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Diffstat (limited to 'src/vnet/rewrite.h')
| -rw-r--r-- | src/vnet/rewrite.h | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/src/vnet/rewrite.h b/src/vnet/rewrite.h new file mode 100644 index 00000000000..00c1efbdc5e --- /dev/null +++ b/src/vnet/rewrite.h @@ -0,0 +1,305 @@ +/* + * 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; + + /* 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)) + +#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: + */ |