/* * 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 #include /* 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: */