/** * \addtogroup uip6 * @{ */ /** * \file * Neighbor discovery Input-Output (RFC 4861) * \author Julien Abeille * \author Mathilde Durvy */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 2006, Swedish Institute of Computer Science. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #include #include "net/uip-icmp6.h" #include "net/uip-nd6.h" #include "net/uip-netif.h" /*------------------------------------------------------------------*/ #define DEBUG 0 #if DEBUG #include #define PRINTF(...) printf(__VA_ARGS__) #define PRINT6ADDR(addr) PRINTF(" %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x ", ((u8_t *)addr)[0], ((u8_t *)addr)[1], ((u8_t *)addr)[2], ((u8_t *)addr)[3], ((u8_t *)addr)[4], ((u8_t *)addr)[5], ((u8_t *)addr)[6], ((u8_t *)addr)[7], ((u8_t *)addr)[8], ((u8_t *)addr)[9], ((u8_t *)addr)[10], ((u8_t *)addr)[11], ((u8_t *)addr)[12], ((u8_t *)addr)[13], ((u8_t *)addr)[14], ((u8_t *)addr)[15]) #define PRINTLLADDR(lladdr) PRINTF(" %02x:%02x:%02x:%02x:%02x:%02x ",lladdr->addr[0], lladdr->addr[1], lladdr->addr[2], lladdr->addr[3],lladdr->addr[4], lladdr->addr[5]) #else #define PRINTF(...) #define PRINT6ADDR(addr) #define PRINTLLADDR(lladdr) #endif #if UIP_LOGGING #include void uip_log(char *msg); #define UIP_LOG(m) uip_log(m) #else #define UIP_LOG(m) #endif /* UIP_LOGGING == 1 */ /*------------------------------------------------------------------*/ /** @{ */ /** \name Pointers to the header structures. * All pointers except UIP_IP_BUF depend on uip_ext_len, which at * packet reception, is the total length of the extension headers. * * The pointer to ND6 options header also depends on nd6_opt_offset, * which we set in each function. * * Care should be taken when manipulating these buffers about the * value of these length variables */ #define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN]) /**< Pointer to IP header */ #define UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[uip_l2_l3_hdr_len]) /**< Pointer to ICMP header*/ /**@{ Pointers to messages just after icmp header */ #define UIP_ND6_RS_BUF ((struct uip_nd6_rs *)&uip_buf[uip_l2_l3_icmp_hdr_len]) #define UIP_ND6_RA_BUF ((struct uip_nd6_ra *)&uip_buf[uip_l2_l3_icmp_hdr_len]) #define UIP_ND6_NS_BUF ((struct uip_nd6_ns *)&uip_buf[uip_l2_l3_icmp_hdr_len]) #define UIP_ND6_NA_BUF ((struct uip_nd6_na *)&uip_buf[uip_l2_l3_icmp_hdr_len]) #define UIP_ICMP6_ERROR_BUF ((struct uip_icmp6_error *)&uip_buf[uip_l2_l3_icmp_hdr_len]) /** @} */ /** Pointer to ND option */ #define UIP_ND6_OPT_HDR_BUF ((struct uip_nd6_opt_hdr *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset]) /** @} */ /** \brief Offset from the end of the icmpv6 header to the option in uip_buf*/ static u8_t nd6_opt_offset; /** \brief Pointer to llao option in uip_buf */ static struct uip_nd6_opt_llao *nd6_opt_llao; /** \brief Pointer to mtu option in uip_buf */ static struct uip_nd6_opt_mtu *nd6_opt_mtu; /** \brief Pointer to prefix information option in uip_buf */ static struct uip_nd6_opt_prefix_info *nd6_opt_prefix_info[UIP_CONF_ND6_MAX_PREFIXES]; /** \brief Pointer to a neighbor cache entry*/ static struct uip_nd6_neighbor *neighbor; /** \brief Pointer to a prefix list entry */ static struct uip_nd6_prefix *prefix; /** \brief Pointer to a router list entry */ static struct uip_nd6_defrouter *router; /** \brief Pointer to an interface address */ static struct uip_netif_addr *ifaddr; /** \brief Index used in loops */ static u8_t i; /*------------------------------------------------------------------*/ void uip_nd6_io_ns_input(void) { PRINTF("Received NS from"); PRINT6ADDR(&UIP_IP_BUF->srcipaddr); PRINTF("to"); PRINT6ADDR(&UIP_IP_BUF->destipaddr); PRINTF("with target address"); PRINT6ADDR((uip_ipaddr_t *)(&UIP_ND6_NS_BUF->tgtipaddr)); PRINTF("\n"); UIP_STAT(++uip_stat.nd6.recv); u8_t flags; #if UIP_CONF_IPV6_CHECKS if((UIP_IP_BUF->ttl != UIP_ND6_HOP_LIMIT) || (uip_is_addr_mcast(&UIP_ND6_NS_BUF->tgtipaddr)) || (UIP_ICMP_BUF->icode != 0)) { goto badpkt; } #endif /* UIP_CONF_IPV6_CHECKS */ /* Options reading: we handle only SLLAO for now */ nd6_opt_llao = NULL; nd6_opt_offset = UIP_ND6_NS_LEN; while(uip_l3_icmp_hdr_len + nd6_opt_offset < uip_len) { #if UIP_CONF_IPV6_CHECKS if(UIP_ND6_OPT_HDR_BUF->len == 0) { goto badpkt; } #endif /* UIP_CONF_IPV6_CHECKS */ switch(UIP_ND6_OPT_HDR_BUF->type) { case UIP_ND6_OPT_SLLAO: nd6_opt_llao = (struct uip_nd6_opt_llao *)UIP_ND6_OPT_HDR_BUF; break; default: UIP_LOG("ND option not supported in NS"); break; } nd6_opt_offset += (UIP_ND6_OPT_HDR_BUF->len << 3); } /* Options processing: only SLLAO */ if(nd6_opt_llao != NULL) { #if UIP_CONF_IPV6_CHECKS /* There must be NO option in a DAD NS */ if(uip_is_addr_unspecified(&UIP_IP_BUF->srcipaddr)) { goto badpkt; } else { #endif /*UIP_CONF_IPV6_CHECKS*/ neighbor = uip_nd6_nbrcache_lookup(&UIP_IP_BUF->srcipaddr); if(neighbor == NULL) { /* we need to add the neighbor*/ uip_nd6_nbrcache_add(&UIP_IP_BUF->srcipaddr, &nd6_opt_llao->addr, 0, STALE); } else { /* If LL address changed, set neighbor state to stale */ if(memcmp(&nd6_opt_llao->addr, &neighbor->lladdr, UIP_LLADDR_LEN) != 0) { memcpy(&neighbor->lladdr, &nd6_opt_llao->addr, UIP_LLADDR_LEN); neighbor->state = STALE; } else { /* If neighbor state is INCOMPLETE, set to STALE */ if(neighbor->state == INCOMPLETE) { neighbor->state = STALE; } } } #if UIP_CONF_IPV6_CHECKS } #endif /*UIP_CONF_IPV6_CHECKS*/ } /* * Rest of NS processing: Depends on the purpose of the NS: NUD or DAD or * Address Resolution */ /** \note we use ifaddr to remember the target address */ ifaddr = uip_netif_addr_lookup(&UIP_ND6_NS_BUF->tgtipaddr, 128, 0); if(ifaddr != NULL) { if(uip_is_addr_unspecified(&UIP_IP_BUF->srcipaddr)){ /* DAD CASE */ #if UIP_CONF_IPV6_CHECKS /* Dst address must be solicited node mcast address */ if(!uip_netif_is_addr_my_solicited(&UIP_IP_BUF->destipaddr)){ goto badpkt; } #endif /* UIP_CONF_IPV6_CHECKS */ /* * If my address is not tentative, then send a NA to all nodes with * TLLAO flags are: override = yes. */ if(ifaddr->state!=TENTATIVE) { /* * we need to send a NA, we set the src, dest, flags. tgt remains the * same and the rest is done at "create_na" */ uip_create_linklocal_allnodes_mcast(&UIP_IP_BUF->destipaddr); uip_netif_select_src(&UIP_IP_BUF->srcipaddr, &UIP_IP_BUF->destipaddr); flags = UIP_ND6_NA_FLAG_OVERRIDE; goto create_na; } else { /** \todo if I sent a NS before him, I win */ uip_netif_dad_failed(&UIP_ND6_NS_BUF->tgtipaddr); goto discard; } } #if UIP_CONF_IPV6_CHECKS /* Duplicate check */ if(uip_netif_is_addr_my_unicast(&UIP_IP_BUF->srcipaddr)) { /** * \NOTE do we do something here? we both are using the same address. * If we are doing dad, we could cancel it, though we should receive a * NA in response of DAD NS we sent, hence DAD will fail anyway. If we * were not doing DAD, it means there is a duplicate in the network! */ goto badpkt; } #endif /*UIP_CONF_IPV6_CHECKS*/ /* Address resolution case */ if(uip_netif_is_addr_my_solicited(&UIP_IP_BUF->destipaddr)){ /* * we need to send a NA, we set the src, dest, flags. The rest is * set at the "create_na" label. */ uip_ipaddr_copy(&UIP_IP_BUF->destipaddr, &UIP_IP_BUF->srcipaddr); uip_ipaddr_copy(&UIP_IP_BUF->srcipaddr, &UIP_ND6_NS_BUF->tgtipaddr); flags = UIP_ND6_NA_FLAG_SOLICITED | UIP_ND6_NA_FLAG_OVERRIDE; goto create_na; } /* * NUD CASE. at this point the packet must be for us! we check this, * and at the same time if target == dest */ if(uip_netif_addr_lookup(&UIP_IP_BUF->destipaddr, 128, 0) == ifaddr){ /* * we need to send a NA, we set the src, dest, flags. The rest is set * at the "create_na" label. */ uip_ipaddr_copy(&UIP_IP_BUF->destipaddr, &UIP_IP_BUF->srcipaddr); uip_ipaddr_copy(&UIP_IP_BUF->srcipaddr, &UIP_ND6_NS_BUF->tgtipaddr); flags = UIP_ND6_NA_FLAG_SOLICITED | UIP_ND6_NA_FLAG_OVERRIDE; goto create_na; } else { #if UIP_CONF_IPV6_CHECKS goto badpkt; #endif /* UIP_CONF_IPV6_CHECKS */ } } else { goto discard; } create_na: /* * Fill the part of the NA which is common to all NAs. If the NS contained * extension headers, we must set the target address properly */ uip_ext_len = 0; /* IP header */ UIP_IP_BUF->vtc = 0x60; UIP_IP_BUF->tcflow = 0; UIP_IP_BUF->flow = 0; UIP_IP_BUF->len[0] = 0; /* length will not be more than 255 */ UIP_IP_BUF->len[1] = UIP_ICMPH_LEN + UIP_ND6_NA_LEN + UIP_ND6_OPT_LLAO_LEN; UIP_IP_BUF->proto = UIP_PROTO_ICMP6; UIP_IP_BUF->ttl = UIP_ND6_HOP_LIMIT; /* ICMP header */ UIP_ICMP_BUF->type = ICMP6_NA; UIP_ICMP_BUF->icode = 0; /* NA static part */ UIP_ND6_NA_BUF->flagsreserved = flags; memcpy(&UIP_ND6_NA_BUF->tgtipaddr, &ifaddr->ipaddr, sizeof(uip_ipaddr_t)); /* NA option: TLLAO. note that length field is in unit of 8 bytes */ uip_len = UIP_IPH_LEN + UIP_ICMPH_LEN + UIP_ND6_NA_LEN + UIP_ND6_OPT_LLAO_LEN; nd6_opt_llao = (struct uip_nd6_opt_llao *)&uip_buf[uip_l2_l3_icmp_hdr_len + UIP_ND6_NA_LEN]; nd6_opt_llao->type = UIP_ND6_OPT_TLLAO; nd6_opt_llao->len = UIP_ND6_OPT_LLAO_LEN >> 3; memcpy(&(nd6_opt_llao->addr), &uip_lladdr, UIP_LLADDR_LEN); /* padding if needed */ memset((void *)(&nd6_opt_llao->addr) + UIP_LLADDR_LEN, 0, UIP_ND6_OPT_LLAO_LEN - 2 - UIP_LLADDR_LEN); /*ICMP checksum*/ UIP_ICMP_BUF->icmpchksum = 0; UIP_ICMP_BUF->icmpchksum = ~uip_icmp6chksum(); UIP_STAT(++uip_stat.nd6.sent); PRINTF("Sending NA to"); PRINT6ADDR(&UIP_IP_BUF->destipaddr); PRINTF("from"); PRINT6ADDR(&UIP_IP_BUF->srcipaddr); PRINTF("with target address"); PRINT6ADDR(&UIP_ND6_NA_BUF->tgtipaddr); PRINTF("\n"); return; #if UIP_CONF_IPV6_CHECKS badpkt: UIP_STAT(++uip_stat.nd6.drop); UIP_LOG("NS received is bad"); #endif /* UIP_CONF_IPV6_CHECKS */ discard: uip_len = 0; return; } /*------------------------------------------------------------------*/ void uip_nd6_io_ns_output(uip_ipaddr_t *src, uip_ipaddr_t *dest, uip_ipaddr_t *tgt) { /* IP header fields */ uip_ext_len = 0; UIP_IP_BUF->vtc = 0x60; UIP_IP_BUF->tcflow = 0; UIP_IP_BUF->flow = 0; UIP_IP_BUF->proto = UIP_PROTO_ICMP6; UIP_IP_BUF->ttl = UIP_ND6_HOP_LIMIT; /* * The caller must put a valid tgt address. * For dest, if the caller is doing DAD or Address resolution, he sets * dest to NULL and we forge dest as the sollicited node mcast address * for tgt. * If the caller is sending the NS for NUD, dest is unicast and the caller * specifies it in the arguments */ if(dest == NULL) { uip_create_solicited_node(tgt, &UIP_IP_BUF->destipaddr); } else { uip_ipaddr_copy(&UIP_IP_BUF->destipaddr, dest); } UIP_ICMP_BUF->type = ICMP6_NS; UIP_ICMP_BUF->icode = 0; UIP_ND6_NS_BUF->reserved = 0; /* Copy the tgt address */ uip_ipaddr_copy((uip_ipaddr_t *)&UIP_ND6_NS_BUF->tgtipaddr, tgt); UIP_IP_BUF->len[0] = 0; /* length will not be more than 255 */ /* * check if we add a SLLAO option: for DAD, MUST NOT, for NUD, MAY * (here yes), for Address resolution , MUST * i.e. if and only if tgt is our address (in this case it is DAD), we do * not add it */ if(!(uip_netif_is_addr_my_unicast(tgt))) { if(src != NULL) { uip_ipaddr_copy(&UIP_IP_BUF->srcipaddr, src); } else { uip_netif_select_src(&UIP_IP_BUF->srcipaddr, &UIP_IP_BUF->destipaddr); } UIP_IP_BUF->len[1] = UIP_ICMPH_LEN + UIP_ND6_NS_LEN + UIP_ND6_OPT_LLAO_LEN; uip_len = UIP_IPH_LEN + UIP_ICMPH_LEN + UIP_ND6_NS_LEN + UIP_ND6_OPT_LLAO_LEN; nd6_opt_llao = (struct uip_nd6_opt_llao *)&uip_buf[uip_l2_l3_icmp_hdr_len + UIP_ND6_NS_LEN]; nd6_opt_llao->type = UIP_ND6_OPT_SLLAO; /* type of the option */ /* * length of the option: 2 bytes for type, length, plus the length of * the L2 address. It must be in units of 8 bytes */ nd6_opt_llao->len = UIP_ND6_OPT_LLAO_LEN >> 3; memcpy(&nd6_opt_llao->addr, &uip_lladdr, UIP_LLADDR_LEN); /* padding if needed */ memset((void *)(&nd6_opt_llao->addr) + UIP_LLADDR_LEN, 0, UIP_ND6_OPT_LLAO_LEN - 2 - UIP_LLADDR_LEN); } else { uip_create_unspecified(&UIP_IP_BUF->srcipaddr); UIP_IP_BUF->len[1] = UIP_ICMPH_LEN + UIP_ND6_NS_LEN; uip_len = UIP_IPH_LEN + UIP_ICMPH_LEN + UIP_ND6_NS_LEN; } UIP_ICMP_BUF->icmpchksum = 0; UIP_ICMP_BUF->icmpchksum = ~uip_icmp6chksum(); UIP_STAT(++uip_stat.nd6.sent); PRINTF("Sending NS to"); PRINT6ADDR(&UIP_IP_BUF->destipaddr); PRINTF("from"); PRINT6ADDR(&UIP_IP_BUF->srcipaddr); PRINTF("with target address"); PRINT6ADDR(tgt); PRINTF("\n"); return; } /*------------------------------------------------------------------*/ void uip_nd6_io_na_input(void) { PRINTF("Received NA from"); PRINT6ADDR(&UIP_IP_BUF->srcipaddr); PRINTF("to"); PRINT6ADDR(&UIP_IP_BUF->destipaddr); PRINTF("with target address"); PRINT6ADDR((uip_ipaddr_t *)(&UIP_ND6_NA_BUF->tgtipaddr)); PRINTF("\n"); UIP_STAT(++uip_stat.nd6.recv); /* * booleans. the three last one are not 0 or 1 but 0 or 0x80, 0x40, 0x20 * but it works. Be careful though, do not use tests such as is_router == 1 */ u8_t is_llchange = 0; u8_t is_router = ((UIP_ND6_NA_BUF->flagsreserved & UIP_ND6_NA_FLAG_ROUTER)); u8_t is_solicited = ((UIP_ND6_NA_BUF->flagsreserved & UIP_ND6_NA_FLAG_SOLICITED)); u8_t is_override = ((UIP_ND6_NA_BUF->flagsreserved & UIP_ND6_NA_FLAG_OVERRIDE)); #if UIP_CONF_IPV6_CHECKS /* * Check hop limit / icmp code * target address must not be multicast * if the NA is solicited, dest must not be multicast */ if((UIP_IP_BUF->ttl != UIP_ND6_HOP_LIMIT) || (UIP_ICMP_BUF->icode != 0) || (uip_is_addr_mcast(&UIP_ND6_NA_BUF->tgtipaddr)) || (is_solicited && uip_is_addr_mcast(&UIP_IP_BUF->destipaddr))) { goto badpkt; } #endif /*UIP_CONF_IPV6_CHECKS*/ /* Options reading: we can handle TLLAO, and must ignore othehrs */ nd6_opt_offset = UIP_ND6_NA_LEN; nd6_opt_llao = NULL; while(uip_l3_icmp_hdr_len + nd6_opt_offset < uip_len) { #if UIP_CONF_IPV6_CHECKS if(UIP_ND6_OPT_HDR_BUF->len == 0) { goto badpkt; } #endif /*UIP_CONF_IPV6_CHECKS*/ switch(UIP_ND6_OPT_HDR_BUF->type) { case UIP_ND6_OPT_TLLAO: nd6_opt_llao = (struct uip_nd6_opt_llao *)UIP_ND6_OPT_HDR_BUF; break; default: UIP_LOG("ND option not supported in NA"); break; } nd6_opt_offset += (UIP_ND6_OPT_HDR_BUF->len << 3); } ifaddr = uip_netif_addr_lookup(&UIP_ND6_NA_BUF->tgtipaddr, 128, 0); /* Message processing, including TLLAO if any */ if(ifaddr != NULL) { if(ifaddr->state == TENTATIVE) { /*It means DAD failed*/ uip_netif_dad_failed(&UIP_ND6_NA_BUF->tgtipaddr); } goto discard; } else { neighbor = uip_nd6_nbrcache_lookup(&UIP_ND6_NA_BUF->tgtipaddr); /* if the neighbor entry does not exist, silently discard */ if(neighbor == NULL) { goto discard; } if(nd6_opt_llao != 0) { is_llchange = memcmp((void *)&nd6_opt_llao->addr, (void *)(&neighbor->lladdr), UIP_LLADDR_LEN); } if(neighbor->state == INCOMPLETE){ if(nd6_opt_llao == 0) { goto discard; } memcpy(&neighbor->lladdr, &nd6_opt_llao->addr, UIP_LLADDR_LEN); if(is_solicited) { neighbor->state = REACHABLE; /* reachable time is stored in ms*/ stimer_set(&(neighbor->reachable), uip_netif_physical_if.reachable_time / 1000); } else { neighbor->state = STALE; } neighbor->isrouter = is_router; } else { if(!is_override && is_llchange) { if(neighbor->state == REACHABLE) { neighbor->state = STALE; } goto discard; } else { if(is_override || (!is_override && nd6_opt_llao != 0 && !is_llchange) || nd6_opt_llao == 0) { /* update LL address if any */ if(nd6_opt_llao != 0) { memcpy(&neighbor->lladdr, &nd6_opt_llao->addr, UIP_LLADDR_LEN); } /* * if the NA was solicited, change the state of the neighbor to * reachabe. Otherwise and if the neighbor LL changed, set the * state to STALE */ if(is_solicited) { neighbor->state = REACHABLE; /* reachable time is stored in ms*/ stimer_set(&(neighbor->reachable), uip_netif_physical_if.reachable_time / 1000); } else { if(nd6_opt_llao != 0 && is_llchange) { neighbor->state = STALE; } } } } if(neighbor->isrouter && !is_router){ /* the neighbor stopped being a router, we remove it from the list */ router = uip_nd6_defrouter_lookup(neighbor); if(router != NULL){ uip_nd6_defrouter_rm(router); } } neighbor->isrouter = is_router; } } #if UIP_CONF_IPV6_QUEUE_PKT /* The neighbor is now reachable, check if we had buffered a pkt for it */ if(neighbor->queue_buf_len != 0) { uip_len = neighbor->queue_buf_len; memcpy(UIP_IP_BUF, neighbor->queue_buf, uip_len); neighbor->queue_buf_len = 0; return; } #endif /*UIP_CONF_IPV6_QUEUE_PKT*/ uip_len = 0; return; #if UIP_CONF_IPV6_CHECKS badpkt: UIP_STAT(++uip_stat.nd6.drop); UIP_LOG("NA received is bad"); #endif /* UIP_CONF_IPV6_CHECKS */ discard: uip_len = 0; return; } /*---------------------------------------------------------------------------*/ void uip_nd6_io_rs_output(void) { UIP_IP_BUF->vtc = 0x60; UIP_IP_BUF->tcflow = 0; UIP_IP_BUF->flow = 0; UIP_IP_BUF->proto = UIP_PROTO_ICMP6; UIP_IP_BUF->ttl = UIP_ND6_HOP_LIMIT; uip_create_linklocal_allrouters_mcast(&UIP_IP_BUF->destipaddr); uip_netif_select_src(&UIP_IP_BUF->srcipaddr, &UIP_IP_BUF->destipaddr); UIP_ICMP_BUF->type = ICMP6_RS; UIP_ICMP_BUF->icode = 0; UIP_ND6_RS_BUF->reserved = 0; UIP_IP_BUF->len[0] = 0; /* length will not be more than 255 */ /* we add the SLLAO option only if src is not unspecified */ if(uip_is_addr_unspecified(&UIP_IP_BUF->srcipaddr)) { UIP_IP_BUF->len[1] = UIP_ICMPH_LEN + UIP_ND6_RS_LEN; uip_len = uip_l3_icmp_hdr_len + UIP_ND6_RS_LEN; } else { uip_len = uip_l3_icmp_hdr_len + UIP_ND6_RS_LEN + UIP_ND6_OPT_LLAO_LEN; UIP_IP_BUF->len[1] = UIP_ICMPH_LEN + UIP_ND6_RS_LEN + UIP_ND6_OPT_LLAO_LEN; nd6_opt_llao = (struct uip_nd6_opt_llao *)&uip_buf[uip_l2_l3_icmp_hdr_len + UIP_ND6_RS_LEN]; nd6_opt_llao->type = UIP_ND6_OPT_SLLAO; /* type of the option */ nd6_opt_llao->len = UIP_ND6_OPT_LLAO_LEN >> 3; /* length of the option in units of 8 bytes */ memcpy(&nd6_opt_llao->addr, &uip_lladdr, UIP_LLADDR_LEN); /* padding if needed */ memset((void *)(&nd6_opt_llao->addr) + UIP_LLADDR_LEN, 0, UIP_ND6_OPT_LLAO_LEN - 2 - UIP_LLADDR_LEN); } UIP_ICMP_BUF->icmpchksum = 0; UIP_ICMP_BUF->icmpchksum = ~uip_icmp6chksum(); UIP_STAT(++uip_stat.nd6.sent); PRINTF("Sendin RS to"); PRINT6ADDR(&UIP_IP_BUF->destipaddr); PRINTF("from"); PRINT6ADDR(&UIP_IP_BUF->srcipaddr); PRINTF("\n"); return; } /*---------------------------------------------------------------------------*/ void uip_nd6_io_ra_input(void) { PRINTF("Received RA from"); PRINT6ADDR(&UIP_IP_BUF->srcipaddr); PRINTF("to"); PRINT6ADDR(&UIP_IP_BUF->destipaddr); PRINTF("\n"); UIP_STAT(++uip_stat.nd6.recv); #if UIP_CONF_IPV6_CHECKS /* a few validity checks */ if((UIP_IP_BUF->ttl != UIP_ND6_HOP_LIMIT) || (!uip_is_addr_link_local(&UIP_IP_BUF->srcipaddr)) || (UIP_ICMP_BUF->icode != 0)) { goto badpkt; } #endif /*UIP_CONF_IPV6_CHECKS*/ /* * process the fields of the constant part * As per RFC 4861, for reachable time and retrans timer, a value of 0 means * unspecified by this router. * If router lifetime is 0, the router SHOULD NOT be placed in default * router list */ if(UIP_ND6_RA_BUF->cur_ttl != 0) { uip_netif_physical_if.cur_hop_limit = UIP_ND6_RA_BUF->cur_ttl; PRINTF("uip_netif_physical_if.cur_hop_limit %u\n", uip_netif_physical_if.cur_hop_limit); } /* * As per RFC4861 section 6.3.4, if reachable time field is non zero * and defers from the current base reachable time for the interface, * set base reachable time to the new value and recompute the reachable time * as a random value distributed between 0.5 and 1.5 x Base reachable time */ if(UIP_ND6_RA_BUF->reachable_time != 0) { if(uip_netif_physical_if.base_reachable_time != ntohl(UIP_ND6_RA_BUF->reachable_time)) { uip_netif_physical_if.base_reachable_time = ntohl(UIP_ND6_RA_BUF->reachable_time); uip_netif_physical_if.reachable_time = uip_netif_compute_reachable_time(); } } if(UIP_ND6_RA_BUF->retrans_timer !=0) { uip_netif_physical_if.retrans_timer = ntohl(UIP_ND6_RA_BUF->retrans_timer); } /* * Note: in our implementation, an entry in the default router list contains * does not contain the IP address of the router. The entry has a pointer * to the corresponding neighbor cache entry, where the IP address is stored */ /* Options reading: possible options are MTU, SLLAO, prefix */ nd6_opt_llao = NULL; nd6_opt_mtu = NULL; for(i = 0; i < UIP_CONF_ND6_MAX_PREFIXES; i++) { nd6_opt_prefix_info[i] = NULL; } nd6_opt_offset = UIP_ND6_RA_LEN; while(uip_l3_icmp_hdr_len + nd6_opt_offset < uip_len) { if(UIP_ND6_OPT_HDR_BUF->len == 0) { goto badpkt; } switch(UIP_ND6_OPT_HDR_BUF->type) { case UIP_ND6_OPT_SLLAO: nd6_opt_llao = (struct uip_nd6_opt_llao *)UIP_ND6_OPT_HDR_BUF; break; case UIP_ND6_OPT_MTU: nd6_opt_mtu = (struct uip_nd6_opt_mtu *)UIP_ND6_OPT_HDR_BUF; break; case UIP_ND6_OPT_PREFIX_INFO: i = 0; while((i < UIP_CONF_ND6_MAX_PREFIXES) && (nd6_opt_prefix_info[i] != NULL)) { i++; } if(i < UIP_CONF_ND6_MAX_PREFIXES) { nd6_opt_prefix_info[i] = (struct uip_nd6_opt_prefix_info *)UIP_ND6_OPT_HDR_BUF; } break; default: UIP_LOG("ND option not supported in RA"); break; } nd6_opt_offset += (UIP_ND6_OPT_HDR_BUF->len << 3); } /* Process the MTU option if any */ if(nd6_opt_mtu != NULL) { /* just set the link MTU to the value specified. Note that this option */ PRINTF("Processing MTU option in RA\n"); uip_netif_physical_if.link_mtu = ntohl(nd6_opt_mtu->mtu); } /* Prefix information options processing */ i = 0; while((i < UIP_CONF_ND6_MAX_PREFIXES - 1) && (nd6_opt_prefix_info[i] != NULL)) { PRINTF("Processing PREFIX option in RA\n"); if((ntohl((nd6_opt_prefix_info[i])->validlt) >= ntohl((nd6_opt_prefix_info[i])->preferredlt)) && (!uip_is_addr_link_local(&nd6_opt_prefix_info[i]->prefix))) { /* on-link flag related processing*/ if(((nd6_opt_prefix_info[i])->flagsreserved1 & 0x80) == 0x80) { prefix = uip_nd6_prefix_lookup(&(nd6_opt_prefix_info[i])->prefix); if(prefix == NULL) { if((nd6_opt_prefix_info[i])->validlt != 0){ if((nd6_opt_prefix_info[i])->validlt != UIP_ND6_INFINITE_LIFETIME){ prefix = uip_nd6_prefix_add(&(nd6_opt_prefix_info[i])->prefix, (nd6_opt_prefix_info[i])->preflen, ntohl((nd6_opt_prefix_info[i])->validlt)); } else { prefix = uip_nd6_prefix_add(&(nd6_opt_prefix_info[i])->prefix, (nd6_opt_prefix_info[i])->preflen, 0); } } } else { /* we update or remove an existing prefix */ switch((nd6_opt_prefix_info[i])->validlt) { case 0: uip_nd6_prefix_rm(prefix); break; case UIP_ND6_INFINITE_LIFETIME: prefix->is_infinite = 1; break; default: PRINTF("Updating timer of prefix"); PRINT6ADDR(prefix); PRINTF("new value %lu\n", ntohl((nd6_opt_prefix_info[i])->validlt)); stimer_set(&prefix->vlifetime, ntohl((nd6_opt_prefix_info[i])->validlt)); /*in case the prefix lifetime was previously infinite */ prefix->is_infinite = 0; break; } } } /* End of on-link flag related processing */ /* autonomous flag related processing*/ if((((nd6_opt_prefix_info[i])->flagsreserved1 & 0x40) == 0x40) && ((nd6_opt_prefix_info[i])->validlt != 0)){ ifaddr = uip_netif_addr_lookup(&(nd6_opt_prefix_info[i])->prefix, (nd6_opt_prefix_info[i])->preflen, AUTOCONF); if(ifaddr != NULL) { if((nd6_opt_prefix_info[i])->validlt != UIP_ND6_INFINITE_LIFETIME) { /* The processing below is defined in RFC4862 section 5.5.3 e */ if((ntohl((nd6_opt_prefix_info[i])->validlt) > 2 * 60 * 60) || (ntohl((nd6_opt_prefix_info[i])->validlt)> stimer_remaining(&ifaddr->vlifetime))) { PRINTF("Updating timer of address"); PRINT6ADDR(&ifaddr->ipaddr); PRINTF("new value %lu\n", ntohl((nd6_opt_prefix_info[i])->validlt)); stimer_set(&ifaddr->vlifetime, ntohl((nd6_opt_prefix_info[i])->validlt)); } else { stimer_set(&ifaddr->vlifetime, 2 * 60 * 60); PRINTF("Updating timer of address "); PRINT6ADDR(&ifaddr->ipaddr); PRINTF("new value %lu\n", (unsigned long)(2 * 60 * 60)); } /*in case the address lifetime was previously infinite */ ifaddr->is_infinite = 0; } else { ifaddr->is_infinite = 1; } } else { /* Autoconfigure an address*/ if((nd6_opt_prefix_info[i])->validlt != UIP_ND6_INFINITE_LIFETIME) { /* Add an address with FINITE lifetime */ uip_netif_addr_add(&(nd6_opt_prefix_info[i])->prefix, (nd6_opt_prefix_info[i])->preflen, ntohl((nd6_opt_prefix_info[i])->validlt), AUTOCONF); } else { /* Add an address with INFINITE lifetime */ uip_netif_addr_add(&(nd6_opt_prefix_info[i])->prefix, (nd6_opt_prefix_info[i])->preflen, 0, AUTOCONF); } } } /* End of autonomous flag related processing */ } i++; } /* End of Prefix Information Option processing*/ /* SLLAO option processing */ neighbor = uip_nd6_nbrcache_lookup(&UIP_IP_BUF->srcipaddr); if(nd6_opt_llao != NULL) { PRINTF("Processing SLLAO option in RA\n"); if(neighbor == NULL) { neighbor = uip_nd6_nbrcache_add(&UIP_IP_BUF->srcipaddr, &nd6_opt_llao->addr, 1, STALE); } else { if(neighbor->state == INCOMPLETE) { neighbor->state = STALE; } /* check if there was an address change. it applies to the case * where if the router ND entry was in state NO_STATE */ if(memcmp(&nd6_opt_llao->addr, &neighbor->lladdr, UIP_LLADDR_LEN) != 0) { memcpy(&neighbor->lladdr, &nd6_opt_llao->addr, UIP_LLADDR_LEN); neighbor->state = STALE; } /*in case the neighbor was not a router before */ neighbor->isrouter = 1; } } /* * As per RFC4861, section 6.3.4, and considering that in our * implementation, a router entry contains a pointer to an existing * neighbor entry: * if router lifetime != 0, if entry present in def router list * (and therefore neighbor cache), update timer, and update neighbor entry * if needed * else add entry to both router list (and neighbor cache if absent) * else delete entry in router list if it exists */ if(UIP_ND6_RA_BUF->router_lifetime != 0) { /* Add router or update timer, we need a neighbor entry for this */ if(neighbor == NULL) { neighbor = uip_nd6_nbrcache_add(&UIP_IP_BUF->srcipaddr, NULL, 1, NO_STATE); } else { /* in case the neighbor was not a router before */ neighbor->isrouter = 1; } if((router = uip_nd6_defrouter_lookup(neighbor)) == NULL) { uip_nd6_defrouter_add(neighbor, (unsigned long)(ntohs(UIP_ND6_RA_BUF->router_lifetime))); } else { stimer_set(&(router->lifetime), (unsigned long)(ntohs(UIP_ND6_RA_BUF->router_lifetime))); } } else { /* delete router entry*/ if(neighbor != NULL) { router = uip_nd6_defrouter_lookup(neighbor); if(router != NULL) { uip_nd6_defrouter_rm(router); } } } #if UIP_CONF_IPV6_QUEUE_PKT /* * If the neighbor just became reachable (e.g. it was in INCOMPLETE state * and we got a SLLAO), check if we had buffered a pkt for it */ if((neighbor != NULL) && (neighbor->queue_buf_len != 0)) { uip_len = neighbor->queue_buf_len; memcpy(UIP_IP_BUF, neighbor->queue_buf, uip_len); neighbor->queue_buf_len = 0; return; } #endif /*UIP_CONF_IPV6_QUEUE_PKT*/ uip_len = 0; return; badpkt: UIP_STAT(++uip_stat.nd6.drop); UIP_LOG("RA received is bad"); uip_len = 0; return; } /** @} */