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Copy structs from packets to the stack before using them, to prevent

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alignment issues.
This commit is contained in:
Guus Sliepen 2003-10-06 13:49:57 +00:00
parent acbb9d6692
commit 60943122f7
1 changed files with 174 additions and 133 deletions
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307
src/route.c
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@ -17,7 +17,7 @@
along with this program; if not, write to the Free Software along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
$Id: route.c,v 1.1.2.66 2003/10/01 09:14:01 guus Exp $ $Id: route.c,v 1.1.2.67 2003/10/06 13:49:57 guus Exp $
*/ */
#include "system.h" #include "system.h"
@ -57,6 +57,17 @@ int macexpire = 600;
bool overwrite_mac = false; bool overwrite_mac = false;
mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}}; mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}};
/* Sizes of various headers */
static size_t ether_size = sizeof(struct ether_header);
static size_t arp_size = sizeof(struct ether_arp);
static size_t ip_size = sizeof(struct ip);
static size_t icmp_size = sizeof(struct icmp) - sizeof(struct ip);
static size_t ip6_size = sizeof(struct ip6_hdr);
static size_t icmp6_size = sizeof(struct icmp6_hdr);
static size_t ns_size = sizeof(struct nd_neighbor_solicit);
static size_t opt_size = sizeof(struct nd_opt_hdr);
/* RFC 1071 */ /* RFC 1071 */
static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) static uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
@ -78,13 +89,18 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
return ~checksum; return ~checksum;
} }
static bool ratelimit(void) { static bool ratelimit(int frequency) {
static time_t lasttime = 0; static time_t lasttime = 0;
static int count = 0;
if(lasttime == now) if(lasttime == now) {
return true; if(++count > frequency)
return true;
} else {
lasttime = now;
count = 0;
}
lasttime = now;
return false; return false;
} }
@ -174,59 +190,68 @@ static node_t *route_mac(vpn_packet_t *packet)
static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code) static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
{ {
struct ip *hdr; struct ip ip;
struct icmp *icmp; struct icmp icmp;
struct in_addr ip_src; struct in_addr ip_src;
struct in_addr ip_dst; struct in_addr ip_dst;
uint32_t oldlen; uint32_t oldlen;
if(ratelimit()) if(ratelimit(3))
return; return;
cp(); cp();
hdr = (struct ip *)(packet->data + 14); /* Copy headers from packet into properly aligned structs on the stack */
icmp = (struct icmp *)(packet->data + 14 + 20);
memcpy(&ip, packet->data + ether_size, ip_size);
memcpy(&icmp, packet->data + ether_size + ip_size, icmp_size);
/* Remember original source and destination */ /* Remember original source and destination */
memcpy(&ip_src, &hdr->ip_src, 4); memcpy(&ip_src, &ip.ip_src, sizeof(ip_src));
memcpy(&ip_dst, &hdr->ip_dst, 4); memcpy(&ip_dst, &ip.ip_dst, sizeof(ip_dst));
oldlen = packet->len - 14;
oldlen = packet->len - ether_size;
if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(*icmp)) if(oldlen >= IP_MSS - ip_size - icmp_size)
oldlen = IP_MSS - sizeof(*hdr) - sizeof(*icmp); oldlen = IP_MSS - ip_size - icmp_size;
/* Copy first part of original contents to ICMP message */ /* Copy first part of original contents to ICMP message */
memmove(&icmp->icmp_ip, hdr, oldlen); memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
/* Fill in IPv4 header */ /* Fill in IPv4 header */
hdr->ip_v = 4; ip.ip_v = 4;
hdr->ip_hl = sizeof(*hdr) / 4; ip.ip_hl = ip_size / 4;
hdr->ip_tos = 0; ip.ip_tos = 0;
hdr->ip_len = htons(20 + 8 + oldlen); ip.ip_len = htons(ip_size + icmp_size + oldlen);
hdr->ip_id = 0; ip.ip_id = 0;
hdr->ip_off = 0; ip.ip_off = 0;
hdr->ip_ttl = 255; ip.ip_ttl = 255;
hdr->ip_p = IPPROTO_ICMP; ip.ip_p = IPPROTO_ICMP;
hdr->ip_sum = 0; ip.ip_sum = 0;
memcpy(&hdr->ip_src, &ip_dst, 4); memcpy(&ip.ip_src, &ip_dst, sizeof(ip_src));
memcpy(&hdr->ip_dst, &ip_src, 4); memcpy(&ip.ip_dst, &ip_src, sizeof(ip_dst));
hdr->ip_sum = inet_checksum(hdr, 20, ~0); ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
/* Fill in ICMP header */ /* Fill in ICMP header */
icmp->icmp_type = ICMP_DEST_UNREACH; icmp.icmp_type = ICMP_DEST_UNREACH;
icmp->icmp_code = code; icmp.icmp_code = code;
icmp->icmp_cksum = 0; icmp.icmp_cksum = 0;
icmp->icmp_cksum = inet_checksum(icmp, 8 + oldlen, ~0); icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
/* Copy structs on stack back to packet */
memcpy(packet->data + ether_size, &ip, ip_size);
memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
packet->len = 14 + 20 + 8 + oldlen; packet->len = ether_size + ip_size + icmp_size + oldlen;
write_packet(packet); write_packet(packet);
} }
@ -261,8 +286,8 @@ static node_t *route_ipv4(vpn_packet_t *packet)
static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
{ {
struct ip6_hdr *hdr; struct ip6_hdr ip6;
struct icmp6_hdr *icmp; struct icmp6_hdr icmp6;
uint16_t checksum; uint16_t checksum;
struct { struct {
@ -272,55 +297,64 @@ static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
uint32_t next; uint32_t next;
} pseudo; } pseudo;
if(ratelimit()) if(ratelimit(3))
return; return;
cp(); cp();
hdr = (struct ip6_hdr *)(packet->data + 14); /* Copy headers from packet to structs on the stack */
icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr));
memcpy(&ip6, packet->data + ether_size, ip6_size);
memcpy(&icmp6, packet->data + ether_size + ip6_size, icmp6_size);
/* Remember original source and destination */ /* Remember original source and destination */
memcpy(&pseudo.ip6_src, &hdr->ip6_dst, 16); memcpy(&pseudo.ip6_src, &ip6.ip6_dst, sizeof(ip6.ip6_src));
memcpy(&pseudo.ip6_dst, &hdr->ip6_src, 16); memcpy(&pseudo.ip6_dst, &ip6.ip6_src, sizeof(ip6.ip6_dst));
pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr);
pseudo.length = ntohs(ip6.ip6_plen) + ip6_size;
if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp)) if(pseudo.length >= IP_MSS - ip6_size - icmp6_size)
pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp); pseudo.length = IP_MSS - ip6_size - icmp6_size;
/* Copy first part of original contents to ICMP message */ /* Copy first part of original contents to ICMP message */
memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length); memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length);
/* Fill in IPv6 header */ /* Fill in IPv6 header */
hdr->ip6_flow = htonl(0x60000000UL); ip6.ip6_flow = htonl(0x60000000UL);
hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length); ip6.ip6_plen = htons(icmp6_size + pseudo.length);
hdr->ip6_nxt = IPPROTO_ICMPV6; ip6.ip6_nxt = IPPROTO_ICMPV6;
hdr->ip6_hlim = 255; ip6.ip6_hlim = 255;
memcpy(&hdr->ip6_dst, &pseudo.ip6_dst, 16); memcpy(&ip6.ip6_src, &pseudo.ip6_src, sizeof(ip6.ip6_src));
memcpy(&hdr->ip6_src, &pseudo.ip6_src, 16); memcpy(&ip6.ip6_dst, &pseudo.ip6_dst, sizeof(ip6.ip6_dst));
/* Fill in ICMP header */ /* Fill in ICMP header */
icmp->icmp6_type = ICMP6_DST_UNREACH; icmp6.icmp6_type = ICMP6_DST_UNREACH;
icmp->icmp6_code = code; icmp6.icmp6_code = code;
icmp->icmp6_cksum = 0; icmp6.icmp6_cksum = 0;
/* Create pseudo header */ /* Create pseudo header */
pseudo.length = htonl(sizeof(*icmp) + pseudo.length); pseudo.length = htonl(icmp6_size + pseudo.length);
pseudo.next = htonl(IPPROTO_ICMPV6); pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */ /* Generate checksum */
checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
checksum = inet_checksum(icmp, ntohl(pseudo.length), checksum); checksum = inet_checksum(&icmp6, icmp6_size, checksum);
checksum = inet_checksum(packet->data + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum);
icmp->icmp6_cksum = checksum; icmp6.icmp6_cksum = checksum;
/* Copy structs on stack back to packet */
memcpy(packet->data + ether_size, &ip6, ip6_size);
memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size);
packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length); packet->len = ether_size + ip6_size + ntohl(pseudo.length);
write_packet(packet); write_packet(packet);
} }
@ -358,9 +392,9 @@ static node_t *route_ipv6(vpn_packet_t *packet)
static void route_neighborsol(vpn_packet_t *packet) static void route_neighborsol(vpn_packet_t *packet)
{ {
struct ip6_hdr *hdr; struct ip6_hdr ip6;
struct nd_neighbor_solicit *ns; struct nd_neighbor_solicit ns;
struct nd_opt_hdr *opt; struct nd_opt_hdr opt;
subnet_t *subnet; subnet_t *subnet;
uint16_t checksum; uint16_t checksum;
@ -373,34 +407,37 @@ static void route_neighborsol(vpn_packet_t *packet)
cp(); cp();
hdr = (struct ip6_hdr *)(packet->data + 14); /* Copy headers from packet to structs on the stack */
ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr));
opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns)); memcpy(&ip6, packet->data + ether_size, ip6_size);
memcpy(&ns, packet->data + ether_size + ip6_size, ns_size);
memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size);
/* First, snatch the source address from the neighbor solicitation packet */ /* First, snatch the source address from the neighbor solicitation packet */
if(overwrite_mac) if(overwrite_mac)
memcpy(mymac.x, packet->data + 6, 6); memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
/* Check if this is a valid neighbor solicitation request */ /* Check if this is a valid neighbor solicitation request */
if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT || if(ns.nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
opt->nd_opt_type != ND_OPT_SOURCE_LINKADDR) { opt.nd_opt_type != ND_OPT_SOURCE_LINKADDR) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request"));
return; return;
} }
/* Create pseudo header */ /* Create pseudo header */
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16); memcpy(&pseudo.ip6_src, &ip6.ip6_src, sizeof(ip6.ip6_src));
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16); memcpy(&pseudo.ip6_dst, &ip6.ip6_dst, sizeof(ip6.ip6_dst));
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6); pseudo.length = htonl(ns_size + opt_size + ETH_ALEN);
pseudo.next = htonl(IPPROTO_ICMPV6); pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */ /* Generate checksum */
checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); checksum = inet_checksum(&ns, ns_size, checksum);
checksum = inet_checksum(&opt, opt_size, checksum);
if(checksum) { if(checksum) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request"));
@ -409,18 +446,18 @@ static void route_neighborsol(vpn_packet_t *packet)
/* Check if the IPv6 address exists on the VPN */ /* Check if the IPv6 address exists on the VPN */
subnet = lookup_subnet_ipv6((ipv6_t *) &ns->nd_ns_target); subnet = lookup_subnet_ipv6((ipv6_t *) &ns.nd_ns_target);
if(!subnet) { if(!subnet) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"), ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
ntohs(((uint16_t *) &ns->nd_ns_target)[0]), ntohs(((uint16_t *) &ns.nd_ns_target)[0]),
ntohs(((uint16_t *) &ns->nd_ns_target)[1]), ntohs(((uint16_t *) &ns.nd_ns_target)[1]),
ntohs(((uint16_t *) &ns->nd_ns_target)[2]), ntohs(((uint16_t *) &ns.nd_ns_target)[2]),
ntohs(((uint16_t *) &ns->nd_ns_target)[3]), ntohs(((uint16_t *) &ns.nd_ns_target)[3]),
ntohs(((uint16_t *) &ns->nd_ns_target)[4]), ntohs(((uint16_t *) &ns.nd_ns_target)[4]),
ntohs(((uint16_t *) &ns->nd_ns_target)[5]), ntohs(((uint16_t *) &ns.nd_ns_target)[5]),
ntohs(((uint16_t *) &ns->nd_ns_target)[6]), ntohs(((uint16_t *) &ns.nd_ns_target)[6]),
ntohs(((uint16_t *) &ns->nd_ns_target)[7])); ntohs(((uint16_t *) &ns.nd_ns_target)[7]));
return; return;
} }
@ -432,35 +469,39 @@ static void route_neighborsol(vpn_packet_t *packet)
/* Create neighbor advertation reply */ /* Create neighbor advertation reply */
memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */ memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
packet->data[ETHER_ADDR_LEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
memcpy(&hdr->ip6_dst, &hdr->ip6_src, 16); /* swap destination and source protocol address */ memcpy(&ip6.ip6_src, &ns.nd_ns_target, sizeof(ip6.ip6_src)); /* swap destination and source protocol address */
memcpy(&hdr->ip6_src, &ns->nd_ns_target, 16); /* ... */ memcpy(&ip6.ip6_dst, &ip6.ip6_src, sizeof(ip6.ip6_dst)); /* ... */
memcpy((char *) opt + sizeof(*opt), packet->data + ETHER_ADDR_LEN, 6); /* add fake source hard addr */ memcpy(&opt + opt_size, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
ns->nd_ns_hdr.icmp6_cksum = 0; ns.nd_ns_cksum = 0;
ns->nd_ns_hdr.icmp6_type = ND_NEIGHBOR_ADVERT; ns.nd_ns_type = ND_NEIGHBOR_ADVERT;
ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[0] = 0x40; /* Set solicited flag */ ns.nd_ns_reserved = htonl(0x40000000UL); /* Set solicited flag */
ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[1] = opt.nd_opt_type = ND_OPT_TARGET_LINKADDR;
ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[2] =
ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[3] = 0;
opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
/* Create pseudo header */ /* Create pseudo header */
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16); memcpy(&pseudo.ip6_src, &ip6.ip6_src, sizeof(ip6.ip6_src));
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16); memcpy(&pseudo.ip6_dst, &ip6.ip6_dst, sizeof(ip6.ip6_dst));
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6); pseudo.length = htonl(ns_size + opt_size + ETH_ALEN);
pseudo.next = htonl(IPPROTO_ICMPV6); pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */ /* Generate checksum */
checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); checksum = inet_checksum(&ns, ns_size, checksum);
checksum = inet_checksum(&opt, opt_size, checksum);
ns->nd_ns_hdr.icmp6_cksum = checksum; ns.nd_ns_hdr.icmp6_cksum = checksum;
/* Copy structs on stack back to packet */
memcpy(packet->data + ether_size, &ip6, ip6_size);
memcpy(packet->data + ether_size + ip6_size, &ns, ns_size);
memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size);
write_packet(packet); write_packet(packet);
} }
@ -469,40 +510,37 @@ static void route_neighborsol(vpn_packet_t *packet)
static void route_arp(vpn_packet_t *packet) static void route_arp(vpn_packet_t *packet)
{ {
struct ether_arp *arp; struct ether_arp arp;
subnet_t *subnet; subnet_t *subnet;
uint8_t ipbuf[4]; struct in_addr addr;
cp(); cp();
/* First, snatch the source address from the ARP packet */ /* First, snatch the source address from the ARP packet */
if(overwrite_mac) if(overwrite_mac)
memcpy(mymac.x, packet->data + 6, 6); memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
/* This routine generates replies to ARP requests. /* Copy headers from packet to structs on the stack */
You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD).
Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
*/
arp = (struct ether_arp *)(packet->data + 14); memcpy(&arp, packet->data + ether_size, arp_size);
/* Check if this is a valid ARP request */ /* Check if this is a valid ARP request */
if(ntohs(arp->arp_hrd) != ARPHRD_ETHER || ntohs(arp->arp_pro) != ETHERTYPE_IP || if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP ||
arp->arp_hln != ETHER_ADDR_LEN || arp->arp_pln != 4 || ntohs(arp->arp_op) != ARPOP_REQUEST) { arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof(addr) || ntohs(arp.arp_op) != ARPOP_REQUEST) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request"));
return; return;
} }
/* Check if the IPv4 address exists on the VPN */ /* Check if the IPv4 address exists on the VPN */
subnet = lookup_subnet_ipv4((ipv4_t *) arp->arp_tpa); subnet = lookup_subnet_ipv4((ipv4_t *) &arp.arp_tpa);
if(!subnet) { if(!subnet) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"), ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"),
arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], arp.arp_tpa[0], arp.arp_tpa[1], arp.arp_tpa[2],
arp->arp_tpa[3]); arp.arp_tpa[3]);
return; return;
} }
@ -511,16 +549,20 @@ static void route_arp(vpn_packet_t *packet)
if(subnet->owner == myself) if(subnet->owner == myself)
return; /* silently ignore */ return; /* silently ignore */
memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */ memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
packet->data[ETHER_ADDR_LEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
memcpy(ipbuf, arp->arp_tpa, 4); /* save protocol addr */ memcpy(&addr, arp.arp_tpa, sizeof(addr)); /* save protocol addr */
memcpy(arp->arp_tpa, arp->arp_spa, 4); /* swap destination and source protocol address */ memcpy(arp.arp_tpa, arp.arp_spa, sizeof(addr)); /* swap destination and source protocol address */
memcpy(arp->arp_spa, ipbuf, 4); /* ... */ memcpy(arp.arp_spa, &addr, sizeof(addr)); /* ... */
memcpy(arp->arp_tha, arp->arp_sha, 10); /* set target hard/proto addr */ memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN); /* set target hard/proto addr */
memcpy(arp->arp_sha, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* add fake source hard addr */ memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
arp->arp_op = htons(ARPOP_REPLY); arp.arp_op = htons(ARPOP_REPLY);
/* Copy structs on stack back to packet */
memcpy(packet->data + ether_size, &arp, arp_size);
write_packet(packet); write_packet(packet);
} }
@ -532,7 +574,7 @@ void route_outgoing(vpn_packet_t *packet)
cp(); cp();
if(packet->len < 14) { if(packet->len < ether_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
return; return;
} }
@ -543,8 +585,8 @@ void route_outgoing(vpn_packet_t *packet)
case RMODE_ROUTER: case RMODE_ROUTER:
type = ntohs(*((uint16_t *)(&packet->data[12]))); type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) { switch (type) {
case 0x0800: case ETH_P_IP:
if(packet->len < 34) { if(packet->len < ether_size + ip_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
return; return;
} }
@ -552,21 +594,21 @@ void route_outgoing(vpn_packet_t *packet)
n = route_ipv4(packet); n = route_ipv4(packet);
break; break;
case 0x86DD: case ETH_P_IPV6:
if(packet->len < 54) { if(packet->len < ether_size + ip6_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
return; return;
} }
if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= 62 && packet->data[54] == ND_NEIGHBOR_SOLICIT) { if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= ether_size + ip6_size + ns_size && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
route_neighborsol(packet); route_neighborsol(packet);
return; return;
} }
n = route_ipv6(packet); n = route_ipv6(packet);
break; break;
case 0x0806: case ETH_P_ARP:
if(packet->len < 42) { if(packet->len < ether_size + arp_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
return; return;
} }
@ -598,9 +640,8 @@ void route_outgoing(vpn_packet_t *packet)
void route_incoming(node_t *source, vpn_packet_t *packet) void route_incoming(node_t *source, vpn_packet_t *packet)
{ {
if(packet->len < 14) { if(packet->len < ether_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"), ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
source->name, source->hostname);
return; return;
} }
@ -612,8 +653,8 @@ void route_incoming(node_t *source, vpn_packet_t *packet)
type = ntohs(*((uint16_t *)(&packet->data[12]))); type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) { switch (type) {
case 0x0800: case ETH_P_IP:
if(packet->len < 34) { if(packet->len < ether_size + ip_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
return; return;
} }
@ -621,8 +662,8 @@ void route_incoming(node_t *source, vpn_packet_t *packet)
n = route_ipv4(packet); n = route_ipv4(packet);
break; break;
case 0x86DD: case ETH_P_IPV6:
if(packet->len < 54) { if(packet->len < ether_size + ip6_size) {
ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
return; return;
} }
@ -638,7 +679,7 @@ void route_incoming(node_t *source, vpn_packet_t *packet)
if(n) { if(n) {
if(n == myself) { if(n == myself) {
if(overwrite_mac) if(overwrite_mac)
memcpy(packet->data, mymac.x, 6); memcpy(packet->data, mymac.x, ETH_ALEN);
write_packet(packet); write_packet(packet);
} else } else
send_packet(n, packet); send_packet(n, packet);