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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** 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_ipv6.h"
#include "nx_icmpv6.h"
#ifdef NX_IPSEC_ENABLE
#include "nx_ipsec.h"
#endif /* NX_IPSEC_ENABLE */
#ifdef FEATURE_NX_IPV6
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_icmpv6_process_echo_request PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This internal function processes incoming echo request message. */
/* It validates the echo request and sends an echo reply back to the */
/* sender. Note that when formulating an echo reply, the function */
/* updates the corresponding IPv6 and ICMPv6 header. The content */
/* of the ICMP echo request message is untouched. The ICMPv6 */
/* checksum computation also takes a shortcut by adjusting the */
/* original checksum values for ICMPv6 header field changes. */
/* */
/* INPUT */
/* */
/* ip_ptr IP stack instance */
/* packet_ptr Received echo request packet */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* _nx_packet_release Release packet back to the packet pool */
/* _nx_ipv6_packet_send Transmit IPv6 packet to remote host */
/* */
/* CALLED BY */
/* */
/* _nx_icmpv6_packet_process Main ICMPv6 packet handler */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Yuxin Zhou Initial Version 6.0 */
/* 09-30-2020 Yuxin Zhou Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
VOID _nx_icmpv6_process_echo_request(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{
UINT status;
ULONG tmp;
USHORT checksum;
#if defined(NX_DISABLE_ICMPV6_TX_CHECKSUM) || defined(NX_ENABLE_INTERFACE_CAPABILITY) || defined(NX_IPSEC_ENABLE)
UINT compute_checksum = 1;
#endif /* defined(NX_DISABLE_ICMPV6_TX_CHECKSUM) || defined(NX_ENABLE_INTERFACE_CAPABILITY) || defined(NX_IPSEC_ENABLE) */
NX_ICMPV6_HEADER *header_ptr;
NX_IPV6_HEADER *ipv6_header;
ULONG hop_limit = 255;
NXD_ADDRESS dest_addr;
NX_INTERFACE *interface_ptr;
#ifdef NX_IPSEC_ENABLE
ULONG data_offset;
VOID *sa = NX_NULL;
NXD_ADDRESS src_addr;
UINT ret;
#endif /* NX_IPSEC_ENABLE */
/* Add debug information. */
NX_PACKET_DEBUG(__FILE__, __LINE__, packet_ptr);
#ifndef NX_DISABLE_RX_SIZE_CHECKING
/* Check packet length. */
if (packet_ptr -> nx_packet_length < sizeof(NX_ICMPV6_ECHO))
{
#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 */
/* Points to the ICMP message header. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
header_ptr = (NX_ICMPV6_HEADER *)packet_ptr -> nx_packet_prepend_ptr;
/* Points to the IPv6 header. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
ipv6_header = (NX_IPV6_HEADER *)packet_ptr -> nx_packet_ip_header;
/* Check if the destination address is multicast address. */
if (IPv6_Address_Type(ipv6_header -> nx_ip_header_destination_ip) & IPV6_ADDRESS_MULTICAST)
{
/* Yes, Set the interface. */
interface_ptr = packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address_attached;
/* Find a suitable outgoing address. */
status = _nxd_ipv6_interface_find(ip_ptr, ipv6_header -> nx_ip_header_source_ip,
&packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr, interface_ptr);
/* Cannot find usable outgoing interface. */
if (status != NX_SUCCESS)
{
/* Release the packet. */
_nx_packet_release(packet_ptr);
return;
}
}
else
{
/* Make sure the interface IP address has been validated. */
if (packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address_state != NX_IPV6_ADDR_STATE_VALID)
{
/* Not validated, so release the packet and abort.*/
_nx_packet_release(packet_ptr);
return;
}
}
/* Discard the packet if source address is unspecified (::). */
if (CHECK_UNSPECIFIED_ADDRESS(ipv6_header -> nx_ip_header_source_ip))
{
/* NULL address in the header. Release the packet and abort. */
_nx_packet_release(packet_ptr);
return;
}
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP pings received count. */
ip_ptr -> nx_ip_pings_received++;
#endif
/* Respond to echo request packet. */
/* Set up the destination address. */
dest_addr.nxd_ip_version = NX_IP_VERSION_V6;
dest_addr.nxd_ip_address.v6[0] = ipv6_header -> nx_ip_header_source_ip[0];
dest_addr.nxd_ip_address.v6[1] = ipv6_header -> nx_ip_header_source_ip[1];
dest_addr.nxd_ip_address.v6[2] = ipv6_header -> nx_ip_header_source_ip[2];
dest_addr.nxd_ip_address.v6[3] = ipv6_header -> nx_ip_header_source_ip[3];
#ifdef NX_IPSEC_ENABLE
/* Set up the source address for IPSec SA lookup. */
src_addr.nxd_ip_version = NX_IP_VERSION_V6;
COPY_IPV6_ADDRESS(packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address,
src_addr.nxd_ip_address.v6);
/* Check if IPsec is enabled. */
if (ip_ptr -> nx_ip_packet_egress_sa_lookup != NX_NULL)
{
/* Check for possible SA match. */
ret = ip_ptr -> nx_ip_packet_egress_sa_lookup(ip_ptr, /* IP ptr */
&src_addr, /* src_addr */
&dest_addr, /* dest_addr */
NX_PROTOCOL_ICMPV6, /* protocol */
0, /* port, not used. */
0, /* port, not used. */
&data_offset, &sa, (NX_ICMPV6_ECHO_REPLY_TYPE << 8));
/* We have a match; apply IPSec processing on this packet. */
if (ret == NX_IPSEC_TRAFFIC_PROTECT)
{
/* Make sure the outgoing packet has enough space for IPsec header info. */
if ((ULONG)(packet_ptr -> nx_packet_prepend_ptr - packet_ptr -> nx_packet_data_start) <
(NX_IPv6_PACKET + data_offset))
{
/* Not enough space. Release the packet and return. */
_nx_packet_release(packet_ptr);
return;
}
/* Save the SA to the packet. */
packet_ptr -> nx_packet_ipsec_sa_ptr = sa;
}
else if (ret == NX_IPSEC_TRAFFIC_DROP || ret == NX_IPSEC_TRAFFIC_PENDING_IKEV2)
{
/* IPSec SA disallows this packet. Drop the packet and return. */
_nx_packet_release(packet_ptr);
return;
}
else
{
/* IPSec SA indicates the packet requires no IPSec processing.
Zero out sa information. */
packet_ptr -> nx_packet_ipsec_sa_ptr = NX_NULL;
}
}
#endif /* NX_IPSEC_ENABLE */
/* Change the type to Echo Reply and send back the message to the caller. */
header_ptr -> nx_icmpv6_header_type = NX_ICMPV6_ECHO_REPLY_TYPE;
#ifdef NX_DISABLE_ICMPV6_TX_CHECKSUM
compute_checksum = 0;
#endif /* NX_DISABLE_ICMPV6_TX_CHECKSUM */
#ifdef NX_ENABLE_INTERFACE_CAPABILITY
if (packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address_attached -> nx_interface_capability_flag & NX_INTERFACE_CAPABILITY_ICMPV6_TX_CHECKSUM)
{
compute_checksum = 0;
}
#endif /* NX_ENABLE_INTERFACE_CAPABILITY */
#ifdef NX_IPSEC_ENABLE
if ((packet_ptr -> nx_packet_ipsec_sa_ptr != NX_NULL) && (((NX_IPSEC_SA *)(packet_ptr -> nx_packet_ipsec_sa_ptr)) -> nx_ipsec_sa_encryption_method != NX_CRYPTO_NONE))
{
compute_checksum = 1;
}
#endif
#if defined(NX_DISABLE_ICMPV6_TX_CHECKSUM) || defined(NX_ENABLE_INTERFACE_CAPABILITY) || defined(NX_IPSEC_ENABLE)
if (compute_checksum)
#endif /* defined(NX_DISABLE_ICMPV6_TX_CHECKSUM) || defined(NX_ENABLE_INTERFACE_CAPABILITY) || defined(NX_IPSEC_ENABLE) */
{
/* Take a short cut to fix the checksum. */
checksum = header_ptr -> nx_icmpv6_header_checksum;
/* Change to host byte order. */
NX_CHANGE_USHORT_ENDIAN(checksum);
tmp = ((USHORT)(~checksum) & 0xFFFF);
/* The original ICMP type is ECHO_REQUEST. */
tmp -= (NX_ICMPV6_ECHO_REQUEST_TYPE << 8);
if (tmp > (ULONG)0x80000000)
{
tmp = (tmp & 0xFFFF) - 1;
}
tmp += (ULONG)(header_ptr -> nx_icmpv6_header_type << 8);
/* Compute the checksum differently depending if the echo request sends to
a multicast or unicast address. */
if ((IPv6_Address_Type(ipv6_header -> nx_ip_header_destination_ip) &
IPV6_ADDRESS_MULTICAST) == IPV6_ADDRESS_MULTICAST)
{
/* Compute the checksum for a multicast address. */
header_ptr -> nx_icmpv6_header_checksum = 0;
tmp = _nx_ip_checksum_compute(packet_ptr,
NX_PROTOCOL_ICMPV6,
(UINT)packet_ptr -> nx_packet_length,
packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address,
ipv6_header -> nx_ip_header_source_ip);
tmp = ~tmp;
header_ptr -> nx_icmpv6_header_checksum = (USHORT)(tmp);
NX_CHANGE_USHORT_ENDIAN(header_ptr -> nx_icmpv6_header_checksum);
hop_limit = 255;
}
else
{
/* Compute the checksum for a unicast address. */
hop_limit = ip_ptr -> nx_ipv6_hop_limit;
tmp = (tmp >> 16) + (tmp & 0xFFFF);
/* Do it again in case of carrying */
tmp = (tmp >> 16) + (tmp & 0xFFFF);
header_ptr -> nx_icmpv6_header_checksum = (USHORT)(~tmp);
NX_CHANGE_USHORT_ENDIAN(header_ptr -> nx_icmpv6_header_checksum);
}
}
#if defined(NX_DISABLE_ICMPV6_TX_CHECKSUM) || defined(NX_ENABLE_INTERFACE_CAPABILITY)
else
{
/* Fix the bug when NX_DISABLE_ICMP_TX_CHECKSUM has been set, the nx_icmpv6_header_type is not modified. */
/* Change the type to Echo Reply and send back the message to the caller. */
header_ptr -> nx_icmpv6_header_checksum = 0;
if ((IPv6_Address_Type(ipv6_header -> nx_ip_header_destination_ip) &
IPV6_ADDRESS_MULTICAST) == IPV6_ADDRESS_MULTICAST)
{
hop_limit = 255;
}
else
{
hop_limit = ip_ptr -> nx_ipv6_hop_limit;
}
#ifdef NX_ENABLE_INTERFACE_CAPABILITY
packet_ptr -> nx_packet_interface_capability_flag |= NX_INTERFACE_CAPABILITY_ICMPV6_TX_CHECKSUM;
#endif /* NX_ENABLE_INTERFACE_CAPABILITY */
}
#endif
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP pings responded to count. */
ip_ptr -> nx_ip_pings_responded_to++;
#endif
/* Send the ICMP packet to the IP component. */
_nx_ipv6_packet_send(ip_ptr, packet_ptr, NX_PROTOCOL_ICMPV6,
packet_ptr -> nx_packet_length, hop_limit,
packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address,
dest_addr.nxd_ip_address.v6);
}
#endif /* FEATURE_NX_IPV6 */
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