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_ENABLE_FAIL) ] = "Enable kernel channel failed",
  56         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
  57         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
  58         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
  59         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_START_FAIL) ] = "Starting kernel trace failed",
  60         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STOP_FAIL) ] = "Stoping kernel trace failed",
  61         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONSUMER_FAIL) ] = "Kernel consumer start failed",
  62         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STREAM_FAIL) ] = "Kernel create stream failed",
  63         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_FAIL) ] = "Kernel trace directory creation failed",
  64         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_EXIST) ] = "Kernel trace directory already exist",
  65         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
  66         [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
  67         [ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
  68         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
  69         [ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
  70         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_ERROR) ] = "Kconsumerd error in polling thread",
  71         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_NVAL) ] = "Kconsumerd polling on closed fd",
  72         [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_HUP) ] = "Kconsumerd all fd hung up",
  73         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
  74         [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
  75         [ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
  76         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
  77         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
  78         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
  79         [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
  80         [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "No event found",
  81 };
  82
  83 /*
  84  *  lttcom_get_readable_code
  85  *
  86  *  Return ptr to string representing a human readable
  87  *  error code from the lttcomm_return_code enum.
  88  *
  89  *  These code MUST be negative in other to treat that
  90  *  as an error value.
  91  */
  92 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
  93 {
  94         int tmp_code = -code;
  95
  96         if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
  97                 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
  98         }
  99
 100         return "Unknown error code";
 101 }
 102
 103 /*
 104  *      lttcomm_connect_unix_sock
 105  *
 106  *      Connect to unix socket using the path name.
 107  */
 108 int lttcomm_connect_unix_sock(const char *pathname)
 109 {
 110         struct sockaddr_un sun;
 111         int fd;
 112         int ret = 1;
 113
 114         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 115         if (fd < 0) {
 116                 perror("socket");
 117                 goto error;
 118         }
 119
 120         memset(&sun, 0, sizeof(sun));
 121         sun.sun_family = AF_UNIX;
 122         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 123
 124         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 125         if (ret < 0) {
 126                 perror("connect");
 127                 goto error;
 128         }
 129
 130         return fd;
 131
 132 error:
 133         return -1;
 134 }
 135
 136 /*
 137  *      lttcomm_accept_unix_sock
 138  *
 139  *      Do an accept(2) on the sock and return the
 140  *      new file descriptor. The socket MUST be bind(2) before.
 141  */
 142 int lttcomm_accept_unix_sock(int sock)
 143 {
 144         int new_fd;
 145         struct sockaddr_un sun;
 146         socklen_t len = 0;
 147
 148         /* Blocking call */
 149         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 150         if (new_fd < 0) {
 151                 perror("accept");
 152                 goto error;
 153         }
 154
 155         return new_fd;
 156
 157 error:
 158         return -1;
 159 }
 160
 161 /*
 162  *      lttcomm_create_unix_sock
 163  *
 164  *      Creates a AF_UNIX local socket using pathname
 165  *      bind the socket upon creation and return the fd.
 166  */
 167 int lttcomm_create_unix_sock(const char *pathname)
 168 {
 169         struct sockaddr_un sun;
 170         int fd;
 171         int ret = -1;
 172
 173         /* Create server socket */
 174         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 175                 perror("socket");
 176                 goto error;
 177         }
 178
 179         memset(&sun, 0, sizeof(sun));
 180         sun.sun_family = AF_UNIX;
 181         strncpy(sun.sun_path, pathname, strlen(pathname));
 182
 183         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 184         if (ret < 0) {
 185                 perror("bind");
 186                 goto error;
 187         }
 188
 189         return fd;
 190
 191 error:
 192         return ret;
 193 }
 194
 195 /*
 196  *      lttcomm_listen_unix_sock
 197  *
 198  *      Make the socket listen using MAX_LISTEN.
 199  */
 200 int lttcomm_listen_unix_sock(int sock)
 201 {
 202         int ret;
 203
 204         ret = listen(sock, MAX_LISTEN);
 205         if (ret < 0) {
 206                 perror("listen");
 207         }
 208
 209         return ret;
 210 }
 211
 212 /*
 213  *      lttcomm_recv_unix_sock
 214  *
 215  *  Receive data of size len in put that data into
 216  *  the buf param. Using recvmsg API.
 217  *  Return the size of received data.
 218  */
 219 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 220 {
 221         struct msghdr msg;
 222         struct iovec iov[1];
 223         ssize_t ret = -1;
 224
 225         memset(&msg, 0, sizeof(msg));
 226
 227         iov[0].iov_base = buf;
 228         iov[0].iov_len = len;
 229         msg.msg_iov = iov;
 230         msg.msg_iovlen = 1;
 231
 232         ret = recvmsg(sock, &msg, 0);
 233         if (ret < 0) {
 234                 perror("recvmsg");
 235         }
 236
 237         return ret;
 238 }
 239
 240 /*
 241  *      lttcomm_send_unix_sock
 242  *
 243  *      Send buf data of size len. Using sendmsg API.
 244  *      Return the size of sent data.
 245  */
 246 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
 247 {
 248         struct msghdr msg;
 249         struct iovec iov[1];
 250         ssize_t ret = -1;
 251
 252         memset(&msg, 0, sizeof(msg));
 253
 254         iov[0].iov_base = buf;
 255         iov[0].iov_len = len;
 256         msg.msg_iov = iov;
 257         msg.msg_iovlen = 1;
 258
 259         ret = sendmsg(sock, &msg, 0);
 260         if (ret < 0) {
 261                 perror("sendmsg");
 262         }
 263
 264         return ret;
 265 }
 266
 267 /*
 268  *  lttcomm_close_unix_sock
 269  *
 270  *  Shutdown cleanly a unix socket.
 271  */
 272 int lttcomm_close_unix_sock(int sock)
 273 {
 274         int ret;
 275
 276         /* Shutdown receptions and transmissions */
 277         ret = shutdown(sock, SHUT_RDWR);
 278         if (ret < 0) {
 279                 perror("shutdown");
 280         }
 281
 282         return ret;
 283 }
 284
 285 /*
 286  *  lttcomm_send_fds_unix_sock
 287  *
 288  *  Send multiple fds on a unix socket.
 289  */
 290 ssize_t lttcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len)
 291 {
 292         struct msghdr msg;
 293         struct cmsghdr *cmptr;
 294         struct iovec iov[1];
 295         ssize_t ret = -1;
 296         unsigned int sizeof_fds = nb_fd * sizeof(int);
 297         char tmp[CMSG_SPACE(sizeof_fds)];
 298
 299         memset(&msg, 0, sizeof(msg));
 300
 301         msg.msg_control = (caddr_t)tmp;
 302         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 303
 304         cmptr = CMSG_FIRSTHDR(&msg);
 305         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 306         cmptr->cmsg_level = SOL_SOCKET;
 307         cmptr->cmsg_type = SCM_RIGHTS;
 308         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 309
 310         iov[0].iov_base = buf;
 311         iov[0].iov_len = len;
 312         msg.msg_iov = iov;
 313         msg.msg_iovlen = 1;
 314
 315         ret = sendmsg(sock, &msg, 0);
 316         if (ret < 0) {
 317                 perror("sendmsg");
 318         }
 319
 320         return ret;
 321 }