2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * pcap.c: libpcap packet capture format
18 * Copyright (c) 2008 Eliot Dresselhaus
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 #include <vnet/unix/pcap.h>
41 #include <sys/fcntl.h>
45 #include <vnet/unix/pcap.h>
47 static pcap_main_t pcap = {
48 .file_name = "/tmp/ip4",
49 .n_packets_to_capture = 2,
50 .packet_type = PCAP_PACKET_TYPE_ip,
55 pcap_add_buffer (&pcap, vm, pi0, 128);
57 file will be written after n_packets_to_capture or call to pcap_write (&pcap).
62 pcap_write (pcap_main_t * pm)
64 clib_error_t * error = 0;
66 if (! (pm->flags & PCAP_MAIN_INIT_DONE))
68 pcap_file_header_t fh;
72 pm->file_name = "/tmp/vnet.pcap";
74 pm->file_descriptor = open (pm->file_name, O_CREAT | O_TRUNC | O_WRONLY, 0664);
75 if (pm->file_descriptor < 0)
77 error = clib_error_return_unix (0, "failed to open `%s'", pm->file_name);
81 pm->flags |= PCAP_MAIN_INIT_DONE;
82 pm->n_packets_captured = 0;
83 pm->n_pcap_data_written = 0;
85 /* Write file header. */
86 memset (&fh, 0, sizeof (fh));
87 fh.magic = 0xa1b2c3d4;
91 fh.max_packet_size_in_bytes = 1 << 16;
92 fh.packet_type = pm->packet_type;
93 n = write (pm->file_descriptor, &fh, sizeof (fh));
97 error = clib_error_return_unix (0, "write file header `%s'", pm->file_name);
99 error = clib_error_return (0, "short write of file header `%s'", pm->file_name);
105 int n = vec_len (pm->pcap_data) - pm->n_pcap_data_written;
109 n = write (pm->file_descriptor,
110 vec_elt_at_index (pm->pcap_data, pm->n_pcap_data_written),
112 if (n < 0 && unix_error_is_fatal (errno))
114 error = clib_error_return_unix (0, "write `%s'", pm->file_name);
118 pm->n_pcap_data_written += n;
119 if (pm->n_pcap_data_written >= vec_len (pm->pcap_data))
121 vec_reset_length (pm->pcap_data);
124 } while (pm->n_packets_captured >= pm->n_packets_to_capture);
126 if (pm->n_packets_captured >= pm->n_packets_to_capture)
128 close (pm->file_descriptor);
129 pm->flags &= ~PCAP_MAIN_INIT_DONE;
130 pm->file_descriptor = -1;
136 if (pm->file_descriptor >= 0)
137 close (pm->file_descriptor);
142 clib_error_t * pcap_read (pcap_main_t * pm)
144 clib_error_t * error = 0;
145 int fd, need_swap, n;
146 pcap_file_header_t fh;
147 pcap_packet_header_t ph;
149 fd = open (pm->file_name, O_RDONLY);
152 error = clib_error_return_unix (0, "open `%s'", pm->file_name);
156 if (read (fd, &fh, sizeof (fh)) != sizeof (fh))
158 error = clib_error_return_unix (0, "read file header `%s'", pm->file_name);
163 if (fh.magic == 0xd4c3b2a1)
166 #define _(t,f) fh.f = clib_byte_swap_##t (fh.f);
167 foreach_pcap_file_header;
171 if (fh.magic != 0xa1b2c3d4)
173 error = clib_error_return (0, "bad magic `%s'", pm->file_name);
177 pm->min_packet_bytes = 0;
178 pm->max_packet_bytes = 0;
179 while ((n = read (fd, &ph, sizeof (ph))) != 0)
185 #define _(t,f) ph.f = clib_byte_swap_##t (ph.f);
186 foreach_pcap_packet_header;
190 data = vec_new (u8, ph.n_bytes_in_packet);
191 if (read (fd, data, ph.n_packet_bytes_stored_in_file) != ph.n_packet_bytes_stored_in_file)
193 error = clib_error_return (0, "short read `%s'", pm->file_name);
197 if (vec_len (pm->packets_read) == 0)
198 pm->min_packet_bytes = pm->max_packet_bytes = ph.n_bytes_in_packet;
201 pm->min_packet_bytes = clib_min (pm->min_packet_bytes, ph.n_bytes_in_packet);
202 pm->max_packet_bytes = clib_max (pm->max_packet_bytes, ph.n_bytes_in_packet);
205 vec_add1 (pm->packets_read, data);