tcp_recved: check for overflow and warn about too big values

This commit is contained in:
Jonas Rabenstein 2018-10-11 00:40:26 +02:00 committed by Simon Goldschmidt
parent 368128a647
commit ebb0dc14a7

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@ -966,6 +966,7 @@ void
tcp_recved(struct tcp_pcb *pcb, u16_t len)
{
u32_t wnd_inflation;
tcpwnd_size_t rcv_wnd;
LWIP_ASSERT_CORE_LOCKED();
@ -975,10 +976,8 @@ tcp_recved(struct tcp_pcb *pcb, u16_t len)
LWIP_ASSERT("don't call tcp_recved for listen-pcbs",
pcb->state != LISTEN);
pcb->rcv_wnd = (tcpwnd_size_t)(pcb->rcv_wnd + len);
if (pcb->rcv_wnd > TCP_WND_MAX(pcb)) {
pcb->rcv_wnd = TCP_WND_MAX(pcb);
} else if (pcb->rcv_wnd == 0) {
rcv_wnd = pcb->rcv_wnd + len;
if (rcv_wnd < pcb->rcv_wnd || (len != 0 && rcv_wnd == pcb->rcv_wnd)) {
/* rcv_wnd overflowed */
if (TCP_STATE_IS_CLOSING(pcb->state)) {
/* In passive close, we allow this, since the FIN bit is added to rcv_wnd
@ -988,6 +987,12 @@ tcp_recved(struct tcp_pcb *pcb, u16_t len)
} else {
LWIP_ASSERT("tcp_recved: len wrapped rcv_wnd\n", 0);
}
} else if (rcv_wnd <= TCP_WND_MAX(pcb)) {
pcb->rcv_wnd = rcv_wnd;
} else {
LWIP_ASSERT("tcp_recved: len overflowed TCP_WND_MAX",
rcv_wnd <= TCP_WND_MAX(pcb));
pcb->rcv_wnd = TCP_WND_MAX(pcb);
}
wnd_inflation = tcp_update_rcv_ann_wnd(pcb);