knfsd: nfsd4: implement secinfo

Implement the secinfo operation.

(Thanks to Usha Ketineni wrote an earlier version of this support.)

Cc: Usha Ketineni <uketinen@us.ibm.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 113 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index a106e3be7c13..3c627128e205 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -47,6 +47,7 @@
 #include <linux/nfsd/state.h>
 #include <linux/nfsd/xdr4.h>
 #include <linux/nfs4_acl.h>
+#include <linux/sunrpc/gss_api.h>
 
 #define NFSDDBG_FACILITY                NFSDDBG_PROC
 
@@ -610,6 +611,30 @@ nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 }
 
 static __be32
+nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+              struct nfsd4_secinfo *secinfo)
+{
+        struct svc_fh resfh;
+        struct svc_export *exp;
+        struct dentry *dentry;
+        __be32 err;
+
+        fh_init(&resfh, NFS4_FHSIZE);
+        err = nfsd_lookup_dentry(rqstp, &cstate->current_fh,
+                                    secinfo->si_name, secinfo->si_namelen,
+                                    &exp, &dentry);
+        if (err)
+                return err;
+        if (dentry->d_inode == NULL) {
+                exp_put(exp);
+                err = nfserr_noent;
+        } else
+                secinfo->si_exp = exp;
+        dput(dentry);
+        return err;
+}
+
+static __be32
 nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
               struct nfsd4_setattr *setattr)
 {
@@ -1008,6 +1033,9 @@ static struct nfsd4_operation nfsd4_ops[OP_RELEASE_LOCKOWNER+1] = {
         [OP_SAVEFH] = {
                 .op_func = (nfsd4op_func)nfsd4_savefh,
         },
+        [OP_SECINFO] = {
+                .op_func = (nfsd4op_func)nfsd4_secinfo,
+        },
         [OP_SETATTR] = {
                 .op_func = (nfsd4op_func)nfsd4_setattr,
         },
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b0bfbda375e1..864498f8f2d9 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -56,6 +56,7 @@
 #include <linux/nfsd_idmap.h>
 #include <linux/nfs4.h>
 #include <linux/nfs4_acl.h>
+#include <linux/sunrpc/gss_api.h>
 
 #define NFSDDBG_FACILITY                NFSDDBG_XDR
 
@@ -819,6 +820,23 @@ nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
 }
 
 static __be32
+nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
+                     struct nfsd4_secinfo *secinfo)
+{
+        DECODE_HEAD;
+
+        READ_BUF(4);
+        READ32(secinfo->si_namelen);
+        READ_BUF(secinfo->si_namelen);
+        SAVEMEM(secinfo->si_name, secinfo->si_namelen);
+        status = check_filename(secinfo->si_name, secinfo->si_namelen,
+                                                                nfserr_noent);
+        if (status)
+                return status;
+        DECODE_TAIL;
+}
+
+static __be32
 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
 {
         DECODE_HEAD;
@@ -1131,6 +1149,9 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
                 case OP_SAVEFH:
                         op->status = nfs_ok;
                         break;
+                case OP_SECINFO:
+                        op->status = nfsd4_decode_secinfo(argp, &op->u.secinfo);
+                        break;
                 case OP_SETATTR:
                         op->status = nfsd4_decode_setattr(argp, &op->u.setattr);
                         break;
@@ -1847,11 +1868,19 @@ nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
         if (d_mountpoint(dentry)) {
                 int err;
 
+                /*
+                 * Why the heck aren't we just using nfsd_lookup??
+                 * Different "."/".." handling?  Something else?
+                 * At least, add a comment here to explain....
+                 */
                 err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
                 if (err) {
                         nfserr = nfserrno(err);
                         goto out_put;
                 }
+                nfserr = check_nfsd_access(exp, cd->rd_rqstp);
+                if (nfserr)
+                        goto out_put;
 
         }
         nfserr = nfsd4_encode_fattr(NULL, exp, dentry, p, buflen, cd->rd_bmval,
@@ -2419,6 +2448,49 @@ nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
         }
 }
 
+static void
+nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, int nfserr,
+                     struct nfsd4_secinfo *secinfo)
+{
+        int i = 0;
+        struct svc_export *exp = secinfo->si_exp;
+        ENCODE_HEAD;
+
+        if (nfserr)
+                goto out;
+        RESERVE_SPACE(4);
+        WRITE32(exp->ex_nflavors);
+        ADJUST_ARGS();
+        for (i = 0; i < exp->ex_nflavors; i++) {
+                u32 flav = exp->ex_flavors[i].pseudoflavor;
+                struct gss_api_mech *gm = gss_mech_get_by_pseudoflavor(flav);
+
+                if (gm) {
+                        RESERVE_SPACE(4);
+                        WRITE32(RPC_AUTH_GSS);
+                        ADJUST_ARGS();
+                        RESERVE_SPACE(4 + gm->gm_oid.len);
+                        WRITE32(gm->gm_oid.len);
+                        WRITEMEM(gm->gm_oid.data, gm->gm_oid.len);
+                        ADJUST_ARGS();
+                        RESERVE_SPACE(4);
+                        WRITE32(0); /* qop */
+                        ADJUST_ARGS();
+                        RESERVE_SPACE(4);
+                        WRITE32(gss_pseudoflavor_to_service(gm, flav));
+                        ADJUST_ARGS();
+                        gss_mech_put(gm);
+                } else {
+                        RESERVE_SPACE(4);
+                        WRITE32(flav);
+                        ADJUST_ARGS();
+                }
+        }
+out:
+        if (exp)
+                exp_put(exp);
+}
+
 /*
  * The SETATTR encode routine is special -- it always encodes a bitmap,
  * regardless of the error status.
@@ -2559,6 +2631,9 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
                 break;
         case OP_SAVEFH:
                 break;
+        case OP_SECINFO:
+                nfsd4_encode_secinfo(resp, op->status, &op->u.secinfo);
+                break;
         case OP_SETATTR:
                 nfsd4_encode_setattr(resp, op->status, &op->u.setattr);
                 break;
diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
index 54ef1a18a56c..e452256d3f72 100644
--- a/include/linux/nfsd/nfsd.h
+++ b/include/linux/nfsd/nfsd.h
@@ -71,6 +71,9 @@ int		nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
                                 struct svc_export **expp);
 __be32          nfsd_lookup(struct svc_rqst *, struct svc_fh *,
                                 const char *, int, struct svc_fh *);
+__be32           nfsd_lookup_dentry(struct svc_rqst *, struct svc_fh *,
+                                const char *, int,
+                                struct svc_export **, struct dentry **);
 __be32          nfsd_setattr(struct svc_rqst *, struct svc_fh *,
                                 struct iattr *, int, time_t);
 #ifdef CONFIG_NFSD_V4
diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
index 09799bcee0ac..1b653267133a 100644
--- a/include/linux/nfsd/xdr4.h
+++ b/include/linux/nfsd/xdr4.h
@@ -293,6 +293,12 @@ struct nfsd4_rename {
         struct nfsd4_change_info  rn_tinfo; /* response */
 };
 
+struct nfsd4_secinfo {
+        u32 si_namelen;                                 /* request */
+        char *si_name;                                  /* request */
+        struct svc_export *si_exp;                      /* response */
+};
+
 struct nfsd4_setattr {
         stateid_t       sa_stateid;         /* request */
         u32             sa_bmval[2];        /* request */
@@ -365,6 +371,7 @@ struct nfsd4_op {
                 struct nfsd4_remove             remove;
                 struct nfsd4_rename             rename;
                 clientid_t                      renew;
+                struct nfsd4_secinfo            secinfo;
                 struct nfsd4_setattr            setattr;
                 struct nfsd4_setclientid        setclientid;
                 struct nfsd4_setclientid_confirm setclientid_confirm;