NFS do not find client in NFSv4 pg_authenticate

The information required to find the nfs_client cooresponding to the incoming
back channel request is contained in the NFS layer. Perform minimal checking
in the RPC layer pg_authenticate method, and push more detailed checking into
the NFS layer where the nfs_client can be found.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

7 files changed, 41 insertions, 111 deletions

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 199016528fcb..e3d294269058 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -135,33 +135,6 @@ out_err:
 
 #if defined(CONFIG_NFS_V4_1)
 /*
- *  * CB_SEQUENCE operations will fail until the callback sessionid is set.
- *   */
-int nfs4_set_callback_sessionid(struct nfs_client *clp)
-{
-        struct svc_serv *serv = clp->cl_rpcclient->cl_xprt->bc_serv;
-        struct nfs4_sessionid *bc_sid;
-
-        if (!serv->sv_bc_xprt)
-                return -EINVAL;
-
-        /* on success freed in xprt_free */
-        bc_sid = kmalloc(sizeof(struct nfs4_sessionid), GFP_KERNEL);
-        if (!bc_sid)
-                return -ENOMEM;
-        memcpy(bc_sid->data, &clp->cl_session->sess_id.data,
-                NFS4_MAX_SESSIONID_LEN);
-        spin_lock_bh(&serv->sv_cb_lock);
-        serv->sv_bc_xprt->xpt_bc_sid = bc_sid;
-        spin_unlock_bh(&serv->sv_cb_lock);
-        dprintk("%s set xpt_bc_sid=%u:%u:%u:%u for sv_bc_xprt %p\n", __func__,
-                ((u32 *)bc_sid->data)[0], ((u32 *)bc_sid->data)[1],
-                ((u32 *)bc_sid->data)[2], ((u32 *)bc_sid->data)[3],
-                serv->sv_bc_xprt);
-        return 0;
-}
-
-/*
  * The callback service for NFSv4.1 callbacks
  */
 static int
@@ -266,10 +239,6 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
                 struct nfs_callback_data *cb_info)
 {
 }
-int nfs4_set_callback_sessionid(struct nfs_client *clp)
-{
-        return 0;
-}
 #endif /* CONFIG_NFS_V4_1 */
 
 /*
@@ -359,78 +328,58 @@ void nfs_callback_down(int minorversion)
         mutex_unlock(&nfs_callback_mutex);
 }
 
-static int check_gss_callback_principal(struct nfs_client *clp,
-                                        struct svc_rqst *rqstp)
+/* Boolean check of RPC_AUTH_GSS principal */
+int
+check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
 {
         struct rpc_clnt *r = clp->cl_rpcclient;
         char *p = svc_gss_principal(rqstp);
 
+        if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
+                return 1;
+
         /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
         if (clp->cl_minorversion != 0)
-                return SVC_DROP;
+                return 0;
         /*
          * It might just be a normal user principal, in which case
          * userspace won't bother to tell us the name at all.
          */
         if (p == NULL)
-                return SVC_DENIED;
+                return 0;
 
         /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
 
         if (memcmp(p, "nfs@", 4) != 0)
-                return SVC_DENIED;
+                return 0;
         p += 4;
         if (strcmp(p, r->cl_server) != 0)
-                return SVC_DENIED;
-        return SVC_OK;
+                return 0;
+        return 1;
 }
 
-/* pg_authenticate method helper */
-static struct nfs_client *nfs_cb_find_client(struct svc_rqst *rqstp)
-{
-        struct nfs4_sessionid *sessionid = bc_xprt_sid(rqstp);
-        int is_cb_compound = rqstp->rq_proc == CB_COMPOUND ? 1 : 0;
-
-        dprintk("--> %s rq_proc %d\n", __func__, rqstp->rq_proc);
-        if (svc_is_backchannel(rqstp))
-                /* Sessionid (usually) set after CB_NULL ping */
-                return nfs4_find_client_sessionid(svc_addr(rqstp), sessionid,
-                                                  is_cb_compound);
-        else
-                /* No callback identifier in pg_authenticate */
-                return nfs4_find_client_no_ident(svc_addr(rqstp));
-}
-
-/* pg_authenticate method for nfsv4 callback threads. */
+/*
+ * pg_authenticate method for nfsv4 callback threads.
+ *
+ * The authflavor has been negotiated, so an incorrect flavor is a server
+ * bug. Drop packets with incorrect authflavor.
+ *
+ * All other checking done after NFS decoding where the nfs_client can be
+ * found in nfs4_callback_compound
+ */
 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
 {
-        struct nfs_client *clp;
-        RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
-        int ret = SVC_OK;
-
-        /* Don't talk to strangers */
-        clp = nfs_cb_find_client(rqstp);
-        if (clp == NULL)
-                return SVC_DROP;
-
-        dprintk("%s: %s NFSv4 callback!\n", __func__,
-                        svc_print_addr(rqstp, buf, sizeof(buf)));
-
         switch (rqstp->rq_authop->flavour) {
-                case RPC_AUTH_NULL:
-                        if (rqstp->rq_proc != CB_NULL)
-                                ret = SVC_DENIED;
-                        break;
-                case RPC_AUTH_UNIX:
-                        break;
-                case RPC_AUTH_GSS:
-                        ret = check_gss_callback_principal(clp, rqstp);
-                        break;
-                default:
-                        ret = SVC_DENIED;
+        case RPC_AUTH_NULL:
+                if (rqstp->rq_proc != CB_NULL)
+                        return SVC_DROP;
+                break;
+        case RPC_AUTH_GSS:
+                /* No RPC_AUTH_GSS support yet in NFSv4.1 */
+                 if (svc_is_backchannel(rqstp))
+                        return SVC_DROP;
         }
-        nfs_put_client(clp);
-        return ret;
+        return SVC_OK;
 }
 
 /*
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index d3b44f9bd747..46d93ce7311b 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -7,6 +7,7 @@
  */
 #ifndef __LINUX_FS_NFS_CALLBACK_H
 #define __LINUX_FS_NFS_CALLBACK_H
+#include <linux/sunrpc/svc.h>
 
 #define NFS4_CALLBACK 0x40000000
 #define NFS4_CALLBACK_XDRSIZE 2048
@@ -37,7 +38,6 @@ enum nfs4_callback_opnum {
 struct cb_process_state {
         __be32                  drc_status;
         struct nfs_client       *clp;
-        struct nfs4_sessionid   *svc_sid; /* v4.1 callback service sessionid */
 };
 
 struct cb_compound_hdr_arg {
@@ -168,7 +168,7 @@ extern unsigned nfs4_callback_layoutrecall(
 extern void nfs4_check_drain_bc_complete(struct nfs4_session *ses);
 extern void nfs4_cb_take_slot(struct nfs_client *clp);
 #endif /* CONFIG_NFS_V4_1 */
-
+extern int check_gss_callback_principal(struct nfs_client *, struct svc_rqst *);
 extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
                                     struct cb_getattrres *res,
                                     struct cb_process_state *cps);
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 4bb91cb2620d..829f406e91dd 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -373,17 +373,11 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
 {
         struct nfs_client *clp;
         int i;
-        __be32 status;
+        __be32 status = htonl(NFS4ERR_BADSESSION);
 
         cps->clp = NULL;
 
-        status = htonl(NFS4ERR_BADSESSION);
-        /* Incoming session must match the callback session */
-        if (memcmp(&args->csa_sessionid, cps->svc_sid, NFS4_MAX_SESSIONID_LEN))
-                goto out;
-
-        clp = nfs4_find_client_sessionid(args->csa_addr,
-                                         &args->csa_sessionid, 1);
+        clp = nfs4_find_client_sessionid(args->csa_addr, &args->csa_sessionid);
         if (clp == NULL)
                 goto out;
 
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index 23112c263f81..14e0f9371d14 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -794,10 +794,9 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r
 
         if (hdr_arg.minorversion == 0) {
                 cps.clp = nfs4_find_client_ident(hdr_arg.cb_ident);
-                if (!cps.clp)
+                if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
                         return rpc_drop_reply;
-        } else
-                cps.svc_sid = bc_xprt_sid(rqstp);
+        }
 
         hdr_res.taglen = hdr_arg.taglen;
         hdr_res.tag = hdr_arg.tag;
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 192f2f860265..bd3ca32879e7 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1206,16 +1206,11 @@ nfs4_find_client_ident(int cb_ident)
  * For CB_COMPOUND calls, find a client by IP address, protocol version,
  * minorversion, and sessionID
  *
- * CREATE_SESSION triggers a CB_NULL ping from servers. The callback service
- * sessionid can only be set after the CREATE_SESSION return, so a CB_NULL
- * can arrive before the callback sessionid is set. For CB_NULL calls,
- * find a client by IP address protocol version, and minorversion.
- *
  * Returns NULL if no such client
  */
 struct nfs_client *
 nfs4_find_client_sessionid(const struct sockaddr *addr,
-                           struct nfs4_sessionid *sid, int is_cb_compound)
+                           struct nfs4_sessionid *sid)
 {
         struct nfs_client *clp;
 
@@ -1227,9 +1222,9 @@ nfs4_find_client_sessionid(const struct sockaddr *addr,
                 if (!nfs4_has_session(clp))
                         continue;
 
-                /* Match sessionid unless cb_null call*/
-                if (is_cb_compound && (memcmp(clp->cl_session->sess_id.data,
-                    sid->data, NFS4_MAX_SESSIONID_LEN) != 0))
+                /* Match sessionid*/
+                if (memcmp(clp->cl_session->sess_id.data,
+                    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
                         continue;
 
                 atomic_inc(&clp->cl_count);
@@ -1244,7 +1239,7 @@ nfs4_find_client_sessionid(const struct sockaddr *addr,
 
 struct nfs_client *
 nfs4_find_client_sessionid(const struct sockaddr *addr,
-                           struct nfs4_sessionid *sid, int is_cb_compound)
+                           struct nfs4_sessionid *sid)
 {
         return NULL;
 }
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 4644f04b4b46..cf9fdbdabc67 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -133,8 +133,7 @@ extern void nfs_put_client(struct nfs_client *);
 extern struct nfs_client *nfs4_find_client_no_ident(const struct sockaddr *);
 extern struct nfs_client *nfs4_find_client_ident(int);
 extern struct nfs_client *
-nfs4_find_client_sessionid(const struct sockaddr *, struct nfs4_sessionid *,
-                           int);
+nfs4_find_client_sessionid(const struct sockaddr *, struct nfs4_sessionid *);
 extern struct nfs_server *nfs_create_server(
                                         const struct nfs_parsed_mount_data *,
                                         struct nfs_fh *);
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 2336d532cf66..e6742b57a04c 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -232,12 +232,6 @@ int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
         status = nfs4_proc_create_session(clp);
         if (status != 0)
                 goto out;
-        status = nfs4_set_callback_sessionid(clp);
-        if (status != 0) {
-                printk(KERN_WARNING "Sessionid not set. No callback service\n");
-                nfs_callback_down(1);
-                status = 0;
-        }
         nfs41_setup_state_renewal(clp);
         nfs_mark_client_ready(clp, NFS_CS_READY);
 out: