pcap.c

 
#include <freerdp/config.h>
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#include <winpr/wtypes.h>
#include <winpr/assert.h>
#include <winpr/file.h>
#include <winpr/crt.h>
#include <winpr/sysinfo.h>
 
#include <freerdp/types.h>
#include <freerdp/utils/pcap.h>
 
#define PCAP_MAGIC 0xA1B2C3D4
 
struct rdp_pcap
{
  FILE* fp;
  char* name;
  BOOL write;
  INT64 file_size;
  size_t record_count;
  pcap_header header;
  pcap_record* head;
  pcap_record* tail;
  pcap_record* record;
};
 
static BOOL pcap_read_header(rdpPcap* pcap, pcap_header* header)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(header);
 
  return fread(header, sizeof(pcap_header), 1, pcap->fp) == 1;
}
 
static BOOL pcap_write_header(rdpPcap* pcap, const pcap_header* header)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(header);
 
  return fwrite(header, sizeof(pcap_header), 1, pcap->fp) == 1;
}
 
static BOOL pcap_read_record_header(rdpPcap* pcap, pcap_record_header* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  return fread(record, sizeof(pcap_record_header), 1, pcap->fp) == 1;
}
 
static BOOL pcap_write_record_header(rdpPcap* pcap, const pcap_record_header* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  return fwrite(record, sizeof(pcap_record_header), 1, pcap->fp) == 1;
}
 
static BOOL pcap_read_record(rdpPcap* pcap, pcap_record* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  if (!pcap_read_record_header(pcap, &record->header))
    return FALSE;
 
  record->length = record->header.incl_len;
  record->data = malloc(record->length);
  if (!record->data)
    return FALSE;
 
  if (fread(record->data, record->length, 1, pcap->fp) != 1)
  {
    free(record->data);
    record->data = nullptr;
    return FALSE;
  }
  return TRUE;
}
 
static BOOL pcap_write_record(rdpPcap* pcap, const pcap_record* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  return pcap_write_record_header(pcap, &record->header) &&
         (fwrite(record->cdata, record->length, 1, pcap->fp) == 1);
}
 
BOOL pcap_add_record(rdpPcap* pcap, const void* data, size_t length)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(data || (length == 0));
  WINPR_ASSERT(length <= UINT32_MAX);
 
  pcap_record* record = (pcap_record*)calloc(1, sizeof(pcap_record));
  if (!record)
    return FALSE;
 
  record->cdata = data;
  record->length = (UINT32)length;
  record->header.incl_len = (UINT32)length;
  record->header.orig_len = (UINT32)length;
 
  const UINT64 ns = winpr_GetUnixTimeNS();
 
  record->header.ts_sec = (UINT32)WINPR_TIME_NS_TO_S(ns);
  record->header.ts_usec = (UINT32)WINPR_TIME_NS_REM_US(ns);
 
  if (pcap->tail == nullptr)
  {
    pcap->tail = record;
    if (!pcap->tail)
      return FALSE;
 
    pcap->head = pcap->tail;
  }
  else
  {
    record->next = pcap->tail;
    pcap->tail = record;
  }
 
  if (pcap->record == nullptr)
    pcap->record = record;
 
  return TRUE;
}
 
BOOL pcap_has_next_record(const rdpPcap* pcap)
{
  WINPR_ASSERT(pcap);
 
  return (pcap->file_size - (_ftelli64(pcap->fp)) > 16);
}
 
BOOL pcap_get_next_record_header(rdpPcap* pcap, pcap_record* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  if (pcap_has_next_record(pcap) != TRUE)
    return FALSE;
 
  pcap_read_record_header(pcap, &record->header);
  record->length = record->header.incl_len;
 
  return TRUE;
}
 
BOOL pcap_get_next_record_content(rdpPcap* pcap, pcap_record* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  return fread(record->data, record->length, 1, pcap->fp) == 1;
}
 
BOOL pcap_get_next_record(rdpPcap* pcap, pcap_record* record)
{
  WINPR_ASSERT(pcap);
  WINPR_ASSERT(record);
 
  return pcap_has_next_record(pcap) && pcap_read_record(pcap, record);
}
 
rdpPcap* pcap_open(const char* name, BOOL write)
{
  WINPR_ASSERT(name);
 
  rdpPcap* pcap = (rdpPcap*)calloc(1, sizeof(rdpPcap));
  if (!pcap)
    goto fail;
 
  pcap->name = _strdup(name);
  pcap->write = write;
  pcap->record_count = 0;
  pcap->fp = winpr_fopen(name, write ? "w+b" : "rb");
 
  if (pcap->fp == nullptr)
    goto fail;
 
  if (write)
  {
    pcap->header.magic_number = PCAP_MAGIC;
    pcap->header.version_major = 2;
    pcap->header.version_minor = 4;
    pcap->header.thiszone = 0;
    pcap->header.sigfigs = 0;
    pcap->header.snaplen = UINT32_MAX;
    pcap->header.network = 0;
    if (!pcap_write_header(pcap, &pcap->header))
      goto fail;
  }
  else
  {
    (void)_fseeki64(pcap->fp, 0, SEEK_END);
    pcap->file_size = _ftelli64(pcap->fp);
    (void)_fseeki64(pcap->fp, 0, SEEK_SET);
    if (!pcap_read_header(pcap, &pcap->header))
      goto fail;
  }
 
  return pcap;
 
fail:
  pcap_close(pcap);
  return nullptr;
}
 
void pcap_flush(rdpPcap* pcap)
{
  WINPR_ASSERT(pcap);
 
  while (pcap->record != nullptr)
  {
    (void)pcap_write_record(pcap, pcap->record);
    pcap->record = pcap->record->next;
  }
 
  if (pcap->fp != nullptr)
    (void)fflush(pcap->fp);
}
 
void pcap_close(rdpPcap* pcap)
{
  if (!pcap)
    return;
 
  pcap_flush(pcap);
 
  if (pcap->fp != nullptr)
    (void)fclose(pcap->fp);
 
  free(pcap->name);
  free(pcap);
}