SUNRPC: Don't spam gssd with upcall requests when the kerberos key expired
Now that the rpc.gssd daemon can explicitly tell us that the key expired,
we should cache that information to avoid spamming gssd.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 48a7939..8da2a0e 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -57,6 +57,9 @@
static const struct rpc_credops gss_credops;
static const struct rpc_credops gss_nullops;
+#define GSS_RETRY_EXPIRED 5
+static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
+
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
@@ -350,6 +353,24 @@
}
static void
+gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
+{
+ switch (gss_msg->msg.errno) {
+ case 0:
+ if (gss_msg->ctx == NULL)
+ break;
+ clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
+ gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
+ break;
+ case -EKEYEXPIRED:
+ set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
+ }
+ gss_cred->gc_upcall_timestamp = jiffies;
+ gss_cred->gc_upcall = NULL;
+ rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
+}
+
+static void
gss_upcall_callback(struct rpc_task *task)
{
struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
@@ -358,13 +379,9 @@
struct inode *inode = &gss_msg->inode->vfs_inode;
spin_lock(&inode->i_lock);
- if (gss_msg->ctx)
- gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
- else
- task->tk_status = gss_msg->msg.errno;
- gss_cred->gc_upcall = NULL;
- rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
+ gss_handle_downcall_result(gss_cred, gss_msg);
spin_unlock(&inode->i_lock);
+ task->tk_status = gss_msg->msg.errno;
gss_release_msg(gss_msg);
}
@@ -513,18 +530,16 @@
spin_lock(&inode->i_lock);
if (gss_cred->gc_upcall != NULL)
rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
- else if (gss_msg->ctx != NULL) {
- gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
- gss_cred->gc_upcall = NULL;
- rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
- } else if (gss_msg->msg.errno >= 0) {
+ else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
task->tk_timeout = 0;
gss_cred->gc_upcall = gss_msg;
/* gss_upcall_callback will release the reference to gss_upcall_msg */
atomic_inc(&gss_msg->count);
rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
- } else
+ } else {
+ gss_handle_downcall_result(gss_cred, gss_msg);
err = gss_msg->msg.errno;
+ }
spin_unlock(&inode->i_lock);
gss_release_msg(gss_msg);
out:
@@ -1123,6 +1138,23 @@
return 0;
}
+static int gss_cred_is_negative_entry(struct rpc_cred *cred)
+{
+ if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
+ unsigned long now = jiffies;
+ unsigned long begin, expire;
+ struct gss_cred *gss_cred;
+
+ gss_cred = container_of(cred, struct gss_cred, gc_base);
+ begin = gss_cred->gc_upcall_timestamp;
+ expire = begin + gss_expired_cred_retry_delay * HZ;
+
+ if (time_in_range_open(now, begin, expire))
+ return 1;
+ }
+ return 0;
+}
+
/*
* Refresh credentials. XXX - finish
*/
@@ -1132,6 +1164,9 @@
struct rpc_cred *cred = task->tk_msg.rpc_cred;
int ret = 0;
+ if (gss_cred_is_negative_entry(cred))
+ return -EKEYEXPIRED;
+
if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
ret = gss_renew_cred(task);
@@ -1585,5 +1620,11 @@
}
MODULE_LICENSE("GPL");
+module_param_named(expired_cred_retry_delay,
+ gss_expired_cred_retry_delay,
+ uint, 0644);
+MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
+ "the RPC engine retries an expired credential");
+
module_init(init_rpcsec_gss)
module_exit(exit_rpcsec_gss)
