diff options
Diffstat (limited to 'src/vppinfra/mpcap.c')
| -rw-r--r-- | src/vppinfra/mpcap.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/vppinfra/mpcap.c b/src/vppinfra/mpcap.c new file mode 100644 index 00000000000..902f52f1870 --- /dev/null +++ b/src/vppinfra/mpcap.c @@ -0,0 +1,247 @@ +/* + * 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/vnet.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; + + if (stat (pm->file_name, &statb) < 0) + { + error = clib_error_return_unix (0, "stat `%s'", pm->file_name); + goto done; + } + + fd = open (pm->file_name, O_RDONLY); + if (fd < 0) + { + error = clib_error_return_unix (0, "open `%s'", 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); + 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: + */ |