The is_subdirectory() function checks if a given 'child' is a subdirectory
of the given 'parent'.
However it always fails if 'parent' == "/" (because 'child' doesn't begin
with 'parent' followed by "/").
So change is_subdirectory() to special-case "/".
subexport() also tests if one directory is a subdirectory of the
other, and contains the same bug. So change it to use is_subdirectory().
Finally, move is_subdirectory() and related path_matches() and
export_matches() earlier in the file to avoid a forward-reference.
This patch fixes a bug wherein if you export "/" with 'crossmnt', the
crossmnt flag is ineffective and you can only access the root
filesystem, not any descendants.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 3853bb6..45012be 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -343,6 +343,30 @@ static char *next_mnt(void **v, char *p)
return me->mnt_dir;
}
+static int is_subdirectory(char *child, char *parent)
+{
+ size_t l = strlen(parent);
+
+ if (strcmp(parent, "/") == 0)
+ return 1;
+
+ return strcmp(child, parent) == 0
+ || (strncmp(child, parent, l) == 0 && child[l] == '/');
+}
+
+static int path_matches(nfs_export *exp, char *path)
+{
+ if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
+ return is_subdirectory(path, exp->m_export.e_path);
+ return strcmp(path, exp->m_export.e_path) == 0;
+}
+
+static int
+export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
+{
+ return path_matches(exp, path) && client_matches(exp, dom, ai);
+}
+
/* True iff e1 is a child of e2 and e2 has crossmnt set: */
static bool subexport(struct exportent *e1, struct exportent *e2)
{
@@ -350,8 +374,7 @@ static bool subexport(struct exportent *e1, struct exportent *e2)
size_t l2 = strlen(p2);
return e2->e_flags & NFSEXP_CROSSMOUNT
- && strncmp(p1, p2, l2) == 0
- && p1[l2] == '/';
+ && is_subdirectory(p1, p2);
}
struct parsed_fsid {
@@ -752,27 +775,6 @@ static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *ex
return qword_eol(f);
}
-static int is_subdirectory(char *child, char *parent)
-{
- size_t l = strlen(parent);
-
- return strcmp(child, parent) == 0
- || (strncmp(child, parent, l) == 0 && child[l] == '/');
-}
-
-static int path_matches(nfs_export *exp, char *path)
-{
- if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
- return is_subdirectory(path, exp->m_export.e_path);
- return strcmp(path, exp->m_export.e_path) == 0;
-}
-
-static int
-export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
-{
- return path_matches(exp, path) && client_matches(exp, dom, ai);
-}
-
static nfs_export *
lookup_export(char *dom, char *path, struct addrinfo *ai)
{
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