[mirror_edk2.git] / NetworkPkg / Ip4Dxe / Ip4Icmp.c

/** @file\r
\r
Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "Ip4Impl.h"\r
\r
IP4_ICMP_CLASS\r
  mIcmpClass[] = {\r
  { ICMP_ECHO_REPLY,        ICMP_QUERY_MESSAGE   },\r
  { 1,                      ICMP_INVALID_MESSAGE },\r
  { 2,                      ICMP_INVALID_MESSAGE },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_ERROR_MESSAGE   },\r
  { ICMP_SOURCE_QUENCH,     ICMP_ERROR_MESSAGE   },\r
  { ICMP_REDIRECT,          ICMP_ERROR_MESSAGE   },\r
  { 6,                      ICMP_INVALID_MESSAGE },\r
  { 7,                      ICMP_INVALID_MESSAGE },\r
  { ICMP_ECHO_REQUEST,      ICMP_QUERY_MESSAGE   },\r
  { 9,                      ICMP_INVALID_MESSAGE },\r
  { 10,                     ICMP_INVALID_MESSAGE },\r
  { ICMP_TIME_EXCEEDED,     ICMP_ERROR_MESSAGE   },\r
  { ICMP_PARAMETER_PROBLEM, ICMP_ERROR_MESSAGE   },\r
  { ICMP_TIMESTAMP,         ICMP_QUERY_MESSAGE   },\r
  { 14,                     ICMP_INVALID_MESSAGE },\r
  { ICMP_INFO_REQUEST,      ICMP_QUERY_MESSAGE   },\r
  { ICMP_INFO_REPLY,        ICMP_QUERY_MESSAGE   },\r
};\r
\r
EFI_IP4_ICMP_TYPE\r
  mIp4SupportedIcmp[23] = {\r
  { ICMP_ECHO_REPLY,        ICMP_DEFAULT_CODE         },\r
\r
  { ICMP_DEST_UNREACHABLE,  ICMP_NET_UNREACHABLE      },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_HOST_UNREACHABLE     },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_PROTO_UNREACHABLE    },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_PORT_UNREACHABLE     },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_FRAGMENT_FAILED      },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_SOURCEROUTE_FAILED   },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_NET_UNKNOWN          },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_HOST_UNKNOWN         },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_SOURCE_ISOLATED      },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_NET_PROHIBITED       },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_HOST_PROHIBITED      },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_NET_UNREACHABLE_TOS  },\r
  { ICMP_DEST_UNREACHABLE,  ICMP_HOST_UNREACHABLE_TOS },\r
\r
  { ICMP_SOURCE_QUENCH,     ICMP_DEFAULT_CODE         },\r
\r
  { ICMP_REDIRECT,          ICMP_NET_REDIRECT         },\r
  { ICMP_REDIRECT,          ICMP_HOST_REDIRECT        },\r
  { ICMP_REDIRECT,          ICMP_NET_TOS_REDIRECT     },\r
  { ICMP_REDIRECT,          ICMP_HOST_TOS_REDIRECT    },\r
\r
  { ICMP_ECHO_REQUEST,      ICMP_DEFAULT_CODE         },\r
\r
  { ICMP_TIME_EXCEEDED,     ICMP_TIMEOUT_IN_TRANSIT   },\r
  { ICMP_TIME_EXCEEDED,     ICMP_TIMEOUT_REASSEMBLE   },\r
\r
  { ICMP_PARAMETER_PROBLEM, ICMP_DEFAULT_CODE         },\r
};\r
\r
/**\r
  Process the ICMP redirect. Find the instance then update\r
  its route cache.\r
\r
  All kinds of redirect is treated as host redirect as\r
  specified by RFC1122 3.3.1.2:\r
  "Since the subnet mask appropriate to the destination\r
  address is generally not known, a Network Redirect\r
  message SHOULD be treated identically to a Host Redirect\r
  message;"\r
\r
  @param[in]  IpSb               The IP4 service binding instance that received\r
                                 the packet.\r
  @param[in]  Head               The IP head of the received ICMPpacket.\r
  @param[in]  Packet             The content of the ICMP redirect packet with IP\r
                                 head removed.\r
  @param[in]  Icmp               The buffer to store the ICMP error message if\r
                                 something is wrong.\r
\r
  @retval EFI_INVALID_PARAMETER  The parameter is invalid\r
  @retval EFI_SUCCESS            Successfully updated the route caches\r
\r
**/\r
EFI_STATUS\r
Ip4ProcessIcmpRedirect (\r
  IN IP4_SERVICE          *IpSb,\r
  IN IP4_HEAD             *Head,\r
  IN NET_BUF              *Packet,\r
  IN IP4_ICMP_ERROR_HEAD  *Icmp\r
  )\r
{\r
  LIST_ENTRY             *Entry;\r
  IP4_PROTOCOL           *Ip4Instance;\r
  IP4_ROUTE_CACHE_ENTRY  *CacheEntry;\r
  IP4_INTERFACE          *IpIf;\r
  IP4_ADDR               Gateway;\r
  IP4_ADDR               Src;\r
  IP4_ADDR               Dst;\r
\r
  //\r
  // Find the interface whose IP address is the source of the\r
  // orgianl IP packet.\r
  //\r
  IpIf    = Ip4FindInterface (IpSb, NTOHL (Icmp->IpHead.Src));\r
  Gateway = NTOHL (Icmp->Fourth);\r
\r
  //\r
  // discard the packet if the new gateway address it specifies\r
  // is not on the same connected net through which the Redirect\r
  // arrived. (RFC1122 3.2.2.2).\r
  //\r
  if ((IpIf == NULL) || !IP4_NET_EQUAL (Gateway, IpIf->Ip, IpIf->SubnetMask)) {\r
    NetbufFree (Packet);\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // Update each IP child's route cache on the interface.\r
  //\r
  NET_LIST_FOR_EACH (Entry, &IpIf->IpInstances) {\r
    Ip4Instance = NET_LIST_USER_STRUCT (Entry, IP4_PROTOCOL, AddrLink);\r
\r
    if (Ip4Instance->RouteTable == NULL) {\r
      continue;\r
    }\r
\r
    Dst        = NTOHL (Icmp->IpHead.Dst);\r
    Src        = NTOHL (Icmp->IpHead.Src);\r
    CacheEntry = Ip4FindRouteCache (Ip4Instance->RouteTable, Dst, Src);\r
\r
    //\r
    // Only update the route cache's gateway if the source of the\r
    // Redirect is the current first-hop gateway\r
    //\r
    if ((CacheEntry != NULL) && (NTOHL (Head->Src) == CacheEntry->NextHop)) {\r
      CacheEntry->NextHop = Gateway;\r
    }\r
  }\r
\r
  NetbufFree (Packet);\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Process the ICMP error packet. If it is an ICMP redirect packet,\r
  update call Ip4ProcessIcmpRedirect to update the IP instance's\r
  route cache, otherwise, deliver the packet to upper layer.\r
\r
  @param[in]  IpSb               The IP4 service that received the packet.\r
  @param[in]  Head               The IP4 head of the ICMP error packet\r
  @param[in]  Packet             The content of the ICMP error with IP4 head\r
                                 removed.\r
\r
  @retval EFI_SUCCESS            The ICMP error is processed successfully.\r
  @retval EFI_INVALID_PARAMETER  The packet is invalid\r
  @retval Others                 Failed to process the packet.\r
\r
**/\r
EFI_STATUS\r
Ip4ProcessIcmpError (\r
  IN IP4_SERVICE  *IpSb,\r
  IN IP4_HEAD     *Head,\r
  IN NET_BUF      *Packet\r
  )\r
{\r
  IP4_ICMP_ERROR_HEAD  Icmp;\r
\r
  if (Packet->TotalSize < sizeof (Icmp)) {\r
    NetbufFree (Packet);\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *)&Icmp);\r
\r
  //\r
  // If it is an ICMP redirect error, update the route cache\r
  // as RFC1122. Otherwise, demultiplex it to IP instances.\r
  //\r
  if (Icmp.Head.Type == ICMP_REDIRECT) {\r
    return Ip4ProcessIcmpRedirect (IpSb, Head, Packet, &Icmp);\r
  }\r
\r
  IP4_GET_CLIP_INFO (Packet)->Status = EFI_ICMP_ERROR;\r
  return Ip4Demultiplex (IpSb, Head, Packet, NULL, 0);\r
}\r
\r
/**\r
  Replay an ICMP echo request.\r
\r
  @param[in]  IpSb               The IP4 service that receivd the packet\r
  @param[in]  Head               The IP4 head of the ICMP error packet\r
  @param[in]  Packet             The content of the ICMP error with IP4 head\r
                                 removed.\r
\r
  @retval EFI_OUT_OF_RESOURCES   Failed to allocate resource.\r
  @retval EFI_SUCCESS            The ICMP Echo request is successfully answered.\r
  @retval Others                 Failed to answer the ICMP echo request.\r
\r
**/\r
EFI_STATUS\r
Ip4IcmpReplyEcho (\r
  IN IP4_SERVICE  *IpSb,\r
  IN IP4_HEAD     *Head,\r
  IN NET_BUF      *Packet\r
  )\r
{\r
  IP4_ICMP_QUERY_HEAD  *Icmp;\r
  NET_BUF              *Data;\r
  EFI_STATUS           Status;\r
  IP4_HEAD             ReplyHead;\r
\r
  //\r
  // make a copy the packet, it is really a bad idea to\r
  // send the MNP's buffer back to MNP.\r
  //\r
  Data = NetbufDuplicate (Packet, NULL, IP4_MAX_HEADLEN);\r
\r
  if (Data == NULL) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto ON_EXIT;\r
  }\r
\r
  //\r
  // Change the ICMP type to echo reply, exchange the source\r
  // and destination, then send it. The source is updated to\r
  // use specific destination. See RFC1122. SRR/RR option\r
  // update is omitted.\r
  //\r
  Icmp = (IP4_ICMP_QUERY_HEAD *)NetbufGetByte (Data, 0, NULL);\r
  ASSERT (Icmp != NULL);\r
  Icmp->Head.Type     = ICMP_ECHO_REPLY;\r
  Icmp->Head.Checksum = 0;\r
  Icmp->Head.Checksum = (UINT16)(~NetblockChecksum ((UINT8 *)Icmp, Data->TotalSize));\r
\r
  ReplyHead.Tos      = 0;\r
  ReplyHead.Fragment = 0;\r
  ReplyHead.Ttl      = 64;\r
  ReplyHead.Protocol = EFI_IP_PROTO_ICMP;\r
  ReplyHead.Src      = 0;\r
\r
  //\r
  // Ip4Output will select a source for us\r
  //\r
  ReplyHead.Dst = Head->Src;\r
\r
  Status = Ip4Output (\r
             IpSb,\r
             NULL,\r
             Data,\r
             &ReplyHead,\r
             NULL,\r
             0,\r
             IP4_ALLZERO_ADDRESS,\r
             Ip4SysPacketSent,\r
             NULL\r
             );\r
  if (EFI_ERROR (Status)) {\r
    NetbufFree (Data);\r
  }\r
\r
ON_EXIT:\r
  NetbufFree (Packet);\r
  return Status;\r
}\r
\r
/**\r
  Process the ICMP query message. If it is an ICMP echo\r
  request, answer it. Otherwise deliver it to upper layer.\r
\r
  @param[in]  IpSb               The IP4 service that receivd the packet\r
  @param[in]  Head               The IP4 head of the ICMP query packet\r
  @param[in]  Packet             The content of the ICMP query with IP4 head\r
                                 removed.\r
\r
  @retval EFI_INVALID_PARAMETER  The packet is invalid\r
  @retval EFI_SUCCESS            The ICMP query message is processed\r
  @retval Others                 Failed to process ICMP query.\r
\r
**/\r
EFI_STATUS\r
Ip4ProcessIcmpQuery (\r
  IN IP4_SERVICE  *IpSb,\r
  IN IP4_HEAD     *Head,\r
  IN NET_BUF      *Packet\r
  )\r
{\r
  IP4_ICMP_QUERY_HEAD  Icmp;\r
\r
  if (Packet->TotalSize < sizeof (Icmp)) {\r
    NetbufFree (Packet);\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *)&Icmp);\r
\r
  if (Icmp.Head.Type == ICMP_ECHO_REQUEST) {\r
    return Ip4IcmpReplyEcho (IpSb, Head, Packet);\r
  }\r
\r
  return Ip4Demultiplex (IpSb, Head, Packet, NULL, 0);\r
}\r
\r
/**\r
  Handle the ICMP packet. First validate the message format,\r
  then according to the message types, process it as query or\r
  error packet.\r
\r
  @param[in]  IpSb               The IP4 service that receivd the packet.\r
  @param[in]  Head               The IP4 head of the ICMP query packet.\r
  @param[in]  Packet             The content of the ICMP query with IP4 head\r
                                 removed.\r
\r
  @retval EFI_INVALID_PARAMETER  The packet is malformatted.\r
  @retval EFI_SUCCESS            The ICMP message is successfully processed.\r
  @retval Others                 Failed to handle ICMP packet.\r
\r
**/\r
EFI_STATUS\r
Ip4IcmpHandle (\r
  IN IP4_SERVICE  *IpSb,\r
  IN IP4_HEAD     *Head,\r
  IN NET_BUF      *Packet\r
  )\r
{\r
  IP4_ICMP_HEAD  Icmp;\r
  UINT16         Checksum;\r
\r
  if (Packet->TotalSize < sizeof (Icmp)) {\r
    goto DROP;\r
  }\r
\r
  NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *)&Icmp);\r
\r
  if (Icmp.Type > ICMP_TYPE_MAX) {\r
    goto DROP;\r
  }\r
\r
  Checksum = (UINT16)(~NetbufChecksum (Packet));\r
  if ((Icmp.Checksum != 0) && (Checksum != 0)) {\r
    goto DROP;\r
  }\r
\r
  if (mIcmpClass[Icmp.Type].IcmpClass == ICMP_ERROR_MESSAGE) {\r
    return Ip4ProcessIcmpError (IpSb, Head, Packet);\r
  } else if (mIcmpClass[Icmp.Type].IcmpClass == ICMP_QUERY_MESSAGE) {\r
    return Ip4ProcessIcmpQuery (IpSb, Head, Packet);\r
  }\r
\r
DROP:\r
  NetbufFree (Packet);\r
  return EFI_INVALID_PARAMETER;\r
}\r
Commit	Line	Data
	1	/** @file\r
	2	\r
	3	Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>\r
	4	SPDX-License-Identifier: BSD-2-Clause-Patent\r
	5	\r
	6	**/\r
	7	\r
	8	#include "Ip4Impl.h"\r
	9	\r
	10	IP4_ICMP_CLASS\r
	11	mIcmpClass[] = {\r
	12	{ ICMP_ECHO_REPLY, ICMP_QUERY_MESSAGE },\r
	13	{ 1, ICMP_INVALID_MESSAGE },\r
	14	{ 2, ICMP_INVALID_MESSAGE },\r
	15	{ ICMP_DEST_UNREACHABLE, ICMP_ERROR_MESSAGE },\r
	16	{ ICMP_SOURCE_QUENCH, ICMP_ERROR_MESSAGE },\r
	17	{ ICMP_REDIRECT, ICMP_ERROR_MESSAGE },\r
	18	{ 6, ICMP_INVALID_MESSAGE },\r
	19	{ 7, ICMP_INVALID_MESSAGE },\r
	20	{ ICMP_ECHO_REQUEST, ICMP_QUERY_MESSAGE },\r
	21	{ 9, ICMP_INVALID_MESSAGE },\r
	22	{ 10, ICMP_INVALID_MESSAGE },\r
	23	{ ICMP_TIME_EXCEEDED, ICMP_ERROR_MESSAGE },\r
	24	{ ICMP_PARAMETER_PROBLEM, ICMP_ERROR_MESSAGE },\r
	25	{ ICMP_TIMESTAMP, ICMP_QUERY_MESSAGE },\r
	26	{ 14, ICMP_INVALID_MESSAGE },\r
	27	{ ICMP_INFO_REQUEST, ICMP_QUERY_MESSAGE },\r
	28	{ ICMP_INFO_REPLY, ICMP_QUERY_MESSAGE },\r
	29	};\r
	30	\r
	31	EFI_IP4_ICMP_TYPE\r
	32	mIp4SupportedIcmp[23] = {\r
	33	{ ICMP_ECHO_REPLY, ICMP_DEFAULT_CODE },\r
	34	\r
	35	{ ICMP_DEST_UNREACHABLE, ICMP_NET_UNREACHABLE },\r
	36	{ ICMP_DEST_UNREACHABLE, ICMP_HOST_UNREACHABLE },\r
	37	{ ICMP_DEST_UNREACHABLE, ICMP_PROTO_UNREACHABLE },\r
	38	{ ICMP_DEST_UNREACHABLE, ICMP_PORT_UNREACHABLE },\r
	39	{ ICMP_DEST_UNREACHABLE, ICMP_FRAGMENT_FAILED },\r
	40	{ ICMP_DEST_UNREACHABLE, ICMP_SOURCEROUTE_FAILED },\r
	41	{ ICMP_DEST_UNREACHABLE, ICMP_NET_UNKNOWN },\r
	42	{ ICMP_DEST_UNREACHABLE, ICMP_HOST_UNKNOWN },\r
	43	{ ICMP_DEST_UNREACHABLE, ICMP_SOURCE_ISOLATED },\r
	44	{ ICMP_DEST_UNREACHABLE, ICMP_NET_PROHIBITED },\r
	45	{ ICMP_DEST_UNREACHABLE, ICMP_HOST_PROHIBITED },\r
	46	{ ICMP_DEST_UNREACHABLE, ICMP_NET_UNREACHABLE_TOS },\r
	47	{ ICMP_DEST_UNREACHABLE, ICMP_HOST_UNREACHABLE_TOS },\r
	48	\r
	49	{ ICMP_SOURCE_QUENCH, ICMP_DEFAULT_CODE },\r
	50	\r
	51	{ ICMP_REDIRECT, ICMP_NET_REDIRECT },\r
	52	{ ICMP_REDIRECT, ICMP_HOST_REDIRECT },\r
	53	{ ICMP_REDIRECT, ICMP_NET_TOS_REDIRECT },\r
	54	{ ICMP_REDIRECT, ICMP_HOST_TOS_REDIRECT },\r
	55	\r
	56	{ ICMP_ECHO_REQUEST, ICMP_DEFAULT_CODE },\r
	57	\r
	58	{ ICMP_TIME_EXCEEDED, ICMP_TIMEOUT_IN_TRANSIT },\r
	59	{ ICMP_TIME_EXCEEDED, ICMP_TIMEOUT_REASSEMBLE },\r
	60	\r
	61	{ ICMP_PARAMETER_PROBLEM, ICMP_DEFAULT_CODE },\r
	62	};\r
	63	\r
	64	/**\r
	65	Process the ICMP redirect. Find the instance then update\r
	66	its route cache.\r
	67	\r
	68	All kinds of redirect is treated as host redirect as\r
	69	specified by RFC1122 3.3.1.2:\r
	70	"Since the subnet mask appropriate to the destination\r
	71	address is generally not known, a Network Redirect\r
	72	message SHOULD be treated identically to a Host Redirect\r
	73	message;"\r
	74	\r
	75	@param[in] IpSb The IP4 service binding instance that received\r
	76	the packet.\r
	77	@param[in] Head The IP head of the received ICMPpacket.\r
	78	@param[in] Packet The content of the ICMP redirect packet with IP\r
	79	head removed.\r
	80	@param[in] Icmp The buffer to store the ICMP error message if\r
	81	something is wrong.\r
	82	\r
	83	@retval EFI_INVALID_PARAMETER The parameter is invalid\r
	84	@retval EFI_SUCCESS Successfully updated the route caches\r
	85	\r
	86	**/\r
	87	EFI_STATUS\r
	88	Ip4ProcessIcmpRedirect (\r
	89	IN IP4_SERVICE *IpSb,\r
	90	IN IP4_HEAD *Head,\r
	91	IN NET_BUF *Packet,\r
	92	IN IP4_ICMP_ERROR_HEAD *Icmp\r
	93	)\r
	94	{\r
	95	LIST_ENTRY *Entry;\r
	96	IP4_PROTOCOL *Ip4Instance;\r
	97	IP4_ROUTE_CACHE_ENTRY *CacheEntry;\r
	98	IP4_INTERFACE *IpIf;\r
	99	IP4_ADDR Gateway;\r
	100	IP4_ADDR Src;\r
	101	IP4_ADDR Dst;\r
	102	\r
	103	//\r
	104	// Find the interface whose IP address is the source of the\r
	105	// orgianl IP packet.\r
	106	//\r
	107	IpIf = Ip4FindInterface (IpSb, NTOHL (Icmp->IpHead.Src));\r
	108	Gateway = NTOHL (Icmp->Fourth);\r
	109	\r
	110	//\r
	111	// discard the packet if the new gateway address it specifies\r
	112	// is not on the same connected net through which the Redirect\r
	113	// arrived. (RFC1122 3.2.2.2).\r
	114	//\r
	115	if ((IpIf == NULL) \|\| !IP4_NET_EQUAL (Gateway, IpIf->Ip, IpIf->SubnetMask)) {\r
	116	NetbufFree (Packet);\r
	117	return EFI_INVALID_PARAMETER;\r
	118	}\r
	119	\r
	120	//\r
	121	// Update each IP child's route cache on the interface.\r
	122	//\r
	123	NET_LIST_FOR_EACH (Entry, &IpIf->IpInstances) {\r
	124	Ip4Instance = NET_LIST_USER_STRUCT (Entry, IP4_PROTOCOL, AddrLink);\r
	125	\r
	126	if (Ip4Instance->RouteTable == NULL) {\r
	127	continue;\r
	128	}\r
	129	\r
	130	Dst = NTOHL (Icmp->IpHead.Dst);\r
	131	Src = NTOHL (Icmp->IpHead.Src);\r
	132	CacheEntry = Ip4FindRouteCache (Ip4Instance->RouteTable, Dst, Src);\r
	133	\r
	134	//\r
	135	// Only update the route cache's gateway if the source of the\r
	136	// Redirect is the current first-hop gateway\r
	137	//\r
	138	if ((CacheEntry != NULL) && (NTOHL (Head->Src) == CacheEntry->NextHop)) {\r
	139	CacheEntry->NextHop = Gateway;\r
	140	}\r
	141	}\r
	142	\r
	143	NetbufFree (Packet);\r
	144	return EFI_SUCCESS;\r
	145	}\r
	146	\r
	147	/**\r
	148	Process the ICMP error packet. If it is an ICMP redirect packet,\r
	149	update call Ip4ProcessIcmpRedirect to update the IP instance's\r
	150	route cache, otherwise, deliver the packet to upper layer.\r
	151	\r
	152	@param[in] IpSb The IP4 service that received the packet.\r
	153	@param[in] Head The IP4 head of the ICMP error packet\r
	154	@param[in] Packet The content of the ICMP error with IP4 head\r
	155	removed.\r
	156	\r
	157	@retval EFI_SUCCESS The ICMP error is processed successfully.\r
	158	@retval EFI_INVALID_PARAMETER The packet is invalid\r
	159	@retval Others Failed to process the packet.\r
	160	\r
	161	**/\r
	162	EFI_STATUS\r
	163	Ip4ProcessIcmpError (\r
	164	IN IP4_SERVICE *IpSb,\r
	165	IN IP4_HEAD *Head,\r
	166	IN NET_BUF *Packet\r
	167	)\r
	168	{\r
	169	IP4_ICMP_ERROR_HEAD Icmp;\r
	170	\r
	171	if (Packet->TotalSize < sizeof (Icmp)) {\r
	172	NetbufFree (Packet);\r
	173	return EFI_INVALID_PARAMETER;\r
	174	}\r
	175	\r
	176	NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *)&Icmp);\r
	177	\r
	178	//\r
	179	// If it is an ICMP redirect error, update the route cache\r
	180	// as RFC1122. Otherwise, demultiplex it to IP instances.\r
	181	//\r
	182	if (Icmp.Head.Type == ICMP_REDIRECT) {\r
	183	return Ip4ProcessIcmpRedirect (IpSb, Head, Packet, &Icmp);\r
	184	}\r
	185	\r
	186	IP4_GET_CLIP_INFO (Packet)->Status = EFI_ICMP_ERROR;\r
	187	return Ip4Demultiplex (IpSb, Head, Packet, NULL, 0);\r
	188	}\r
	189	\r
	190	/**\r
	191	Replay an ICMP echo request.\r
	192	\r
	193	@param[in] IpSb The IP4 service that receivd the packet\r
	194	@param[in] Head The IP4 head of the ICMP error packet\r
	195	@param[in] Packet The content of the ICMP error with IP4 head\r
	196	removed.\r
	197	\r
	198	@retval EFI_OUT_OF_RESOURCES Failed to allocate resource.\r
	199	@retval EFI_SUCCESS The ICMP Echo request is successfully answered.\r
	200	@retval Others Failed to answer the ICMP echo request.\r
	201	\r
	202	**/\r
	203	EFI_STATUS\r
	204	Ip4IcmpReplyEcho (\r
	205	IN IP4_SERVICE *IpSb,\r
	206	IN IP4_HEAD *Head,\r
	207	IN NET_BUF *Packet\r
	208	)\r
	209	{\r
	210	IP4_ICMP_QUERY_HEAD *Icmp;\r
	211	NET_BUF *Data;\r
	212	EFI_STATUS Status;\r
	213	IP4_HEAD ReplyHead;\r
	214	\r
	215	//\r
	216	// make a copy the packet, it is really a bad idea to\r
	217	// send the MNP's buffer back to MNP.\r
	218	//\r
	219	Data = NetbufDuplicate (Packet, NULL, IP4_MAX_HEADLEN);\r
	220	\r
	221	if (Data == NULL) {\r
	222	Status = EFI_OUT_OF_RESOURCES;\r
	223	goto ON_EXIT;\r
	224	}\r
	225	\r
	226	//\r
	227	// Change the ICMP type to echo reply, exchange the source\r
	228	// and destination, then send it. The source is updated to\r
	229	// use specific destination. See RFC1122. SRR/RR option\r
	230	// update is omitted.\r
	231	//\r
	232	Icmp = (IP4_ICMP_QUERY_HEAD *)NetbufGetByte (Data, 0, NULL);\r
	233	ASSERT (Icmp != NULL);\r
	234	Icmp->Head.Type = ICMP_ECHO_REPLY;\r
	235	Icmp->Head.Checksum = 0;\r
	236	Icmp->Head.Checksum = (UINT16)(~NetblockChecksum ((UINT8 *)Icmp, Data->TotalSize));\r
	237	\r
	238	ReplyHead.Tos = 0;\r
	239	ReplyHead.Fragment = 0;\r
	240	ReplyHead.Ttl = 64;\r
	241	ReplyHead.Protocol = EFI_IP_PROTO_ICMP;\r
	242	ReplyHead.Src = 0;\r
	243	\r
	244	//\r
	245	// Ip4Output will select a source for us\r
	246	//\r
	247	ReplyHead.Dst = Head->Src;\r
	248	\r
	249	Status = Ip4Output (\r
	250	IpSb,\r
	251	NULL,\r
	252	Data,\r
	253	&ReplyHead,\r
	254	NULL,\r
	255	0,\r
	256	IP4_ALLZERO_ADDRESS,\r
	257	Ip4SysPacketSent,\r
	258	NULL\r
	259	);\r
	260	if (EFI_ERROR (Status)) {\r
	261	NetbufFree (Data);\r
	262	}\r
	263	\r
	264	ON_EXIT:\r
	265	NetbufFree (Packet);\r
	266	return Status;\r
	267	}\r
	268	\r
	269	/**\r
	270	Process the ICMP query message. If it is an ICMP echo\r
	271	request, answer it. Otherwise deliver it to upper layer.\r
	272	\r
	273	@param[in] IpSb The IP4 service that receivd the packet\r
	274	@param[in] Head The IP4 head of the ICMP query packet\r
	275	@param[in] Packet The content of the ICMP query with IP4 head\r
	276	removed.\r
	277	\r
	278	@retval EFI_INVALID_PARAMETER The packet is invalid\r
	279	@retval EFI_SUCCESS The ICMP query message is processed\r
	280	@retval Others Failed to process ICMP query.\r
	281	\r
	282	**/\r
	283	EFI_STATUS\r
	284	Ip4ProcessIcmpQuery (\r
	285	IN IP4_SERVICE *IpSb,\r
	286	IN IP4_HEAD *Head,\r
	287	IN NET_BUF *Packet\r
	288	)\r
	289	{\r
	290	IP4_ICMP_QUERY_HEAD Icmp;\r
	291	\r
	292	if (Packet->TotalSize < sizeof (Icmp)) {\r
	293	NetbufFree (Packet);\r
	294	return EFI_INVALID_PARAMETER;\r
	295	}\r
	296	\r
	297	NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *)&Icmp);\r
	298	\r
	299	if (Icmp.Head.Type == ICMP_ECHO_REQUEST) {\r
	300	return Ip4IcmpReplyEcho (IpSb, Head, Packet);\r
	301	}\r
	302	\r
	303	return Ip4Demultiplex (IpSb, Head, Packet, NULL, 0);\r
	304	}\r
	305	\r
	306	/**\r
	307	Handle the ICMP packet. First validate the message format,\r
	308	then according to the message types, process it as query or\r
	309	error packet.\r
	310	\r
	311	@param[in] IpSb The IP4 service that receivd the packet.\r
	312	@param[in] Head The IP4 head of the ICMP query packet.\r
	313	@param[in] Packet The content of the ICMP query with IP4 head\r
	314	removed.\r
	315	\r
	316	@retval EFI_INVALID_PARAMETER The packet is malformatted.\r
	317	@retval EFI_SUCCESS The ICMP message is successfully processed.\r
	318	@retval Others Failed to handle ICMP packet.\r
	319	\r
	320	**/\r
	321	EFI_STATUS\r
	322	Ip4IcmpHandle (\r
	323	IN IP4_SERVICE *IpSb,\r
	324	IN IP4_HEAD *Head,\r
	325	IN NET_BUF *Packet\r
	326	)\r
	327	{\r
	328	IP4_ICMP_HEAD Icmp;\r
	329	UINT16 Checksum;\r
	330	\r
	331	if (Packet->TotalSize < sizeof (Icmp)) {\r
	332	goto DROP;\r
	333	}\r
	334	\r
	335	NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *)&Icmp);\r
	336	\r
	337	if (Icmp.Type > ICMP_TYPE_MAX) {\r
	338	goto DROP;\r
	339	}\r
	340	\r
	341	Checksum = (UINT16)(~NetbufChecksum (Packet));\r
	342	if ((Icmp.Checksum != 0) && (Checksum != 0)) {\r
	343	goto DROP;\r
	344	}\r
	345	\r
	346	if (mIcmpClass[Icmp.Type].IcmpClass == ICMP_ERROR_MESSAGE) {\r
	347	return Ip4ProcessIcmpError (IpSb, Head, Packet);\r
	348	} else if (mIcmpClass[Icmp.Type].IcmpClass == ICMP_QUERY_MESSAGE) {\r
	349	return Ip4ProcessIcmpQuery (IpSb, Head, Packet);\r
	350	}\r
	351	\r
	352	DROP:\r
	353	NetbufFree (Packet);\r
	354	return EFI_INVALID_PARAMETER;\r
	355	}\r