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tcp_out: combine the tx path of the 4 direct tx functions

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tcp_rst, tcp_send_empty_ack, tcp_keepalive and tcp_zero_window_probe
all execute the same instructions to send a segment pbuf.
Combined into tcp_output_control_segment().
This commit is contained in:
goldsimon 2018-01-30 21:50:41 +01:00
parent 9128a51944
commit 424c33bcb7
1 changed files with 44 additions and 74 deletions
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118
src/core/tcp_out.c
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@ -1781,6 +1781,46 @@ tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen,
return p;
}
/** Output a control segment pbuf to IP.
*
* Called from tcp_rst, tcp_send_empty_ack, tcp_keepalive and tcp_zero_window_probe,
* this function combines selecting a netif for transmission, generating the tcp
* header checksum and calling ip_output_if while handling netif hints and stats.
*/
static err_t
tcp_output_control_segment(const struct tcp_pcb *pcb, struct pbuf *p,
const ip_addr_t *src, const ip_addr_t *dst)
{
err_t err;
struct netif *netif = tcp_route(pcb, src, dst);
if (netif == NULL) {
err = ERR_RTE;
} else {
u8_t ttl, tos;
#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,
src, dst);
}
#endif
if (pcb != NULL) {
NETIF_SET_HINTS(netif, &(pcb->netif_hints));
ttl = pcb->ttl;
tos = pcb->tos;
} else {
/* Send output with hardcoded TTL/HL since we have no access to the pcb */
ttl = TCP_TTL;
tos = 0;
}
TCP_STATS_INC(tcp.xmit);
err = ip_output_if(p, src, dst, ttl, tos, IP_PROTO_TCP, netif);
NETIF_RESET_HINTS(netif);
}
pbuf_free(p);
return err;
}
/**
* Send a TCP RESET packet (empty segment with RST flag set) either to
* abort a connection or to show that there is no matching local connection
@ -1808,7 +1848,6 @@ 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 netif *netif;
u16_t wnd;
#if LWIP_WND_SCALE
@ -1824,22 +1863,9 @@ tcp_rst(const struct tcp_pcb *pcb, u32_t seqno, u32_t ackno,
return;
}
TCP_STATS_INC(tcp.xmit);
MIB2_STATS_INC(mib2.tcpoutrsts);
netif = tcp_route(pcb, local_ip, remote_ip);
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);
}
#endif
/* Send output with hardcoded TTL/HL since we have no access to the pcb */
ip_output_if(p, local_ip, remote_ip, TCP_TTL, 0, IP_PROTO_TCP, netif);
}
pbuf_free(p);
tcp_output_control_segment(pcb, p, local_ip, remote_ip);
LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_rst: seqno %"U32_F" ackno %"U32_F".\n", seqno, ackno));
}
@ -1854,7 +1880,6 @@ tcp_send_empty_ack(struct tcp_pcb *pcb)
err_t err;
struct pbuf *p;
u8_t optlen = 0;
struct netif *netif;
#if CHECKSUM_GEN_TCP || LWIP_TCP_TIMESTAMPS || LWIP_TCP_SACK_OUT
struct tcp_hdr *tcphdr;
#if LWIP_TCP_TIMESTAMPS || LWIP_TCP_SACK_OUT
@ -1915,23 +1940,7 @@ tcp_send_empty_ack(struct tcp_pcb *pcb)
}
#endif
netif = tcp_route(pcb, &pcb->local_ip, &pcb->remote_ip);
if (netif == NULL) {
err = ERR_RTE;
} else {
#if CHECKSUM_GEN_TCP
IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_TCP) {
tcphdr->chksum = ip_chksum_pseudo(p, IP_PROTO_TCP, p->tot_len,
&pcb->local_ip, &pcb->remote_ip);
}
#endif
NETIF_SET_HINTS(netif, &(pcb->netif_hints));
err = ip_output_if(p, &pcb->local_ip, &pcb->remote_ip,
pcb->ttl, pcb->tos, IP_PROTO_TCP, netif);
NETIF_RESET_HINTS(netif);
}
pbuf_free(p);
err = tcp_output_control_segment(pcb, p, &pcb->local_ip, &pcb->remote_ip);
if (err != ERR_OK) {
/* let tcp_fasttmr retry sending this ACK */
tcp_set_flags(pcb, TF_ACK_DELAY | TF_ACK_NOW);
@ -1956,7 +1965,6 @@ tcp_keepalive(struct tcp_pcb *pcb)
{
err_t err;
struct pbuf *p;
struct netif *netif;
LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: sending KEEPALIVE probe to "));
ip_addr_debug_print_val(TCP_DEBUG, pcb->remote_ip);
@ -1971,25 +1979,7 @@ tcp_keepalive(struct tcp_pcb *pcb)
("tcp_keepalive: could not allocate memory for pbuf\n"));
return ERR_MEM;
}
netif = tcp_route(pcb, &pcb->local_ip, &pcb->remote_ip);
if (netif == NULL) {
err = ERR_RTE;
} else {
#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,
&pcb->local_ip, &pcb->remote_ip);
}
#endif /* CHECKSUM_GEN_TCP */
TCP_STATS_INC(tcp.xmit);
/* Send output to IP */
NETIF_SET_HINTS(netif, &(pcb->netif_hints));
err = ip_output_if(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP, netif);
NETIF_RESET_HINTS(netif);
}
pbuf_free(p);
err = tcp_output_control_segment(pcb, p, &pcb->local_ip, &pcb->remote_ip);
LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: seqno %"U32_F" ackno %"U32_F" err %d.\n",
pcb->snd_nxt - 1, pcb->rcv_nxt, (int)err));
@ -2014,7 +2004,6 @@ tcp_zero_window_probe(struct tcp_pcb *pcb)
u16_t len;
u8_t is_fin;
u32_t snd_nxt;
struct netif *netif;
LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: sending ZERO WINDOW probe to "));
ip_addr_debug_print_val(TCP_DEBUG, pcb->remote_ip);
@ -2069,26 +2058,7 @@ tcp_zero_window_probe(struct tcp_pcb *pcb)
pcb->snd_nxt = snd_nxt;
}
netif = tcp_route(pcb, &pcb->local_ip, &pcb->remote_ip);
if (netif == NULL) {
err = ERR_RTE;
} else {
#if CHECKSUM_GEN_TCP
IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_TCP) {
tcphdr->chksum = ip_chksum_pseudo(p, IP_PROTO_TCP, p->tot_len,
&pcb->local_ip, &pcb->remote_ip);
}
#endif
TCP_STATS_INC(tcp.xmit);
/* Send output to IP */
NETIF_SET_HINTS(netif, &(pcb->netif_hints));
err = ip_output_if(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
0, IP_PROTO_TCP, netif);
NETIF_RESET_HINTS(netif);
}
pbuf_free(p);
err = tcp_output_control_segment(pcb, p, &pcb->local_ip, &pcb->remote_ip);
LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: seqno %"U32_F
" ackno %"U32_F" err %d.\n",