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contiki/core/net/uip-nd6-io.c
adamdunkels 0db31db624 Moved declarations to the start of each function
2010-02-02 21:09:06 +00:00

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/**
* \addtogroup uip6
* @{
*/
/**
* \file
* Neighbor discovery Input-Output (RFC 4861)
* \author Julien Abeille <jabeille@cisco.com>
* \author Mathilde Durvy <mdurvy@cisco.com>
*/
/*
* 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 <string.h>
#include "net/uip-icmp6.h"
#include "net/uip-nd6.h"
#include "net/uip-netif.h"
/*------------------------------------------------------------------*/
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#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 <stdio.h>
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)
{
u8_t flags;
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);
#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)
{
/*
* 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));
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);
#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;
}
/** @} */
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