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/*
*---------------------------------------------------------------------------
* cnat_v4_funtions.c
*
* Copyright (c) 2008-2013 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*---------------------------------------------------------------------------
*/
#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/pg/pg.h>
#include <vppinfra/error.h>
#include "tcp_header_definitions.h"
#include "cnat_db.h"
#include "cnat_config.h"
#include "cnat_v4_functions.h"
#include "dslite_defs.h"
#include "dslite_db.h"
static u32 tcp_logging_count;
static u32 tcp_logging_overflow;
static tcp_logging_struct_t tcp_logging_array[MAX_TCP_LOGGING_COUNT];
/*
* Function to log TCP pkts checksum changes..
*/
void
tcp_debug_logging (
u32 seq_num,
u32 ack_num,
u32 old_ip,
u32 new_ip,
u16 old_port,
u16 new_port,
u16 old_ip_crc,
u16 new_ip_crc,
u16 old_tcp_crc,
u16 new_tcp_crc)
{
tcp_logging_array[tcp_logging_count].seq_num = seq_num;
tcp_logging_array[tcp_logging_count].ack_num = ack_num;
tcp_logging_array[tcp_logging_count].old_ip = old_ip;
tcp_logging_array[tcp_logging_count].new_ip = new_ip;
tcp_logging_array[tcp_logging_count].old_port = old_port;
tcp_logging_array[tcp_logging_count].new_port = new_port;
tcp_logging_array[tcp_logging_count].old_ip_crc = old_ip_crc;
tcp_logging_array[tcp_logging_count].new_ip_crc = new_ip_crc;
tcp_logging_array[tcp_logging_count].old_tcp_crc = old_tcp_crc;
tcp_logging_array[tcp_logging_count].new_tcp_crc = new_tcp_crc;
tcp_logging_count++;
if (tcp_logging_count >= MAX_TCP_LOGGING_COUNT) {
tcp_logging_overflow = 1;
tcp_logging_count = 0;
}
}
/*
* Function to dmp TCP pkts logged..
*/
void
tcp_debug_logging_dump (void)
{
u32 i, total_count, start_entry;
if (tcp_logging_overflow) {
total_count = MAX_TCP_LOGGING_COUNT;
start_entry = tcp_logging_count;
printf("Logging Entries Wrapped Around, displaying %d entries\n",
total_count);
} else {
total_count = tcp_logging_count;
start_entry = 0;
printf("Displaying %d entries\n", total_count);
}
printf("SEQ ACK IP_O IP_N PORT_O PORT_N L3_CRC_O L3_CRC_N L4_CRC_O L4_CRC_N\n");
for (i = 0; i < total_count; i++) {
u32 entry = (i + start_entry) % MAX_TCP_LOGGING_COUNT;
printf("%04d: 0x%08x 0x%08x 0x%08x 0x%08x 0x%04x 0x%04x 0x%04x 0x%04x 0x%04x 0x%04x\n",
entry,
tcp_logging_array[entry].seq_num,
tcp_logging_array[entry].ack_num,
tcp_logging_array[entry].old_ip,
tcp_logging_array[entry].new_ip,
tcp_logging_array[entry].old_port,
tcp_logging_array[entry].new_port,
tcp_logging_array[entry].old_ip_crc,
tcp_logging_array[entry].new_ip_crc,
tcp_logging_array[entry].old_tcp_crc,
tcp_logging_array[entry].new_tcp_crc);
}
}
/*
* Function to enable TCP logging
*/
void
tcp_debug_logging_enable_disable (u32 enable_flag)
{
switch (enable_flag) {
case TCP_LOGGING_DISABLE:
if (tcp_logging_enable_flag == TCP_LOGGING_DISABLE) {
printf("\nTCP Logging ALREADY DISABLED\n");
} else {
printf("\nTCP Logging DISABLED\n");
}
tcp_logging_enable_flag = 0;
break;
case TCP_LOGGING_ENABLE:
if (tcp_logging_enable_flag == TCP_LOGGING_ENABLE) {
printf("\nTCP Logging ALREADY ENABLED\n");
} else {
tcp_logging_enable_flag = 1;
tcp_logging_count = 0;
tcp_logging_overflow = 0;
printf("\nTCP Logging ENABLED\n");
}
break;
case TCP_LOGGING_PACKET_DUMP:
tcp_debug_logging_dump();
break;
case TCP_LOGGING_SUMMARY_DUMP:
default:
printf("\ntcp_logging_enable_flag %d, tcp_log_count %d\n",
tcp_logging_enable_flag, tcp_logging_count);
printf("To Enable TCP LOGGING provide a flag value of %d\n",
TCP_LOGGING_ENABLE);
break;
}
}
void hex_dump (u8 * p, int len) {
int i;
for (i=0;i<len;i++) {
if(i && (i & 0x3 ) == 0) printf(" ");
if(i && (i & 0xf ) == 0) printf("\n");
PLATFORM_DEBUG_PRINT("%02X ", p[i]);
}
PLATFORM_DEBUG_PRINT("\n");
}
void
print_icmp_pkt (ipv4_header *ip)
{
u32 i, total_len;
u8 *pkt = (u8 *) ip;
total_len = clib_net_to_host_u16(ip->total_len_bytes);
printf("\n======== PRINTING PKT START======\n");
printf("======== IP PACKET LEN %d ===========\n", total_len);
for (i=0; i < 20; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== ICMP HEADER =================\n");
for (i=20; i < 28; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== ICMP BODY ===================\n");
for (i=28; i < total_len; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== PRINTING PKT END =======\n");
}
void
print_udp_pkt (ipv4_header *ip)
{
u32 i, total_len, udp_len;
u8 *pkt = (u8 *) ip;
total_len = clib_net_to_host_u16(ip->total_len_bytes);
udp_len = total_len - 20;
printf("\n======== PRINTING PKT START======\n");
printf("======== IP PACKET LEN %d ===========\n", total_len);
for (i=0; i < 20; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== UDP PSEUDO HEADER ==========\n");
for (i=12; i < 20; i++) {
printf(" %02X ", *(pkt + i));
}
printf(" 00 11 %02X %02X ", udp_len >> 8, udp_len & 0xff);
printf("\n======== UDP HEADER =================\n");
for (i=20; i < 28; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== UDP BODY ===================\n");
for (i=28; i < total_len; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== PRINTING PKT END =======\n");
}
void
print_tcp_pkt (ipv4_header *ip)
{
u32 i, total_len, tcp_len;
u8 *pkt = (u8 *) ip;
total_len = clib_net_to_host_u16(ip->total_len_bytes);
tcp_len = total_len - 20;
printf("\n======== PRINTING PKT START======\n");
printf("======== IP PACKET LEN %d ===========\n", total_len);
for (i=0; i < 20; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== TCP PSEUDO HEADER ==========\n");
for (i=12; i < 20; i++) {
printf(" %02X ", *(pkt + i));
}
printf(" 00 06 %02X %02X ", tcp_len >> 8, tcp_len & 0xff);
printf("\n======== TCP HEADER =================\n");
for (i=20; i < 40; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== TCP BODY ===================\n");
for (i=40; i < total_len; i++) {
printf(" %02X ", *(pkt + i));
}
printf("\n======== PRINTING PKT END =======\n");
}
/* IN: ipv4 and tcp header pointer,
* new ipv4 addr and port value
* main db index for accessing per vrf mss value
* DO:
* NAT
* mss adjust if needed
* ip & tcp checksum update (incremental)
*/
inline void tcp_in2out_nat_mss_n_checksum (ipv4_header * ip,
tcp_hdr_type * tcp,
u32 ipv4_addr,
u16 port,
cnat_main_db_entry_t * db)
{
u8 *mss_ptr;
u8 check_mss = 0;
u16 mss_old, mss_new;
cnat_vrfmap_t * vrf_map_p;
cnat_v4_recalculate_tcp_checksum(ip,
tcp,
&(ip->src_addr),
&(tcp->src_port),
ipv4_addr,
port);
u16 frag_offset =
clib_net_to_host_u16(ip->frag_flags_offset);
if(PREDICT_FALSE(frag_offset & IP_FRAG_OFFSET_MASK)) {
return; /* No TCP Header at all */
}
/*
* check SYN bit and if options field is present
* If yes, proceed to extract the options and get TCP MSS value
*/
check_mss = ((tcp->flags & TCP_FLAG_SYN) &&
(((tcp->hdr_len>>4) << 2) > sizeof(tcp_hdr_type)));
if (PREDICT_FALSE(check_mss)) {
/* get per VRF mss config */
if(PREDICT_FALSE(db->flags & (CNAT_DB_DSLITE_FLAG))) {
mss_new = dslite_table_db_ptr[db->dslite_nat44_inst_id].tcp_mss;
} else {
vrf_map_p = cnat_map_by_vrf + db->vrfmap_index;
mss_new = vrf_map_p->tcp_mss;
}
DSLITE_PRINTF(1, "Check MSS true..%u\n", mss_new);
/*
* If TCP MSS is not configured, skip the MSS checks
*/
if (PREDICT_FALSE(mss_new != V4_TCP_MSS_NOT_CONFIGURED_VALUE)) {
/* if mss_ptr != NULL, then it points to MSS option */
mss_ptr = tcp_findoption(tcp, TCP_OPTION_MSS);
/*
* TCP option field: | kind 1B | len 1B | value 2B|
* where kind != [0,1]
*/
if (PREDICT_TRUE(mss_ptr && (mss_ptr[1] == 4))) {
u16 *ptr = (u16*)(mss_ptr + 2);
mss_old = clib_net_to_host_u16(*ptr);
if (PREDICT_FALSE(mss_old > mss_new)) {
u32 sum32;
u16 mss_old_r, old_tcp_checksum_r;
*ptr = clib_host_to_net_u16(mss_new);
mss_old_r = ~mss_old;
old_tcp_checksum_r =
~clib_net_to_host_u16(tcp->tcp_checksum);
/*
* Revise the TCP checksum
*/
sum32 = old_tcp_checksum_r + mss_old_r + mss_new;
FILL_CHECKSUM(tcp->tcp_checksum, sum32)
if (PREDICT_FALSE(tcp_logging_enable_flag)) {
tcp_debug_logging(
clib_net_to_host_u32(tcp->seq_num),
clib_net_to_host_u32(tcp->ack_num),
0,
0,
mss_old,
mss_new,
0,
0,
~old_tcp_checksum_r,
clib_net_to_host_u16(tcp->tcp_checksum));
}
}
}
}
}
}
u32 get_my_svi_intf_ip_addr() {
return 0x01010101;
}
|
