Major bugfix, found by Raimondas Sasnauskas: the TCP periodic timer was not started when a new connection request arrived. If there were no other active TCP connections, this means that the SYNACK would never be retransmitted, potentially leading to a forever stale TCP connection.

This commit is contained in:
adamdunkels 2010-02-09 12:58:53 +00:00
parent a6c6522548
commit d67d1f7340

View File

@ -29,7 +29,7 @@
* This file is part of the Contiki operating system. * This file is part of the Contiki operating system.
* *
* *
* $Id: tcpip.c,v 1.23 2010/02/05 12:43:36 nifi Exp $ * $Id: tcpip.c,v 1.24 2010/02/09 12:58:53 adamdunkels Exp $
*/ */
/** /**
* \file * \file
@ -71,6 +71,7 @@ void uip_log(char *msg);
#define UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[UIP_LLIPH_LEN + uip_ext_len]) #define UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[UIP_LLIPH_LEN + uip_ext_len])
#define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN]) #define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
#define UIP_TCP_BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
process_event_t tcpip_event; process_event_t tcpip_event;
#if UIP_CONF_ICMP6 #if UIP_CONF_ICMP6
@ -156,6 +157,29 @@ unsigned char tcpip_is_forwarding; /* Forwarding right now? */
PROCESS(tcpip_process, "TCP/IP stack"); PROCESS(tcpip_process, "TCP/IP stack");
/*---------------------------------------------------------------------------*/
static void
start_periodic_tcp_timer(void)
{
if(etimer_expired(&periodic)) {
etimer_restart(&periodic);
}
}
/*---------------------------------------------------------------------------*/
static void
check_for_tcp_syn(void)
{
/* This is a hack that is needed to start the periodic TCP timer if
an incoming packet contains a SYN: since uIP does not inform the
application if a SYN arrives, we have no other way of starting
this timer. This function is called for every incoming IP packet
to check for such SYNs. */
#define TCP_SYN 0x02
if(UIP_IP_BUF->proto == UIP_PROTO_TCP &&
(UIP_TCP_BUF->flags & TCP_SYN) == TCP_SYN) {
start_periodic_tcp_timer();
}
}
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
static void static void
packet_input(void) packet_input(void)
@ -165,6 +189,7 @@ packet_input(void)
tcpip_is_forwarding = 1; tcpip_is_forwarding = 1;
if(uip_fw_forward() == UIP_FW_LOCAL) { if(uip_fw_forward() == UIP_FW_LOCAL) {
tcpip_is_forwarding = 0; tcpip_is_forwarding = 0;
check_for_tcp_syn();
uip_input(); uip_input();
if(uip_len > 0) { if(uip_len > 0) {
#if UIP_CONF_TCP_SPLIT #if UIP_CONF_TCP_SPLIT
@ -183,6 +208,7 @@ packet_input(void)
} }
#else /* UIP_CONF_IP_FORWARD */ #else /* UIP_CONF_IP_FORWARD */
if(uip_len > 0) { if(uip_len > 0) {
check_for_tcp_syn();
uip_input(); uip_input();
if(uip_len > 0) { if(uip_len > 0) {
#if UIP_CONF_TCP_SPLIT #if UIP_CONF_TCP_SPLIT
@ -199,12 +225,8 @@ packet_input(void)
} }
#endif /* UIP_CONF_IP_FORWARD */ #endif /* UIP_CONF_IP_FORWARD */
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
#if UIP_TCP #if UIP_TCP
#if UIP_ACTIVE_OPEN #if UIP_ACTIVE_OPEN
struct uip_conn * struct uip_conn *
tcp_connect(uip_ipaddr_t *ripaddr, u16_t port, void *appstate) tcp_connect(uip_ipaddr_t *ripaddr, u16_t port, void *appstate)
@ -273,10 +295,7 @@ tcp_attach(struct uip_conn *conn,
} }
#endif /* UIP_TCP */ #endif /* UIP_TCP */
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
#if UIP_UDP #if UIP_UDP
void void
udp_attach(struct uip_udp_conn *conn, udp_attach(struct uip_udp_conn *conn,
@ -349,7 +368,6 @@ tcpip_icmp6_call(u8_t type)
} }
#endif /* UIP_CONF_ICMP6 */ #endif /* UIP_CONF_ICMP6 */
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
static void static void
eventhandler(process_event_t ev, process_data_t data) eventhandler(process_event_t ev, process_data_t data)
{ {
@ -483,17 +501,14 @@ eventhandler(process_event_t ev, process_data_t data)
uip_poll_conn(data); uip_poll_conn(data);
#if UIP_CONF_IPV6 #if UIP_CONF_IPV6
tcpip_ipv6_output(); tcpip_ipv6_output();
#else #else /* UIP_CONF_IPV6 */
if(uip_len > 0) { if(uip_len > 0) {
PRINTF("tcpip_output from tcp poll len %d\n", uip_len); PRINTF("tcpip_output from tcp poll len %d\n", uip_len);
tcpip_output(); tcpip_output();
} }
#endif /* UIP_CONF_IPV6 */ #endif /* UIP_CONF_IPV6 */
/* Start the periodic polling, if it isn't already active. */ /* Start the periodic polling, if it isn't already active. */
if(etimer_expired(&periodic)) { start_periodic_tcp_timer();
etimer_restart(&periodic);
}
} }
break; break;
#endif /* UIP_TCP */ #endif /* UIP_TCP */
@ -720,12 +735,10 @@ tcpip_uipcall(void)
} }
/* Start the periodic polling, if it isn't already active. */ /* Start the periodic polling, if it isn't already active. */
if(etimer_expired(&periodic)) { start_periodic_tcp_timer();
etimer_restart(&periodic);
} }
} }
} #endif /* UIP_TCP */
#endif
if(ts->p != NULL) { if(ts->p != NULL) {
process_post_synch(ts->p, tcpip_event, ts->state); process_post_synch(ts->p, tcpip_event, ts->state);
@ -751,7 +764,7 @@ PROCESS_THREAD(tcpip_process, ev, data)
#if UIP_CONF_ICMP6 #if UIP_CONF_ICMP6
tcpip_icmp6_event = process_alloc_event(); tcpip_icmp6_event = process_alloc_event();
#endif /* UIP_CONF_ICMP6 */ #endif /* UIP_CONF_ICMP6 */
etimer_set(&periodic, CLOCK_SECOND/2); etimer_set(&periodic, CLOCK_SECOND / 2);
uip_init(); uip_init();