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managed_components/espressif__pcap/src/pcap.c
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/*
* SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include "esp_log.h"
#include "esp_check.h"
#include "pcap.h"
static const char *TAG = "pcap";
#define PCAP_MAGIC_BIG_ENDIAN 0xA1B2C3D4 /*!< Big-Endian */
#define PCAP_MAGIC_LITTLE_ENDIAN 0xD4C3B2A1 /*!< Little-Endian */
typedef struct pcap_file_t pcap_file_t;
/**
* @brief Pcap File Header
*
*/
typedef struct {
uint32_t magic; /*!< Magic Number */
uint16_t major; /*!< Major Version */
uint16_t minor; /*!< Minor Version */
uint32_t zone; /*!< Time Zone Offset */
uint32_t sigfigs; /*!< Timestamp Accuracy */
uint32_t snaplen; /*!< Max Length to Capture */
uint32_t link_type; /*!< Link Layer Type */
} pcap_file_header_t;
/**
* @brief Pcap Packet Header
*
*/
typedef struct {
uint32_t seconds; /*!< Number of seconds since January 1st, 1970, 00:00:00 GMT */
uint32_t microseconds; /*!< Number of microseconds when the packet was captured (offset from seconds) */
uint32_t capture_length; /*!< Number of bytes of captured data, no longer than packet_length */
uint32_t packet_length; /*!< Actual length of current packet */
} pcap_packet_header_t;
/**
* @brief Pcap Runtime Handle
*
*/
struct pcap_file_t {
FILE *file; /*!< File handle */
pcap_link_type_t link_type; /*!< Pcap Link Type */
unsigned int major_version; /*!< Pcap version: major */
unsigned int minor_version; /*!< Pcap version: minor */
unsigned int time_zone; /*!< Pcap timezone code */
uint32_t endian_magic; /*!< Magic value related to endian format */
};
esp_err_t pcap_new_session(const pcap_config_t *config, pcap_file_handle_t *ret_pcap)
{
esp_err_t ret = ESP_OK;
pcap_file_t *pcap = NULL;
ESP_GOTO_ON_FALSE(config && ret_pcap, ESP_ERR_INVALID_ARG, err, TAG, "invalid argument");
ESP_GOTO_ON_FALSE(config->fp, ESP_ERR_INVALID_ARG, err, TAG, "pcap file handle can't be NULL");
pcap = calloc(1, sizeof(pcap_file_t));
ESP_GOTO_ON_FALSE(pcap, ESP_ERR_NO_MEM, err, TAG, "no mem for pcap file object");
pcap->file = config->fp;
pcap->major_version = config->major_version;
pcap->minor_version = config->minor_version;
pcap->endian_magic = config->flags.little_endian ? PCAP_MAGIC_LITTLE_ENDIAN : PCAP_MAGIC_BIG_ENDIAN;
pcap->time_zone = config->time_zone;
*ret_pcap = pcap;
return ret;
err:
if (pcap) {
free(pcap);
}
return ret;
}
esp_err_t pcap_del_session(pcap_file_handle_t pcap)
{
ESP_RETURN_ON_FALSE(pcap, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
if (pcap->file) {
fclose(pcap->file);
pcap->file = NULL;
}
free(pcap);
return ESP_OK;
}
esp_err_t pcap_write_header(pcap_file_handle_t pcap, pcap_link_type_t link_type)
{
ESP_RETURN_ON_FALSE(pcap, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
/* Write Pcap File header */
pcap_file_header_t header = {
.magic = pcap->endian_magic,
.major = pcap->major_version,
.minor = pcap->minor_version,
.zone = pcap->time_zone,
.sigfigs = 0,
.snaplen = 0x40000,
.link_type = link_type,
};
size_t real_write = fwrite(&header, sizeof(header), 1, pcap->file);
ESP_RETURN_ON_FALSE(real_write == 1, ESP_FAIL, TAG, "write pcap file header failed");
/* Save the link type to pcap file object */
pcap->link_type = link_type;
/* Flush content in the buffer into device */
fflush(pcap->file);
return ESP_OK;
}
esp_err_t pcap_capture_packet(pcap_file_handle_t pcap, void *payload, uint32_t length, uint32_t seconds, uint32_t microseconds)
{
ESP_RETURN_ON_FALSE(pcap && payload, ESP_ERR_INVALID_ARG, TAG, "invalid argumnet");
size_t real_write = 0;
pcap_packet_header_t header = {
.seconds = seconds,
.microseconds = microseconds,
.capture_length = length,
.packet_length = length
};
real_write = fwrite(&header, sizeof(header), 1, pcap->file);
ESP_RETURN_ON_FALSE(real_write == 1, ESP_FAIL, TAG, "write packet header failed");
real_write = fwrite(payload, sizeof(uint8_t), length, pcap->file);
ESP_RETURN_ON_FALSE(real_write == length, ESP_FAIL, TAG, "write packet payload failed");
/* Flush content in the buffer into device */
fflush(pcap->file);
return ESP_OK;
}
esp_err_t pcap_print_summary(pcap_file_handle_t pcap, FILE *print_file)
{
esp_err_t ret = ESP_OK;
long size = 0;
char *packet_payload = NULL;
ESP_RETURN_ON_FALSE(pcap && print_file, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
// get file size
fseek(pcap->file, 0L, SEEK_END);
size = ftell(pcap->file);
fseek(pcap->file, 0L, SEEK_SET);
// file empty is allowed, so return ESP_OK
ESP_RETURN_ON_FALSE(size, ESP_OK, TAG, "pcap file is empty");
// packet index (by bytes)
uint32_t index = 0;
pcap_file_header_t file_header;
size_t real_read = fread(&file_header, sizeof(pcap_file_header_t), 1, pcap->file);
ESP_RETURN_ON_FALSE(real_read == 1, ESP_FAIL, TAG, "read pcap file header failed");
index += sizeof(pcap_file_header_t);
//print pcap header information
fprintf(print_file, "------------------------------------------------------------------------\n");
fprintf(print_file, "Pcap packet Head:\n");
fprintf(print_file, "------------------------------------------------------------------------\n");
fprintf(print_file, "Magic Number: %"PRIx32"\n", file_header.magic);
fprintf(print_file, "Major Version: %d\n", file_header.major);
fprintf(print_file, "Minor Version: %d\n", file_header.minor);
fprintf(print_file, "SnapLen: %"PRIu32"\n", file_header.snaplen);
fprintf(print_file, "LinkType: %"PRIu32"\n", file_header.link_type);
fprintf(print_file, "------------------------------------------------------------------------\n");
uint32_t packet_num = 0;
pcap_packet_header_t packet_header;
while (index < size) {
real_read = fread(&packet_header, sizeof(pcap_packet_header_t), 1, pcap->file);
ESP_GOTO_ON_FALSE(real_read == 1, ESP_FAIL, err, TAG, "read pcap packet header failed");
// print packet header information
fprintf(print_file, "Packet %"PRIu32":\n", packet_num);
fprintf(print_file, "Timestamp (Seconds): %"PRIu32"\n", packet_header.seconds);
fprintf(print_file, "Timestamp (Microseconds): %"PRIu32"\n", packet_header.microseconds);
fprintf(print_file, "Capture Length: %"PRIu32"\n", packet_header.capture_length);
fprintf(print_file, "Packet Length: %"PRIu32"\n", packet_header.packet_length);
size_t payload_length = packet_header.capture_length;
packet_payload = malloc(payload_length);
ESP_GOTO_ON_FALSE(packet_payload, ESP_ERR_NO_MEM, err, TAG, "no mem to save packet payload");
real_read = fread(packet_payload, payload_length, 1, pcap->file);
ESP_GOTO_ON_FALSE(real_read == 1, ESP_FAIL, err, TAG, "read payload error");
// print packet information
if (file_header.link_type == PCAP_LINK_TYPE_802_11) {
// Frame Control Field is coded as LSB first
fprintf(print_file, "Frame Type: %2x\n", (packet_payload[0] >> 2) & 0x03);
fprintf(print_file, "Frame Subtype: %2x\n", (packet_payload[0] >> 4) & 0x0F);
fprintf(print_file, "Destination: ");
for (int j = 0; j < 5; j++) {
fprintf(print_file, "%2x ", packet_payload[4 + j]);
}
fprintf(print_file, "%2x\n", packet_payload[9]);
fprintf(print_file, "Source: ");
for (int j = 0; j < 5; j++) {
fprintf(print_file, "%2x ", packet_payload[10 + j]);
}
fprintf(print_file, "%2x\n", packet_payload[15]);
fprintf(print_file, "------------------------------------------------------------------------\n");
} else if (file_header.link_type == PCAP_LINK_TYPE_ETHERNET) {
fprintf(print_file, "Destination: ");
for (int j = 0; j < 5; j++) {
fprintf(print_file, "%2x ", packet_payload[j]);
}
fprintf(print_file, "%2x\n", packet_payload[5]);
fprintf(print_file, "Source: ");
for (int j = 0; j < 5; j++) {
fprintf(print_file, "%2x ", packet_payload[6 + j]);
}
fprintf(print_file, "%2x\n", packet_payload[11]);
fprintf(print_file, "Type: 0x%x\n", packet_payload[13] | (packet_payload[12] << 8));
fprintf(print_file, "------------------------------------------------------------------------\n");
} else {
fprintf(print_file, "Unknown link type:%"PRIu32"\n", file_header.link_type);
fprintf(print_file, "------------------------------------------------------------------------\n");
}
free(packet_payload);
packet_payload = NULL;
index += packet_header.capture_length + sizeof(pcap_packet_header_t);
packet_num ++;
}
fprintf(print_file, "Pcap packet Number: %"PRIu32"\n", packet_num);
fprintf(print_file, "------------------------------------------------------------------------\n");
return ret;
err:
if (packet_payload) {
free(packet_payload);
}
return ret;
}
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