/*
* compress_file
*
* Compresses the stream fin into foutname. This code is shamelessly
* copied from libpcap's savefile.c:sf_next_packet()
*
* Inputs:
* - fin: the uncompressed input stream
* - lfout: the compressed output stream
* - filehdr: the file header
* - swapped: whether the packet order is swapped compared to the host order
*
* Output:
* - return: 0 if ok, <0 if there was any problem
*
*/
int compress_file (FILE *fin, lFILE *lfout, struct pcap_file_header *filehdr,
int swapped)
{
codec_t *codec;
int size;
int hdr_size;
u_char buffer[MAXDATABUFFER];
struct pcap_pkthdr pkthdr;
int result;
u_char *comp_pkt;
int comp_len;
u_int32_t bytes_written;
co_t co;
int paddings;
/* get header size */
hdr_size = pktd_get_hdr_size (filehdr->linktype);
/* create and initialize codec */
codec = create_codec();
/* get compression parameters */
co.rm_offset = DEFAULT_PKTD_COMPRESSION_RESTART_MARKER;
co.ip_mask = DEFAULT_PKTD_COMPRESSION_IP_MASK;
co.tcp_mask = DEFAULT_PKTD_COMPRESSION_TCP_MASK;
co.udp_mask = DEFAULT_PKTD_COMPRESSION_UDP_MASK;
/* write the new extended pcap header */
if (pktd_lfwrite_ext_header (lfout, 40, DLT_COMPRESSED, &co, NULL) < 0) {
fprintf (stderr, "Error: cannot write header in file %s\n", foutname);
return -1;
}
bytes_written = 0;
while (1) {
/* read the pcap header */
size = TCPDUMP_PACKET_HEADER_LENGTH;
result = fread (&pkthdr, 1, size, fin);
if (result != size) {
if ((result == 0) && (feof (fin))) {
break;
}
fprintf (stderr, "Error: fread'ing file %s\n", finname);
return -1;
}
/* encode_trace requires pkthdr in host order */
if (swapped) {
pktd_swap_pkthdr (&pkthdr);
}
/* The caplen and len fields were interchanged at version 2.3,
* in order to match the bpf header layout. But unfortunately
* some files were written with version 2.3 in their headers
* but without the interchanged fields */
if (filehdr->version_minor < 3 ||
(filehdr->version_minor == 3 && pkthdr.caplen > pkthdr.len)) {
int t = pkthdr.caplen;
pkthdr.caplen = pkthdr.len;
pkthdr.len = t;
}
/* read the packet itself */
size = pkthdr.caplen;
result = fread (buffer, 1, size, fin);
if (result != size) {
if ((result == 0) && (feof (fin))) {
break;
}
fprintf (stderr, "Error: freading file %s\n", finname);
return -1;
}
/* encode_trace requires packet in network order, so no swap is needed */
/* encode the packet */
encode_trace (codec, &co, &pkthdr, buffer, pkthdr.caplen, hdr_size,
&comp_pkt, &comp_len);
/* introduce restart markers if needed */
if (co.rm_offset != 0) {
paddings = need_restart_markers (&co, lfout, comp_len, bytes_written,
codec);
if (paddings < 0) {
return -1;
} else if (paddings > 0) {
bytes_written += paddings;
/* there was a codec initialization => must reencode packet */
encode_trace (codec, &co, &pkthdr, buffer, pkthdr.caplen, hdr_size,
&comp_pkt, &comp_len);
}
}
/* write compressed packet to file */
if (lfwrite (lfout, comp_pkt, comp_len) < comp_len) {
return -1;
}
}
return 0;
}
int MyQtFile::myfwrite(QString &buffersize)
{
return lfwrite(fdQfile, buffersize.toLatin1().data(), buffersize.size());
}
/*
* uncompress_file
*
* Uncompresses the stream fin into foutname
*
* Inputs:
* - fin: the compressed input stream
* - lfout: the uncompressed output stream
* - co: compression parameters
*
* Output:
* - return: 0 if ok, <0 if there was any problem
*
*/
int uncompress_file (FILE *fin, lFILE *lfout, co_t *co)
{
codec_t *codec;
int size;
u_char compressed_buffer[MAX_COMPRESSED_LENGTH];
u_char buffer[MAXDATABUFFER];
struct pcap_pkthdr pkthdr;
int result;
/* create and initialize codec */
codec = create_codec();
/* write the new header */
if (pktd_write_header (lfileno(lfout), 40, DLT_RAW) < 0) {
fprintf (stderr, "Error: cannot write header in file %s\n", foutname);
return -1;
}
/*
* every time you seek the rm_offset, you *must* initialize the codec
(void)fseek (fin, co->rm_offset, SEEK_CUR);
init_codec (codec);
*/
/* parse traces */
while (1) {
/* read the trace length */
size = TCPDUMP_PACKET_HEADER_LENGTH_COMPRESSED;
result = fread (compressed_buffer, 1, size, fin);
if (result != size) {
if ((result == 0) && (feof (fin))) {
break;
}
fprintf (stderr, "Error: fread'ing file %s\n", finname);
return -1;
}
size = (u_int8_t)(compressed_buffer[0]);
/* look for escaped packets */
if (size == COMPRESSION_INIT_CODEC) {
/* codec initialization requested */
init_codec (codec);
continue;
} else if (size == COMPRESSION_PADDING) {
/* padding (empty) trace */
continue;
}
/* get the rest of the compressed packet */
result = fread (compressed_buffer+TCPDUMP_PACKET_HEADER_LENGTH_COMPRESSED,
1, size-TCPDUMP_PACKET_HEADER_LENGTH_COMPRESSED, fin);
if (result != (size-TCPDUMP_PACKET_HEADER_LENGTH_COMPRESSED)) {
if ((size == 0) && (feof (fin))) {
break;
}
fprintf (stderr, "Error: freading file %s (%i)\n", finname, size);
return -1;
}
/* decode the packet */
size = decode_trace (codec, compressed_buffer, &pkthdr, buffer);
if (size < 0) {
fprintf (stderr, "Error: decoding trace\n");
return -1;
}
/* write the uncompressed packet */
/*
result = fwrite(buffer, 1, size, fout);
*/
result = lfwrite(lfout, buffer, size);
if (result != size) {
fprintf (stderr, "Error: fwriting file %s\n", foutname);
return -1;
}
}
return 0;
}
