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861035f22d
RIOT/sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c
Martine Lenders 861035f22d gnrc: integrate gnrc_netif2 
Not link-able, since NDP and NC are missing (intentionally)
2017-11-07 19:08:44 +01:00

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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"
#ifndef MODULE_GNRC_IPV6_NIB
#include "net/gnrc/ipv6/nc.h"
#else
#include "net/gnrc/ipv6/nib.h"
#endif
#include "net/gnrc/netif2/internal.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);
/* 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;
}
static void _dispatch_next_header(gnrc_pktsnip_t *current, gnrc_pktsnip_t *pkt,
uint8_t nh, bool interested);
/*
* 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)
{
bool interested = false;
current->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;
#ifdef MODULE_GNRC_SIXLOWPAN_IPHC_NHC
/* second statement is true for small 6LoWPAN NHC decompressed frames
* since in this case it looks like
*
* * GNRC_NETTYPE_UNDEF <- pkt
* v
* * GNRC_NETTYPE_UDP <- current
* v
* * GNRC_NETTYPE_EXT
* v
* * GNRC_NETTYPE_IPV6
*/
assert((current == pkt) || (current == pkt->next));
#else
assert(current == pkt);
#endif
break;
}
_dispatch_next_header(current, pkt, nh, interested);
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);
return;
#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:
assert(false);
break;
}
assert(false);
}
ipv6_hdr_t *gnrc_ipv6_get_header(gnrc_pktsnip_t *pkt)
{
ipv6_hdr_t *hdr = NULL;
gnrc_pktsnip_t *tmp = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_IPV6);
if ((tmp) && ipv6_hdr_is(tmp->data)) {
hdr = ((ipv6_hdr_t*) tmp->data);
}
return hdr;
}
/* internal functions */
static void _dispatch_next_header(gnrc_pktsnip_t *current, gnrc_pktsnip_t *pkt,
uint8_t nh, bool interested)
{
#ifdef MODULE_GNRC_IPV6_EXT
const bool should_dispatch_current_type = ((current->type != GNRC_NETTYPE_IPV6_EXT) ||
(current->next->type == GNRC_NETTYPE_IPV6));
#else
const bool should_dispatch_current_type = (current->next->type == GNRC_NETTYPE_IPV6);
#endif
DEBUG("ipv6: forward nh = %u to other threads\n", nh);
/* dispatch IPv6 extension header only once */
if (should_dispatch_current_type) {
bool should_release = (gnrc_netreg_num(GNRC_NETTYPE_IPV6, nh) == 0) &&
(!interested);
if (!should_release) {
gnrc_pktbuf_hold(pkt, 1); /* don't remove from packet buffer in
* next dispatch */
}
if (gnrc_netapi_dispatch_receive(current->type,
GNRC_NETREG_DEMUX_CTX_ALL,
pkt) == 0) {
gnrc_pktbuf_release(pkt);
}
if (should_release) {
return;
}
}
if (interested) {
gnrc_pktbuf_hold(pkt, 1); /* don't remove from packet buffer in
* next dispatch */
}
if (gnrc_netapi_dispatch_receive(GNRC_NETTYPE_IPV6, nh, pkt) == 0) {
gnrc_pktbuf_release(pkt);
}
}
static void *_event_loop(void *args)
{
msg_t msg, reply, msg_q[GNRC_IPV6_MSG_QUEUE_SIZE];
gnrc_netreg_entry_t me_reg = GNRC_NETREG_ENTRY_INIT_PID(GNRC_NETREG_DEMUX_CTX_ALL,
sched_active_pid);
(void)args;
msg_init_queue(msg_q, GNRC_IPV6_MSG_QUEUE_SIZE);
/* 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(msg.content.ptr);
break;
case GNRC_NETAPI_MSG_TYPE_SND:
DEBUG("ipv6: GNRC_NETAPI_MSG_TYPE_SND received\n");
_send(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;
#ifndef MODULE_GNRC_IPV6_NIB
#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, */
/* 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(msg.content.ptr);
break;
case GNRC_NDP_MSG_NC_STATE_TIMEOUT:
DEBUG("ipv6: Neigbor cache state timeout received\n");
gnrc_ndp_state_timeout(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(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(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(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(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(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(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(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 = msg.content.ptr;
gnrc_ndp_internal_send_rtr_adv(nc_entry->iface, NULL,
&(nc_entry->ipv6_addr), false);
break;
#endif
#else /* MODULE_GNRC_IPV6_NIB */
case GNRC_IPV6_NIB_SND_UC_NS:
case GNRC_IPV6_NIB_SND_MC_NS:
case GNRC_IPV6_NIB_SND_NA:
case GNRC_IPV6_NIB_SEARCH_RTR:
case GNRC_IPV6_NIB_RECONFIRM_RTR:
case GNRC_IPV6_NIB_REPLY_RS:
case GNRC_IPV6_NIB_SND_MC_RA:
case GNRC_IPV6_NIB_REACH_TIMEOUT:
case GNRC_IPV6_NIB_DELAY_TIMEOUT:
case GNRC_IPV6_NIB_ADDR_REG_TIMEOUT:
case GNRC_IPV6_NIB_6LO_CTX_TIMEOUT:
case GNRC_IPV6_NIB_ABR_TIMEOUT:
case GNRC_IPV6_NIB_PFX_TIMEOUT:
case GNRC_IPV6_NIB_RTR_TIMEOUT:
case GNRC_IPV6_NIB_RECALC_REACH_TIME:
DEBUG("ipv6: NIB timer event received\n");
gnrc_ipv6_nib_handle_timer_event(msg.content.ptr, msg.type);
break;
#endif /* MODULE_GNRC_IPV6_NIB */
default:
break;
}
}
return NULL;
}
static void _send_to_iface(gnrc_netif2_t *netif, gnrc_pktsnip_t *pkt)
{
assert(netif != NULL);
((gnrc_netif_hdr_t *)pkt->data)->if_pid = netif->pid;
if (gnrc_pkt_len(pkt->next) > netif->ipv6.mtu) {
DEBUG("ipv6: packet too big\n");
gnrc_pktbuf_release(pkt);
return;
}
#ifdef MODULE_NETSTATS_IPV6
netif->ipv6.stats.tx_success++;
netif->ipv6.stats.tx_bytes += gnrc_pkt_len(pkt->next);
#endif
#ifdef MODULE_GNRC_SIXLOWPAN
if (gnrc_netif2_is_6ln(netif)) {
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\n");
gnrc_pktbuf_release(pkt);
}
return;
}
#endif
if (gnrc_netapi_send(netif->pid, pkt) < 1) {
DEBUG("ipv6: unable to send packet\n");
gnrc_pktbuf_release(pkt);
}
}
static gnrc_pktsnip_t *_create_netif_hdr(uint8_t *dst_l2addr,
uint16_t dst_l2addr_len,
gnrc_pktsnip_t *pkt)
{
gnrc_pktsnip_t *netif_hdr = gnrc_netif_hdr_build(NULL, 0, dst_l2addr, dst_l2addr_len);
if (netif_hdr == NULL) {
DEBUG("ipv6: error on interface header allocation, dropping packet\n");
gnrc_pktbuf_release(pkt);
return NULL;
}
if (pkt->type == GNRC_NETTYPE_NETIF) {
/* remove old netif header, since checking it for correctness would
* cause to much overhead.
* netif header might have been allocated by some higher layer either
* to set a sending interface or some flags. Interface was already
* copied using netif parameter, so we only need to copy the flags
* (minus the broadcast/multicast flags) */
DEBUG("ipv6: copy old interface header flags\n");
gnrc_netif_hdr_t *netif_new = netif_hdr->data, *netif_old = pkt->data;
netif_new->flags = netif_old->flags & \
~(GNRC_NETIF_HDR_FLAGS_BROADCAST | GNRC_NETIF_HDR_FLAGS_MULTICAST);
DEBUG("ipv6: removed old interface header\n");
pkt = gnrc_pktbuf_remove_snip(pkt, pkt);
}
/* add netif_hdr to front of the pkt list */
LL_PREPEND(pkt, netif_hdr);
return pkt;
}
/* functions for sending */
static void _send_unicast(gnrc_netif2_t *netif, uint8_t *dst_l2addr,
uint16_t dst_l2addr_len, gnrc_pktsnip_t *pkt)
{
DEBUG("ipv6: add interface header to packet\n");
if ((pkt = _create_netif_hdr(dst_l2addr, dst_l2addr_len, pkt)) == NULL) {
return;
}
DEBUG("ipv6: send unicast over interface %" PRIkernel_pid "\n", netif->pid);
/* and send to interface */
#ifdef MODULE_NETSTATS_IPV6
netif->ipv6.stats.tx_unicast_count++;
#endif
_send_to_iface(netif, pkt);
}
static int _fill_ipv6_hdr(gnrc_netif2_t *netif, 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 (netif == NULL) {
hdr->hl = GNRC_IPV6_NETIF_DEFAULT_HL;
}
else {
hdr->hl = netif->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_netif2_ipv6_addr_best_src(netif, &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(gnrc_netif2_t *netif,
gnrc_pktsnip_t *pkt)
{
DEBUG("ipv6: send multicast over interface %" PRIkernel_pid "\n", netif->pid);
/* mark as multicast */
((gnrc_netif_hdr_t *)pkt->data)->flags |= GNRC_NETIF_HDR_FLAGS_MULTICAST;
#ifdef MODULE_NETSTATS_IPV6
netif->ipv6.stats.tx_mcast_count++;
#endif
/* and send to interface */
_send_to_iface(netif, pkt);
}
static void _send_multicast(gnrc_netif2_t *netif, gnrc_pktsnip_t *pkt,
gnrc_pktsnip_t *ipv6, gnrc_pktsnip_t *payload,
bool prep_hdr)
{
size_t ifnum = 0;
if (netif == NULL) {
ifnum = gnrc_netif2_numof();
/* 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
/* interface not given: send over all interfaces */
if (netif == NULL) {
/* send packet to link layer */
gnrc_pktbuf_hold(pkt, ifnum - 1);
while ((netif = gnrc_netif2_iter(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", netif->pid);
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(netif, ipv6, tmp) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(ipv6);
return;
}
}
if ((ipv6 = _create_netif_hdr(NULL, 0, ipv6)) == NULL) {
return;
}
_send_multicast_over_iface(netif, ipv6);
}
}
else {
if (prep_hdr) {
if (_fill_ipv6_hdr(netif, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_multicast_over_iface(netif, pkt);
}
#else /* GNRC_NETIF_NUMOF */
(void)ifnum; /* not used in this build branch */
if (netif == NULL) {
netif = gnrc_netif2_iter(NULL);
/* allocate interface header */
if ((pkt = _create_netif_hdr(NULL, 0, pkt)) == NULL) {
return;
}
}
if (prep_hdr) {
if (_fill_ipv6_hdr(netif, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_multicast_over_iface(netif, pkt);
#endif /* GNRC_NETIF_NUMOF */
}
#ifndef MODULE_GNRC_IPV6_NIB
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;
}
#endif /* MODULE_GNRC_IPV6_NIB */
static void _send(gnrc_pktsnip_t *pkt, bool prep_hdr)
{
kernel_pid_t iface = KERNEL_PID_UNDEF;
gnrc_pktsnip_t *ipv6, *payload;
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;
gnrc_netif2_t *netif = (iface == KERNEL_PID_UNDEF) ?
NULL :
gnrc_netif2_get_by_pid(iface);
if (ipv6_addr_is_multicast(&hdr->dst)) {
_send_multicast(netif, 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 */
((netif = gnrc_netif2_get_by_ipv6_addr(&hdr->dst)) != NULL)
) || ((iface != KERNEL_PID_UNDEF) && /* or dst registered to given interface */
(gnrc_netif2_ipv6_addr_idx(netif, &hdr->dst) > 0)
)) {
uint8_t *rcv_data;
gnrc_pktsnip_t *ptr = ipv6, *rcv_pkt;
if (prep_hdr) {
if (_fill_ipv6_hdr(netif, 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 {
#ifndef MODULE_GNRC_IPV6_NIB
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;
}
netif = gnrc_netif2_get_by_pid(iface);
assert(netif != NULL);
if (prep_hdr) {
if (_fill_ipv6_hdr(netif, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_unicast(netif, l2addr, l2addr_len, pkt);
#else /* MODULE_GNRC_IPV6_NIB */
gnrc_ipv6_nib_nc_t nce;
if (gnrc_ipv6_nib_get_next_hop_l2addr(&hdr->dst, iface, pkt,
&nce) < 0) {
/* packet is released by NIB */
return;
}
iface = gnrc_ipv6_nib_nc_get_iface(&nce);
netif = gnrc_netif2_get_by_pid(iface);
assert(netif != NULL);
if (prep_hdr) {
if (_fill_ipv6_hdr(netif, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
_send_unicast(netif, nce.l2addr,
nce.l2addr_len, pkt);
#endif /* MODULE_GNRC_IPV6_NIB */
}
}
/* 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)) {
gnrc_netif2_t *netif = gnrc_netif2_get_by_ipv6_addr(&hdr->dst);
if (*iface == KERNEL_PID_UNDEF) {
/* Use original interface for reply if existent */
*iface = (netif != NULL) ? netif->pid : KERNEL_PID_UNDEF;
}
return (netif == NULL);
}
else {
return (gnrc_netif2_get_by_ipv6_addr(&hdr->dst) == NULL);
}
}
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);
if (netif != NULL) {
iface = ((gnrc_netif_hdr_t *)netif->data)->if_pid;
#ifdef MODULE_NETSTATS_IPV6
assert(iface);
netstats_t *stats = &(gnrc_netif2_get_by_pid(iface)->ipv6.stats);
stats->rx_count++;
stats->rx_bytes += (gnrc_pkt_len(pkt) - netif->size);
#endif
}
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;
pkt->type = GNRC_NETTYPE_UNDEF; /* snip is no longer IPv6 */
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));
}
else if (byteorder_ntohs(hdr->len) >
(gnrc_pkt_len_upto(pkt, GNRC_NETTYPE_IPV6) - sizeof(ipv6_hdr_t))) {
DEBUG("ipv6: invalid payload length: %d, actual: %d, dropping packet\n",
(int) byteorder_ntohs(hdr->len),
(int) (gnrc_pkt_len_upto(pkt, GNRC_NETTYPE_IPV6) - sizeof(ipv6_hdr_t)));
gnrc_pktbuf_release(pkt);
return;
}
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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