blob: 8f644e30f1dc2a8db9e643c41361b711164f8d5d [file] [log] [blame]
/*
* 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.
*/
/*
* pcap.c: libpcap packet capture format
*
* 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 <sys/fcntl.h>
#include <vppinfra/pcap.h>
/**
* @file
* @brief PCAP function.
*
* Usage:
*
* <code><pre>
* \#include <vppinfra/pcap.h>
*
* static pcap_main_t pcap = {
* .file_name = "/tmp/ip4",
* .n_packets_to_capture = 2,
* .packet_type = PCAP_PACKET_TYPE_ip,
* };
* </pre></code>
*
* To add a buffer:
*
* <code><pre>pcap_add_buffer (&pcap, vm, pi0, 128);</pre></code>
*
* File will be written after @c n_packets_to_capture or call to pcap_write (&amp;pcap).
*
*/
/**
* @brief Close PCAP file
*
* @return rc - clib_error_t
*
*/
clib_error_t *
pcap_close (pcap_main_t * pm)
{
close (pm->file_descriptor);
pm->flags &= ~PCAP_MAIN_INIT_DONE;
pm->file_descriptor = -1;
return 0;
}
/**
* @brief Write PCAP file
*
* @return rc - clib_error_t
*
*/
clib_error_t *
pcap_write (pcap_main_t * pm)
{
clib_error_t *error = 0;
if (!(pm->flags & PCAP_MAIN_INIT_DONE))
{
pcap_file_header_t fh;
int n;
if (!pm->file_name)
pm->file_name = "/tmp/vnet.pcap";
pm->file_descriptor =
open (pm->file_name, O_CREAT | O_TRUNC | O_WRONLY, 0664);
if (pm->file_descriptor < 0)
{
error =
clib_error_return_unix (0, "failed to open `%s'", pm->file_name);
goto done;
}
pm->flags |= PCAP_MAIN_INIT_DONE;
pm->n_packets_captured = 0;
pm->n_pcap_data_written = 0;
clib_spinlock_init (&pm->lock);
/* Write file header. */
clib_memset (&fh, 0, 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;
n = write (pm->file_descriptor, &fh, sizeof (fh));
if (n != sizeof (fh))
{
if (n < 0)
error =
clib_error_return_unix (0, "write file header `%s'",
pm->file_name);
else
error =
clib_error_return (0, "short write of file header `%s'",
pm->file_name);
goto done;
}
}
while (vec_len (pm->pcap_data) > pm->n_pcap_data_written)
{
int n = vec_len (pm->pcap_data) - pm->n_pcap_data_written;
n = write (pm->file_descriptor,
vec_elt_at_index (pm->pcap_data, pm->n_pcap_data_written),
n);
if (n < 0 && unix_error_is_fatal (errno))
{
error = clib_error_return_unix (0, "write `%s'", pm->file_name);
goto done;
}
pm->n_pcap_data_written += n;
}
if (pm->n_pcap_data_written >= vec_len (pm->pcap_data))
{
vec_reset_length (pm->pcap_data);
pm->n_pcap_data_written = 0;
}
if (pm->n_packets_captured >= pm->n_packets_to_capture)
pcap_close (pm);
done:
if (error)
{
if (pm->file_descriptor >= 0)
close (pm->file_descriptor);
}
return error;
}
/**
* @brief Read PCAP file
*
* @return rc - clib_error_t
*
*/
clib_error_t *
pcap_read (pcap_main_t * pm)
{
clib_error_t *error = 0;
int fd, need_swap, n;
pcap_file_header_t fh;
pcap_packet_header_t ph;
fd = open (pm->file_name, O_RDONLY);
if (fd < 0)
{
error = clib_error_return_unix (0, "open `%s'", pm->file_name);
goto done;
}
if (read (fd, &fh, sizeof (fh)) != sizeof (fh))
{
error =
clib_error_return_unix (0, "read file header `%s'", pm->file_name);
goto done;
}
need_swap = 0;
if (fh.magic == 0xd4c3b2a1)
{
need_swap = 1;
#define _(t,f) fh.f = clib_byte_swap_##t (fh.f);
foreach_pcap_file_header;
#undef _
}
if (fh.magic != 0xa1b2c3d4)
{
error = clib_error_return (0, "bad magic `%s'", pm->file_name);
goto done;
}
pm->min_packet_bytes = 0;
pm->max_packet_bytes = 0;
while ((n = read (fd, &ph, sizeof (ph))) != 0)
{
u8 *data;
u64 timestamp;
u32 timestamp_sec;
u32 timestamp_usec;
if (need_swap)
{
#define _(t,f) ph.f = clib_byte_swap_##t (ph.f);
foreach_pcap_packet_header;
#undef _
}
data = vec_new (u8, ph.n_bytes_in_packet);
if (read (fd, data, ph.n_packet_bytes_stored_in_file) !=
ph.n_packet_bytes_stored_in_file)
{
error = clib_error_return (0, "short read `%s'", pm->file_name);
goto done;
}
if (vec_len (pm->packets_read) == 0)
pm->min_packet_bytes = pm->max_packet_bytes = ph.n_bytes_in_packet;
else
{
pm->min_packet_bytes =
clib_min (pm->min_packet_bytes, ph.n_bytes_in_packet);
pm->max_packet_bytes =
clib_max (pm->max_packet_bytes, ph.n_bytes_in_packet);
}
timestamp_sec = ph.time_in_sec;
timestamp_usec = ph.time_in_usec;
timestamp = ((u64) timestamp_sec) * 1000000 + (u64) timestamp_usec;
vec_add1 (pm->packets_read, data);
vec_add1 (pm->timestamps, timestamp);
}
done:
if (fd >= 0)
close (fd);
return error;
}
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/