2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
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12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * pcap.h: libpcap packet capture format
18 * Copyright (c) 2008 Eliot Dresselhaus
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21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
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41 * @brief PCAP utility definitions
43 #ifndef included_vnet_pcap_h
44 #define included_vnet_pcap_h
46 #include <vlib/vlib.h>
49 * @brief Packet types supported by PCAP
57 #define foreach_vnet_pcap_packet_type \
65 #define _(f,n) PCAP_PACKET_TYPE_##f = (n),
66 foreach_vnet_pcap_packet_type
70 #define foreach_pcap_file_header \
71 /** 0xa1b2c3d4 host byte order. \
72 0xd4c3b2a1 => need to byte swap everything. */ \
75 /** Currently major 2 minor 4. */ \
76 _ (u16, major_version) \
77 _ (u16, minor_version) \
82 /** Accuracy of timestamps. Typically set to 0. */ \
85 /** Size of largest packet in file. */ \
86 _ (u32, max_packet_size_in_bytes) \
88 /** One of vnet_pcap_packet_type_t. */ \
91 /** File header struct */
94 foreach_pcap_file_header
98 #define foreach_pcap_packet_header \
99 /** Time stamp in seconds */ \
100 _ (u32, time_in_sec) \
101 /** Time stamp in microseconds. */ \
102 _ (u32, time_in_usec) \
104 /** Number of bytes stored in file. */ \
105 _ (u32, n_packet_bytes_stored_in_file) \
106 /** Number of bytes in actual packet. */ \
107 _ (u32, n_bytes_in_packet)
109 /** Packet header. */
112 foreach_pcap_packet_header
115 /** Packet data follows. */
117 } pcap_packet_header_t;
120 * @brief PCAP main state data structure
123 /** File name of pcap output. */
126 /** Number of packets to capture. */
127 u32 n_packets_to_capture;
130 pcap_packet_type_t packet_type;
132 /** Number of packets currently captured. */
133 u32 n_packets_captured;
137 #define PCAP_MAIN_INIT_DONE (1 << 0)
139 /** File descriptor for reading/writing. */
143 u32 n_pcap_data_written;
145 /** Vector of pcap data. */
148 /** Packets read from file. */
151 /** Min/Max Packet bytes */
152 u32 min_packet_bytes, max_packet_bytes;
155 /** Write out data to output file. */
156 clib_error_t * pcap_write (pcap_main_t * pm);
158 /** Read data from file. */
159 clib_error_t * pcap_read (pcap_main_t * pm);
164 * @param *pm - pcap_main_t
165 * @param time_now - f64
166 * @param n_bytes_in_trace - u32
167 * @param n_bytes_in_packet - u32
169 * @return Packet Data
173 pcap_add_packet (pcap_main_t * pm,
175 u32 n_bytes_in_trace,
176 u32 n_bytes_in_packet)
178 pcap_packet_header_t * h;
181 vec_add2 (pm->pcap_data, d, sizeof (h[0]) + n_bytes_in_trace);
183 h->time_in_sec = time_now;
184 h->time_in_usec = 1e6*(time_now - h->time_in_sec);
185 h->n_packet_bytes_stored_in_file = n_bytes_in_trace;
186 h->n_bytes_in_packet = n_bytes_in_packet;
187 pm->n_packets_captured++;
192 * @brief Add buffer (vlib_buffer_t) to the trace
194 * @param *pm - pcap_main_t
195 * @param *vm - vlib_main_t
196 * @param buffer_index - u32
197 * @param n_bytes_in_trace - u32
201 pcap_add_buffer (pcap_main_t * pm,
202 vlib_main_t * vm, u32 buffer_index,
203 u32 n_bytes_in_trace)
205 vlib_buffer_t * b = vlib_get_buffer (vm, buffer_index);
206 u32 n = vlib_buffer_length_in_chain (vm, b);
207 i32 n_left = clib_min (n_bytes_in_trace, n);
208 f64 time_now = vlib_time_now (vm);
211 d = pcap_add_packet (pm, time_now, n_left, n);
214 u32 copy_length = clib_min ((u32) n_left, b->current_length);
215 clib_memcpy (d, b->data + b->current_data, copy_length);
216 n_left -= b->current_length;
219 d += b->current_length;
220 ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
221 b = vlib_get_buffer (vm, b->next_buffer);
224 /** Flush output vector. */
225 if (vec_len (pm->pcap_data) >= 64*1024
226 || pm->n_packets_captured >= pm->n_packets_to_capture)
230 #endif /* included_vnet_pcap_h */