/************************************************************************
* NAME: fnet_icmp6_error
*
* DESCRIPTION: Sends ICMPv6 error message.
*************************************************************************/
void fnet_icmp6_error( fnet_netif_t *netif, unsigned char type, unsigned char code, unsigned long param, fnet_netbuf_t *origin_nb )
{
fnet_ip6_header_t *ip6_header;
fnet_icmp6_err_header_t *icmp6_err_header;
fnet_ip6_addr_t *src_ip;
const fnet_ip6_addr_t *dest_ip;
fnet_netbuf_t *nb_header;
if(origin_nb)
{
/* Limit to FNET_IP6_DEFAULT_MTU. */
if(origin_nb->total_length > (FNET_IP6_DEFAULT_MTU - (sizeof(fnet_icmp6_err_header_t) + sizeof(fnet_ip6_header_t)) ))
fnet_netbuf_trim(&origin_nb, (int)(FNET_IP6_DEFAULT_MTU - (sizeof(fnet_icmp6_err_header_t) + sizeof(fnet_ip6_header_t)) - origin_nb->total_length));
ip6_header = origin_nb->data_ptr;
src_ip = &ip6_header->source_addr;
dest_ip = &ip6_header->destination_addr;
/*******************************************************************
* RFC 4443:
* (e) An ICMPv6 error message MUST NOT be originated as a result of
* receiving the following:
*******************************************************************/
/* (e.1) An ICMPv6 error message. */
/* (e.2) An ICMPv6 REDIRECT message [IPv6-DISC].*/
if (ip6_header->next_header == FNET_IP_PROTOCOL_ICMP6) /* TBD Extension header case.*/
{
/* Make sure the packet has at least a 'TYPE' field */
if (ip6_header->length == 0)
{
goto FREE_NB;
}
icmp6_err_header = (fnet_icmp6_err_header_t *)((unsigned char *)ip6_header + sizeof(fnet_ip6_header_t));
if (FNET_ICMP6_TYPE_IS_ERROR(icmp6_err_header->icmp6_header.type) || (icmp6_err_header->icmp6_header.type == FNET_ICMP6_TYPE_REDIRECT ) )
{
goto FREE_NB;
}
}
/*
* (e.3) A packet destined to an IPv6 multicast address. (There are
* two exceptions to this rule: (1) the Packet Too Big Message
* (Section 3.2) to allow Path MTU discovery to work for IPv6
* multicast, and (2) the Parameter Problem Message, Code 2
* (Section 3.4) reporting an unrecognized IPv6 option (see
* Section 4.2 of [IPv6]) that has the Option Type highestorder
* two bits set to 10).
* (e.4) A packet sent as a link-layer multicast (the exceptions
* from e.3 apply to this case, too).
*/
if(FNET_IP6_ADDR_IS_MULTICAST(dest_ip)
&& !( (type == FNET_ICMP6_TYPE_PACKET_TOOBIG)
|| ((type == FNET_ICMP6_TYPE_PARAM_PROB) && (code == FNET_ICMP6_CODE_PP_OPTION))) )
{
goto FREE_NB;
}
else
{
if(FNET_IP6_ADDR_IS_MULTICAST(dest_ip))
{
/* We may not use multicast address as source. Get real source address. */
dest_ip = fnet_ip6_select_src_addr(netif, src_ip /*dest*/);
}
}
/*
* (e.5) A packet sent as a link-layer broadcast (the exceptions
* from e.3 apply to this case, too). TBD
*/
/*
* (e.6) A packet whose source address does not uniquely identify a
* single node -- e.g., the IPv6 Unspecified Address, an IPv6
* multicast address, or an address known by the ICMP message
* originator to be an IPv6 anycast address.
*/
if(FNET_IP6_ADDR_IS_MULTICAST(src_ip) || FNET_IP6_ADDR_EQUAL(&fnet_ip6_addr_any, src_ip))
{
goto FREE_NB;
}
/* Construct ICMPv6 error header.*/
if((nb_header = fnet_netbuf_new((sizeof(fnet_icmp6_err_header_t)), FNET_FALSE)) == 0)
goto FREE_NB;
icmp6_err_header = nb_header->data_ptr;
icmp6_err_header->icmp6_header.type = type;
icmp6_err_header->icmp6_header.code = code;
icmp6_err_header->data = fnet_htonl(param);
origin_nb = fnet_netbuf_concat(nb_header, origin_nb);
fnet_icmp6_output( netif, dest_ip/*ipsrc*/, src_ip/*ipdest*/, 0, origin_nb);
return;
FREE_NB:
fnet_netbuf_free_chain(origin_nb);
}
}
/************************************************************************
* NAME: fnet_icmp6_input
*
* DESCRIPTION: ICMPv6 input function.
*************************************************************************/
static void fnet_icmp6_input(fnet_netif_t *netif, struct sockaddr *src_addr, struct sockaddr *dest_addr, fnet_netbuf_t *nb, fnet_netbuf_t *ip6_nb)
{
fnet_icmp6_header_t *hdr;
fnet_netbuf_t *tmp_nb;
unsigned short sum;
fnet_ip6_addr_t *src_ip;
fnet_ip6_addr_t *dest_ip;
fnet_prot_notify_t prot_cmd;
if((netif != 0) && (nb != 0))
{
/* The header must reside in contiguous area of memory. */
if((tmp_nb = fnet_netbuf_pullup(nb, sizeof(fnet_icmp6_header_t))) == 0)
{
goto DISCARD;
}
nb = tmp_nb;
hdr = nb->data_ptr;
dest_ip = &((struct sockaddr_in6 *)(dest_addr))->sin6_addr.s6_addr;
src_ip = &((struct sockaddr_in6 *)(src_addr))->sin6_addr.s6_addr;
/* Drop Multicast loopback.*/
#if FNET_CFG_LOOPBACK
if ((netif == FNET_LOOP_IF) && FNET_IP6_ADDR_IS_MULTICAST(dest_ip))
{
goto DISCARD;
}
#endif /* FNET_CFG_LOOPBACK */
/* Verify the checksum. */
sum = fnet_checksum_pseudo_start( nb, FNET_HTONS((unsigned short)FNET_IP_PROTOCOL_ICMP6), (unsigned short)nb->total_length );
sum = fnet_checksum_pseudo_end( sum, (char *)src_ip, (char *)dest_ip, sizeof(fnet_ip6_addr_t) );
if(sum)
goto DISCARD;
/************************************************************
* Process incoming ICMPv6 packets.
*************************************************************/
switch (hdr->type)
{
/**************************
* Neighbor Solicitation.
**************************/
case FNET_ICMP6_TYPE_NEIGHBOR_SOLICITATION:
fnet_nd6_neighbor_solicitation_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
/**************************
* Neighbor Advertisemnt.
**************************/
case FNET_ICMP6_TYPE_NEIGHBOR_ADVERTISEMENT:
fnet_nd6_neighbor_advertisement_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
/**************************
* Router Advertisemnt.
**************************/
case FNET_ICMP6_TYPE_ROUTER_ADVERTISEMENT:
fnet_nd6_router_advertisement_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
/**************************
* Router Advertisemnt.
**************************/
case FNET_ICMP6_TYPE_REDIRECT:
fnet_nd6_redirect_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
#if FNET_CFG_MLD
/**************************
* Multicast Listener Query.
**************************/
case FNET_ICMP6_TYPE_MULTICAST_LISTENER_QUERY:
fnet_mld_query_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
#endif
/**************************
* Echo Request.
* RFC4443 4.1: Every node MUST implement an ICMPv6 Echo responder function that
* receives Echo Requests and originates corresponding Echo Replies.
**************************/
case FNET_ICMP6_TYPE_ECHO_REQ:
hdr->type = FNET_ICMP6_TYPE_ECHO_REPLY;
/* RFC4443: the source address of the reply MUST be a unicast
* address belonging to the interface on which
* the Echo Request message was received.*/
if(FNET_IP6_ADDR_IS_MULTICAST(dest_ip))
dest_ip = FNET_NULL;
fnet_icmp6_output(netif, dest_ip/*ipsrc*/, src_ip/*ipdest*/, 0, nb);
fnet_netbuf_free_chain(ip6_nb);
break;
#if FNET_CFG_IP6_PMTU_DISCOVERY
/**************************
* Packet Too Big Message.
**************************/
case FNET_ICMP6_TYPE_PACKET_TOOBIG:
if(netif->pmtu) /* If PMTU is enabled for the interface.*/
{
unsigned long pmtu;
fnet_icmp6_err_header_t *icmp6_err = nb->data_ptr;
/* The header must reside in contiguous area of memory. */
if((tmp_nb = fnet_netbuf_pullup(nb, sizeof(fnet_icmp6_err_header_t))) == 0)
{
goto DISCARD;
}
nb = tmp_nb;
/* RFC 1981.Upon receipt of such a
* message, the source node reduces its assumed PMTU for the path based
* on the MTU of the constricting hop as reported in the Packet Too Big
* message.*/
pmtu = fnet_ntohl(icmp6_err->data);
/* A node MUST NOT increase its estimate of the Path MTU in response to
* the contents of a Packet Too Big message. */
if(netif->pmtu > pmtu)
{
fnet_netif_set_pmtu(netif, pmtu);
}
}
goto DISCARD;
#endif
/**************************
* Destination Unreachable.
**************************/
case FNET_ICMP6_TYPE_DEST_UNREACH:
switch(hdr->code)
{
case FNET_ICMP6_CODE_DU_NO_ROUTE: /* No route to destination. */
case FNET_ICMP6_CODE_DU_BEYOND_SCOPE: /* Beyond scope of source address.*/
prot_cmd = FNET_PROT_NOTIFY_UNREACH_NET;
break;
case FNET_ICMP6_CODE_DU_ADMIN_PROHIBITED: /* Communication with destination administratively prohibited. */
case FNET_ICMP6_CODE_DU_ADDR_UNREACH: /* Address unreachable.*/
prot_cmd = FNET_PROT_NOTIFY_UNREACH_HOST;
break;
case FNET_ICMP6_CODE_DU_PORT_UNREACH: /* Port unreachable.*/
prot_cmd = FNET_PROT_NOTIFY_UNREACH_PORT;
break;
default:
goto DISCARD;
}
/* Protocol notification.*/
{
fnet_ip6_header_t *ip_header;
fnet_prot_if_t *protocol;
unsigned int hdr_err_length = sizeof(fnet_icmp6_err_header_t) + sizeof(fnet_ip6_header_t);
unsigned int hdr_err_data_length = hdr_err_length + 8; /* 8 bytes is enough for transport protocol (port numbers).*/
if(nb->total_length < hdr_err_data_length)
{
goto DISCARD;
}
if(nb->total_length > hdr_err_data_length)
{
fnet_netbuf_trim(&nb, (int)(hdr_err_data_length - nb->total_length));
}
if((tmp_nb = fnet_netbuf_pullup(nb, (int)nb->total_length)) == 0) /* The header must reside in contiguous area of memory.*/
{
goto DISCARD;
}
nb = tmp_nb;
ip_header = (fnet_ip6_header_t *)((char *)nb->data_ptr + sizeof(fnet_icmp6_err_header_t));
if((protocol = fnet_prot_find(AF_INET6, SOCK_UNSPEC, ip_header->next_header)) != 0)
{
if(protocol->prot_control_input)
{
struct sockaddr err_src_addr;
struct sockaddr err_dest_addr;
/* Prepare addreses for upper protocol.*/
fnet_ip6_set_socket_addr(netif, ip_header, &err_src_addr, &err_dest_addr );
fnet_netbuf_trim(&nb, (int)(hdr_err_length)); /* Cut the ICMP error header.*/
protocol->prot_control_input(prot_cmd, &err_src_addr, &err_dest_addr, nb);
}
}
}
goto DISCARD;
default:
goto DISCARD;
}
}
else
{
DISCARD:
fnet_netbuf_free_chain(ip6_nb);
fnet_netbuf_free_chain(nb);
}
}
/************************************************************************
* NAME: fnet_icmp6_input
*
* DESCRIPTION: ICMPv6 input function.
*************************************************************************/
static void fnet_icmp6_input(fnet_netif_t *netif, fnet_ip6_addr_t *src_ip, fnet_ip6_addr_t *dest_ip, fnet_netbuf_t *nb, fnet_netbuf_t *ip6_nb)
{
fnet_icmp6_header_t *hdr;
fnet_netbuf_t *tmp_nb;
unsigned short sum;
if((netif != 0) && (nb != 0))
{
/* The header must reside in contiguous area of memory. */
if((tmp_nb = fnet_netbuf_pullup(nb, sizeof(fnet_icmp6_header_t))) == 0)
{
goto DISCARD;
}
nb = tmp_nb;
hdr = nb->data_ptr;
/* Drop Multicast loopback.*/
#if FNET_CFG_LOOPBACK
if ((netif == FNET_LOOP_IF) && FNET_IP6_ADDR_IS_MULTICAST(dest_ip))
{
goto DISCARD;
}
#endif /* FNET_CFG_LOOPBACK */
/* Verify the checksum. */
sum = fnet_checksum_pseudo_start( nb, FNET_HTONS((unsigned short)FNET_IP_PROTOCOL_ICMP6), (unsigned short)nb->total_length );
sum = fnet_checksum_pseudo_end( sum, (char *)src_ip, (char *)dest_ip, sizeof(fnet_ip6_addr_t) );
if(sum)
goto DISCARD;
/************************************************************
* Process incoming ICMPv6 packets.
*************************************************************/
switch (hdr->type)
{
/**************************
* Neighbor Solicitation.
**************************/
case FNET_ICMP6_TYPE_NEIGHBOR_SOLICITATION:
fnet_nd6_neighbor_solicitation_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
/**************************
* Neighbor Advertisemnt.
**************************/
case FNET_ICMP6_TYPE_NEIGHBOR_ADVERTISEMENT:
fnet_nd6_neighbor_advertisement_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
/**************************
* Router Advertisemnt.
**************************/
case FNET_ICMP6_TYPE_ROUTER_ADVERTISEMENT:
fnet_nd6_router_advertisement_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
/**************************
* Router Advertisemnt.
**************************/
case FNET_ICMP6_TYPE_REDIRECT:
fnet_nd6_redirect_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
#if FNET_CFG_MLD
/**************************
* Multicast Listener Query.
**************************/
case FNET_ICMP6_TYPE_MULTICAST_LISTENER_QUERY:
fnet_mld_query_receive(netif, src_ip, dest_ip, nb, ip6_nb);
break;
#endif
/**************************
* Echo Request.
* RFC4443 4.1: Every node MUST implement an ICMPv6 Echo responder function that
* receives Echo Requests and originates corresponding Echo Replies.
**************************/
case FNET_ICMP6_TYPE_ECHO_REQ:
hdr->type = FNET_ICMP6_TYPE_ECHO_REPLY;
/* RFC4443: the source address of the reply MUST be a unicast
* address belonging to the interface on which
* the Echo Request message was received.*/
if(FNET_IP6_ADDR_IS_MULTICAST(dest_ip))
dest_ip = FNET_NULL;
fnet_icmp6_output(netif, dest_ip/*ipsrc*/, src_ip/*ipdest*/, 0, nb); //MD
fnet_netbuf_free_chain(ip6_nb);
break;
#if FNET_CFG_IP6_PMTU_DISCOVERY
/**************************
* Packet Too Big Message.
**************************/
case FNET_ICMP6_TYPE_PACKET_TOOBIG:
if(netif->pmtu) /* If PMTU is enabled for the interface.*/
{
unsigned long pmtu;
fnet_icmp6_err_header_t *icmp6_err = nb->data_ptr;
/* The header must reside in contiguous area of memory. */
if((tmp_nb = fnet_netbuf_pullup(nb, sizeof(fnet_icmp6_err_header_t))) == 0)
{
goto DISCARD;
}
nb = tmp_nb;
/* RFC 1981.Upon receipt of such a
* message, the source node reduces its assumed PMTU for the path based
* on the MTU of the constricting hop as reported in the Packet Too Big
* message.*/
pmtu = fnet_ntohl(icmp6_err->data);
/* A node MUST NOT increase its estimate of the Path MTU in response to
* the contents of a Packet Too Big message. */
if(netif->pmtu > pmtu)
{
fnet_netif_set_pmtu(netif, pmtu);
}
}
goto DISCARD;
#endif
default:
goto DISCARD;
}
}
else
{
DISCARD:
fnet_netbuf_free_chain(ip6_nb);
fnet_netbuf_free_chain(nb);
}
}
