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fixed bug #31177: tcp timers can corrupt tcp_active_pcbs in some cases

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This commit is contained in:
goldsimon 2011-11-25 18:36:52 +01:00
parent 4c8e4fa003
commit 56207f2505
5 changed files with 85 additions and 24 deletions
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4
CHANGELOG
View File

@ -49,6 +49,10 @@ HISTORY
++ Bugfixes:
2011-11-25: Simon Goldschmidt
* tcp.h/.c, tcp_impl.h, tcp_in.c: fixed bug #31177: tcp timers can corrupt
tcp_active_pcbs in some cases
2011-11-23: Simon Goldschmidt
* sys.c: fixed bug #34884: sys_msleep() body needs to be surrounded with
'#ifndef sys_msleep'

77
src/core/tcp.c
View File

@ -116,8 +116,11 @@ struct tcp_pcb ** const tcp_pcb_lists[] = {&tcp_listen_pcbs.pcbs, &tcp_bound_pcb
/** Only used for temporary storage. */
struct tcp_pcb *tcp_tmp_pcb;
u8_t tcp_active_pcbs_changed;
/** Timer counter to handle calling slow-timer from tcp_tmr() */
static u8_t tcp_timer;
static u8_t tcp_timer_ctr;
static u16_t tcp_new_port(void);
/**
@ -184,7 +187,7 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
/* TODO: to which state do we move now? */
/* move to TIME_WAIT since we close actively */
TCP_RMV(&tcp_active_pcbs, pcb);
TCP_RMV_ACTIVE(pcb);
pcb->state = TIME_WAIT;
TCP_REG(&tcp_tw_pcbs, pcb);
@ -216,7 +219,7 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
break;
case SYN_SENT:
err = ERR_OK;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
TCP_PCB_REMOVE_ACTIVE(pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
snmp_inc_tcpattemptfails();
@ -374,7 +377,7 @@ tcp_abandon(struct tcp_pcb *pcb, int reset)
errf = pcb->errf;
#endif /* LWIP_CALLBACK_API */
errf_arg = pcb->callback_arg;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
TCP_PCB_REMOVE_ACTIVE(pcb);
if (pcb->unacked != NULL) {
tcp_segs_free(pcb->unacked);
}
@ -765,7 +768,7 @@ tcp_connect(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port,
if (old_local_port != 0) {
TCP_RMV(&tcp_bound_pcbs, pcb);
}
TCP_REG(&tcp_active_pcbs, pcb);
TCP_REG_ACTIVE(pcb);
snmp_inc_tcpactiveopens();
tcp_output(pcb);
@ -792,7 +795,9 @@ tcp_slowtmr(void)
err = ERR_OK;
++tcp_ticks;
++tcp_timer_ctr;
tcp_slowtmr_start:
/* Steps through all of the active PCBs. */
prev = NULL;
pcb = tcp_active_pcbs;
@ -804,6 +809,12 @@ tcp_slowtmr(void)
LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
if (pcb->last_timer == tcp_timer_ctr) {
/* skip this pcb, we have already processed it */
pcb = pcb->next;
continue;
}
pcb->last_timer = tcp_timer_ctr;
pcb_remove = 0;
pcb_reset = 0;
@ -929,6 +940,8 @@ tcp_slowtmr(void)
/* If the PCB should be removed, do it. */
if (pcb_remove) {
struct tcp_pcb *pcb2;
tcp_err_fn err_fn;
void *err_arg;
tcp_pcb_purge(pcb);
/* Remove PCB from tcp_active_pcbs list. */
if (prev != NULL) {
@ -940,15 +953,22 @@ tcp_slowtmr(void)
tcp_active_pcbs = pcb->next;
}
TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
if (pcb_reset) {
tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
pcb->local_port, pcb->remote_port);
}
err_fn = pcb->errf;
err_arg = pcb->callback_arg;
pcb2 = pcb;
pcb = pcb->next;
memp_free(MEMP_TCP_PCB, pcb2);
tcp_active_pcbs_changed = 0;
TCP_EVENT_ERR(err_fn, err_arg, ERR_ABRT);
if (tcp_active_pcbs_changed) {
goto tcp_slowtmr_start;
}
} else {
/* get the 'next' element now and work with 'prev' below (in case of abort) */
prev = pcb;
@ -959,7 +979,11 @@ tcp_slowtmr(void)
if (prev->polltmr >= prev->pollinterval) {
prev->polltmr = 0;
LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
tcp_active_pcbs_changed = 0;
TCP_EVENT_POLL(prev, err);
if (tcp_active_pcbs_changed) {
goto tcp_slowtmr_start;
}
/* if err == ERR_ABRT, 'prev' is already deallocated */
if (err == ERR_OK) {
tcp_output(prev);
@ -1015,26 +1039,38 @@ tcp_slowtmr(void)
void
tcp_fasttmr(void)
{
struct tcp_pcb *pcb = tcp_active_pcbs;
struct tcp_pcb *pcb;
++tcp_timer_ctr;
tcp_fasttmr_start:
pcb = tcp_active_pcbs;
while(pcb != NULL) {
struct tcp_pcb *next = pcb->next;
/* If there is data which was previously "refused" by upper layer */
if (pcb->refused_data != NULL) {
if (tcp_process_refused_data(pcb) == ERR_ABRT) {
pcb = NULL;
if (pcb->last_timer != tcp_timer_ctr) {
struct tcp_pcb *next;
pcb->last_timer = tcp_timer_ctr;
/* send delayed ACKs */
if (pcb->flags & TF_ACK_DELAY) {
LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
tcp_ack_now(pcb);
tcp_output(pcb);
pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
}
}
/* send delayed ACKs */
if (pcb && (pcb->flags & TF_ACK_DELAY)) {
LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
tcp_ack_now(pcb);
tcp_output(pcb);
pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
}
next = pcb->next;
pcb = next;
/* If there is data which was previously "refused" by upper layer */
if (pcb->refused_data != NULL) {
tcp_active_pcbs_changed = 0;
tcp_process_refused_data(pcb);
if (tcp_active_pcbs_changed) {
/* application callback has changed the pcb list: restart the loop */
goto tcp_fasttmr_start;
}
}
pcb = next;
}
}
}
@ -1284,6 +1320,7 @@ tcp_alloc(u8_t prio)
pcb->lastack = iss;
pcb->snd_lbb = iss;
pcb->tmr = tcp_ticks;
pcb->last_timer = tcp_timer_ctr;
pcb->polltmr = 0;

8
src/core/tcp_in.c
View File

@ -487,7 +487,7 @@ tcp_listen_input(struct tcp_pcb_listen *pcb)
npcb->so_options = pcb->so_options & SOF_INHERITED;
/* Register the new PCB so that we can begin receiving segments
for it. */
TCP_REG(&tcp_active_pcbs, npcb);
TCP_REG_ACTIVE(npcb);
/* Parse any options in the SYN. */
tcp_parseopt(npcb);
@ -735,7 +735,7 @@ tcp_process(struct tcp_pcb *pcb)
("TCP connection closed: FIN_WAIT_1 %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
tcp_ack_now(pcb);
tcp_pcb_purge(pcb);
TCP_RMV(&tcp_active_pcbs, pcb);
TCP_RMV_ACTIVE(pcb);
pcb->state = TIME_WAIT;
TCP_REG(&tcp_tw_pcbs, pcb);
} else {
@ -752,7 +752,7 @@ tcp_process(struct tcp_pcb *pcb)
LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: FIN_WAIT_2 %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
tcp_ack_now(pcb);
tcp_pcb_purge(pcb);
TCP_RMV(&tcp_active_pcbs, pcb);
TCP_RMV_ACTIVE(pcb);
pcb->state = TIME_WAIT;
TCP_REG(&tcp_tw_pcbs, pcb);
}
@ -762,7 +762,7 @@ tcp_process(struct tcp_pcb *pcb)
if (flags & TCP_ACK && ackno == pcb->snd_nxt) {
LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: CLOSING %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
tcp_pcb_purge(pcb);
TCP_RMV(&tcp_active_pcbs, pcb);
TCP_RMV_ACTIVE(pcb);
pcb->state = TIME_WAIT;
TCP_REG(&tcp_tw_pcbs, pcb);
}

1
src/include/lwip/tcp.h
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@ -189,6 +189,7 @@ struct tcp_pcb {
/* Timers */
u8_t polltmr, pollinterval;
u8_t last_timer;
u32_t tmr;
/* receiver variables */

19
src/include/lwip/tcp_impl.h
View File

@ -307,6 +307,7 @@ struct tcp_seg {
/* Global variables: */
extern struct tcp_pcb *tcp_input_pcb;
extern u32_t tcp_ticks;
extern u8_t tcp_active_pcbs_changed;
/* The TCP PCB lists. */
union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */
@ -393,6 +394,24 @@ extern struct tcp_pcb *tcp_tmp_pcb; /* Only used for temporary storage. */
#endif /* LWIP_DEBUG */
#define TCP_REG_ACTIVE(npcb) \
do { \
TCP_REG(&tcp_active_pcbs, npcb); \
tcp_active_pcbs_changed = 1; \
} while (0)
#define TCP_RMV_ACTIVE(npcb) \
do { \
TCP_RMV(&tcp_active_pcbs, npcb); \
tcp_active_pcbs_changed = 1; \
} while (0)
#define TCP_PCB_REMOVE_ACTIVE(pcb) \
do { \
tcp_pcb_remove(&tcp_active_pcbs, pcb); \
tcp_active_pcbs_changed = 1; \
} while (0)
/* Internal functions: */
struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);