nfs: add structures and functions for parsing netgroups

Netgroups are often used by enterprises to group a set of systems. The
NFS /etc/exports file support the @netgroup notation, and Gluster/NFS
will get extended to support this notation as well. For this, it is
needed that Gluster/NFS learns to parse the netgroup format.

A change to glusterfsd (Change-Id I24c40d5) will add test cases where
the parsing is used for regression testing.

BUG: 1143880
Change-Id: Ie04800d4dc26f99df922c9fcc00845f53291cf4f
Original-author: Shreyas Siravara <shreyas.siravara@gmail.com>
CC: Richard Wareing <rwareing@fb.com>
CC: Jiffin Tony Thottan <jthottan@redhat.com>
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/9360
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

xlators/nfs/server/src/Makefile.am

@@ -4,13 +4,13 @@ nfsrpclibdir = $(top_srcdir)/rpc/rpc-lib/src
 server_la_LDFLAGS = -module -avoid-version
 server_la_SOURCES = nfs.c nfs-common.c nfs-fops.c nfs-inodes.c \
 	nfs-generics.c mount3.c nfs3-fh.c nfs3.c nfs3-helpers.c nlm4.c \
-	nlmcbk_svc.c mount3udp_svc.c acl3.c
+	nlmcbk_svc.c mount3udp_svc.c acl3.c netgroups.c
 server_la_LIBADD = $(top_builddir)/libglusterfs/src/libglusterfs.la \
                    $(top_builddir)/api/src/libgfapi.la
 
 noinst_HEADERS = nfs.h nfs-common.h nfs-fops.h nfs-inodes.h nfs-generics.h \
 	mount3.h nfs3-fh.h nfs3.h nfs3-helpers.h nfs-mem-types.h nlm4.h \
-	acl3.h
+	acl3.h netgroups.h
 
 AM_CPPFLAGS = $(GF_CPPFLAGS) \
 	-DLIBDIR=\"$(libdir)/glusterfs/$(PACKAGE_VERSION)/auth\" \

xlators/nfs/server/src/netgroups.h

@@ -0,0 +1,54 @@
+/*
+   Copyright 2014-present Facebook. All Rights Reserved
+
+   This file is part of GlusterFS.
+
+   Author :
+   Shreyas Siravara <shreyas.siravara@gmail.com>
+
+   This file is licensed to you under your choice of the GNU Lesser
+   General Public License, version 3 or any later version (LGPLv3 or
+   later), or the GNU General Public License, version 2 (GPLv2), in all
+   cases as published by the Free Software Foundation.
+*/
+
+#ifndef _NETGROUPS_H
+#define _NETGROUPS_H
+
+#include "nfs-mem-types.h"
+#include "dict.h"
+#include "nfs.h"
+
+#define GF_NG GF_NFS"-netgroup"
+
+#define NG_FILE_PARSE_REGEX "([a-zA-Z0-9.(,)]+)"
+#define NG_HOST_PARSE_REGEX "([a-zA-Z0-9.]+)"
+
+struct netgroup_host {
+        char *hostname;         /* Hostname of entry */
+        char *user;             /* User field in the entry */
+        char *domain;           /* Domain field in the entry */
+};
+
+struct netgroup_entry {
+        char    *netgroup_name;         /* Name of the netgroup */
+        dict_t  *netgroup_ngs;          /* Dict of netgroups in this netgroup */
+        dict_t  *netgroup_hosts;        /* Dict of hosts in this netgroup. */
+};
+
+struct netgroups_file {
+        char    *filename;         /* Filename on disk */
+        dict_t  *ng_file_dict;   /* Dict of netgroup entries */
+};
+
+struct netgroups_file *
+ng_file_parse (const char *filepath);
+
+struct netgroup_entry *
+ng_file_get_netgroup (const struct netgroups_file *ngfile,
+                      const char *netgroup);
+
+void
+ng_file_deinit (struct netgroups_file *ngfile);
+
+#endif /* _NETGROUPS_H */

xlators/nfs/server/src/nfs-mem-types.h

@@ -46,6 +46,7 @@ enum gf_nfs_mem_types_ {
         gf_nfs_mt_aux_gids,
         gf_nfs_mt_inode_ctx,
         gf_nfs_mt_auth_spec,
+        gf_nfs_mt_netgroups,
         gf_nfs_mt_arr,
         gf_nfs_mt_end
 };