lwip: fix the assertion in tcp_pcb_purge()

Fix the assertion in tcp_pcb_purge().
This commit is contained in:
Liu Zhi Fu 2018-06-29 13:40:20 +08:00
parent e56bfadc58
commit 86a6c21e79
6 changed files with 149 additions and 57 deletions

View File

@ -407,9 +407,9 @@ netconn_accept(struct netconn *conn, struct netconn **new_conn)
#if TCP_LISTEN_BACKLOG
/* Let the stack know that we have accepted the connection. */
API_MSG_VAR_ALLOC_DONTFAIL(msg);
API_MSG_VAR_REF(msg).msg.conn = conn;
/* don't care for the return value of lwip_netconn_do_recv */
TCPIP_APIMSG_NOERR(&API_MSG_VAR_REF(msg), lwip_netconn_do_recv);
API_MSG_VAR_REF(msg).msg.conn = newconn;
/* don't care for the return value of lwip_netconn_do_accepted */
TCPIP_APIMSG_NOERR(&API_MSG_VAR_REF(msg), lwip_netconn_do_accepted);
API_MSG_VAR_FREE(msg);
#endif /* TCP_LISTEN_BACKLOG */

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@ -536,6 +536,9 @@ accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
to the application thread */
newconn->last_err = err;
/* handle backlog counter */
tcp_backlog_delayed(newpcb);
if (sys_mbox_trypost(&conn->acceptmbox, newconn) != ERR_OK) {
ESP_STATS_DROP_INC(esp.acceptmbox_post_fail);
/* When returning != ERR_OK, the pcb is aborted in tcp_process(),
@ -1503,12 +1506,6 @@ lwip_netconn_do_recv(void *m)
msg->err = ERR_OK;
if (msg->conn->pcb.tcp != NULL) {
if (NETCONNTYPE_GROUP(msg->conn->type) == NETCONN_TCP) {
#if TCP_LISTEN_BACKLOG
if (msg->conn->pcb.tcp->state == LISTEN) {
tcp_accepted(msg->conn->pcb.tcp);
} else
#endif /* TCP_LISTEN_BACKLOG */
{
u32_t remaining = msg->msg.r.len;
do {
u16_t recved = (remaining > 0xffff) ? 0xffff : (u16_t)remaining;
@ -1517,9 +1514,29 @@ lwip_netconn_do_recv(void *m)
} while (remaining != 0);
}
}
TCPIP_APIMSG_ACK(msg);
}
#if TCP_LISTEN_BACKLOG
/** Indicate that a TCP pcb has been accepted
* Called from netconn_accept
*
* @param m the api_msg pointing to the connection
*/
void
lwip_netconn_do_accepted(void *m)
{
struct api_msg_msg *msg = (struct api_msg_msg *)m;
msg->err = ERR_OK;
if (msg->conn->pcb.tcp != NULL) {
if (NETCONNTYPE_GROUP(msg->conn->type) == NETCONN_TCP) {
tcp_backlog_accepted(msg->conn->pcb.tcp);
}
}
TCPIP_APIMSG_ACK(msg);
}
#endif /* TCP_LISTEN_BACKLOG */
/**
* See if more data needs to be written from a previous call to netconn_write.

View File

@ -149,6 +149,22 @@ tcp_tmr(void)
}
}
#if LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG
/** Called when a listen pcb is closed. Iterates one pcb list and removes the
* closed listener pcb from pcb->listener if matching.
*/
static void
tcp_remove_listener(struct tcp_pcb *list, struct tcp_pcb_listen *lpcb)
{
struct tcp_pcb *pcb;
for (pcb = list; pcb != NULL; pcb = pcb->next) {
if (pcb->listener == lpcb) {
pcb->listener = NULL;
}
}
}
#endif
void
tcp_set_fin_wait_1(struct tcp_pcb *pcb)
{
@ -158,6 +174,70 @@ tcp_set_fin_wait_1(struct tcp_pcb *pcb)
#endif
}
/** Called when a listen pcb is closed. Iterates all pcb lists and removes the
* closed listener pcb from pcb->listener if matching.
*/
static void
tcp_listen_closed(struct tcp_pcb *pcb)
{
#if LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG
size_t i;
LWIP_ASSERT("pcb != NULL", pcb != NULL);
LWIP_ASSERT("pcb->state == LISTEN", pcb->state == LISTEN);
for (i = 1; i < LWIP_ARRAYSIZE(tcp_pcb_lists); i++) {
tcp_remove_listener(*tcp_pcb_lists[i], (struct tcp_pcb_listen *)pcb);
}
#endif
LWIP_UNUSED_ARG(pcb);
}
#if TCP_LISTEN_BACKLOG
/** @ingroup tcp_raw
* Delay accepting a connection in respect to the listen backlog:
* the number of outstanding connections is increased until
* tcp_backlog_accepted() is called.
*
* ATTENTION: the caller is responsible for calling tcp_backlog_accepted()
* or else the backlog feature will get out of sync!
*
* @param pcb the connection pcb which is not fully accepted yet
*/
void
tcp_backlog_delayed(struct tcp_pcb *pcb)
{
LWIP_ASSERT("pcb != NULL", pcb != NULL);
if ((pcb->flags & TF_BACKLOGPEND) == 0) {
if (pcb->listener != NULL) {
pcb->listener->accepts_pending++;
LWIP_ASSERT("accepts_pending != 0", pcb->listener->accepts_pending != 0);
pcb->flags |= TF_BACKLOGPEND;
}
}
}
/** @ingroup tcp_raw
* A delayed-accept a connection is accepted (or closed/aborted): decreases
* the number of outstanding connections after calling tcp_backlog_delayed().
*
* ATTENTION: the caller is responsible for calling tcp_backlog_accepted()
* or else the backlog feature will get out of sync!
*
* @param pcb the connection pcb which is now fully accepted (or closed/aborted)
*/
void
tcp_backlog_accepted(struct tcp_pcb *pcb)
{
LWIP_ASSERT("pcb != NULL", pcb != NULL);
if ((pcb->flags & TF_BACKLOGPEND) != 0) {
if (pcb->listener != NULL) {
LWIP_ASSERT("accepts_pending != 0", pcb->listener->accepts_pending != 0);
pcb->listener->accepts_pending--;
pcb->flags &= ~TF_BACKLOGPEND;
}
}
}
#endif /* TCP_LISTEN_BACKLOG */
/**
* Closes the TX side of a connection held by the PCB.
* For tcp_close(), a RST is sent if the application didn't receive all data
@ -227,6 +307,7 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
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;
@ -241,6 +322,7 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
case SYN_RCVD:
err = tcp_send_fin(pcb);
if (err == ERR_OK) {
tcp_backlog_accepted(pcb);
MIB2_STATS_INC(mib2.tcpattemptfails);
tcp_set_fin_wait_1(pcb);
}
@ -408,6 +490,7 @@ tcp_abandon(struct tcp_pcb *pcb, int reset)
pcb->ooseq = NULL;
}
#endif /* TCP_QUEUE_OOSEQ */
tcp_backlog_accepted(pcb);
if (send_rst) {
LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
tcp_rst(seqno, ackno, &pcb->local_ip, &pcb->remote_ip, local_port, pcb->remote_port);
@ -1747,39 +1830,7 @@ tcp_pcb_purge(struct tcp_pcb *pcb)
LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
#if TCP_LISTEN_BACKLOG
if (pcb->state == SYN_RCVD) {
/* Need to find the corresponding listen_pcb and decrease its accepts_pending */
struct tcp_pcb_listen *lpcb;
/*
* The official LWIP will assert the system if tcp_listen_pcbs.listen_pcbs is NULL, it's a bug.
*
* Considering following scenario:
* 1. On TCP server side, one of TCP pcb is in SYNC_RECV state and is waiting for TCP ACK from TCP client.
* 2. The TCP server is closed by application, which causes the tcp_listen_pcbs.listen_pcbs to become NULL.
* 3. When SYNC_RECV state timeout (20s by default), tcp_pcb_purge() is called in tcp_slowtmr(), it asserts
* the system.
* This is a normal scenario, should NOT assert the system. So just remove it.
*
*/
if (tcp_listen_pcbs.listen_pcbs) {
for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
if ((lpcb->local_port == pcb->local_port) &&
(IP_IS_V6_VAL(pcb->local_ip) == IP_IS_V6_VAL(lpcb->local_ip)) &&
(ip_addr_isany(&lpcb->local_ip) ||
ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
/* port and address of the listen pcb match the timed-out pcb */
LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
lpcb->accepts_pending > 0);
lpcb->accepts_pending--;
break;
}
}
}
}
#endif /* TCP_LISTEN_BACKLOG */
tcp_backlog_accepted(pcb);
if (pcb->refused_data != NULL) {
LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));

View File

@ -568,6 +568,7 @@ tcp_listen_input(struct tcp_pcb_listen *pcb)
}
#if TCP_LISTEN_BACKLOG
pcb->accepts_pending++;
npcb->flags |= TF_BACKLOGPEND;
#endif /* TCP_LISTEN_BACKLOG */
/* Set up the new PCB. */
ip_addr_copy(npcb->local_ip, *ip_current_dest_addr());
@ -582,6 +583,10 @@ tcp_listen_input(struct tcp_pcb_listen *pcb)
#if LWIP_CALLBACK_API
npcb->accept = pcb->accept;
#endif /* LWIP_CALLBACK_API */
#if LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG
npcb->listener = pcb;
#endif
/* inherit socket options */
npcb->so_options = pcb->so_options & SOF_INHERITED;
/* Register the new PCB so that we can begin receiving segments
@ -785,11 +790,19 @@ tcp_process(struct tcp_pcb *pcb)
if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) {
pcb->state = ESTABLISHED;
LWIP_DEBUGF(TCP_DEBUG, ("TCP connection established %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
#if LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG
#if LWIP_CALLBACK_API
LWIP_ASSERT("pcb->accept != NULL", pcb->accept != NULL);
#endif
if (pcb->listener == NULL) {
err = ERR_VAL;
} else {
#endif
tcp_backlog_accepted(pcb);
/* Call the accept function. */
TCP_EVENT_ACCEPT(pcb, ERR_OK, err);
}
if (err != ERR_OK) {
/* If the accept function returns with an error, we abort
* the connection. */

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@ -232,6 +232,9 @@ void lwip_netconn_do_disconnect (void *m);
void lwip_netconn_do_listen (void *m);
void lwip_netconn_do_send (void *m);
void lwip_netconn_do_recv (void *m);
#if TCP_LISTEN_BACKLOG
void lwip_netconn_do_accepted (void *m);
#endif
void lwip_netconn_do_write (void *m);
void lwip_netconn_do_getaddr (void *m);
void lwip_netconn_do_close (void *m);

View File

@ -138,7 +138,7 @@ typedef u16_t tcpflags_t;
#define TCPWND16(x) (x)
#define TCP_WND_MAX(pcb) TCP_WND(pcb)
typedef u16_t tcpwnd_size_t;
typedef u8_t tcpflags_t;
typedef u16_t tcpflags_t;
#endif
enum tcp_state {
@ -203,6 +203,9 @@ struct tcp_pcb {
#define TF_NAGLEMEMERR 0x80U /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
#if LWIP_WND_SCALE
#define TF_WND_SCALE 0x0100U /* Window Scale option enabled */
#endif
#if TCP_LISTEN_BACKLOG
#define TF_BACKLOGPEND 0x0200U /* If this is set, a connection pcb has increased the backlog on its listener */
#endif
/* the rest of the fields are in host byte order
@ -311,6 +314,10 @@ struct tcp_pcb {
u8_t rcv_scale;
#endif
#if TCP_LISTEN_BACKLOG
struct tcp_pcb_listen *listener;
#endif
#if ESP_STATS_TCP
#define ESP_STATS_TCP_ARRAY_SIZE 20
u16_t retry_cnt[TCP_MAXRTX];
@ -383,16 +390,17 @@ void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err);
#define tcp_nagle_disabled(pcb) (((pcb)->flags & TF_NODELAY) != 0)
#if TCP_LISTEN_BACKLOG
#define tcp_accepted(pcb) do { \
LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", pcb->state == LISTEN); \
(((struct tcp_pcb_listen *)(pcb))->accepts_pending--); } while(0)
#define tcp_backlog_set(pcb, new_backlog) do { \
LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", (pcb)->state == LISTEN); \
((struct tcp_pcb_listen *)(pcb))->backlog = ((new_backlog) ? (new_backlog) : 1); } while(0)
void tcp_backlog_delayed(struct tcp_pcb* pcb);
void tcp_backlog_accepted(struct tcp_pcb* pcb);
#else /* TCP_LISTEN_BACKLOG */
#define tcp_accepted(pcb) LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", \
(pcb)->state == LISTEN)
#define tcp_backlog_set(pcb, new_backlog)
#define tcp_backlog_delayed(pcb)
#define tcp_backlog_accepted(pcb)
#endif /* TCP_LISTEN_BACKLOG */
#define tcp_accepted(pcb) do { LWIP_UNUSED_ARG(pcb); } while(0) /* compatibility define, not needed any more */
void tcp_recved (struct tcp_pcb *pcb, u16_t len);
err_t tcp_bind (struct tcp_pcb *pcb, const ip_addr_t *ipaddr,