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| -rw-r--r-- | lib/http_chunks.c | 188 | ||||
| -rw-r--r-- | lib/http_chunks.h | 73 |
2 files changed, 261 insertions, 0 deletions
diff --git a/lib/http_chunks.c b/lib/http_chunks.c new file mode 100644 index 000000000..d22de18d1 --- /dev/null +++ b/lib/http_chunks.c @@ -0,0 +1,188 @@ +/***************************************************************************** + * _ _ ____ _ + * 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; +} diff --git a/lib/http_chunks.h b/lib/http_chunks.h new file mode 100644 index 000000000..5869b9173 --- /dev/null +++ b/lib/http_chunks.h @@ -0,0 +1,73 @@ +#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 |