[PATCH] NFSD: Add server support for NFSv3 ACLs. (a257cdd0) · Commits · e / devices / android_kernel_fairphone_FP3

fs/Kconfig

+24 −0

Original line number	Diff line number	Diff line
		@@ -1353,6 +1353,7 @@ config NFSD
		select LOCKD
		select SUNRPC
		select EXPORTFS
		select NFS_ACL_SUPPORT if NFSD_V3_ACL \|\| NFSD_V2_ACL
		help
		If you want your Linux box to act as an NFS server, so that other
		computers on your local network which support NFS can access certain
		@@ -1376,6 +1377,10 @@ config NFSD
		To compile the NFS server support as a module, choose M here: the
		module will be called nfsd. If unsure, say N.

		config NFSD_V2_ACL
		bool
		depends on NFSD

		config NFSD_V3
		bool "Provide NFSv3 server support"
		depends on NFSD
		@@ -1383,6 +1388,16 @@ config NFSD_V3
		If you would like to include the NFSv3 server as well as the NFSv2
		server, say Y here. If unsure, say Y.

		config NFSD_V3_ACL
		bool "Provide server support for the NFSv3 ACL protocol extension"
		depends on NFSD_V3
		select NFSD_V2_ACL
		help
		Implement the NFSv3 ACL protocol extension for manipulating POSIX
		Access Control Lists on exported file systems. NFS clients should
		be compiled with the NFSv3 ACL protocol extension; see the
		CONFIG_NFS_V3_ACL option. If unsure, say N.

		config NFSD_V4
		bool "Provide NFSv4 server support (EXPERIMENTAL)"
		depends on NFSD_V3 && EXPERIMENTAL
		@@ -1427,6 +1442,15 @@ config LOCKD_V4
		config EXPORTFS
		tristate

		config NFS_ACL_SUPPORT
		tristate
		select FS_POSIX_ACL

		config NFS_COMMON
		bool
		depends on NFSD \|\| NFS_FS
		default y

		config SUNRPC
		tristate

fs/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@ obj-$(CONFIG_BINFMT_FLAT) += binfmt_flat.o

		obj-$(CONFIG_FS_MBCACHE) += mbcache.o
		obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o xattr_acl.o
		obj-$(CONFIG_NFS_COMMON) += nfs_common/

		obj-$(CONFIG_QUOTA) += dquot.o
		obj-$(CONFIG_QFMT_V1) += quota_v1.o

fs/nfs_common/Makefile

0 → 100644

+7 −0

Original line number	Diff line number	Diff line
		#
		# Makefile for Linux filesystem routines that are shared by client and server.
		#

		obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o

		nfs_acl-objs := nfsacl.o

fs/nfs_common/nfsacl.c

0 → 100644

+257 −0

Original line number	Diff line number	Diff line
		/*
		* fs/nfs_common/nfsacl.c
		*
		* Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
		*/

		/*
		* The Solaris nfsacl protocol represents some ACLs slightly differently
		* than POSIX 1003.1e draft 17 does (and we do):
		*
		* - Minimal ACLs always have an ACL_MASK entry, so they have
		* four instead of three entries.
		* - The ACL_MASK entry in such minimal ACLs always has the same
		* permissions as the ACL_GROUP_OBJ entry. (In extended ACLs
		* the ACL_MASK and ACL_GROUP_OBJ entries may differ.)
		* - The identifier fields of the ACL_USER_OBJ and ACL_GROUP_OBJ
		* entries contain the identifiers of the owner and owning group.
		* (In POSIX ACLs we always set them to ACL_UNDEFINED_ID).
		* - ACL entries in the kernel are kept sorted in ascending order
		* of (e_tag, e_id). Solaris ACLs are unsorted.
		*/

		#include <linux/module.h>
		#include <linux/fs.h>
		#include <linux/sunrpc/xdr.h>
		#include <linux/nfsacl.h>
		#include <linux/nfs3.h>
		#include <linux/sort.h>

		MODULE_LICENSE("GPL");

		EXPORT_SYMBOL(nfsacl_encode);
		EXPORT_SYMBOL(nfsacl_decode);

		struct nfsacl_encode_desc {
		struct xdr_array2_desc desc;
		unsigned int count;
		struct posix_acl *acl;
		int typeflag;
		uid_t uid;
		gid_t gid;
		};

		static int
		xdr_nfsace_encode(struct xdr_array2_desc desc, void elem)
		{
		struct nfsacl_encode_desc *nfsacl_desc =
		(struct nfsacl_encode_desc *) desc;
		u32 p = (u32 ) elem;

		if (nfsacl_desc->count < nfsacl_desc->acl->a_count) {
		struct posix_acl_entry *entry =
		&nfsacl_desc->acl->a_entries[nfsacl_desc->count++];

		*p++ = htonl(entry->e_tag \| nfsacl_desc->typeflag);
		switch(entry->e_tag) {
		case ACL_USER_OBJ:
		*p++ = htonl(nfsacl_desc->uid);
		break;
		case ACL_GROUP_OBJ:
		*p++ = htonl(nfsacl_desc->gid);
		break;
		case ACL_USER:
		case ACL_GROUP:
		*p++ = htonl(entry->e_id);
		break;
		default: /* Solaris depends on that! */
		*p++ = 0;
		break;
		}
		*p++ = htonl(entry->e_perm & S_IRWXO);
		} else {
		const struct posix_acl_entry pa, pe;
		int group_obj_perm = ACL_READ\|ACL_WRITE\|ACL_EXECUTE;

		FOREACH_ACL_ENTRY(pa, nfsacl_desc->acl, pe) {
		if (pa->e_tag == ACL_GROUP_OBJ) {
		group_obj_perm = pa->e_perm & S_IRWXO;
		break;
		}
		}
		/* fake up ACL_MASK entry */
		*p++ = htonl(ACL_MASK \| nfsacl_desc->typeflag);
		*p++ = htonl(0);
		*p++ = htonl(group_obj_perm);
		}

		return 0;
		}

		unsigned int
		nfsacl_encode(struct xdr_buf buf, unsigned int base, struct inode inode,
		struct posix_acl *acl, int encode_entries, int typeflag)
		{
		int entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0;
		struct nfsacl_encode_desc nfsacl_desc = {
		.desc = {
		.elem_size = 12,
		.array_len = encode_entries ? entries : 0,
		.xcode = xdr_nfsace_encode,
		},
		.acl = acl,
		.typeflag = typeflag,
		.uid = inode->i_uid,
		.gid = inode->i_gid,
		};
		int err;

		if (entries > NFS_ACL_MAX_ENTRIES \|\|
		xdr_encode_word(buf, base, entries))
		return -EINVAL;
		err = xdr_encode_array2(buf, base + 4, &nfsacl_desc.desc);
		if (!err)
		err = 8 + nfsacl_desc.desc.elem_size *
		nfsacl_desc.desc.array_len;
		return err;
		}

		struct nfsacl_decode_desc {
		struct xdr_array2_desc desc;
		unsigned int count;
		struct posix_acl *acl;
		};

		static int
		xdr_nfsace_decode(struct xdr_array2_desc desc, void elem)
		{
		struct nfsacl_decode_desc *nfsacl_desc =
		(struct nfsacl_decode_desc *) desc;
		u32 p = (u32 ) elem;
		struct posix_acl_entry *entry;

		if (!nfsacl_desc->acl) {
		if (desc->array_len > NFS_ACL_MAX_ENTRIES)
		return -EINVAL;
		nfsacl_desc->acl = posix_acl_alloc(desc->array_len, GFP_KERNEL);
		if (!nfsacl_desc->acl)
		return -ENOMEM;
		nfsacl_desc->count = 0;
		}

		entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
		entry->e_tag = ntohl(*p++) & ~NFS_ACL_DEFAULT;
		entry->e_id = ntohl(*p++);
		entry->e_perm = ntohl(*p++);

		switch(entry->e_tag) {
		case ACL_USER_OBJ:
		case ACL_USER:
		case ACL_GROUP_OBJ:
		case ACL_GROUP:
		case ACL_OTHER:
		if (entry->e_perm & ~S_IRWXO)
		return -EINVAL;
		break;
		case ACL_MASK:
		/* Solaris sometimes sets additonal bits in the mask */
		entry->e_perm &= S_IRWXO;
		break;
		default:
		return -EINVAL;
		}

		return 0;
		}

		static int
		cmp_acl_entry(const void x, const void y)
		{
		const struct posix_acl_entry a = x, b = y;

		if (a->e_tag != b->e_tag)
		return a->e_tag - b->e_tag;
		else if (a->e_id > b->e_id)
		return 1;
		else if (a->e_id < b->e_id)
		return -1;
		else
		return 0;
		}

		/*
		* Convert from a Solaris ACL to a POSIX 1003.1e draft 17 ACL.
		*/
		static int
		posix_acl_from_nfsacl(struct posix_acl *acl)
		{
		struct posix_acl_entry pa, pe,
		group_obj = NULL, mask = NULL;

		if (!acl)
		return 0;

		sort(acl->a_entries, acl->a_count, sizeof(struct posix_acl_entry),
		cmp_acl_entry, NULL);

		/* Clear undefined identifier fields and find the ACL_GROUP_OBJ
		and ACL_MASK entries. */
		FOREACH_ACL_ENTRY(pa, acl, pe) {
		switch(pa->e_tag) {
		case ACL_USER_OBJ:
		pa->e_id = ACL_UNDEFINED_ID;
		break;
		case ACL_GROUP_OBJ:
		pa->e_id = ACL_UNDEFINED_ID;
		group_obj = pa;
		break;
		case ACL_MASK:
		mask = pa;
		/* fall through */
		case ACL_OTHER:
		pa->e_id = ACL_UNDEFINED_ID;
		break;
		}
		}
		if (acl->a_count == 4 && group_obj && mask &&
		mask->e_perm == group_obj->e_perm) {
		/* remove bogus ACL_MASK entry */
		memmove(mask, mask+1, (3 - (mask - acl->a_entries)) *
		sizeof(struct posix_acl_entry));
		acl->a_count = 3;
		}
		return 0;
		}

		unsigned int
		nfsacl_decode(struct xdr_buf buf, unsigned int base, unsigned int aclcnt,
		struct posix_acl **pacl)
		{
		struct nfsacl_decode_desc nfsacl_desc = {
		.desc = {
		.elem_size = 12,
		.xcode = pacl ? xdr_nfsace_decode : NULL,
		},
		};
		u32 entries;
		int err;

		if (xdr_decode_word(buf, base, &entries) \|\|
		entries > NFS_ACL_MAX_ENTRIES)
		return -EINVAL;
		err = xdr_decode_array2(buf, base + 4, &nfsacl_desc.desc);
		if (err)
		return err;
		if (pacl) {
		if (entries != nfsacl_desc.desc.array_len \|\|
		posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) {
		posix_acl_release(nfsacl_desc.acl);
		return -EINVAL;
		}
		*pacl = nfsacl_desc.acl;
		}
		if (aclcnt)
		*aclcnt = entries;
		return 8 + nfsacl_desc.desc.elem_size *
		nfsacl_desc.desc.array_len;
		}

fs/nfsd/Makefile

+2 −0

Original line number	Diff line number	Diff line
		@@ -6,7 +6,9 @@ obj-$(CONFIG_NFSD) += nfsd.o

		nfsd-y := nfssvc.o nfsctl.o nfsproc.o nfsfh.o vfs.o \
		export.o auth.o lockd.o nfscache.o nfsxdr.o stats.o
		nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o
		nfsd-$(CONFIG_NFSD_V3) += nfs3proc.o nfs3xdr.o
		nfsd-$(CONFIG_NFSD_V3_ACL) += nfs3acl.o
		nfsd-$(CONFIG_NFSD_V4) += nfs4proc.o nfs4xdr.o nfs4state.o nfs4idmap.o \
		nfs4acl.o nfs4callback.o
		nfsd-objs := $(nfsd-y)