mountd: Add lookup_export_parent()

[nfs-utils.git] / utils / mountd / cache.c

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index f63803bddb31a2e5bab1e974b9e1bc05402f9677..b858e6001ccceb2f9dbf8b4eb1aefb7375802158 100644 (file)
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -830,6 +830,60 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
 #include <dlfcn.h>
 #include <nfs-plugin.h>
 
+/*
+ * Find the export entry for the parent of "pathname".
+ * Caller must not free returned exportent.
+ */
+static struct exportent *lookup_parent_export(char *dom,
+               const char *pathname, struct addrinfo *ai)
+{
+       char *parent, *slash;
+       nfs_export *result;
+
+       parent = strdup(pathname);
+       if (parent == NULL) {
+               xlog(D_GENERAL, "%s: failed to allocate parent path buffer",
+                       __func__);
+               goto out_default;
+       }
+       xlog(D_CALL, "%s: pathname = '%s'", __func__, pathname);
+
+again:
+       /* shorten pathname by one component */
+       slash = strrchr(parent, '/');
+       if (slash == NULL) {
+               xlog(D_GENERAL, "%s: no slash found in pathname",
+                       __func__);
+               goto out_default;
+       }
+       *slash = '\0';
+
+       if (strlen(parent) == 0) {
+               result = lookup_export(dom, "/", ai);
+               if (result == NULL) {
+                       xlog(L_ERROR, "%s: no root export found.", __func__);
+                       goto out_default;
+               }
+               goto out;
+       }
+
+       result = lookup_export(dom, parent, ai);
+       if (result == NULL) {
+               xlog(D_GENERAL, "%s: lookup_export(%s) found nothing",
+                       __func__, parent);
+               goto again;
+       }
+
+out:
+       xlog(D_CALL, "%s: found export for %s", __func__, parent);
+       free(parent);
+       return &result->m_export;
+
+out_default:
+       free(parent);
+       return mkexportent("*", "/", "insecure");
+}
+
 /*
  * Walk through a set of FS locations and build an e_fslocdata string.
  * Returns true if all went to plan; otherwise, false.
@@ -918,7 +972,8 @@ out_false:
  * Returned exportent points to static memory.
  */
 static struct exportent *locations_to_export(struct jp_ops *ops,
-               nfs_fsloc_set_t locations, const char *junction)
+               nfs_fsloc_set_t locations, const char *junction,
+               struct exportent *UNUSED(parent))
 {
        static char fslocdata[BUFSIZ];
        struct exportent *exp;
@@ -955,10 +1010,10 @@ static struct exportent *locations_to_export(struct jp_ops *ops,
  *
  * Returned exportent points to static memory.
  */
-static struct exportent *invoke_junction_ops(void *handle,
-               const char *junction)
+static struct exportent *invoke_junction_ops(void *handle, char *dom,
+               const char *junction, struct addrinfo *ai)
 {
-       struct exportent *exp = NULL;
+       struct exportent *parent, *exp = NULL;
        nfs_fsloc_set_t locations;
        enum jp_status status;
        struct jp_ops *ops;
@@ -998,7 +1053,11 @@ static struct exportent *invoke_junction_ops(void *handle,
                goto out;
        }
 
-       exp = locations_to_export(ops, locations, junction);
+       parent = lookup_parent_export(dom, junction, ai);
+       if (parent == NULL)
+               goto out;
+
+       exp = locations_to_export(ops, locations, junction, parent);
 
        ops->jp_put_locations(locations);
 
@@ -1014,7 +1073,8 @@ out:
  *
  * Returned exportent points to static memory.
  */
-static struct exportent *lookup_junction(const char *pathname)
+static struct exportent *lookup_junction(char *dom, const char *pathname,
+               struct addrinfo *ai)
 {
        struct exportent *exp;
        void *handle;
@@ -1026,7 +1086,7 @@ static struct exportent *lookup_junction(const char *pathname)
        }
        (void)dlerror();        /* Clear any error */
 
-       exp = invoke_junction_ops(handle, pathname);
+       exp = invoke_junction_ops(handle, dom, pathname, ai);
 
        /* We could leave it loaded to make junction resolution
         * faster next time.  However, if we want to replace the
@@ -1035,7 +1095,8 @@ static struct exportent *lookup_junction(const char *pathname)
        return exp;
 }
 #else  /* !HAVE_NFS_PLUGIN_H */
-static inline struct exportent *lookup_junction(const char *UNUSED(pathname))
+static inline struct exportent *lookup_junction(char *UNUSED(dom),
+               const char *UNUSED(pathname), struct addrinfo *UNUSED(ai))
 {
        return NULL;
 }
@@ -1089,7 +1150,7 @@ static void nfsd_export(FILE *f)
                        dump_to_cache(f, dom, path, NULL);
                }
        } else {
-               dump_to_cache(f, dom, path, lookup_junction(path));
+               dump_to_cache(f, dom, path, lookup_junction(dom, path, ai));
        }
  out:
        xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);