[PATCH] svcrpc: gss: handle the GSS_S_CONTINUE

Kerberos context initiation is handled in a single round trip, but other
mechanisms (including spkm3) may require more, so we need to handle the
GSS_S_CONTINUE case in svcauth_gss_accept.  Send a null verifier.

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@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 25 insertions, 5 deletions

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index e4ada15ed856..d2ccc7e8faab 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -586,6 +586,20 @@ gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
 }
 
 static int
+gss_write_null_verf(struct svc_rqst *rqstp)
+{
+        u32     *p;
+
+        svc_putu32(rqstp->rq_res.head, htonl(RPC_AUTH_NULL));
+        p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
+        /* don't really need to check if head->iov_len > PAGE_SIZE ... */
+        *p++ = 0;
+        if (!xdr_ressize_check(rqstp, p))
+                return -1;
+        return 0;
+}
+
+static int
 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
 {
         u32                     xdr_seq;
@@ -876,12 +890,18 @@ svcauth_gss_accept(struct svc_rqst *rqstp, u32 *authp)
                 case -ENOENT:
                         goto drop;
                 case 0:
-                        rsci = gss_svc_searchbyctx(&rsip->out_handle);
-                        if (!rsci) {
-                                goto drop;
+                        if (rsip->major_status == GSS_S_COMPLETE) {
+                                rsci = gss_svc_searchbyctx(&rsip->out_handle);
+                                if (!rsci) {
+                                        goto drop;
+                                }
+                                if (gss_write_verf(rqstp, rsci->mechctx,
+                                                        GSS_SEQ_WIN))
+                                        goto drop;
+                        } else {
+                                if (gss_write_null_verf(rqstp))
+                                        goto drop;
                         }
-                        if (gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN))
-                                goto drop;
                         if (resv->iov_len + 4 > PAGE_SIZE)
                                 goto drop;
                         svc_putu32(resv, rpc_success);