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8968b7602f
RIOT/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
Martine Lenders 8968b7602f gnrc_ndp: don't let addresses timeout 
This is a temporary quick-fix for #5122 to not have GUAs removed on an
interface.
It solves the issue by both not letting the registration run out on the router
and by not letting the lifetime of an auto-configured address expire.
2016-04-20 13:31:53 +02:00

954 lines
31 KiB
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/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @{
*
* @file
*/
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <stdbool.h>
#include "byteorder.h"
#include "cpu_conf.h"
#include "kernel_types.h"
#include "net/gnrc.h"
#include "net/gnrc/icmpv6.h"
#include "net/gnrc/ndp.h"
#include "net/gnrc/sixlowpan/ctx.h"
#include "net/gnrc/sixlowpan/nd.h"
#include "net/gnrc/sixlowpan/nd/router.h"
#include "net/protnum.h"
#include "thread.h"
#include "utlist.h"
#include "net/gnrc/ipv6/nc.h"
#include "net/gnrc/ipv6/netif.h"
#include "net/gnrc/ipv6/whitelist.h"
#include "net/gnrc/ipv6/blacklist.h"
#include "net/gnrc/ipv6.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
#define _MAX_L2_ADDR_LEN (8U)
#if ENABLE_DEBUG
static char _stack[GNRC_IPV6_STACK_SIZE + THREAD_EXTRA_STACKSIZE_PRINTF];
#else
static char _stack[GNRC_IPV6_STACK_SIZE];
#endif
#ifdef MODULE_FIB
#include "net/fib.h"
#include "net/fib/table.h"
/**
* @brief buffer to store the entries in the IPv6 forwarding table
*/
static fib_entry_t _fib_entries[GNRC_IPV6_FIB_TABLE_SIZE];
/**
* @brief the IPv6 forwarding table
*/
fib_table_t gnrc_ipv6_fib_table;
#endif
#if ENABLE_DEBUG
static char addr_str[IPV6_ADDR_MAX_STR_LEN];
#endif
kernel_pid_t gnrc_ipv6_pid = KERNEL_PID_UNDEF;
/* handles GNRC_NETAPI_MSG_TYPE_RCV commands */
static void _receive(gnrc_pktsnip_t *pkt);
/* dispatches received IPv6 packet for upper layer */
static void _dispatch_rcv_pkt(gnrc_nettype_t type, uint32_t demux_ctx,
gnrc_pktsnip_t *pkt);
/* Sends packet over the appropriate interface(s).
* prep_hdr: prepare header for sending (call to _fill_ipv6_hdr()), otherwise
* assume it is already prepared */
static void _send(gnrc_pktsnip_t *pkt, bool prep_hdr);
/* Main event loop for IPv6 */
static void *_event_loop(void *args);
/* Handles encapsulated IPv6 packets: http://tools.ietf.org/html/rfc2473 */
static void _decapsulate(gnrc_pktsnip_t *pkt);
kernel_pid_t gnrc_ipv6_init(void)
{
if (gnrc_ipv6_pid == KERNEL_PID_UNDEF) {
gnrc_ipv6_pid = thread_create(_stack, sizeof(_stack), GNRC_IPV6_PRIO,
THREAD_CREATE_STACKTEST,
_event_loop, NULL, "ipv6");
}
#ifdef MODULE_FIB
gnrc_ipv6_fib_table.data.entries = _fib_entries;
gnrc_ipv6_fib_table.table_type = FIB_TABLE_TYPE_SH;
gnrc_ipv6_fib_table.size = GNRC_IPV6_FIB_TABLE_SIZE;
fib_init(&gnrc_ipv6_fib_table);
#endif
return gnrc_ipv6_pid;
}
/*
* current pkt
* | |
* v v
* IPv6 <- IPv6_EXT <- IPv6_EXT <- UNDEF
*/
void gnrc_ipv6_demux(kernel_pid_t iface, gnrc_pktsnip_t *current, gnrc_pktsnip_t *pkt, uint8_t nh)
{
int receiver_num;
bool interested = false;
pkt->type = gnrc_nettype_from_protnum(nh);
switch (nh) {
#ifdef MODULE_GNRC_ICMPV6
case PROTNUM_ICMPV6:
assert(current == pkt);
interested = true;
break;
#endif
#ifdef MODULE_GNRC_IPV6_EXT
case PROTNUM_IPV6_EXT_HOPOPT:
case PROTNUM_IPV6_EXT_DST:
case PROTNUM_IPV6_EXT_RH:
case PROTNUM_IPV6_EXT_FRAG:
case PROTNUM_IPV6_EXT_AH:
case PROTNUM_IPV6_EXT_ESP:
case PROTNUM_IPV6_EXT_MOB:
interested = true;
break;
#endif
case PROTNUM_IPV6:
assert(current == pkt);
interested = true;
break;
default:
(void)iface;
break;
}
DEBUG("ipv6: forward nh = %u to other threads\n", nh);
receiver_num = gnrc_netreg_num(pkt->type, GNRC_NETREG_DEMUX_CTX_ALL) +
gnrc_netreg_num(GNRC_NETTYPE_IPV6, nh);
if (receiver_num == 0) {
DEBUG("ipv6: unable to forward packet as no one is interested in it\n");
if (!interested) {
assert(current == pkt);
gnrc_pktbuf_release(pkt);
return;
}
}
else {
if (!interested) {
assert(current == pkt);
/* IPv6 is not interested anymore so `- 1` */
receiver_num--;
}
gnrc_pktbuf_hold(current, receiver_num);
/* XXX can't use gnrc_netapi_dispatch_receive() twice here since a call to that function
* implicitly hands all rights to the packet to one of the receiving threads. As a
* result, the second call to gnrc_netapi_dispatch_receive() would be invalid */
_dispatch_rcv_pkt(current->type, GNRC_NETREG_DEMUX_CTX_ALL, current);
_dispatch_rcv_pkt(GNRC_NETTYPE_IPV6, nh, current);
if (!interested) {
return;
}
}
switch (nh) {
#ifdef MODULE_GNRC_ICMPV6
case PROTNUM_ICMPV6:
DEBUG("ipv6: handle ICMPv6 packet (nh = %u)\n", nh);
gnrc_icmpv6_demux(iface, pkt);
break;
#endif
#ifdef MODULE_GNRC_IPV6_EXT
case PROTNUM_IPV6_EXT_HOPOPT:
case PROTNUM_IPV6_EXT_DST:
case PROTNUM_IPV6_EXT_RH:
case PROTNUM_IPV6_EXT_FRAG:
case PROTNUM_IPV6_EXT_AH:
case PROTNUM_IPV6_EXT_ESP:
case PROTNUM_IPV6_EXT_MOB:
DEBUG("ipv6: handle extension header (nh = %u)\n", nh);
gnrc_ipv6_ext_demux(iface, current, pkt, nh);
return;
#endif
case PROTNUM_IPV6:
DEBUG("ipv6: handle encapsulated IPv6 packet (nh = %u)\n", nh);
_decapsulate(pkt);
return;
default:
break;
}
assert(current == pkt);
gnrc_pktbuf_release(pkt);
}
/* internal functions */
static void *_event_loop(void *args)
{
msg_t msg, reply, msg_q[GNRC_IPV6_MSG_QUEUE_SIZE];
gnrc_netreg_entry_t me_reg;
(void)args;
msg_init_queue(msg_q, GNRC_IPV6_MSG_QUEUE_SIZE);
me_reg.demux_ctx = GNRC_NETREG_DEMUX_CTX_ALL;
me_reg.pid = thread_getpid();
/* register interest in all IPv6 packets */
gnrc_netreg_register(GNRC_NETTYPE_IPV6, &me_reg);
/* preinitialize ACK */
reply.type = GNRC_NETAPI_MSG_TYPE_ACK;
/* start event loop */
while (1) {
DEBUG("ipv6: waiting for incoming message.\n");
msg_receive(&msg);
switch (msg.type) {
case GNRC_NETAPI_MSG_TYPE_RCV:
DEBUG("ipv6: GNRC_NETAPI_MSG_TYPE_RCV received\n");
_receive((gnrc_pktsnip_t *)msg.content.ptr);
break;
case GNRC_NETAPI_MSG_TYPE_SND:
DEBUG("ipv6: GNRC_NETAPI_MSG_TYPE_SND received\n");
_send((gnrc_pktsnip_t *)msg.content.ptr, true);
break;
case GNRC_NETAPI_MSG_TYPE_GET:
case GNRC_NETAPI_MSG_TYPE_SET:
DEBUG("ipv6: reply to unsupported get/set\n");
reply.content.value = -ENOTSUP;
msg_reply(&msg, &reply);
break;
#ifdef MODULE_GNRC_NDP
case GNRC_NDP_MSG_RTR_TIMEOUT:
DEBUG("ipv6: Router timeout received\n");
((gnrc_ipv6_nc_t *)msg.content.ptr)->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
break;
/* XXX reactivate when https://github.com/RIOT-OS/RIOT/issues/5122 is
* solved properly */
/* case GNRC_NDP_MSG_ADDR_TIMEOUT: */
/* DEBUG("ipv6: Router advertisement timer event received\n"); */
/* gnrc_ipv6_netif_remove_addr(KERNEL_PID_UNDEF, */
/* (ipv6_addr_t *)msg.content.ptr); */
/* break; */
case GNRC_NDP_MSG_NBR_SOL_RETRANS:
DEBUG("ipv6: Neigbor solicitation retransmission timer event received\n");
gnrc_ndp_retrans_nbr_sol((gnrc_ipv6_nc_t *)msg.content.ptr);
break;
case GNRC_NDP_MSG_NC_STATE_TIMEOUT:
DEBUG("ipv6: Neigbor cache state timeout received\n");
gnrc_ndp_state_timeout((gnrc_ipv6_nc_t *)msg.content.ptr);
break;
#endif
#ifdef MODULE_GNRC_NDP_ROUTER
case GNRC_NDP_MSG_RTR_ADV_RETRANS:
DEBUG("ipv6: Router advertisement retransmission event received\n");
gnrc_ndp_router_retrans_rtr_adv((gnrc_ipv6_netif_t *)msg.content.ptr);
break;
case GNRC_NDP_MSG_RTR_ADV_DELAY:
DEBUG("ipv6: Delayed router advertisement event received\n");
gnrc_ndp_router_send_rtr_adv((gnrc_ipv6_nc_t *)msg.content.ptr);
break;
#endif
#ifdef MODULE_GNRC_NDP_HOST
case GNRC_NDP_MSG_RTR_SOL_RETRANS:
DEBUG("ipv6: Router solicitation retransmission event received\n");
gnrc_ndp_host_retrans_rtr_sol((gnrc_ipv6_netif_t *)msg.content.ptr);
break;
#endif
#ifdef MODULE_GNRC_SIXLOWPAN_ND
case GNRC_SIXLOWPAN_ND_MSG_MC_RTR_SOL:
DEBUG("ipv6: Multicast router solicitation event received\n");
gnrc_sixlowpan_nd_mc_rtr_sol((gnrc_ipv6_netif_t *)msg.content.ptr);
break;
case GNRC_SIXLOWPAN_ND_MSG_UC_RTR_SOL:
DEBUG("ipv6: Unicast router solicitation event received\n");
gnrc_sixlowpan_nd_uc_rtr_sol((gnrc_ipv6_nc_t *)msg.content.ptr);
break;
# ifdef MODULE_GNRC_SIXLOWPAN_CTX
case GNRC_SIXLOWPAN_ND_MSG_DELETE_CTX:
DEBUG("ipv6: Delete 6LoWPAN context event received\n");
gnrc_sixlowpan_ctx_remove(((((gnrc_sixlowpan_ctx_t *)msg.content.ptr)->flags_id) &
GNRC_SIXLOWPAN_CTX_FLAGS_CID_MASK));
break;
# endif
#endif
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
case GNRC_SIXLOWPAN_ND_MSG_ABR_TIMEOUT:
DEBUG("ipv6: border router timeout event received\n");
gnrc_sixlowpan_nd_router_abr_remove(
(gnrc_sixlowpan_nd_router_abr_t *)msg.content.ptr);
break;
/* XXX reactivate when https://github.com/RIOT-OS/RIOT/issues/5122 is
* solved properly */
/* case GNRC_SIXLOWPAN_ND_MSG_AR_TIMEOUT: */
/* DEBUG("ipv6: address registration timeout received\n"); */
/* gnrc_sixlowpan_nd_router_gc_nc((gnrc_ipv6_nc_t *)msg.content.ptr); */
/* break; */
case GNRC_NDP_MSG_RTR_ADV_SIXLOWPAN_DELAY:
DEBUG("ipv6: Delayed router advertisement event received\n");
gnrc_ipv6_nc_t *nc_entry = (gnrc_ipv6_nc_t *)msg.content.ptr;
gnrc_ndp_internal_send_rtr_adv(nc_entry->iface, NULL,
&(nc_entry->ipv6_addr), false);
break;
#endif
default:
break;
}
}
return NULL;
}
static void _send_to_iface(kernel_pid_t iface, gnrc_pktsnip_t *pkt)
{
((gnrc_netif_hdr_t *)pkt->data)->if_pid = iface;
gnrc_ipv6_netif_t *if_entry = gnrc_ipv6_netif_get(iface);
assert(if_entry != NULL);
if (gnrc_pkt_len(pkt->next) > if_entry->mtu) {
DEBUG("ipv6: packet too big\n");
gnrc_pktbuf_release(pkt);
return;
}
#ifdef MODULE_GNRC_SIXLOWPAN
if ((if_entry != NULL) && (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN)) {
DEBUG("ipv6: send to 6LoWPAN instead\n");
if (!gnrc_netapi_dispatch_send(GNRC_NETTYPE_SIXLOWPAN, GNRC_NETREG_DEMUX_CTX_ALL, pkt)) {
DEBUG("ipv6: no 6LoWPAN thread found");
gnrc_pktbuf_release(pkt);
}
return;
}
#endif
if (gnrc_netapi_send(iface, pkt) < 1) {
DEBUG("ipv6: unable to send packet\n");
gnrc_pktbuf_release(pkt);
}
}
/* functions for sending */
static void _send_unicast(kernel_pid_t iface, uint8_t *dst_l2addr,
uint16_t dst_l2addr_len, gnrc_pktsnip_t *pkt)
{
gnrc_pktsnip_t *netif;
if (pkt->type == GNRC_NETTYPE_NETIF) {
/* great: someone already added a netif_hdr_t we assume it's wrong
* to keep it simple
* XXX: alternative would be to check if gnrc_netif_hdr_t::dst_l2addr_len
* is long enough and only then to throw away the header. This causes
* to much overhead IMHO */
DEBUG("ipv6: removed old interface header\n");
pkt = gnrc_pktbuf_remove_snip(pkt, pkt);
}
DEBUG("ipv6: add interface header to packet\n");
netif = gnrc_netif_hdr_build(NULL, 0, dst_l2addr, dst_l2addr_len);
if (netif == NULL) {
DEBUG("ipv6: error on interface header allocation, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
/* add netif to front of the pkt list */
LL_PREPEND(pkt, netif);
DEBUG("ipv6: send unicast over interface %" PRIkernel_pid "\n", iface);
/* and send to interface */
_send_to_iface(iface, pkt);
}
static int _fill_ipv6_hdr(kernel_pid_t iface, gnrc_pktsnip_t *ipv6,
gnrc_pktsnip_t *payload)
{
int res;
ipv6_hdr_t *hdr = ipv6->data;
hdr->len = byteorder_htons(gnrc_pkt_len(payload));
DEBUG("ipv6: set payload length to %u (network byteorder %04" PRIx16 ")\n",
(unsigned) gnrc_pkt_len(payload), hdr->len.u16);
/* check if e.g. extension header was not already marked */
if (hdr->nh == PROTNUM_RESERVED) {
hdr->nh = gnrc_nettype_to_protnum(payload->type);
/* if still reserved: mark no next header */
if (hdr->nh == PROTNUM_RESERVED) {
hdr->nh = PROTNUM_IPV6_NONXT;
}
}
DEBUG("ipv6: set next header to %u\n", hdr->nh);
if (hdr->hl == 0) {
if (iface == KERNEL_PID_UNDEF) {
hdr->hl = GNRC_IPV6_NETIF_DEFAULT_HL;
}
else {
hdr->hl = gnrc_ipv6_netif_get(iface)->cur_hl;
}
}
if (ipv6_addr_is_unspecified(&hdr->src)) {
if (ipv6_addr_is_loopback(&hdr->dst)) {
ipv6_addr_set_loopback(&hdr->src);
}
else {
ipv6_addr_t *src = gnrc_ipv6_netif_find_best_src_addr(iface, &hdr->dst, false);
if (src != NULL) {
DEBUG("ipv6: set packet source to %s\n",
ipv6_addr_to_str(addr_str, src, sizeof(addr_str)));
memcpy(&hdr->src, src, sizeof(ipv6_addr_t));
}
/* Otherwise leave unspecified */
}
}
DEBUG("ipv6: calculate checksum for upper header.\n");
if ((res = gnrc_netreg_calc_csum(payload, ipv6)) < 0) {
if (res != -ENOENT) { /* if there is no checksum we are okay */
DEBUG("ipv6: checksum calculation failed.\n");
return res;
}
}
return 0;
}
static inline void _send_multicast_over_iface(kernel_pid_t iface, gnrc_pktsnip_t *pkt)
{
DEBUG("ipv6: send multicast over interface %" PRIkernel_pid "\n", iface);
/* mark as multicast */
((gnrc_netif_hdr_t *)pkt->data)->flags |= GNRC_NETIF_HDR_FLAGS_MULTICAST;
/* and send to interface */
_send_to_iface(iface, pkt);
}
static void _send_multicast(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
gnrc_pktsnip_t *ipv6, gnrc_pktsnip_t *payload,
bool prep_hdr)
{
kernel_pid_t ifs[GNRC_NETIF_NUMOF];
size_t ifnum = 0;
if (iface == KERNEL_PID_UNDEF) {
/* get list of interfaces */
ifnum = gnrc_netif_get(ifs);
/* throw away packet if no one is interested */
if (ifnum == 0) {
DEBUG("ipv6: no interfaces registered, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
}
#if GNRC_NETIF_NUMOF > 1
/* netif header not present: send over all interfaces */
if (iface == KERNEL_PID_UNDEF) {
assert(pkt == ipv6);
/* send packet to link layer */
gnrc_pktbuf_hold(pkt, ifnum - 1);
for (size_t i = 0; i < ifnum; i++) {
gnrc_pktsnip_t *netif;
if (prep_hdr) {
/* need to get second write access (duplication) to fill IPv6
* header interface-local */
gnrc_pktsnip_t *tmp = gnrc_pktbuf_start_write(pkt);
gnrc_pktsnip_t *ptr = tmp->next;
ipv6 = tmp;
if (ipv6 == NULL) {
DEBUG("ipv6: unable to get write access to IPv6 header, "
"for interface %" PRIkernel_pid "\n", ifs[i]);
gnrc_pktbuf_release(pkt);
return;
}
/* multiple interfaces => possibly different source addresses
* => different checksums => duplication of payload needed */
while (ptr != payload->next) {
/* duplicate everything including payload */
tmp->next = gnrc_pktbuf_start_write(ptr);
if (tmp->next == NULL) {
DEBUG("ipv6: unable to get write access to payload, drop it\n");
gnrc_pktbuf_release(ipv6);
return;
}
tmp = tmp->next;
ptr = ptr->next;
}
if (_fill_ipv6_hdr(ifs[i], ipv6, tmp) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(ipv6);
return;
}
}
/* allocate interface header */
netif = gnrc_netif_hdr_build(NULL, 0, NULL, 0);
if (netif == NULL) {
DEBUG("ipv6: error on interface header allocation, "
"dropping packet\n");
gnrc_pktbuf_release(ipv6);
return;
}
LL_PREPEND(ipv6, netif);
_send_multicast_over_iface(ifs[i], ipv6);
}
}
else {
/* iface != KERNEL_PID_UNDEF implies that netif header is present */
assert(pkt != ipv6);
if (prep_hdr) {
if (_fill_ipv6_hdr(iface, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_multicast_over_iface(iface, pkt);
}
#else /* GNRC_NETIF_NUMOF */
(void)ifnum; /* not used in this build branch */
if (iface == KERNEL_PID_UNDEF) {
gnrc_pktsnip_t *netif;
iface = ifs[0];
/* allocate interface header */
netif = gnrc_netif_hdr_build(NULL, 0, NULL, 0);
if (netif == NULL) {
DEBUG("ipv6: error on interface header allocation, "
"dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
LL_PREPEND(pkt, netif);
}
if (prep_hdr) {
if (_fill_ipv6_hdr(iface, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_multicast_over_iface(iface, pkt);
#endif /* GNRC_NETIF_NUMOF */
}
static inline kernel_pid_t _next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
kernel_pid_t iface, ipv6_addr_t *dst,
gnrc_pktsnip_t *pkt)
{
kernel_pid_t found_iface;
#if defined(MODULE_GNRC_SIXLOWPAN_ND)
(void)pkt;
found_iface = gnrc_sixlowpan_nd_next_hop_l2addr(l2addr, l2addr_len, iface, dst);
if (found_iface > KERNEL_PID_UNDEF) {
return found_iface;
}
#endif
#if defined(MODULE_GNRC_NDP_NODE)
found_iface = gnrc_ndp_node_next_hop_l2addr(l2addr, l2addr_len, iface, dst, pkt);
#elif !defined(MODULE_GNRC_SIXLOWPAN_ND) && defined(MODULE_GNRC_IPV6_NC)
(void)pkt;
gnrc_ipv6_nc_t *nc = gnrc_ipv6_nc_get(iface, dst);
found_iface = gnrc_ipv6_nc_get_l2_addr(l2addr, l2addr_len, nc);
#elif !defined(MODULE_GNRC_SIXLOWPAN_ND)
found_iface = KERNEL_PID_UNDEF;
(void)l2addr;
(void)l2addr_len;
(void)iface;
(void)dst;
(void)pkt;
*l2addr_len = 0;
#endif
return found_iface;
}
static void _send(gnrc_pktsnip_t *pkt, bool prep_hdr)
{
kernel_pid_t iface = KERNEL_PID_UNDEF;
gnrc_pktsnip_t *ipv6, *payload;
ipv6_addr_t *tmp;
ipv6_hdr_t *hdr;
/* get IPv6 snip and (if present) generic interface header */
if (pkt->type == GNRC_NETTYPE_NETIF) {
/* If there is already a netif header (routing protocols and
* neighbor discovery might add them to preset sending interface) */
iface = ((gnrc_netif_hdr_t *)pkt->data)->if_pid;
/* seize payload as temporary variable */
ipv6 = gnrc_pktbuf_start_write(pkt); /* write protect for later removal
* in _send_unicast() */
if (ipv6 == NULL) {
DEBUG("ipv6: unable to get write access to netif header, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = ipv6; /* Reset pkt from temporary variable */
ipv6 = pkt->next;
}
else {
ipv6 = pkt;
}
/* seize payload as temporary variable */
payload = gnrc_pktbuf_start_write(ipv6);
if (payload == NULL) {
DEBUG("ipv6: unable to get write access to IPv6 header, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
if (ipv6 != pkt) { /* in case packet has netif header */
pkt->next = payload;/* pkt is already write-protected so we can do that */
}
else {
pkt = payload; /* pkt is the IPv6 header so we just write-protected it */
}
ipv6 = payload; /* Reset ipv6 from temporary variable */
hdr = ipv6->data;
payload = ipv6->next;
if (ipv6_addr_is_multicast(&hdr->dst)) {
_send_multicast(iface, pkt, ipv6, payload, prep_hdr);
}
else if ((ipv6_addr_is_loopback(&hdr->dst)) || /* dst is loopback address */
((iface == KERNEL_PID_UNDEF) && /* or dst registered to any local interface */
((iface = gnrc_ipv6_netif_find_by_addr(&tmp, &hdr->dst)) != KERNEL_PID_UNDEF)) ||
((iface != KERNEL_PID_UNDEF) && /* or dst registered to given interface */
(gnrc_ipv6_netif_find_addr(iface, &hdr->dst) != NULL))) {
uint8_t *rcv_data;
gnrc_pktsnip_t *ptr = ipv6, *rcv_pkt;
if (prep_hdr) {
if (_fill_ipv6_hdr(iface, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
rcv_pkt = gnrc_pktbuf_add(NULL, NULL, gnrc_pkt_len(ipv6), GNRC_NETTYPE_IPV6);
if (rcv_pkt == NULL) {
DEBUG("ipv6: error on generating loopback packet\n");
gnrc_pktbuf_release(pkt);
return;
}
rcv_data = rcv_pkt->data;
/* "reverse" packet (by making it one snip as if received from NIC) */
while (ptr != NULL) {
memcpy(rcv_data, ptr->data, ptr->size);
rcv_data += ptr->size;
ptr = ptr->next;
}
gnrc_pktbuf_release(pkt);
DEBUG("ipv6: packet is addressed to myself => loopback\n");
if (gnrc_netapi_receive(gnrc_ipv6_pid, rcv_pkt) < 1) {
DEBUG("ipv6: unable to deliver packet\n");
gnrc_pktbuf_release(rcv_pkt);
}
}
else {
uint8_t l2addr_len = GNRC_IPV6_NC_L2_ADDR_MAX;
uint8_t l2addr[l2addr_len];
iface = _next_hop_l2addr(l2addr, &l2addr_len, iface, &hdr->dst, pkt);
if (iface == KERNEL_PID_UNDEF) {
DEBUG("ipv6: error determining next hop's link layer address\n");
gnrc_pktbuf_release(pkt);
return;
}
if (prep_hdr) {
if (_fill_ipv6_hdr(iface, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_unicast(iface, l2addr, l2addr_len, pkt);
}
}
/* functions for receiving */
static inline bool _pkt_not_for_me(kernel_pid_t *iface, ipv6_hdr_t *hdr)
{
if (ipv6_addr_is_loopback(&hdr->dst)) {
return false;
}
else if ((!ipv6_addr_is_link_local(&hdr->dst)) ||
(*iface == KERNEL_PID_UNDEF)) {
kernel_pid_t if_pid = gnrc_ipv6_netif_find_by_addr(NULL, &hdr->dst);
if (*iface == KERNEL_PID_UNDEF) {
*iface = if_pid; /* Use original interface for reply if
* existent */
}
return (if_pid == KERNEL_PID_UNDEF);
}
else {
return (gnrc_ipv6_netif_find_addr(*iface, &hdr->dst) == NULL);
}
}
static void _dispatch_rcv_pkt(gnrc_nettype_t type, uint32_t demux_ctx,
gnrc_pktsnip_t *pkt)
{
gnrc_netreg_entry_t *entry = gnrc_netreg_lookup(type, demux_ctx);
while (entry) {
DEBUG("ipv6: Send receive command for %p to %" PRIu16 "\n", (void *)pkt,
entry->pid);
if (gnrc_netapi_receive(entry->pid, pkt) < 1) {
DEBUG("ipv6: unable to deliver packet\n");
gnrc_pktbuf_release(pkt);
}
entry = gnrc_netreg_getnext(entry);
}
}
static void _receive(gnrc_pktsnip_t *pkt)
{
kernel_pid_t iface = KERNEL_PID_UNDEF;
gnrc_pktsnip_t *ipv6, *netif, *first_ext;
ipv6_hdr_t *hdr;
assert(pkt != NULL);
netif = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_NETIF);
assert(netif);
iface = ((gnrc_netif_hdr_t *)netif->data)->if_pid;
first_ext = pkt;
for (ipv6 = pkt; ipv6 != NULL; ipv6 = ipv6->next) { /* find IPv6 header if already marked */
if ((ipv6->type == GNRC_NETTYPE_IPV6) && (ipv6->size == sizeof(ipv6_hdr_t)) &&
(ipv6_hdr_is(ipv6->data))) {
break;
}
first_ext = ipv6;
}
if (ipv6 == NULL) {
if (!ipv6_hdr_is(pkt->data)) {
DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
#ifdef MODULE_GNRC_IPV6_WHITELIST
if (!gnrc_ipv6_whitelisted(&((ipv6_hdr_t *)(pkt->data))->src)) {
DEBUG("ipv6: Source address not whitelisted, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
#endif
#ifdef MODULE_GNRC_IPV6_BLACKLIST
if (gnrc_ipv6_blacklisted(&((ipv6_hdr_t *)(pkt->data))->src)) {
DEBUG("ipv6: Source address blacklisted, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
#endif
/* seize ipv6 as a temporary variable */
ipv6 = gnrc_pktbuf_start_write(pkt);
if (ipv6 == NULL) {
DEBUG("ipv6: unable to get write access to packet, drop it\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = ipv6; /* reset pkt from temporary variable */
ipv6 = gnrc_pktbuf_mark(pkt, sizeof(ipv6_hdr_t), GNRC_NETTYPE_IPV6);
first_ext = pkt;
if (ipv6 == NULL) {
DEBUG("ipv6: error marking IPv6 header, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
}
#ifdef MODULE_GNRC_IPV6_WHITELIST
else if (!gnrc_ipv6_whitelisted(&((ipv6_hdr_t *)(ipv6->data))->src)) {
/* if ipv6 header already marked*/
DEBUG("ipv6: Source address not whitelisted, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
#endif
#ifdef MODULE_GNRC_IPV6_BLACKLIST
else if (gnrc_ipv6_blacklisted(&((ipv6_hdr_t *)(ipv6->data))->src)) {
/* if ipv6 header already marked*/
DEBUG("ipv6: Source address blacklisted, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
#endif
/* extract header */
hdr = (ipv6_hdr_t *)ipv6->data;
/* if available, remove any padding that was added by lower layers
* to fulfill their minimum size requirements (e.g. ethernet) */
if (byteorder_ntohs(hdr->len) < pkt->size) {
gnrc_pktbuf_realloc_data(pkt, byteorder_ntohs(hdr->len));
}
DEBUG("ipv6: Received (src = %s, ",
ipv6_addr_to_str(addr_str, &(hdr->src), sizeof(addr_str)));
DEBUG("dst = %s, next header = %u, length = %" PRIu16 ")\n",
ipv6_addr_to_str(addr_str, &(hdr->dst), sizeof(addr_str)),
hdr->nh, byteorder_ntohs(hdr->len));
if (_pkt_not_for_me(&iface, hdr)) { /* if packet is not for me */
DEBUG("ipv6: packet destination not this host\n");
#ifdef MODULE_GNRC_IPV6_ROUTER /* only routers redirect */
/* redirect to next hop */
DEBUG("ipv6: decrement hop limit to %u\n", (uint8_t) (hdr->hl - 1));
/* RFC 4291, section 2.5.6 states: "Routers must not forward any
* packets with Link-Local source or destination addresses to other
* links."
*/
if ((ipv6_addr_is_link_local(&(hdr->src))) || (ipv6_addr_is_link_local(&(hdr->dst)))) {
DEBUG("ipv6: do not forward packets with link-local source or"\
" destination address\n");
gnrc_pktbuf_release(pkt);
return;
}
/* TODO: check if receiving interface is router */
else if (--(hdr->hl) > 0) { /* drop packets that *reach* Hop Limit 0 */
gnrc_pktsnip_t *reversed_pkt = NULL, *ptr = pkt;
DEBUG("ipv6: forward packet to next hop\n");
/* pkt might not be writable yet, if header was given above */
ipv6 = gnrc_pktbuf_start_write(ipv6);
if (ipv6 == NULL) {
DEBUG("ipv6: unable to get write access to packet: dropping it\n");
gnrc_pktbuf_release(pkt);
return;
}
/* remove L2 headers around IPV6 */
netif = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_NETIF);
if (netif != NULL) {
gnrc_pktbuf_remove_snip(pkt, netif);
}
/* reverse packet snip list order */
while (ptr != NULL) {
gnrc_pktsnip_t *next;
ptr = gnrc_pktbuf_start_write(ptr); /* duplicate if not already done */
if (ptr == NULL) {
DEBUG("ipv6: unable to get write access to packet: dropping it\n");
gnrc_pktbuf_release(reversed_pkt);
gnrc_pktbuf_release(pkt);
return;
}
next = ptr->next;
ptr->next = reversed_pkt;
reversed_pkt = ptr;
ptr = next;
}
_send(reversed_pkt, false);
return;
}
else {
DEBUG("ipv6: hop limit reached 0: drop packet\n");
gnrc_pktbuf_release(pkt);
return;
}
#else /* MODULE_GNRC_IPV6_ROUTER */
DEBUG("ipv6: dropping packet\n");
/* non rounting hosts just drop the packet */
gnrc_pktbuf_release(pkt);
return;
#endif /* MODULE_GNRC_IPV6_ROUTER */
}
/* IPv6 internal demuxing (ICMPv6, Extension headers etc.) */
gnrc_ipv6_demux(iface, first_ext, pkt, hdr->nh);
}
static void _decapsulate(gnrc_pktsnip_t *pkt)
{
gnrc_pktsnip_t *ptr = pkt;
pkt->type = GNRC_NETTYPE_UNDEF; /* prevent payload (the encapsulated packet)
* from being removed */
/* Remove encapsulating IPv6 header */
while ((ptr->next != NULL) && (ptr->next->type == GNRC_NETTYPE_IPV6)) {
gnrc_pktbuf_remove_snip(pkt, pkt->next);
}
pkt->type = GNRC_NETTYPE_IPV6;
_receive(pkt);
}
/** @} */
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