DeforaNetworks/fwknop
DeforaNetworks/fwknop
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Rework the network listening routine some more

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This commit is contained in:
Pierre Pronchery 2018-06-15 17:36:20 -04:00
parent ce9b5fb364
commit 3dc61166a4
1 changed files with 65 additions and 19 deletions
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84
server/process_packet.c
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@ -46,12 +46,16 @@ process_packet_ethernet(fko_srv_options_t * opts, const unsigned char * packet,
unsigned short pkt_len, int caplen, int offset);
static void
process_packet_ipv4(fko_srv_options_t * opts, const unsigned char * packet,
int offset, unsigned char * fr_end);
int offset, unsigned char const * fr_end);
static void
process_packet_ipv6(fko_srv_options_t * opts, const unsigned char * packet,
int offset, unsigned char * fr_end);
int offset, unsigned char const * fr_end);
static void
process_packet_raw(fko_srv_options_t * opts, const unsigned char * packet);
process_packet_loop(fko_srv_options_t * opts, const unsigned char * packet,
unsigned short pkt_len, int caplen);
static void
process_packet_raw(fko_srv_options_t * opts, const unsigned char * packet,
unsigned short pkt_len, int caplen);
void
@ -62,15 +66,19 @@ process_packet(PROCESS_PKT_ARGS_TYPE *args, PACKET_HEADER_META,
int offset = opts->data_link_offset;
if (offset != 0)
#if USE_LIBPCAP
if (offset == sizeof(struct ether_header))
process_packet_ethernet(opts, packet, packet_header->len,
packet_header->caplen, offset);
else if (offset == 4)
process_packet_loop(opts, packet, packet_header->len,
packet_header->caplen);
else if (offset == 0)
process_packet_raw(opts, packet, packet_header->len,
packet_header->caplen);
#else
process_packet_ethernet(opts, packet, pkt_len, pkt_len, offset);
process_packet_raw(opts, packet, pkt_len, pkt_len);
#endif
else
process_packet_raw(opts, packet);
}
@ -84,7 +92,6 @@ process_packet_ethernet(fko_srv_options_t * opts, const unsigned char * packet,
unsigned short eth_type;
#if USE_LIBPCAP
/* Gotta have a complete ethernet header.
*/
if (caplen < ETHER_HDR_LEN)
@ -93,13 +100,6 @@ process_packet_ethernet(fko_srv_options_t * opts, const unsigned char * packet,
/* Determine packet end.
*/
fr_end = (unsigned char *) packet + caplen;
#else
/* This is coming from NFQ and we get the packet length as an arg.
*/
if (pkt_len < ETHER_HDR_LEN)
return;
fr_end = (unsigned char *) packet + pkt_len;
#endif
/* This is a hack to determine if we are using the linux cooked
* interface. We base it on the offset being 16 which is the
@ -147,7 +147,7 @@ process_packet_ethernet(fko_srv_options_t * opts, const unsigned char * packet,
static void
process_packet_ipv4(fko_srv_options_t * opts, const unsigned char * packet,
int offset, unsigned char * fr_end)
int offset, unsigned char const * fr_end)
{
struct iphdr *iph_p;
struct tcphdr *tcph_p;
@ -278,16 +278,62 @@ process_packet_ipv4(fko_srv_options_t * opts, const unsigned char * packet,
static void
process_packet_ipv6(fko_srv_options_t * opts, const unsigned char * packet,
int offset, unsigned char * fr_end)
int offset, unsigned char const * fr_end)
{
/* FIXME implement */
}
static void
process_packet_raw(fko_srv_options_t * opts, const unsigned char * packet)
process_packet_loop(fko_srv_options_t * opts, const unsigned char * packet,
unsigned short pkt_len, int caplen)
{
/* FIXME implement */
uint32_t family;
if (caplen < sizeof(family))
return;
memcpy(&family, packet, sizeof(family));
if (family == AF_INET)
process_packet_ipv4(opts, packet, 4, packet + caplen);
else if (family == AF_INET6)
process_packet_ipv6(opts, packet, 4, packet + caplen);
}
static void
process_packet_raw(fko_srv_options_t * opts, const unsigned char * packet,
unsigned short pkt_len, int caplen)
{
struct iphdr *iph_p;
unsigned char const *fr_end;
/* Gotta have a complete ethernet header.
*/
if (caplen < ETHER_HDR_LEN)
return;
/* Determine packet end.
*/
fr_end = (unsigned char *) packet + caplen;
/* Tentatively pull an IP header.
*/
iph_p = (struct iphdr*)packet;
/* If IP header is past calculated packet end, bail.
*/
if ((unsigned char*)(iph_p + 1) > fr_end)
return;
/* Obtain the IP version.
*/
if (iph_p->version == 6)
process_packet_ipv6(opts, packet, 0, fr_end);
else
process_packet_ipv4(opts, packet, 0, fr_end);
}