uint32_t get_next_seqnum(struct tcp_buf *tcp_buffer, int seq, struct ofpbuf *packet, bool loss_recovery){
unsigned int size;
uint8_t tcp_flags;
struct tcp_header *tcp;
tcp = ofpbuf_l4(packet);
tcp_flags = TCP_FLAGS(tcp->tcp_ctl);
size = get_tcp_payload_size(packet);
// Sliding the expected seq forward to recover from the probable burst
// of losts packets
if(loss_recovery){
return (seq + (get_tcp_payload_size(packet)*LOSS_RECOVERY_SLIDING)) % 0xFFFFFFFF;
}
else {
if(tcp_flags & TCP_FIN){
VLOG_INFO("Last packet above was FIN");
tcp_buffer->fin_state = true;
return (seq + size + 1) % 0xFFFFFFFF;
}
else{
return (seq + size) % 0xFFFFFFFF;
}
}
}
/* If 'packet' is a TCP packet, returns the TCP flags. Otherwise, returns 0.
*
* 'flow' must be the flow corresponding to 'packet' and 'packet''s header
* pointers must be properly initialized (e.g. with flow_extract()). */
uint8_t
packet_get_tcp_flags(const struct ofpbuf *packet, const struct flow *flow)
{
if ((flow->dl_type == htons(ETH_TYPE_IP) ||
flow->dl_type == htons(ETH_TYPE_IPV6)) &&
flow->nw_proto == IPPROTO_TCP && packet->l7) {
const struct tcp_header *tcp = packet->l4;
return TCP_FLAGS(tcp->tcp_ctl);
} else {
return 0;
}
}
/* Extracts the flow stats for a packet. The 'flow' and 'packet'
* arguments must have been initialized through a call to flow_extract().
*/
void
flow_extract_stats(const flow_t *flow, struct ofpbuf *packet,
struct odp_flow_stats *stats)
{
memset(stats, '\0', sizeof(*stats));
if ((flow->dl_type == htons(ETH_TYPE_IP)) && packet->l4) {
if ((flow->nw_proto == IP_TYPE_TCP) && packet->l7) {
struct tcp_header *tcp = packet->l4;
stats->tcp_flags = TCP_FLAGS(tcp->tcp_ctl);
}
}
stats->n_bytes = packet->size;
stats->n_packets = 1;
}
/* Appends a string representation of 'match' to 's'. If 'priority' is
* different from OFP_DEFAULT_PRIORITY, includes it in 's'. */
void
match_format(const struct match *match, struct ds *s, unsigned int priority)
{
const struct flow_wildcards *wc = &match->wc;
size_t start_len = s->length;
const struct flow *f = &match->flow;
bool skip_type = false;
bool skip_proto = false;
int i;
BUILD_ASSERT_DECL(FLOW_WC_SEQ == 26);
if (priority != OFP_DEFAULT_PRIORITY) {
ds_put_format(s, "priority=%u,", priority);
}
format_uint32_masked(s, "pkt_mark", f->pkt_mark, wc->masks.pkt_mark);
if (wc->masks.recirc_id) {
format_uint32_masked(s, "recirc_id", f->recirc_id,
wc->masks.recirc_id);
}
if (f->dp_hash && wc->masks.dp_hash) {
format_uint32_masked(s, "dp_hash", f->dp_hash,
wc->masks.dp_hash);
}
if (wc->masks.skb_priority) {
ds_put_format(s, "skb_priority=%#"PRIx32",", f->skb_priority);
}
if (wc->masks.dl_type) {
skip_type = true;
if (f->dl_type == htons(ETH_TYPE_IP)) {
if (wc->masks.nw_proto) {
skip_proto = true;
if (f->nw_proto == IPPROTO_ICMP) {
ds_put_cstr(s, "icmp,");
} else if (f->nw_proto == IPPROTO_TCP) {
ds_put_cstr(s, "tcp,");
} else if (f->nw_proto == IPPROTO_UDP) {
ds_put_cstr(s, "udp,");
} else if (f->nw_proto == IPPROTO_SCTP) {
ds_put_cstr(s, "sctp,");
} else {
ds_put_cstr(s, "ip,");
skip_proto = false;
}
} else {
ds_put_cstr(s, "ip,");
}
} else if (f->dl_type == htons(ETH_TYPE_IPV6)) {
if (wc->masks.nw_proto) {
skip_proto = true;
if (f->nw_proto == IPPROTO_ICMPV6) {
ds_put_cstr(s, "icmp6,");
} else if (f->nw_proto == IPPROTO_TCP) {
ds_put_cstr(s, "tcp6,");
} else if (f->nw_proto == IPPROTO_UDP) {
ds_put_cstr(s, "udp6,");
} else if (f->nw_proto == IPPROTO_SCTP) {
ds_put_cstr(s, "sctp6,");
} else {
ds_put_cstr(s, "ipv6,");
skip_proto = false;
}
} else {
ds_put_cstr(s, "ipv6,");
}
} else if (f->dl_type == htons(ETH_TYPE_ARP)) {
ds_put_cstr(s, "arp,");
} else if (f->dl_type == htons(ETH_TYPE_RARP)) {
ds_put_cstr(s, "rarp,");
} else if (f->dl_type == htons(ETH_TYPE_MPLS)) {
ds_put_cstr(s, "mpls,");
} else if (f->dl_type == htons(ETH_TYPE_MPLS_MCAST)) {
ds_put_cstr(s, "mplsm,");
} else {
skip_type = false;
}
}
for (i = 0; i < FLOW_N_REGS; i++) {
#define REGNAME_LEN 20
char regname[REGNAME_LEN];
if (snprintf(regname, REGNAME_LEN, "reg%d", i) >= REGNAME_LEN) {
strcpy(regname, "reg?");
}
format_uint32_masked(s, regname, f->regs[i], wc->masks.regs[i]);
}
format_flow_tunnel(s, match);
format_be64_masked(s, "metadata", f->metadata, wc->masks.metadata);
if (wc->masks.in_port.ofp_port) {
ds_put_cstr(s, "in_port=");
ofputil_format_port(f->in_port.ofp_port, s);
ds_put_char(s, ',');
}
if (wc->masks.vlan_tci) {
ovs_be16 vid_mask = wc->masks.vlan_tci & htons(VLAN_VID_MASK);
ovs_be16 pcp_mask = wc->masks.vlan_tci & htons(VLAN_PCP_MASK);
ovs_be16 cfi = wc->masks.vlan_tci & htons(VLAN_CFI);
if (cfi && f->vlan_tci & htons(VLAN_CFI)
&& (!vid_mask || vid_mask == htons(VLAN_VID_MASK))
&& (!pcp_mask || pcp_mask == htons(VLAN_PCP_MASK))
&& (vid_mask || pcp_mask)) {
if (vid_mask) {
ds_put_format(s, "dl_vlan=%"PRIu16",",
vlan_tci_to_vid(f->vlan_tci));
}
if (pcp_mask) {
ds_put_format(s, "dl_vlan_pcp=%d,",
vlan_tci_to_pcp(f->vlan_tci));
}
} else if (wc->masks.vlan_tci == htons(0xffff)) {
ds_put_format(s, "vlan_tci=0x%04"PRIx16",", ntohs(f->vlan_tci));
} else {
ds_put_format(s, "vlan_tci=0x%04"PRIx16"/0x%04"PRIx16",",
ntohs(f->vlan_tci), ntohs(wc->masks.vlan_tci));
}
}
format_eth_masked(s, "dl_src", f->dl_src, wc->masks.dl_src);
format_eth_masked(s, "dl_dst", f->dl_dst, wc->masks.dl_dst);
if (!skip_type && wc->masks.dl_type) {
ds_put_format(s, "dl_type=0x%04"PRIx16",", ntohs(f->dl_type));
}
if (f->dl_type == htons(ETH_TYPE_IPV6)) {
format_ipv6_netmask(s, "ipv6_src", &f->ipv6_src, &wc->masks.ipv6_src);
format_ipv6_netmask(s, "ipv6_dst", &f->ipv6_dst, &wc->masks.ipv6_dst);
if (wc->masks.ipv6_label) {
if (wc->masks.ipv6_label == OVS_BE32_MAX) {
ds_put_format(s, "ipv6_label=0x%05"PRIx32",",
ntohl(f->ipv6_label));
} else {
ds_put_format(s, "ipv6_label=0x%05"PRIx32"/0x%05"PRIx32",",
ntohl(f->ipv6_label),
ntohl(wc->masks.ipv6_label));
}
}
} else if (f->dl_type == htons(ETH_TYPE_ARP) ||
f->dl_type == htons(ETH_TYPE_RARP)) {
format_ip_netmask(s, "arp_spa", f->nw_src, wc->masks.nw_src);
format_ip_netmask(s, "arp_tpa", f->nw_dst, wc->masks.nw_dst);
} else {
format_ip_netmask(s, "nw_src", f->nw_src, wc->masks.nw_src);
format_ip_netmask(s, "nw_dst", f->nw_dst, wc->masks.nw_dst);
}
if (!skip_proto && wc->masks.nw_proto) {
if (f->dl_type == htons(ETH_TYPE_ARP) ||
f->dl_type == htons(ETH_TYPE_RARP)) {
ds_put_format(s, "arp_op=%"PRIu8",", f->nw_proto);
} else {
ds_put_format(s, "nw_proto=%"PRIu8",", f->nw_proto);
}
}
if (f->dl_type == htons(ETH_TYPE_ARP) ||
f->dl_type == htons(ETH_TYPE_RARP)) {
format_eth_masked(s, "arp_sha", f->arp_sha, wc->masks.arp_sha);
format_eth_masked(s, "arp_tha", f->arp_tha, wc->masks.arp_tha);
}
if (wc->masks.nw_tos & IP_DSCP_MASK) {
ds_put_format(s, "nw_tos=%"PRIu8",", f->nw_tos & IP_DSCP_MASK);
}
if (wc->masks.nw_tos & IP_ECN_MASK) {
ds_put_format(s, "nw_ecn=%"PRIu8",", f->nw_tos & IP_ECN_MASK);
}
if (wc->masks.nw_ttl) {
ds_put_format(s, "nw_ttl=%"PRIu8",", f->nw_ttl);
}
if (wc->masks.mpls_lse[0] & htonl(MPLS_LABEL_MASK)) {
ds_put_format(s, "mpls_label=%"PRIu32",",
mpls_lse_to_label(f->mpls_lse[0]));
}
if (wc->masks.mpls_lse[0] & htonl(MPLS_TC_MASK)) {
ds_put_format(s, "mpls_tc=%"PRIu8",",
mpls_lse_to_tc(f->mpls_lse[0]));
}
if (wc->masks.mpls_lse[0] & htonl(MPLS_TTL_MASK)) {
ds_put_format(s, "mpls_ttl=%"PRIu8",",
mpls_lse_to_ttl(f->mpls_lse[0]));
}
if (wc->masks.mpls_lse[0] & htonl(MPLS_BOS_MASK)) {
ds_put_format(s, "mpls_bos=%"PRIu8",",
mpls_lse_to_bos(f->mpls_lse[0]));
}
format_be32_masked(s, "mpls_lse1", f->mpls_lse[1], wc->masks.mpls_lse[1]);
format_be32_masked(s, "mpls_lse2", f->mpls_lse[2], wc->masks.mpls_lse[2]);
switch (wc->masks.nw_frag) {
case FLOW_NW_FRAG_ANY | FLOW_NW_FRAG_LATER:
ds_put_format(s, "nw_frag=%s,",
f->nw_frag & FLOW_NW_FRAG_ANY
? (f->nw_frag & FLOW_NW_FRAG_LATER ? "later" : "first")
: (f->nw_frag & FLOW_NW_FRAG_LATER ? "<error>" : "no"));
break;
case FLOW_NW_FRAG_ANY:
ds_put_format(s, "nw_frag=%s,",
f->nw_frag & FLOW_NW_FRAG_ANY ? "yes" : "no");
break;
case FLOW_NW_FRAG_LATER:
ds_put_format(s, "nw_frag=%s,",
f->nw_frag & FLOW_NW_FRAG_LATER ? "later" : "not_later");
break;
}
if (f->dl_type == htons(ETH_TYPE_IP) &&
f->nw_proto == IPPROTO_ICMP) {
format_be16_masked(s, "icmp_type", f->tp_src, wc->masks.tp_src);
format_be16_masked(s, "icmp_code", f->tp_dst, wc->masks.tp_dst);
//add by ljx
// format_be16_masked(s, "icmp_identify", *(ovs_be16*)(&f->ipv6_label),
// *(ovs_be16*)&wc->masks.ipv6_label);
format_be16_masked(s, "icmp_identify", f->ipv6_label, wc->masks.ipv6_label);
} else if (f->dl_type == htons(ETH_TYPE_IPV6) &&
f->nw_proto == IPPROTO_ICMPV6) {
format_be16_masked(s, "icmp_type", f->tp_src, wc->masks.tp_src);
format_be16_masked(s, "icmp_code", f->tp_dst, wc->masks.tp_dst);
format_ipv6_netmask(s, "nd_target", &f->nd_target,
&wc->masks.nd_target);
format_eth_masked(s, "nd_sll", f->arp_sha, wc->masks.arp_sha);
format_eth_masked(s, "nd_tll", f->arp_tha, wc->masks.arp_tha);
} else {
format_be16_masked(s, "tp_src", f->tp_src, wc->masks.tp_src);
format_be16_masked(s, "tp_dst", f->tp_dst, wc->masks.tp_dst);
}
if (is_ip_any(f) && f->nw_proto == IPPROTO_TCP && wc->masks.tcp_flags) {
uint16_t mask = TCP_FLAGS(wc->masks.tcp_flags);
if (mask == TCP_FLAGS(OVS_BE16_MAX)) {
ds_put_format(s, "tcp_flags=0x%03"PRIx16",", ntohs(f->tcp_flags));
} else {
format_flags_masked(s, "tcp_flags", packet_tcp_flag_to_string,
ntohs(f->tcp_flags), mask);
}
}
if (s->length > start_len && ds_last(s) == ',') {
s->length--;
}
}
int get_packet_list(struct ofpbuf *out_packets[], struct ofpbuf * packet, uint32_t flow_id, uint32_t in_port){
struct tcp_buf * tcp_buf;
uint8_t tcp_flags;
struct tcp_header *tcp;
uint32_t seq;
int i, out_packets_count;
uint32_t seq_work;
struct ofpbuf * buf_pkt;
int removed_items;
// Getting the buffer for the flow, or creating a new one if
// not existing
tcp_buf = get_tcp_buf(flow_id);
tcp = ofpbuf_l4(packet);
tcp_flags = TCP_FLAGS(tcp->tcp_ctl);
seq = get_tcp_seq(packet);
out_packets_count = 0;
if (tcp_flags & TCP_SYN){
tcp_buf->expected_seqnum = seq+1;
VLOG_INFO("[SYN packet] sequence: %" PRIu32 " expected: %" PRIu32 " in_port: %"PRIu32 " size: %d",
seq, tcp_buf->expected_seqnum, in_port, tcp_buf->inserted_items);
out_packets[out_packets_count] = packet;
out_packets_count++;
}
else if(tcp_buf->fin_state){
delete_tcp_buf(tcp_buf);
out_packets[out_packets_count] = packet;
out_packets_count++;
}
// Retransmission or packets which come without a SYN or after a FIN
// Just send out
else if(tcp_buf->expected_seqnum == -1){
out_packets[out_packets_count] = packet;
out_packets_count++;
}
// Sending out and checking if the the gap in the reordering buffer has been filled
else if(seq <= tcp_buf->expected_seqnum){
VLOG_INFO("[sending in order packet] seq: %"PRIu32 " expected: %" PRIu32 " in_port: %"PRIu32 " size: %d",
seq, tcp_buf->expected_seqnum, in_port, tcp_buf->inserted_items);
out_packets[out_packets_count] = packet;
out_packets_count++;
tcp_buf->consecutive_buffering_events = 0;
// Increasing sequence only if it matches
if(seq == tcp_buf->expected_seqnum){
tcp_buf->expected_seqnum = get_next_seqnum(tcp_buf, tcp_buf->expected_seqnum, packet, false);
}
// Check if there are packets waiting to be sent
removed_items = 0;
for(i=tcp_buf->inserted_items-1;i>= 0;i--){
seq_work = get_tcp_seq(tcp_buf->buffer[i]);
if(seq_work <= tcp_buf->expected_seqnum){
VLOG_INFO("[sending out from buffer] sequence: %" PRIu32 " expected: %" PRIu32 " size: %d",
seq_work, tcp_buf->expected_seqnum, tcp_buf->inserted_items - removed_items);
removed_items++;
out_packets[out_packets_count] = tcp_buf->buffer[i];
out_packets_count++;
if(seq_work == tcp_buf->expected_seqnum){
tcp_buf->expected_seqnum = get_next_seqnum(tcp_buf, tcp_buf->expected_seqnum, tcp_buf->buffer[i], false);
}
}
}
tcp_buf->inserted_items = tcp_buf->inserted_items - removed_items;
}
// Buffer not full yet, buffering the packet
else if(tcp_buf->inserted_items<TCP_BUF_SIZE && tcp_buf->consecutive_buffering_events < CONSECUTIVE_BUFFERING_TREESHOLD){
VLOG_INFO("[buffering] sequence: %"PRIu32 " expected: %" PRIu32 " in_port: %"PRIu32 " size: %d",
seq, tcp_buf->expected_seqnum, in_port, tcp_buf->inserted_items);
buf_pkt = ofpbuf_clone(packet);
insert_descending_order(tcp_buf, buf_pkt);
}
// Buffer full or loss event detecte
else{
VLOG_WARN("!! -- Empty Buffer Event -- !!");
if(tcp_buf->consecutive_buffering_events >= CONSECUTIVE_BUFFERING_TREESHOLD)
syslog(LOG_INFO, "!! -- Because of an apparent loss -- !!");
seq_work = get_tcp_seq(tcp_buf->buffer[tcp_buf->inserted_items-1]);
// If incoming packet has the smallest sequence
if(seq<seq_work){
VLOG_INFO("[resetting buffer] sequence: %" PRIu32, seq);
out_packets[out_packets_count] = packet;
out_packets_count++;
}
// If a packet in the buffer has the smallest sequence
else{
VLOG_INFO("[resetting] sequence: %" PRIu32, get_tcp_seq(tcp_buf->buffer[tcp_buf->inserted_items-1]));
out_packets[out_packets_count] = tcp_buf->buffer[tcp_buf->inserted_items-1];
out_packets_count++;
tcp_buf->inserted_items--;
buf_pkt = ofpbuf_clone(packet);
insert_descending_order(tcp_buf, buf_pkt);
}
// Completely empty the buffer
for(i=tcp_buf->inserted_items-1;i>= 0;i--){
seq_work = get_tcp_seq(tcp_buf->buffer[i]);
VLOG_INFO("resetting %" PRIu32, seq_work);
get_next_seqnum(tcp_buf, seq_work, tcp_buf->buffer[i], false);
out_packets[out_packets_count] = tcp_buf->buffer[i];
out_packets_count++;
// Adjusting seqnum
if(i==0){
tcp_buf->expected_seqnum = get_next_seqnum(tcp_buf, seq_work, tcp_buf->buffer[i], false);
}
}
tcp_buf->inserted_items=0;
if(tcp_buf->consecutive_buffering_events >= CONSECUTIVE_BUFFERING_TREESHOLD){
tcp_buf->expected_seqnum = get_next_seqnum(tcp_buf, tcp_buf->expected_seqnum, packet, true);
}
}
return out_packets_count;
}
/***************************************************************************
*
* Asynchronous receive thread
*
* The transmit and receive threads run independently of each other. There
* is no record what was transmitted. Instead, the transmit thread sets a
* "SYN-cookie" in transmitted packets, which the receive thread will then
* use to match up requests with responses.
***************************************************************************/
static void
receive_thread(void *v)
{
struct ThreadPair *parms = (struct ThreadPair *)v;
const struct Masscan *masscan = parms->masscan;
struct Output *out;
struct DedupTable *dedup;
struct PcapFile *pcapfile = NULL;
struct TCP_ConnectionTable *tcpcon = 0;
LOG(1, "recv: start receive thread #%u\n", parms->nic_index);
/* Lock this thread to a CPU. Transmit threads are on even CPUs,
* receive threads on odd CPUs */
if (pixie_cpu_get_count() > 1) {
unsigned cpu_count = pixie_cpu_get_count();
unsigned cpu = parms->nic_index * 2 + 1;
while (cpu >= cpu_count) {
cpu -= cpu_count;
cpu++;
}
pixie_cpu_set_affinity(cpu);
}
/*
* If configured, open a --pcap file for saving raw packets. This is
* so that we can debug scans, but also so that we can look at the
* strange things people send us. Note that we don't record transmitted
* packets, just the packets we've received.
*/
/*if (masscan->pcap_filename[0])
pcapfile = pcapfile_openwrite(masscan->pcap_filename, 1);*/
/*
* Open output. This is where results are reported when saving
* the --output-format to the --output-filename
*/
out = output_create(masscan);
/*
* Create deduplication table. This is so when somebody sends us
* multiple responses, we only record the first one.
*/
dedup = dedup_create();
/*
* Create a TCP connection table for interacting with live
* connections when doing --banners
*/
if (masscan->is_banners) {
tcpcon = tcpcon_create_table(
(size_t)((masscan->max_rate/5) / masscan->nic_count),
parms->transmit_queue,
parms->packet_buffers,
&parms->tmplset->pkts[Proto_TCP],
output_report_banner,
out,
masscan->tcb.timeout
);
}
if (masscan->is_offline) {
while (!control_c_pressed_again)
pixie_usleep(10000);
parms->done_receiving = 1;
return;
}
/*
* Receive packets. This is where we catch any responses and print
* them to the terminal.
*/
LOG(1, "begin receive thread\n");
while (!control_c_pressed_again) {
int status;
unsigned length;
unsigned secs;
unsigned usecs;
const unsigned char *px;
int err;
unsigned x;
struct PreprocessedInfo parsed;
unsigned ip_me;
unsigned ip_them;
unsigned seqno_them;
unsigned seqno_me;
/*
* RECIEVE
*
* This is the boring part of actually receiving a packet
*/
err = rawsock_recv_packet(
parms->adapter,
&length,
&secs,
&usecs,
&px);
if (err != 0)
continue;
/*
* Do any TCP event timeouts based on the current timestamp from
* the packet. For example, if the connection has been open for
* around 10 seconds, we'll close the connection. (--banners)
*/
if (tcpcon) {
tcpcon_timeouts(tcpcon, secs, usecs);
}
if (length > 1514)
continue;
/*
* "Preprocess" the response packet. This means to go through and
* figure out where the TCP/IP headers are and the locations of
* some fields, like IP address and port numbers.
*/
x = preprocess_frame(px, length, 1, &parsed);
if (!x)
continue; /* corrupt packet */
ip_me = parsed.ip_dst[0]<<24 | parsed.ip_dst[1]<<16
| parsed.ip_dst[2]<< 8 | parsed.ip_dst[3]<<0;
ip_them = parsed.ip_src[0]<<24 | parsed.ip_src[1]<<16
| parsed.ip_src[2]<< 8 | parsed.ip_src[3]<<0;
seqno_them = TCP_SEQNO(px, parsed.transport_offset);
seqno_me = TCP_ACKNO(px, parsed.transport_offset);
/* verify: my IP address */
if (parms->adapter_ip != ip_me)
continue;
/*
* Handle non-TCP protocols
*/
switch (parsed.found) {
case FOUND_ARP:
/* OOPS: handle arp instead. Since we may completely bypass the TCP/IP
* stack, we may have to handle ARPs ourself, or the router will
* lose track of us. */
LOGip(2, ip_them, 0, "-> ARP [%u] \n", px[parsed.found_offset]);
arp_response( parms->adapter_ip,
parms->adapter_mac,
px, length,
parms->packet_buffers,
parms->transmit_queue);
continue;
case FOUND_UDP:
case FOUND_DNS:
if (!is_my_port(masscan, parsed.port_dst))
continue;
handle_udp(out, px, length, &parsed);
continue;
case FOUND_ICMP:
handle_icmp(out, px, length, &parsed);
continue;
case FOUND_TCP:
/* fall down to below */
break;
default:
continue;
}
/* verify: my port number */
if (parms->adapter_port != parsed.port_dst)
continue;
/* Save raw packet in --pcap file */
if (pcapfile) {
pcapfile_writeframe(
pcapfile,
px,
length,
length,
secs,
usecs);
}
{
char buf[64];
LOGip(5, ip_them, parsed.port_src, "-> TCP ackno=0x%08x flags=0x%02x(%s)\n",
seqno_me,
TCP_FLAGS(px, parsed.transport_offset),
reason_string(TCP_FLAGS(px, parsed.transport_offset), buf, sizeof(buf)));
}
/* If recording --banners, create a new "TCP Control Block (TCB)" */
if (tcpcon) {
struct TCP_Control_Block *tcb;
/* does a TCB already exist for this connection? */
tcb = tcpcon_lookup_tcb(tcpcon,
ip_me, ip_them,
parsed.port_dst, parsed.port_src);
if (TCP_IS_SYNACK(px, parsed.transport_offset)) {
if (syn_hash(ip_them, parsed.port_src) != seqno_me - 1) {
LOG(2, "%u.%u.%u.%u - bad cookie: ackno=0x%08x expected=0x%08x\n",
(ip_them>>24)&0xff, (ip_them>>16)&0xff, (ip_them>>8)&0xff, (ip_them>>0)&0xff,
seqno_me-1, syn_hash(ip_them, parsed.port_src));
continue;
}
if (tcb == NULL) {
tcb = tcpcon_create_tcb(tcpcon,
ip_me, ip_them,
parsed.port_dst,
parsed.port_src,
seqno_me, seqno_them+1);
}
tcpcon_handle(tcpcon, tcb, TCP_WHAT_SYNACK,
0, 0, secs, usecs, seqno_them+1);
} else if (tcb) {
/* If this is an ACK, then handle that first */
if (TCP_IS_ACK(px, parsed.transport_offset)) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_ACK,
0, seqno_me, secs, usecs, seqno_them);
}
/* If this contains payload, handle that */
if (parsed.app_length) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_DATA,
px + parsed.app_offset, parsed.app_length,
secs, usecs, seqno_them);
}
/* If this is a FIN, handle that. Note that ACK +
* payload + FIN can come together */
if (TCP_IS_FIN(px, parsed.transport_offset)
&& !TCP_IS_RST(px, parsed.transport_offset)) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_FIN,
0, 0, secs, usecs, seqno_them);
}
/* If this is a RST, then we'll be closing the connection */
if (TCP_IS_RST(px, parsed.transport_offset)) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_RST,
0, 0, secs, usecs, seqno_them);
}
} else if (TCP_IS_FIN(px, parsed.transport_offset)) {
/*
* NO TCB!
* This happens when we've sent a FIN, deleted our connection,
* but the other side didn't get the packet.
*/
if (!TCP_IS_RST(px, parsed.transport_offset))
tcpcon_send_FIN(
tcpcon,
ip_me, ip_them,
parsed.port_dst, parsed.port_src,
seqno_them, seqno_me);
}
}