[PATCH 14/15] svcgss: move init code into separate function

J. Bruce Fields
2007-08-27T20:27:15Z

We've let svcauth_gss_accept() get much too long and hairy. The
RPC_GSS_PROC_INIT and RPC_GSS_PROC_CONTINUE_INIT cases share very little
with the other cases, so it's very natural to split them off into a
separate function.

This will also nicely isolate the piece of code we need to parametrize
to authenticating gss-protected NFSv4 callbacks on behalf of the NFS
client.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---
net/sunrpc/auth_gss/svcauth_gss.c | 144 ++++++++++++++++++++-----------------
1 files changed, 77 insertions(+), 67 deletions(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index dc2f41e..79a507e 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -632,7 +632,8 @@ svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
return 0;
}

-/* Verify the checksum on the header and return SVC_OK on success.
+/*
+ * Verify the checksum on the header and return SVC_OK on success.
* Otherwise, return SVC_DROP (in the case of a bad sequence number)
* or return SVC_DENIED and indicate error in authp.
*/
@@ -962,6 +963,78 @@ gss_write_init_verf(struct svc_rqst *rqstp, struct rsi *rsip)
}

/*
+ * Having read the cred already and found we're in the context
+ * initiation case, read the verifier and initiate (or check the results
+ * of) upcalls to userspace for help with context initiation. If
+ * the upcall results are available, write the verifier and result.
+ * Otherwise, drop the request pending an answer to the upcall.
+ */
+static int svcauth_gss_handle_init(struct svc_rqst *rqstp,
+ struct rpc_gss_wire_cred *gc, __be32 *authp)
+{
+ struct kvec *argv = &rqstp->rq_arg.head[0];
+ struct kvec *resv = &rqstp->rq_res.head[0];
+ struct xdr_netobj tmpobj;
+ struct rsi *rsip, rsikey;
+
+ /* Read the verifier; should be NULL: */
+ *authp = rpc_autherr_badverf;
+ if (argv->iov_len < 2 * 4)
+ return SVC_DENIED;
+ if (svc_getnl(argv) != RPC_AUTH_NULL)
+ return SVC_DENIED;
+ if (svc_getnl(argv) != 0)
+ return SVC_DENIED;
+
+ /* Martial context handle and token for upcall: */
+ *authp = rpc_autherr_badcred;
+ if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
+ return SVC_DENIED;
+ memset(&rsikey, 0, sizeof(rsikey));
+ if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
+ return SVC_DROP;
+ *authp = rpc_autherr_badverf;
+ if (svc_safe_getnetobj(argv, &tmpobj)) {
+ kfree(rsikey.in_handle.data);
+ return SVC_DENIED;
+ }
+ if (dup_netobj(&rsikey.in_token, &tmpobj)) {
+ kfree(rsikey.in_handle.data);
+ return SVC_DROP;
+ }
+
+ /* Perform upcall, or find upcall result: */
+ rsip = rsi_lookup(&rsikey);
+ rsi_free(&rsikey);
+ if (!rsip)
+ return SVC_DROP;
+ switch (cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) {
+ case -EAGAIN:
+ case -ETIMEDOUT:
+ case -ENOENT:
+ /* No upcall result: */
+ return SVC_DROP;
+ case 0:
+ /* Got an answer to the upcall; use it: */
+ if (gss_write_init_verf(rqstp, rsip))
+ return SVC_DROP;
+ if (resv->iov_len + 4 > PAGE_SIZE)
+ return SVC_DROP;
+ svc_putnl(resv, RPC_SUCCESS);
+ if (svc_safe_putnetobj(resv, &rsip->out_handle))
+ return SVC_DROP;
+ if (resv->iov_len + 3 * 4 > PAGE_SIZE)
+ return SVC_DROP;
+ svc_putnl(resv, rsip->major_status);
+ svc_putnl(resv, rsip->minor_status);
+ svc_putnl(resv, GSS_SEQ_WIN);
+ if (svc_safe_putnetobj(resv, &rsip->out_token))
+ return SVC_DROP;
+ }
+ return SVC_COMPLETE;
+}
+
+/*
* Accept an rpcsec packet.
* If context establishment, punt to user space
* If data exchange, verify/decrypt
@@ -975,11 +1048,9 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
struct kvec *argv = &rqstp->rq_arg.head[0];
struct kvec *resv = &rqstp->rq_res.head[0];
u32 crlen;
- struct xdr_netobj tmpobj;
struct gss_svc_data *svcdata = rqstp->rq_auth_data;
struct rpc_gss_wire_cred *gc;
struct rsc *rsci = NULL;
- struct rsi *rsip, rsikey;
__be32 *rpcstart;
__be32 *reject_stat = resv->iov_base + resv->iov_len;
int ret;
@@ -1024,30 +1095,14 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
goto auth_err;

- /*
- * We've successfully parsed the credential. Let's check out the
- * verifier. An AUTH_NULL verifier is allowed (and required) for
- * INIT and CONTINUE_INIT requests. AUTH_RPCSEC_GSS is required for
- * PROC_DATA and PROC_DESTROY.
- *
- * AUTH_NULL verifier is 0 (AUTH_NULL), 0 (length).
- * AUTH_RPCSEC_GSS verifier is:
- * 6 (AUTH_RPCSEC_GSS), length, checksum.
- * checksum is calculated over rpcheader from xid up to here.
- */
*authp = rpc_autherr_badverf;
switch (gc->gc_proc) {
case RPC_GSS_PROC_INIT:
case RPC_GSS_PROC_CONTINUE_INIT:
- if (argv->iov_len < 2 * 4)
- goto auth_err;
- if (svc_getnl(argv) != RPC_AUTH_NULL)
- goto auth_err;
- if (svc_getnl(argv) != 0)
- goto auth_err;
- break;
+ return svcauth_gss_handle_init(rqstp, gc, authp);
case RPC_GSS_PROC_DATA:
case RPC_GSS_PROC_DESTROY:
+ /* Look up the context, and check the verifier: */
*authp = rpcsec_gsserr_credproblem;
rsci = gss_svc_searchbyctx(&gc->gc_ctx);
if (!rsci)
@@ -1068,51 +1123,6 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)

/* now act upon the command: */
switch (gc->gc_proc) {
- case RPC_GSS_PROC_INIT:
- case RPC_GSS_PROC_CONTINUE_INIT:
- *authp = rpc_autherr_badcred;
- if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
- goto auth_err;
- memset(&rsikey, 0, sizeof(rsikey));
- if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
- goto drop;
- *authp = rpc_autherr_badverf;
- if (svc_safe_getnetobj(argv, &tmpobj)) {
- kfree(rsikey.in_handle.data);
- goto auth_err;
- }
- if (dup_netobj(&rsikey.in_token, &tmpobj)) {
- kfree(rsikey.in_handle.data);
- goto drop;
- }
-
- rsip = rsi_lookup(&rsikey);
- rsi_free(&rsikey);
- if (!rsip) {
- goto drop;
- }
- switch(cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) {
- case -EAGAIN:
- case -ETIMEDOUT:
- case -ENOENT:
- goto drop;
- case 0:
- if (gss_write_init_verf(rqstp, rsip))
- goto drop;
- if (resv->iov_len + 4 > PAGE_SIZE)
- goto drop;
- svc_putnl(resv, RPC_SUCCESS);
- if (svc_safe_putnetobj(resv, &rsip->out_handle))
- goto drop;
- if (resv->iov_len + 3 * 4 > PAGE_SIZE)
- goto drop;
- svc_putnl(resv, rsip->major_status);
- svc_putnl(resv, rsip->minor_status);
- svc_putnl(resv, GSS_SEQ_WIN);
- if (svc_safe_putnetobj(resv, &rsip->out_token))
- goto drop;
- }
- goto complete;
case RPC_GSS_PROC_DESTROY:
if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
goto auth_err;
@@ -1159,7 +1169,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
goto out;
}
auth_err:
- /* Restore write pointer to original value: */
+ /* Restore write pointer to its original value: */
xdr_ressize_check(rqstp, reject_stat);
ret = SVC_DENIED;
goto out;
--
1.5.3.rc5.19.g0734d