mirror/lwip
1
0
Fork 0
mirror of https://github.com/lwip-tcpip/lwip.git synced 2024-07-16 17:57:25 +00:00
Code Issues Packages Projects Releases Wiki Activity

tcp_out: make tcp_output_alloc_header generic enough for tcp_rst

Browse Source
This commit is contained in:
goldsimon 2018-01-30 21:46:48 +01:00
parent 1570dd8ad1
commit 9128a51944
1 changed files with 38 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
src/core/tcp_out.c
View File

@ -1734,6 +1734,29 @@ tcp_rexmit_fast(struct tcp_pcb *pcb)
}
}
static struct pbuf *
tcp_output_alloc_header_common(u32_t ackno, u16_t optlen, u16_t datalen,
u32_t seqno_be /* already in network byte order */,
u16_t src_port, u16_t dst_port, u8_t flags, u16_t wnd)
{
struct tcp_hdr *tcphdr;
struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM);
if (p != NULL) {
LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
(p->len >= TCP_HLEN + optlen));
tcphdr = (struct tcp_hdr *)p->payload;
tcphdr->src = lwip_htons(src_port);
tcphdr->dest = lwip_htons(dst_port);
tcphdr->seqno = seqno_be;
tcphdr->ackno = lwip_htonl(ackno);
TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), flags);
tcphdr->wnd = lwip_htons(wnd);
tcphdr->chksum = 0;
tcphdr->urgp = 0;
}
return p;
}
/** Allocate a pbuf and create a tcphdr at p->payload, used for output
* functions other than the default tcp_output -> tcp_output_segment
* (e.g. tcp_send_empty_ack, etc.)
@ -1748,21 +1771,10 @@ static struct pbuf *
tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen,
u32_t seqno_be /* already in network byte order */)
{
struct tcp_hdr *tcphdr;
struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM);
struct pbuf *p = tcp_output_alloc_header_common(pcb->rcv_nxt, optlen, datalen,
seqno_be, pcb->local_port, pcb->remote_port, TCP_ACK,
TCPWND_MIN16(RCV_WND_SCALE(pcb, pcb->rcv_ann_wnd)));
if (p != NULL) {
LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
(p->len >= TCP_HLEN + optlen));
tcphdr = (struct tcp_hdr *)p->payload;
tcphdr->src = lwip_htons(pcb->local_port);
tcphdr->dest = lwip_htons(pcb->remote_port);
tcphdr->seqno = seqno_be;
tcphdr->ackno = lwip_htonl(pcb->rcv_nxt);
TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), TCP_ACK);
tcphdr->wnd = lwip_htons(TCPWND_MIN16(RCV_WND_SCALE(pcb, pcb->rcv_ann_wnd)));
tcphdr->chksum = 0;
tcphdr->urgp = 0;
/* If we're sending a packet, update the announced right window edge */
pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
}
@ -1796,29 +1808,21 @@ tcp_rst(const struct tcp_pcb *pcb, u32_t seqno, u32_t ackno,
u16_t local_port, u16_t remote_port)
{
struct pbuf *p;
struct tcp_hdr *tcphdr;
struct netif *netif;
p = pbuf_alloc(PBUF_IP, TCP_HLEN, PBUF_RAM);
u16_t wnd;
#if LWIP_WND_SCALE
wnd = PP_HTONS(((TCP_WND >> TCP_RCV_SCALE) & 0xFFFF));
#else
wnd = PP_HTONS(TCP_WND);
#endif
p = tcp_output_alloc_header_common(ackno, 0, 0, lwip_htonl(seqno), local_port,
remote_port, TCP_RST | TCP_ACK, wnd);
if (p == NULL) {
LWIP_DEBUGF(TCP_DEBUG, ("tcp_rst: could not allocate memory for pbuf\n"));
return;
}
LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
(p->len >= sizeof(struct tcp_hdr)));
tcphdr = (struct tcp_hdr *)p->payload;
tcphdr->src = lwip_htons(local_port);
tcphdr->dest = lwip_htons(remote_port);
tcphdr->seqno = lwip_htonl(seqno);
tcphdr->ackno = lwip_htonl(ackno);
TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN / 4, TCP_RST | TCP_ACK);
#if LWIP_WND_SCALE
tcphdr->wnd = PP_HTONS(((TCP_WND >> TCP_RCV_SCALE) & 0xFFFF));
#else
tcphdr->wnd = PP_HTONS(TCP_WND);
#endif
tcphdr->chksum = 0;
tcphdr->urgp = 0;
TCP_STATS_INC(tcp.xmit);
MIB2_STATS_INC(mib2.tcpoutrsts);
@ -1827,6 +1831,7 @@ tcp_rst(const struct tcp_pcb *pcb, u32_t seqno, u32_t ackno,
if (netif != NULL) {
#if CHECKSUM_GEN_TCP
IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_TCP) {
struct tcp_hdr *tcphdr = (struct tcp_hdr *)p->payload;
tcphdr->chksum = ip_chksum_pseudo(p, IP_PROTO_TCP, p->tot_len,
local_ip, remote_ip);
}
@ -2020,7 +2025,7 @@ tcp_zero_window_probe(struct tcp_pcb *pcb)
" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
tcp_ticks, pcb->tmr, (u16_t)pcb->keep_cnt_sent));
/* Only consider unsent, persist timer should be off when there data is in-flight */
/* Only consider unsent, persist timer should be off when there is data in-flight */
seg = pcb->unsent;
if (seg == NULL) {
/* Not expected, persist timer should be off when the send buffer is empty */