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         if (sock->socket == -1) return rocksock_seterror(sock, RS_ET_OWN, RS_E_NO_SOCKET, ROCKSOCK_FILENAME, __LINE__);
  36 #ifdef USE_SSL
  37         if(sock->ssl && rocksock_ssl_pending(sock)) {
  38                 *result = 1;
  39                 goto no_err;
  40         }
  41 #endif
  42         fd_set readfds;
  43
  44         struct timeval tv;
  45         tv.tv_sec = 0;
  46         tv.tv_usec = 1;
  47         FD_ZERO(&readfds);
  48         FD_SET(sock->socket, &readfds);
  49
  50         readv = select(sock->socket + 1, &readfds, 0, 0, &tv);
  51         if(readv < 0) return rocksock_seterror(sock, RS_ET_SYS, errno, ROCKSOCK_FILENAME, __LINE__);
  52         *result = FD_ISSET(sock->socket, &readfds);
  53 #ifdef USE_SSL
  54         if(sock->ssl && *result) {
  55                 return rocksock_ssl_peek(sock, result);
  56         }
  57         no_err:
  58 #endif
  59         return rocksock_seterror(sock, RS_ET_OWN, 0, NULL, 0);
  60 }