From c70fc7215d521b4729d6ac5d7df2f0d2da8352de Mon Sep 17 00:00:00 2001
From: Thomas Schmitt <scdbackup@gmx.net>
Date: Wed, 27 Sep 2006 14:22:32 +0000
Subject: [PATCH] Curbed endless links to 20 hops

---
 cdrskin/cdrskin_timestamp.h |  2 +-
 libburn/drive.c             | 31 ++++++++++++++++++++++++++-----
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/cdrskin/cdrskin_timestamp.h b/cdrskin/cdrskin_timestamp.h
index 04b58cd..d6d1ed0 100644
--- a/cdrskin/cdrskin_timestamp.h
+++ b/cdrskin/cdrskin_timestamp.h
@@ -1 +1 @@
-#define Cdrskin_timestamP "2006.09.27.134332"
+#define Cdrskin_timestamP "2006.09.27.142312"
diff --git a/libburn/drive.c b/libburn/drive.c
index 299b5b9..8c87e51 100644
--- a/libburn/drive.c
+++ b/libburn/drive.c
@@ -28,6 +28,8 @@ static struct burn_drive drive_array[255];
 static int drivetop = -1;
 
 int burn_drive_is_open(struct burn_drive *d);
+int burn_drive_convert_fs_adr_sub(char *path, char adr[], int *rec_count);
+
 
 /* ts A60904 : ticket 62, contribution by elmom */
 /* splitting former burn_drive_free() (which freed all, into two calls) */
@@ -723,14 +725,23 @@ int burn_drive_is_enumerable_adr(char *adr)
 	return sg_is_enumerable_adr(adr);
 }
 
+#define BURN_DRIVE_MAX_LINK_DEPTH 20
+
 /* ts A60922 ticket 33 */
 /* Try to find an enumerated address with the given stat.st_rdev number */
-int burn_drive_resolve_link(char *path, char adr[])
+int burn_drive_resolve_link(char *path, char adr[], int *recursion_count)
 {
 	int ret;
 	char link_target[4096], msg[4096+100], link_adr[4096], *adrpt;
 
-	burn_drive_adr_debug_msg("burn_drive_resolve_link( %s )",path);
+	burn_drive_adr_debug_msg("burn_drive_resolve_link( %s )", path);
+	if (*recursion_count >= BURN_DRIVE_MAX_LINK_DEPTH) {
+		burn_drive_adr_debug_msg(
+			"burn_drive_resolve_link aborts because link too deep",
+			NULL);
+		return 0;
+	}
+	(*recursion_count)++;
 	ret = readlink(path, link_target, sizeof(link_target));
 	if (ret == -1) {
 		burn_drive_adr_debug_msg("readlink( %s ) returns -1", path);
@@ -751,7 +762,7 @@ int burn_drive_resolve_link(char *path, char adr[])
 		} else
 			adrpt = link_target;
 	}
-	ret = burn_drive_convert_fs_adr(adrpt, adr);
+	ret = burn_drive_convert_fs_adr_sub(adrpt, adr, recursion_count);
 	sprintf(msg,"burn_drive_convert_fs_adr( %s ) returns %d",
 		link_target, ret);
 	burn_drive_adr_debug_msg(msg, NULL);
@@ -891,7 +902,7 @@ int burn_drive_find_scsi_equiv(char *path, char adr[])
 /* ts A60922 ticket 33 */
 /** Try to convert a given existing filesystem address into a persistent drive
     address.  */
-int burn_drive_convert_fs_adr(char *path, char adr[])
+int burn_drive_convert_fs_adr_sub(char *path, char adr[], int *rec_count)
 {
 	int ret;
 	struct stat stbuf;
@@ -911,7 +922,7 @@ int burn_drive_convert_fs_adr(char *path, char adr[])
 		return 0;
 	}
 	if((stbuf.st_mode & S_IFMT) == S_IFLNK) {
-		ret = burn_drive_resolve_link(path, adr);
+		ret = burn_drive_resolve_link(path, adr, rec_count);
 		if(ret > 0)
 			return 1;
 		burn_drive_adr_debug_msg("link fallback via stat( %s )", path);
@@ -933,3 +944,13 @@ int burn_drive_convert_fs_adr(char *path, char adr[])
 	return 0;
 }
 
+/** Try to convert a given existing filesystem address into a persistent drive
+    address.  */
+int burn_drive_convert_fs_adr(char *path, char adr[])
+{
+	int ret, rec_count = 0;
+
+	ret = burn_drive_convert_fs_adr_sub(path, adr, &rec_count);
+	return ret;
+}
+