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_SESS_NOT_FOUND) ] = "Session name not 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_CHAN_NOT_FOUND) ] = "Kernel channel not found",
  55         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_DISABLE_FAIL) ] = "Disable kernel channel failed",
  56         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_ENABLE_FAIL) ] = "Enable kernel channel failed",
  57         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONTEXT_FAIL) ] = "Add kernel context failed",
  58         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
  59         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
  60         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
  61         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_START_FAIL) ] = "Starting kernel trace failed",
  62         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STOP_FAIL) ] = "Stoping kernel trace failed",
  63         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONSUMER_FAIL) ] = "Kernel consumer start failed",
  64         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STREAM_FAIL) ] = "Kernel create stream failed",
  65         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_FAIL) ] = "Kernel trace directory creation failed",
  66         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_EXIST) ] = "Kernel trace directory already exist",
  67         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
  68         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
  69         [ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
  70         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
  71         [ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
  72         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_ERROR) ] = "Kconsumerd error in polling thread",
  73         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_NVAL) ] = "Kconsumerd polling on closed fd",
  74         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_HUP) ] = "Kconsumerd all fd hung up",
  75         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
  76         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
  77         [ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
  78         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
  79         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
  80         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
  81         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
  82         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
  83 };
  84
  85 /*
  86  *  lttcom_get_readable_code
  87  *
  88  *  Return ptr to string representing a human readable
  89  *  error code from the lttcomm_return_code enum.
  90  *
  91  *  These code MUST be negative in other to treat that
  92  *  as an error value.
  93  */
  94 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  95 {
  96         int tmp_code = -code;
  97
  98         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  99                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
 100         }
 101
 102         return "Unknown error code";
 103 }
 104
 105 /*
 106  *      lttcomm_connect_unix_sock
 107  *
 108  *      Connect to unix socket using the path name.
 109  */
 110 int lttcomm_connect_unix_sock(const char *pathname)
 111 {
 112         struct sockaddr_un sun;
 113         int fd;
 114         int ret = 1;
 115
 116         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 117         if (fd < 0) {
 118                 perror("socket");
 119                 goto error;
 120         }
 121
 122         memset(&sun, 0, sizeof(sun));
 123         sun.sun_family = AF_UNIX;
 124         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 125
 126         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 127         if (ret < 0) {
 128                 perror("connect");
 129                 goto error;
 130         }
 131
 132         return fd;
 133
 134 error:
 135         return -1;
 136 }
 137
 138 /*
 139  *      lttcomm_accept_unix_sock
 140  *
 141  *      Do an accept(2) on the sock and return the
 142  *      new file descriptor. The socket MUST be bind(2) before.
 143  */
 144 int lttcomm_accept_unix_sock(int sock)
 145 {
 146         int new_fd;
 147         struct sockaddr_un sun;
 148         socklen_t len = 0;
 149
 150         /* Blocking call */
 151         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 152         if (new_fd < 0) {
 153                 perror("accept");
 154                 goto error;
 155         }
 156
 157         return new_fd;
 158
 159 error:
 160         return -1;
 161 }
 162
 163 /*
 164  *      lttcomm_create_unix_sock
 165  *
 166  *      Creates a AF_UNIX local socket using pathname
 167  *      bind the socket upon creation and return the fd.
 168  */
 169 int lttcomm_create_unix_sock(const char *pathname)
 170 {
 171         struct sockaddr_un sun;
 172         int fd;
 173         int ret = -1;
 174
 175         /* Create server socket */
 176         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 177                 perror("socket");
 178                 goto error;
 179         }
 180
 181         memset(&sun, 0, sizeof(sun));
 182         sun.sun_family = AF_UNIX;
 183         strncpy(sun.sun_path, pathname, strlen(pathname));
 184
 185         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 186         if (ret < 0) {
 187                 perror("bind");
 188                 goto error;
 189         }
 190
 191         return fd;
 192
 193 error:
 194         return ret;
 195 }
 196
 197 /*
 198  *      lttcomm_listen_unix_sock
 199  *
 200  *      Make the socket listen using MAX_LISTEN.
 201  */
 202 int lttcomm_listen_unix_sock(int sock)
 203 {
 204         int ret;
 205
 206         ret = listen(sock, MAX_LISTEN);
 207         if (ret < 0) {
 208                 perror("listen");
 209         }
 210
 211         return ret;
 212 }
 213
 214 /*
 215  *      lttcomm_recv_unix_sock
 216  *
 217  *  Receive data of size len in put that data into
 218  *  the buf param. Using recvmsg API.
 219  *  Return the size of received data.
 220  */
 221 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 222 {
 223         struct msghdr msg;
 224         struct iovec iov[1];
 225         ssize_t ret = -1;
 226
 227         memset(&msg, 0, sizeof(msg));
 228
 229         iov[0].iov_base = buf;
 230         iov[0].iov_len = len;
 231         msg.msg_iov = iov;
 232         msg.msg_iovlen = 1;
 233
 234         ret = recvmsg(sock, &msg, 0);
 235         if (ret < 0) {
 236                 perror("recvmsg");
 237         }
 238
 239         return ret;
 240 }
 241
 242 /*
 243  *      lttcomm_send_unix_sock
 244  *
 245  *      Send buf data of size len. Using sendmsg API.
 246  *      Return the size of sent data.
 247  */
 248 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 249 {
 250         struct msghdr msg;
 251         struct iovec iov[1];
 252         ssize_t ret = -1;
 253
 254         memset(&msg, 0, sizeof(msg));
 255
 256         iov[0].iov_base = buf;
 257         iov[0].iov_len = len;
 258         msg.msg_iov = iov;
 259         msg.msg_iovlen = 1;
 260
 261         ret = sendmsg(sock, &msg, 0);
 262         if (ret < 0) {
 263                 perror("sendmsg");
 264         }
 265
 266         return ret;
 267 }
 268
 269 /*
 270  *  lttcomm_close_unix_sock
 271  *
 272  *  Shutdown cleanly a unix socket.
 273  */
 274 int lttcomm_close_unix_sock(int sock)
 275 {
 276         int ret;
 277
 278         /* Shutdown receptions and transmissions */
 279         ret = shutdown(sock, SHUT_RDWR);
 280         if (ret < 0) {
 281                 perror("shutdown");
 282         }
 283
 284         return ret;
 285 }
 286
 287 /*
 288  *  lttcomm_send_fds_unix_sock
 289  *
 290  *  Send multiple fds on a unix socket.
 291  */
 292 ssize_t lttcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len)
 293 {
 294         struct msghdr msg;
 295         struct cmsghdr *cmptr;
 296         struct iovec iov[1];
 297         ssize_t ret = -1;
 298         unsigned int sizeof_fds = nb_fd * sizeof(int);
 299         char tmp[CMSG_SPACE(sizeof_fds)];
 300
 301         memset(&msg, 0, sizeof(msg));
 302
 303         msg.msg_control = (caddr_t)tmp;
 304         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 305
 306         cmptr = CMSG_FIRSTHDR(&msg);
 307         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 308         cmptr->cmsg_level = SOL_SOCKET;
 309         cmptr->cmsg_type = SCM_RIGHTS;
 310         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 311
 312         iov[0].iov_base = buf;
 313         iov[0].iov_len = len;
 314         msg.msg_iov = iov;
 315         msg.msg_iovlen = 1;
 316
 317         ret = sendmsg(sock, &msg, 0);
 318         if (ret < 0) {
 319                 perror("sendmsg");
 320         }
 321
 322         return ret;
 323 }