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-rw-r--r--vnet/vnet/unix/pcap.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/vnet/vnet/unix/pcap.c b/vnet/vnet/unix/pcap.c
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+++ b/vnet/vnet/unix/pcap.c
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+/*
+ * 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 <vnet/unix/pcap.h>
+#include <sys/fcntl.h>
+
+/* Usage
+
+#include <vnet/unix/pcap.h>
+
+static pcap_main_t pcap = {
+ .file_name = "/tmp/ip4",
+ .n_packets_to_capture = 2,
+ .packet_type = PCAP_PACKET_TYPE_ip,
+};
+
+To add a buffer:
+
+ pcap_add_buffer (&pcap, vm, pi0, 128);
+
+file will be written after n_packets_to_capture or call to pcap_write (&pcap).
+
+*/
+
+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;
+
+ /* Write file header. */
+ 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;
+ }
+ }
+
+ do {
+ int n = vec_len (pm->pcap_data) - pm->n_pcap_data_written;
+
+ if (n > 0)
+ {
+ 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);
+ break;
+ }
+ } while (pm->n_packets_captured >= pm->n_packets_to_capture);
+
+ if (pm->n_packets_captured >= pm->n_packets_to_capture)
+ {
+ close (pm->file_descriptor);
+ pm->flags &= ~PCAP_MAIN_INIT_DONE;
+ pm->file_descriptor = -1;
+ }
+
+ done:
+ if (error)
+ {
+ if (pm->file_descriptor >= 0)
+ close (pm->file_descriptor);
+ }
+ return error;
+}
+
+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;
+
+ 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);
+ }
+
+ vec_add1 (pm->packets_read, data);
+ }
+
+ done:
+ if (fd >= 0)
+ close (fd);
+ return error;
+
+}