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Fixed bug #47485 (tcp_close() should not fail on memory error) by retrying to send FIN from tcp_fasttmr

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This commit is contained in:
goldsimon 2017-02-10 09:42:38 +01:00
parent 82711e069c
commit bc07fd9db5
3 changed files with 41 additions and 14 deletions
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5
CHANGELOG
View File

@ -5,7 +5,10 @@ HISTORY
* [Enter new changes just after this line - do not remove this line]
++ New features:
2017-02-10: Simon Goldschmidt
* tcp_close does not fail on memory error (instead, FIN is sent from tcp_tmr)
2017-02-04: David van Moolenbroek
- IPv6 scopes support

39
src/core/tcp.c
View File

@ -132,6 +132,8 @@ static u8_t tcp_timer;
static u8_t tcp_timer_ctr;
static u16_t tcp_new_port(void);
static err_t tcp_close_shutdown_fin(struct tcp_pcb *pcb);
/**
* Initialize this module.
*/
@ -258,8 +260,6 @@ tcp_backlog_accepted(struct tcp_pcb* pcb)
static err_t
tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
{
err_t err;
if (rst_on_unacked_data && ((pcb->state == ESTABLISHED) || (pcb->state == CLOSE_WAIT))) {
if ((pcb->refused_data != NULL) || (pcb->rcv_wnd != TCP_WND_MAX(pcb))) {
/* Not all data received by application, send RST to tell the remote
@ -290,6 +290,8 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
}
}
/* - states which free the pcb are handled here,
- states which send FIN and change state are handled in tcp_close_shutdown_impl() */
switch (pcb->state) {
case CLOSED:
/* Closing a pcb in the CLOSED state might seem erroneous,
@ -299,27 +301,34 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
* or for a pcb that has been used and then entered the CLOSED state
* is erroneous, but this should never happen as the pcb has in those cases
* been freed, and so any remaining handles are bogus. */
err = ERR_OK;
if (pcb->local_port != 0) {
TCP_RMV(&tcp_bound_pcbs, pcb);
}
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case LISTEN:
err = ERR_OK;
tcp_listen_closed(pcb);
tcp_pcb_remove(&tcp_listen_pcbs.pcbs, pcb);
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
pcb = NULL;
break;
case SYN_SENT:
err = ERR_OK;
TCP_PCB_REMOVE_ACTIVE(pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
MIB2_STATS_INC(mib2.tcpattemptfails);
break;
default:
return tcp_close_shutdown_fin(pcb);
}
return ERR_OK;
}
static err_t
tcp_close_shutdown_fin(struct tcp_pcb *pcb)
{
err_t err;
LWIP_ASSERT("pcb != NULL", pcb != NULL);
switch (pcb->state) {
case SYN_RCVD:
err = tcp_send_fin(pcb);
if (err == ERR_OK) {
@ -344,18 +353,20 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
break;
default:
/* Has already been closed, do nothing. */
err = ERR_OK;
pcb = NULL;
return ERR_OK;
break;
}
if (pcb != NULL && err == ERR_OK) {
if (err == ERR_OK) {
/* To ensure all data has been sent when tcp_close returns, we have
to make sure tcp_output doesn't fail.
Since we don't really have to ensure all data has been sent when tcp_close
returns (unsent data is sent from tcp timer functions, also), we don't care
for the return value of tcp_output for now. */
tcp_output(pcb);
} else if (err == ERR_MEM) {
/* Mark this pcb for closing. Closing is retried from tcp_tmr. */
pcb->flags |= TF_CLOSEPEND;
}
return err;
}
@ -1276,6 +1287,12 @@ tcp_fasttmr_start:
tcp_output(pcb);
pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
}
/* send pending FIN */
if (pcb->flags & TF_CLOSEPEND) {
LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: pending FIN\n"));
pcb->flags &= ~(TF_CLOSEPEND);
tcp_close_shutdown_fin(pcb);
}
next = pcb->next;

11
src/include/lwip/tcp.h
View File

@ -145,7 +145,7 @@ typedef u32_t tcpwnd_size_t;
typedef u16_t tcpwnd_size_t;
#endif
#if LWIP_WND_SCALE || TCP_LISTEN_BACKLOG
#if LWIP_WND_SCALE || TCP_LISTEN_BACKLOG || LWIP_TCP_TIMESTAMPS
typedef u16_t tcpflags_t;
#else
typedef u8_t tcpflags_t;
@ -210,7 +210,7 @@ struct tcp_pcb {
#define TF_ACK_DELAY 0x01U /* Delayed ACK. */
#define TF_ACK_NOW 0x02U /* Immediate ACK. */
#define TF_INFR 0x04U /* In fast recovery. */
#define TF_TIMESTAMP 0x08U /* Timestamp option enabled */
#define TF_CLOSEPEND 0x08U /* If this is set, tcp_close failed to enqueue the FIN (retried in tcp_tmr) */
#define TF_RXCLOSED 0x10U /* rx closed by tcp_shutdown */
#define TF_FIN 0x20U /* Connection was closed locally (FIN segment enqueued). */
#define TF_NODELAY 0x40U /* Disable Nagle algorithm */
@ -220,6 +220,9 @@ struct tcp_pcb {
#endif
#if TCP_LISTEN_BACKLOG
#define TF_BACKLOGPEND 0x0200U /* If this is set, a connection pcb has increased the backlog on its listener */
#endif
#if LWIP_TCP_TIMESTAMPS
#define TF_TIMESTAMP 0x0400U /* Timestamp option enabled */
#endif
/* the rest of the fields are in host byte order
@ -358,7 +361,11 @@ void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept);
#endif /* LWIP_CALLBACK_API */
void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval);
#if LWIP_TCP_TIMESTAMPS
#define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss)
#else /* LWIP_TCP_TIMESTAMPS */
#define tcp_mss(pcb) ((pcb)->mss)
#endif /* LWIP_TCP_TIMESTAMPS */
#define tcp_sndbuf(pcb) (TCPWND16((pcb)->snd_buf))
#define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen)
/** @ingroup tcp_raw */