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https://github.com/lwip-tcpip/lwip.git
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2005-06-08 Leon Woestenberg <leon.woestenberg@gmx.net>
* tcp_in.c: Send reset on unexpected ACK in two cases. Fix submitted by olaf.peters@technolution.
This commit is contained in:
parent
f9355136d8
commit
baf377679a
@ -509,7 +509,7 @@ tcp_process(struct tcp_pcb *pcb)
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/*if (TCP_SEQ_GEQ(seqno, pcb->rcv_nxt) &&
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TCP_SEQ_LEQ(seqno, pcb->rcv_nxt + pcb->rcv_wnd)) {
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*/
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if(TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, pcb->rcv_nxt+pcb->rcv_wnd)){
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if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, pcb->rcv_nxt+pcb->rcv_wnd)) {
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acceptable = 1;
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}
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}
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@ -538,9 +538,10 @@ tcp_process(struct tcp_pcb *pcb)
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case SYN_SENT:
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LWIP_DEBUGF(TCP_INPUT_DEBUG, ("SYN-SENT: ackno %lu pcb->snd_nxt %lu unacked %lu\n", ackno,
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pcb->snd_nxt, ntohl(pcb->unacked->tcphdr->seqno)));
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/* received SYN ACK with expected sequence number? */
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if ((flags & TCP_ACK) && (flags & TCP_SYN)
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&& ackno == ntohl(pcb->unacked->tcphdr->seqno) + 1) {
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pcb->snd_buf ++;
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pcb->snd_buf++;
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pcb->rcv_nxt = seqno + 1;
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pcb->lastack = ackno;
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pcb->snd_wnd = tcphdr->wnd;
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@ -561,13 +562,18 @@ tcp_process(struct tcp_pcb *pcb)
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TCP_EVENT_CONNECTED(pcb, ERR_OK, err);
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tcp_ack(pcb);
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}
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/* received ACK? possibly a half-open connection */
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else if (flags & TCP_ACK) {
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/* send a RST to bring the other side in a non-synchronized state. */
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tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src),
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tcphdr->dest, tcphdr->src);
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}
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break;
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case SYN_RCVD:
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if (flags & TCP_ACK &&
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!(flags & TCP_RST)) {
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/*if (TCP_SEQ_LT(pcb->lastack, ackno) &&
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TCP_SEQ_LEQ(ackno, pcb->snd_nxt)) { */
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if(TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)){
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/* expected ACK number? */
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if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) {
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pcb->state = ESTABLISHED;
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LWIP_DEBUGF(TCP_DEBUG, ("TCP connection established %u -> %u.\n", inseg.tcphdr->src, inseg.tcphdr->dest));
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#if LWIP_CALLBACK_API
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@ -586,6 +592,12 @@ tcp_process(struct tcp_pcb *pcb)
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tcp_receive(pcb);
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pcb->cwnd = pcb->mss;
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}
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/* incorrect ACK number */
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else {
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/* send RST */
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tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src),
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tcphdr->dest, tcphdr->src);
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}
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}
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break;
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case CLOSE_WAIT:
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@ -602,15 +614,15 @@ tcp_process(struct tcp_pcb *pcb)
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if (flags & TCP_FIN) {
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if (flags & TCP_ACK && ackno == pcb->snd_nxt) {
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LWIP_DEBUGF(TCP_DEBUG,
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("TCP connection closed %d -> %d.\n", inseg.tcphdr->src, inseg.tcphdr->dest));
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tcp_ack_now(pcb);
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tcp_pcb_purge(pcb);
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TCP_RMV(&tcp_active_pcbs, pcb);
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pcb->state = TIME_WAIT;
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TCP_REG(&tcp_tw_pcbs, pcb);
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("TCP connection closed %d -> %d.\n", inseg.tcphdr->src, inseg.tcphdr->dest));
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tcp_ack_now(pcb);
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tcp_pcb_purge(pcb);
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TCP_RMV(&tcp_active_pcbs, pcb);
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pcb->state = TIME_WAIT;
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TCP_REG(&tcp_tw_pcbs, pcb);
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} else {
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tcp_ack_now(pcb);
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pcb->state = CLOSING;
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tcp_ack_now(pcb);
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pcb->state = CLOSING;
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}
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} else if (flags & TCP_ACK && ackno == pcb->snd_nxt) {
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pcb->state = FIN_WAIT_2;
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@ -649,7 +661,6 @@ tcp_process(struct tcp_pcb *pcb)
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default:
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break;
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}
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return ERR_OK;
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}
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