+++ /dev/null
-/*
- net_packet.c -- Handles in- and outgoing VPN packets
- Copyright (C) 1998-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
- 2000-2002 Guus Sliepen <guus@sliepen.warande.net>
-
- 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., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Id: net_packet.c,v 1.1 2002/04/28 12:46:26 zarq Exp $
-*/
-
-#include "config.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#ifdef HAVE_LINUX
- #include <netinet/ip.h>
- #include <netinet/tcp.h>
-#endif
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <signal.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <sys/ioctl.h>
-/* SunOS really wants sys/socket.h BEFORE net/if.h,
- and FreeBSD wants these lines below the rest. */
-#include <arpa/inet.h>
-#include <sys/socket.h>
-#include <net/if.h>
-
-#include <openssl/rand.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-#include <openssl/hmac.h>
-
-#ifndef HAVE_RAND_PSEUDO_BYTES
-#define RAND_pseudo_bytes RAND_bytes
-#endif
-
-#include <zlib.h>
-
-#include <utils.h>
-#include <xalloc.h>
-#include <avl_tree.h>
-#include <list.h>
-
-#include "conf.h"
-#include "connection.h"
-#include "meta.h"
-#include "net.h"
-#include "netutl.h"
-#include "process.h"
-#include "protocol.h"
-#include "subnet.h"
-#include "graph.h"
-#include "process.h"
-#include "route.h"
-#include "device.h"
-#include "event.h"
-#include "logging.h"
-
-#include "system.h"
-
-int keylifetime = 0;
-int keyexpires = 0;
-
-#define MAX_SEQNO 1073741824
-
-/* VPN packet I/O */
-
-void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
-{
- vpn_packet_t pkt1, pkt2;
- vpn_packet_t *pkt[] = {&pkt1, &pkt2, &pkt1, &pkt2};
- int nextpkt = 0;
- vpn_packet_t *outpkt = pkt[0];
- int outlen, outpad;
- long int complen = MTU + 12;
- EVP_CIPHER_CTX ctx;
- char hmac[EVP_MAX_MD_SIZE];
-cp
- /* Check the message authentication code */
-
- if(myself->digest && myself->maclength)
- {
- inpkt->len -= myself->maclength;
- HMAC(myself->digest, myself->key, myself->keylength, (char *)&inpkt->seqno, inpkt->len, hmac, NULL);
- if(memcmp(hmac, (char *)&inpkt->seqno + inpkt->len, myself->maclength))
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), n->name, n->hostname);
- return;
- }
- }
-
- /* Decrypt the packet */
-
- if(myself->cipher)
- {
- outpkt = pkt[nextpkt++];
-
- EVP_DecryptInit(&ctx, myself->cipher, myself->key, myself->key + myself->cipher->key_len);
- EVP_DecryptUpdate(&ctx, (char *)&outpkt->seqno, &outlen, (char *)&inpkt->seqno, inpkt->len);
- EVP_DecryptFinal(&ctx, (char *)&outpkt->seqno + outlen, &outpad);
-
- outpkt->len = outlen + outpad;
- inpkt = outpkt;
- }
-
- /* Check the sequence number */
-
- inpkt->len -= sizeof(inpkt->seqno);
- inpkt->seqno = ntohl(inpkt->seqno);
-
- if(inpkt->seqno <= n->received_seqno)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_DEBUG, _("Got late or replayed packet from %s (%s), seqno %d"), n->name, n->hostname, inpkt->seqno);
- return;
- }
-
- n->received_seqno = inpkt->seqno;
-
- if(n->received_seqno > MAX_SEQNO)
- keyexpires = 0;
-
- /* Decompress the packet */
-
- if(myself->compression)
- {
- outpkt = pkt[nextpkt++];
-
- if(uncompress(outpkt->data, &complen, inpkt->data, inpkt->len) != Z_OK)
- {
- syslog(LOG_ERR, _("Error while uncompressing packet from %s (%s)"), n->name, n->hostname);
- return;
- }
-
- outpkt->len = complen;
- inpkt = outpkt;
- }
-
- receive_packet(n, inpkt);
-cp
-}
-
-void receive_tcppacket(connection_t *c, char *buffer, int len)
-{
- vpn_packet_t outpkt;
-cp
- outpkt.len = len;
- memcpy(outpkt.data, buffer, len);
-
- receive_packet(c->node, &outpkt);
-cp
-}
-
-void receive_packet(node_t *n, vpn_packet_t *packet)
-{
-cp
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, n->name, n->hostname);
-cp
-}
-
-void send_udppacket(node_t *n, vpn_packet_t *inpkt)
-{
- vpn_packet_t pkt1, pkt2;
- vpn_packet_t *pkt[] = {&pkt1, &pkt2, &pkt1, &pkt2};
- int nextpkt = 0;
- vpn_packet_t *outpkt;
- int origlen;
- int outlen, outpad;
- long int complen = MTU + 12;
- EVP_CIPHER_CTX ctx;
- vpn_packet_t *copy;
- static int priority = 0;
- int origpriority;
- int sock;
-cp
- /* Make sure we have a valid key */
-
- if(!n->status.validkey)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
- n->name, n->hostname);
-
- /* Since packet is on the stack of handle_tap_input(),
- we have to make a copy of it first. */
-
- copy = xmalloc(sizeof(vpn_packet_t));
- memcpy(copy, inpkt, sizeof(vpn_packet_t));
-
- list_insert_tail(n->queue, copy);
-
- if(n->queue->count > MAXQUEUELENGTH)
- list_delete_head(n->queue);
-
- if(!n->status.waitingforkey)
- send_req_key(n->nexthop->connection, myself, n);
-
- n->status.waitingforkey = 1;
-
- return;
- }
-
- origlen = inpkt->len;
- origpriority = inpkt->priority;
-
- /* Compress the packet */
-
- if(n->compression)
- {
- outpkt = pkt[nextpkt++];
-
- if(compress2(outpkt->data, &complen, inpkt->data, inpkt->len, n->compression) != Z_OK)
- {
- syslog(LOG_ERR, _("Error while compressing packet to %s (%s)"), n->name, n->hostname);
- return;
- }
-
- outpkt->len = complen;
- inpkt = outpkt;
- }
-
- /* Add sequence number */
-
- inpkt->seqno = htonl(++(n->sent_seqno));
- inpkt->len += sizeof(inpkt->seqno);
-
- /* Encrypt the packet */
-
- if(n->cipher)
- {
- outpkt = pkt[nextpkt++];
-
- EVP_EncryptInit(&ctx, n->cipher, n->key, n->key + n->cipher->key_len);
- EVP_EncryptUpdate(&ctx, (char *)&outpkt->seqno, &outlen, (char *)&inpkt->seqno, inpkt->len);
- EVP_EncryptFinal(&ctx, (char *)&outpkt->seqno + outlen, &outpad);
-
- outpkt->len = outlen + outpad;
- inpkt = outpkt;
- }
-
- /* Add the message authentication code */
-
- if(n->digest && n->maclength)
- {
- HMAC(n->digest, n->key, n->keylength, (char *)&inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len, &outlen);
- inpkt->len += n->maclength;
- }
-
- /* Determine which socket we have to use */
-
- for(sock = 0; sock < listen_sockets; sock++)
- if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family)
- break;
-
- if(sock >= listen_sockets)
- sock = 0; /* If none is available, just use the first and hope for the best. */
-
- /* Send the packet */
-
-#if defined(SOL_IP) && defined(IP_TOS)
- if(priorityinheritance && origpriority != priority && listen_socket[sock].sa.sa.sa_family == AF_INET)
- {
- priority = origpriority;
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_DEBUG, _("Setting outgoing packet priority to %d"), priority);
- if(setsockopt(sock, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
- syslog(LOG_ERR, _("System call `%s' failed: %s"), "setsockopt", strerror(errno));
- }
-#endif
-
- if((sendto(listen_socket[sock].udp, (char *)&inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0)
- {
- syslog(LOG_ERR, _("Error sending packet to %s (%s): %s"),
- n->name, n->hostname, strerror(errno));
- return;
- }
-
- inpkt->len = origlen;
-cp
-}
-
-/*
- send a packet to the given vpn ip.
-*/
-void send_packet(node_t *n, vpn_packet_t *packet)
-{
- node_t *via;
-cp
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
- packet->len, n->name, n->hostname);
-
- if(n == myself)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- {
- syslog(LOG_NOTICE, _("Packet is looping back to us!"));
- }
-
- return;
- }
-
- if(!n->status.reachable)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("Node %s (%s) is not reachable"),
- n->name, n->hostname);
- return;
- }
-
- via = (n->via == myself)?n->nexthop:n->via;
-
- if(via != n && debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_ERR, _("Sending packet to %s via %s (%s)"),
- n->name, via->name, n->via->hostname);
-
- if((myself->options | via->options) & OPTION_TCPONLY)
- {
- if(send_tcppacket(via->connection, packet))
- terminate_connection(via->connection, 1);
- }
- else
- send_udppacket(via, packet);
-}
-
-/* Broadcast a packet using the minimum spanning tree */
-
-void broadcast_packet(node_t *from, vpn_packet_t *packet)
-{
- avl_node_t *node;
- connection_t *c;
-cp
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
- packet->len, from->name, from->hostname);
-
- for(node = connection_tree->head; node; node = node->next)
- {
- c = (connection_t *)node->data;
- if(c->status.active && c->status.mst && c != from->nexthop->connection)
- send_packet(c->node, packet);
- }
-cp
-}
-
-void flush_queue(node_t *n)
-{
- list_node_t *node, *next;
-cp
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("Flushing queue for %s (%s)"), n->name, n->hostname);
-
- for(node = n->queue->head; node; node = next)
- {
- next = node->next;
- send_udppacket(n, (vpn_packet_t *)node->data);
- list_delete_node(n->queue, node);
- }
-cp
-}
-
-void handle_incoming_vpn_data(int sock)
-{
- vpn_packet_t pkt;
- int x, l = sizeof(x);
- char *hostname;
- sockaddr_t from;
- socklen_t fromlen = sizeof(from);
- node_t *n;
-cp
- if(getsockopt(sock, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
- {
- syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%s"),
- __FILE__, __LINE__, sock, strerror(errno));
- cp_trace();
- exit(1);
- }
- if(x)
- {
- syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
- return;
- }
-
- if((pkt.len = recvfrom(sock, (char *)&pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen)) <= 0)
- {
- syslog(LOG_ERR, _("Receiving packet failed: %s"), strerror(errno));
- return;
- }
-
- sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
-
- n = lookup_node_udp(&from);
-
- if(!n)
- {
- hostname = sockaddr2hostname(&from);
- syslog(LOG_WARNING, _("Received UDP packet from unknown source %s"), hostname);
- free(hostname);
- return;
- }
-
- if(n->connection)
- n->connection->last_ping_time = now;
-
- receive_udppacket(n, &pkt);
-cp
-}
-
projects / tinc / blobdiff