/***************************************************************************** * _ _ ____ _ * 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: http_chunks.c,v 1.1.1.1 2001/04/24 18:49:09 wsanchez Exp $ *****************************************************************************/ #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->dataleft=0; /* no data left yet! */ chunk->state = CHUNK_HEX; /* we get hex first! */ } /* * chunk_read() returns a OK for normal operations, or a positive return code * for errors. STOP means this sequence of chunks is complete. 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 CHUNKE_TOO_LONG_HEX; /* longer hex than we support */ } } else { if(0 == ch->hexindex) { /* This is illegal data, we received junk where we expected a hexadecimal digit. */ return CHUNKE_ILLEGAL_HEX; } /* 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: /* In this state, we're waiting for CRLF to arrive. We support this to allow so called chunk-extensions to show up here before the CRLF comes. */ 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 CHUNKE_STOP; } } 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, we now expect a trailing CRLF */ ch->state = CHUNK_POSTCR; break; case CHUNK_POSTCR: if(*datap == '\r') { ch->state = CHUNK_POSTLF; datap++; length--; } else return CHUNKE_BAD_CHUNK; break; case CHUNK_POSTLF: if(*datap == '\n') { /* * The last one before we go back to hex state and start all * over. */ Curl_httpchunk_init(conn); datap++; length--; } else return CHUNKE_BAD_CHUNK; break; case CHUNK_STOP: /* If we arrive here, there is data left in the end of the buffer even if there's no more chunks to read */ ch->dataleft = length; return CHUNKE_STOP; /* return stop */ default: return CHUNKE_STATE_ERROR; } } return CHUNKE_OK; }