Fixed bug #20287: tcp_output_nagle sends too early. This fixes the nagle algorithm; nagle now also works for all raw API applications and has to be explicitly disabled with 'tcp_pcb->flags |= TF_NODELAY'

This commit is contained in:
goldsimon 2007-11-21 17:59:03 +00:00
parent c31b405af6
commit dc515c7ad3
4 changed files with 43 additions and 9 deletions

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@ -486,6 +486,11 @@ HISTORY
++ Bug fixes:
2007-11-21 Simon Goldschmidt
* tcp.h, tcp_out.c, api_msg.c: Fixed bug #20287: tcp_output_nagle sends too early
Fixed the nagle algorithm; nagle now also works for all raw API applications
and has to be explicitly disabled with 'tcp_pcb->flags |= TF_NODELAY'
2007-11-12 Frédéric Bernon
* sockets.c, api.h, api_lib.c, api_msg.h, api_msg.c: Fixed bug #20900. Now, most
of the netconn_peer and netconn_addr processing is done inside tcpip_thread

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@ -819,6 +819,9 @@ do_writemore(struct netconn *conn)
API_EVENT(conn, NETCONN_EVT_SENDMINUS, len);
}
} else if (err == ERR_MEM) {
/* tcp_enqueue returned ERR_MEM, try tcp_output anyway */
err = tcp_output(conn->pcb.tcp);
#if LWIP_TCPIP_CORE_LOCKING
conn->write_delayed = 1;
#endif

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@ -147,6 +147,7 @@ tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len,
/* fail on too much data */
if (len > pcb->snd_buf) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n", len, pcb->snd_buf));
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
}
left = len;
@ -165,6 +166,7 @@ tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len,
if ((queuelen >= TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue: too long queue %"U16_F" (max %"U16_F")\n", queuelen, TCP_SND_QUEUELEN));
TCP_STATS_INC(tcp.memerr);
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
}
if (queuelen != 0) {
@ -361,6 +363,9 @@ tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len,
if ((flags & TCP_SYN) || (flags & TCP_FIN)) {
++len;
}
if (flags & TCP_FIN) {
pcb->flags |= TF_FIN;
}
pcb->snd_lbb += len;
pcb->snd_buf -= len;
@ -381,6 +386,7 @@ tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len,
return ERR_OK;
memerr:
pcb->flags |= TF_NAGLEMEMERR;
TCP_STATS_INC(tcp.memerr);
if (queue != NULL) {
@ -503,6 +509,18 @@ tcp_output(struct tcp_pcb *pcb)
/* data available and window allows it to be sent? */
while (seg != NULL &&
ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
LWIP_ASSERT("RST not expected here!", (TCPH_FLAGS(seg->tcphdr) & TCP_RST) == 0);
/* Stop sending if the nagle algorithm would prevent it
* Don't stop:
* - if tcp_enqueue had a memory error before (prevent delayed ACK timeout) or
* - if FIN was already enqueued for this PCB (SYN is always alone in a segment -
* either seg->next != NULL or pcb->unacked == NULL;
* RST is no sent using tcp_enqueue/tcp_output.
*/
if((tcp_do_output_nagle(pcb) == 0) &&
((pcb->flags & (TF_NAGLEMEMERR | TF_FIN)) == 0)){
break;
}
#if TCP_CWND_DEBUG
LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"U16_F", cwnd %"U16_F", wnd %"U32_F", effwnd %"U32_F", seq %"U32_F", ack %"U32_F", i %"S16_F"\n",
pcb->snd_wnd, pcb->cwnd, wnd,
@ -552,6 +570,7 @@ tcp_output(struct tcp_pcb *pcb)
}
seg = pcb->unsent;
}
pcb->flags &= ~TF_NAGLEMEMERR;
return ERR_OK;
}

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@ -122,10 +122,12 @@ void tcp_rexmit_rto (struct tcp_pcb *pcb);
* previously transmitted data on the connection remains
* unacknowledged.
*/
#define tcp_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
#define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
((tpcb)->flags & TF_NODELAY) || \
(((tpcb)->unsent != NULL) && ((tpcb)->unsent->next != NULL))) ? \
tcp_output(tpcb) : ERR_OK)
1 : 0)
#define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)
/** This returns a TCP header option for MSS in an u32_t */
#define TCP_BUILD_MSS_OPTION() htonl(((u32_t)2 << 24) | \
@ -239,6 +241,12 @@ enum tcp_state {
TIME_WAIT = 10
};
/** Flags used on input processing, not on pcb->flags
*/
#define TF_RESET (u8_t)0x08U /* Connection was reset. */
#define TF_CLOSED (u8_t)0x10U /* Connection was sucessfully closed. */
#define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */
/**
* members common to struct tcp_pcb and struct tcp_listen_pcb
*/
@ -261,13 +269,12 @@ struct tcp_pcb {
u16_t remote_port;
u8_t flags;
#define TF_ACK_DELAY (u8_t)0x01U /* Delayed ACK. */
#define TF_ACK_NOW (u8_t)0x02U /* Immediate ACK. */
#define TF_INFR (u8_t)0x04U /* In fast recovery. */
#define TF_RESET (u8_t)0x08U /* Connection was reset. */
#define TF_CLOSED (u8_t)0x10U /* Connection was sucessfully closed. */
#define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */
#define TF_NODELAY (u8_t)0x40U /* Disable Nagle algorithm */
#define TF_ACK_DELAY (u8_t)0x01U /* Delayed ACK. */
#define TF_ACK_NOW (u8_t)0x02U /* Immediate ACK. */
#define TF_INFR (u8_t)0x04U /* In fast recovery. */
#define TF_FIN (u8_t)0x20U /* Connection was closed locally (FIN segment enqueued). */
#define TF_NODELAY (u8_t)0x40U /* Disable Nagle algorithm */
#define TF_NAGLEMEMERR (u8_t)0x80U /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
/* the rest of the fields are in host byte order
as we have to do some math with them */