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Frequency_Inverter/Firmware/Inverter_firmware/rtcs/source/tcpip/icmp.c
Indemsys db9ab280ef Initial commit
2022-01-04 12:22:53 +02:00

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/**HEADER********************************************************************
*
* Copyright (c) 2008 Freescale Semiconductor;
* All Rights Reserved
*
* Copyright (c) 2004-2008 Embedded Access Inc.;
* All Rights Reserved
*
* Copyright (c) 1989-2008 ARC International;
* All Rights Reserved
*
***************************************************************************
*
* THIS SOFTWARE IS PROVIDED BY FREESCALE "AS IS" AND ANY EXPRESSED 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 FREESCALE OR ITS 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.
*
**************************************************************************
*
* $FileName: icmp.c$
* $Version : 3.8.14.0$
* $Date : Jun-14-2012$
*
* Comments:
*
* This file contains the implementation of a minimal
* Internet Control Message Protocol. For more details,
* refer to RFC792.
*
*END************************************************************************/
#include <rtcs.h>
#include "rtcs_prv.h"
#include "tcpip.h"
#include "icmp_prv.h"
#include "tcp_prv.h"
#include "udp_prv.h"
#if RTCSCFG_ENABLE_ICMP && RTCSCFG_ENABLE_IP4
/*FUNCTION*-------------------------------------------------------------
*
* Function Name : ICMP_init
* Returned Values : uint_32
* Comments :
* Initialize the ICMP layer.
*
*END*-----------------------------------------------------------------*/
uint_32 ICMP_init
(
void
)
{ /* Body */
ICMP_CFG_STRUCT_PTR icmp_cfg_ptr;
uint_32 status = RTCS_OK; /* return code */
icmp_cfg_ptr = RTCS_mem_alloc_zero(sizeof(ICMP_CFG_STRUCT));
if (icmp_cfg_ptr == NULL) {
return RTCSERR_OUT_OF_MEMORY;
} /* Endif */
_mem_set_type(icmp_cfg_ptr, MEM_TYPE_ICMP_CFG_STRUCT);
RTCS_setcfg(ICMP, icmp_cfg_ptr);
IP_open(IPPROTO_ICMP, ICMP_service, NULL, &status);
return status;
} /* Endbody */
/*FUNCTION*-------------------------------------------------------------
*
* Function Name : ICMP_service
* Returned Values : void
* Comments :
* Process incoming ICMP packets. Called from IP_service.
*
*END*-----------------------------------------------------------------*/
void ICMP_service
(
RTCSPCB_PTR pcb, /* [IN/OUT] incoming packet */
pointer dummy /* [IN] not used */
)
{ /* Body */
ICMP_CFG_STRUCT_PTR ICMP_cfg_ptr;
ICMP_HEADER_PTR packet;
_ip_address source, dest;
uint_32 error;
uint_16 chksum;
uchar type;
ICMP_cfg_ptr = RTCS_getcfg(ICMP);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_TOTAL++);
packet = (ICMP_HEADER_PTR)RTCSPCB_DATA(pcb);
source = IP_source(pcb);
dest = IP_dest(pcb);
type = ntohc(packet->TYPE);
/*
** Make sure that
** sizeof(ICMP_HEADER) <= RTCSPCB_SIZE(pcb)
*/
if (RTCSPCB_SIZE(pcb) < sizeof(ICMP_HEADER)) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_RX_SMALL_DGRAM++);
RTCSLOG_PCB_FREE(pcb, RTCSERR_ICMP_BAD_HEADER);
RTCSPCB_free(pcb);
return;
} /* Endif */
/*
** Verify the checksum
*/
if (IP_Sum_PCB(0, pcb) != 0xFFFF) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_RX_BAD_CHECKSUM++);
RTCSLOG_PCB_FREE(pcb, RTCSERR_ICMP_BAD_CHECKSUM);
RTCSPCB_free(pcb);
return;
} /* Endif */
RTCSLOG_PCB_READ(pcb, RTCS_LOGCTRL_PROTO(IPPROTO_ICMP), 0);
switch (type) {
case ICMPTYPE_REDIRECT:
#if RTCSCFG_ENABLE_GATEWAYS
{ /* Scope */
_ip_address origdest, gateway;
ICMP_ERR_HEADER_PTR rdpacket = (ICMP_ERR_HEADER_PTR)packet;
IPIF_PARM parms;
/*
** Make sure that
** sizeof(ICMP_ERR_HEADER) <= RTCSPCB_SIZE(pcb)
*/
if (RTCSPCB_SIZE(pcb) < sizeof(ICMP_ERR_HEADER)) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_RX_SMALL_DGRAM++);
RTCSLOG_PCB_FREE(pcb, RTCSERR_ICMP_BAD_HEADER);
RTCSPCB_free(pcb);
return;
} /* Endif */
gateway = ntohl(rdpacket->DATA);
origdest = ntohl(rdpacket->IP.DEST);
// If we receive a redirect to ourselves, silently discard it
if (IP_is_local(NULL, gateway)) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
// Might want to add a counter here
} else if (IP_is_gate(source, origdest)) {
parms.address = gateway;
parms.network = origdest;
parms.netmask = 0xFFFFFFFFL;
parms.locmask = 0;
RTCSCMD_internal(parms, IPIF_gate_add_redirect);
} else {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_RX_RD_NOTGATE++);
} /* Endif */
} /* Endscope */
#else
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
#endif
break;
case ICMPTYPE_ECHO_REQ:
error = RTCSPCB_next(pcb, sizeof(ICMP_HEADER));
if (error) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_ERRORS++);
IF_ICMP_STATS_ENABLED(RTCS_seterror(&ICMP_cfg_ptr->STATS.ERR_RX, error, (uint_32)pcb));
RTCSLOG_PCB_FREE(pcb, error);
RTCSPCB_free(pcb);
return;
} /* Endif */
/*
** RTCSPCB_fork() failing isn't a serious error, so we don't check
** the error code
*/
RTCSPCB_fork(pcb);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_TX_TOTAL++);
RTCSLOG_PCB_WRITE(pcb, RTCS_LOGCTRL_PROTO(IPPROTO_ICMP), 0);
error = RTCSPCB_insert_header(pcb, sizeof(ICMP_HEADER));
if (error) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_RX_ECHO_REQ++);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_TX_MISSED++);
IF_ICMP_STATS_ENABLED(RTCS_seterror(&ICMP_cfg_ptr->STATS.ERR_TX, error, (uint_32)pcb));
RTCSLOG_PCB_FREE(pcb, error);
RTCSPCB_free(pcb);
return;
} /* Endif */
/* Change type from Echo to Echo Reply and recalculate checksum */
packet = (ICMP_HEADER_PTR)RTCSPCB_DATA(pcb);
htonc(packet->TYPE, ICMPTYPE_ECHO_REPLY);
htonc(packet->CODE, 0);
htons(packet->CHECKSUM, 0);
chksum = IP_Sum_PCB(0, pcb);
chksum = IP_Sum_invert(chksum);
htons(packet->CHECKSUM, chksum);
pcb->IP_SUM_PTR = NULL;
/* Send the Echo Reply whence came the Echo */
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_TX_ECHO_REPLY++);
IP_send(pcb, IPPROTO_ICMP, dest, source, 0);
pcb = NULL;
break;
case ICMPTYPE_ECHO_REPLY:
{ /* Scope */
ICMP_ECHO_HEADER_PTR echopacket = (ICMP_ECHO_HEADER_PTR)packet;
ICMP_PARM_PTR parms;
uint_16 id, seq;
/*
** Make sure that
** sizeof(ICMP_ECHO_HEADER) <= RTCSPCB_SIZE(pcb)
*/
if (RTCSPCB_SIZE(pcb) < sizeof(ICMP_ECHO_HEADER)) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++);
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.ST_RX_SMALL_DGRAM++);
RTCSLOG_PCB_FREE(pcb, RTCSERR_ICMP_BAD_HEADER);
RTCSPCB_free(pcb);
return;
} /* Endif */
/*
** get the ID and Sequence number from the packet
*/
id = ntohs(echopacket->ID);
seq = ntohs(echopacket->SEQ);
/*
** Find a match for the ID and sequence number
*/
for (parms=ICMP_cfg_ptr->ECHO_PARM_HEAD; parms; parms=parms->NEXT) {
if ((parms->id == id) && (parms->seq == seq)) {
/* received reply for the ping request */
if (parms->NEXT) {
parms->NEXT->PREV = parms->PREV;
} /* Endif */
*parms->PREV = parms->NEXT;
TCPIP_Event_cancel(&parms->EXPIRE);
/* calculate round trip time */
parms->timeout = RTCS_timer_get_interval(parms->timeout, RTCS_time_get());
RTCSCMD_complete(parms, RTCS_OK);
break;
} /* Endif */
} /* Endfor */
} /* Endscope */
break;
case ICMPTYPE_DESTUNREACH:
case ICMPTYPE_TIMEEXCEED:
{ /* Scope */
IP_HEADER_PTR ip;
ICMP_ERR_HEADER_PTR icmp_err = (ICMP_ERR_HEADER_PTR)packet;
uint_32 len, remain;
boolean discard = TRUE;
uchar code;
/*
** Check if the attached IP header is IP over IP, and if so, strip IP
** headers until we find one whose source address is not local. Then we
** forward the ICMP error to that IP address
*/
remain = RTCSPCB_SIZE(pcb);
/* Make sure we have at least a full IP header */
if (remain >= sizeof(ICMP_HEADER) + 4 + sizeof(IP_HEADER)) {
ip = (IP_HEADER_PTR)((uchar_ptr)packet + sizeof(ICMP_HEADER) + 4);
remain -= sizeof(ICMP_HEADER) + 4;
do {
/* Make sure the IP header is IP over IP */
if (ntohc(ip->PROTOCOL) != IPPROTO_IPIP) {
break;
} /* Endif */
/* Make sure we have a full IP header + 8 bytes */
len = (ntohc(ip->VERSLEN) & 0x0F) << 2;
if (remain < len + sizeof(IP_HEADER)) {
break;
} /* Endif */
/* Get next header */
ip = (IP_HEADER_PTR)((uchar_ptr)(ip) + len);
remain -= len;
source = ntohl(ip->SOURCE);
discard = IP_is_local(NULL, source);
} while(discard);
len = (ntohc(ip->VERSLEN) & 0x0F) << 2;
/*
** discard is true if we are the originator of the IP packet
** in error, or if there was not enough information to find the
** originator. We make sure discard is false, and there is at
** least a full IP header + 8 bytes of data left
*/
if (!discard && (len + 8 <= remain)) {
if (type == ICMPTYPE_DESTUNREACH) {
code = ntohc(packet->CODE);
switch (code) {
case ICMPCODE_DU_PROTO_UNREACH:
/*
** If we are sending back to the originator, and the
** originator did not use IP over IP, the protocol
** unreachable error is useless.
*/
code = ICMPCODE_DU_NET_UNREACH;
break;
case ICMPCODE_DU_PORT_UNREACH:
/* It doesn't make sense to receive this */
discard = TRUE;
break;
case ICMPCODE_DU_SRCROUTE:
discard = TRUE;
break;
} /* Endswitch */
} else {
/*
** Type is ICMPTYPE_TIMEEXCEED
**
** Problem with routing loops within tunnel. Originator
** does not need to know about tunnel.
*/
type = ICMPTYPE_DESTUNREACH;
code = ICMPCODE_DU_HOST_UNREACH;
} /* Endif */
if (!discard) {
ICMP_send_error_internal(type, code, ntohl(icmp_err->DATA),
ip, NULL, remain);
} /* Endif */
} /* Endif */
} /* Endif */
} /* Endscope */
break;
} /* End Switch */
#if RTCSCFG_ENABLE_ICMP_STATS
/* Update the statistics */
switch (type) {
case ICMPTYPE_DESTUNREACH: ICMP_cfg_ptr->STATS.ST_RX_DESTUNREACH++; break;
case ICMPTYPE_TIMEEXCEED: ICMP_cfg_ptr->STATS.ST_RX_TIMEEXCEED++; break;
case ICMPTYPE_PARMPROB: ICMP_cfg_ptr->STATS.ST_RX_PARMPROB++; break;
case ICMPTYPE_SRCQUENCH: ICMP_cfg_ptr->STATS.ST_RX_SRCQUENCH++; break;
case ICMPTYPE_REDIRECT: ICMP_cfg_ptr->STATS.ST_RX_REDIRECT++; break;
case ICMPTYPE_ECHO_REQ: ICMP_cfg_ptr->STATS.ST_RX_ECHO_REQ++; break;
case ICMPTYPE_ECHO_REPLY: ICMP_cfg_ptr->STATS.ST_RX_ECHO_REPLY++; break;
case ICMPTYPE_TIME_REQ: ICMP_cfg_ptr->STATS.ST_RX_TIME_REQ++; break;
case ICMPTYPE_TIME_REPLY: ICMP_cfg_ptr->STATS.ST_RX_TIME_REPLY++; break;
case ICMPTYPE_INFO_REQ: ICMP_cfg_ptr->STATS.ST_RX_INFO_REQ++; break;
case ICMPTYPE_INFO_REPLY: ICMP_cfg_ptr->STATS.ST_RX_INFO_REPLY++; break;
default:
ICMP_cfg_ptr->STATS.ST_RX_OTHER++;
ICMP_cfg_ptr->STATS.COMMON.ST_RX_DISCARDED++;
break;
} /* Endswitch */
#endif
if (pcb) {
RTCSLOG_PCB_FREE(pcb, RTCS_OK);
RTCSPCB_free(pcb);
} /* Endif */
} /* Endbody */
/*FUNCTION*-------------------------------------------------------------
*
* Function Name : ICMP_send_error_internal
* Returned Values : void
* Comments :
* Send a ICMP error with the IP header that produced it.
*
* Warning :
* This packet assumes that the IP header is correct,
* i.e. IP must not use this function on packets recorded
* in ST_RX_HDR_ERRORS.
*
*END*-----------------------------------------------------------------*/
void ICMP_send_error_internal
(
uint_8 type, /* [IN] the type to send */
uint_8 code, /* [IN] the code to send */
uint_32 param, /* [IN] a parameter */
IP_HEADER_PTR iph, /* [IN] the IP header */
RTCSPCB_PTR origpcb, /* [IN] pcb with bad packet */
uint_32 maxlen /* [IN] the max data len to send, 0 = default */
)
{ /* Body */
ICMP_CFG_STRUCT_PTR ICMP_cfg_ptr = RTCS_getcfg(ICMP);
RTCSPCB_PTR pcb;
ICMP_ERR_HEADER_PTR icmph;
_ip_address ipsrc = ntohl(iph->SOURCE);
_ip_address ipdst = ntohl(iph->DEST);
uint_16 iphdrlen = (ntohc(iph->VERSLEN) & 0x0F) << 2;
uint_16 ippktlen = ntohs(iph->LENGTH) - iphdrlen;
uint_16 checksum;
_ip_address icmpsrc = IP_is_local(NULL,ipdst) ? ipdst : INADDR_ANY;
uint_32 error;
uchar_ptr buffer;
uint_32 temp;
#if RTCSCFG_ENABLE_NAT
TCP_HEADER_PTR tcp_hdr;
UDP_HEADER_PTR udp_hdr;
IP_HEADER_PTR ip_hdr;
uint_32 protocol;
uint_16 src_port, dest_port;
uint_32 (_CODE_PTR_ _PTR_ nat_exec)(RTCSPCB_PTR _PTR_);
#endif
/*
** Only include up to a maximum of maxlen bytes of data from the
** original IP datagram
*/
if (!maxlen) {
maxlen = IP_DEFAULT_MTU - sizeof(IP_HEADER) - sizeof(ICMP_HEADER) - 4;
} /* Endif */
if (origpcb) {
temp = RTCSPCB_DATA(origpcb) - RTCSPCB_DATA_NETWORK(origpcb);
if (maxlen > origpcb->HEADER_FRAG_USED + temp) {
maxlen = origpcb->HEADER_FRAG_USED + temp;
} /* Endif */
} /* Endif */
if (ippktlen + iphdrlen > maxlen) {
ippktlen = maxlen - iphdrlen;
} /* Endif */
/* Don't send an error in response to an ICMP error */
if (ntohc(iph->PROTOCOL) == IPPROTO_ICMP) {
/* Make sure the packet has at least a 'TYPE' field */
if (ippktlen == 0) {
return;
} /* Endif */
icmph = (ICMP_ERR_HEADER_PTR)((uchar_ptr)iph + iphdrlen);
if (!ICMPTYPE_ISQUERY(ntohc(icmph->HEAD.TYPE))) {
return;
} /* Endif */
} /* Endif */
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_TX_TOTAL++);
/* Allocate a PCB */
pcb = RTCSPCB_alloc_send();
if (pcb == NULL) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_TX_MISSED++);
return;
} /* Endif */
//RTCSLOG_PCB_ALLOC(pcb);
if (origpcb) {
/* Add a dependency and a pointer to the ICMP data */
RTCSPCB_depend(pcb, origpcb);
error = RTCSPCB_append_fragment(pcb, iphdrlen + ippktlen, (uchar_ptr)iph);
} else {
/* Reserve space for the ICMP data */
buffer = RTCS_mem_alloc_system(iphdrlen + ippktlen);
if (!buffer) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_TX_MISSED++);
IF_ICMP_STATS_ENABLED(RTCS_seterror(&ICMP_cfg_ptr->STATS.ERR_TX, RTCSERR_OUT_OF_MEMORY, (uint_32)pcb));
RTCSLOG_PCB_FREE(pcb, RTCSERR_OUT_OF_MEMORY);
RTCSPCB_free(pcb);
return;
} /* Endif */
_mem_set_type(buffer, MEM_TYPE_ICMP_DATA);
_mem_copy(iph, buffer, iphdrlen + ippktlen);
error = RTCSPCB_append_fragment_autofree(pcb, iphdrlen + ippktlen, buffer);
if (error) {
_mem_free(buffer);
} /* Endif */
} /* Endif */
if (!error) {
error = RTCSPCB_insert_header(pcb, sizeof(ICMP_HEADER) + 4);
} /* Endif */
if (error) {
IF_ICMP_STATS_ENABLED(ICMP_cfg_ptr->STATS.COMMON.ST_TX_MISSED++);
IF_ICMP_STATS_ENABLED(RTCS_seterror(&ICMP_cfg_ptr->STATS.ERR_TX, error, (uint_32)pcb));
RTCSLOG_PCB_FREE(pcb, error);
RTCSPCB_free(pcb);
return;
} /* Endif */
RTCSLOG_PCB_WRITE(pcb, RTCS_LOGCTRL_PROTO(IPPROTO_ICMP), 0);
/* Build the header */
icmph = (ICMP_ERR_HEADER_PTR)RTCSPCB_DATA(pcb);
htonc(icmph->HEAD.TYPE, type);
htonc(icmph->HEAD.CODE, code);
htons(icmph->HEAD.CHECKSUM, 0);
htonl(icmph->DATA, param);
checksum = IP_Sum_PCB (0, pcb);
checksum = IP_Sum_invert(checksum);
htons(icmph->HEAD.CHECKSUM, checksum);
#if RTCSCFG_ENABLE_ICMP_STATS
/* Update the statistics */
switch (type) {
case ICMPTYPE_DESTUNREACH: ICMP_cfg_ptr->STATS.ST_TX_DESTUNREACH++; break;
case ICMPTYPE_TIMEEXCEED: ICMP_cfg_ptr->STATS.ST_TX_TIMEEXCEED++; break;
case ICMPTYPE_PARMPROB: ICMP_cfg_ptr->STATS.ST_TX_PARMPROB++; break;
case ICMPTYPE_SRCQUENCH: ICMP_cfg_ptr->STATS.ST_TX_SRCQUENCH++; break;
case ICMPTYPE_REDIRECT: ICMP_cfg_ptr->STATS.ST_TX_REDIRECT++; break;
case ICMPTYPE_ECHO_REQ: ICMP_cfg_ptr->STATS.ST_TX_ECHO_REQ++; break;
case ICMPTYPE_ECHO_REPLY: ICMP_cfg_ptr->STATS.ST_TX_ECHO_REPLY++; break;
case ICMPTYPE_TIME_REQ: ICMP_cfg_ptr->STATS.ST_TX_TIME_REQ++; break;
case ICMPTYPE_TIME_REPLY: ICMP_cfg_ptr->STATS.ST_TX_TIME_REPLY++; break;
case ICMPTYPE_INFO_REQ: ICMP_cfg_ptr->STATS.ST_TX_INFO_REQ++; break;
case ICMPTYPE_INFO_REPLY: ICMP_cfg_ptr->STATS.ST_TX_INFO_REPLY++; break;
default: ICMP_cfg_ptr->STATS.ST_TX_OTHER++; break;
} /* Endswitch */
#endif
#if RTCSCFG_ENABLE_NAT
/* Reverse NAT (if it is installed) on the origpcb,
otherwise the icmp error will not get sent to the
original src */
nat_exec = RTCS_getcfg(NAT);
if (origpcb && nat_exec && *nat_exec) {
// swap src and dst IPs and ports so NAT_apply
// will process the pcb
ip_hdr = (IP_HEADER_PTR)RTCSPCB_DATA(origpcb);
protocol = ntohc(ip_hdr->PROTOCOL);
// Swap ports if it is udp or tcp
if ((protocol == IPPROTO_TCP) || (protocol == IPPROTO_UDP)) {
switch(protocol)
{
case IPPROTO_TCP:
tcp_hdr = (TCP_HEADER_PTR)((uchar_ptr)ip_hdr + IPH_LEN(ip_hdr));
dest_port = ntohs(tcp_hdr->dest_port);
src_port = ntohs(tcp_hdr->source_port);
htons(tcp_hdr->dest_port, src_port);
htons(tcp_hdr->source_port, dest_port);
break;
case IPPROTO_UDP:
udp_hdr = (UDP_HEADER_PTR)((uchar_ptr)ip_hdr + IPH_LEN(ip_hdr));
dest_port = ntohs(udp_hdr->DEST_PORT);
src_port = ntohs(udp_hdr->SRC_PORT);
htons(udp_hdr->DEST_PORT, src_port);
htons(udp_hdr->SRC_PORT, dest_port);
break;
default:
// should not get here
break;
}
}
// swap IPs
ipsrc = ntohl(ip_hdr->SOURCE);
ipdst = ntohl(ip_hdr->DEST);
htonl(ip_hdr->SOURCE, ipdst);
htonl(ip_hdr->DEST,ipsrc);
// call NAT
error = (*nat_exec)(&origpcb);
if (!error) {
// swap IPs and ports back
ip_hdr = (IP_HEADER_PTR)RTCSPCB_DATA(origpcb);
protocol = ntohc(ip_hdr->PROTOCOL);
// swap ports if it is udp or tcp
if ((protocol == IPPROTO_TCP) || (protocol == IPPROTO_UDP)) {
switch(protocol)
{
case IPPROTO_TCP:
tcp_hdr = (TCP_HEADER_PTR)((uchar_ptr)ip_hdr + IPH_LEN(ip_hdr));
dest_port = ntohs(tcp_hdr->dest_port);
src_port = ntohs(tcp_hdr->source_port);
htons(tcp_hdr->dest_port, src_port);
htons(tcp_hdr->source_port, dest_port);
break;
case IPPROTO_UDP:
udp_hdr = (UDP_HEADER_PTR)((uchar_ptr)ip_hdr + IPH_LEN(ip_hdr));
dest_port = ntohs(udp_hdr->DEST_PORT);
src_port = ntohs(udp_hdr->SRC_PORT);
htons(udp_hdr->DEST_PORT, src_port);
htons(udp_hdr->SRC_PORT, dest_port);
break;
default:
// should not get here
break;
}
}
// swap IPs
ipsrc = ntohl(ip_hdr->SOURCE);
ipdst = ntohl(ip_hdr->DEST);
htonl(ip_hdr->SOURCE, ipdst);
htonl(ip_hdr->DEST,ipsrc);
// Recalculate the cksum
htons(icmph->HEAD.CHECKSUM, 0);
checksum = IP_Sum_PCB (0, pcb);
checksum = IP_Sum_invert(checksum);
htons(icmph->HEAD.CHECKSUM, checksum);
// recalculate icmpsrc, and use new ipsrc.
ipdst = ntohl(ip_hdr->DEST);
ipsrc = ntohl(ip_hdr->SOURCE);
icmpsrc = IP_is_local(NULL,ipdst) ? ipdst : INADDR_ANY;
}
}
#endif
/* Send it */
IP_send(pcb, IPPROTO_ICMP, icmpsrc, ipsrc, 0);
} /* Endbody */
/*FUNCTION*-------------------------------------------------------------
*
* Function Name : ICMP_send_error
* Returned Values : void
* Comments :
* Send a ICMP error with the IP header that produced it.
*
* Warning :
* This packet assumes that the IP header is correct,
* i.e. IP must not use this function on packets recorded
* in ST_RX_HDR_ERRORS.
*
*END*-----------------------------------------------------------------*/
void ICMP_send_error
(
uint_8 type, /* [IN] the type to send */
uint_8 code, /* [IN] the code to send */
uint_32 param, /* [IN] a parameter */
RTCSPCB_PTR inpcb, /* [IN] the packet which caused the error */
int_32 layer /* [IN] IP layer, relative to current */
)
{ /* Body */
IP_HEADER_PTR iph = (IP_HEADER_PTR)RTCSPCB_DATA_NETWORK(inpcb);
/* Don't send an error in response to a broadcast packet */
if (inpcb->TYPE & RTCSPCB_TYPE_BROADCAST) {
return;
} /* Endif */
ICMP_send_error_internal(type, code, param, iph, inpcb, 0);
} /* Endbody */
#endif /* RTCSCFG_ENABLE_ICMP && RTCSCFG_ENABLE_IP4 */
/* EOF */
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