/* * 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. */ /* * ip/ip4_pg: IP v4 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> #define IP4_PG_EDIT_CHECKSUM (1 << 0) #define IP4_PG_EDIT_LENGTH (1 << 1) static_always_inline void compute_length_and_or_checksum (vlib_main_t * vm, u32 * packets, u32 n_packets, u32 ip_header_offset, u32 flags) { ASSERT (flags != 0); while (n_packets >= 2) { u32 pi0, pi1; vlib_buffer_t *p0, *p1; ip4_header_t *ip0, *ip1; ip_csum_t sum0, sum1; pi0 = packets[0]; pi1 = packets[1]; p0 = vlib_get_buffer (vm, pi0); p1 = vlib_get_buffer (vm, pi1); n_packets -= 2; packets += 2; ip0 = (void *) (p0->data + ip_header_offset); ip1 = (void *) (p1->data + ip_header_offset); if (flags & IP4_PG_EDIT_LENGTH) { ip0->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, p0) - ip_header_offset); ip1->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, p1) - ip_header_offset); } if (flags & IP4_PG_EDIT_CHECKSUM) { ASSERT (ip4_header_bytes (ip0) == sizeof (ip0[0])); ASSERT (ip4_header_bytes (ip1) == sizeof (ip1[0])); ip0->checksum = 0; ip1->checksum = 0; ip4_partial_header_checksum_x2 (ip0, ip1, sum0, sum1); ip0->checksum = ~ip_csum_fold (sum0); ip1->checksum = ~ip_csum_fold (sum1); ASSERT (ip0->checksum == ip4_header_checksum (ip0)); ASSERT (ip1->checksum == ip4_header_checksum (ip1)); } } while (n_packets >= 1) { u32 pi0; vlib_buffer_t *p0; ip4_header_t *ip0; ip_csum_t sum0; pi0 = packets[0]; p0 = vlib_get_buffer (vm, pi0); n_packets -= 1; packets += 1; ip0 = (void *) (p0->data + ip_header_offset); if (flags & IP4_PG_EDIT_LENGTH) ip0->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, p0) - ip_header_offset); if (flags & IP4_PG_EDIT_CHECKSUM) { ASSERT (ip4_header_bytes (ip0) == sizeof (ip0[0])); ip0->checksum = 0; ip4_partial_header_checksum_x1 (ip0, sum0); ip0->checksum = ~ip_csum_fold (sum0); ASSERT (ip0->checksum == ip4_header_checksum (ip0)); } } } static void ip4_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; ip_offset = g->start_byte_offset; switch (g->edit_function_opaque) { case IP4_PG_EDIT_LENGTH: compute_length_and_or_checksum (vm, packets, n_packets, ip_offset, IP4_PG_EDIT_LENGTH); break; case IP4_PG_EDIT_CHECKSUM: compute_length_and_or_checksum (vm, packets, n_packets, ip_offset, IP4_PG_EDIT_CHECKSUM); break; case IP4_PG_EDIT_LENGTH | IP4_PG_EDIT_CHECKSUM: compute_length_and_or_checksum (vm, packets, n_packets, ip_offset, IP4_PG_EDIT_LENGTH | IP4_PG_EDIT_CHECKSUM); break; default: ASSERT (0); break; } } typedef struct { pg_edit_t ip_version, header_length; pg_edit_t tos; pg_edit_t length; pg_edit_t fragment_id, fragment_offset; /* Flags together with fragment offset. */ pg_edit_t mf_flag, df_flag, ce_flag; pg_edit_t ttl; pg_edit_t protocol; pg_edit_t checksum; pg_edit_t src_address, dst_address; } pg_ip4_header_t; static inline void pg_ip4_header_init (pg_ip4_header_t * p) { /* Initialize fields that are not bit fields in the IP header. */ #define _(f) pg_edit_init (&p->f, ip4_header_t, f); _(tos); _(length); _(fragment_id); _(ttl); _(protocol); _(checksum); _(src_address); _(dst_address); #undef _ /* Initialize bit fields. */ pg_edit_init_bitfield (&p->header_length, ip4_header_t, ip_version_and_header_length, 0, 4); pg_edit_init_bitfield (&p->ip_version, ip4_header_t, ip_version_and_header_length, 4, 4); pg_edit_init_bitfield (&p->fragment_offset, ip4_header_t, flags_and_fragment_offset, 0, 13); pg_edit_init_bitfield (&p->mf_flag, ip4_header_t, flags_and_fragment_offset, 13, 1); pg_edit_init_bitfield (&p->df_flag, ip4_header_t, flags_and_fragment_offset, 14, 1); pg_edit_init_bitfield (&p->ce_flag, ip4_header_t, flags_and_fragment_offset, 15, 1); } uword unformat_pg_ip4_header (unformat_input_t * input, va_list * args) { pg_stream_t *s = va_arg (*args, pg_stream_t *); pg_ip4_header_t *p; u32 group_index; p = pg_create_edit_group (s, sizeof (p[0]), sizeof (ip4_header_t), &group_index); pg_ip4_header_init (p); /* Defaults. */ pg_edit_set_fixed (&p->ip_version, 4); pg_edit_set_fixed (&p->header_length, sizeof (ip4_header_t) / sizeof (u32)); pg_edit_set_fixed (&p->tos, 0); pg_edit_set_fixed (&p->ttl, 64); pg_edit_set_fixed (&p->fragment_id, 0); pg_edit_set_fixed (&p->fragment_offset, 0); pg_edit_set_fixed (&p->mf_flag, 0); pg_edit_set_fixed (&p->df_flag, 0); pg_edit_set_fixed (&p->ce_flag, 0); p->length.type = PG_EDIT_UNSPECIFIED; p->checksum.type = PG_EDIT_UNSPECIFIED; if (unformat (input, "%U: %U -> %U", unformat_pg_edit, unformat_ip_protocol, &p->protocol, unformat_pg_edit, unformat_ip4_address, &p->src_address, unformat_pg_edit, unformat_ip4_address, &p->dst_address)) goto found; if (!unformat (input, "%U:", unformat_pg_edit, unformat_ip_protocol, &p->protocol)) goto error; found: /* Parse options. */ while (1) { if (unformat (input, "version %U", unformat_pg_edit, unformat_pg_number, &p->ip_version)) ; else if (unformat (input, "header-length %U", unformat_pg_edit, unformat_pg_number, &p->header_length)) ; else if (unformat (input, "tos %U", unformat_pg_edit, unformat_pg_number, &p->tos)) ; else if (unformat (input, "length %U", unformat_pg_edit, unformat_pg_number, &p->length)) ; else if (unformat (input, "checksum %U", unformat_pg_edit, unformat_pg_number, &p->checksum)) ; else if (unformat (input, "ttl %U", unformat_pg_edit, unformat_pg_number, &p->ttl)) ; else if (unformat (input, "fragment id %U offset %U", unformat_pg_edit, unformat_pg_number, &p->fragment_id, unformat_pg_edit, unformat_pg_number, &p->fragment_offset)) { int i; for (i = 0; i < ARRAY_LEN (p->fragment_offset.values); i++) pg_edit_set_value (&p->fragment_offset, i, pg_edit_get_value (&p->fragment_offset, i) / 8); } /* Flags. */ else if (unformat (input, "mf") || unformat (input, "MF")) pg_edit_set_fixed (&p->mf_flag, 1); else if (unformat (input, "df") || unformat (input, "DF")) pg_edit_set_fixed (&p->df_flag, 1); else if (unformat (input, "ce") || unformat (input, "CE")) pg_edit_set_fixed (&p->ce_flag, 1); /* Can't parse input: try next protocol level. */ else break; } { ip_main_t *im = &ip_main; ip_protocol_t protocol; ip_protocol_info_t *pi; pi = 0; if (p->protocol.type == PG_EDIT_FIXED) { protocol = pg_edit_get_value (&p->protocol, PG_EDIT_LO); pi = ip_get_protocol_info (im, protocol); } 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->length.type == PG_EDIT_UNSPECIFIED && s->min_packet_bytes == s->max_packet_bytes && group_index + 1 < vec_len (s->edit_groups)) { pg_edit_set_fixed (&p->length, pg_edit_group_n_bytes (s, group_index)); } /* Compute IP header checksum if all edits are fixed. */ if (p->checksum.type == PG_EDIT_UNSPECIFIED) { ip4_header_t fixed_header, fixed_mask, cmp_mask; /* See if header is all fixed and specified except for checksum field. */ memset (&cmp_mask, ~0, sizeof (cmp_mask)); cmp_mask.checksum = 0; pg_edit_group_get_fixed_packet_data (s, group_index, &fixed_header, &fixed_mask); if (!memcmp (&fixed_mask, &cmp_mask, sizeof (cmp_mask))) pg_edit_set_fixed (&p->checksum, clib_net_to_host_u16 (ip4_header_checksum (&fixed_header))); } p = pg_get_edit_group (s, group_index); if (p->length.type == PG_EDIT_UNSPECIFIED || p->checksum.type == PG_EDIT_UNSPECIFIED) { pg_edit_group_t *g = pg_stream_get_group (s, group_index); g->edit_function = ip4_pg_edit_function; g->edit_function_opaque = 0; if (p->length.type == PG_EDIT_UNSPECIFIED) g->edit_function_opaque |= IP4_PG_EDIT_LENGTH; if (p->checksum.type == PG_EDIT_UNSPECIFIED) g->edit_function_opaque |= IP4_PG_EDIT_CHECKSUM; } 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: */