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BUG20779: cope with SYN packets received during established states,

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and retransmission of initial SYN.
This commit is contained in:
kieranm 2009-03-31 10:55:31 +00:00
parent e7a2ab5de9
commit baf30f5eae
2 changed files with 13 additions and 2 deletions
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3
CHANGELOG
View File

@ -76,6 +76,9 @@ HISTORY
++ Bugfixes: ++ Bugfixes:
2009-03-31 Kieran Mansley 2009-03-31 Kieran Mansley
* tcp_in.c: cope with SYN packets received during established states,
and retransmission of initial SYN.
* tcp_out.c: set push bit correctly when tcp segments are merged * tcp_out.c: set push bit correctly when tcp segments are merged
2009-03-27 Kieran Mansley 2009-03-27 Kieran Mansley

12
src/core/tcp_in.c
View File

@ -536,6 +536,12 @@ tcp_process(struct tcp_pcb *pcb)
} }
} }
if ((flags & TCP_SYN) && (pcb->state != SYN_SENT && pcb->state != SYN_RCVD)) {
/* Cope with new connection attempt after remote end crashed */
tcp_ack_now(pcb);
return ERR_OK;
}
/* Update the PCB (in)activity timer. */ /* Update the PCB (in)activity timer. */
pcb->tmr = tcp_ticks; pcb->tmr = tcp_ticks;
pcb->keep_cnt_sent = 0; pcb->keep_cnt_sent = 0;
@ -597,8 +603,7 @@ tcp_process(struct tcp_pcb *pcb)
} }
break; break;
case SYN_RCVD: case SYN_RCVD:
if (flags & TCP_ACK && if (flags & TCP_ACK) {
!(flags & TCP_RST)) {
/* expected ACK number? */ /* expected ACK number? */
if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) { if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) {
u16_t old_cwnd; u16_t old_cwnd;
@ -633,6 +638,9 @@ tcp_process(struct tcp_pcb *pcb)
tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src), tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src),
tcphdr->dest, tcphdr->src); tcphdr->dest, tcphdr->src);
} }
} else if ((flags & TCP_SYN) && (seqno == pcb->rcv_nxt - 1)) {
/* Looks like another copy of the SYN - retransmit our SYN-ACK */
tcp_rexmit(pcb);
} }
break; break;
case CLOSE_WAIT: case CLOSE_WAIT: