rocksock_peek.c

   1 /*
   2  * author: rofl0r (C) 2011-2013
   3  * License: LGPL 2.1+ with static linking exception
   4  */
   5
   6 #undef _POSIX_C_SOURCE
   7 #define _POSIX_C_SOURCE 200809L
   8 #undef _GNU_SOURCE
   9 #define _GNU_SOURCE
  10
  11 #include <stdio.h>
  12 #include <sys/select.h>
  13 #include <netinet/in.h>
  14 #include <errno.h>
  15
  16 #include "rocksock.h"
  17 #include "rocksock_internal.h"
  18 #ifdef USE_SSL
  19 #include "rocksock_ssl_internal.h"
  20 #endif
  21
  22 #ifndef ROCKSOCK_FILENAME
  23 #define ROCKSOCK_FILENAME __FILE__
  24 #endif
  25
  26 /*
  27    return value: error code or 0 for no error
  28    result will contain 0 if no data is available, 1 if data is available.
  29    if data is available, and a subsequent recv call returns 0 bytes read, the
  30    connection was terminated. */
  31 int rocksock_peek(rocksock* sock, int *result) {
  32         ssize_t readv;
  33         if(!result)
  34                 return rocksock_seterror(sock, RS_ET_OWN, RS_E_NULL, ROCKSOCK_FILENAME, __LINE__);
  35 #ifdef USE_SSL
  36         if(sock->ssl && rocksock_ssl_pending(sock)) {
  37                 *result = 1;
  38                 goto no_err;
  39         }
  40 #endif
  41         fd_set readfds;
  42
  43         struct timeval tv;
  44         tv.tv_sec = 0;
  45         tv.tv_usec = 1;
  46         FD_ZERO(&readfds);
  47         FD_SET(sock->socket, &readfds);
  48
  49         readv = select(sock->socket + 1, &readfds, 0, 0, &tv);
  50         if(readv < 0) return rocksock_seterror(sock, RS_ET_SYS, errno, ROCKSOCK_FILENAME, __LINE__);
  51         *result = FD_ISSET(sock->socket, &readfds);
  52 #ifdef USE_SSL
  53         if(sock->ssl && *result) {
  54                 return rocksock_ssl_peek(sock, result);
  55         }
  56         no_err:
  57 #endif
  58         return rocksock_seterror(sock, RS_ET_NO_ERROR, 0, NULL, 0);
  59 }