htmime.c

www工具包. 这是W3C官方支持的www支撑库. 其中提供通用目的的客户端的WebAPI: complete HTTP/1.1 (with caching, pipelining, PUT, POS

/*								       HTMIME.c
**	MIME MESSAGE PARSE
**
**	(c) COPYRIGHT MIT 1995.
**	Please first read the full copyright statement in the file COPYRIGH.
**	@(#) $Id: HTMIME.c,v 2.101 2000/12/18 17:00:56 kahan Exp $
**
**	This is RFC 1341-specific code.
**	The input stream pushed into this parser is assumed to be
**	stripped on CRs, ie lines end with LF, not CR LF.
**	(It is easy to change this except for the body part where
**	conversion can be slow.)
**
** History:
**	   Feb 92	Written Tim Berners-Lee, CERN
**	 8 Jul 94  FM	Insulate free() from _free structure element.
**	14 Mar 95  HFN	Now using response for storing data. No more `\n',
**			static buffers etc.
*/

/* Library include files */
#include "wwwsys.h"
#include "WWWUtil.h"
#include "WWWCore.h"
#include "HTReqMan.h"
#include "HTNetMan.h"
#include "HTHeader.h"
#include "HTWWWStr.h"

#ifndef NO_CACHE
#include "HTTee.h"
#include "HTConLen.h"
#include "HTMerge.h"
#include "WWWCache.h"
#endif

#include "HTMIME.h"					 /* Implemented here */

typedef enum _HTMIMEMode {
    HT_MIME_HEADER	= 0x1,
    HT_MIME_FOOTER	= 0x2,
    HT_MIME_PARTIAL	= 0x4,
    HT_MIME_CONT	= 0x8,
    HT_MIME_UPGRADE	= 0x10
} HTMIMEMode;

struct _HTStream {
    const HTStreamClass *	isa;
    HTRequest *			request;
    HTResponse *		response;
    HTNet *			net;
    HTStream *			target;
    HTConverter *		save_stream;
    HTFormat			target_format;
    HTChunk *			token;
    HTChunk *			value;
    int				hash;
    HTEOLState			EOLstate;
    HTMIMEMode			mode;
    BOOL			transparent;
    BOOL			haveToken;
    BOOL			hasBody;
};

PRIVATE HTConverter * LocalSaveStream = NULL; /* Where to save unknown stuff */

/* ------------------------------------------------------------------------- */

PRIVATE int pumpData (HTStream * me)
{
    HTRequest * request = me->request;
    HTResponse * response = me->response;
    HTFormat format = HTResponse_format(response);
    HTList * te = HTResponse_transfer(response);
    HTList * ce = HTResponse_encoding(response);
    long length = HTResponse_length(response);
    HTStream * BlackHole = HTBlackHole();
    BOOL savestream = NO;
    me->transparent = YES;		  /* Pump rest of data right through */

    /*
    **  Cache the metainformation in the anchor object by copying
    **  it from the response object. This we do regardless if
    **  we have a persistent cache or not as the memory cache will
    **  use it as well. If we are updating a cache entry using
    **  byte ranges then we already have the metainformation and
    **  hence we can ignore the new one as it'd better be the same.
    */
    if (!(me->mode & HT_MIME_PARTIAL) &&
	HTResponse_isCachable(me->response) != HT_NO_CACHE)
	HTAnchor_update(HTRequest_anchor(request), me->response);

    /*
    **  If we asked only to read the header or footer or we used a HEAD
    **  method then we stop here as we don't expect any body part.
    */
    if (me->mode & (HT_MIME_HEADER | HT_MIME_FOOTER) ||
	HTRequest_method(request) == METHOD_HEAD) {
        HTAlertCallback * cbf = HTAlert_find(HT_PROG_DONE);
        if (cbf) (*cbf)(request, HT_PROG_DONE, HT_MSG_NULL, NULL, NULL, NULL);
        return HT_LOADED;
    }

    /*
    **  If we are paring a 1xx response then return HT_CONTINUE
    */
    if (me->mode & HT_MIME_CONT)
	return HT_CONTINUE;

    /*
    **  If we get a 101 Protocol Switch then we are done here
    **  but not done with the response (which we don't know
    **  how to go about parsing
    */
    if (me->mode & HT_MIME_UPGRADE) {
	me->hasBody = YES;
	return HT_OK;
    }

    /*
    **  If there is no content-length, no transfer encoding and no
    **  content type then we assume that there is no body part in
    **  the message and we can return HT_LOADED
    */
    {
	HTHost * host = HTNet_host(me->net);
	if (length<0 && te==NULL &&
	    HTHost_isPersistent(host) && !HTHost_closeNotification(host)) {
	    if (format != WWW_UNKNOWN) {
		HTTRACE(STREAM_TRACE, "MIME Parser. BAD - there seems to be a body but no length. This must be an HTTP/1.0 server pretending that it is HTTP/1.1\n");
		HTHost_setCloseNotification(host, YES);
	    } else {
                HTAlertCallback * cbf = HTAlert_find(HT_PROG_DONE);
                if (cbf) (*cbf)(request, HT_PROG_DONE, HT_MSG_NULL, NULL, NULL, NULL);
		HTTRACE(STREAM_TRACE, "MIME Parser. No body in this message\n");
		return HT_LOADED;
	    }
	}
    }

    /*
    **  Deal with the body
    */
    me->hasBody = YES;

    /*
    **  Handle any Content Type
    */
    if (!(me->mode & HT_MIME_PARTIAL) &&
	(format != WWW_UNKNOWN || length > 0 || te)) {
	HTStream * target;
	HTTRACE(STREAM_TRACE, "Building.... C-T stack from %s to %s\n" _ 
				  HTAtom_name(format) _ 
				  HTAtom_name(me->target_format));
	if ((target = HTStreamStack(format, me->target_format,
				    me->target, request, YES))==BlackHole) {
	    if (!savestream) {
                if (me->target) (*me->target->isa->abort)(me->target, NULL);
                me->target = me->save_stream(request, NULL,
					     format, me->target_format, me->target);
		savestream = YES;
	    }
	} else
	    me->target = target;
    }

    /*
    **  Handle any Content Encodings
    */
    HTTRACE(STREAM_TRACE, "Building.... Content-Decoding stack\n");
    if (ce) {
	HTStream * target = HTContentDecodingStack(ce, me->target, request, NULL);
	if (target == BlackHole) {
	    if (!savestream) {
		if (me->target) (*me->target->isa->abort)(me->target, NULL);
                me->target = me->save_stream(request, NULL,
					     format, me->target_format, me->target);
		savestream = YES;
	    }
	} else
	    me->target = target;
    }

    /*
    **  Can we cache the data object? If so then create a T stream and hook it 
    **  into the stream pipe. We do it before the transfer decoding so that we
    **  don't have to deal with that when we retrieve the object from cache.
    **  If we are appending to a cache entry then use a different stream than
    **  if creating a new entry.
    */
#ifndef NO_CACHE
    if (HTCacheMode_enabled()) {
	if (me->mode & HT_MIME_PARTIAL) {
	    HTStream * append = HTStreamStack(WWW_CACHE_APPEND,
					      me->target_format,
					      me->target, request, NO);
	    if (append) me->target = HTTee(me->target, append, NULL);
#if 0
	    /* @@ JK: change */
	    if (append) me->target = append;
#endif
	} else if (HTResponse_isCachable(me->response) == HT_CACHE_ALL) {
	    HTStream * cache = HTStreamStack(WWW_CACHE, me->target_format,
					     me->target, request, NO);
	    if (cache) me->target = HTTee(me->target, cache, NULL);
	}
    }
#endif
    
    /*
    **  Handle any Transfer Encodings
    */
    HTTRACE(STREAM_TRACE, "Building.... Transfer-Decoding stack\n");
    if (te) {
	HTStream * target = HTTransferDecodingStack(te, me->target, request, NULL);
	if (target == BlackHole) {
	    if (!savestream) {
		if (me->target) (*me->target->isa->abort)(me->target, NULL);
                me->target = me->save_stream(request, NULL,
					     format, me->target_format, me->target);
		savestream = YES;
	    }
	} else
	    me->target = target;
    }


    /*
    ** If we for some reason couldn't find a target stream
    */
    if (!me->target) me->target = HTBlackHole();
    return HT_OK;
}

/* _dispatchParsers
 * call request's MIME header parser. Use global parser if no 
 * appropriate one is found for request.
*/
PRIVATE int _dispatchParsers (HTRequest * req, char * token, char * value)
{
    int status;
    BOOL found = NO;
    BOOL local = NO;
    HTMIMEParseSet * parseSet;

    /* In case we get an empty header consisting of a CRLF, we fall thru */
    HTTRACE(STREAM_TRACE, "MIME header. %s: %s\n" _ 
			      token ? token : "<null>" _ 
			      value ? value : "<null>");
    if (!token) return HT_OK;			    /* Ignore noop token */

    /*
    ** Search the local set of MIME parsers
    */
    if ((parseSet = HTRequest_MIMEParseSet(req, &local)) != NULL) {
        status = HTMIMEParseSet_dispatch(parseSet, req, 
					 token, value, &found);
	if (found) return status;
    }

    /*
    ** Search the global set of MIME parsers
    */
    if (local==NO && (parseSet = HTHeader_MIMEParseSet()) != NULL) {
	status = HTMIMEParseSet_dispatch(parseSet, req, 
					 token, value, &found);
	if (found) return status;
    }

    return HT_OK;
}

/* _stream2dispatchParsers - extracts the arguments from a
 * MIME stream before calling the generic _dispatchParser
 * function.
 */
PRIVATE int _stream2dispatchParsers (HTStream * me)
{
    char * token = HTChunk_data(me->token);
    char * value = HTChunk_data(me->value);

    /* In case we get an empty header consisting of a CRLF, we fall thru */
    HTTRACE(STREAM_TRACE, "MIME header. %s: %s\n" _ 
			      token ? token : "<null>" _ 
			      value ? value : "<null>");
    if (!token) return HT_OK;			    /* Ignore noop token */

    /*
    ** Remember the original header
    */
    HTResponse_addHeader(me->response, token, value);

    /* call the parsers to set the headers */
    return (_dispatchParsers (me->request, token, value));
}

/*
**	Header is terminated by CRCR, LFLF, CRLFLF, CRLFCRLF
**	Folding is either of CF LWS, LF LWS, CRLF LWS
*/
PRIVATE int HTMIME_put_block (HTStream * me, const char * b, int l)
{
    const char * start = b;
    const char * end = start;
    const char * value = HTChunk_size(me->value) > 0 ? b : NULL;
    int length = l;
    int status;

    while (!me->transparent) {
	if (me->EOLstate == EOL_FCR) {
	    if (*b == CR)				    /* End of header */
	        me->EOLstate = EOL_END;
	    else if (*b == LF)			   	     /* CRLF */
		me->EOLstate = EOL_FLF;
	    else if (isspace((int) *b))			   /* Folding: CR SP */
	        me->EOLstate = EOL_FOLD;
	    else						 /* New line */
	        me->EOLstate = EOL_LINE;
	} else if (me->EOLstate == EOL_FLF) {
	    if (*b == CR)				/* LF CR or CR LF CR */
		me->EOLstate = EOL_SCR;
	    else if (*b == LF)				    /* End of header */
	        me->EOLstate = EOL_END;
	    else if (isspace((int) *b))	       /* Folding: LF SP or CR LF SP */
		me->EOLstate = EOL_FOLD;
	    else						/* New line */
		me->EOLstate = EOL_LINE;
	} else if (me->EOLstate == EOL_SCR) {
	    if (*b==CR || *b==LF)			    /* End of header */
	        me->EOLstate = EOL_END;
	    else if (isspace((int) *b))	 /* Folding: LF CR SP or CR LF CR SP */
		me->EOLstate = EOL_FOLD;
	    else						/* New line */
		me->EOLstate = EOL_LINE;
	} else if (*b == CR)
	    me->EOLstate = EOL_FCR;
	else if (*b == LF)
	    me->EOLstate = EOL_FLF;			       /* Line found */
	else {
	    if (!me->haveToken) {
	        if (*b == ':' || isspace((int) *b)) {
		    HTChunk_putb(me->token, start, end-start);
		    HTChunk_putc(me->token, '\0');
		    me->haveToken = YES;
		} else {
		    unsigned char ch = *(unsigned char *) b;
		    ch = TOLOWER(ch);
		    me->hash = (me->hash * 3 + ch) % MIME_HASH_SIZE;
		}
	    } else if (value == NULL && *b != ':' && !isspace((int) *b))
	        value = b;
	    end++;
	}
	switch (me->EOLstate) {
	    case EOL_LINE:
	    case EOL_END:
	    {
		int ret = HT_ERROR;
		HTChunk_putb(me->value, value, end-value);
		HTChunk_putc(me->value, '\0');
		ret =  _stream2dispatchParsers(me);
		HTNet_addBytesRead(me->net, b-start);
		start=b, end=b;
		if (me->EOLstate == EOL_END) {		/* EOL_END */
		    if (ret == HT_OK) {
			b++, l--;
			ret = pumpData(me);
			HTNet_addBytesRead(me->net, 1);
			if (me->mode & (HT_MIME_FOOTER | HT_MIME_CONT)) {
			    HTHost_setConsumed(HTNet_host(me->net), length - l);
			    return ret;
                        } else {
                            HTNet_setHeaderBytesRead(me->net, HTNet_bytesRead(me->net));
                        }
		    }
	        } else {				/* EOL_LINE */
		    HTChunk_truncate(me->token,0);
		    HTChunk_truncate(me->value,0);
		    me->haveToken = NO;
		    me->hash = 0;
		    value = NULL;
		}
		me->EOLstate = EOL_BEGIN;
		if (ret != HT_OK && ret != HT_LOADED) return ret;
		break;
	    }
	    case EOL_FOLD:
		me->EOLstate = EOL_BEGIN;
	        if (!me->haveToken) {
		    HTChunk_putb(me->token, start, end-start);
		    HTChunk_putc(me->token, '\0');
		    me->haveToken = YES;
	        } else if (value) {
		    HTChunk_putb(me->value, value, end-value);
		    HTChunk_putc(me->value, ' ');
		}
		start=b, end=b;
		break;
	    default: 
	        b++, l--;
	        if (!l) {
		    BOOL stop = NO;
		    if (!me->haveToken) {
			/* If empty header then prepare to stop */
			if (end-start)
			    HTChunk_putb(me->token, start, end-start);
			else
			    stop = YES;
		    } else if (value)
		        HTChunk_putb(me->value, value, end-value);
		    HTHost_setConsumed(HTNet_host(me->net), length - l);
		    return stop ? pumpData(me) : HT_OK;
		}
	}
    }

    if (length != l) HTHost_setConsumed(HTNet_host(me->net), length - l);

    /*