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 /* FIXME: into common RADIUS header? */
  30 #define MAX_PACKET_LEN 4096
  31
  32 /*
  33  *      Open a socket TO the given IP and port.
  34  */
  35 int fr_tcp_client_socket(fr_ipaddr_t *src_ipaddr,
  36                          fr_ipaddr_t *dst_ipaddr, uint16_t dst_port)
  37 {
  38         int sockfd;
  39         struct sockaddr_storage salocal;
  40         socklen_t       salen;
  41
  42         if (!dst_ipaddr) return -1;
  43
  44         sockfd = socket(dst_ipaddr->af, SOCK_STREAM, 0);
  45         if (sockfd < 0) {
  46                 return sockfd;
  47         }
  48
  49         /*
  50          *      Allow the caller to bind us to a specific source IP.
  51          */
  52         if (src_ipaddr && (src_ipaddr->af != AF_UNSPEC)) {
  53                 if (!fr_ipaddr2sockaddr(src_ipaddr, 0, &salocal, &salen)) {
  54                         close(sockfd);
  55                         return -1;
  56                 }
  57
  58                 if (bind(sockfd, (struct sockaddr *) &salocal, salen) < 0) {
  59                         fr_strerror_printf("Failure binding to IP: %s",
  60                                            fr_syserror(errno));
  61                         close(sockfd);
  62                         return -1;
  63                 }
  64         }
  65
  66         if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &salocal, &salen)) {
  67                 close(sockfd);
  68                 return -1;
  69         }
  70
  71         /*
  72          *      FIXME: If EINPROGRESS, then tell the caller that
  73          *      somehow.  The caller can then call connect() when the
  74          *      socket is ready...
  75          */
  76         if (connect(sockfd, (struct sockaddr *) &salocal, salen) < 0) {
  77                 fr_strerror_printf("Failed in connect(): %s", fr_syserror(errno));
  78                 close(sockfd);
  79                 return -1;
  80         }
  81
  82         /*
  83          *      Set non-block *AFTER* connecting to the remote server
  84          *      so it doesn't return immediately.
  85          */
  86         if (fr_nonblock(sockfd) < 0) {
  87                 close(sockfd);
  88                 return -1;
  89         }
  90
  91         return sockfd;
  92 }
  93
  94
  95 RADIUS_PACKET *fr_tcp_recv(int sockfd, int flags)
  96 {
  97         RADIUS_PACKET *packet = rad_alloc(NULL, 0);
  98
  99         if (!packet) return NULL;
 100
 101         packet->sockfd = sockfd;
 102
 103         if (fr_tcp_read_packet(packet, flags) != 1) {
 104                 rad_free(&packet);
 105                 return NULL;
 106         }
 107
 108         return packet;
 109 }
 110
 111
 112 /*
 113  *      Receives a packet, assuming that the RADIUS_PACKET structure
 114  *      has been filled out already.
 115  *
 116  *      This ASSUMES that the packet is allocated && fields
 117  *      initialized.
 118  *
 119  *      This ASSUMES that the socket is marked as O_NONBLOCK, which
 120  *      the function above does set, if your system supports it.
 121  *
 122  *      Calling this function MAY change sockfd,
 123  *      if src_ipaddr.af == AF_UNSPEC.
 124  */
 125 int fr_tcp_read_packet(RADIUS_PACKET *packet, int flags)
 126 {
 127         ssize_t len;
 128
 129         /*
 130          *      No data allocated.  Read the 4-byte header into
 131          *      a temporary buffer.
 132          */
 133         if (!packet->data) {
 134                 int packet_len;
 135
 136                 len = recv(packet->sockfd, packet->vector + packet->data_len,
 137                            4 - packet->data_len, 0);
 138                 if (len == 0) return -2; /* clean close */
 139
 140 #ifdef ECONNRESET
 141                 if ((len < 0) && (errno == ECONNRESET)) { /* forced */
 142                         return -2;
 143                 }
 144 #endif
 145
 146                 if (len < 0) {
 147                         fr_strerror_printf("Error receiving packet: %s",
 148                                    fr_syserror(errno));
 149                         return -1;
 150                 }
 151
 152                 packet->data_len += len;
 153                 if (packet->data_len < 4) { /* want more data */
 154                         return 0;
 155                 }
 156
 157                 packet_len = (packet->vector[2] << 8) | packet->vector[3];
 158
 159                 if (packet_len < AUTH_HDR_LEN) {
 160                         fr_strerror_printf("Discarding packet: Smaller than RFC minimum of 20 bytes");
 161                         return -1;
 162                 }
 163
 164                 /*
 165                  *      If the packet is too big, then the socket is bad.
 166                  */
 167                 if (packet_len > MAX_PACKET_LEN) {
 168                         fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes");
 169                         return -1;
 170                 }
 171
 172                 packet->data = talloc_array(packet, uint8_t, packet_len);
 173                 if (!packet->data) {
 174                         fr_strerror_printf("Out of memory");
 175                         return -1;
 176                 }
 177
 178                 packet->data_len = packet_len;
 179                 packet->partial = 4;
 180                 memcpy(packet->data, packet->vector, 4);
 181         }
 182
 183         /*
 184          *      Try to read more data.
 185          */
 186         len = recv(packet->sockfd, packet->data + packet->partial,
 187                    packet->data_len - packet->partial, 0);
 188         if (len == 0) return -2; /* clean close */
 189
 190 #ifdef ECONNRESET
 191         if ((len < 0) && (errno == ECONNRESET)) { /* forced */
 192                 return -2;
 193         }
 194 #endif
 195
 196         if (len < 0) {
 197                 fr_strerror_printf("Error receiving packet: %s", fr_syserror(errno));
 198                 return -1;
 199         }
 200
 201         packet->partial += len;
 202
 203         if (packet->partial < packet->data_len) {
 204                 return 0;
 205         }
 206
 207         /*
 208          *      See if it's a well-formed RADIUS packet.
 209          */
 210         if (!rad_packet_ok(packet, flags, NULL)) {
 211                 return -1;
 212         }
 213
 214         /*
 215          *      Explicitly set the VP list to empty.
 216          */
 217         packet->vps = NULL;
 218
 219         if (fr_debug_flag) {
 220                 char ip_buf[128], buffer[256];
 221
 222                 if (packet->src_ipaddr.af != AF_UNSPEC) {
 223                         inet_ntop(packet->src_ipaddr.af,
 224                                   &packet->src_ipaddr.ipaddr,
 225                                   ip_buf, sizeof(ip_buf));
 226                         snprintf(buffer, sizeof(buffer), "host %s port %d",
 227                                  ip_buf, packet->src_port);
 228                 } else {
 229                         snprintf(buffer, sizeof(buffer), "socket %d",
 230                                  packet->sockfd);
 231                 }
 232
 233
 234                 if (is_radius_code(packet->code)) {
 235                         DEBUG("Received %s packet from %s",
 236                               fr_packet_codes[packet->code], buffer);
 237                 } else {
 238                         DEBUG("Received packet from %s code %d",
 239                               buffer, packet->code);
 240                 }
 241                 DEBUG(", id=%d, length=%zu\n", packet->id, packet->data_len);
 242         }
 243
 244         return 1;               /* done reading the packet */
 245 }
 246
 247 #endif /* WITH_TCP */