/* One level of recursion won't kill us */
static void dump_ipv4_packet(struct sbuff *m,
const struct nf_loginfo *info,
const struct sk_buff *skb,
unsigned int iphoff)
{
struct iphdr _iph;
const struct iphdr *ih;
unsigned int logflags;
if (info->type == NF_LOG_TYPE_LOG)
logflags = info->u.log.logflags;
else
logflags = NF_LOG_MASK;
ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
if (ih == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Important fields:
* TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
sb_add(m, "SRC=%pI4 DST=%pI4 ",
&ih->saddr, &ih->daddr);
/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
sb_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
/* Max length: 6 "CE DF MF " */
if (ntohs(ih->frag_off) & IP_CE)
sb_add(m, "CE ");
if (ntohs(ih->frag_off) & IP_DF)
sb_add(m, "DF ");
if (ntohs(ih->frag_off) & IP_MF)
sb_add(m, "MF ");
/* Max length: 11 "FRAG:65535 " */
if (ntohs(ih->frag_off) & IP_OFFSET)
sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
if ((logflags & XT_LOG_IPOPT) &&
ih->ihl * 4 > sizeof(struct iphdr)) {
const unsigned char *op;
unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
unsigned int i, optsize;
optsize = ih->ihl * 4 - sizeof(struct iphdr);
op = skb_header_pointer(skb, iphoff+sizeof(_iph),
optsize, _opt);
if (op == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 127 "OPT (" 15*4*2chars ") " */
sb_add(m, "OPT (");
for (i = 0; i < optsize; i++)
sb_add(m, "%02X", op[i]);
sb_add(m, ") ");
}
switch (ih->protocol) {
case IPPROTO_TCP:
if (dump_tcp_header(m, skb, ih->protocol,
ntohs(ih->frag_off) & IP_OFFSET,
iphoff+ih->ihl*4, logflags))
return;
break;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
if (dump_udp_header(m, skb, ih->protocol,
ntohs(ih->frag_off) & IP_OFFSET,
iphoff+ih->ihl*4))
return;
break;
case IPPROTO_ICMP: {
struct icmphdr _icmph;
const struct icmphdr *ich;
static const size_t required_len[NR_ICMP_TYPES+1]
= { [ICMP_ECHOREPLY] = 4,
[ICMP_DEST_UNREACH]
= 8 + sizeof(struct iphdr),
[ICMP_SOURCE_QUENCH]
= 8 + sizeof(struct iphdr),
[ICMP_REDIRECT]
= 8 + sizeof(struct iphdr),
[ICMP_ECHO] = 4,
[ICMP_TIME_EXCEEDED]
= 8 + sizeof(struct iphdr),
[ICMP_PARAMETERPROB]
= 8 + sizeof(struct iphdr),
[ICMP_TIMESTAMP] = 20,
[ICMP_TIMESTAMPREPLY] = 20,
[ICMP_ADDRESS] = 12,
[ICMP_ADDRESSREPLY] = 12 };
/* Max length: 11 "PROTO=ICMP " */
sb_add(m, "PROTO=ICMP ");
if (ntohs(ih->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
sizeof(_icmph), &_icmph);
if (ich == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
sb_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code);
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (ich->type <= NR_ICMP_TYPES &&
required_len[ich->type] &&
skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
switch (ich->type) {
case ICMP_ECHOREPLY:
case ICMP_ECHO:
/* Max length: 19 "ID=65535 SEQ=65535 " */
sb_add(m, "ID=%u SEQ=%u ",
ntohs(ich->un.echo.id),
ntohs(ich->un.echo.sequence));
break;
case ICMP_PARAMETERPROB:
/* Max length: 14 "PARAMETER=255 " */
sb_add(m, "PARAMETER=%u ",
ntohl(ich->un.gateway) >> 24);
break;
case ICMP_REDIRECT:
/* Max length: 24 "GATEWAY=255.255.255.255 " */
sb_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);
/* Fall through */
case ICMP_DEST_UNREACH:
case ICMP_SOURCE_QUENCH:
case ICMP_TIME_EXCEEDED:
/* Max length: 3+maxlen */
if (!iphoff) { /* Only recurse once. */
sb_add(m, "[");
dump_ipv4_packet(m, info, skb,
iphoff + ih->ihl*4+sizeof(_icmph));
sb_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ich->type == ICMP_DEST_UNREACH &&
ich->code == ICMP_FRAG_NEEDED)
sb_add(m, "MTU=%u ", ntohs(ich->un.frag.mtu));
}
break;
}
/* Max Length */
case IPPROTO_AH: {
struct ip_auth_hdr _ahdr;
const struct ip_auth_hdr *ah;
if (ntohs(ih->frag_off) & IP_OFFSET)
break;
/* Max length: 9 "PROTO=AH " */
sb_add(m, "PROTO=AH ");
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
sizeof(_ahdr), &_ahdr);
if (ah == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
sb_add(m, "SPI=0x%x ", ntohl(ah->spi));
break;
}
case IPPROTO_ESP: {
struct ip_esp_hdr _esph;
const struct ip_esp_hdr *eh;
/* Max length: 10 "PROTO=ESP " */
sb_add(m, "PROTO=ESP ");
if (ntohs(ih->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
sizeof(_esph), &_esph);
if (eh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
sb_add(m, "SPI=0x%x ", ntohl(eh->spi));
break;
}
/* Max length: 10 "PROTO 255 " */
default:
sb_add(m, "PROTO=%u ", ih->protocol);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & XT_LOG_UID) && !iphoff)
dump_sk_uid_gid(m, skb->sk);
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (!iphoff && skb->mark)
sb_add(m, "MARK=0x%x ", skb->mark);
/* Proto Max log string length */
/* IP: 40+46+6+11+127 = 230 */
/* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */
/* UDP: 10+max(25,20) = 35 */
/* UDPLITE: 14+max(25,20) = 39 */
/* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
/* ESP: 10+max(25)+15 = 50 */
/* AH: 9+max(25)+15 = 49 */
/* unknown: 10 */
/* (ICMP allows recursion one level deep) */
/* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */
/* maxlen = 230+ 91 + 230 + 252 = 803 */
}
/* One level of recursion won't kill us */
static void dump_ipv6_packet(struct sbuff *m,
const struct nf_loginfo *info,
const struct sk_buff *skb, unsigned int ip6hoff,
int recurse)
{
u_int8_t currenthdr;
int fragment;
struct ipv6hdr _ip6h;
const struct ipv6hdr *ih;
unsigned int ptr;
unsigned int hdrlen = 0;
unsigned int logflags;
if (info->type == NF_LOG_TYPE_LOG)
logflags = info->u.log.logflags;
else
logflags = NF_LOG_MASK;
ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
if (ih == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
sb_add(m, "LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
(ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
ih->hop_limit,
(ntohl(*(__be32 *)ih) & 0x000fffff));
fragment = 0;
ptr = ip6hoff + sizeof(struct ipv6hdr);
currenthdr = ih->nexthdr;
while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
struct ipv6_opt_hdr _hdr;
const struct ipv6_opt_hdr *hp;
hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
if (hp == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 48 "OPT (...) " */
if (logflags & XT_LOG_IPOPT)
sb_add(m, "OPT ( ");
switch (currenthdr) {
case IPPROTO_FRAGMENT: {
struct frag_hdr _fhdr;
const struct frag_hdr *fh;
sb_add(m, "FRAG:");
fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
&_fhdr);
if (fh == NULL) {
sb_add(m, "TRUNCATED ");
return;
}
/* Max length: 6 "65535 " */
sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8);
/* Max length: 11 "INCOMPLETE " */
if (fh->frag_off & htons(0x0001))
sb_add(m, "INCOMPLETE ");
sb_add(m, "ID:%08x ", ntohl(fh->identification));
if (ntohs(fh->frag_off) & 0xFFF8)
fragment = 1;
hdrlen = 8;
break;
}
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
if (fragment) {
if (logflags & XT_LOG_IPOPT)
sb_add(m, ")");
return;
}
hdrlen = ipv6_optlen(hp);
break;
/* Max Length */
case IPPROTO_AH:
if (logflags & XT_LOG_IPOPT) {
struct ip_auth_hdr _ahdr;
const struct ip_auth_hdr *ah;
/* Max length: 3 "AH " */
sb_add(m, "AH ");
if (fragment) {
sb_add(m, ")");
return;
}
ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
&_ahdr);
if (ah == NULL) {
/*
* Max length: 26 "INCOMPLETE [65535
* bytes] )"
*/
sb_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 15 "SPI=0xF1234567 */
sb_add(m, "SPI=0x%x ", ntohl(ah->spi));
}
hdrlen = (hp->hdrlen+2)<<2;
break;
case IPPROTO_ESP:
if (logflags & XT_LOG_IPOPT) {
struct ip_esp_hdr _esph;
const struct ip_esp_hdr *eh;
/* Max length: 4 "ESP " */
sb_add(m, "ESP ");
if (fragment) {
sb_add(m, ")");
return;
}
/*
* Max length: 26 "INCOMPLETE [65535 bytes] )"
*/
eh = skb_header_pointer(skb, ptr, sizeof(_esph),
&_esph);
if (eh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 16 "SPI=0xF1234567 )" */
sb_add(m, "SPI=0x%x )", ntohl(eh->spi));
}
return;
default:
/* Max length: 20 "Unknown Ext Hdr 255" */
sb_add(m, "Unknown Ext Hdr %u", currenthdr);
return;
}
if (logflags & XT_LOG_IPOPT)
sb_add(m, ") ");
currenthdr = hp->nexthdr;
ptr += hdrlen;
}
switch (currenthdr) {
case IPPROTO_TCP:
if (dump_tcp_header(m, skb, currenthdr, fragment, ptr,
logflags))
return;
break;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
if (dump_udp_header(m, skb, currenthdr, fragment, ptr))
return;
break;
case IPPROTO_ICMPV6: {
struct icmp6hdr _icmp6h;
const struct icmp6hdr *ic;
/* Max length: 13 "PROTO=ICMPv6 " */
sb_add(m, "PROTO=ICMPv6 ");
if (fragment)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
if (ic == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr);
return;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
sb_add(m, "TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
switch (ic->icmp6_type) {
case ICMPV6_ECHO_REQUEST:
case ICMPV6_ECHO_REPLY:
/* Max length: 19 "ID=65535 SEQ=65535 " */
sb_add(m, "ID=%u SEQ=%u ",
ntohs(ic->icmp6_identifier),
ntohs(ic->icmp6_sequence));
break;
case ICMPV6_MGM_QUERY:
case ICMPV6_MGM_REPORT:
case ICMPV6_MGM_REDUCTION:
break;
case ICMPV6_PARAMPROB:
/* Max length: 17 "POINTER=ffffffff " */
sb_add(m, "POINTER=%08x ", ntohl(ic->icmp6_pointer));
/* Fall through */
case ICMPV6_DEST_UNREACH:
case ICMPV6_PKT_TOOBIG:
case ICMPV6_TIME_EXCEED:
/* Max length: 3+maxlen */
if (recurse) {
sb_add(m, "[");
dump_ipv6_packet(m, info, skb,
ptr + sizeof(_icmp6h), 0);
sb_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu));
}
break;
}
/* Max length: 10 "PROTO=255 " */
default:
sb_add(m, "PROTO=%u ", currenthdr);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & XT_LOG_UID) && recurse)
dump_sk_uid_gid(m, skb->sk);
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (!recurse && skb->mark)
sb_add(m, "MARK=0x%x ", skb->mark);
}
int Handle_Packet (char *buffer, int bytes_recieved)
{
IP_Header *ip;
int from_mask[4], to_mask[4];
unsigned int body_offset, body_size;
#ifdef DEBUG
#ifdef UNIX
addr.s_addr = IP_FROM(buffer);
fprintf (stdout, "\n%s", inet_ntoa(addr));
if (test_address (from_mask, flags.from_ip_mask) == 0)
{ fprintf (stdout, " (Src OK)"); }
else
{ fprintf (stdout, " (Src WRONG)"); }
addr.s_addr = IP_TO(buffer);
fprintf (stdout, "\n%s", inet_ntoa(addr));
if (test_address (to_mask, flags.to_ip_mask) == 0)
{ fprintf (stdout, " (Dest OK)"); }
else
{ fprintf (stdout, " (Dest WRONG)"); }
fprintf (stdout, "\nProtocol: %d", PROTOCOL(buffer));
#endif
#endif
/********************************************************/
/* Dumping ethernet headers ? */
/********************************************************/
if (flags.eth_hd == YES)
{ dump_eth_header(ETH_HEADER(buffer), flags.desc); }
if (ETH_FORMAT(buffer) != ETHERNET_II) { return HANDLER_OK; }
/********************************************************/
/* Dump *IP* stuff *ONLY* */
/********************************************************/
if (ETH_TYPE(buffer) == IP_ETH)
{
/********************************************************/
/* Set IP masks */
/********************************************************/
get_addr (IP_FROM(buffer), from_mask);
get_addr (IP_TO(buffer), to_mask);
/*******************************************************/
/* Checking IP address with mask */
/* Checking port numbers */
/* Checking protocol */
/* ... */
/*******************************************************/
if
(
(test_address (from_mask, flags.from_ip_mask) == 0)
&&
(test_address (to_mask, flags.to_ip_mask) == 0)
&& (
(flags.from_port_num == ALL_PORT)
||
(get_src_port_number(buffer) == flags.from_port_num)
)
&& (
(flags.to_port_num == ALL_PORT)
||
(get_dst_port_number(buffer) == flags.to_port_num)
)
&& (
(
(PROTOCOL(buffer) == UDP_PACKET)
&&
(flags.proto_udp == YES)
)
||
(
(PROTOCOL(buffer) == TCP_PACKET)
&&
(flags.proto_tcp == YES)
)
||
(
(PROTOCOL(buffer) == IGMP_PACKET)
&&
(flags.proto_igmp == YES)
)
) /* end test on protocol */
) /* end if condition statement */
{
/******************************************************************/
/* Sanity check */
/******************************************************************/
ip = IP_HEADER(buffer);
if (
((ntohs(ip->ip_total_length)+ETH_HD_LEN) > bytes_recieved)
&&
(flags.verbose == YES)
)
{
fprintf (stdout, "\nWARNING: received %d bytes", bytes_recieved);
fprintf (stdout, "\n total packet size ");
fprintf (stdout, "%d bytes", ntohs(ip->ip_total_length)+ETH_HD_LEN);
fprintf (stdout, "\n\nThis may be a network error ... skipping");
fprintf (stdout, " the packet.\n");
fflush (stdout);
return HANDLER_OK;
}
/******************************************************************/
/* Dump the IP header if requested */
/******************************************************************/
if (flags.ip_hd == YES) { dump_ip_header(ip, flags.desc); }
/******************************************************************/
/* Dump the following headers if requested: */
/* - UDP */
/* - TCP */
/* */
/* In the case of UDP, it may be a RIP message. */
/******************************************************************/
if (PROTOCOL(buffer) == UDP_PACKET)
{
if (flags.udp_hd == YES)
{ dump_udp_header(UDP_HEADER(buffer), flags.desc); }
switch (UDP_SRC_PORT(buffer))
{
case SER_RIP:
if (RIP_VERSION(buffer) == 1)
{ dump_rip1_header (buffer, flags.desc); }
else
{ fprintf (stdout, "\nRIP version 2 !"); };
break;
default:;
}
}
if ((PROTOCOL(buffer) == TCP_PACKET) && (flags.tcp_hd == YES))
{ dump_tcp_header(TCP_HEADER(buffer), flags.desc); }
/********************************************************************/
/* Dump the packet bopy for the following protocols if requested: */
/* - TCP */
/* - UDP */
/* - IGMP */
/* */
/* Note that for IGMP the IGMP header is not separated from the bo- */
/* -dy. */
/********************************************************************/
if (flags.body_level != BD_NONE)
{
/* Get offset and size of the body */
body_info (buffer, &body_offset, &body_size);
switch (flags.body_level)
{
case BD_HEXA : dump_hexa (buffer+body_offset, body_size);
break;
case BD_ASCII : dump_ascii (buffer+body_offset, body_size);
break;
case BD_MIX : dump (buffer+body_offset, body_size); break;
default : {
if (flags.verbose == YES)
{ fprintf (stderr, "\nUnknown dump_body option\n"); }
else
{ fprintf (stderr, "\nInternal error\n"); }
return HANDLER_ERR;
}
} /* end switch (dump_body) */
} /* end if for UDP/TCP/dump_body */
}
return HANDLER_OK;
} /* end if for *IP* stuff *ONLY* */
/*****************************************************/
/* So it is not an IP stuff */
/*****************************************************/
/******************************************************/
/* May be it is ARP ? */
/******************************************************/
if ((ETH_TYPE(buffer) == ARP_ETH) && (flags.proto_arp == YES))
{
dump_ARP_header (ARP_HEADER(buffer), flags.desc);
}
return HANDLER_OK;
}
