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/*
* 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 <sys/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_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_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:
*/
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