/* * Copyright (C) 2015 Martine Lenders * * 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 #include #include #include #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); /* 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; #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 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_NETSTATS_IPV6 if_entry->stats.tx_success++; if_entry->stats.tx_bytes += gnrc_pkt_len(pkt->next); #endif #ifdef MODULE_GNRC_SIXLOWPAN if (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\n"); gnrc_pktbuf_release(pkt); } return; } #endif if (gnrc_netapi_send(iface, 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 = 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 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 iface 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->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 to front of the pkt list */ LL_PREPEND(pkt, netif); return 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) { 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", iface); /* and send to interface */ #ifdef MODULE_NETSTATS_IPV6 gnrc_ipv6_netif_get_stats(iface)->tx_unicast_count++; #endif _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; #ifdef MODULE_NETSTATS_IPV6 gnrc_ipv6_netif_get_stats(iface)->tx_mcast_count++; #endif /* 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 /* interface not given: 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 */ 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; } } if ((ipv6 = _create_netif_hdr(NULL, 0, ipv6)) == NULL) { return; } _send_multicast_over_iface(ifs[i], ipv6); } } else { 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) { iface = ifs[0]; /* allocate interface header */ if ((pkt = _create_netif_hdr(NULL, 0, pkt)) == NULL) { return; } } 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 _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 _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); } /** @} */