static void test_pktbuf_start_write__pkt_users_1(void)
{
gnrc_pktsnip_t *pkt_copy, *pkt = gnrc_pktbuf_add(NULL, TEST_STRING16, sizeof(TEST_STRING16),
GNRC_NETTYPE_TEST);
TEST_ASSERT_NOT_NULL((pkt_copy = gnrc_pktbuf_start_write(pkt)));
TEST_ASSERT(pkt == pkt_copy);
gnrc_pktbuf_release(pkt);
TEST_ASSERT(gnrc_pktbuf_is_empty());
}
static void test_pktbuf_start_write__pkt_users_2(void)
{
gnrc_pktsnip_t *pkt_copy, *pkt = gnrc_pktbuf_add(NULL, TEST_STRING16, sizeof(TEST_STRING16),
GNRC_NETTYPE_TEST);
gnrc_pktbuf_hold(pkt, 1);
TEST_ASSERT_NOT_NULL((pkt_copy = gnrc_pktbuf_start_write(pkt)));
TEST_ASSERT(pkt != pkt_copy);
TEST_ASSERT(pkt->next == pkt_copy->next);
TEST_ASSERT_EQUAL_STRING(pkt->data, pkt_copy->data);
TEST_ASSERT_EQUAL_INT(pkt->size, pkt_copy->size);
TEST_ASSERT_EQUAL_INT(pkt->type, pkt_copy->type);
TEST_ASSERT_EQUAL_INT(pkt->users, pkt_copy->users);
TEST_ASSERT_EQUAL_INT(1, pkt->users);
gnrc_pktbuf_release(pkt_copy);
gnrc_pktbuf_release(pkt);
TEST_ASSERT(gnrc_pktbuf_is_empty());
}
/**
* @brief marks IPv6 extension header if needed.
* updates pkt and returns next header.
* @param[in] current The current header
* @param[in,out] pkt The whole packet
* @return The next header
* @return NULL on error
*/
static gnrc_pktsnip_t *_mark_extension_header(gnrc_pktsnip_t *current,
gnrc_pktsnip_t **pkt)
{
gnrc_pktsnip_t *ext_snip, *tmp, *next;
ipv6_ext_t *ext = (ipv6_ext_t *) current->data;
size_t offset = ((ext->len * IPV6_EXT_LEN_UNIT) + IPV6_EXT_LEN_UNIT);
if (current == *pkt) {
if ((tmp = gnrc_pktbuf_start_write(*pkt)) == NULL) {
DEBUG("ipv6: could not get a copy of pkt\n");
gnrc_pktbuf_release(*pkt);
return NULL;
}
*pkt = tmp;
ext_snip = gnrc_pktbuf_mark(*pkt, offset, GNRC_NETTYPE_IPV6_EXT);
next = *pkt;
if (ext_snip == NULL) {
gnrc_pktbuf_release(*pkt);
return NULL;
}
}
else {
/* the header is already marked */
next = NULL;
for (tmp = *pkt; tmp != NULL; tmp = tmp->next) {
if (tmp->next == current) {
next = tmp;
break;
}
}
assert(next != NULL);
}
return next;
}
static void test_pktbuf_start_write__NULL(void)
{
gnrc_pktbuf_start_write(NULL);
TEST_ASSERT(gnrc_pktbuf_is_empty());
}
bool gnrc_ipv6_ext_demux(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
uint8_t nh)
{
gnrc_pktsnip_t *ext_snip, *tmp;
ipv6_ext_t *ext;
unsigned int offset = 0;
ipv6_hdr_t *hdr;
int res;
ext = ((ipv6_ext_t *)(((uint8_t *)pkt->data) + sizeof(ipv6_hdr_t)));
bool c = true;
while (c) {
switch (nh) {
case PROTNUM_IPV6_EXT_HOPOPT:
case PROTNUM_IPV6_EXT_DST:
case PROTNUM_IPV6_EXT_RH:
if ((tmp = gnrc_pktbuf_start_write(pkt)) == NULL) {
DEBUG("ipv6: could not get a copy of pkt\n");
gnrc_pktbuf_release(pkt);
return false;
}
pkt = tmp;
hdr = pkt->data;
ext = (ipv6_ext_t *) (((uint8_t *) pkt->data) + sizeof(ipv6_hdr_t) + offset);
res = ipv6_ext_rh_process(hdr, (ipv6_ext_rh_t *)ext);
if (res == EXT_RH_CODE_ERROR) {
/* TODO: send ICMPv6 error codes */
gnrc_pktbuf_release(pkt);
return false;
}
else if (res == EXT_RH_CODE_FORWARD) {
/* forward packet */
if (!gnrc_netapi_dispatch_receive(GNRC_NETTYPE_IPV6, GNRC_NETREG_DEMUX_CTX_ALL,
pkt)) {
DEBUG("ipv6: could not dispatch packet to the ipv6 thread\n");
gnrc_pktbuf_release(pkt);
}
return false;
}
else if (res == EXT_RH_CODE_OK) {
nh = ext->nh;
offset += ((ext->len * IPV6_EXT_LEN_UNIT) + IPV6_EXT_LEN_UNIT);
ext = ipv6_ext_get_next((ipv6_ext_t *)ext);
}
break;
case PROTNUM_IPV6_EXT_FRAG:
case PROTNUM_IPV6_EXT_AH:
case PROTNUM_IPV6_EXT_ESP:
case PROTNUM_IPV6_EXT_MOB:
/* TODO: add handling of types */
nh = ext->nh;
offset += ((ext->len * IPV6_EXT_LEN_UNIT) + IPV6_EXT_LEN_UNIT);
ext = ipv6_ext_get_next((ipv6_ext_t *)ext);
break;
default:
c = false;
offset += ((ext->len * IPV6_EXT_LEN_UNIT) + IPV6_EXT_LEN_UNIT);
ext = ipv6_ext_get_next((ipv6_ext_t *)ext);
break;
}
}
ext_snip = gnrc_pktbuf_mark(pkt, offset, GNRC_NETTYPE_IPV6);
if (ext_snip == NULL) {
gnrc_pktbuf_release(pkt);
return false;
}
gnrc_ipv6_demux(iface, pkt, nh); /* demultiplex next header */
return true;
}
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_ipv6_netif_get_stats(iface);
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 _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);
}
}
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 */
}
void gnrc_rpl_p2p_recv_DRO(gnrc_pktsnip_t *pkt, ipv6_addr_t *src)
{
gnrc_pktsnip_t *icmpv6_snip = gnrc_pktbuf_mark(pkt, sizeof(icmpv6_hdr_t), GNRC_NETTYPE_ICMPV6);
gnrc_pktsnip_t *dro_snip = gnrc_pktbuf_mark(pkt, sizeof(gnrc_rpl_p2p_dro_t),
GNRC_NETTYPE_UNDEF);
gnrc_pktsnip_t *rdo_snip = gnrc_pktbuf_mark(pkt, sizeof(gnrc_rpl_p2p_opt_rdo_t),
GNRC_NETTYPE_UNDEF);
gnrc_pktsnip_t *addr_snip = pkt;
gnrc_rpl_instance_t *inst;
gnrc_rpl_dodag_t *dodag;
gnrc_rpl_p2p_ext_t *p2p_ext;
gnrc_rpl_p2p_dro_t *dro;
gnrc_rpl_p2p_opt_rdo_t *rdo;
uint8_t *addr_vec;
uint16_t flags;
size_t addr_len;
if (!rdo_snip || !dro_snip) {
DEBUG("RPL-P2P: Error - No DRO or RDO received\n");
gnrc_pktbuf_release(pkt);
return;
}
dro = dro_snip->data;
if ((inst = gnrc_rpl_instance_get(dro->instance_id)) == NULL) {
DEBUG("RPL-P2P: Error - Instance (%d) does not exist\n", dro->instance_id);
return;
}
dodag = &inst->dodag;
if ((p2p_ext = gnrc_rpl_p2p_ext_get(dodag)) == NULL) {
DEBUG("RPL-P2P: Error - No P2P-RPL DODAG extension found\n");
return;
}
if (p2p_ext->for_me) {
DEBUG("RPL-P2P: Ignore DRO\n");
return;
}
flags = byteorder_ntohs(dro->flags_rev);
p2p_ext->stop = (flags & (1 << GNRC_RPL_P2P_DRO_FLAGS_STOP)) >> GNRC_RPL_P2P_DRO_FLAGS_STOP;
p2p_ext->dro_ack = (flags & (1 << GNRC_RPL_P2P_DRO_FLAGS_ACK)) >> GNRC_RPL_P2P_DRO_FLAGS_ACK;
p2p_ext->dro_seq = (flags & (0x3 << GNRC_RPL_P2P_DRO_FLAGS_SEQ)) >> GNRC_RPL_P2P_DRO_FLAGS_SEQ;
addr_len = sizeof(ipv6_addr_t) - p2p_ext->compr;
ipv6_addr_t addr = p2p_ext->dodag->dodag_id;
ipv6_addr_t *me = NULL;
addr_vec = addr_snip->data;
rdo = rdo_snip->data;
if (rdo->lmn > 0) {
rdo->lmn--;
memcpy(&addr.u8[p2p_ext->compr], &addr_vec[addr_len * rdo->lmn], addr_len);
}
if (gnrc_ipv6_netif_find_by_addr(&me, &addr) == dodag->iface) {
gnrc_ipv6_nib_ft_add(&p2p_ext->target, IPV6_ADDR_BIT_LEN, src, dodag->iface,
p2p_ext->dodag->default_lifetime *
p2p_ext->dodag->lifetime_unit);
if (p2p_ext->dodag->node_status != GNRC_RPL_ROOT_NODE) {
if ((rdo_snip = gnrc_pktbuf_start_write(rdo_snip)) == NULL) {
DEBUG("RPL-P2P: Error - Cannot allocate new RDO\n");
return;
}
addr_snip->next = NULL;
rdo_snip->next = addr_snip;
dro_snip->next = rdo_snip;
icmpv6_snip = gnrc_icmpv6_build(dro_snip, ICMPV6_RPL_CTRL, GNRC_RPL_P2P_ICMPV6_CODE_DRO,
sizeof(icmpv6_hdr_t));
if (icmpv6_snip == NULL) {
DEBUG("RPL-P2P: cannot allocate ICMPv6 - no space left in packet buffer\n");
gnrc_pktbuf_release(pkt);
return;
}
gnrc_rpl_send(icmpv6_snip, p2p_ext->dodag->iface, NULL, NULL, &p2p_ext->dodag->dodag_id);
return;
}
}
gnrc_pktbuf_release(pkt);
return;
}
static void _receive(gnrc_pktsnip_t *pkt)
{
kernel_pid_t iface = KERNEL_PID_UNDEF;
gnrc_pktsnip_t *ipv6, *netif;
ipv6_hdr_t *hdr;
assert(pkt != NULL);
LL_SEARCH_SCALAR(pkt, netif, type, GNRC_NETTYPE_NETIF);
if (netif != NULL) {
iface = ((gnrc_netif_hdr_t *)netif->data)->if_pid;
}
if ((pkt->next != NULL) && (pkt->next->type == GNRC_NETTYPE_IPV6) &&
(pkt->next->size == sizeof(ipv6_hdr_t))) {
/* IP header was already marked. Take it. */
ipv6 = pkt->next;
if (!ipv6_hdr_is(ipv6->data)) {
DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
}
else {
if (!ipv6_hdr_is(pkt->data)) {
DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
/* 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);
if (ipv6 == NULL) {
DEBUG("ipv6: error marking IPv6 header, dropping packet\n");
gnrc_pktbuf_release(pkt);
return;
}
}
/* 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 = %" PRIu8 ", 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 %" PRIu8 "\n", 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 *tmp = pkt;
DEBUG("ipv6: forward packet to next hop\n");
/* pkt might not be writable yet, if header was given above */
pkt = gnrc_pktbuf_start_write(tmp);
ipv6 = gnrc_pktbuf_start_write(ipv6);
if ((ipv6 == NULL) || (pkt == NULL)) {
DEBUG("ipv6: unable to get write access to packet: dropping it\n");
gnrc_pktbuf_release(tmp);
return;
}
gnrc_pktbuf_release(ipv6->next); /* remove headers around IPV6 */
ipv6->next = pkt; /* reorder for sending */
pkt->next = NULL;
_send(ipv6, 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, pkt, hdr->nh);
}
static void _send_multicast(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
gnrc_pktsnip_t *ipv6, gnrc_pktsnip_t *payload,
bool prep_hdr)
{
gnrc_pktsnip_t *netif;
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) {
/* send packet to link layer */
gnrc_pktbuf_hold(pkt, ifnum - 1);
for (size_t i = 0; i < ifnum; i++) {
if (prep_hdr) {
/* need to get second write access (duplication) to fill IPv6
* header interface-local */
ipv6 = gnrc_pktbuf_start_write(ipv6);
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;
}
if (_fill_ipv6_hdr(ifs[i], ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
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(pkt);
return;
}
LL_PREPEND(pkt, netif);
_send_multicast_over_iface(ifs[i], pkt, netif);
}
}
else {
/* iface != KERNEL_PID_UNDEF implies that netif header is present */
if (prep_hdr) {
if (_fill_ipv6_hdr(iface, ipv6, payload) < 0) {
/* error on filling up header */
gnrc_pktbuf_release(pkt);
return;
}
}
netif = pkt;
_send_multicast_over_iface(iface, pkt, netif);
}
#else /* GNRC_NETIF_NUMOF */
(void)ifnum; /* not used in this build branch */
if (iface == KERNEL_PID_UNDEF) {
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);
}
else {
netif = pkt;
}
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, netif);
#endif /* GNRC_NETIF_NUMOF */
}
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 %zu (network byteorder %04" PRIx16 ")\n",
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 %" PRIu8 "\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);
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 GNRC_NETIF_NUMOF > 1
if (payload->users > 1) {
gnrc_pktsnip_t *ptr = ipv6;
/* We deal with multiple interfaces here (multicast) => possible
* different source addresses => duplication of payload needed */
while (ptr != payload->next) {
gnrc_pktsnip_t *old = ptr->next;
/* duplicate everything including payload */
ptr->next = gnrc_pktbuf_start_write(ptr->next);
if (ptr->next == NULL) {
DEBUG("ipv6: unable to get write access to payload, drop it\n");
return -ENOBUFS;
}
ptr = old;
}
}
#endif /* GNRC_NETIF_NUMOF */
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 void _receive(gnrc_pktsnip_t *pkt)
{
gnrc_pktsnip_t *payload;
uint8_t *dispatch;
/* seize payload as a temporary variable */
payload = gnrc_pktbuf_start_write(pkt); /* need to duplicate since pkt->next
* might get replaced */
if (payload == NULL) {
DEBUG("6lo: can not get write access on received packet\n");
#if defined(DEVELHELP) && ENABLE_DEBUG
gnrc_pktbuf_stats();
#endif
gnrc_pktbuf_release(pkt);
return;
}
pkt = payload; /* reset pkt from temporary variable */
payload = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_SIXLOWPAN);
if ((payload == NULL) || (payload->size < 1)) {
DEBUG("6lo: Received packet has no 6LoWPAN payload\n");
gnrc_pktbuf_release(pkt);
return;
}
dispatch = payload->data;
if (dispatch[0] == SIXLOWPAN_UNCOMP) {
gnrc_pktsnip_t *sixlowpan;
DEBUG("6lo: received uncompressed IPv6 packet\n");
payload = gnrc_pktbuf_start_write(payload);
if (payload == NULL) {
DEBUG("6lo: can not get write access on received packet\n");
#if defined(DEVELHELP) && ENABLE_DEBUG
gnrc_pktbuf_stats();
#endif
gnrc_pktbuf_release(pkt);
return;
}
/* packet is uncompressed: just mark and remove the dispatch */
sixlowpan = gnrc_pktbuf_mark(payload, sizeof(uint8_t), GNRC_NETTYPE_SIXLOWPAN);
if (sixlowpan == NULL) {
DEBUG("6lo: can not mark 6LoWPAN dispatch\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = gnrc_pktbuf_remove_snip(pkt, sixlowpan);
payload->type = GNRC_NETTYPE_IPV6;
}
#ifdef MODULE_GNRC_SIXLOWPAN_FRAG
else if (sixlowpan_frag_is((sixlowpan_frag_t *)dispatch)) {
DEBUG("6lo: received 6LoWPAN fragment\n");
gnrc_sixlowpan_frag_handle_pkt(pkt);
return;
}
#endif
#ifdef MODULE_GNRC_SIXLOWPAN_IPHC
else if (sixlowpan_iphc_is(dispatch)) {
size_t dispatch_size, nh_len;
gnrc_pktsnip_t *sixlowpan;
gnrc_pktsnip_t *dec_hdr = gnrc_pktbuf_add(NULL, NULL, sizeof(ipv6_hdr_t),
GNRC_NETTYPE_IPV6);
if ((dec_hdr == NULL) ||
(dispatch_size = gnrc_sixlowpan_iphc_decode(&dec_hdr, pkt, 0, 0,
&nh_len)) == 0) {
DEBUG("6lo: error on IPHC decoding\n");
if (dec_hdr != NULL) {
gnrc_pktbuf_release(dec_hdr);
}
gnrc_pktbuf_release(pkt);
return;
}
sixlowpan = gnrc_pktbuf_mark(pkt, dispatch_size, GNRC_NETTYPE_SIXLOWPAN);
if (sixlowpan == NULL) {
DEBUG("6lo: error on marking IPHC dispatch\n");
gnrc_pktbuf_release(dec_hdr);
gnrc_pktbuf_release(pkt);
return;
}
/* Remove IPHC dispatches */
/* Insert decoded header instead */
pkt = gnrc_pktbuf_replace_snip(pkt, sixlowpan, dec_hdr);
payload->type = GNRC_NETTYPE_UNDEF;
}
#endif
else {
DEBUG("6lo: dispatch %02" PRIx8 " ... is not supported\n",
dispatch[0]);
gnrc_pktbuf_release(pkt);
return;
}
if (!gnrc_netapi_dispatch_receive(GNRC_NETTYPE_IPV6, GNRC_NETREG_DEMUX_CTX_ALL, pkt)) {
DEBUG("6lo: No receivers for this packet found\n");
gnrc_pktbuf_release(pkt);
}
}
static void _send(gnrc_pktsnip_t *pkt)
{
gnrc_netif_hdr_t *hdr;
gnrc_pktsnip_t *pkt2;
gnrc_netif_t *iface;
/* datagram_size: pure IPv6 packet without 6LoWPAN dispatches or compression */
size_t datagram_size;
if ((pkt == NULL) || (pkt->size < sizeof(gnrc_netif_hdr_t))) {
DEBUG("6lo: Sending packet has no netif header\n");
gnrc_pktbuf_release(pkt);
return;
}
if ((pkt->next == NULL) || (pkt->next->type != GNRC_NETTYPE_IPV6)) {
DEBUG("6lo: Sending packet has no IPv6 header\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt2 = gnrc_pktbuf_start_write(pkt);
if (pkt2 == NULL) {
DEBUG("6lo: no space left in packet buffer\n");
gnrc_pktbuf_release(pkt);
return;
}
hdr = pkt2->data;
iface = gnrc_netif_get_by_pid(hdr->if_pid);
datagram_size = gnrc_pkt_len(pkt2->next);
if (iface == NULL) {
DEBUG("6lo: Can not get 6LoWPAN specific interface information.\n");
gnrc_pktbuf_release(pkt);
return;
}
#ifdef MODULE_GNRC_SIXLOWPAN_IPHC
if (iface->flags & GNRC_NETIF_FLAGS_6LO_HC) {
if (!gnrc_sixlowpan_iphc_encode(pkt2)) {
DEBUG("6lo: error on IPHC encoding\n");
gnrc_pktbuf_release(pkt2);
return;
}
/* IPHC dispatch does not count on dispatch length since it _shortens_
* the datagram */
}
else {
if (!_add_uncompr_disp(pkt2)) {
/* adding uncompressed dispatch failed */
DEBUG("6lo: no space left in packet buffer\n");
gnrc_pktbuf_release(pkt2);
return;
}
}
#else
/* suppress clang-analyzer report about iface being not read */
(void) iface;
if (!_add_uncompr_disp(pkt2)) {
/* adding uncompressed dispatch failed */
DEBUG("6lo: no space left in packet buffer\n");
gnrc_pktbuf_release(pkt2);
return;
}
#endif
DEBUG("6lo: iface->sixlo.max_frag_size = %" PRIu16 " for interface %"
PRIkernel_pid "\n", iface->sixlo.max_frag_size, hdr->if_pid);
/* IP should not send anything here if it is not a 6LoWPAN interface,
* so we don't need to check for NULL pointers.
* Note, that datagram_size cannot be used here, because the header size
* might be changed by IPHC. */
if (gnrc_pkt_len(pkt2->next) <= iface->sixlo.max_frag_size) {
DEBUG("6lo: Send SND command for %p to %" PRIu16 "\n",
(void *)pkt2, hdr->if_pid);
if (gnrc_netapi_send(hdr->if_pid, pkt2) < 1) {
DEBUG("6lo: unable to send %p over %" PRIu16 "\n", (void *)pkt, hdr->if_pid);
gnrc_pktbuf_release(pkt2);
}
return;
}
#ifdef MODULE_GNRC_SIXLOWPAN_FRAG
else if (fragment_msg.pkt != NULL) {
DEBUG("6lo: Fragmentation already ongoing. Dropping packet\n");
gnrc_pktbuf_release(pkt2);
return;
}
else if (datagram_size <= SIXLOWPAN_FRAG_MAX_LEN) {
DEBUG("6lo: Send fragmented (%u > %" PRIu16 ")\n",
(unsigned int)datagram_size, iface->max_frag_size);
msg_t msg;
fragment_msg.pid = hdr->if_pid;
fragment_msg.pkt = pkt2;
fragment_msg.datagram_size = datagram_size;
/* Sending the first fragment has an offset==0 */
fragment_msg.offset = 0;
/* set the outgoing message's fields */
msg.type = GNRC_SIXLOWPAN_MSG_FRAG_SND;
msg.content.ptr = &fragment_msg;
/* send message to self */
msg_send_to_self(&msg);
}
else {
DEBUG("6lo: packet too big (%u > %" PRIu16 ")\n",
(unsigned int)datagram_size, (uint16_t)SIXLOWPAN_FRAG_MAX_LEN);
gnrc_pktbuf_release(pkt2);
}
#else
(void) datagram_size;
DEBUG("6lo: packet too big (%u > %" PRIu16 ")\n",
(unsigned int)datagram_size, iface->max_frag_size);
gnrc_pktbuf_release(pkt2);
#endif
}