refactored tcpip_ipv6_output

- brought out several sections of code into seperate helper functions
- reduced conditional nesting by adding new function exit points
- use gotos to eliminate some code duplication (the main goal here
  is to reduce code size so as to avoid compilation problems on some
  platforms).

Conflicts:
	core/net/ip/tcpip.c
This commit is contained in:
Billy Kozak 2016-02-25 09:18:48 -07:00 committed by Simon Duquennoy
parent d4a608cdad
commit 6b40fcc125

View File

@ -108,7 +108,11 @@ enum {
PACKET_INPUT
};
#if UIP_CONF_IPV6_RPL && RPL_WITH_NON_STORING
#define NEXTHOP_NON_STORING(addr) rpl_srh_get_next_hop(addr)
#else
#define NEXTHOP_NON_STORING(addr) 0
#endif
static uint8_t (* outputfunc)(const uip_lladdr_t *a);
@ -450,225 +454,267 @@ tcpip_input(void)
uip_clear_buf();
}
/*---------------------------------------------------------------------------*/
extern void remove_ext_hdr(void);
/*---------------------------------------------------------------------------*/
static void
output_fallback(void)
{
#ifdef UIP_FALLBACK_INTERFACE
PRINTF("FALLBACK: removing ext hdrs & setting proto %d %d\n",
uip_ext_len, *((uint8_t *)UIP_IP_BUF + 40));
if(uip_ext_len > 0) {
uint8_t proto = *((uint8_t *)UIP_IP_BUF + 40);
remove_ext_hdr();
/* This should be copied from the ext header... */
UIP_IP_BUF->proto = proto;
}
/* Inform the other end that the destination is not reachable. If it's
* not informed routes might get lost unexpectedly until there's a need
* to send a new packet to the peer */
if(UIP_FALLBACK_INTERFACE.output() < 0) {
PRINTF("FALLBACK: output error. Reporting DST UNREACH\n");
uip_icmp6_error_output(ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0);
uip_flags = 0;
tcpip_ipv6_output();
return;
}
#else
PRINTF("tcpip_ipv6_output: Destination off-link but no route\n");
#endif /* !UIP_FALLBACK_INTERFACE */
}
/*---------------------------------------------------------------------------*/
static void
drop_route(uip_ds6_route_t *route)
{
#if UIP_CONF_IPV6_RPL
rpl_dag_t *dag;
rpl_instance_t *instance;
/* If we are running RPL, and if we are the root of the
network, we'll trigger a global repair before we remove
the route. */
dag = (rpl_dag_t *)route->state.dag;
if(dag != NULL) {
instance = dag->instance;
rpl_repair_root(instance->instance_id);
}
#endif /* UIP_CONF_IPV6_RPL */
uip_ds6_route_rm(route);
}
/*---------------------------------------------------------------------------*/
static void
annotate_transmission(uip_ipaddr_t *nexthop)
{
#if TCPIP_CONF_ANNOTATE_TRANSMISSIONS
static uint8_t annotate_last;
static uint8_t annotate_has_last = 0;
if(annotate_has_last) {
printf("#L %u 0; red\n", annotate_last);
}
printf("#L %u 1; red\n", nexthop->u8[sizeof(uip_ipaddr_t) - 1]);
annotate_last = nexthop->u8[sizeof(uip_ipaddr_t) - 1];
annotate_has_last = 1;
#endif /* TCPIP_CONF_ANNOTATE_TRANSMISSIONS */
}
/*---------------------------------------------------------------------------*/
static uip_ipaddr_t*
get_nexthop(uip_ipaddr_t *addr)
{
uip_ipaddr_t *nexthop;
uip_ds6_route_t *route;
if(NEXTHOP_NON_STORING(addr)) {
return addr;
}
/* We first check if the destination address is on our immediate
link. If so, we simply use the destination address as our
nexthop address. */
if(uip_ds6_is_addr_onlink(&UIP_IP_BUF->destipaddr)){
return &UIP_IP_BUF->destipaddr;
}
/* Check if we have a route to the destination address. */
route = uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr);
/* No route was found - we send to the default route instead. */
if(route == NULL) {
PRINTF("tcpip_ipv6_output: no route found, using default route\n");
nexthop = uip_ds6_defrt_choose();
if(nexthop == NULL) {
output_fallback();
}
} else {
/* A route was found, so we look up the nexthop neighbor for
the route. */
nexthop = uip_ds6_route_nexthop(route);
/* If the nexthop is dead, for example because the neighbor
never responded to link-layer acks, we drop its route. */
if(nexthop == NULL) {
drop_route(route);
/* We don't have a nexthop to send the packet to, so we drop
it. */
}
}
return nexthop;
}
/*---------------------------------------------------------------------------*/
#if UIP_ND6_SEND_NA
static int
queue_packet(uip_ds6_nbr_t *nbr)
{
/* Copy outgoing pkt in the queuing buffer for later transmit. */
#if UIP_CONF_IPV6_QUEUE_PKT
if(uip_packetqueue_alloc(&nbr->packethandle, UIP_DS6_NBR_PACKET_LIFETIME) != NULL) {
memcpy(uip_packetqueue_buf(&nbr->packethandle), UIP_IP_BUF, uip_len);
uip_packetqueue_set_buflen(&nbr->packethandle, uip_len);
return 0;
}
#endif
return 1;
}
#endif
/*---------------------------------------------------------------------------*/
static void
send_queued(uip_ds6_nbr_t *nbr)
{
#if UIP_CONF_IPV6_QUEUE_PKT
/*
* Send the queued packets from here, may not be 100% perfect though.
* This happens in a few cases, for example when instead of receiving a
* NA after sendiong a NS, you receive a NS with SLLAO: the entry moves
* to STALE, and you must both send a NA and the queued packet.
*/
if(uip_packetqueue_buflen(&nbr->packethandle) != 0) {
uip_len = uip_packetqueue_buflen(&nbr->packethandle);
memcpy(UIP_IP_BUF, uip_packetqueue_buf(&nbr->packethandle), uip_len);
uip_packetqueue_free(&nbr->packethandle);
tcpip_output(uip_ds6_nbr_get_ll(nbr));
}
#endif /*UIP_CONF_IPV6_QUEUE_PKT*/
}
/*---------------------------------------------------------------------------*/
static int
send_nd6_ns(uip_ipaddr_t *nexthop)
{
int err = 1;
#if UIP_ND6_SEND_NA
uip_ds6_nbr_t *nbr = NULL;
if((nbr = uip_ds6_nbr_add(nexthop, NULL, 0, NBR_INCOMPLETE, NBR_TABLE_REASON_IPV6_ND, NULL)) != NULL) {
err = 0;
queue_packet(nbr);
/* RFC4861, 7.2.2:
* "If the source address of the packet prompting the solicitation is the
* same as one of the addresses assigned to the outgoing interface, that
* address SHOULD be placed in the IP Source Address of the outgoing
* solicitation. Otherwise, any one of the addresses assigned to the
* interface should be used."*/
if(uip_ds6_is_my_addr(&UIP_IP_BUF->srcipaddr)){
uip_nd6_ns_output(&UIP_IP_BUF->srcipaddr, NULL, &nbr->ipaddr);
} else {
uip_nd6_ns_output(NULL, NULL, &nbr->ipaddr);
}
stimer_set(&nbr->sendns, uip_ds6_if.retrans_timer / 1000);
nbr->nscount = 1;
/* Send the first NS try from here (multicast destination IP address). */
}
#else
PRINTF("tcpip_ipv6_output: neighbor not in cache\n");
#endif
return err;
}
/*---------------------------------------------------------------------------*/
void
tcpip_ipv6_output(void)
{
uip_ipaddr_t ipaddr;
uip_ds6_nbr_t *nbr = NULL;
uip_ipaddr_t *nexthop = NULL;
const uip_lladdr_t *linkaddr;
uip_ipaddr_t *nexthop;
if(uip_len == 0) {
return;
}
if(uip_len > UIP_LINK_MTU) {
UIP_LOG("tcpip_ipv6_output: Packet to big");
uip_clear_buf();
return;
UIP_LOG("tcpip_ipv6_output: Packet too big");
goto exit;
}
if(uip_is_addr_unspecified(&UIP_IP_BUF->destipaddr)){
UIP_LOG("tcpip_ipv6_output: Destination address unspecified");
uip_clear_buf();
return;
goto exit;
}
#if UIP_CONF_IPV6_RPL
if(!rpl_update_header()) {
/* Packet can not be forwarded */
PRINTF("tcpip_ipv6_output: RPL header update error\n");
uip_clear_buf();
return;
if(uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
linkaddr = NULL;
goto send_packet;
}
#endif /* UIP_CONF_IPV6_RPL */
if(!uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
/* Next hop determination */
if((nexthop = get_nexthop(&ipaddr)) == NULL) {
goto exit;
}
annotate_transmission(nexthop);
#if UIP_CONF_IPV6_RPL && RPL_WITH_NON_STORING
uip_ipaddr_t ipaddr;
/* Look for a RPL Source Route */
if(rpl_srh_get_next_hop(&ipaddr)) {
nexthop = &ipaddr;
}
#endif /* UIP_CONF_IPV6_RPL && RPL_WITH_NON_STORING */
nbr = NULL;
/* We first check if the destination address is on our immediate
link. If so, we simply use the destination address as our
nexthop address. */
if(nexthop == NULL && uip_ds6_is_addr_onlink(&UIP_IP_BUF->destipaddr)){
nexthop = &UIP_IP_BUF->destipaddr;
}
if(nexthop == NULL) {
uip_ds6_route_t *route;
/* Check if we have a route to the destination address. */
route = uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr);
/* No route was found - we send to the default route instead. */
if(route == NULL) {
PRINTF("tcpip_ipv6_output: no route found, using default route\n");
nexthop = uip_ds6_defrt_choose();
if(nexthop == NULL) {
#ifdef UIP_FALLBACK_INTERFACE
PRINTF("FALLBACK: removing ext hdrs & setting proto %d %d\n",
uip_ext_len, *((uint8_t *)UIP_IP_BUF + 40));
if(uip_ext_len > 0) {
extern void remove_ext_hdr(void);
uint8_t proto = *((uint8_t *)UIP_IP_BUF + 40);
remove_ext_hdr();
/* This should be copied from the ext header... */
UIP_IP_BUF->proto = proto;
}
/* Inform the other end that the destination is not reachable. If it's
* not informed routes might get lost unexpectedly until there's a need
* to send a new packet to the peer */
if(UIP_FALLBACK_INTERFACE.output() < 0) {
PRINTF("FALLBACK: output error. Reporting DST UNREACH\n");
uip_icmp6_error_output(ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0);
uip_flags = 0;
tcpip_ipv6_output();
return;
}
#else
PRINTF("tcpip_ipv6_output: Destination off-link but no route\n");
#endif /* !UIP_FALLBACK_INTERFACE */
uip_clear_buf();
return;
}
} else {
/* A route was found, so we look up the nexthop neighbor for
the route. */
nexthop = uip_ds6_route_nexthop(route);
/* If the nexthop is dead, for example because the neighbor
never responded to link-layer acks, we drop its route. */
if(nexthop == NULL) {
#if UIP_CONF_IPV6_RPL
/* If we are running RPL, and if we are the root of the
network, we'll trigger a global repair berfore we remove
the route. */
rpl_dag_t *dag;
rpl_instance_t *instance;
if(!rpl_finalize_header(nexthop)) {
goto exit;
#endif /* UIP_CONF_IPV6_RPL */
}
dag = (rpl_dag_t *)route->state.dag;
if(dag != NULL) {
instance = dag->instance;
rpl_repair_root(instance->instance_id);
}
#endif /* UIP_CONF_IPV6_RPL */
uip_ds6_route_rm(route);
/* We don't have a nexthop to send the packet to, so we drop
it. */
return;
}
}
#if TCPIP_CONF_ANNOTATE_TRANSMISSIONS
if(nexthop != NULL) {
static uint8_t annotate_last;
static uint8_t annotate_has_last = 0;
if(annotate_has_last) {
printf("#L %u 0; red\n", annotate_last);
}
printf("#L %u 1; red\n", nexthop->u8[sizeof(uip_ipaddr_t) - 1]);
annotate_last = nexthop->u8[sizeof(uip_ipaddr_t) - 1];
annotate_has_last = 1;
}
#endif /* TCPIP_CONF_ANNOTATE_TRANSMISSIONS */
}
/* End of next hop determination */
nbr = uip_ds6_nbr_lookup(nexthop);
if(nbr == NULL) {
#if UIP_ND6_SEND_NS
if((nbr = uip_ds6_nbr_add(nexthop, NULL, 0, NBR_INCOMPLETE, NBR_TABLE_REASON_IPV6_ND, NULL)) == NULL) {
uip_clear_buf();
PRINTF("tcpip_ipv6_output: failed to add neighbor to cache\n");
return;
} else {
#if UIP_CONF_IPV6_QUEUE_PKT
/* Copy outgoing pkt in the queuing buffer for later transmit. */
if(uip_packetqueue_alloc(&nbr->packethandle, UIP_DS6_NBR_PACKET_LIFETIME) != NULL) {
memcpy(uip_packetqueue_buf(&nbr->packethandle), UIP_IP_BUF, uip_len);
uip_packetqueue_set_buflen(&nbr->packethandle, uip_len);
}
#endif
/* RFC4861, 7.2.2:
* "If the source address of the packet prompting the solicitation is the
* same as one of the addresses assigned to the outgoing interface, that
* address SHOULD be placed in the IP Source Address of the outgoing
* solicitation. Otherwise, any one of the addresses assigned to the
* interface should be used."*/
if(uip_ds6_is_my_addr(&UIP_IP_BUF->srcipaddr)){
uip_nd6_ns_output(&UIP_IP_BUF->srcipaddr, NULL, &nbr->ipaddr);
} else {
uip_nd6_ns_output(NULL, NULL, &nbr->ipaddr);
}
stimer_set(&nbr->sendns, uip_ds6_if.retrans_timer / 1000);
nbr->nscount = 1;
/* Send the first NS try from here (multicast destination IP address). */
}
#else /* UIP_ND6_SEND_NS */
PRINTF("tcpip_ipv6_output: neighbor not in cache\n");
uip_len = 0;
return;
#endif /* UIP_ND6_SEND_NS */
nbr = uip_ds6_nbr_lookup(nexthop);
if(nbr == NULL) {
if(send_nd6_ns(nexthop)) {
PRINTF("tcpip_ipv6_output: failed to add neighbor to cache\n");
goto exit;
} else {
#if UIP_ND6_SEND_NS
if(nbr->state == NBR_INCOMPLETE) {
PRINTF("tcpip_ipv6_output: nbr cache entry incomplete\n");
#if UIP_CONF_IPV6_QUEUE_PKT
/* Copy outgoing pkt in the queuing buffer for later transmit and set
the destination nbr to nbr. */
if(uip_packetqueue_alloc(&nbr->packethandle, UIP_DS6_NBR_PACKET_LIFETIME) != NULL) {
memcpy(uip_packetqueue_buf(&nbr->packethandle), UIP_IP_BUF, uip_len);
uip_packetqueue_set_buflen(&nbr->packethandle, uip_len);
}
#endif /*UIP_CONF_IPV6_QUEUE_PKT*/
uip_clear_buf();
return;
}
/* Send in parallel if we are running NUD (nbc state is either STALE,
DELAY, or PROBE). See RFC 4861, section 7.3.3 on node behavior. */
if(nbr->state == NBR_STALE) {
nbr->state = NBR_DELAY;
stimer_set(&nbr->reachable, UIP_ND6_DELAY_FIRST_PROBE_TIME);
nbr->nscount = 0;
PRINTF("tcpip_ipv6_output: nbr cache entry stale moving to delay\n");
}
#endif /* UIP_ND6_SEND_NS */
tcpip_output(uip_ds6_nbr_get_ll(nbr));
#if UIP_CONF_IPV6_QUEUE_PKT
/*
* Send the queued packets from here, may not be 100% perfect though.
* This happens in a few cases, for example when instead of receiving a
* NA after sendiong a NS, you receive a NS with SLLAO: the entry moves
* to STALE, and you must both send a NA and the queued packet.
*/
if(uip_packetqueue_buflen(&nbr->packethandle) != 0) {
uip_len = uip_packetqueue_buflen(&nbr->packethandle);
memcpy(UIP_IP_BUF, uip_packetqueue_buf(&nbr->packethandle), uip_len);
uip_packetqueue_free(&nbr->packethandle);
tcpip_output(uip_ds6_nbr_get_ll(nbr));
}
#endif /*UIP_CONF_IPV6_QUEUE_PKT*/
uip_clear_buf();
return;
goto send_packet;
}
}
/* Multicast IP destination address. */
tcpip_output(NULL);
#if UIP_ND6_SEND_NA
if(nbr->state == NBR_INCOMPLETE) {
PRINTF("tcpip_ipv6_output: nbr cache entry incomplete\n");
queue_packet(nbr);
goto exit;
}
/* Send in parallel if we are running NUD (nbc state is either STALE,
DELAY, or PROBE). See RFC 4861, section 7.3.3 on node behavior. */
if(nbr->state == NBR_STALE) {
nbr->state = NBR_DELAY;
stimer_set(&nbr->reachable, UIP_ND6_DELAY_FIRST_PROBE_TIME);
nbr->nscount = 0;
PRINTF("tcpip_ipv6_output: nbr cache entry stale moving to delay\n");
}
#endif /* UIP_ND6_SEND_NA */
send_packet:
if(nbr) {
linkaddr = uip_ds6_nbr_get_ll(nbr);
} else {
linkaddr = NULL;
}
tcpip_output(linkaddr);
if(nbr) {
send_queued(nbr);
}
exit:
uip_clear_buf();
return;
}
/*---------------------------------------------------------------------------*/
#if UIP_UDP