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81/*
* Copyright (c) 2015 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.
*/
/*
* rewrite.h: packet rewrite
*
* 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.
*/
#ifndef included_vnet_rewrite_h
#define included_vnet_rewrite_h
#include <vlib/vlib.h>
#include <vnet/l3_types.h>
/* Consider using vector types for speed? */
typedef uword vnet_rewrite_data_t;
/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
/* Interface to mark re-written packets with. */
u32 sw_if_index;
/* Packet processing node where rewrite happens. */
u32 node_index;
/* Next node to feed after packet rewrite is done. */
u16 next_index;
/* Number of bytes in rewrite data. */
u16 data_bytes;
/* Max packet size layer 3 (MTU) for output interface.
Used for MTU check after packet rewrite. */
u16 max_l3_packet_bytes;
/* When dynamically writing a multicast destination L2 addresss
* this is the offset within the address to start writing n
* bytes of the IP mcast address */
u8 dst_mcast_offset;
/* When dynamically writing a multicast destination L2 addresss
* this is the number of bytes of the dest IP address to write into
* the MAC rewrite */
u8 dst_mcast_n_bytes;
/* Rewrite string starting at end and going backwards. */
u8 data[0];
}) vnet_rewrite_header_t;
/* *INDENT-ON* */
/*
Helper macro for declaring rewrite string w/ given max-size.
Typical usage:
typedef struct {
//
int a, b;
// Total adjacency is 64 bytes.
vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
} my_adjacency_t;
*/
#define vnet_declare_rewrite(total_bytes) \
struct { \
vnet_rewrite_header_t rewrite_header; \
\
u8 rewrite_data[(total_bytes) - sizeof (vnet_rewrite_header_t)]; \
}
always_inline void
vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
{
/* Sanity check values carefully for this memset operation */
ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
rw->data_bytes = 0;
memset (rw->data, 0xfe, max_size);
}
always_inline void
vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
int max_size, void *data, int data_bytes)
{
/* Sanity check values carefully for this memset operation */
ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
rw->data_bytes = data_bytes;
clib_memcpy (rw->data + max_size - data_bytes, data, data_bytes);
memset (rw->data, 0xfe, max_size - data_bytes);
}
#define vnet_rewrite_set_data(rw,data,data_bytes) \
vnet_rewrite_set_data_internal (&((rw).rewrite_header), \
sizeof ((rw).rewrite_data), \
(data), \
(data_bytes))
always_inline void *
vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
{
ASSERT (rw->data_bytes <= max_size);
return rw->data + max_size - rw->data_bytes;
}
#define vnet_rewrite_get_data(rw) \
vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
always_inline void
vnet_rewrite_copy_one (vnet_rewrite_data_t * p0, vnet_rewrite_data_t * rw0,
int i)
{
p0[-i] = rw0[-i];
}
void vnet_rewrite_copy_slow_path (vnet_rewrite_data_t * p0,
vnet_rewrite_data_t * rw0,
word n_left, uword most_likely_size);
/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
u64 a;
u32 b;
u16 c;
}) eh_copy_t;
/* *INDENT-ON* */
always_inline void
_vnet_rewrite_one_header (vnet_rewrite_header_t * h0,
void *packet0, int max_size, int most_likely_size)
{
vnet_rewrite_data_t *p0 = packet0;
vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
word n_left0;
/* 0xfefe => poisoned adjacency => crash */
ASSERT (h0->data_bytes != 0xfefe);
if (PREDICT_TRUE (h0->data_bytes == sizeof (eh_copy_t)))
{
eh_copy_t *s, *d;
s = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
d = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
clib_memcpy (d, s, sizeof (eh_copy_t));
return;
}
#define _(i) \
do { \
if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
vnet_rewrite_copy_one (p0, rw0, (i)); \
} while (0)
_(4);
_(3);
_(2);
_(1);
#undef _
n_left0 = (int)
(((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
/ (int) sizeof (rw0[0]);
if (PREDICT_FALSE (n_left0 > 0))
vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
}
always_inline void
_vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
vnet_rewrite_header_t * h1,
void *packet0,
void *packet1, int max_size, int most_likely_size)
{
vnet_rewrite_data_t *p0 = packet0;
vnet_rewrite_data_t *p1 = packet1;
vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
vnet_rewrite_data_t *rw1 = (vnet_rewrite_data_t *) (h1->data + max_size);
word n_left0, n_left1;
int slow_path;
/* 0xfefe => poisoned adjacency => crash */
ASSERT (h0->data_bytes != 0xfefe);
ASSERT (h1->data_bytes != 0xfefe);
/* Arithmetic calculation: bytes0 == bytes1 == 14 */
slow_path = h0->data_bytes ^ h1->data_bytes;
slow_path += h0->data_bytes ^ sizeof (eh_copy_t);
if (PREDICT_TRUE (slow_path == 0))
{
eh_copy_t *s0, *d0, *s1, *d1;
s0 = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
d0 = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
clib_memcpy (d0, s0, sizeof (eh_copy_t));
s1 = (eh_copy_t *) (h1->data + max_size - sizeof (eh_copy_t));
d1 = (eh_copy_t *) (((u8 *) packet1) - sizeof (eh_copy_t));
clib_memcpy (d1, s1, sizeof (eh_copy_t));
return;
}
#define _(i) \
do { \
if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
{ \
vnet_rewrite_copy_one (p0, rw0, (i)); \
vnet_rewrite_copy_one (p1, rw1, (i)); \
} \
} while (0)
_(4);
_(3);
_(2);
_(1);
#undef _
n_left0 = (int)
(((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
/ (int) sizeof (rw0[0]);
n_left1 = (int)
(((int) h1->data_bytes - most_likely_size) + (sizeof (rw1[0]) - 1))
/ (int) sizeof (rw1[0]);
if (PREDICT_FALSE (n_left0 > 0 || n_left1 > 0))
{
vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
vnet_rewrite_copy_slow_path (p1, rw1, n_left1, most_likely_size);
}
}
#define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
_vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
sizeof ((rw0).rewrite_data), \
(most_likely_size))
#define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
_vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
(p0), (p1), \
sizeof ((rw0).rewrite_data), \
(most_likely_size))
always_inline void
_vnet_fixup_one_header (vnet_rewrite_header_t * h0,
u8 * addr, u32 addr_len,
u8 * packet0, int clear_first_bit)
{
/* location to write to in the packet */
u8 *p0 = packet0 - h0->dst_mcast_offset;
u8 *p1 = p0;
/* location to write from in the L3 dest address */
u8 *a0 = addr + addr_len - h0->dst_mcast_n_bytes;
clib_memcpy (p0, a0, h0->dst_mcast_n_bytes);
if (clear_first_bit)
*p1 &= 0x7f;
}
#define vnet_fixup_one_header(rw0,addr,p0,clear_first_bit) \
_vnet_fixup_one_header (&((rw0).rewrite_header), \
(u8*)(addr), sizeof((*addr)), \
(u8*)(p0), (clear_first_bit))
#define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
/** Deprecated */
void vnet_rewrite_for_sw_interface (struct vnet_main_t *vnm,
vnet_link_t packet_type,
u32 sw_if_index,
u32 node_index,
void *dst_address,
vnet_rewrite_header_t * rw,
u32 max_rewrite_bytes);
u32 vnet_tx_node_index_for_sw_interface (struct vnet_main_t *vnm,
u32 sw_if_index);
void vnet_rewrite_init (struct vnet_main_t *vnm,
u32 sw_if_index,
u32 this_node,
u32 next_node, vnet_rewrite_header_t * rw);
u8 *vnet_build_rewrite_for_sw_interface (struct vnet_main_t *vnm,
u32 sw_if_index,
vnet_link_t packet_type,
const void *dst_address);
void vnet_update_adjacency_for_sw_interface (struct vnet_main_t *vnm,
u32 sw_if_index, u32 ai);
/* Parser for unformat header & rewrite string. */
unformat_function_t unformat_vnet_rewrite;
format_function_t format_vnet_rewrite;
format_function_t format_vnet_rewrite_header;
serialize_function_t serialize_vnet_rewrite, unserialize_vnet_rewrite;
#endif /* included_vnet_rewrite_h */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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