src/lib/tcp.c

   1 /*
   2  * tcp.c        TCP-specific functions.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright (C) 2009 Dante http://dante.net
  21  */
  22
  23 RCSID("$Id$")
  24
  25 #include        <freeradius-devel/libradius.h>
  26
  27 #ifdef WITH_TCP
  28
  29 RADIUS_PACKET *fr_tcp_recv(int sockfd, int flags)
  30 {
  31         RADIUS_PACKET *packet = rad_alloc(NULL, false);
  32
  33         if (!packet) return NULL;
  34
  35         packet->sockfd = sockfd;
  36
  37         if (fr_tcp_read_packet(packet, flags) != 1) {
  38                 rad_free(&packet);
  39                 return NULL;
  40         }
  41
  42         return packet;
  43 }
  44
  45
  46 /*
  47  *      Receives a packet, assuming that the RADIUS_PACKET structure
  48  *      has been filled out already.
  49  *
  50  *      This ASSUMES that the packet is allocated && fields
  51  *      initialized.
  52  *
  53  *      This ASSUMES that the socket is marked as O_NONBLOCK, which
  54  *      the function above does set, if your system supports it.
  55  *
  56  *      Calling this function MAY change sockfd,
  57  *      if src_ipaddr.af == AF_UNSPEC.
  58  */
  59 int fr_tcp_read_packet(RADIUS_PACKET *packet, int flags)
  60 {
  61         ssize_t len;
  62
  63         /*
  64          *      No data allocated.  Read the 4-byte header into
  65          *      a temporary buffer.
  66          */
  67         if (!packet->data) {
  68                 int packet_len;
  69
  70                 len = recv(packet->sockfd, packet->vector + packet->data_len,
  71                            4 - packet->data_len, 0);
  72                 if (len == 0) return -2; /* clean close */
  73
  74 #ifdef ECONNRESET
  75                 if ((len < 0) && (errno == ECONNRESET)) { /* forced */
  76                         return -2;
  77                 }
  78 #endif
  79
  80                 if (len < 0) {
  81                         fr_strerror_printf("Error receiving packet: %s",
  82                                    fr_syserror(errno));
  83                         return -1;
  84                 }
  85
  86                 packet->data_len += len;
  87                 if (packet->data_len < 4) { /* want more data */
  88                         return 0;
  89                 }
  90
  91                 packet_len = (packet->vector[2] << 8) | packet->vector[3];
  92
  93                 if (packet_len < RADIUS_HDR_LEN) {
  94                         fr_strerror_printf("Discarding packet: Smaller than RFC minimum of 20 bytes");
  95                         return -1;
  96                 }
  97
  98                 /*
  99                  *      If the packet is too big, then the socket is bad.
 100                  */
 101                 if (packet_len > MAX_PACKET_LEN) {
 102                         fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes");
 103                         return -1;
 104                 }
 105
 106                 packet->data = talloc_array(packet, uint8_t, packet_len);
 107                 if (!packet->data) {
 108                         fr_strerror_printf("Out of memory");
 109                         return -1;
 110                 }
 111
 112                 packet->data_len = packet_len;
 113                 packet->partial = 4;
 114                 memcpy(packet->data, packet->vector, 4);
 115         }
 116
 117         /*
 118          *      Try to read more data.
 119          */
 120         len = recv(packet->sockfd, packet->data + packet->partial,
 121                    packet->data_len - packet->partial, 0);
 122         if (len == 0) return -2; /* clean close */
 123
 124 #ifdef ECONNRESET
 125         if ((len < 0) && (errno == ECONNRESET)) { /* forced */
 126                 return -2;
 127         }
 128 #endif
 129
 130         if (len < 0) {
 131                 fr_strerror_printf("Error receiving packet: %s", fr_syserror(errno));
 132                 return -1;
 133         }
 134
 135         packet->partial += len;
 136
 137         if (packet->partial < packet->data_len) {
 138                 return 0;
 139         }
 140
 141         /*
 142          *      See if it's a well-formed RADIUS packet.
 143          */
 144         if (!rad_packet_ok(packet, flags, NULL)) {
 145                 return -1;
 146         }
 147
 148         /*
 149          *      Explicitly set the VP list to empty.
 150          */
 151         packet->vps = NULL;
 152
 153         if (fr_debug_lvl) {
 154                 char ip_buf[128], buffer[256];
 155
 156                 if (packet->src_ipaddr.af != AF_UNSPEC) {
 157                         inet_ntop(packet->src_ipaddr.af,
 158                                   &packet->src_ipaddr.ipaddr,
 159                                   ip_buf, sizeof(ip_buf));
 160                         snprintf(buffer, sizeof(buffer), "host %s port %d",
 161                                  ip_buf, packet->src_port);
 162                 } else {
 163                         snprintf(buffer, sizeof(buffer), "socket %d",
 164                                  packet->sockfd);
 165                 }
 166
 167         }
 168
 169         return 1;               /* done reading the packet */
 170 }
 171
 172 #endif /* WITH_TCP */