/*
*---------------------------------------------------------------------------
* cnat_ipv4_tcp_inside_input_exceptions.c -
* cnat_ipv4_tcp_inside_input_exceptions 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_exc_error \
_(CNAT_V4_TCP_I2O_E_T_PKT, "v4 tcp i2o-e transmit natted pkt") \
_(CNAT_V4_TCP_I2O_E_D_NON_SYN_PKT, "v4 tcp i2o-e non syn drop") \
_(CNAT_V4_TCP_I2O_E_D_INVALID_PKT, "v4 tcp i2o-e invalid pkt drop") \
_(CNAT_V4_TCP_I2O_E_DROP, "v4 tcp i2o-e drop") \
_(CNAT_V4_TCP_I2O_E_GEN_ICMP, "v4 tcp i2o-e gen icmp msg") \
_(CNAT_V4_TCP_I2O_E_D_NO_SESSION, "v4 tcp i2o-e no session db entry drop")
typedef enum {
#define _(sym,str) sym,
foreach_cnat_ipv4_tcp_inside_input_exc_error
#undef _
CNAT_IPV4_TCP_INSIDE_INPUT_EXCEPTIONS_N_ERROR,
} cnat_ipv4_tcp_inside_input_exc_error_t;
static char * cnat_ipv4_tcp_inside_input_exc_error_strings[] = {
#define _(sym,string) string,
foreach_cnat_ipv4_tcp_inside_input_exc_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_exc_main_t;
typedef enum {
CNAT_V4_TCP_I2O_E_T,
//CNAT_V4_TCP_I2O_E_ICMP,
CNAT_V4_TCP_I2O_E_D,
CNAT_V4_TCP_I2O_E_NEXT,
} cnat_ipv4_udp_inside_input_exc_next_t;
#define CNAT_V4_TCP_I2O_E_ICMP CNAT_V4_TCP_I2O_E_D
cnat_ipv4_tcp_inside_input_exc_main_t cnat_ipv4_tcp_inside_input_exc_main;
vlib_node_registration_t cnat_ipv4_tcp_inside_input_exc_node;
#define NSTAGES 2
/*
* 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 u32 last_stage (vlib_main_t *vm, vlib_node_runtime_t *node,
u32 bi)
{
vlib_buffer_t *b0 = vlib_get_buffer (vm, bi);
vlib_node_t *n =
vlib_get_node (vm, cnat_ipv4_tcp_inside_input_exc_node.index);
u32 node_counter_base_index = n->error_heap_index;
vlib_error_main_t * em = &vm->error_main;
cnat_gen_icmp_info info;
cnat_db_key_bucket_t ki;
cnat_main_db_entry_t *db = NULL;
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);
int disposition = CNAT_V4_TCP_I2O_E_T;
int counter = CNAT_V4_TCP_I2O_E_T_PKT;
cnat_key_t dest_info;
u32 window;
u8 scale;
window = (u32)clib_net_to_host_u16(tcp->window_size);
calculate_window_scale(tcp, &scale);
dest_info.k.port = clib_net_to_host_u16(tcp->dest_port);
dest_info.k.ipv4 = clib_net_to_host_u32(ip->dest_addr);
PLATFORM_CNAT_SET_RX_VRF(vnet_buffer(b0)->sw_if_index[VLIB_RX],
dest_info.k.vrf, CNAT_TCP)
/* for TCP if not SYN or if src_port is 0, silently drop the packet */
if (PREDICT_FALSE(!((tcp->flags & TCP_FLAG_SYN) && (tcp->src_port)))) {
/*
* If the packet is dropped due to both reasons,
* count it as invalid packet drop
*/
if (!tcp->src_port) {
counter = CNAT_V4_TCP_I2O_E_D_INVALID_PKT;
} else {
counter = CNAT_V4_TCP_I2O_E_D_NON_SYN_PKT;
}
disposition = CNAT_V4_TCP_I2O_E_D;
goto in2out_e;
}
PLATFORM_CNAT_SET_RX_VRF(vnet_buffer(b0)->sw_if_index[VLIB_RX],
ki.k.k.vrf, CNAT_TCP)
ki.k.k.ipv4 = clib_net_to_host_u32(ip->src_addr);
ki.k.k.port = clib_net_to_host_u16(tcp->src_port);
db = cnat_get_main_db_entry_v2(&ki, PORT_SINGLE, PORT_TYPE_DYNAMIC, &info,
&dest_info);
#if DEBUG > 1
if(PREDICT_TRUE(db)) {
printf("create db %x ip %x->%x port %x->%x dst_ip %x\n", db,
db->in2out_key.k.ipv4, db->out2in_key.k.ipv4,
db->in2out_key.k.port, db->out2in_key.k.port, db->dst_ipv4);
}
#endif
if (PREDICT_FALSE(db == 0)) {
/* failed to create new db entry due to either no more port, or user limit reached,
* need to generate ICMP type=3,code=13 msg here,
*/
/*
* we rate limit the icmp msg per private user,
* so we don't flood a user with icmp msg
* in case the per user port limit reached
*/
if (PREDICT_TRUE(info.gen_icmp_msg == CNAT_ICMP_MSG)) {
/* KEEPING THINGS COMMENTED HERE..MAY NEED TO REVISIT AGAIN */
#if 0
u32 *fd = (u32*)ctx->feature_data;
fd[0] = info.svi_addr;
fd[1] = CNAT_ICMP_DEST_UNREACHABLE;
/*
* Let's reverse the direction from i2o to o2i.
* This will help using the correct VRF in the fib lookup (AVSM)
* especially for the o2i_vrf_override case
*/
ctx->ru.rx.direction = 0; // 0 - o2i, 1 - i2o
#endif
disposition = CNAT_V4_TCP_I2O_E_ICMP;
counter = CNAT_V4_TCP_I2O_E_GEN_ICMP;
} else {
disposition = CNAT_V4_TCP_I2O_E_D;
counter = CNAT_V4_TCP_I2O_E_DROP;
}
//DEBUG_I2O_DROP(CNAT_DEBUG_DROP_TCP)
} else {
if (PLATFORM_HANDLE_TTL_DECREMENT) {
/*
* Decrement TTL and update IPv4 checksum
*/
ipv4_decr_ttl_n_calc_csum(ip);
}
/* NAT the packet and fix checksum */
tcp_in2out_nat_mss_n_checksum(ip,
tcp,
db->out2in_key.k.ipv4,
db->out2in_key.k.port,
db
/*, db->in2out_key.k.vrf */);
/* this must be inside to outside SYN, do mss here */
/* update translation counters */
db->in2out_pkts++;
/* set keepalive timer */
if(PREDICT_TRUE((dest_info.k.ipv4 == db->dst_ipv4) &&
(dest_info.k.port == db->dst_port))) {
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);
db->scale = scale;
db->diff_window = window;
}
#if DEBUG > 1
PLATFORM_DEBUG_PRINT("\nMain DB seq no = %u,"
"ack no = %u, window = %u,"
"scale = %u",
db->proto_data.tcp_seq_chk.seq_no,
db->proto_data.tcp_seq_chk.ack_no,
db->diff_window
db->scale);
#endif
V4_TCP_UPDATE_SESSION_FLAG(db, tcp);
/* Check timeout db if there is config for this */
(void) query_and_update_db_timeout((void *)db, MAIN_DB_TYPE);
db->entry_expires = cnat_current_time;
} else {
/* Got to find out the session entry corresponding to this..*/
cnat_session_entry_t *sdb;
sdb = cnat_session_db_lookup_entry(
&dest_info, db - cnat_main_db);
if(PREDICT_FALSE(sdb == NULL)) {
disposition = CNAT_V4_TCP_I2O_E_D;
counter = CNAT_V4_TCP_I2O_E_D_NO_SESSION;
goto in2out_e;
}
sdb->tcp_seq_num = clib_net_to_host_u32(tcp->seq_num);
sdb->ack_no = clib_net_to_host_u32(tcp->ack_num);
sdb->scale = scale;
sdb->window = window;
#if DEBUG > 1
PLATFORM_DEBUG_PRINT("\nSDB seq no = %u, ack no = %u, window = %u"
"\nSDB scale = %u" ,
sdb->tcp_seq_num,
sdb->ack_no,
sdb->window,
sdb->scale);
#endif
V4_TCP_UPDATE_SESSION_DB_FLAG(sdb, tcp);
/* Check timeout db if there is config for this */
(void) query_and_update_db_timeout((void *)sdb, SESSION_DB_TYPE);
sdb->entry_expires = cnat_current_time;
}
//PLATFORM_CNAT_SET_TX_VRF(ctx,db->out2in_key.k.vrf)
counter = CNAT_V4_TCP_I2O_E_T_PKT;
in2out_forwarding_count++;
}
in2out_e:
em->counters[node_counter_base_index + counter] += 1;
return disposition;
}
#include <vnet/pipeline.h>
static uword cnat_ipv4_tcp_inside_input_exc_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_exc_node) = {
.function = cnat_ipv4_tcp_inside_input_exc_node_fn,
.name = "vcgn-v4-tcp-i2o-e",
.vector_size = sizeof (u32),
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(cnat_ipv4_tcp_inside_input_exc_error_strings),
.error_strings = cnat_ipv4_tcp_inside_input_exc_error_strings,
.n_next_nodes = CNAT_V4_TCP_I2O_E_NEXT,
/* edit / add dispositions here */
.next_nodes = {
[CNAT_V4_TCP_I2O_E_T] = "ip4-input",
[CNAT_V4_TCP_I2O_E_D] = "error-drop",
},
};
clib_error_t *cnat_ipv4_tcp_inside_input_exc_init (vlib_main_t *vm)
{
cnat_ipv4_tcp_inside_input_exc_main_t * mp = &cnat_ipv4_tcp_inside_input_exc_main;
mp->vlib_main = vm;
mp->vnet_main = vnet_get_main();
return 0;
}
VLIB_INIT_FUNCTION (cnat_ipv4_tcp_inside_input_exc_init);