===================================================================
RCS file: /cvs/mandoc/cgi.c,v
retrieving revision 1.73
retrieving revision 1.78
diff -u -p -r1.73 -r1.78
--- mandoc/cgi.c	2014/07/13 15:38:36	1.73
+++ mandoc/cgi.c	2014/07/21 15:45:17	1.78
@@ -1,4 +1,4 @@
-/*	$Id: cgi.c,v 1.73 2014/07/13 15:38:36 schwarze Exp $ */
+/*	$Id: cgi.c,v 1.78 2014/07/21 15:45:17 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014 Ingo Schwarze <schwarze@usta.de>
@@ -79,7 +79,6 @@ static	void		 resp_searchform(const struct req *);
 static	void		 resp_show(const struct req *, const char *);
 
 static	const char	 *scriptname; /* CGI script name */
-static	const char	 *httphost; /* hostname used in the URIs */
 
 static	const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9};
 static	const char *const sec_numbers[] = {
@@ -467,6 +466,32 @@ resp_searchform(const struct req *req)
 	puts("<!-- End search form. //-->");
 }
 
+static int
+validate_manpath(const struct req *req, const char* manpath)
+{
+	size_t	 i;
+
+	if ( ! strcmp(manpath, "mandoc"))
+		return(1);
+
+	for (i = 0; i < req->psz; i++)
+		if ( ! strcmp(manpath, req->p[i]))
+			return(1);
+
+	return(0);
+}
+
+static int
+validate_filename(const char *file)
+{
+
+	if ('.' == file[0] && '/' == file[1])
+		file += 2;
+
+	return ( ! (strstr(file, "../") || strstr(file, "/..") ||
+	    (strncmp(file, "man", 3) && strncmp(file, "cat", 3))));
+}
+
 static void
 pg_index(const struct req *req)
 {
@@ -524,6 +549,15 @@ pg_searchres(const struct req *req, struct manpage *r,
 	int		 prio, priouse;
 	char		 sec;
 
+	for (i = 0; i < sz; i++) {
+		if (validate_filename(r[i].file))
+			continue;
+		fprintf(stderr, "invalid filename %s in %s database\n",
+		    r[i].file, req->q.manpath);
+		pg_error_internal();
+		return;
+	}
+
 	if (1 == sz) {
 		/*
 		 * If we have just one result, then jump there now
@@ -531,7 +565,7 @@ pg_searchres(const struct req *req, struct manpage *r,
 		 */
 		printf("Status: 303 See Other\r\n");
 		printf("Location: http://%s%s/%s/%s?",
-		    httphost, scriptname, req->q.manpath, r[0].file);
+		    HTTP_HOST, scriptname, req->q.manpath, r[0].file);
 		http_printquery(req);
 		printf("\r\n"
 		     "Content-Type: text/html; charset=utf-8\r\n"
@@ -778,7 +812,8 @@ format(const struct req *req, const char *file)
 static void
 resp_show(const struct req *req, const char *file)
 {
-	if ('.' == file[0] || '/' == file[1])
+
+	if ('.' == file[0] && '/' == file[1])
 		file += 2;
 
 	if ('c' == *file)
@@ -799,6 +834,12 @@ pg_show(const struct req *req, const char *path)
 	} 
 	*sub++ = '\0';
 
+	if ( ! validate_manpath(req, path)) {
+		pg_error_badrequest(
+		    "You specified an invalid manpath.");
+		return;
+	}
+
 	/*
 	 * Begin by chdir()ing into the manpath.
 	 * This way we can pick up the database files, which are
@@ -806,8 +847,15 @@ pg_show(const struct req *req, const char *path)
 	 */
 
 	if (-1 == chdir(path)) {
+		fprintf(stderr, "chdir %s: %s\n",
+		    path, strerror(errno));
+		pg_error_internal();
+		return;
+	}
+
+	if ( ! validate_filename(sub)) {
 		pg_error_badrequest(
-		    "You specified an invalid manpath.");
+		    "You specified an invalid manual file.");
 		return;
 	}
 
@@ -835,8 +883,9 @@ pg_search(const struct req *req)
 	 */
 
 	if (-1 == (chdir(req->q.manpath))) {
-		pg_error_badrequest(
-		    "You specified an invalid manpath.");
+		fprintf(stderr, "chdir %s: %s\n",
+		    req->q.manpath, strerror(errno));
+		pg_error_internal();
 		return;
 	}
 
@@ -907,9 +956,6 @@ main(void)
 	if (NULL == (scriptname = getenv("SCRIPT_NAME")))
 		scriptname = "";
 
-	if (NULL == (httphost = getenv("HTTP_HOST")))
-		httphost = "localhost";
-
 	/*
 	 * First we change directory into the MAN_DIR so that
 	 * subsequent scanning for manpath directories is rooted
@@ -931,6 +977,12 @@ main(void)
 	if (NULL != (querystring = getenv("QUERY_STRING")))
 		http_parse(&req, querystring);
 
+	if ( ! validate_manpath(&req, req.q.manpath)) {
+		pg_error_badrequest(
+		    "You specified an invalid manpath.");
+		return(EXIT_FAILURE);
+	}
+
 	/* Dispatch to the three different pages. */
 
 	path = getenv("PATH_INFO");
@@ -970,8 +1022,12 @@ pathgen(struct req *req)
 	char	*dp;
 	size_t	 dpsz;
 
-	if (NULL == (fp = fopen("manpath.conf", "r")))
-		return;
+	if (NULL == (fp = fopen("manpath.conf", "r"))) {
+		fprintf(stderr, "%s/manpath.conf: %s\n",
+			MAN_DIR, strerror(errno));
+		pg_error_internal();
+		exit(EXIT_FAILURE);
+	}
 
 	while (NULL != (dp = fgetln(fp, &dpsz))) {
 		if ('\n' == dp[dpsz - 1])
@@ -979,5 +1035,11 @@ pathgen(struct req *req)
 		req->p = mandoc_realloc(req->p,
 		    (req->psz + 1) * sizeof(char *));
 		req->p[req->psz++] = mandoc_strndup(dp, dpsz);
+	}
+
+	if ( req->p == NULL ) {
+		fprintf(stderr, "%s/manpath.conf is empty\n", MAN_DIR);
+		pg_error_internal();
+		exit(EXIT_FAILURE);
 	}
 }