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chunked transfer encoding support

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This commit is contained in:
Daniel Stenberg
2001-03-07 23:28:22 +00:00
parent bcf448ee32
commit 55b8ceac18
2 changed files with 261 additions and 0 deletions
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188
lib/http_chunks.c Normal file
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/*****************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2001, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* In order to be useful for every potential user, curl and libcurl are
* dual-licensed under the MPL and the MIT/X-derivate licenses.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the MPL or the MIT/X-derivate
* licenses. You may pick one of these licenses.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* $Id$
*****************************************************************************/
#include "setup.h"
/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include "urldata.h" /* it includes http_chunks.h */
#include "sendf.h" /* for the client write stuff */
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
/* The last #include file should be: */
#ifdef MALLOCDEBUG
#include "memdebug.h"
#endif
/*
* Chunk format (simplified):
*
* <HEX SIZE>[ chunk extension ] CRLF
* <DATA>
*
* Highlights from RFC2616 section 3.6 say:
The chunked encoding modifies the body of a message in order to
transfer it as a series of chunks, each with its own size indicator,
followed by an OPTIONAL trailer containing entity-header fields. This
allows dynamically produced content to be transferred along with the
information necessary for the recipient to verify that it has
received the full message.
Chunked-Body = *chunk
last-chunk
trailer
CRLF
chunk = chunk-size [ chunk-extension ] CRLF
chunk-data CRLF
chunk-size = 1*HEX
last-chunk = 1*("0") [ chunk-extension ] CRLF
chunk-extension= *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
chunk-ext-name = token
chunk-ext-val = token | quoted-string
chunk-data = chunk-size(OCTET)
trailer = *(entity-header CRLF)
The chunk-size field is a string of hex digits indicating the size of
the chunk. The chunked encoding is ended by any chunk whose size is
zero, followed by the trailer, which is terminated by an empty line.
*/
void Curl_httpchunk_init(struct connectdata *conn)
{
struct Curl_chunker *chunk = &conn->proto.http->chunk;
chunk->hexindex=0; /* start at 0 */
chunk->state = CHUNK_HEX; /* we get hex first! */
}
/*
* chunk_read() returns a 0 for normal operations, or a positive return code
* for errors. A negative number means this sequence of chunks is complete,
* and that many ~bytes were NOT used at the end of the buffer passed in.
* The 'wrote' argument is set to tell the caller how many bytes we actually
* passed to the client (for byte-counting and whatever).
*
* The states and the state-machine is further explained in the header file.
*/
CHUNKcode Curl_httpchunk_read(struct connectdata *conn,
char *datap,
ssize_t length,
ssize_t *wrote)
{
CURLcode result;
struct Curl_chunker *ch = &conn->proto.http->chunk;
int piece;
*wrote = 0; /* nothing yet */
while(length) {
switch(ch->state) {
case CHUNK_HEX:
if(isxdigit((int)*datap)) {
if(ch->hexindex < MAXNUM_SIZE) {
ch->hexbuffer[ch->hexindex] = *datap;
datap++;
length--;
ch->hexindex++;
}
else {
return 1; /* longer hex than we support */
}
}
else {
/* length and datap are unmodified */
ch->hexbuffer[ch->hexindex]=0;
ch->datasize=strtoul(ch->hexbuffer, NULL, 16);
ch->state = CHUNK_POSTHEX;
}
break;
case CHUNK_POSTHEX:
/* just a lame state waiting for CRLF to arrive */
if(*datap == '\r')
ch->state = CHUNK_CR;
length--;
datap++;
break;
case CHUNK_CR:
/* waiting for the LF */
if(*datap == '\n') {
/* we're now expecting data to come, unless size was zero! */
if(0 == ch->datasize) {
ch->state = CHUNK_STOP; /* stop reading! */
if(1 == length) {
/* This was the final byte, return right now */
return ~0;
}
}
else
ch->state = CHUNK_DATA;
}
else
/* previously we got a fake CR, go back to CR waiting! */
ch->state = CHUNK_CR;
datap++;
length--;
break;
case CHUNK_DATA:
/* we get pure and fine data
We expect another 'datasize' of data. We have 'length' right now,
it can be more or less than 'datasize'. Get the smallest piece.
*/
piece = (ch->datasize >= length)?length:ch->datasize;
/* Write the data portion available */
result = Curl_client_write(conn->data, CLIENTWRITE_BODY, datap, piece);
if(result)
return CHUNKE_WRITE_ERROR;
*wrote += piece;
ch->datasize -= piece; /* decrease amount left to expect */
datap += piece; /* move read pointer forward */
length -= piece; /* decrease space left in this round */
if(0 == ch->datasize)
/* end of data this round, go back to get a new size */
Curl_httpchunk_init(conn);
break;
case CHUNK_STOP:
return ~length; /* return the data size left */
default:
return CHUNKE_STATE_ERROR;
}
}
return CHUNKE_OK;
}

73
lib/http_chunks.h Normal file
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#ifndef __HTTP_CHUNKS_H
#define __HTTP_CHUNKS_H
/*****************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2001, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* In order to be useful for every potential user, curl and libcurl are
* dual-licensed under the MPL and the MIT/X-derivate licenses.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the MPL or the MIT/X-derivate
* licenses. You may pick one of these licenses.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* $Id$
*****************************************************************************/
/*
* The longest possible hexadecimal number we support in a chunked transfer.
* Weird enoug, RFC2616 doesn't set a maximum size! Since we use strtoul()
* to convert it, we "only" support 2^32 bytes chunk data.
*/
#define MAXNUM_SIZE 16
typedef enum {
CHUNK_LOST, /* never use */
/* In this we await and buffer all hexadecimal digits until we get one
that isn't a hexadecimal digit. When done, we go POSTHEX */
CHUNK_HEX,
/* We have received the hexadecimal digit and we eat all characters until
we get a CRLF pair. When we see a CR we go to the CR state. */
CHUNK_POSTHEX,
/* A single CR has been found and we should get a LF right away in this
state or we go back to POSTHEX. When LF is received, we go to DATA.
If the size given was zero, we set state to STOP and return. */
CHUNK_CR,
/* We eat the amount of data specified. When done, we move back to the
HEX state. */
CHUNK_DATA,
/* This is only used to really mark that we're out of the game */
CHUNK_STOP,
CHUNK_LAST /* never use */
} ChunkyState;
typedef enum {
CHUNKE_OK,
CHUNKE_TOO_LONG_HEX,
CHUNKE_WRITE_ERROR,
CHUNKE_STATE_ERROR,
CHUNKE_LAST
} CHUNKcode;
struct Curl_chunker {
char hexbuffer[ MAXNUM_SIZE + 1];
int hexindex;
ChunkyState state;
unsigned long datasize;
};
#endif