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mpv/libmpdemux/pnm.c
rtognimp b5e683f42d "Fix" for pnm EOF detection (stop on read errors)
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@15078 b3059339-0415-0410-9bf9-f77b7e298cf2
2005-04-09 14:50:36 +00:00

858 lines
20 KiB
C

/*
* Copyright (C) 2000-2002 the xine project
*
* This file is part of xine, a free video player.
*
* xine is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* xine 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*
* $Id$
*
* pnm protocol implementation
* based upon code from joschka
*/
#include <unistd.h>
#include <stdio.h>
#include <assert.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/time.h>
#include <inttypes.h>
#include "config.h"
#ifndef HAVE_WINSOCK2
#define closesocket close
#include <sys/socket.h>
//#include <netinet/in.h>
//#include <netdb.h>
#else
#include <winsock2.h>
#endif
#include "pnm.h"
//#include "libreal/rmff.h"
#define FOURCC_TAG( ch0, ch1, ch2, ch3 ) \
(((long)(unsigned char)(ch3) ) | \
( (long)(unsigned char)(ch2) << 8 ) | \
( (long)(unsigned char)(ch1) << 16 ) | \
( (long)(unsigned char)(ch0) << 24 ) )
#define RMF_TAG FOURCC_TAG('.', 'R', 'M', 'F')
#define PROP_TAG FOURCC_TAG('P', 'R', 'O', 'P')
#define MDPR_TAG FOURCC_TAG('M', 'D', 'P', 'R')
#define CONT_TAG FOURCC_TAG('C', 'O', 'N', 'T')
#define DATA_TAG FOURCC_TAG('D', 'A', 'T', 'A')
#define INDX_TAG FOURCC_TAG('I', 'N', 'D', 'X')
#define PNA_TAG FOURCC_TAG('P', 'N', 'A', 0 )
/*
#define LOG
*/
#define BUF_SIZE 4096
#define HEADER_SIZE 4096
struct pnm_s {
int s;
// char *host;
// int port;
char *path;
// char *url;
char buffer[BUF_SIZE]; /* scratch buffer */
/* receive buffer */
uint8_t recv[BUF_SIZE];
int recv_size;
int recv_read;
uint8_t header[HEADER_SIZE];
int header_len;
int header_read;
unsigned int seq_num[4]; /* two streams with two indices */
unsigned int seq_current[2]; /* seqs of last stream chunk read */
uint32_t ts_current; /* timestamp of current chunk */
uint32_t ts_last[2]; /* timestamps of last chunks */
unsigned int packet; /* number of last recieved packet */
};
/*
* utility macros
*/
#define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
#define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \
(((uint8_t*)(x))[1] << 16) | \
(((uint8_t*)(x))[2] << 8) | \
((uint8_t*)(x))[3])
/* D means direct (no pointer) */
#define BE_16D(x) ((x & 0xff00) >> 8)|((x & 0x00ff) << 8)
/* sizes */
#define PREAMBLE_SIZE 8
#define CHECKSUM_SIZE 3
/* header of rm files */
#define RM_HEADER_SIZE 0x12
const unsigned char rm_header[]={
0x2e, 0x52, 0x4d, 0x46, /* object_id ".RMF" */
0x00, 0x00, 0x00, 0x12, /* header_size 0x12 */
0x00, 0x00, /* object_version 0x00 */
0x00, 0x00, 0x00, 0x00, /* file_version 0x00 */
0x00, 0x00, 0x00, 0x06 /* num_headers 0x06 */
};
/* data chunk header */
#define PNM_DATA_HEADER_SIZE 18
const unsigned char pnm_data_header[]={
'D','A','T','A',
0,0,0,0, /* data chunk size */
0,0, /* object version */
0,0,0,0, /* num packets */
0,0,0,0}; /* next data header */
/* pnm request chunk ids */
#define PNA_CLIENT_CAPS 0x03
#define PNA_CLIENT_CHALLANGE 0x04
#define PNA_BANDWIDTH 0x05
#define PNA_GUID 0x13
#define PNA_TIMESTAMP 0x17
#define PNA_TWENTYFOUR 0x18
#define PNA_CLIENT_STRING 0x63
#define PNA_PATH_REQUEST 0x52
const unsigned char pnm_challenge[] = "0990f6b4508b51e801bd6da011ad7b56";
const unsigned char pnm_timestamp[] = "[15/06/1999:22:22:49 00:00]";
const unsigned char pnm_guid[] = "3eac2411-83d5-11d2-f3ea-d7c3a51aa8b0";
const unsigned char pnm_response[] = "97715a899cbe41cee00dd434851535bf";
const unsigned char client_string[] = "WinNT_9.0_6.0.6.45_plus32_MP60_en-US_686l";
#define PNM_HEADER_SIZE 11
const unsigned char pnm_header[] = {
'P','N','A',
0x00, 0x0a,
0x00, 0x14,
0x00, 0x02,
0x00, 0x01 };
#define PNM_CLIENT_CAPS_SIZE 126
const unsigned char pnm_client_caps[] = {
0x07, 0x8a, 'p','n','r','v',
0, 0x90, 'p','n','r','v',
0, 0x64, 'd','n','e','t',
0, 0x46, 'p','n','r','v',
0, 0x32, 'd','n','e','t',
0, 0x2b, 'p','n','r','v',
0, 0x28, 'd','n','e','t',
0, 0x24, 'p','n','r','v',
0, 0x19, 'd','n','e','t',
0, 0x18, 'p','n','r','v',
0, 0x14, 's','i','p','r',
0, 0x14, 'd','n','e','t',
0, 0x24, '2','8','_','8',
0, 0x12, 'p','n','r','v',
0, 0x0f, 'd','n','e','t',
0, 0x0a, 's','i','p','r',
0, 0x0a, 'd','n','e','t',
0, 0x08, 's','i','p','r',
0, 0x06, 's','i','p','r',
0, 0x12, 'l','p','c','J',
0, 0x07, '0','5','_','6' };
const uint32_t pnm_default_bandwidth=10485800;
const uint32_t pnm_available_bandwidths[]={14400,19200,28800,33600,34430,57600,
115200,262200,393216,524300,1544000,10485800};
#define PNM_TWENTYFOUR_SIZE 16
unsigned char pnm_twentyfour[]={
0xd5, 0x42, 0xa3, 0x1b, 0xef, 0x1f, 0x70, 0x24,
0x85, 0x29, 0xb3, 0x8d, 0xba, 0x11, 0xf3, 0xd6 };
/* now other data follows. marked with 0x0000 at the beginning */
int after_chunks_length=6;
unsigned char after_chunks[]={
0x00, 0x00, /* mark */
0x50, 0x84, /* seems to be fixated */
0x1f, 0x3a /* varies on each request (checksum ?)*/
};
static void hexdump (char *buf, int length);
static int rm_write(int s, const char *buf, int len) {
int total, timeout;
total = 0; timeout = 30;
while (total < len){
int n;
n = send (s, &buf[total], len - total, 0);
if (n > 0)
total += n;
else if (n < 0) {
#ifndef HAVE_WINSOCK2
if ((timeout>0) && ((errno == EAGAIN) || (errno == EINPROGRESS))) {
#else
if ((timeout>0) && ((errno == EAGAIN) || (WSAGetLastError() == WSAEINPROGRESS))) {
#endif
sleep (1); timeout--;
} else
return -1;
}
}
return total;
}
static ssize_t rm_read(int fd, void *buf, size_t count) {
ssize_t ret, total;
total = 0;
while (total < count) {
fd_set rset;
struct timeval timeout;
FD_ZERO (&rset);
FD_SET (fd, &rset);
timeout.tv_sec = 3;
timeout.tv_usec = 0;
if (select (fd+1, &rset, NULL, NULL, &timeout) <= 0) {
return -1;
}
ret=recv (fd, ((uint8_t*)buf)+total, count-total, 0);
if (ret<=0) {
printf ("input_pnm: read error.\n");
return ret;
} else
total += ret;
}
return total;
}
/*
* debugging utilities
*/
static void hexdump (char *buf, int length) {
int i;
printf ("input_pnm: ascii>");
for (i = 0; i < length; i++) {
unsigned char c = buf[i];
if ((c >= 32) && (c <= 128))
printf ("%c", c);
else
printf (".");
}
printf ("\n");
printf ("input_pnm: hexdump> ");
for (i = 0; i < length; i++) {
unsigned char c = buf[i];
printf ("%02x", c);
if ((i % 16) == 15)
printf ("\npnm: ");
if ((i % 2) == 1)
printf (" ");
}
printf ("\n");
}
/*
* pnm_get_chunk gets a chunk from stream
* and returns number of bytes read
*/
static int pnm_get_chunk(pnm_t *p,
unsigned int max,
unsigned int *chunk_type,
char *data, int *need_response) {
unsigned int chunk_size;
unsigned int n;
char *ptr;
if (max < PREAMBLE_SIZE)
return -1;
/* get first PREAMBLE_SIZE bytes and ignore checksum */
rm_read (p->s, data, CHECKSUM_SIZE);
if (data[0] == 0x72)
rm_read (p->s, data, PREAMBLE_SIZE);
else
rm_read (p->s, data+CHECKSUM_SIZE, PREAMBLE_SIZE-CHECKSUM_SIZE);
max -= PREAMBLE_SIZE;
*chunk_type = BE_32(data);
chunk_size = BE_32(data+4);
switch (*chunk_type) {
case PNA_TAG:
*need_response=0;
ptr=data+PREAMBLE_SIZE;
if (max < 1)
return -1;
rm_read (p->s, ptr++, 1);
max -= 1;
while(1) {
/* expecting following chunk format: 0x4f <chunk size> <data...> */
if (max < 2)
return -1;
rm_read (p->s, ptr, 2);
max -= 2;
if (*ptr == 'X') /* checking for server message */
{
printf("input_pnm: got a message from server:\n");
if (max < 1)
return -1;
rm_read (p->s, ptr+2, 1);
max = -1;
n=BE_16(ptr+1);
if (max < n)
return -1;
rm_read (p->s, ptr+3, n);
max -= n;
ptr[3+n]=0;
printf("%s\n",ptr+3);
return -1;
}
if (*ptr == 'F') /* checking for server error */
{
printf("input_pnm: server error.\n");
return -1;
}
if (*ptr == 'i')
{
ptr+=2;
*need_response=1;
continue;
}
if (*ptr != 0x4f) break;
n=ptr[1];
if (max < n)
return -1;
rm_read (p->s, ptr+2, n);
max -= n;
ptr+=(n+2);
}
/* the checksum of the next chunk is ignored here */
if (max < 1)
return -1;
rm_read (p->s, ptr+2, 1);
ptr+=3;
chunk_size=ptr-data;
break;
case RMF_TAG:
case DATA_TAG:
case PROP_TAG:
case MDPR_TAG:
case CONT_TAG:
if (chunk_size > max || chunk_size < PREAMBLE_SIZE) {
printf("error: max chunk size exeeded (max was 0x%04x)\n", max);
#ifdef LOG
n=rm_read (p->s, &data[PREAMBLE_SIZE], 0x100 - PREAMBLE_SIZE);
hexdump(data,n+PREAMBLE_SIZE);
#endif
return -1;
}
rm_read (p->s, &data[PREAMBLE_SIZE], chunk_size-PREAMBLE_SIZE);
break;
default:
*chunk_type = 0;
chunk_size = PREAMBLE_SIZE;
break;
}
return chunk_size;
}
/*
* writes a chunk to a buffer, returns number of bytes written
*/
static int pnm_write_chunk(uint16_t chunk_id, uint16_t length,
const char *chunk, char *data) {
data[0]=(chunk_id>>8)%0xff;
data[1]=chunk_id%0xff;
data[2]=(length>>8)%0xff;
data[3]=length%0xff;
memcpy(&data[4],chunk,length);
return length+4;
}
/*
* constructs a request and sends it
*/
static void pnm_send_request(pnm_t *p, uint32_t bandwidth) {
uint16_t i16;
int c=PNM_HEADER_SIZE;
char fixme[]={0,1};
memcpy(p->buffer,pnm_header,PNM_HEADER_SIZE);
c+=pnm_write_chunk(PNA_CLIENT_CHALLANGE,strlen(pnm_challenge),
pnm_challenge,&p->buffer[c]);
c+=pnm_write_chunk(PNA_CLIENT_CAPS,PNM_CLIENT_CAPS_SIZE,
pnm_client_caps,&p->buffer[c]);
c+=pnm_write_chunk(0x0a,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x0c,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x0d,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x16,2,fixme,&p->buffer[c]);
c+=pnm_write_chunk(PNA_TIMESTAMP,strlen(pnm_timestamp),
pnm_timestamp,&p->buffer[c]);
c+=pnm_write_chunk(PNA_BANDWIDTH,4,
(const char *)&pnm_default_bandwidth,&p->buffer[c]);
c+=pnm_write_chunk(0x08,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x0e,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x0f,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x11,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x10,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x15,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(0x12,0,NULL,&p->buffer[c]);
c+=pnm_write_chunk(PNA_GUID,strlen(pnm_guid),
pnm_guid,&p->buffer[c]);
c+=pnm_write_chunk(PNA_TWENTYFOUR,PNM_TWENTYFOUR_SIZE,
pnm_twentyfour,&p->buffer[c]);
/* data after chunks */
memcpy(&p->buffer[c],after_chunks,after_chunks_length);
c+=after_chunks_length;
/* client id string */
p->buffer[c]=PNA_CLIENT_STRING;
i16=BE_16D((strlen(client_string)-1)); /* don't know why do we have -1 here */
memcpy(&p->buffer[c+1],&i16,2);
memcpy(&p->buffer[c+3],client_string,strlen(client_string)+1);
c=c+3+strlen(client_string)+1;
/* file path */
p->buffer[c]=0;
p->buffer[c+1]=PNA_PATH_REQUEST;
i16=BE_16D(strlen(p->path));
memcpy(&p->buffer[c+2],&i16,2);
memcpy(&p->buffer[c+4],p->path,strlen(p->path));
c=c+4+strlen(p->path);
/* some trailing bytes */
p->buffer[c]='y';
p->buffer[c+1]='B';
rm_write(p->s,p->buffer,c+2);
}
/*
* pnm_send_response sends a response of a challenge
*/
static void pnm_send_response(pnm_t *p, const char *response) {
int size=strlen(response);
p->buffer[0]=0x23;
p->buffer[1]=0;
p->buffer[2]=(unsigned char) size;
memcpy(&p->buffer[3], response, size);
rm_write (p->s, p->buffer, size+3);
}
/*
* get headers and challenge and fix headers
* write headers to p->header
* write challenge to p->buffer
*
* return 0 on error. != 0 on success
*/
static int pnm_get_headers(pnm_t *p, int *need_response) {
uint32_t chunk_type;
uint8_t *ptr=p->header;
uint8_t *prop_hdr=NULL;
int chunk_size,size=0;
int nr;
/* rmff_header_t *h; */
*need_response=0;
while(1) {
if (HEADER_SIZE-size<=0)
{
printf("input_pnm: header buffer overflow. exiting\n");
return 0;
}
chunk_size=pnm_get_chunk(p,HEADER_SIZE-size,&chunk_type,ptr,&nr);
if (chunk_size < 0) return 0;
if (chunk_type == 0) break;
if (chunk_type == PNA_TAG)
{
memcpy(ptr, rm_header, RM_HEADER_SIZE);
chunk_size=RM_HEADER_SIZE;
*need_response=nr;
}
if (chunk_type == DATA_TAG)
chunk_size=0;
if (chunk_type == RMF_TAG)
chunk_size=0;
if (chunk_type == PROP_TAG)
prop_hdr=ptr;
size+=chunk_size;
ptr+=chunk_size;
}
if (!prop_hdr) {
printf("input_pnm: error while parsing headers.\n");
return 0;
}
/* set data offset */
size--;
prop_hdr[42]=(size>>24)%0xff;
prop_hdr[43]=(size>>16)%0xff;
prop_hdr[44]=(size>>8)%0xff;
prop_hdr[45]=(size)%0xff;
size++;
/* read challenge */
memcpy (p->buffer, ptr, PREAMBLE_SIZE);
rm_read (p->s, &p->buffer[PREAMBLE_SIZE], 64);
/* now write a data header */
memcpy(ptr, pnm_data_header, PNM_DATA_HEADER_SIZE);
size+=PNM_DATA_HEADER_SIZE;
/*
h=rmff_scan_header(p->header);
rmff_fix_header(h);
p->header_len=rmff_get_header_size(h);
rmff_dump_header(h, p->header, HEADER_SIZE);
*/
p->header_len=size;
return 1;
}
/*
* determine correct stream number by looking at indices
*/
static int pnm_calc_stream(pnm_t *p) {
char str0=0,str1=0;
/* looking at the first index to
* find possible stream types
*/
if (p->seq_current[0]==p->seq_num[0]) str0=1;
if (p->seq_current[0]==p->seq_num[2]) str1=1;
switch (str0+str1) {
case 1: /* one is possible, good. */
if (str0)
{
p->seq_num[0]++;
p->seq_num[1]=p->seq_current[1]+1;
return 0;
} else
{
p->seq_num[2]++;
p->seq_num[3]=p->seq_current[1]+1;
return 1;
}
break;
case 0:
case 2: /* both types or none possible, not so good */
/* try to figure out by second index */
if ( (p->seq_current[1] == p->seq_num[1])
&&(p->seq_current[1] != p->seq_num[3]))
{
/* ok, only stream0 matches */
p->seq_num[0]=p->seq_current[0]+1;
p->seq_num[1]++;
return 0;
}
if ( (p->seq_current[1] == p->seq_num[3])
&&(p->seq_current[1] != p->seq_num[1]))
{
/* ok, only stream1 matches */
p->seq_num[2]=p->seq_current[0]+1;
p->seq_num[3]++;
return 1;
}
/* wow, both streams match, or not. */
/* now we try to decide by timestamps */
if (p->ts_current < p->ts_last[1])
return 0;
if (p->ts_current < p->ts_last[0])
return 1;
/* does not help, we guess type 0 */
#ifdef LOG
printf("guessing stream# 0\n");
#endif
p->seq_num[0]=p->seq_current[0]+1;
p->seq_num[1]=p->seq_current[1]+1;
return 0;
break;
}
printf("input_pnm: wow, something very nasty happened in pnm_calc_stream\n");
return 2;
}
/*
* gets a stream chunk and writes it to a recieve buffer
*/
static int pnm_get_stream_chunk(pnm_t *p) {
int n;
char keepalive='!';
unsigned int fof1, fof2, stream;
/* send a keepalive */
/* realplayer seems to do that every 43th package */
if ((p->packet%43) == 42)
{
rm_write(p->s,&keepalive,1);
}
/* data chunks begin with: 'Z' <o> <o> <i1> 'Z' <i2>
* where <o> is the offset to next stream chunk,
* <i1> is a 16 bit index
* <i2> is a 8 bit index which counts from 0x10 to somewhere
*/
n = rm_read (p->s, p->buffer, 8);
if (n<0) return -1;
if (n<8) return 0;
/* skip 8 bytes if 0x62 is read */
if (p->buffer[0] == 0x62)
{
n = rm_read (p->s, p->buffer, 8);
if (n<8) return 0;
#ifdef LOG
printf("input_pnm: had to seek 8 bytes on 0x62\n");
#endif
}
/* a server message */
if (p->buffer[0] == 'X')
{
int size=BE_16(&p->buffer[1]);
rm_read (p->s, &p->buffer[8], size-5);
p->buffer[size+3]=0;
printf("input_pnm: got message from server while reading stream:\n%s\n", &p->buffer[3]);
return -1;
}
if (p->buffer[0] == 'F')
{
printf("input_pnm: server error.\n");
return -1;
}
/* skip bytewise to next chunk.
* seems, that we don't need that, if we send enough
* keepalives
*/
n=0;
while (p->buffer[0] != 0x5a) {
int i;
for (i=1; i<8; i++) {
p->buffer[i-1]=p->buffer[i];
}
rm_read (p->s, &p->buffer[7], 1);
n++;
}
#ifdef LOG
if (n) printf("input_pnm: had to seek %i bytes to next chunk\n", n);
#endif
/* check for 'Z's */
if ((p->buffer[0] != 0x5a)||(p->buffer[7] != 0x5a))
{
printf("input_pnm: bad boundaries\n");
hexdump(p->buffer, 8);
return 0;
}
/* check offsets */
fof1=BE_16(&p->buffer[1]);
fof2=BE_16(&p->buffer[3]);
if (fof1 != fof2)
{
printf("input_pnm: frame offsets are different: 0x%04x 0x%04x\n",fof1,fof2);
return 0;
}
/* get first index */
p->seq_current[0]=BE_16(&p->buffer[5]);
/* now read the rest of stream chunk */
n = rm_read (p->s, &p->recv[5], fof1-5);
if (n<(fof1-5)) return 0;
/* get second index */
p->seq_current[1]=p->recv[5];
/* get timestamp */
p->ts_current=BE_32(&p->recv[6]);
/* get stream number */
stream=pnm_calc_stream(p);
/* saving timestamp */
p->ts_last[stream]=p->ts_current;
/* constructing a data packet header */
p->recv[0]=0; /* object version */
p->recv[1]=0;
fof2=BE_16(&fof2);
memcpy(&p->recv[2], &fof2, 2);
/*p->recv[2]=(fof2>>8)%0xff;*/ /* length */
/*p->recv[3]=(fof2)%0xff;*/
p->recv[4]=0; /* stream number */
p->recv[5]=stream;
p->recv[10]=p->recv[10] & 0xfe; /* streambox seems to do that... */
p->packet++;
p->recv_size=fof1;
return fof1;
}
// pnm_t *pnm_connect(const char *mrl) {
pnm_t *pnm_connect(int fd, char *path) {
pnm_t *p=malloc(sizeof(pnm_t));
int need_response=0;
p->path=strdup(path);
p->s=fd;
pnm_send_request(p,pnm_available_bandwidths[10]);
if (!pnm_get_headers(p, &need_response)) {
printf ("input_pnm: failed to set up stream\n");
free(p->path);
free(p);
return NULL;
}
if (need_response)
pnm_send_response(p, pnm_response);
p->ts_last[0]=0;
p->ts_last[1]=0;
/* copy header to recv */
memcpy(p->recv, p->header, p->header_len);
p->recv_size = p->header_len;
p->recv_read = 0;
return p;
}
int pnm_read (pnm_t *this, char *data, int len) {
int to_copy=len;
char *dest=data;
char *source=this->recv + this->recv_read;
int fill=this->recv_size - this->recv_read;
int retval;
if (len < 0) return 0;
while (to_copy > fill) {
memcpy(dest, source, fill);
to_copy -= fill;
dest += fill;
this->recv_read=0;
if ((retval = pnm_get_stream_chunk (this)) <= 0) {
#ifdef LOG
printf ("input_pnm: %d of %d bytes provided\n", len-to_copy, len);
#endif
if (retval < 0)
return retval;
else
return len-to_copy;
}
source = this->recv;
fill = this->recv_size - this->recv_read;
}
memcpy(dest, source, to_copy);
this->recv_read += to_copy;
#ifdef LOG
printf ("input_pnm: %d bytes provided\n", len);
#endif
return len;
}
int pnm_peek_header (pnm_t *this, char *data) {
memcpy (data, this->header, this->header_len);
return this->header_len;
}
void pnm_close(pnm_t *p) {
if (p->s >= 0) closesocket(p->s);
free(p->path);
free(p);
}