fix crash in mount/export

need to check that status is OK before we start dereferencing the 'export' pointers or else we will segv.
this could happen if trying to pull the list of exports from a host that does not have mountd running, or if we can not connect at all to the host.

diff --git a/examples/nfsclient-sync.c b/examples/nfsclient-sync.c
index 521bf4e1fa5a5d2c3dfdb6e6f3787bf51383b48e..a5af3ce73d19c40db030337eb33a8c05ad94b998 100644 (file)
--- a/examples/nfsclient-sync.c
+++ b/examples/nfsclient-sync.c
@@ -64,15 +64,19 @@ int main(int argc _U_, char *argv[] _U_)
        struct statvfs svfs;
        exports export, tmp;
 
-       printf("exports on server %s\n", SERVER);
        export = mount_getexports(SERVER);
-       tmp = export;
-       while (tmp != NULL) {
-             printf("Export: %s\n", tmp->ex_dir);
-             tmp = tmp->ex_next;
-       }
-       mount_free_export_list(export);
-
+       if (export != NULL) {
+               printf("exports on server %s\n", SERVER);
+               tmp = export;
+               while (tmp != NULL) {
+                     printf("Export: %s\n", tmp->ex_dir);
+                     tmp = tmp->ex_next;
+               }
+
+               mount_free_export_list(export);
+       } else {
+               printf("no exports on server %s\n", SERVER);
+       }       
 
        nfs = nfs_init_context();
        if (nfs == NULL) {

diff --git a/lib/libnfs-sync.c b/lib/libnfs-sync.c
index 29c805c6f4bb135896025add4ca04cf045f4a3ea..4c8ba76a5139eb2e66351498fdc992a55cda8990 100644 (file)
--- a/lib/libnfs-sync.c
+++ b/lib/libnfs-sync.c
@@ -1069,7 +1069,7 @@ int nfs_link(struct nfs_context *nfs, const char *oldpath, const char *newpath)
        return cb_data.status;
 }
 
-void mount_getexports_cb(struct rpc_context *mount_context _U_, int status, void *data, void *private_data)
+void mount_getexports_cb(struct rpc_context *mount_context, int status, void *data, void *private_data)
 {
        struct sync_cb_data *cb_data = private_data;
        exports export = *(exports *)data;
@@ -1078,6 +1078,11 @@ void mount_getexports_cb(struct rpc_context *mount_context _U_, int status, void
        cb_data->status = status;
        cb_data->return_data = NULL;
 
+       if (status != 0) {
+               rpc_set_error(mount_context, "mount/export call failed with \"%s\"", (char *)data);
+               return;
+       }
+
        while (export != NULL) {
                exports new_export;