#include <u.h>#include <libc.h>#include <ctype.h>#include <bio.h>#include <regexp.h>#include <fcall.h>#include "httpd.h"#include "httpsrv.h" static	Hio		*hout;static	Hio		houtb;static	HConnect	*connect;static	int		vermaj, gidwidth, uidwidth, lenwidth, devwidth;static	Biobuf		*aio, *dio; static voiddoctype(void){	hprint(hout, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\"\n");	hprint(hout, "    \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n");} voiderror(char *title, char *fmt, ...){	va_list arg;	char buf[1024], *out; 	va_start(arg, fmt);	out = vseprint(buf, buf+sizeof(buf), fmt, arg);	va_end(arg);	*out = 0; 	hprint(hout, "%s 404 %s\r\n", hversion, title);	hprint(hout, "Date: %D\r\n", time(nil));	hprint(hout, "Server: Plan9\r\n");	hprint(hout, "Content-type: text/html\r\n");	hprint(hout, "\r\n");	doctype();	hprint(hout, "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n");	hprint(hout, "<head><title>%s</title></head>\n", title);	hprint(hout, "<body>\n");	hprint(hout, "<h1>%s</h1>\n", title);	hprint(hout, "%s\n", buf);	hprint(hout, "</body>\n");	hprint(hout, "</html>\n");	hflush(hout);	writelog(connect, "Reply: 404\nReason: %s\n", title);	exits(nil);} /* * Are we actually allowed to look in here? * * Rules: *	1) If neither allowed nor denied files exist, access is granted. *	2) If allowed exists and denied does not, dir *must* be in allowed *	   for access to be granted, otherwise, access is denied. *	3) If denied exists and allowed does not, dir *must not* be in *	   denied for access to be granted, otherwise, access is enied. *	4) If both exist, okay if either (a) file is not in denied, or *	   (b) in denied and in allowed.  Otherwise, access is denied. */static Reprog *getre(Biobuf *buf){	Reprog	*re;	char	*p, *t;	char	*bbuf;	int	n; 	if (buf == nil)		return(nil);	for ( ; ; free(p)) {		p = Brdstr(buf, '\n', 0);		if (p == nil)			return(nil);		t = strchr(p, '#');		if (t != nil)			*t = '\0';		t = p + strlen(p);		while (--t > p && isspace(*t))			*t = '\0';		n = strlen(p);		if (n == 0)			continue; 		/* root the regular expresssion */		bbuf = malloc(n+2);		if(bbuf == nil)			sysfatal("out of memory");		bbuf[0] = '^';		strcpy(bbuf+1, p);		re = regcomp(bbuf);		free(bbuf); 		if (re == nil)			continue;		free(p);		return(re);	}} static intallowed(char *dir){	Reprog	*re;	int	okay;	Resub	match; 	if (strcmp(dir, "..") == 0 || strncmp(dir, "../", 3) == 0)		return(0);	if (aio == nil)		return(0); 	if (aio != nil)		Bseek(aio, 0, 0);	if (dio != nil)		Bseek(dio, 0, 0); 	/* if no deny list, assume everything is denied */	okay = (dio != nil); 	/* go through denials till we find a match */	while (okay && (re = getre(dio)) != nil) {		memset(&match, 0, sizeof(match));		okay = (regexec(re, dir, &match, 1) != 1);		free(re);	} 	/* go through accepts till we have a match */	if (aio == nil)		return(okay);	while (!okay && (re = getre(aio)) != nil) {		memset(&match, 0, sizeof(match));		okay = (regexec(re, dir, &match, 1) == 1);		free(re);	}	return(okay);} /* * Comparison routine for sorting the directory. */static intcompar(Dir *a, Dir *b){	return(strcmp(a->name, b->name));} /* * These is for formating; how wide are variable-length * fields? */static voidmaxwidths(Dir *dp, long n){	long	i;	char	scratch[64]; 	for (i = 0; i < n; i++) {		if (snprint(scratch, sizeof scratch, "%ud", dp[i].dev) > devwidth)			devwidth = strlen(scratch);		if (strlen(dp[i].uid) > uidwidth)			uidwidth = strlen(dp[i].uid);		if (strlen(dp[i].gid) > gidwidth)			gidwidth = strlen(dp[i].gid);		if (snprint(scratch, sizeof scratch, "%lld", dp[i].length) > lenwidth)			lenwidth = strlen(scratch);	}} /* * Do an actual directory listing. * asciitime is lifted directly out of ls. */char *asciitime(long l){	ulong clk;	static char buf[32];	char *t; 	clk = time(nil);	t = ctime(l);	/* 6 months in the past or a day in the future */	if(l<clk-180L*24*60*60 || clk+24L*60*60<l){		memmove(buf, t+4, 7);		/* month and day */		memmove(buf+7, t+23, 5);		/* year */	}else		memmove(buf, t+4, 12);		/* skip day of week */	buf[12] = 0;	return buf;} static voiddols(char *dir){	Dir	*d;	char	*f, *p,*nm;	long	i, n;	int	fd; 	/* expand "" to "."; ``dir+1'' access below depends on this */	cleanname(dir);	if (!allowed(dir)) {		error("Permission denied", "<p>Cannot list directory %s: Access prohibited</p>", dir);		return;	}	fd = open(dir, OREAD);	if (fd < 0) {		error("Cannot read directory", "<p>Cannot read directory %s: %r</p>", dir);		return;	}	if (vermaj) {		hokheaders(connect);		hprint(hout, "Content-type: text/html\r\n");		hprint(hout, "\r\n");	}	doctype();	hprint(hout, "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n");	hprint(hout, "<head><title>Index of %s</title></head>\n", dir);	hprint(hout, "<body>\n");	hprint(hout, "<h1>Index of ");	nm = dir;	while((p = strchr(nm, '/')) != nil){		*p = '\0';		f = (*dir == '\0') ? "/" : dir;		if (!(*dir == '\0' && *(dir+1) == '\0') && allowed(f))			hprint(hout, "<a href=\"/magic/webls?dir=%H\">%s/</a>", f, nm);		else			hprint(hout, "%s/", nm);		*p = '/';		nm = p+1;	}	hprint(hout, "%s</h1>\n", nm);	n = dirreadall(fd, &d);	close(fd);	maxwidths(d, n);	qsort(d, n, sizeof(Dir), (int (*)(void *, void *))compar);	hprint(hout, "<pre>\n");	for (i = 0; i < n; i++) {		f = smprint("%s/%s", dir, d[i].name);		cleanname(f);		if (d[i].mode & DMDIR) {			p = smprint("/magic/webls?dir=%H", f);			free(f);			f = p;		}		hprint(hout, "%M %C %*ud %-*s %-*s %*lld %s <a href=\"%s\">%s</a>\n",		    d[i].mode, d[i].type,		    devwidth, d[i].dev,		    uidwidth, d[i].uid,		    gidwidth, d[i].gid,		    lenwidth, d[i].length,		    asciitime(d[i].mtime), f, d[i].name);		free(f);	}	f = smprint("%s/..", dir);	cleanname(f);	if (strcmp(f, dir) != 0 && allowed(f))		hprint(hout, "\nGo to <a href=\"/magic/webls?dir=%H\">parent</a> directory\n", f);	else		hprint(hout, "\nEnd of directory listing\n");	free(f);	hprint(hout, "</pre>\n</body>\n</html>\n");	hflush(hout);	free(d);} /* * Handle unpacking the request in the URI and * invoking the actual handler. */static voiddosearch(char *search){	if (strncmp(search, "dir=", 4) == 0){		search = hurlunesc(connect, search+4);		dols(search);		return;	} 	/*	 * Otherwise, we've gotten an illegal request.	 * spit out a non-apologetic error.	 */	search = hurlunesc(connect, search);	error("Bad directory listing request",	    "<p>Illegal formatted directory listing request:</p>\n"	    "<p>%H</p>", search);} voidmain(int argc, char **argv){	fmtinstall('H', httpfmt);	fmtinstall('U', hurlfmt);	fmtinstall('M', dirmodefmt); 	aio = Bopen("/sys/lib/webls.allowed", OREAD);	dio = Bopen("/sys/lib/webls.denied", OREAD); 	if(argc == 2){		hinit(&houtb, 1, Hwrite);		hout = &houtb;		dols(argv[1]);		exits(nil);	}	close(2); 	connect = init(argc, argv);	hout = &connect->hout;	vermaj = connect->req.vermaj;	if(hparseheaders(connect, HSTIMEOUT) < 0)		exits("failed"); 	if(strcmp(connect->req.meth, "GET") != 0 && strcmp(connect->req.meth, "HEAD") != 0){		hunallowed(connect, "GET, HEAD");		exits("not allowed");	}	if(connect->head.expectother || connect->head.expectcont){		hfail(connect, HExpectFail, nil);		exits("failed");	} 	bind(webroot, "/", MREPL); 	if(connect->req.search != nil)		dosearch(connect->req.search);	else		error("Bad argument", "<p>Need a search argument</p>");	hflush(hout);	writelog(connect, "200 webls %ld %ld\n", hout->seek, hout->seek);	exits(nil);}