/*
*---------------------------------------------------------------------------
* cnat_ipv4_tcp_inside_input.c - cnat_ipv4_tcp_inside_input node pipeline
* stage functions
*
*
* Copyright (c) 2008-2014 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 <vppinfra/error.h>
#include <vnet/buffer.h>
#include "cnat_db.h"
#include "tcp_header_definitions.h"
#include "cnat_config.h"
#include "cnat_global.h"
#include "cnat_v4_functions.h"
#define foreach_cnat_ipv4_tcp_inside_input_error \
_(CNAT_V4_TCP_I2O_PKT_IN, "tcp i2o packets received") \
_(CNAT_V4_TCP_I2O_PKT_T, "tcp i2o packets natted") \
_(CNAT_V4_TCP_I2O_EXCEPTION, "packets to tcp i2o exception") \
_(CNAT_V4_TCP_I2O_TTL_GEN, "generated TTL expiry ICMP packets") \
_(CNAT_V4_TCP_I2O_TTL_GEN_DROP, "could not generate TTL expiry ICMP packets") \
_(CNAT_V4_TCP_I2O_SESSION_DROP, "could not generate session") \
_(CNAT_V4_UDP_I2O_FRAG_DROP, "non-first fragment drop")
typedef enum {
#define _(sym,str) sym,
foreach_cnat_ipv4_tcp_inside_input_error
#undef _
CNAT_IPV4_TCP_INSIDE_INPUT_N_ERROR,
} cnat_ipv4_tcp_inside_input_t;
static char * cnat_ipv4_tcp_inside_input_error_strings[] = {
#define _(sym,string) string,
foreach_cnat_ipv4_tcp_inside_input_error
#undef _
};
typedef struct {
u32 cached_next_index;
/* $$$$ add data here */
/* convenience variables */
vlib_main_t * vlib_main;
vnet_main_t * vnet_main;
} cnat_ipv4_tcp_inside_input_main_t;
typedef enum {
CNAT_V4_TCP_I2O_E,
CNAT_V4_TCP_I2O_T,
CNAT_V4_TCP_I2O_D,
CNAT_V4_TCP_I2O_NEXT,
} cnat_ipv4_tcp_inside_input_next_t;
#define CNAT_REWRITE_OUTPUT CNAT_V4_TCP_I2O_T
#define CNAT_V4_ICMP_GEN CNAT_V4_TCP_I2O_D
//#define CNAT_V4_TCP_I2O_E CNAT_V4_TCP_I2O_D //remove it once exception node is created
cnat_ipv4_tcp_inside_input_main_t cnat_ipv4_tcp_inside_input_main;
vlib_node_registration_t cnat_ipv4_tcp_inside_input_node;
#define NSTAGES 6
/*
* Use the generic buffer metadata + first line of packet data prefetch
* stage function from <api/pipeline.h>. This is usually a Good Idea.
*/
#define stage0 generic_stage0
static inline void
stage1(vlib_main_t * vm, vlib_node_runtime_t * node, u32 buffer_index)
{
u64 a, b, c;
u32 bucket;
u8 *prefetch_target;
//cnat_feature_data_t *fd = (cnat_feature_data_t *)ctx->feature_data;
vlib_buffer_t * b0 = vlib_get_buffer (vm, buffer_index);
ipv4_header *ip = vlib_buffer_get_current (b0);
u8 ipv4_hdr_len = (ip->version_hdr_len_words & 0xf) << 2;
tcp_hdr_type *tcp = (tcp_hdr_type *)((u8*)ip + ipv4_hdr_len);
u64 tmp = 0;
tmp = vnet_buffer(b0)->vcgn_uii.key.k.ipv4 =
clib_net_to_host_u32(ip->src_addr);
vnet_buffer(b0)->vcgn_uii.key.k.port =
clib_net_to_host_u16 (tcp->src_port);
tmp |= ((u64)vnet_buffer(b0)->vcgn_uii.key.k.port) << 32;
PLATFORM_CNAT_SET_RX_VRF(vnet_buffer(b0)->sw_if_index[VLIB_RX],
vnet_buffer(b0)->vcgn_uii.key.k.vrf,
CNAT_TCP)
tmp |= ((u64)vnet_buffer(b0)->vcgn_uii.key.k.vrf) << 48;
CNAT_V4_GET_HASH(tmp, bucket, CNAT_MAIN_HASH_MASK)
prefetch_target = (u8 *)(&cnat_in2out_hash[bucket]);
vnet_buffer(b0)->vcgn_uii.bucket = bucket;
/* Prefetch the hash bucket */
CLIB_PREFETCH(prefetch_target, CLIB_CACHE_LINE_BYTES, LOAD);
}
static inline void
stage2(vlib_main_t * vm, vlib_node_runtime_t * node, u32 buffer_index)
{ /* nothing */ }
#define SPP_LOG2_CACHE_LINE_BYTES 6
#define SPP_CACHE_LINE_BYTES (1 << SPP_LOG2_CACHE_LINE_BYTES)
static inline void
stage3(vlib_main_t * vm, vlib_node_runtime_t * node, u32 buffer_index)
{
vlib_buffer_t * b0 = vlib_get_buffer(vm, buffer_index);
uword prefetch_target0, prefetch_target1;
u32 bucket = vnet_buffer(b0)->vcgn_uii.bucket;
/* read the hash bucket */
u32 db_index = vnet_buffer(b0)->vcgn_uii.bucket
= cnat_in2out_hash[bucket].next;
if (PREDICT_TRUE(db_index != EMPTY)) {
/*
* Prefetch database keys. We save space by not cache-line
* aligning the DB entries. We don't want to waste LSU
* bandwidth prefetching stuff we won't need.
*/
prefetch_target0 = (uword)(cnat_main_db + db_index);
CLIB_PREFETCH((void*)prefetch_target0, CLIB_CACHE_LINE_BYTES, LOAD);
/* Just beyond DB key #2 */
prefetch_target1 = prefetch_target0 +
STRUCT_OFFSET_OF(cnat_main_db_entry_t, user_ports);
/* If the targets are in different lines, do the second prefetch */
if (PREDICT_FALSE((prefetch_target0 & ~(SPP_CACHE_LINE_BYTES-1)) !=
(prefetch_target1 & ~(SPP_CACHE_LINE_BYTES-1)))) {
CLIB_PREFETCH((void *)prefetch_target1, CLIB_CACHE_LINE_BYTES, LOAD);
}
}
}
static inline void
stage4(vlib_main_t * vm, vlib_node_runtime_t * node, u32 buffer_index)
{
cnat_main_db_entry_t *db;
vlib_buffer_t * b0 = vlib_get_buffer(vm, buffer_index);
u32 db_index = vnet_buffer(b0)->vcgn_uii.bucket;
/*
* Note: if the search already failed (empty bucket),
* the answer is already in the pipeline context structure
*/
if (PREDICT_TRUE(db_index != EMPTY)) {
/*
* Note: hash collisions suck. We can't easily prefetch around them.
* The first trip around the track will be fast. After that, maybe
* not so much...
*/
do {
db = cnat_main_db + db_index;
if (PREDICT_TRUE(db->in2out_key.key64 ==
vnet_buffer(b0)->vcgn_uii.key.key64)) {
break;
}
db_index = db->in2out_hash.next;
} while (db_index != EMPTY);
/* Stick the answer back into the pipeline context structure */
vnet_buffer(b0)->vcgn_uii.bucket = db_index;
}
}
static inline u32 last_stage (vlib_main_t *vm, vlib_node_runtime_t *node,
u32 bi)
{
vlib_buffer_t *b0 = vlib_get_buffer (vm, bi);
u32 db_index = vnet_buffer(b0)->vcgn_uii.bucket;
spp_ctx_t *ctx = (spp_ctx_t *) &vnet_buffer(b0)->vcgn_uii;
int disposition = CNAT_V4_TCP_I2O_T;
int counter = CNAT_V4_TCP_I2O_PKT_T;
ipv4_header *ip = (ipv4_header *)vlib_buffer_get_current(b0);
u8 ipv4_hdr_len = (ip->version_hdr_len_words & 0xf) << 2;
tcp_hdr_type *tcp = (tcp_hdr_type *)((u8*)ip + ipv4_hdr_len);
vlib_node_t *n = vlib_get_node (vm, cnat_ipv4_tcp_inside_input_node.index);
u32 node_counter_base_index = n->error_heap_index;
vlib_error_main_t * em = &vm->error_main;
cnat_session_entry_t *session_db = NULL;
cnat_main_db_entry_t *db = NULL;
cnat_key_t dest_info;
u32 window;
u8 scale;
INCREMENT_NODE_COUNTER(CNAT_V4_TCP_I2O_PKT_IN);
if (PLATFORM_HANDLE_TTL_DECREMENT) {
if (PREDICT_FALSE(ip->ttl <= 1)) {
/* Try to generate ICMP error msg, as TTL is <= 1 */
if (icmpv4_generate_with_throttling
(ctx, ip, ctx->ru.rx.uidb_index)) {
/* Generated ICMP */
disposition = CNAT_REWRITE_OUTPUT;
counter = CNAT_V4_TCP_I2O_TTL_GEN;
} else {
/* Could not generated ICMP - drop the packet */
disposition = CNAT_V4_TCP_I2O_D;
counter = CNAT_V4_TCP_I2O_TTL_GEN_DROP;
}
goto drop_pkt;
}
}
if (PREDICT_FALSE(db_index == EMPTY)) {
/* Deleted fragment code from here */
disposition = CNAT_V4_TCP_I2O_E;
counter = CNAT_V4_TCP_I2O_EXCEPTION;
} else {
db = cnat_main_db + db_index;
/* Handle destination sessions */
dest_info.k.port = clib_net_to_host_u16(tcp->dest_port);
dest_info.k.ipv4 = clib_net_to_host_u32(ip->dest_addr);
if(PREDICT_TRUE(!PLATFORM_DBL_SUPPORT)) {
/* No DBL support, so just update the destn and proceed */
db->dst_ipv4 = dest_info.k.ipv4;
db->dst_port = dest_info.k.port;
goto update_pkt;
}
if(PREDICT_FALSE(db->dst_ipv4 != dest_info.k.ipv4 ||
db->dst_port != dest_info.k.port)) {
if(PREDICT_TRUE(db->nsessions == 0)) {
/* Should be a static entry
* Note this session as the first session and log
*/
cnat_add_dest_n_log(db, &dest_info);
} else if(PREDICT_FALSE(db->nsessions == 1)) {
/* Destn is not same as in main db. Multiple session
* scenario
*/
dest_info.k.vrf = db->in2out_key.k.vrf;
session_db = cnat_handle_1to2_session(db, &dest_info);
if(PREDICT_FALSE(session_db == NULL)) {
disposition = CNAT_V4_TCP_I2O_D;
counter = CNAT_V4_TCP_I2O_SESSION_DROP;
goto drop_pkt;
}
} else { /* There are already multiple destinations */
dest_info.k.vrf = db->in2out_key.k.vrf;
/* If session already exists,
* cnat_create_session_db_entry will return the existing db
* else create a new db
* If could not create, return NULL
*/
session_db = cnat_create_session_db_entry(&dest_info,
db, TRUE);
if(PREDICT_FALSE(session_db == NULL)) {
disposition = CNAT_V4_TCP_I2O_D;
counter = CNAT_V4_TCP_I2O_SESSION_DROP;
goto drop_pkt;
}
}
if(PREDICT_TRUE(session_db != 0)) {
/* Have to repeat the window size check for new destinations */
window = (u32)clib_net_to_host_u16(tcp->window_size);
window = window << session_db->scale;
if(PREDICT_TRUE(!session_db->window)) {
calculate_window_scale(tcp, &scale);
session_db->scale = scale;
session_db->window = window;
} else if (PREDICT_FALSE(session_db->window <
window)) {
/* Update the db entry with window option from packet */
session_db->window = window;
} else {
/* Do nothing */
}
session_db->tcp_seq_num = clib_net_to_host_u32(tcp->seq_num);
session_db->ack_no = clib_net_to_host_u32(tcp->ack_num);
#if DEBUG > 1
printf("\n In2out SDB stages seq no = %u,"
" ack no = %u, window = %u\n",
session_db->tcp_seq_num,
session_db->ack_no,
session_db->window);
#endif
}
} else {
//Update the seq no and ack no for subsequent communication
//after connection establishment
//No need to update window here. Window is already updated
//during connection establishment
window = (u32)clib_net_to_host_u16(tcp->window_size);
window = window << db->scale;
if(PREDICT_FALSE(!ALG_ENABLED_DB(db))) {
//This check is done since proto_data is part of union in main
//db entry
db->proto_data.tcp_seq_chk.seq_no =
clib_net_to_host_u32(tcp->seq_num);
db->proto_data.tcp_seq_chk.ack_no =
clib_net_to_host_u32(tcp->ack_num);
}
if (PREDICT_FALSE(db->diff_window < window)) {
/* Update the db entry with window option from packet */
db->diff_window = window;
}
#if DEBUG > 1
printf("\n In2out MainDB seq no = %u,"
"\n ack no = %u\n",
db->proto_data.tcp_seq_chk.seq_no,
db->proto_data.tcp_seq_chk.ack_no);
printf("\n In2out MAINDB window = %u\n",
db->diff_window);
#endif
}
update_pkt:
counter = CNAT_V4_TCP_I2O_PKT_T;
disposition = CNAT_V4_TCP_I2O_T;
/* NO FRAGMENT & ALG HANDLING. DELETING THE CODE */
if (PLATFORM_HANDLE_TTL_DECREMENT) {
/*
* Decrement TTL and update IPv4 checksum
*/
ipv4_decr_ttl_n_calc_csum(ip);
}
tcp_in2out_nat_mss_n_checksum(ip,
tcp,
db->out2in_key.k.ipv4,
db->out2in_key.k.port,
db
/*, db->in2out_key.k.vrf */);
/* update transaltion counters */
db->in2out_pkts++;
in2out_forwarding_count++;
/* update the timer for good mode, or evil mode dst_ip match */
if(PREDICT_FALSE(session_db != NULL)) {
V4_TCP_UPDATE_SESSION_DB_FLAG(session_db, tcp);
CNAT_DB_TIMEOUT_RST(session_db);
} else {
V4_TCP_UPDATE_SESSION_FLAG(db, tcp);
CNAT_DB_TIMEOUT_RST(db);
}
}
drop_pkt:
em->counters[node_counter_base_index + counter] += 1;
return disposition;
}
#include <vnet/pipeline.h>
static uword cnat_ipv4_tcp_inside_input_node_fn (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
return dispatch_pipeline (vm, node, frame);
}
VLIB_REGISTER_NODE (cnat_ipv4_tcp_inside_input_node) = {
.function = cnat_ipv4_tcp_inside_input_node_fn,
.name = "vcgn-v4-tcp-i2o",
.vector_size = sizeof (u32),
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(cnat_ipv4_tcp_inside_input_error_strings),
.error_strings = cnat_ipv4_tcp_inside_input_error_strings,
.n_next_nodes = CNAT_V4_TCP_I2O_NEXT,
/* edit / add dispositions here */
.next_nodes = {
[CNAT_V4_TCP_I2O_E] = "vcgn-v4-tcp-i2o-e",
[CNAT_V4_TCP_I2O_T] = "ip4-input",
[CNAT_V4_TCP_I2O_D] = "error-drop",
},
};
clib_error_t *cnat_ipv4_tcp_inside_input_init (vlib_main_t *vm)
{
cnat_ipv4_tcp_inside_input_main_t * mp = &cnat_ipv4_tcp_inside_input_main;
mp->vlib_main = vm;
mp->vnet_main = vnet_get_main();
return 0;
}
VLIB_INIT_FUNCTION (cnat_ipv4_tcp_inside_input_init);