bogoutil and realpath

[Matthias Andree]

Matthias Andree <matthias.andree at gmx.de> writes:

>> By the way, have you read the manpage of realpath?  It says "do not
>> use" :0
>
> The GNU libc manual pages in their usual vituperating politcal agenda. I
> don't care, realpath() isn't going away anywhen soon, it's in POSIX 2004
> and is not marked "legacy".

Well, it seems GNU has a reason to bitch - their HURD has no PATH_MAX
since that value is dynamic.

So we'll stat and compare st_dev and st_ino - these are unique on a
machine and specific for a directory entry.

How about this patch?
  (I'm not committing this now to avoid conflicting changes.)

BTW, this has an implicit TOCTOU race as it checks earlier than it's
used but if someone feels like hacking symlinks for BOGOHOME underneath
a running bogofilter, their business if they suffer holes in their feet.

Really bedtime now.

Index: src/datastore_db.c
===================================================================
RCS file: /cvsroot/bogofilter/bogofilter/src/datastore_db.c,v
retrieving revision 1.202
diff -u -p -r1.202 datastore_db.c
--- a/src/datastore_db.c	11 Apr 2005 19:06:33 -0000	1.202
+++ b/src/datastore_db.c	21 Apr 2005 22:42:17 -0000
@@ -276,18 +276,6 @@ static void handle_free(/*@only@*/ dbh_t
     return;
 }
 
-static bool checkpath(const char *path, char *norm)
-{
-    if (realpath(path, norm) != NULL)
-	return true;
-    else {
-	print_error(__FILE__, __LINE__,
-		    "error: cannot normalize path \"%s\": %s",
-		    path, strerror(errno));
-	return false;
-    }
-}
-
 /** Initialize data base, configure some lock table sizes
  * (which can be overridden in the DB_CONFIG file)
  * and lock the file to tell other parts we're initialized and
@@ -295,16 +283,23 @@ static bool checkpath(const char *path, 
  */
 void *dbe_init(bfpath *bfp)
 {
-    char norm_dir[PATH_MAX+1]; /* check normalized directory names */
-    char norm_home[PATH_MAX+1];/* see man realpath(3) for details */
-
+    struct stat std, sth;
     dbe_t *env;
 
-    if ( !checkpath(bfp->dirname, norm_dir) ||
-	 !checkpath(bogohome, norm_home))
+    if (stat(bfp->dirname, &std)) {
+	fprintf(stderr, "ERROR: cannot stat \"%s\": %s, aborting.\n",
+		bfp->dirname, strerror(errno));
+	exit(EX_ERROR);
+    }
+
+    if (stat(bogohome, &sth)) {
+	fprintf(stderr, "ERROR: cannot stat \"%s\": %s, aborting.\n",
+		bfp->dirname, strerror(errno));
 	exit(EX_ERROR);
+    }
 
-    if (strcmp(norm_dir, norm_home) != 0)
+    if (std.st_dev != sth.st_dev
+	     || sth.st_ino != sth.st_ino)
     {
 	fprintf(stderr,
 		"ERROR: only one database _environment_ (directory) can be used at a time.\n"
@@ -312,8 +307,7 @@ void *dbe_init(bfpath *bfp)
 	fprintf(stderr,
 		"If you need multiple wordlists in different directories,\n"
 		"you cannot use the transactional interface, but you must configure\n"
-		"the non-transactional interface, i. e. ./configure --disable-transactions\n"
-		"then type make clean, after that rebuild and install as usual.\n"
+		"the non-transactional interface.\n"
 		"Note that the data base will no longer be crash-proof in that case.\n"
 		"Please accept our apologies for the inconvenience.\n");
 	fprintf(stderr,
@@ -322,7 +316,7 @@ void *dbe_init(bfpath *bfp)
     }
 
     dsm_init(bfp);
-    
+
     env = dsm->dsm_env_init(bfp);
 
     return env;

-- 
Matthias Andree