htnews.c

www工具包

/*			NEWS ACCESS				HTNews.c
**			===========
**
** History:
**	26 Sep 90	Written TBL
**	29 Nov 91	Downgraded to C, for portable implementation.
**	16 Feb 94  AL	Added Lou Montulli's Lynx & LIST NEWSGROUPS diffs.
**	 2 May 94  AL	Added HTUnEscape() to HTLoadNews(), and
**			fixed a possible security hole when the URL contains
**			a newline, that could cause multiple commands to be
**			sent to an NNTP server.
**	 8 Jul 94  FM	Insulate free() from _free structure element.
**	30 Aug 95  FTLO Added POST functionality and updated state machine
**	30 Aug 95  HFN	Cleaned up a whole lot and made a state machine
*/

/* Library Include files */
#include "wwwsys.h"
#include "WWWUtil.h"
#include "WWWCore.h"
#include "WWWStream.h"
#include "WWWTrans.h"
#include "HTReqMan.h"				/* @@@ */
#include "HTNewsRq.h"
#include "HTNewsLs.h"
#include "HTNews.h"					       /* Implements */

/* Macros and other defines */
#ifndef NEWS_LIST_FILE
#define NEWS_LIST_FILE		".www_news"	   /* Name of news list file */
#endif

#define MAX_NEWS_ARTICLES	0 	/* No default max number of articles */

#define PUTBLOCK(b, l)	(*me->target->isa->put_block)	     (me->target, b, l)
#define ABORT_TARGET    (*me->target->isa->abort)            (me->target, e)

/* Local context structure used in the HTNet object */
typedef enum _HTNewsState {
    NEWS_ERROR		= -3,
    NEWS_SUCCESS	= -2,
    NEWS_NO_DATA	= -1,
    NEWS_BEGIN		= 0,
    NEWS_SEEK_CACHE,
    NEWS_NEED_CONNECTION,
    NEWS_NEED_GREETING,
    NEWS_NEED_SWITCH,
    NEWS_NEED_ARTICLE,
#if HT_LISTGROUP
    NEWS_NEED_LGRP,
#endif
    NEWS_NEED_LIST,
    NEWS_NEED_GROUP,
    NEWS_NEED_XOVER,
    NEWS_NEED_HEAD,
    NEWS_NEED_POST,
    NEWS_NEED_BODY
} HTNewsState;

typedef struct _news_info {
    HTChunk *		cmd;
    int			repcode;
    char *		reply;
    HTNewsState         state;                    /* State of the connection */
    HTFormat		format;
    char *		name;		     /* Name of article or newsgroup */
    BOOL		sent;			    /* Read or write command */
    int                 first;            /* First article in the group list */
    int                 last;              /* Last article in the group list */
    int			total;		     /* Estimated number of articles */
    int                 current;                 /* To count # of HEADS sent */
    HTNet *		net;
} news_info;

/* This version of a stream is used for NEWS LIST conversion to HTML */
struct _HTStream {
    const HTStreamClass *	isa;
    HTStream *			target;
    HTRequest *			request;
    news_info *			news;
    HTEOLState			EOLstate;
    BOOL			semi_trans;
    BOOL			junk;
    char 			buffer[MAX_NEWS_LINE+1];
    int				buflen;
    HTHost *			host;
};

struct _HTInputStream {
    const HTInputStreamClass *	isa;
};

PRIVATE int MaxArt = MAX_NEWS_ARTICLES;

/* ------------------------------------------------------------------------- */
/*			       NEWS INPUT STREAM			     */
/* ------------------------------------------------------------------------- */

/*	ScanResponse
**	------------
**	Analyzes the response from the NNTP server.
**	We only expect one line response codes.
**	Returns HT_LOADED if OK, HT_ERROR if error
*/
PRIVATE int ScanResponse (HTStream * me)
{
    news_info *news = me->news;
    *(me->buffer+me->buflen) = '\0';
    if (isdigit((int) *(me->buffer))) sscanf(me->buffer, "%d", &news->repcode);
    me->buflen = 0;
    news->reply = me->buffer+4;
    HTTRACE(PROT_TRACE, "News Rx..... `%s\'\n" _ news->reply);

    /* If 2xx code and we expect data then go into semi-transparent mode */
    if (me->news->format && news->repcode/100 == 2) {
	HTRequest *req = me->request;
	me->target = HTStreamStack(me->news->format, req->output_format,
				   req->output_stream, req, NO);
	me->semi_trans = YES;
	if (!me->target) return HT_ERROR;
    } else if (news->repcode/100 == 4) {
	HTRequest_addError(me->request, ERR_FATAL, NO, HTERR_NOT_FOUND,
			   news->reply, strlen(news->reply), "ScanResponse");
    }
    return HT_LOADED;
}

/*
**	Searches for NNTP header line until buffer fills up or a CRLF or LF
**	is found
*/
PRIVATE int HTNewsStatus_put_block (HTStream * me, const char * b, int l)
{
    int status;
    HTHost_setConsumed(me->host, l);
    while (!me->semi_trans && l-- > 0) {
	if (me->EOLstate == EOL_FCR) {
	    if (*b == LF) {
		if (me->junk) me->junk = NO;
		me->EOLstate = EOL_BEGIN;
		if ((status = ScanResponse(me)) != HT_LOADED) return status;
	    }
	} else if (*b == CR) {
	    me->EOLstate = EOL_FCR;
	} else if (*b == LF) {
	    if (me->junk) me->junk = NO;
	    me->EOLstate = EOL_BEGIN;
	    if ((status = ScanResponse(me)) != HT_LOADED) return status;
	} else {
	    *(me->buffer+me->buflen++) = *b;
	    if (me->buflen >= MAX_NEWS_LINE) {
		HTTRACE(PROT_TRACE, "News Status. Line too long - chopped\n");
		me->junk = YES;
		if ((status = ScanResponse(me)) != HT_LOADED) return status;
	    }
	}
	b++;
    }	

    /*
    ** Now see if we have parts of the body to put down the stream pipe.
    ** At this point we are looking for CRLF.CRLF. We are guaranteed a stream
    */
    if (l > 0) {
	int rest = l;
	const char *ptr = b;
	while (rest-- > 0) {
	    if (*ptr == CR) {
		me->EOLstate = me->EOLstate==EOL_DOT ? EOL_SCR : EOL_FCR;
	    } else if (*ptr == '.') {
		me->EOLstate = me->EOLstate==EOL_FLF ? EOL_DOT : EOL_BEGIN;
	    } else if (*ptr == LF) {
		me->EOLstate = me->EOLstate>EOL_DOT ? EOL_SLF : EOL_FLF;
	    } else
		me->EOLstate = EOL_BEGIN;
	    ptr++;
	}
	if (me->EOLstate == EOL_SLF) {
	    int status = PUTBLOCK(b, l-5);
	    return status != HT_OK ? status : HT_LOADED;
	} else {
	    int status = PUTBLOCK(b, l);
	    return status;
	}
    }
    return HT_LOADED;
}

PRIVATE int HTNewsStatus_put_character (HTStream * me, char ch)
{
    return HTNewsStatus_put_block(me, &ch, 1);
}

PRIVATE int HTNewsStatus_put_string (HTStream * me, const char * str)
{
    return HTNewsStatus_put_block(me, str, (int) strlen(str));
}

PRIVATE int HTNewsStatus_flush (HTStream * me)
{
    return me->target ? (*me->target->isa->flush)(me->target) : HT_OK;
}

PRIVATE int HTNewsStatus_free (HTStream * me)
{
    int status = HT_OK;
    if (me->target) {
	if ((status = (*me->target->isa->_free)(me->target)) == HT_WOULD_BLOCK)
	    return HT_WOULD_BLOCK;
    }
    HT_FREE(me);
    return status;
}

PRIVATE int HTNewsStatus_abort (HTStream * me, HTList * e)
{
    if (me->target)
        ABORT_TARGET;
    HT_FREE(me);
    HTTRACE(PROT_TRACE, "NewsStatus.. ABORTING...\n");
    return HT_ERROR;
}

PRIVATE const HTStreamClass HTNewsStatusClass =
{		
    "NewsStatus",
    HTNewsStatus_flush,
    HTNewsStatus_free,
    HTNewsStatus_abort,
    HTNewsStatus_put_character,
    HTNewsStatus_put_string,
    HTNewsStatus_put_block
};

PRIVATE HTStream * HTNewsStatus_new (HTRequest * request, news_info * news,
				     HTHost * host)
{
    HTStream *me;
    if ((me = (HTStream  *) HT_CALLOC(1, sizeof(HTStream))) == NULL)
        HT_OUTOFMEM("HTNewsStatus_new");
    me->isa = &HTNewsStatusClass;
    me->request = request;
    me->news = news;
    me->EOLstate = EOL_BEGIN;
    me->host = host;
    return me;
}

/* ------------------------------------------------------------------------- */
/*				PROTOCOL FUNCTIONS			     */
/* ------------------------------------------------------------------------- */

/*
**	Set the max number of articles at the same time.
**	Default is MAX_NEWS_ARTICLES
*/
PUBLIC BOOL HTNews_setMaxArticles (int new_max)
{ 
    if (new_max >= 0) {
	MaxArt = new_max;
	return YES;
    }
    return NO;
}

/*
**	Get current max number of articles at the same time.
*/
PUBLIC int HTNews_maxArticles (void)
{ 
    return MaxArt;
}

/*	HTNewsCleanup
**	-------------
**      This function closes the connection and frees memory.
**      Returns YES on OK, else NO
*/
PRIVATE int HTNewsCleanup (HTRequest * req, int status)
{
    HTNet * net = HTRequest_net(req);
    news_info *news = (news_info *) HTNet_context(net);
    HTStream * input = HTRequest_inputStream(req);

    /* Free stream with data TO network */
    if (!HTRequest_isDestination(req))
	HTRequest_removeDestination(req);
    else if (input) {
	if (status == HT_INTERRUPTED)
	    (*input->isa->abort)(input, NULL);
	else
	    (*input->isa->_free)(input);
	HTRequest_setInputStream(req, NULL);
    }

    /* Remove the request object and our own context structure for nntp */
    HTNet_delete(net, status);
    if (news) {
	HT_FREE(news->name);
	HTChunk_delete(news->cmd);
	HT_FREE(news);
    }
    return YES;
}

PRIVATE int SendCommand (HTRequest *request, news_info *news,
			 char *token, char *pars)
{
    HTStream * input = HTRequest_inputStream(request);
    int len = strlen(token) + (pars ? strlen(pars)+1:0) + 2;
    HTChunk_clear(news->cmd);
    HTChunk_ensure(news->cmd, len);
    if (pars && *pars)
	sprintf(HTChunk_data(news->cmd), "%s %s%c%c", token, pars, CR, LF);
    else
	sprintf(HTChunk_data(news->cmd), "%s%c%c", token, CR, LF);
    HTTRACE(PROT_TRACE, "News Tx..... %s" _ HTChunk_data(news->cmd));
    return (*input->isa->put_block)(input, HTChunk_data(news->cmd), len);
}

/*		Load data object from NNTP Server		     HTLoadNews
**		=================================
**
**	Given a hypertext addres, this routine loads a document
**
** On Entry,
**	request		The request structure
**
**	returns		HT_ERROR	Error has occured or interrupted
**			HT_WOULD_BLOCK  if operation would have blocked
**			HT_LOADED	if 200 OK
**			HT_NO_DATA	if No Response
**			HT_RETRY	if Service Unavail.
*/
PRIVATE int NewsEvent (SOCKET soc, void * pVoid, HTEventType type);

PUBLIC int HTLoadNews (SOCKET soc, HTRequest * request)
{
    news_info *news;
    HTParentAnchor *anchor = HTRequest_anchor(request);
    HTNet * net = HTRequest_net(request);
    char * url = HTAnchor_physical(anchor);

    HTTRACE(PROT_TRACE, "NNTP........ Looking for `%s\'\n" _ url);
    if ((news = (news_info *) HT_CALLOC(1, sizeof(news_info))) == NULL)
	HT_OUTOFMEM("HTLoadNews");
    news->cmd = HTChunk_new(128);
    news->state = NEWS_BEGIN;
    news->net = net;
    HTNet_setContext(net, news);
    HTNet_setEventCallback(net, NewsEvent);
    HTNet_setEventParam(net, news);  /* callbacks get http* */

    return NewsEvent(soc, news, HTEvent_BEGIN);		/* get it started - ops is ignored */
}

PRIVATE int NewsEvent (SOCKET soc, void * pVoid, HTEventType type)
{
    news_info *news = (news_info *)pVoid;
    int status = HT_ERROR;
    HTNet * net = news->net;
    HTRequest * request = HTNet_request(net);
    HTParentAnchor * anchor = HTRequest_anchor(request);
    char * url = HTAnchor_physical(anchor);
    HTHost * host = HTNet_host(net);
    
    /*
    ** Initiate a new nntp structure and bind to request structure
    ** This is actually state NNTP_BEGIN, but it can't be in the state
    ** machine as we need the structure first.
    */
    if (type == HTEvent_CLOSE) {			      /* Interrupted */
	HTRequest_addError(request, ERR_FATAL, NO, HTERR_INTERRUPTED,
			   NULL, 0, "HTLoadHTTP");
	HTNewsCleanup(request, HT_INTERRUPTED);
	return HT_OK;
    } else
	news = (news_info *) HTNet_context(net);		/* Get existing copy */

    /* Now jump into the machine. We know the state from the previous run */
    while (1) {
        switch (news->state) {
          case NEWS_BEGIN:
	    news->state = (!strchr(url, '@') && strchr(url, '*')) ?
		NEWS_SEEK_CACHE : NEWS_NEED_CONNECTION;
	    break;