tcp.c

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/*
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: c8ca250f513459c54fa7978f6e18c21d3b328173 $
 *
 * @file protocols/radius/packet.c
 * @brief TCP-specific functions.
 *
 * @copyright (C) 2009 Dante http://dante.net
 */
RCSID("$Id: c8ca250f513459c54fa7978f6e18c21d3b328173 $")
 
#include <freeradius-devel/radius/radius.h>
#include <freeradius-devel/util/syserror.h>
#include "tcp.h"
 
fr_packet_t *fr_tcp_recv(int sockfd, int flags)
{
        fr_packet_t *packet = fr_packet_alloc(NULL, false);
 
        if (!packet) return NULL;
 
        packet->socket.fd = sockfd;
 
        if (fr_tcp_read_packet(packet, RADIUS_MAX_ATTRIBUTES, flags) != 1) {
                fr_packet_free(&packet);
                return NULL;
        }
 
        return packet;
}
 
/*
 *      Receives a packet, assuming that the fr_packet_t structure
 *      has been filled out already.
 *
 *      This ASSUMES that the packet is allocated && fields
 *      initialized.
 *
 *      This ASSUMES that the socket is marked as O_NONBLOCK, which
 *      the function above does set, if your system supports it.
 *
 *      Calling this function MAY change sockfd,
 *      if src_ipaddr.af == AF_UNSPEC.
 */
int fr_tcp_read_packet(fr_packet_t *packet, uint32_t max_attributes, bool require_message_authenticator)
{
        ssize_t len;
 
        /*
         *      No data allocated.  Read the 4-byte header into
         *      a temporary buffer.
         */
        if (!packet->data) {
                int packet_len;
 
                len = recv(packet->socket.fd, packet->vector + packet->data_len,
                           4 - packet->data_len, 0);
                if (len == 0) return -2; /* clean close */
 
#ifdef ECONNRESET
                if ((len < 0) && (errno == ECONNRESET)) { /* forced */
                        return -2;
                }
#endif
 
                if (len < 0) {
                        fr_strerror_printf("Error receiving packet: %s", fr_syserror(errno));
                        return -1;
                }
 
                packet->data_len += len;
                if (packet->data_len < 4) { /* want more data */
                        return 0;
                }
 
                packet_len = fr_nbo_to_uint16(packet->vector + 2);
 
                if (packet_len < RADIUS_HEADER_LENGTH) {
                        fr_strerror_const("Discarding packet: Smaller than RFC minimum of 20 bytes");
                        return -1;
                }
 
                /*
                 *      If the packet is too big, then the socket is bad.
                 */
                if (packet_len > MAX_PACKET_LEN) {
                        fr_strerror_const("Discarding packet: Larger than RFC limitation of 4096 bytes");
                        return -1;
                }
 
                packet->data = talloc_array(packet, uint8_t, packet_len);
                if (!packet->data) {
                        fr_strerror_const("Out of memory");
                        return -1;
                }
 
                packet->data_len = packet_len;
                packet->partial = 4;
                memcpy(packet->data, packet->vector, 4);        //-V512
        }
 
        /*
         *      Try to read more data.
         */
        len = recv(packet->socket.fd, packet->data + packet->partial,
                   packet->data_len - packet->partial, 0);
        if (len == 0) return -2; /* clean close */
 
#ifdef ECONNRESET
        if ((len < 0) && (errno == ECONNRESET)) { /* forced */
                return -2;
        }
#endif
 
        if (len < 0) {
                fr_strerror_printf("Error receiving packet: %s", fr_syserror(errno));
                return -1;
        }
 
        packet->partial += len;
 
        if (packet->partial < packet->data_len) {
                return 0;
        }
 
        /*
         *      See if it's a well-formed RADIUS packet.
         */
        if (!fr_packet_ok(packet, max_attributes, require_message_authenticator, NULL)) {
                return -1;
        }
 
        if (fr_debug_lvl) {
                char ip_buf[INET6_ADDRSTRLEN], buffer[256];
 
                if (packet->socket.inet.src_ipaddr.af != AF_UNSPEC) {
                        inet_ntop(packet->socket.inet.src_ipaddr.af, &packet->socket.inet.src_ipaddr.addr, ip_buf, sizeof(ip_buf));
                        snprintf(buffer, sizeof(buffer), "host %s port %d", ip_buf, packet->socket.inet.src_port);
                } else {
                        snprintf(buffer, sizeof(buffer), "socket %d", packet->socket.fd);
                }
 
        }
 
        packet->timestamp = fr_time();
 
        return 1;               /* done reading the packet */
}