1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
/*
* Copyright (c) 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.
*/
#include <fcntl.h>
#include <vppinfra/mpcap.h>
/*
* Unfortunately, the "make test" infra won't work with mapped pcap files.
* Given enough work [mostly in .py code], one could fix that.
*/
/**
* @file
* @brief mapped pcap file support
*
* Usage:
*
* <code><pre>
* \#include <vnet/unix/mpcap.h>
*
* static mpcap_main_t mpcap = {
* .file_name = "/tmp/ip4",
* .n_packets_to_capture = 2,
* .packet_type = MPCAP_PACKET_TYPE_ip,
* };
* </pre></code>
*
* To add a buffer:
*
* <code><pre>mpcap_add_buffer (&mpcap, vm, pi0, 128);</pre></code>
*
* File will be written after @c n_packets_to_capture
* or call to mpcap_close
*
*/
/**
* @brief Close a mapped pcap file
* @param mpcap_main_t * pm
* @return rc - clib_error_t
*
*/
__clib_export clib_error_t *
mpcap_close (mpcap_main_t * pm)
{
u64 actual_size = pm->current_va - pm->file_baseva;
/* Not open? Done... */
if ((pm->flags & MPCAP_FLAG_INIT_DONE) == 0)
return 0;
(void) munmap (pm->file_baseva, pm->max_file_size);
pm->file_baseva = 0;
pm->current_va = 0;
pm->flags &= ~MPCAP_FLAG_INIT_DONE;
if ((pm->flags & MPCAP_FLAG_WRITE_ENABLE) == 0)
return 0;
if (truncate (pm->file_name, actual_size) < 0)
clib_unix_warning ("setting file size to %llu", actual_size);
return 0;
}
/**
* @brief Initialize a mapped pcap file
* @param mpcap_main_t * pm
* @return rc - clib_error_t
*
*/
__clib_export clib_error_t *
mpcap_init (mpcap_main_t * pm)
{
mpcap_file_header_t *fh;
u8 zero = 0;
int fd;
if (pm->flags & MPCAP_FLAG_INIT_DONE)
return 0;
if (!pm->file_name)
pm->file_name = "/tmp/vppinfra.mpcap";
if (pm->flags & MPCAP_FLAG_THREAD_SAFE)
clib_spinlock_init (&pm->lock);
fd = open (pm->file_name, O_CREAT | O_TRUNC | O_RDWR, 0664);
if (fd < 0)
{
return clib_error_return_unix (0, "failed to create `%s'",
pm->file_name);
}
if (pm->max_file_size == 0ULL)
pm->max_file_size = MPCAP_DEFAULT_FILE_SIZE;
/* Round to a multiple of the page size */
pm->max_file_size += (u64) clib_mem_get_page_size ();
pm->max_file_size &= ~(u64) clib_mem_get_page_size ();
/* Set file size. */
if (lseek (fd, pm->max_file_size - 1, SEEK_SET) == (off_t) - 1)
{
close (fd);
(void) unlink (pm->file_name);
return clib_error_return_unix (0, "file size seek");
}
if (write (fd, &zero, 1) != 1)
{
close (fd);
(void) unlink (pm->file_name);
return clib_error_return_unix (0, "file size write");
}
pm->file_baseva = mmap (0, pm->max_file_size,
PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (pm->file_baseva == (u8 *) MAP_FAILED)
{
clib_error_t *error = clib_error_return_unix (0, "mmap");
close (fd);
(void) unlink (pm->file_name);
return error;
}
(void) close (fd);
pm->flags |= MPCAP_FLAG_INIT_DONE | MPCAP_FLAG_WRITE_ENABLE;
pm->n_packets_captured = 0;
pm->n_mpcap_data_written = 0;
/* Initialize file header */
fh = pm->file_header = (mpcap_file_header_t *) pm->file_baseva;
pm->current_va = pm->file_baseva + sizeof (*fh);
fh->magic = 0xa1b2c3d4;
fh->major_version = 2;
fh->minor_version = 4;
fh->time_zone = 0;
fh->max_packet_size_in_bytes = 1 << 16;
fh->packet_type = pm->packet_type;
return 0;
}
/**
* @brief mmap a mapped pcap file, e.g. to read from another process
* @param pcap_main_t *pm
* @return rc - clib_error_t
*/
clib_error_t *
mpcap_map (mpcap_main_t * pm)
{
clib_error_t *error = 0;
int fd = -1;
mpcap_file_header_t *fh;
mpcap_packet_header_t *ph;
struct stat statb;
u64 packets_read = 0;
u32 min_packet_bytes = ~0;
u32 max_packet_bytes = 0;
fd = open (pm->file_name, O_RDONLY);
if (fd < 0)
{
error = clib_error_return_unix (0, "open `%s'", pm->file_name);
goto done;
}
if (fstat (fd, &statb) < 0)
{
error = clib_error_return_unix (0, "stat `%s'", pm->file_name);
goto done;
}
if ((statb.st_mode & S_IFREG) == 0)
{
error = clib_error_return (0, "'%s' is not a regular file",
pm->file_name);
goto done;
}
if (statb.st_size < sizeof (*fh) + sizeof (*ph))
{
error = clib_error_return_unix (0, "`%s' is too short", pm->file_name);
goto done;
}
pm->max_file_size = statb.st_size;
pm->file_baseva = mmap (0, statb.st_size, PROT_READ, MAP_SHARED, fd, 0);
if (pm->file_baseva == (u8 *) MAP_FAILED)
{
error = clib_error_return_unix (0, "mmap");
goto done;
}
pm->flags |= MPCAP_FLAG_INIT_DONE;
fh = pm->file_header = (mpcap_file_header_t *) pm->file_baseva;
ph = (mpcap_packet_header_t *) (fh + 1);
if (fh->magic != 0xa1b2c3d4)
{
error = clib_error_return (0, "bad magic `%s'", pm->file_name);
pm->flags &= ~(MPCAP_FLAG_INIT_DONE);
(void) munmap (pm->file_baseva, pm->max_file_size);
goto done;
}
/* for the client's convenience, count packets; compute min/max sizes */
while (ph < (mpcap_packet_header_t *) pm->file_baseva + pm->max_file_size)
{
if (ph->n_packet_bytes_stored_in_file == 0)
break;
packets_read++;
min_packet_bytes =
ph->n_packet_bytes_stored_in_file <
min_packet_bytes ? ph->n_packet_bytes_stored_in_file :
min_packet_bytes;
max_packet_bytes =
ph->n_packet_bytes_stored_in_file >
max_packet_bytes ? ph->n_packet_bytes_stored_in_file :
max_packet_bytes;
ph = (mpcap_packet_header_t *)
(((u8 *) (ph)) + sizeof (*ph) + ph->n_packet_bytes_stored_in_file);
}
pm->packets_read = packets_read;
pm->min_packet_bytes = min_packet_bytes;
pm->max_packet_bytes = max_packet_bytes;
done:
if (fd >= 0)
close (fd);
return error;
}
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
|
