov_base = buf;
 192         iov[0].iov_len = len;
 193         msg.msg_iov = iov;
 194         msg.msg_iovlen = 1;
 195
 196         ret = recvmsg(sock, &msg, 0);
 197         if (ret < 0) {
 198                 perror("recvmsg");
 199         }
 200
 201         return ret;
 202 }
 203
 204 /*
 205  *      lttcomm_send_unix_sock
 206  *
 207  *      Send buf data of size len. Using sendmsg API.
 208  *      Return the size of sent data.
 209  */
 210 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 211 {
 212         struct msghdr msg;
 213         struct iovec iov[1];
 214         ssize_t ret = -1;
 215
 216         memset(&msg, 0, sizeof(msg));
 217
 218         iov[0].iov_base = buf;
 219         iov[0].iov_len = len;
 220         msg.msg_iov = iov;
 221         msg.msg_iovlen = 1;
 222
 223         ret = sendmsg(sock, &msg, 0);
 224         if (ret < 0) {
 225                 perror("sendmsg");
 226         }
 227
 228         return ret;
 229 }
 230
 231 /*
 232  *  lttcomm_close_unix_sock
 233  *
 234  *  Shutdown cleanly a unix socket.
 235  */
 236 int lttcomm_close_unix_sock(int sock)
 237 {
 238         int ret;
 239
 240         /* Shutdown receptions and transmissions */
 241         ret = shutdown(sock, SHUT_RDWR);
 242         if (ret < 0) {
 243                 perror("shutdown");
 244         }
 245
 246         return ret;
 247 }