htfile.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

/*								       HTFile.c
**	FILE ACCESS
**
**	(c) COPYRIGHT MIT 1995.
**	Please first read the full copyright statement in the file COPYRIGH.
**	@(#) $Id: HTFile.c,v 1.158 2000/08/10 16:05:39 kahan Exp $
**
**	This is unix-specific code in general, with some VMS bits.
**	These are routines for file access used by browsers.
**
** History:
**	   Feb 91	Written Tim Berners-Lee CERN/CN
**	   Apr 91	vms-vms access included using DECnet syntax
**	26 Jun 92 (JFG) When running over DECnet, suppressed FTP.
**			Fixed access bug for relative names on VMS.
**	   Sep 93 (MD)  Access to VMS files allows sharing.
**	15 Nov 93 (MD)	Moved HTVMSname to HTVMSUTILS.C
**	22 Feb 94 (MD)  Excluded two routines if we are not READING directories
**	18 May 94 (HF)	Directory stuff removed and stream handling updated,
**			error messages introduced etc.
**		  HFN	Separated transport
**
** Bugs:
**	FTP: Cannot access VMS files from a unix machine.
**      How can we know that the
**	target machine runs VMS?
*/

/* Library Includes */
#include "wwwsys.h"
#include "WWWUtil.h"
#include "WWWCore.h"
#include "WWWDir.h"
#include "WWWTrans.h"
#include "HTReqMan.h"
#include "HTBind.h"
#include "HTMulti.h"
#include "HTFile.h"		/* Implemented here */

/* Final states have negative value */
typedef enum _FileState {
    FS_RETRY		= -4,
    FS_ERROR		= -3,
    FS_NO_DATA		= -2,
    FS_GOT_DATA		= -1,
    FS_BEGIN		= 0,
    FS_PENDING,
    FS_DO_CN,
    FS_NEED_OPEN_FILE,
    FS_NEED_BODY,
    FS_PARSE_DIR,
    FS_TRY_FTP
} FileState;

/* This is the context structure for the this module */
typedef struct _file_info {
    FileState		state;		  /* Current state of the connection */
    char *		local;		/* Local representation of file name */
    struct stat		stat_info;	      /* Contains actual file chosen */
    HTNet *		net;
    HTTimer *		timer;
} file_info;

struct _HTStream {
    const HTStreamClass *	isa;
};

struct _HTInputStream {
    const HTInputStreamClass *	isa;
};

PRIVATE HTDirReadme	dir_readme = HT_DIR_README_TOP;
PRIVATE HTDirAccess	dir_access = HT_DIR_OK;
PRIVATE HTDirShow	dir_show = HT_DS_SIZE+HT_DS_DATE+HT_DS_DES+HT_DS_ICON;
PRIVATE HTDirKey	dir_key = HT_DK_CINS;
PRIVATE BOOL		file_suffix_binding = YES;

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

/*	Directory Access
**	----------------
*/
PUBLIC BOOL HTFile_setDirAccess (HTDirAccess mode)
{
    dir_access = mode;
    return YES;
}

PUBLIC HTDirAccess HTFile_dirAccess (void)
{
    return dir_access;
}

/*	Directory Readme
**	----------------
*/
PUBLIC BOOL HTFile_setDirReadme (HTDirReadme mode)
{
    dir_readme = mode;
    return YES;
}

PUBLIC HTDirReadme HTFile_dirReadme (void)
{
    return dir_readme;
}

/*
**  Should we find the bindings between file suffixes and media types
**  here or not?
*/
PUBLIC BOOL HTFile_doFileSuffixBinding (BOOL mode)
{
    file_suffix_binding = mode;
    return YES;
}

PUBLIC BOOL HTFile_fileSuffixBinding (void)
{
    return file_suffix_binding;
}

/*	HTFile_readDir
**	--------------
**	Reads the directory "path"
**	Returns:
**		HT_ERROR	Error
**		HT_FORBIDDEN	Directory reading not allowed
**		HT_LOADED	Successfully read the directory
*/
PRIVATE int HTFile_readDir (HTRequest * request, file_info *file)
{
#ifdef HAVE_READDIR
    DIR * dp;
    struct stat file_info;
    HTParentAnchor * anchor = HTRequest_anchor(request);
    char *url = HTAnchor_physical(anchor);
    char fullname[HT_MAX_PATH+1];
    char *name;
    HTTRACE(PROT_TRACE, "Reading..... directory\n");
    if (dir_access == HT_DIR_FORBID) {
	HTRequest_addError(request, ERR_FATAL, NO, HTERR_FORBIDDEN,
		   NULL, 0, "HTFile_readDir");
	return HT_FORBIDDEN;
    }
    
    /* Initialize path name for stat() */
    if (*(name = (url+strlen(url)-1)) != '/') {
	char *newurl = NULL;
	StrAllocCopy(newurl, url);
	StrAllocCat(newurl, "/");
	HT_FREE(file->local);
	file->local = HTWWWToLocal(newurl, "", HTRequest_userProfile(request));
	HT_FREE(newurl);
    }
    strcpy(fullname, file->local);
    name = fullname+strlen(fullname);		 /* Point to end of fullname */

    /* Check if access is enabled */
    if (dir_access == HT_DIR_SELECTIVE) {
	strcpy(name, DEFAULT_DIR_FILE);
	if (HT_STAT(fullname, &file_info)) {
	    HTTRACE(PROT_TRACE, "Read dir.... `%s\' not found\n" _ DEFAULT_DIR_FILE);
	    HTRequest_addError(request, ERR_FATAL, NO, HTERR_FORBIDDEN,
		       NULL, 0, "HTFile_readDir");
	    return HT_FORBIDDEN;
	}
    }

    if ((dp = opendir(file->local))) {
	struct dirent * dirbuf;
	HTDir *dir = HTDir_new(request, dir_show, dir_key);
	char datestr[20];
	char sizestr[10];
	HTFileMode mode;
#ifdef HT_REENTRANT
	struct dirent result;				    /* For readdir_r */
#endif

#ifdef HAVE_READDIR_R_2
        while ((dirbuf = (struct dirent *) readdir_r(dp, &result)))
#elif defined(HAVE_READDIR_R_3)
        while (readdir_r(dp, &result, &dirbuf) == 0)
#else
	while ((dirbuf = readdir(dp)))
#endif /* HAVE_READDIR_R_2 */
	{
	    /* Current and parent directories are never shown in list */
#ifdef HAVE_DIRENT_INO
	    if (!dirbuf->d_ino ||
		!strcmp(dirbuf->d_name, ".") || !strcmp(dirbuf->d_name, ".."))
#else
	    if (!strcmp(dirbuf->d_name, ".") || !strcmp(dirbuf->d_name, ".."))
#endif
		continue;

	    /* Make a lstat on the file */
	    strcpy(name, dirbuf->d_name);
	    if (HT_LSTAT(fullname, &file_info)) {
		HTTRACE(PROT_TRACE, "Read dir.... lstat failed: %s\n" _ fullname);
		continue;
	    }

	    /* Convert stat info to fit our setup */
	    if (((mode_t) file_info.st_mode & S_IFMT) == S_IFDIR) {
#ifdef VMS
		char *dot = strstr(name, ".DIR");      /* strip .DIR part... */
		if (dot) *dot = '\0';
#endif /* VMS */
		mode = HT_IS_DIR;
		if (dir_show & HT_DS_SIZE) strcpy(sizestr, "-");
	    } else {
		mode = HT_IS_FILE;
		if (dir_show & HT_DS_SIZE)
		    HTNumToStr(file_info.st_size, sizestr, 10);
	    }
	    if (dir_show & HT_DS_DATE)
		HTDateDirStr(&file_info.st_mtime, datestr, 20);

	    /* Add to the list */
	    if (HTDir_addElement(dir, name, datestr, sizestr, mode) != YES)
		break;
	}
	closedir(dp);
	HTDir_free(dir);
	return HT_LOADED;
    } else {
	HTRequest_addSystemError(request,  ERR_FATAL, errno, NO, "opendir");
	return HT_ERROR;
    }
#else
    return HT_ERROR;	/* needed for WWW_MSWINDOWS */
#endif /* HAVE_READDIR */
}

/*	Determine write access to a file
**	--------------------------------
**	If stat_info is NULL then the function calls stat() on it's own,
**	otherwise it uses the information found in stat_info
** On exit,
**	return value	YES if file can be accessed and can be written to.
**
** Bugs:
**	1.	No code for non-unix systems.
**	2.	Isn't there a quicker way?
*/
PRIVATE BOOL HTEditable (const char * filename, struct stat * stat_info)
{
#ifdef GETGROUPS_T
    int i;
    uid_t myUid;
    int	ngroups;			/* The number of groups  */
    struct stat	fileStatus;
    struct stat *fileptr = stat_info ? stat_info : &fileStatus;
    GETGROUPS_T groups[NGROUPS];
    if (!stat_info) {
	if (HT_STAT(filename, &fileStatus))
	    return NO;				  /* Can't even access file! */
    }
    ngroups = getgroups(NGROUPS, groups);	/* Groups to which I belong  */
    myUid = geteuid();				/* Get my user identifier */

#ifdef HTDEBUG
    if (PROT_TRACE) {
        int i;
	HTTRACE(PROT_TRACE,
		"File mode is 0%o, uid=%d, gid=%d. My uid=%d, %d groups (" _
		(unsigned int) fileptr->st_mode _
		(int) fileptr->st_uid _ (int) fileptr->st_gid _
		(int) myUid _ ngroups);
	for (i=0; i<ngroups; i++) HTTRACE(PROT_TRACE, " %d" _ (int) groups[i]);
	HTTRACE(PROT_TRACE, ")\n");
    }
#endif /* HTDEBUG */
    
    if (fileptr->st_mode & 0002)		/* I can write anyway? */
    	return YES;
	
    if ((fileptr->st_mode & 0200)		/* I can write my own file? */
     && (fileptr->st_uid == myUid))
    	return YES;

    if (fileptr->st_mode & 0020)		/* Group I am in can write? */
    {
   	for (i=0; i<ngroups; i++) {
            if (groups[i] == fileptr->st_gid)
	        return YES;
	}
    }
    HTTRACE(PROT_TRACE, "\tFile is not editable.\n");
    return NO;					/* If no excuse, can't do */
#else
    /*
    ** We don't know and can't find out. Can we be sure that when opening
    ** a file in mode "a" that the file is not modified?
    */
    return NO;
#endif /* GETGROUPS_T */
}

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

    /* Free stream with data TO Local file system */
    if (input) {
        if (status == HT_INTERRUPTED)
            (*input->isa->abort)(input, NULL);
        else
            (*input->isa->_free)(input);
        HTRequest_setInputStream(req, NULL);
    }

    /*
    **  Remove if we have registered a timer function as a callback
    */
    if (file->timer) {
	HTTimer_delete(file->timer);
	file->timer = NULL;
    }

    if (file) {
	HT_FREE(file->local);
	HT_FREE(file);
    }
    HTNet_delete(net, status);
    return YES;
}


/*	Load a document
**	---------------
**
** On entry,