srsLTE源码学习：抓包pcap.h（packet capture）
Table of Contents
pcap.h
packet capture
pcap.h
lib\include\srslte\common 14040 4/10/2019 182
/**
*
* \section COPYRIGHT
*
* Copyright 2013-2015 Software Radio Systems Limited
*
* \section LICENSE
*
* This file is part of the srsUE library.
*
* srsUE is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* srsUE is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* A copy of the GNU Affero General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
* packet capture
*/
#ifndef SRSLTE_PCAP_H
#define SRSLTE_PCAP_H
//packet capture
#include
#include
#include
#include
#define MAC_LTE_DLT 147
#define NAS_LTE_DLT 148
#define RLC_LTE_DLT 149 // UDP needs to be selected as protocol
#define S1AP_LTE_DLT 150
/* This structure gets written to the start of the file */
typedef struct pcap_hdr_s {
unsigned int magic_number; /* magic number */
unsigned short version_major; /* major version number */
unsigned short version_minor; /* minor version number */
unsigned int thiszone; /* GMT to local correction */
unsigned int sigfigs; /* accuracy of timestamps */
unsigned int snaplen; /* max length of captured packets, in octets */
unsigned int network; /* data link type */
} pcap_hdr_t;
/* This structure precedes each packet */
typedef struct pcaprec_hdr_s {
unsigned int ts_sec; /* timestamp seconds */
unsigned int ts_usec; /* timestamp microseconds */
unsigned int incl_len; /* number of octets of packet saved in file */
unsigned int orig_len; /* actual length of packet */
} pcaprec_hdr_t;
/* radioType */
#define FDD_RADIO 1
#define TDD_RADIO 2
/* Direction */
#define DIRECTION_UPLINK 0
#define DIRECTION_DOWNLINK 1
/* rntiType */
#define NO_RNTI 0 /* Used for BCH-BCH */
#define P_RNTI 1
#define RA_RNTI 2
#define C_RNTI 3
#define SI_RNTI 4
#define SPS_RNTI 5
#define M_RNTI 6
#define MAC_LTE_START_STRING "mac-lte"
#define MAC_LTE_PAYLOAD_TAG 0x01
#define MAC_LTE_RNTI_TAG 0x02
#define MAC_LTE_UEID_TAG 0x03
#define MAC_LTE_FRAME_SUBFRAME_TAG 0x04
#define MAC_LTE_PREDFINED_DATA_TAG 0x05
#define MAC_LTE_RETX_TAG 0x06
#define MAC_LTE_CRC_STATUS_TAG 0x07
/* Context information for every MAC PDU that will be logged */
typedef struct MAC_Context_Info_t {
unsigned short radioType;
unsigned char direction;
unsigned char rntiType;
unsigned short rnti;
unsigned short ueid;
unsigned char isRetx;
unsigned char crcStatusOK;
unsigned short sysFrameNumber;
unsigned short subFrameNumber;
} MAC_Context_Info_t;
/* Context information for every NAS PDU that will be logged */
typedef struct NAS_Context_Info_s {
// No Context yet
} NAS_Context_Info_t;
/* RLC-LTE disector */
/* rlcMode
RLC 无线链路控制协议RLC
RRC（Radio Resource Control）是指无线资源控制
*/
#define RLC_TM_MODE 1
#define RLC_UM_MODE 2
#define RLC_AM_MODE 4
#define RLC_PREDEF 8
/* priority ? */
/* channelType */
#define CHANNEL_TYPE_CCCH 1
#define CHANNEL_TYPE_BCCH_BCH 2
#define CHANNEL_TYPE_PCCH 3
#define CHANNEL_TYPE_SRB 4
#define CHANNEL_TYPE_DRB 5
#define CHANNEL_TYPE_BCCH_DL_SCH 6
#define CHANNEL_TYPE_MCCH 7
#define CHANNEL_TYPE_MTCH 8
/* sequenceNumberLength */
#define UM_SN_LENGTH_5_BITS 5
#define UM_SN_LENGTH_10_BITS 10
#define AM_SN_LENGTH_10_BITS 10
#define AM_SN_LENGTH_16_BITS 16
/* Narrow band mode */
typedef enum {
rlc_no_nb_mode = 0,
rlc_nb_mode = 1
} rlc_lte_nb_mode;
/* Context information for every RLC PDU that will be logged */
typedef struct {
unsigned char rlcMode;
unsigned char direction;
unsigned char priority;
unsigned char sequenceNumberLength;
unsigned short ueid;
unsigned short channelType;
unsigned short channelId; /* for SRB: 1=SRB1, 2=SRB2, 3=SRB1bis; for DRB: DRB ID */
unsigned short pduLength;
bool extendedLiField;
rlc_lte_nb_mode nbMode;
} RLC_Context_Info_t;
// See Wireshark's packet-rlc-lte.h for details
#define RLC_LTE_START_STRING "rlc-lte"
#define RLC_LTE_SN_LENGTH_TAG 0x02
#define RLC_LTE_DIRECTION_TAG 0x03
#define RLC_LTE_PRIORITY_TAG 0x04
#define RLC_LTE_UEID_TAG 0x05
#define RLC_LTE_CHANNEL_TYPE_TAG 0x06
#define RLC_LTE_CHANNEL_ID_TAG 0x07
#define RLC_LTE_EXT_LI_FIELD_TAG 0x08
#define RLC_LTE_NB_MODE_TAG 0x09
#define RLC_LTE_PAYLOAD_TAG 0x01
/* Context information for every S1AP PDU that will be logged */
typedef struct S1AP_Context_Info_s {
// No Context yet
} S1AP_Context_Info_t;
/**************************************************************************
* API functions for opening/closing LTE PCAP files *
**************************************************************************/
/* Open the file and write file header */
inline FILE *LTE_PCAP_Open(uint32_t DLT, const char *fileName)
{
pcap_hdr_t file_header =
{
0xa1b2c3d4, /* magic number */
2, 4, /* version number is 2.4 */
0, /* timezone */
0, /* sigfigs - apparently all tools do this */
65535, /* snaplen - this should be long enough */
DLT /* Data Link Type (DLT). Set as unused value 147 for now */
};
FILE *fd = fopen(fileName, "w");
if (fd == NULL) {
printf("Failed to open file \"%s\" for writing\n", fileName);
return NULL;
}
/* Write the file header */
fwrite(&file_header, sizeof(pcap_hdr_t), 1, fd);
return fd;
}
/* Close the PCAP file */
inline void LTE_PCAP_Close(FILE *fd)
{
if(fd)
fclose(fd);
}
/**************************************************************************
* API functions for writing MAC-LTE PCAP files *
**************************************************************************/
/* Write an individual PDU (PCAP packet header + mac-context + mac-pdu) */
inline int LTE_PCAP_MAC_WritePDU(FILE *fd, MAC_Context_Info_t *context,
const unsigned char *PDU, unsigned int length)
{
pcaprec_hdr_t packet_header;
char context_header[256];
int offset = 0;
uint16_t tmp16;
/* Can't write if file wasn't successfully opened */
if (fd == NULL) {
printf("Error: Can't write to empty file handle\n");
return 0;
}
/*****************************************************************/
/* Context information (same as written by UDP heuristic clients */
context_header[offset++] = context->radioType;
context_header[offset++] = context->direction;
context_header[offset++] = context->rntiType;
/* RNTI */
context_header[offset++] = MAC_LTE_RNTI_TAG;
tmp16 = htons(context->rnti);
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
/* UEId */
context_header[offset++] = MAC_LTE_UEID_TAG;
tmp16 = htons(context->ueid);
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
/* Subframe Number and System Frame Number */
/* SFN is stored in 12 MSB and SF in 4 LSB */
context_header[offset++] = MAC_LTE_FRAME_SUBFRAME_TAG;
tmp16 = (context->sysFrameNumber << 4) | context->subFrameNumber;
tmp16 = htons(tmp16);
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
/* CRC Status */
context_header[offset++] = MAC_LTE_CRC_STATUS_TAG;
context_header[offset++] = context->crcStatusOK;
/* Data tag immediately preceding PDU */
context_header[offset++] = MAC_LTE_PAYLOAD_TAG;
/****************************************************************/
/* PCAP Header */
struct timeval t;
gettimeofday(&t, NULL);
packet_header.ts_sec = t.tv_sec;
packet_header.ts_usec = t.tv_usec;
packet_header.incl_len = offset + length;
packet_header.orig_len = offset + length;
/***************************************************************/
/* Now write everything to the file */
fwrite(&packet_header, sizeof(pcaprec_hdr_t), 1, fd);
fwrite(context_header, 1, offset, fd);
fwrite(PDU, 1, length, fd);
return 1;
}
/**************************************************************************
* API functions for writing NAS-EPS PCAP files *
**************************************************************************/
/* Write an individual PDU (PCAP packet header + nas-context + nas-pdu) */
inline int LTE_PCAP_NAS_WritePDU(FILE *fd, NAS_Context_Info_t *context,
const unsigned char *PDU, unsigned int length)
{
pcaprec_hdr_t packet_header;
/* Can't write if file wasn't successfully opened */
if (fd == NULL) {
printf("Error: Can't write to empty file handle\n");
return 0;
}
/****************************************************************/
/* PCAP Header */
struct timeval t;
gettimeofday(&t, NULL);
packet_header.ts_sec = t.tv_sec;
packet_header.ts_usec = t.tv_usec;
packet_header.incl_len = length;
packet_header.orig_len = length;
/***************************************************************/
/* Now write everything to the file */
fwrite(&packet_header, sizeof(pcaprec_hdr_t), 1, fd);
fwrite(PDU, 1, length, fd);
return 1;
}
/**************************************************************************
* API functions for writing RLC-LTE PCAP files *
**************************************************************************/
/* Write an individual RLC PDU (PCAP packet header + UDP header + rlc-context + rlc-pdu) */
inline int LTE_PCAP_RLC_WritePDU(FILE *fd, RLC_Context_Info_t *context,
const unsigned char *PDU, unsigned int length)
{
pcaprec_hdr_t packet_header;
char context_header[256];
int offset = 0;
uint16_t tmp16;
/* Can't write if file wasn't successfully opened */
if (fd == NULL) {
printf("Error: Can't write to empty file handle\n");
return 0;
}
/*****************************************************************/
// Add dummy UDP header, start with src and dest port
context_header[offset++] = 0xde;
context_header[offset++] = 0xad;
context_header[offset++] = 0xbe;
context_header[offset++] = 0xef;
// length
tmp16 = length + 12;
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
// dummy CRC
context_header[offset++] = 0xde;
context_header[offset++] = 0xad;
// Start magic string
memcpy(&context_header[offset], RLC_LTE_START_STRING, strlen(RLC_LTE_START_STRING));
offset += strlen(RLC_LTE_START_STRING);
// Fixed field RLC mode
context_header[offset++] = context->rlcMode;
// Conditional fields
if (context->rlcMode == RLC_UM_MODE) {
context_header[offset++] = RLC_LTE_SN_LENGTH_TAG;
context_header[offset++] = context->sequenceNumberLength;
}
// Optional fields
context_header[offset++] = RLC_LTE_DIRECTION_TAG;
context_header[offset++] = context->direction;
context_header[offset++] = RLC_LTE_PRIORITY_TAG;
context_header[offset++] = context->priority;
context_header[offset++] = RLC_LTE_UEID_TAG;
tmp16 = htons(context->ueid);
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
context_header[offset++] = RLC_LTE_CHANNEL_TYPE_TAG;
tmp16 = htons(context->channelType);
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
context_header[offset++] = RLC_LTE_CHANNEL_ID_TAG;
tmp16 = htons(context->channelId);
memcpy(context_header+offset, &tmp16, 2);
offset += 2;
// Now the actual PDU
context_header[offset++] = RLC_LTE_PAYLOAD_TAG;
// PCAP header
struct timeval t;
gettimeofday(&t, NULL);
packet_header.ts_sec = t.tv_sec;
packet_header.ts_usec = t.tv_usec;
packet_header.incl_len = offset + length;
packet_header.orig_len = offset + length;
// Write everything to file
fwrite(&packet_header, sizeof(pcaprec_hdr_t), 1, fd);
fwrite(context_header, 1, offset, fd);
fwrite(PDU, 1, length, fd);
return 1;
}
/**************************************************************************
* API functions for writing S1AP PCAP files *
**************************************************************************/
/* Write an individual PDU (PCAP packet header + s1ap-context + s1ap-pdu) */
inline int LTE_PCAP_S1AP_WritePDU(FILE *fd, S1AP_Context_Info_t *context,
const unsigned char *PDU, unsigned int length)
{
pcaprec_hdr_t packet_header;
/* Can't write if file wasn't successfully opened */
if (fd == NULL) {
printf("Error: Can't write to empty file handle\n");
return 0;
}
/****************************************************************/
/* PCAP Header */
struct timeval t;
gettimeofday(&t, NULL);
packet_header.ts_sec = t.tv_sec;
packet_header.ts_usec = t.tv_usec;
packet_header.incl_len = length;
packet_header.orig_len = length;
/***************************************************************/
/* Now write everything to the file */
fwrite(&packet_header, sizeof(pcaprec_hdr_t), 1, fd);
fwrite(PDU, 1, length, fd);
return 1;
}
#endif // SRSLTE_PCAP_H