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(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
  65         [ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
  66         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
  67         [ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
  68         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_ERROR) ] = "Kconsumerd error in polling thread",
  69         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_NVAL) ] = "Kconsumerd polling on closed fd",
  70         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_HUP) ] = "Kconsumerd all fd hung up",
  71         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
  72         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
  73         [ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
  74         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
  75         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
  76         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
  77         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
  78         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "No event found",
  79 };
  80
  81 /*
  82  *  lttcom_get_readable_code
  83  *
  84  *  Return ptr to string representing a human readable
  85  *  error code from the lttcomm_return_code enum.
  86  *
  87  *  These code MUST be negative in other to treat that
  88  *  as an error value.
  89  */
  90 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  91 {
  92         int tmp_code = -code;
  93
  94         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  95                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
  96         }
  97
  98         return "Unknown error code";
  99 }
 100
 101 /*
 102  *      lttcomm_connect_unix_sock
 103  *
 104  *      Connect to unix socket using the path name.
 105  */
 106 int lttcomm_connect_unix_sock(const char *pathname)
 107 {
 108         struct sockaddr_un sun;
 109         int fd;
 110         int ret = 1;
 111
 112         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 113         if (fd < 0) {
 114                 perror("socket");
 115                 goto error;
 116         }
 117
 118         memset(&sun, 0, sizeof(sun));
 119         sun.sun_family = AF_UNIX;
 120         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 121
 122         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 123         if (ret < 0) {
 124                 perror("connect");
 125                 goto error;
 126         }
 127
 128         return fd;
 129
 130 error:
 131         return -1;
 132 }
 133
 134 /*
 135  *      lttcomm_accept_unix_sock
 136  *
 137  *      Do an accept(2) on the sock and return the
 138  *      new file descriptor. The socket MUST be bind(2) before.
 139  */
 140 int lttcomm_accept_unix_sock(int sock)
 141 {
 142         int new_fd;
 143         struct sockaddr_un sun;
 144         socklen_t len = 0;
 145
 146         /* Blocking call */
 147         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 148         if (new_fd < 0) {
 149                 perror("accept");
 150                 goto error;
 151         }
 152
 153         return new_fd;
 154
 155 error:
 156         return -1;
 157 }
 158
 159 /*
 160  *      lttcomm_create_unix_sock
 161  *
 162  *      Creates a AF_UNIX local socket using pathname
 163  *      bind the socket upon creation and return the fd.
 164  */
 165 int lttcomm_create_unix_sock(const char *pathname)
 166 {
 167         struct sockaddr_un sun;
 168         int fd;
 169         int ret = -1;
 170
 171         /* Create server socket */
 172         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 173                 perror("socket");
 174                 goto error;
 175         }
 176
 177         memset(&sun, 0, sizeof(sun));
 178         sun.sun_family = AF_UNIX;
 179         strncpy(sun.sun_path, pathname, strlen(pathname));
 180
 181         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 182         if (ret < 0) {
 183                 perror("bind");
 184                 goto error;
 185         }
 186
 187         return fd;
 188
 189 error:
 190         return ret;
 191 }
 192
 193 /*
 194  *      lttcomm_listen_unix_sock
 195  *
 196  *      Make the socket listen using MAX_LISTEN.
 197  */
 198 int lttcomm_listen_unix_sock(int sock)
 199 {
 200         int ret;
 201
 202         ret = listen(sock, MAX_LISTEN);
 203         if (ret < 0) {
 204                 perror("listen");
 205         }
 206
 207         return ret;
 208 }
 209
 210 /*
 211  *      lttcomm_recv_unix_sock
 212  *
 213  *  Receive data of size len in put that data into
 214  *  the buf param. Using recvmsg API.
 215  *  Return the size of received data.
 216  */
 217 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 218 {
 219         struct msghdr msg;
 220         struct iovec iov[1];
 221         ssize_t ret = -1;
 222
 223         memset(&msg, 0, sizeof(msg));
 224
 225         iov[0].iov_base = buf;
 226         iov[0].iov_len = len;
 227         msg.msg_iov = iov;
 228         msg.msg_iovlen = 1;
 229
 230         ret = recvmsg(sock, &msg, 0);
 231         if (ret < 0) {
 232                 perror("recvmsg");
 233         }
 234
 235         return ret;
 236 }
 237
 238 /*
 239  *      lttcomm_send_unix_sock
 240  *
 241  *      Send buf data of size len. Using sendmsg API.
 242  *      Return the size of sent data.
 243  */
 244 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 245 {
 246         struct msghdr msg;
 247         struct iovec iov[1];
 248         ssize_t ret = -1;
 249
 250         memset(&msg, 0, sizeof(msg));
 251
 252         iov[0].iov_base = buf;
 253         iov[0].iov_len = len;
 254         msg.msg_iov = iov;
 255         msg.msg_iovlen = 1;
 256
 257         ret = sendmsg(sock, &msg, 0);
 258         if (ret < 0) {
 259                 perror("sendmsg");
 260         }
 261
 262         return ret;
 263 }
 264
 265 /*
 266  *  lttcomm_close_unix_sock
 267  *
 268  *  Shutdown cleanly a unix socket.
 269  */
 270 int lttcomm_close_unix_sock(int sock)
 271 {
 272         int ret;
 273
 274         /* Shutdown receptions and transmissions */
 275         ret = shutdown(sock, SHUT_RDWR);
 276         if (ret < 0) {
 277                 perror("shutdown");
 278         }
 279
 280         return ret;
 281 }
 282
 283 /*
 284  *  lttcomm_send_fds_unix_sock
 285  *
 286  *  Send multiple fds on a unix socket.
 287  */
 288 ssize_t lttcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len)
 289 {
 290         struct msghdr msg;
 291         struct cmsghdr *cmptr;
 292         struct iovec iov[1];
 293         ssize_t ret = -1;
 294         unsigned int sizeof_fds = nb_fd * sizeof(int);
 295         char tmp[CMSG_SPACE(sizeof_fds)];
 296
 297         memset(&msg, 0, sizeof(msg));
 298
 299         msg.msg_control = (caddr_t)tmp;
 300         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 301
 302         cmptr = CMSG_FIRSTHDR(&msg);
 303         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 304         cmptr->cmsg_level = SOL_SOCKET;
 305         cmptr->cmsg_type = SCM_RIGHTS;
 306         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 307
 308         iov[0].iov_base = buf;
 309         iov[0].iov_len = len;
 310         msg.msg_iov = iov;
 311         msg.msg_iovlen = 1;
 312
 313         ret = sendmsg(sock, &msg, 0);
 314         if (ret < 0) {
 315                 perror("sendmsg");
 316         }
 317
 318         return ret;
 319 }