/* * 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 #include /* Consider using vector types for speed? */ typedef uword vnet_rewrite_data_t; /** * Flags associated with the rewrite/adjacency */ typedef enum vnet_rewrite_flags_t_ { /** * This adjacency/interface has output features configured */ VNET_REWRITE_HAS_FEATURES = (1 << 0), } __attribute__ ((packed)) vnet_rewrite_flags_t; /* *INDENT-OFF* */ typedef CLIB_PACKED (struct { /* Interface to mark re-written packets with. */ u32 sw_if_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; /* Data-plane flags on the adjacency/rewrite */ vnet_rewrite_flags_t flags; /* When dynamically writing a multicast destination L2 addresss * this is the offset from the IP address at which to write in the * IP->MAC address translation. */ u8 dst_mcast_offset; /* The mask to apply to the lower 4 bytes of the IP address before ORing * into the destinaiton MAC address */ u32 dst_mcast_mask; /* Rewrite string starting at end and going backwards. */ u8 data[0]; }) vnet_rewrite_header_t; /* *INDENT-ON* */ /** * At 16 bytes of rewrite herader we have enought space left for a IPv6 * (40 bytes) + LISP-GPE (8 bytes) in the cache line */ STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16, "Rewrite header too big"); /* 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_l