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/***************************************************************************
* Copyright (c) 2024 Microsoft Corporation
* Copyright (c) 2025-present Eclipse ThreadX Contributors
*
* This program and the accompanying materials are made available under the
* terms of the MIT License which is available at
* https://opensource.org/licenses/MIT.
*
* SPDX-License-Identifier: MIT
**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Component */
/** */
/** Internet Control Message Protocol (ICMP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_packet.h"
#include "nx_ip.h"
#include "nx_ipv6.h"
#include "nx_icmpv6.h"
#ifdef FEATURE_NX_IPV6
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_icmpv6_process_redirect PORTABLE C */
/* 6.4.3 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function processes an incoming ICMPv6 redirect message. */
/* */
/* INPUT */
/* */
/* ip_ptr Pointer to IP control block */
/* packet_ptr ICMP packet pointer */
/* */
/* OUTPUT */
/* */
/* NONE */
/* */
/* CALLS */
/* */
/* IPv6_Address_Type Find IP address type. */
/* _nxd_ipv6_destination_table_find_next_hop */
/* Finds next hop address. */
/* _nxd_ipv6_router_lookup Routine that finds default */
/* router. */
/* _nx_icmpv6_validate_options Check for valid option headers */
/* _nx_nd_cache_find_entry Find entry in ND cache by IP */
/* address */
/* _nx_nd_cache_add Add entry to ND cache */
/* _nxd_ipv6_default_router_add_internal Update router list with */
/* redirect next hop */
/* _nx_icmpv6_send_queued_packets Transmit queued packets waiting */
/* for physical mapping */
/* */
/* CALLED BY */
/* */
/* _nx_icmpv6_packet_process Main ICMPv6 packet pocess */
/* */
/**************************************************************************/
#ifndef NX_DISABLE_ICMPV6_REDIRECT_PROCESS
VOID _nx_icmpv6_process_redirect(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{
NX_ICMPV6_REDIRECT_MESSAGE *redirect_ptr;
NX_IPV6_HEADER *ip_header;
UINT status;
ULONG source_address_type;
ULONG router_address[4];
ULONG error = 0;
ND_CACHE_ENTRY *nd_entry = NX_NULL;
ND_CACHE_ENTRY *NDCacheEntry = NX_NULL;
UINT i;
NX_ICMPV6_OPTION *option_ptr;
ULONG packet_length, option_length;
NX_IPV6_DEFAULT_ROUTER_ENTRY *rt_entry;
NX_INTERFACE *interface_ptr;
#ifdef NX_ENABLE_IPV6_PATH_MTU_DISCOVERY
NX_ICMPV6_OPTION_MTU *mtu_ptr;
#endif
ULONG mtu;
ULONG mtu_timeout;
NX_IPV6_DESTINATION_ENTRY *dest_entry_ptr;
/* Add debug information. */
NX_PACKET_DEBUG(__FILE__, __LINE__, packet_ptr);
#ifndef NX_DISABLE_RX_SIZE_CHECKING
if ((packet_ptr -> nx_packet_length < sizeof(NX_ICMPV6_REDIRECT_MESSAGE))
#ifndef NX_DISABLE_PACKET_CHAIN
|| (packet_ptr -> nx_packet_next) /* Ignore chained packet. */
#endif /* NX_DISABLE_PACKET_CHAIN */
)
{
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP invalid message count. */
ip_ptr -> nx_ip_icmp_invalid_packets++;
#endif
/* Invalid ICMP message, just release it. */
_nx_packet_release(packet_ptr);
return;
}
#endif /* NX_DISABLE_RX_SIZE_CHECKING */
/* Get interface pointer. */
interface_ptr = packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address_attached;
/* Initialize the MTU. */
mtu = interface_ptr -> nx_interface_ip_mtu_size;
mtu_timeout = NX_WAIT_FOREVER;
/* Locate the IPv6 header. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
ip_header = (NX_IPV6_HEADER *)(packet_ptr -> nx_packet_ip_header);
/* Locate the redirect message. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
redirect_ptr = (NX_ICMPV6_REDIRECT_MESSAGE *)(packet_ptr -> nx_packet_prepend_ptr);
/* RFC 2461 4.5 the IPv6 and ICMPv6 header fields. */
/* Convert the destination and target address to host byte order. */
NX_IPV6_ADDRESS_CHANGE_ENDIAN(redirect_ptr -> nx_icmpv6_redirect_target_address);
NX_IPV6_ADDRESS_CHANGE_ENDIAN(redirect_ptr -> nx_icmpv6_redirect_destination_address);
/* Verify that sender address is link-local address. */
source_address_type = IPv6_Address_Type(ip_header -> nx_ip_header_source_ip);
if ((source_address_type & 0xFF) != IPV6_ADDRESS_LINKLOCAL)
{
error = 1;
}
/* Verify that hop limit is 255 */
else if ((ip_header -> nx_ip_header_word_1 & 0xFF) != 0xFF)
{
error = 1;
}
/* Verifty that ICMP code is zero. */
else if (redirect_ptr -> nx_icmpv6_redirect_icmpv6_header.nx_icmpv6_header_code != 0)
{
error = 1;
}
/* The IP source address of the redirect is the same as the current first-hop
router for the specified ICMP destination address. */
/* First look for redirect in the destination table. */
if (_nxd_ipv6_destination_table_find_next_hop(ip_ptr, redirect_ptr -> nx_icmpv6_redirect_destination_address,
router_address) == NX_SUCCESS)
{
/* Make sure the source is the current 1st hop router. */
if (!CHECK_IPV6_ADDRESSES_SAME(router_address, ip_header -> nx_ip_header_source_ip))
{
error = 1;
}
}
/* Next check if the redirect is the default router. */
/* Suppress cast of pointer to pointer, since it is necessary */
else if (_nxd_ipv6_router_lookup(ip_ptr, interface_ptr, router_address, /*lint -e{929}*/ (void **)&NDCacheEntry))
{
/* No default router. */
error = 1;
}
/* Make sure the source is the current 1st hop router. */
if (!CHECK_IPV6_ADDRESSES_SAME(ip_header -> nx_ip_header_source_ip, router_address))
{
error = 1;
}
/* The destination address field may not be multicast. */
else if (IPv6_Address_Type(redirect_ptr -> nx_icmpv6_redirect_destination_address) & IPV6_ADDRESS_MULTICAST)
{
error = 1;
}
/* Is target address is different from destination address? */
else if (!(CHECK_IPV6_ADDRESSES_SAME(redirect_ptr -> nx_icmpv6_redirect_destination_address,
redirect_ptr -> nx_icmpv6_redirect_target_address)))
{
/* Yes, so the target is a router, therefore the target address must be link-local.*/
if ((IPv6_Address_Type(redirect_ptr -> nx_icmpv6_redirect_target_address) & IPV6_ADDRESS_LINKLOCAL) == 0)
{
/* It isn't. */
error = 1;
}
}
/* Release the packet if it fails these validation checks. */
if (error)
{
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP invalid packet error. */
ip_ptr -> nx_ip_icmp_invalid_packets++;
#endif /* NX_DISABLE_ICMP_INFO */
_nx_packet_release(packet_ptr);
return;
}
/* If there are additional options, it could be TLLA or the redirected header. */
if (packet_ptr -> nx_packet_length - sizeof(NX_ICMPV6_REDIRECT_MESSAGE))
{
/*lint -e{923} suppress cast between pointer and ULONG, since it is necessary */
option_ptr = (NX_ICMPV6_OPTION *)NX_UCHAR_POINTER_ADD(redirect_ptr, sizeof(NX_ICMPV6_REDIRECT_MESSAGE));
packet_length = packet_ptr -> nx_packet_length - (ULONG)sizeof(NX_ICMPV6_REDIRECT_MESSAGE);
/* Validate option fields. */
if (_nx_icmpv6_validate_options(option_ptr, (INT)packet_length, 0) == NX_NOT_SUCCESSFUL)
{
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP invalid packet error. */
ip_ptr -> nx_ip_icmp_invalid_packets++;
#endif /* NX_DISABLE_ICMP_INFO */
_nx_packet_release(packet_ptr);
return;
}
while (packet_length)
{
/* The packet contains target link layer address. */
if (option_ptr -> nx_icmpv6_option_type == ICMPV6_OPTION_TYPE_TRG_LINK_ADDR)
{
status = _nx_nd_cache_find_entry(ip_ptr, redirect_ptr -> nx_icmpv6_redirect_target_address, &nd_entry);
if (status != NX_SUCCESS)
{
/* The entry is not found in the ND cache table. Simply add it, and we are done. */
/*lint -e{929} -e{740} -e{826} suppress cast of pointer to pointer, since it is necessary */
if (_nx_nd_cache_add(ip_ptr, redirect_ptr -> nx_icmpv6_redirect_target_address,
interface_ptr,
(CHAR *)&option_ptr -> nx_icmpv6_option_data, 0, ND_CACHE_STATE_STALE,
packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr, &nd_entry) == NX_SUCCESS)
{
/* If the destination and target addresses are different, the redirect is to a router. */
if (!CHECK_IPV6_ADDRESSES_SAME(redirect_ptr -> nx_icmpv6_redirect_target_address,
redirect_ptr -> nx_icmpv6_redirect_destination_address))
{
/* We need to fill in the IsRouter field in the cache entry
with the default router. */
_nxd_ipv6_default_router_add_internal(ip_ptr,
redirect_ptr -> nx_icmpv6_redirect_target_address, /* TLLA in Redirect ICMPv6 options */
0,
interface_ptr,
NX_IPV6_ROUTE_TYPE_UNSOLICITATED, &rt_entry);
/* And cross link this entry with the entry in the router list. */
/*lint -e{644} suppress variable might not be initialized, since "rt_entry" was initialized in _nxd_ipv6_default_router_add_internal. */
/*lint -e{613} suppress possible use of null pointer, since "nd_entry" was set in _nx_nd_cache_add. */
nd_entry -> nx_nd_cache_is_router = rt_entry;
}
}
}
else
{
/* This entry already exists. If the mac address is the same, do not update the entry. Otherwise,
update the entry and set the state to STALE (RFC2461 7.2.3) */
ULONG mac_msw, mac_lsw, new_msw, new_lsw;
/*lint -e{928} suppress cast of pointer to pointer, since it is necessary */
UCHAR *new_mac = (UCHAR *)&option_ptr -> nx_icmpv6_option_data;
mac_msw = ((ULONG)(nd_entry -> nx_nd_cache_mac_addr[0]) << 8) | (nd_entry -> nx_nd_cache_mac_addr[1]);
new_msw = ((ULONG)(new_mac[0]) << 8) | (new_mac[1]);
mac_lsw = ((ULONG)(nd_entry -> nx_nd_cache_mac_addr[2]) << 24) | ((ULONG)(nd_entry -> nx_nd_cache_mac_addr[3]) << 16) |
((ULONG)(nd_entry -> nx_nd_cache_mac_addr[4]) << 8) | nd_entry -> nx_nd_cache_mac_addr[5];
new_lsw = ((ULONG)(new_mac[2]) << 24) | ((ULONG)(new_mac[3]) << 16) | ((ULONG)(new_mac[4]) << 8) | new_mac[5]; /* lgtm[cpp/overflow-buffer] */
if ((mac_msw != new_msw) || (mac_lsw != new_lsw)) /* If the new MAC is different. */
{
/* Update the MAC address. */
for (i = 0; i < 6; i++)
{
nd_entry -> nx_nd_cache_mac_addr[i] = new_mac[i];
}
/* Set the state to STALE. */
nd_entry -> nx_nd_cache_nd_status = ND_CACHE_STATE_STALE;
/* Set the interface. */
nd_entry -> nx_nd_cache_interface_ptr = interface_ptr;
}
/* If there are packets chained on the entry waiting to be transmitted: */
if (nd_entry -> nx_nd_cache_packet_waiting_head) /* There are packets waiting to be transmitted */
{
_nx_icmpv6_send_queued_packets(ip_ptr, nd_entry);
}
}
}
#ifdef NX_ENABLE_IPV6_PATH_MTU_DISCOVERY
else if (option_ptr -> nx_icmpv6_option_type == ICMPV6_OPTION_TYPE_MTU)
{
/* Get a local pointer to the MTU option. */
/*lint -e{929} -e{740} -e{826} suppress cast of pointer to pointer, since it is necessary */
mtu_ptr = (NX_ICMPV6_OPTION_MTU *)option_ptr;
/* Apply the router's next hop (on link) path MTU. */
mtu = mtu_ptr -> nx_icmpv6_option_mtu_path_mtu;
NX_CHANGE_ULONG_ENDIAN(mtu);
if (mtu < NX_MINIMUM_IPV6_PATH_MTU)
{
/* Update the timeout of MTU. */
mtu_timeout = NX_PATH_MTU_INCREASE_WAIT_INTERVAL_TICKS;
}
}
#endif /* NX_ENABLE_IPV6_PATH_MTU_DISCOVERY */
option_length = (UINT)(option_ptr -> nx_icmpv6_option_length << 3);
packet_length -= option_length;
/*lint -e{923} suppress cast between pointer and ULONG, since it is necessary */
option_ptr = (NX_ICMPV6_OPTION *)NX_UCHAR_POINTER_ADD(option_ptr, option_length);
}
}
/*
* If the packet contains target link layer address, we should have added the link layer address
* to the ND cache, and the next block is not executed.
* However if the packet does not contain target link layer address (thus nd_cache is NULL at
* this point, we create an entry.
*/
if (nd_entry == NX_NULL)
{
status = _nx_nd_cache_find_entry(ip_ptr, redirect_ptr -> nx_icmpv6_redirect_target_address, &nd_entry);
if (status != NX_SUCCESS)
{
if (_nx_nd_cache_add_entry(ip_ptr, redirect_ptr -> nx_icmpv6_redirect_target_address,
packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr, &nd_entry) != NX_SUCCESS)
{
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP invalid packet error. */
ip_ptr -> nx_ip_icmp_invalid_packets++;
#endif /* NX_DISABLE_ICMP_INFO */
/* Release the packet. */
_nx_packet_release(packet_ptr);
return;
}
}
}
/* Find/update existing entry or add a new one for this router in the destination table.
A new entry will be assigned default path MTU and MTU timeout values. */
status = _nx_icmpv6_dest_table_add(ip_ptr, redirect_ptr -> nx_icmpv6_redirect_destination_address,
&dest_entry_ptr, redirect_ptr -> nx_icmpv6_redirect_target_address,
mtu, mtu_timeout,
packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr);
if (status)
{
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP invalid packet error. */
ip_ptr -> nx_ip_icmp_invalid_packets++;
#endif /* NX_DISABLE_ICMP_INFO */
/* Release the packet. */
_nx_packet_release(packet_ptr);
return;
}
/* Cross link the nd_entry. */
/*lint -e{644} suppress variable might not be initialized, since "dest_entry_ptr" was initialized _nx_icmpv6_dest_table_find or _nx_icmpv6_dest_table_add. */
dest_entry_ptr -> nx_ipv6_destination_entry_nd_entry = nd_entry;
/* Release the packet. */
_nx_packet_release(packet_ptr);
}
#endif /* NX_DISABLE_ICMPV6_REDIRECT_PROCESS */
#endif /* FEATURE_NX_IPV6 */
|
