1 files changed, 239 insertions, 56 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 853a414..e630b38 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -72,11 +72,25 @@ struct gss_auth {
 	struct gss_api_mech *mech;
 	enum rpc_gss_svc service;
 	struct rpc_clnt *client;
-	struct dentry *dentry;
+	/*
+	 * There are two upcall pipes; dentry[1], named "gssd", is used
+	 * for the new text-based upcall; dentry[0] is named after the
+	 * mechanism (for example, "krb5") and exists for
+	 * backwards-compatibility with older gssd's.
+	 */
+	struct dentry *dentry[2];
 };
 
+/* pipe_version >= 0 if and only if someone has a pipe open. */
+static int pipe_version = -1;
+static atomic_t pipe_users = ATOMIC_INIT(0);
+static DEFINE_SPINLOCK(pipe_version_lock);
+static struct rpc_wait_queue pipe_version_rpc_waitqueue;
+static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
+
 static void gss_free_ctx(struct gss_cl_ctx *);
-static struct rpc_pipe_ops gss_upcall_ops;
+static struct rpc_pipe_ops gss_upcall_ops_v0;
+static struct rpc_pipe_ops gss_upcall_ops_v1;
 
 static inline struct gss_cl_ctx *
 gss_get_ctx(struct gss_cl_ctx *ctx)
@@ -220,6 +234,7 @@ err:
 	return p;
 }
 
+#define UPCALL_BUF_LEN 128
 
 struct gss_upcall_msg {
 	atomic_t count;
@@ -227,16 +242,41 @@ struct gss_upcall_msg {
 	struct rpc_pipe_msg msg;
 	struct list_head list;
 	struct gss_auth *auth;
+	struct rpc_inode *inode;
 	struct rpc_wait_queue rpc_waitqueue;
 	wait_queue_head_t waitqueue;
 	struct gss_cl_ctx *ctx;
+	char databuf[UPCALL_BUF_LEN];
 };
 
+static int get_pipe_version(void)
+{
+	int ret;
+
+	spin_lock(&pipe_version_lock);
+	if (pipe_version >= 0) {
+		atomic_inc(&pipe_users);
+		ret = pipe_version;
+	} else
+		ret = -EAGAIN;
+	spin_unlock(&pipe_version_lock);
+	return ret;
+}
+
+static void put_pipe_version(void)
+{
+	if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
+		pipe_version = -1;
+		spin_unlock(&pipe_version_lock);
+	}
+}
+
 static void
 gss_release_msg(struct gss_upcall_msg *gss_msg)
 {
 	if (!atomic_dec_and_test(&gss_msg->count))
 		return;
+	put_pipe_version();
 	BUG_ON(!list_empty(&gss_msg->list));
 	if (gss_msg->ctx != NULL)
 		gss_put_ctx(gss_msg->ctx);
@@ -266,8 +306,8 @@ __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 static inline struct gss_upcall_msg *
 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 {
-	struct inode *inode = gss_auth->dentry->d_inode;
-	struct rpc_inode *rpci = RPC_I(inode);
+	struct rpc_inode *rpci = gss_msg->inode;
+	struct inode *inode = &rpci->vfs_inode;
 	struct gss_upcall_msg *old;
 
 	spin_lock(&inode->i_lock);
@@ -293,8 +333,7 @@ __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 static void
 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 {
-	struct gss_auth *gss_auth = gss_msg->auth;
-	struct inode *inode = gss_auth->dentry->d_inode;
+	struct inode *inode = &gss_msg->inode->vfs_inode;
 
 	if (list_empty(&gss_msg->list))
 		return;
@@ -310,7 +349,7 @@ gss_upcall_callback(struct rpc_task *task)
 	struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 			struct gss_cred, gc_base);
 	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
-	struct inode *inode = gss_msg->auth->dentry->d_inode;
+	struct inode *inode = &gss_msg->inode->vfs_inode;
 
 	spin_lock(&inode->i_lock);
 	if (gss_msg->ctx)
@@ -323,22 +362,75 @@ gss_upcall_callback(struct rpc_task *task)
 	gss_release_msg(gss_msg);
 }
 
+static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
+{
+	gss_msg->msg.data = &gss_msg->uid;
+	gss_msg->msg.len = sizeof(gss_msg->uid);
+}
+
+static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
+				struct rpc_clnt *clnt, int machine_cred)
+{
+	char *p = gss_msg->databuf;
+	int len = 0;
+
+	gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
+				   gss_msg->auth->mech->gm_name,
+				   gss_msg->uid);
+	p += gss_msg->msg.len;
+	if (clnt->cl_principal) {
+		len = sprintf(p, "target=%s ", clnt->cl_principal);
+		p += len;
+		gss_msg->msg.len += len;
+	}
+	if (machine_cred) {
+		len = sprintf(p, "service=* ");
+		p += len;
+		gss_msg->msg.len += len;
+	} else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
+		len = sprintf(p, "service=nfs ");
+		p += len;
+		gss_msg->msg.len += len;
+	}
+	len = sprintf(p, "\n");
+	gss_msg->msg.len += len;
+
+	gss_msg->msg.data = gss_msg->databuf;
+	BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
+}
+
+static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
+				struct rpc_clnt *clnt, int machine_cred)
+{
+	if (pipe_version == 0)
+		gss_encode_v0_msg(gss_msg);
+	else /* pipe_version == 1 */
+		gss_encode_v1_msg(gss_msg, clnt, machine_cred);
+}
+
 static inline struct gss_upcall_msg *
-gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
+gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
+		int machine_cred)
 {
 	struct gss_upcall_msg *gss_msg;
+	int vers;
 
 	gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
-	if (gss_msg != NULL) {
-		INIT_LIST_HEAD(&gss_msg->list);
-		rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
-		init_waitqueue_head(&gss_msg->waitqueue);
-		atomic_set(&gss_msg->count, 1);
-		gss_msg->msg.data = &gss_msg->uid;
-		gss_msg->msg.len = sizeof(gss_msg->uid);
-		gss_msg->uid = uid;
-		gss_msg->auth = gss_auth;
+	if (gss_msg == NULL)
+		return ERR_PTR(-ENOMEM);
+	vers = get_pipe_version();
+	if (vers < 0) {
+		kfree(gss_msg);
+		return ERR_PTR(vers);
 	}
+	gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
+	INIT_LIST_HEAD(&gss_msg->list);
+	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
+	init_waitqueue_head(&gss_msg->waitqueue);
+	atomic_set(&gss_msg->count, 1);
+	gss_msg->uid = uid;
+	gss_msg->auth = gss_auth;
+	gss_encode_msg(gss_msg, clnt, machine_cred);
 	return gss_msg;
 }
 
@@ -350,16 +442,13 @@ gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cr
 	struct gss_upcall_msg *gss_new, *gss_msg;
 	uid_t uid = cred->cr_uid;
 
-	/* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
-	if (gss_cred->gc_machine_cred != 0)
-		uid = 0;
-
-	gss_new = gss_alloc_msg(gss_auth, uid);
-	if (gss_new == NULL)
-		return ERR_PTR(-ENOMEM);
+	gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
+	if (IS_ERR(gss_new))
+		return gss_new;
 	gss_msg = gss_add_msg(gss_auth, gss_new);
 	if (gss_msg == gss_new) {
-		int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
+		struct inode *inode = &gss_new->inode->vfs_inode;
+		int res = rpc_queue_upcall(inode, &gss_new->msg);
 		if (res) {
 			gss_unhash_msg(gss_new);
 			gss_msg = ERR_PTR(res);
@@ -369,6 +458,18 @@ gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cr
 	return gss_msg;
 }
 
+static void warn_gssd(void)
+{
+	static unsigned long ratelimit;
+	unsigned long now = jiffies;
+
+	if (time_after(now, ratelimit)) {
+		printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
+				"Please check user daemon is running.\n");
+		ratelimit = now + 15*HZ;
+	}
+}
+
 static inline int
 gss_refresh_upcall(struct rpc_task *task)
 {
@@ -378,16 +479,25 @@ gss_refresh_upcall(struct rpc_task *task)
 	struct gss_cred *gss_cred = container_of(cred,
 			struct gss_cred, gc_base);
 	struct gss_upcall_msg *gss_msg;
-	struct inode *inode = gss_auth->dentry->d_inode;
+	struct inode *inode;
 	int err = 0;
 
 	dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 								cred->cr_uid);
 	gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
+	if (IS_ERR(gss_msg) == -EAGAIN) {
+		/* XXX: warning on the first, under the assumption we
+		 * shouldn't normally hit this case on a refresh. */
+		warn_gssd();
+		task->tk_timeout = 15*HZ;
+		rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
+		return 0;
+	}
 	if (IS_ERR(gss_msg)) {
 		err = PTR_ERR(gss_msg);
 		goto out;
 	}
+	inode = &gss_msg->inode->vfs_inode;
 	spin_lock(&inode->i_lock);
 	if (gss_cred->gc_upcall != NULL)
 		rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
@@ -414,18 +524,29 @@ out:
 static inline int
 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 {
-	struct inode *inode = gss_auth->dentry->d_inode;
+	struct inode *inode;
 	struct rpc_cred *cred = &gss_cred->gc_base;
 	struct gss_upcall_msg *gss_msg;
 	DEFINE_WAIT(wait);
 	int err = 0;
 
 	dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
+retry:
 	gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
+	if (PTR_ERR(gss_msg) == -EAGAIN) {
+		err = wait_event_interruptible_timeout(pipe_version_waitqueue,
+				pipe_version >= 0, 15*HZ);
+		if (err)
+			goto out;
+		if (pipe_version < 0)
+			warn_gssd();
+		goto retry;
+	}
 	if (IS_ERR(gss_msg)) {
 		err = PTR_ERR(gss_msg);
 		goto out;
 	}
+	inode = &gss_msg->inode->vfs_inode;
 	for (;;) {
 		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 		spin_lock(&inode->i_lock);
@@ -543,6 +664,38 @@ out:
 	return err;
 }
 
+static int gss_pipe_open(struct inode *inode, int new_version)
+{
+	int ret = 0;
+
+	spin_lock(&pipe_version_lock);
+	if (pipe_version < 0) {
+		/* First open of any gss pipe determines the version: */
+		pipe_version = new_version;
+		rpc_wake_up(&pipe_version_rpc_waitqueue);
+		wake_up(&pipe_version_waitqueue);
+	} else if (pipe_version != new_version) {
+		/* Trying to open a pipe of a different version */
+		ret = -EBUSY;
+		goto out;
+	}
+	atomic_inc(&pipe_users);
+out:
+	spin_unlock(&pipe_version_lock);
+	return ret;
+
+}
+
+static int gss_pipe_open_v0(struct inode *inode)
+{
+	return gss_pipe_open(inode, 0);
+}
+
+static int gss_pipe_open_v1(struct inode *inode)
+{
+	return gss_pipe_open(inode, 1);
+}
+
 static void
 gss_pipe_release(struct inode *inode)
 {
@@ -562,27 +715,22 @@ gss_pipe_release(struct inode *inode)
 		spin_lock(&inode->i_lock);
 	}
 	spin_unlock(&inode->i_lock);
+
+	put_pipe_version();
 }
 
 static void
 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 {
 	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
-	static unsigned long ratelimit;
 
 	if (msg->errno < 0) {
 		dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 				gss_msg);
 		atomic_inc(&gss_msg->count);
 		gss_unhash_msg(gss_msg);
-		if (msg->errno == -ETIMEDOUT) {
-			unsigned long now = jiffies;
-			if (time_after(now, ratelimit)) {
-				printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
-						    "Please check user daemon is running!\n");
-				ratelimit = now + 15*HZ;
-			}
-		}
+		if (msg->errno == -ETIMEDOUT)
+			warn_gssd();
 		gss_release_msg(gss_msg);
 	}
 }
@@ -623,20 +771,38 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 	atomic_set(&auth->au_count, 1);
 	kref_init(&gss_auth->kref);
 
-	gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
-			clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
-	if (IS_ERR(gss_auth->dentry)) {
-		err = PTR_ERR(gss_auth->dentry);
+	/*
+	 * Note: if we created the old pipe first, then someone who
+	 * examined the directory at the right moment might conclude
+	 * that we supported only the old pipe.  So we instead create
+	 * the new pipe first.
+	 */
+	gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_dentry,
+					 "gssd",
+					 clnt, &gss_upcall_ops_v1,
+					 RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(gss_auth->dentry[1])) {
+		err = PTR_ERR(gss_auth->dentry[1]);
 		goto err_put_mech;
 	}
 
+	gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_dentry,
+					 gss_auth->mech->gm_name,
+					 clnt, &gss_upcall_ops_v0,
+					 RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(gss_auth->dentry[0])) {
+		err = PTR_ERR(gss_auth->dentry[0]);
+		goto err_unlink_pipe_1;
+	}
 	err = rpcauth_init_credcache(auth);
 	if (err)
-		goto err_unlink_pipe;
+		goto err_unlink_pipe_0;
 
 	return auth;
-err_unlink_pipe:
-	rpc_unlink(gss_auth->dentry);
+err_unlink_pipe_0:
+	rpc_unlink(gss_auth->dentry[0]);
+err_unlink_pipe_1:
+	rpc_unlink(gss_auth->dentry[1]);
 err_put_mech:
 	gss_mech_put(gss_auth->mech);
 err_free:
@@ -649,8 +815,8 @@ out_dec:
 static void
 gss_free(struct gss_auth *gss_auth)
 {
-	rpc_unlink(gss_auth->dentry);
-	gss_auth->dentry = NULL;
+	rpc_unlink(gss_auth->dentry[1]);
+	rpc_unlink(gss_auth->dentry[0]);
 	gss_mech_put(gss_auth->mech);
 
 	kfree(gss_auth);
@@ -693,7 +859,7 @@ gss_destroying_context(struct rpc_cred *cred)
 	struct rpc_task *task;
 
 	if (gss_cred->gc_ctx == NULL ||
-	    test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
+	    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 		return 0;
 
 	gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
@@ -757,14 +923,12 @@ gss_free_cred_callback(struct rcu_head *head)
 }
 
 static void
-gss_destroy_cred(struct rpc_cred *cred)
+gss_destroy_nullcred(struct rpc_cred *cred)
 {
 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 
-	if (gss_destroying_context(cred))
-		return;
 	rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 	if (ctx)
@@ -772,6 +936,15 @@ gss_destroy_cred(struct rpc_cred *cred)
 	kref_put(&gss_auth->kref, gss_free_callback);
 }
 
+static void
+gss_destroy_cred(struct rpc_cred *cred)
+{
+
+	if (gss_destroying_context(cred))
+		return;
+	gss_destroy_nullcred(cred);
+}
+
 /*
  * Lookup RPCSEC_GSS cred for the current process
  */
@@ -1017,7 +1190,7 @@ gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 	*p++ = htonl(rqstp->rq_seqno);
 
-	status = rpc_call_xdrproc(encode, rqstp, p, obj);
+	status = encode(rqstp, p, obj);
 	if (status)
 		return status;
 
@@ -1111,7 +1284,7 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 	*p++ = htonl(rqstp->rq_seqno);
 
-	status = rpc_call_xdrproc(encode, rqstp, p, obj);
+	status = encode(rqstp, p, obj);
 	if (status)
 		return status;
 
@@ -1170,12 +1343,12 @@ gss_wrap_req(struct rpc_task *task,
 		/* The spec seems a little ambiguous here, but I think that not
 		 * wrapping context destruction requests makes the most sense.
 		 */
-		status = rpc_call_xdrproc(encode, rqstp, p, obj);
+		status = encode(rqstp, p, obj);
 		goto out;
 	}
 	switch (gss_cred->gc_service) {
 		case RPC_GSS_SVC_NONE:
-			status = rpc_call_xdrproc(encode, rqstp, p, obj);
+			status = encode(rqstp, p, obj);
 			break;
 		case RPC_GSS_SVC_INTEGRITY:
 			status = gss_wrap_req_integ(cred, ctx, encode,
@@ -1291,7 +1464,7 @@ gss_unwrap_resp(struct rpc_task *task,
 	cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
 						+ (savedlen - head->iov_len);
 out_decode:
-	status = rpc_call_xdrproc(decode, rqstp, p, obj);
+	status = decode(rqstp, p, obj);
 out:
 	gss_put_ctx(ctx);
 	dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
@@ -1324,7 +1497,7 @@ static const struct rpc_credops gss_credops = {
 
 static const struct rpc_credops gss_nullops = {
 	.cr_name	= "AUTH_GSS",
-	.crdestroy	= gss_destroy_cred,
+	.crdestroy	= gss_destroy_nullcred,
 	.crbind		= rpcauth_generic_bind_cred,
 	.crmatch	= gss_match,
 	.crmarshal	= gss_marshal,
@@ -1334,10 +1507,19 @@ static const struct rpc_credops gss_nullops = {
 	.crunwrap_resp	= gss_unwrap_resp,
 };
 
-static struct rpc_pipe_ops gss_upcall_ops = {
+static struct rpc_pipe_ops gss_upcall_ops_v0 = {
+	.upcall		= gss_pipe_upcall,
+	.downcall	= gss_pipe_downcall,
+	.destroy_msg	= gss_pipe_destroy_msg,
+	.open_pipe	= gss_pipe_open_v0,
+	.release_pipe	= gss_pipe_release,
+};
+
+static struct rpc_pipe_ops gss_upcall_ops_v1 = {
 	.upcall		= gss_pipe_upcall,
 	.downcall	= gss_pipe_downcall,
 	.destroy_msg	= gss_pipe_destroy_msg,
+	.open_pipe	= gss_pipe_open_v1,
 	.release_pipe	= gss_pipe_release,
 };
 
@@ -1354,6 +1536,7 @@ static int __init init_rpcsec_gss(void)
 	err = gss_svc_init();
 	if (err)
 		goto out_unregister;
+	rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
 	return 0;
 out_unregister:
 	rpcauth_unregister(&authgss_ops);