mirror/lwip
1
0
Fork 0
mirror of https://github.com/lwip-tcpip/lwip.git synced 2024-07-07 21:38:50 +00:00
Code Issues Packages Projects Releases Wiki Activity

tcp_write: moved initial checks to an own static function for clarity

Browse Source
This commit is contained in:
goldsimon 2010-03-20 12:08:07 +00:00
parent 75bb43698c
commit 57594ad7b6
1 changed files with 54 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

93
src/core/tcp_out.c
View File

@ -273,6 +273,56 @@ tcp_seg_add_chksum(u16_t chksum, u16_t len, u16_t *seg_chksum,
}
#endif /* TCP_CHECKSUM_ON_COPY */
/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
*
* @param pcb the tcp pcb to check for
* @param len length of data to send (checked agains snd_buf)
* @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
*/
static err_t
tcp_write_checks(struct tcp_pcb *pcb, u16_t len)
{
/* connection is in invalid state for data transmission? */
if ((pcb->state != ESTABLISHED) &&
(pcb->state != CLOSE_WAIT) &&
(pcb->state != SYN_SENT) &&
(pcb->state != SYN_RCVD)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
return ERR_CONN;
} else if (len == 0) {
return ERR_OK;
}
/* fail on too much data */
if (len > pcb->snd_buf) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
len, pcb->snd_buf));
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
}
LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
/* If total number of pbufs on the unsent/unacked queues exceeds the
* configured maximum, return an error */
/* check for configured max queuelen and possible overflow */
if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n",
pcb->snd_queuelen, TCP_SND_QUEUELEN));
TCP_STATS_INC(tcp.memerr);
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
}
if (pcb->snd_queuelen != 0) {
LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
pcb->unacked != NULL || pcb->unsent != NULL);
} else {
LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
pcb->unacked == NULL && pcb->unsent == NULL);
}
return ERR_OK;
}
/**
* Write data for sending (but does not send it immediately).
*
@ -307,6 +357,7 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
u8_t concat_chksum_swapped = 0;
u16_t concat_chksummed = 0;
#endif /* TCP_CHECKSUM_ON_COPY */
err_t err;
#if LWIP_NETIF_TX_SINGLE_PBUF
/* Always copy to try to create single pbufs for TX */
@ -315,50 +366,14 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
(void *)pcb, arg, len, (u16_t)apiflags));
/* connection is in invalid state for data transmission? */
if ((pcb->state != ESTABLISHED) &&
(pcb->state != CLOSE_WAIT) &&
(pcb->state != SYN_SENT) &&
(pcb->state != SYN_RCVD)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
return ERR_CONN;
} else if (len == 0) {
return ERR_OK;
}
LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, arg=%p, len=%"U16_F", apiflags=%"U16_F")\n",
(void *)pcb, arg, len, (u16_t)apiflags));
LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)",
arg != NULL, return ERR_ARG;);
/* fail on too much data */
if (len > pcb->snd_buf) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
len, pcb->snd_buf));
pcb->flags |= TF_NAGLEMEMERR;
return ERR_MEM;
err = tcp_write_checks(pcb, len);
if (err != ERR_OK) {
return err;
}
LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
/* If total number of pbufs on the unsent/unacked queues exceeds the
* configured maximum, return an error */
queuelen = pcb->snd_queuelen;
/* check for configured max queuelen and possible overflow */
if ((queuelen >= TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: 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) {
LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
pcb->unacked != NULL || pcb->unsent != NULL);
} else {
LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
pcb->unacked == NULL && pcb->unsent == NULL);
}
#if LWIP_TCP_TIMESTAMPS
if ((pcb->flags & TF_TIMESTAMP)) {