/*
* Copyright (c) 2016-2019 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.
*/
/*
* ip/tcp_pg: TCP packet-generator interface
*
* Copyright (c) 2008 Eliot Dresselhaus
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <vnet/ip/ip.h>
#include <vnet/pg/pg.h>
/* TCP flags bit 0 first. */
#define foreach_tcp_flag \
_ (FIN) \
_ (SYN) \
_ (RST) \
_ (PSH) \
_ (ACK) \
_ (URG) \
_ (ECE) \
_ (CWR)
static void
tcp_pg_edit_function (pg_main_t * pg,
pg_stream_t * s,
pg_edit_group_t * g, u32 * packets, u32 n_packets)
{
vlib_main_t *vm = vlib_get_main ();
u32 ip_offset, tcp_offset;
tcp_offset = g->start_byte_offset;
ip_offset = (g - 1)->start_byte_offset;
while (n_packets >= 1)
{
vlib_buffer_t *p0;
ip4_header_t *ip0;
tcp_header_t *tcp0;
ip_csum_t sum0;
u32 tcp_len0;
p0 = vlib_get_buffer (vm, packets[0]);
n_packets -= 1;
packets += 1;
ASSERT (p0->current_data == 0);
ip0 = (void *) (p0->data + ip_offset);
tcp0 = (void *) (p0->data + tcp_offset);
/* if IP length has been specified, then calculate the length based on buffer */
if (ip0->length == 0)
tcp_len0 = vlib_buffer_length_in_chain (vm, p0) - tcp_offset;
else
tcp_len0 = clib_net_to_host_u16 (ip0->length) - tcp_offset;
/* Initialize checksum with header. */
if (BITS (sum0) == 32)
{
sum0 = clib_mem_unaligned (&ip0->src_address, u32);
sum0 =
ip_csum_with_carry (sum0,
clib_mem_unaligned (&ip0->dst_address, u32));
}
else
sum0 = clib_mem_unaligned (&ip0->src_address, u64);
sum0 = ip_csum_with_carry
(sum0, clib_host_to_net_u32 (tcp_len0 + (ip0->protocol << 16)));
/* Invalidate possibly old checksum. */
tcp0->checksum = 0;
sum0 =
ip_incremental_checksum_buffer (vm, p0, tcp_offset, tcp_len0, sum0);
tcp0->checksum = ~ip_csum_fold (sum0);
}
}
typedef struct
{
pg_edit_t src, dst;
pg_edit_t seq_number, ack_number;
pg_edit_t data_offset_and_reserved;
#define _(f) pg_edit_t f##_flag;
foreach_tcp_flag
#undef _
pg_edit_t window;
pg_edit_t checksum;
pg_edit_t urgent_pointer;
} pg_tcp_header_t;
static inline void
pg_tcp_header_init (pg_tcp_header_t * p)
{
/* Initialize fields that are not bit fields in the IP header. */
#define _(f) pg_edit_init (&p->f, tcp_header_t, f);
_(src);
_(dst);
_(seq_number);
_(ack_number);
_(window);
_(checksum);
_(urgent_pointer);
#undef _
/* Initialize bit fields. */
#define _(f) \
pg_edit_init_bitfield (&p->f##_flag, tcp_header_t, \
flags, \
TCP_FLAG_BIT_##f, 1);
foreach_tcp_flag
#undef _
pg_edit_init_bitfield (&p->data_offset_and_reserved, tcp_header_t,
data_offset_and_reserved, 4, 4);
}
uword
unformat_pg_tcp_header (unformat_input_t * input, va_list * args)
{
pg_stream_t *s = va_arg (*args, pg_stream_t *);
pg_tcp_header_t *p;
u32 group_index;
p = pg_create_edit_group (s, sizeof (p[0]), sizeof (tcp_header_t),
&group_index);
pg_tcp_header_init (p);
/* Defaults. */
pg_edit_set_fixed (&p->seq_number, 0);
pg_edit_set_fixed (&p->ack_number, 0);
pg_edit_set_fixed (&p->data_offset_and_reserved,
sizeof (tcp_header_t) / sizeof (u32));
pg_edit_set_fixed (&p->window, 4096);
pg_edit_set_fixed (&p->urgent_pointer, 0);
#define _(f) pg_edit_set_fixed (&p->f##_flag, 0);
foreach_tcp_flag
#undef _
p->checksum.type = PG_EDIT_UNSPECIFIED;
if (!unformat (input, "TCP: %U -> %U",
unformat_pg_edit,
unformat_tcp_udp_port, &p->src,
unformat_pg_edit, unformat_tcp_udp_port, &p->dst))
goto error;
/* Parse options. */
while (1)
{
if (unformat (input, "window %U",
unformat_pg_edit, unformat_pg_number, &p->window))
;
else if (unformat (input, "checksum %U",
unformat_pg_edit, unformat_pg_number, &p->checksum))
;
else if (unformat (input, "seqnum %U", unformat_pg_edit,
unformat_pg_number, &p->seq_number))
;
else if (unformat (input, "acknum %U", unformat_pg_edit,
unformat_pg_number, &p->ack_number))
;
/* Flags. */
#define _(f) else if (unformat (input, #f)) pg_edit_set_fixed (&p->f##_flag, 1);
foreach_tcp_flag
#undef _
/* Can't parse input: try next protocol level. */
else
break;
}
{
ip_main_t *im = &ip_main;
u16 dst_port;
tcp_udp_port_info_t *pi;
pi = 0;
if (p->dst.type == PG_EDIT_FIXED)
{
dst_port = pg_edit_get_value (&p->dst, PG_EDIT_LO);
pi = ip_get_tcp_udp_port_info (im, dst_port);
}
if (pi && pi->unformat_pg_edit
&& unformat_user (input, pi->unformat_pg_edit, s))
;
else if (!unformat_user (input, unformat_pg_payload, s))
goto error;
if (p->checksum.type == PG_EDIT_UNSPECIFIED)
{
pg_edit_group_t *g = pg_stream_get_group (s, group_index);
g->edit_function = tcp_pg_edit_function;
g->edit_function_opaque = 0;
}
return 1;
}
error:
/* Free up any edits we may have added. */
pg_free_edit_group (s);
return 0;
}
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
