diff mbox

[13/19] NFSD: Server implementation of MAC Labeling

Message ID 1364939160-20874-14-git-send-email-SteveD@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Steve Dickson April 2, 2013, 9:45 p.m. UTC
From: David Quigley <dpquigl@davequigley.com>

This patch adds the ability to encode and decode file labels on the server for
the purpose of sending them to the client and also to process label change
requests from the client.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
---
 fs/nfsd/nfs4proc.c |  41 +++++++++++++++++++
 fs/nfsd/nfs4xdr.c  | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 fs/nfsd/nfsd.h     |   6 ++-
 fs/nfsd/vfs.c      |  28 +++++++++++++
 fs/nfsd/vfs.h      |   2 +
 fs/nfsd/xdr4.h     |   3 ++
 6 files changed, 190 insertions(+), 6 deletions(-)

Comments

Bruce Fields April 10, 2013, 3:19 p.m. UTC | #1
On Tue, Apr 02, 2013 at 05:45:54PM -0400, Steve Dickson wrote:
> +__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
> +		struct nfs4_label *label)
> +{
> +	return -EOPNOTSUPP;

Anything that returns a __be32 is expecting nfserr_something, not
-ERRNO.

I made the same comment on a previous review:

	http://www.spinics.net/lists/linux-nfs/msg36104.html

Please keep a careful list of these review comments!

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Steve Dickson April 23, 2013, 7:40 p.m. UTC | #2
On 10/04/13 11:19, J. Bruce Fields wrote:
> On Tue, Apr 02, 2013 at 05:45:54PM -0400, Steve Dickson wrote:
>> +__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
>> +		struct nfs4_label *label)
>> +{
>> +	return -EOPNOTSUPP;
> 
> Anything that returns a __be32 is expecting nfserr_something, not
> -ERRNO.
> 
I think it makes sense when label are not configured for this to
return nfserr_notsupp which will then get turned into a -EOPNOTSUPP, 
agreed?
 
steved.

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Bruce Fields April 23, 2013, 7:44 p.m. UTC | #3
On Tue, Apr 23, 2013 at 03:40:43PM -0400, Steve Dickson wrote:
> 
> 
> On 10/04/13 11:19, J. Bruce Fields wrote:
> > On Tue, Apr 02, 2013 at 05:45:54PM -0400, Steve Dickson wrote:
> >> +__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
> >> +		struct nfs4_label *label)
> >> +{
> >> +	return -EOPNOTSUPP;
> > 
> > Anything that returns a __be32 is expecting nfserr_something, not
> > -ERRNO.
> > 
> I think it makes sense when label are not configured for this to
> return nfserr_notsupp which will then get turned into a -EOPNOTSUPP, 
> agreed?

Right though as I've said on previous review really this should be
caught by fs/nfsd/nfs4proc.c:check_attr_support() which is called just
before nfsd4_set_nfs4_label() in nfsd4_setattr().

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Steve Dickson April 23, 2013, 7:51 p.m. UTC | #4
On 23/04/13 15:44, J. Bruce Fields wrote:
> On Tue, Apr 23, 2013 at 03:40:43PM -0400, Steve Dickson wrote:
>>
>>
>> On 10/04/13 11:19, J. Bruce Fields wrote:
>>> On Tue, Apr 02, 2013 at 05:45:54PM -0400, Steve Dickson wrote:
>>>> +__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
>>>> +		struct nfs4_label *label)
>>>> +{
>>>> +	return -EOPNOTSUPP;
>>>
>>> Anything that returns a __be32 is expecting nfserr_something, not
>>> -ERRNO.
>>>
>> I think it makes sense when label are not configured for this to
>> return nfserr_notsupp which will then get turned into a -EOPNOTSUPP, 
>> agreed?
> 
> Right though as I've said on previous review really this should be
> caught by fs/nfsd/nfs4proc.c:check_attr_support() which is called just
> before nfsd4_set_nfs4_label() in nfsd4_setattr().
It will be once I make nfsd_suppattrs2() only give v4.2 attrs 
on 4.2 mounts...

steved.

> 
> --b.
> 
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diff mbox

Patch

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index ae73175..bb17589 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -42,6 +42,36 @@ 
 #include "current_stateid.h"
 #include "netns.h"
 
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#include <linux/security.h>
+
+static inline void
+nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct nfs4_label *label, u32 *bmval)
+{
+	struct inode *inode = resfh->fh_dentry->d_inode;
+	int status;
+
+	mutex_lock(&inode->i_mutex);
+	status = security_inode_setsecctx(resfh->fh_dentry,
+		label->label, label->len);
+	mutex_unlock(&inode->i_mutex);
+
+	if (status)
+		/*
+		 * We should probably fail the whole open at this point,
+		 * but we've already created or opened the file, so it's 
+		 * too late; So this seems the least of evils:
+		 */
+		bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+		
+	return;
+}
+#else 
+static inline void 
+nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct nfs4_label *label, u32 *bmval)
+{ }
+#endif
+
 #define NFSDDBG_FACILITY		NFSDDBG_PROC
 
 static u32 nfsd_attrmask[] = {
@@ -230,6 +260,9 @@  do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 					(u32 *)open->op_verf.data,
 					&open->op_truncate, &open->op_created);
 
+		if (!status && open->op_label != NULL) 
+			nfsd4_security_inode_setsecctx(resfh, open->op_label, open->op_bmval);
+
 		/*
 		 * Following rfc 3530 14.2.16, use the returned bitmask
 		 * to indicate which attributes we used to store the
@@ -599,6 +632,9 @@  nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	if (status)
 		goto out;
 
+	if (create->cr_label != NULL)
+		nfsd4_security_inode_setsecctx(&resfh, create->cr_label, create->cr_bmval);
+
 	if (create->cr_acl != NULL)
 		do_set_nfs4_acl(rqstp, &resfh, create->cr_acl,
 				create->cr_bmval);
@@ -888,6 +924,11 @@  nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 					    setattr->sa_acl);
 	if (status)
 		goto out;
+	if (setattr->sa_label != NULL)
+		status = nfsd4_set_nfs4_label(rqstp, &cstate->current_fh,
+				setattr->sa_label);
+	if (status)
+		goto out;
 	status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr,
 				0, (time_t)0);
 out:
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0116886..5d06d08 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -55,6 +55,11 @@ 
 #include "cache.h"
 #include "netns.h"
 
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#include <linux/security.h>
+#endif
+
+
 #define NFSDDBG_FACILITY		NFSDDBG_XDR
 
 /*
@@ -79,6 +84,24 @@  check_filename(char *str, int len)
 			return nfserr_badname;
 	return 0;
 }
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+static struct nfs4_label *nfsd4_label_alloc(u32 len)
+{
+	struct nfs4_label *label = NULL;
+
+	if (len > NFS4_MAXLABELLEN)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	label = kzalloc(len + sizeof(struct nfs4_label), GFP_KERNEL);
+	if (label == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	label->label = (char *)(label + 1);
+	label->len = len;
+
+	return label;
+}
+#endif
 
 #define DECODE_HEAD				\
 	__be32 *p;				\
@@ -242,7 +265,8 @@  nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
 
 static __be32
 nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
-		   struct iattr *iattr, struct nfs4_acl **acl)
+		   struct iattr *iattr, struct nfs4_acl **acl,
+		   struct nfs4_label **label)
 {
 	int expected_len, len = 0;
 	u32 dummy32;
@@ -386,6 +410,38 @@  nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
 			goto xdr_error;
 		}
 	}
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
+		uint32_t pi;
+		uint32_t lfs;
+
+		READ_BUF(4);
+		len += 4;
+		READ32(lfs);
+		READ_BUF(4);
+		len += 4;
+		READ32(pi);
+		READ_BUF(4);
+		len += 4;
+		READ32(dummy32);
+		READ_BUF(dummy32);
+		len += (XDR_QUADLEN(dummy32) << 2);
+		READMEM(buf, dummy32);
+
+		*label = nfsd4_label_alloc(dummy32);
+		if (IS_ERR(*label)) {
+			host_err = PTR_ERR(*label);
+			goto out_nfserr;
+		}
+
+		memcpy((*label)->label, buf, (*label)->len);
+		((char *)(*label)->label)[(*label)->len] = '\0';
+		(*label)->pi = pi;
+		(*label)->lfs = lfs;
+
+		defer_free(argp, kfree, *label);
+	}
+#endif
 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2)
@@ -582,7 +638,7 @@  nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create
 		return status;
 
 	status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr,
-				    &create->cr_acl);
+				    &create->cr_acl, &create->cr_label);
 	if (status)
 		goto out;
 
@@ -832,7 +888,7 @@  nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
 		case NFS4_CREATE_UNCHECKED:
 		case NFS4_CREATE_GUARDED:
 			status = nfsd4_decode_fattr(argp, open->op_bmval,
-				&open->op_iattr, &open->op_acl);
+				&open->op_iattr, &open->op_acl, &open->op_label);
 			if (status)
 				goto out;
 			break;
@@ -846,7 +902,7 @@  nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
 			READ_BUF(NFS4_VERIFIER_SIZE);
 			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
 			status = nfsd4_decode_fattr(argp, open->op_bmval,
-				&open->op_iattr, &open->op_acl);
+				&open->op_iattr, &open->op_acl, &open->op_label);
 			if (status)
 				goto out;
 			break;
@@ -1068,7 +1124,7 @@  nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *seta
 	if (status)
 		return status;
 	return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr,
-				  &setattr->sa_acl);
+				  &setattr->sa_acl, &setattr->sa_label);
 }
 
 static __be32
@@ -1988,6 +2044,50 @@  nfsd4_encode_aclname(struct svc_rqst *rqstp, struct nfs4_ace *ace,
 			      FATTR4_WORD0_RDATTR_ERROR)
 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
 
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+static inline __be32
+nfsd4_encode_security_label(struct svc_rqst *rqstp, struct dentry *dentry, __be32 **pp, int *buflen)
+{
+	void *context;
+	int err;
+	int len;
+	uint32_t pi = 0;
+	uint32_t lfs = 0;
+	__be32 *p = *pp;
+
+	err = 0;
+	(void)security_inode_getsecctx(dentry->d_inode, &context, &len);
+	if (len < 0)
+		return nfserrno(len);
+
+	if (*buflen < ((XDR_QUADLEN(len) << 2) + 4 + 4 + 4)) {
+		err = nfserr_resource;
+		goto out;
+	}
+
+	/*
+	 * For now we use a 0 here to indicate the null translation; in
+	 * the future we may place a call to translation code here.
+	 */
+	if ((*buflen -= 8) < 0)
+		return nfserr_resource;
+
+	WRITE32(lfs);	
+	WRITE32(pi);
+	p = xdr_encode_opaque(p, context, len);
+	*buflen -= (XDR_QUADLEN(len) << 2) + 4;
+
+	*pp = p;
+out:
+	security_release_secctx(context, len);
+	return err;
+}
+#else
+static inline __be32
+nfsd4_encode_security_label(struct svc_rqst *rqstp, struct dentry *dentry, __be32 **pp, int *buflen)
+{ return 0; }
+#endif
+
 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *rdattr_err)
 {
 	/* As per referral draft:  */
@@ -2438,6 +2538,12 @@  out_acl:
 			get_parent_attributes(exp, &stat);
 		WRITE64(stat.ino);
 	}
+	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
+		status = nfsd4_encode_security_label(rqstp, dentry,
+				&p, &buflen);
+		if (status)
+			goto out;
+	}
 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
 		WRITE32(3);
 		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD0);
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 07a473f..62dc89b 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -311,7 +311,11 @@  void		nfsd_lockd_shutdown(void);
  | FATTR4_WORD1_TIME_DELTA   | FATTR4_WORD1_TIME_METADATA    \
  | FATTR4_WORD1_TIME_MODIFY     | FATTR4_WORD1_TIME_MODIFY_SET | FATTR4_WORD1_MOUNTED_ON_FILEID)
 
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define NFSD4_SUPPORTED_ATTRS_WORD2 FATTR4_WORD2_SECURITY_LABEL
+#else
 #define NFSD4_SUPPORTED_ATTRS_WORD2 0
+#endif
 
 #define NFSD4_1_SUPPORTED_ATTRS_WORD0 \
 	NFSD4_SUPPORTED_ATTRS_WORD0
@@ -350,7 +354,7 @@  static inline u32 nfsd_suppattrs2(u32 minorversion)
 #define NFSD_WRITEABLE_ATTRS_WORD1 \
 	(FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER | FATTR4_WORD1_OWNER_GROUP \
 	| FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET)
-#define NFSD_WRITEABLE_ATTRS_WORD2 0
+#define NFSD_WRITEABLE_ATTRS_WORD2 FATTR4_WORD2_SECURITY_LABEL
 
 #define NFSD_SUPPATTR_EXCLCREAT_WORD0 \
 	NFSD_WRITEABLE_ATTRS_WORD0
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2b2e239..4915dbc 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -28,6 +28,7 @@ 
 #include <asm/uaccess.h>
 #include <linux/exportfs.h>
 #include <linux/writeback.h>
+#include <linux/security.h>
 
 #ifdef CONFIG_NFSD_V3
 #include "xdr3.h"
@@ -621,6 +622,33 @@  int nfsd4_is_junction(struct dentry *dentry)
 		return 0;
 	return 1;
 }
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct nfs4_label *label)
+{
+	__be32 error;
+	int host_error;
+	struct dentry *dentry;
+
+	error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
+	if (error)
+		return error;
+
+	dentry = fhp->fh_dentry;
+
+	mutex_lock(&dentry->d_inode->i_mutex);
+	host_error = security_inode_setsecctx(dentry, label->label, label->len);
+	mutex_unlock(&dentry->d_inode->i_mutex);
+	return nfserrno(host_error);
+}
+#else
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct nfs4_label *label)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 #endif /* defined(CONFIG_NFSD_V4) */
 
 #ifdef CONFIG_NFSD_V3
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index 5b58941..a9d6f0f 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -56,6 +56,8 @@  int nfsd_mountpoint(struct dentry *, struct svc_export *);
 __be32          nfsd4_set_nfs4_acl(struct svc_rqst *, struct svc_fh *,
                     struct nfs4_acl *);
 int             nfsd4_get_nfs4_acl(struct svc_rqst *, struct dentry *, struct nfs4_acl **);
+__be32          nfsd4_set_nfs4_label(struct svc_rqst *, struct svc_fh *,
+		    struct nfs4_label *);
 #endif /* CONFIG_NFSD_V4 */
 __be32		nfsd_create(struct svc_rqst *, struct svc_fh *,
 				char *name, int len, struct iattr *attrs,
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 546f898..132a671 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -118,6 +118,7 @@  struct nfsd4_create {
 	struct iattr	cr_iattr;           /* request */
 	struct nfsd4_change_info  cr_cinfo; /* response */
 	struct nfs4_acl *cr_acl;
+	struct nfs4_label *cr_label;
 };
 #define cr_linklen	u.link.namelen
 #define cr_linkname	u.link.name
@@ -246,6 +247,7 @@  struct nfsd4_open {
 	struct nfs4_file *op_file;          /* used during processing */
 	struct nfs4_ol_stateid *op_stp;	    /* used during processing */
 	struct nfs4_acl *op_acl;
+	struct nfs4_label *op_label;
 };
 #define op_iattr	iattr
 
@@ -330,6 +332,7 @@  struct nfsd4_setattr {
 	u32		sa_bmval[3];        /* request */
 	struct iattr	sa_iattr;           /* request */
 	struct nfs4_acl *sa_acl;
+	struct nfs4_label *sa_label;
 };
 
 struct nfsd4_setclientid {