autofs-5.1.2 - check for conflicting amd section mounts

From: Ian Kent <raven@themaw.net>

Allowing the addition of amd section mounts to the master mounts list

can lead to conflicting mount point paths.

Check for conflicts and skip the amd mount section mounts if a conflict

with the master map mounts is found.

Signed-off-by: Ian Kent <raven@themaw.net>

---

 CHANGELOG        |    1 

 include/master.h |    1 

 lib/master.c     |   59 ++++++++++++++++++++++++++++++++++++++++++++++++++++---

 3 files changed, 58 insertions(+), 3 deletions(-)

--- autofs-5.0.7.orig/CHANGELOG

+++ autofs-5.0.7/CHANGELOG

@@ -228,6 +228,7 @@

 - add function conf_amd_get_map_name().

 - add function conf_amd_get_mount_paths().

 - include amd mount sections mounts in master mounts list.

+- check for conflicting amd section mounts.

 25/07/2012 autofs-5.0.7

 =======================

--- autofs-5.0.7.orig/include/master.h

+++ autofs-5.0.7/include/master.h

@@ -106,6 +106,7 @@ void master_source_lock_cleanup(void *);

 void master_source_current_wait(struct master_mapent *);

 void master_source_current_signal(struct master_mapent *);

 struct master_mapent *master_find_mapent(struct master *, const char *);

+unsigned int master_partial_match_mapent(struct master *, const char *);

 struct autofs_point *__master_find_submount(struct autofs_point *, const char *);

 struct autofs_point *master_find_submount(struct autofs_point *, const char *);

 struct amd_entry *__master_find_amdmount(struct autofs_point *, const char *);

--- autofs-5.0.7.orig/lib/master.c

+++ autofs-5.0.7/lib/master.c

@@ -710,6 +710,53 @@ struct master_mapent *master_find_mapent

 	return NULL;

 }

+unsigned int master_partial_match_mapent(struct master *master, const char *path)

+{

+	struct list_head *head, *p;

+	size_t path_len = strlen(path);

+	int ret = 0;

+

+	head = &master->mounts;

+	list_for_each(p, head) {

+		struct master_mapent *entry;

+		size_t entry_len;

+		size_t cmp_len;

+

+		entry = list_entry(p, struct master_mapent, list);

+

+		entry_len = strlen(entry->path);

+		cmp_len = min(entry_len, path_len);

+

+		if (!strncmp(entry->path, path, cmp_len)) {

+			/* paths are equal, matching master map entry ? */

+			if (entry_len == path_len) {

+				if (entry->maps &&

+				    entry->maps->flags & MAP_FLAG_FORMAT_AMD)

+					ret = 1;

+				else

+					ret = -1;

+				break;

+			}

+

+			/* amd mount conflicts with entry mount */

+			if (entry_len > path_len &&

+			    *(entry->path + path_len) == '/') {

+				ret = -1;

+				break;

+			}

+

+			/* entry mount conflicts with amd mount */

+			if (entry_len < path_len &&

+			    *(path + entry_len) == '/') {

+				ret = -1;

+				break;

+			}

+		}

+	}

+

+	return ret;

+}

+

 struct autofs_point *__master_find_submount(struct autofs_point *ap, const char *path)

 {

 	struct list_head *head, *p;

@@ -936,10 +983,16 @@ static void master_add_amd_mount_section

 		char *type = NULL;

 		char *map = NULL;

-		entry = master_find_mapent(master, path);

-		if (entry) {

+		ret = master_partial_match_mapent(master, path);

+		if (ret) {

+			/* If this amd entry is already present in the

+			 * master map it's not a duplicate, don't issue

+			 * an error message.

+			 */

+			if (ret == 1)

+				goto next;

 			info(m_logopt,

-			     "ignoring duplicate amd section mount %s",

+			     "amd section mount path conflict, %s ignored",

 			     path);

 			goto next;

 		}