1 files changed, 254 insertions, 0 deletions
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
new file mode 100644
index 000000000..185e56d4f
--- /dev/null
+++ b/net/sunrpc/auth_unix.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/net/sunrpc/auth_unix.c
+ *
+ * UNIX-style authentication; no AUTH_SHORT support
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/user_namespace.h>
+
+struct unx_cred {
+	struct rpc_cred		uc_base;
+	kgid_t			uc_gid;
+	kgid_t			uc_gids[UNX_NGROUPS];
+};
+#define uc_uid			uc_base.cr_uid
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+static struct rpc_auth		unix_auth;
+static const struct rpc_credops	unix_credops;
+
+static struct rpc_auth *
+unx_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+	dprintk("RPC:       creating UNIX authenticator for client %p\n",
+			clnt);
+	atomic_inc(&unix_auth.au_count);
+	return &unix_auth;
+}
+
+static void
+unx_destroy(struct rpc_auth *auth)
+{
+	dprintk("RPC:       destroying UNIX authenticator %p\n", auth);
+	rpcauth_clear_credcache(auth->au_credcache);
+}
+
+static int
+unx_hash_cred(struct auth_cred *acred, unsigned int hashbits)
+{
+	return hash_64(from_kgid(&init_user_ns, acred->gid) |
+		((u64)from_kuid(&init_user_ns, acred->uid) <<
+			(sizeof(gid_t) * 8)), hashbits);
+}
+
+/*
+ * Lookup AUTH_UNIX creds for current process
+ */
+static struct rpc_cred *
+unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+	return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
+}
+
+static struct rpc_cred *
+unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
+{
+	struct unx_cred	*cred;
+	unsigned int groups = 0;
+	unsigned int i;
+
+	dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
+			from_kuid(&init_user_ns, acred->uid),
+			from_kgid(&init_user_ns, acred->gid));
+
+	if (!(cred = kmalloc(sizeof(*cred), gfp)))
+		return ERR_PTR(-ENOMEM);
+
+	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
+	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
+
+	if (acred->group_info != NULL)
+		groups = acred->group_info->ngroups;
+	if (groups > UNX_NGROUPS)
+		groups = UNX_NGROUPS;
+
+	cred->uc_gid = acred->gid;
+	for (i = 0; i < groups; i++)
+		cred->uc_gids[i] = acred->group_info->gid[i];
+	if (i < UNX_NGROUPS)
+		cred->uc_gids[i] = INVALID_GID;
+
+	return &cred->uc_base;
+}
+
+static void
+unx_free_cred(struct unx_cred *unx_cred)
+{
+	dprintk("RPC:       unx_free_cred %p\n", unx_cred);
+	kfree(unx_cred);
+}
+
+static void
+unx_free_cred_callback(struct rcu_head *head)
+{
+	struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
+	unx_free_cred(unx_cred);
+}
+
+static void
+unx_destroy_cred(struct rpc_cred *cred)
+{
+	call_rcu(&cred->cr_rcu, unx_free_cred_callback);
+}
+
+/*
+ * Match credentials against current process creds.
+ * The root_override argument takes care of cases where the caller may
+ * request root creds (e.g. for NFS swapping).
+ */
+static int
+unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
+{
+	struct unx_cred	*cred = container_of(rcred, struct unx_cred, uc_base);
+	unsigned int groups = 0;
+	unsigned int i;
+
+
+	if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
+		return 0;
+
+	if (acred->group_info != NULL)
+		groups = acred->group_info->ngroups;
+	if (groups > UNX_NGROUPS)
+		groups = UNX_NGROUPS;
+	for (i = 0; i < groups ; i++)
+		if (!gid_eq(cred->uc_gids[i], acred->group_info->gid[i]))
+			return 0;
+	if (groups < UNX_NGROUPS && gid_valid(cred->uc_gids[groups]))
+		return 0;
+	return 1;
+}
+
+/*
+ * Marshal credentials.
+ * Maybe we should keep a cached credential for performance reasons.
+ */
+static __be32 *
+unx_marshal(struct rpc_task *task, __be32 *p)
+{
+	struct rpc_clnt	*clnt = task->tk_client;
+	struct unx_cred	*cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
+	__be32		*base, *hold;
+	int		i;
+
+	*p++ = htonl(RPC_AUTH_UNIX);
+	base = p++;
+	*p++ = htonl(jiffies/HZ);
+
+	/*
+	 * Copy the UTS nodename captured when the client was created.
+	 */
+	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
+
+	*p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
+	*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
+	hold = p++;
+	for (i = 0; i < UNX_NGROUPS && gid_valid(cred->uc_gids[i]); i++)
+		*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
+	*hold = htonl(p - hold - 1);		/* gid array length */
+	*base = htonl((p - base - 1) << 2);	/* cred length */
+
+	*p++ = htonl(RPC_AUTH_NULL);
+	*p++ = htonl(0);
+
+	return p;
+}
+
+/*
+ * Refresh credentials. This is a no-op for AUTH_UNIX
+ */
+static int
+unx_refresh(struct rpc_task *task)
+{
+	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
+	return 0;
+}
+
+static __be32 *
+unx_validate(struct rpc_task *task, __be32 *p)
+{
+	rpc_authflavor_t	flavor;
+	u32			size;
+
+	flavor = ntohl(*p++);
+	if (flavor != RPC_AUTH_NULL &&
+	    flavor != RPC_AUTH_UNIX &&
+	    flavor != RPC_AUTH_SHORT) {
+		printk("RPC: bad verf flavor: %u\n", flavor);
+		return ERR_PTR(-EIO);
+	}
+
+	size = ntohl(*p++);
+	if (size > RPC_MAX_AUTH_SIZE) {
+		printk("RPC: giant verf size: %u\n", size);
+		return ERR_PTR(-EIO);
+	}
+	task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
+	p += (size >> 2);
+
+	return p;
+}
+
+int __init rpc_init_authunix(void)
+{
+	return rpcauth_init_credcache(&unix_auth);
+}
+
+void rpc_destroy_authunix(void)
+{
+	rpcauth_destroy_credcache(&unix_auth);
+}
+
+const struct rpc_authops authunix_ops = {
+	.owner		= THIS_MODULE,
+	.au_flavor	= RPC_AUTH_UNIX,
+	.au_name	= "UNIX",
+	.create		= unx_create,
+	.destroy	= unx_destroy,
+	.hash_cred	= unx_hash_cred,
+	.lookup_cred	= unx_lookup_cred,
+	.crcreate	= unx_create_cred,
+};
+
+static
+struct rpc_auth		unix_auth = {
+	.au_cslack	= UNX_CALLSLACK,
+	.au_rslack	= NUL_REPLYSLACK,
+	.au_flags	= RPCAUTH_AUTH_NO_CRKEY_TIMEOUT,
+	.au_ops		= &authunix_ops,
+	.au_flavor	= RPC_AUTH_UNIX,
+	.au_count	= ATOMIC_INIT(0),
+};
+
+static
+const struct rpc_credops unix_credops = {
+	.cr_name	= "AUTH_UNIX",
+	.crdestroy	= unx_destroy_cred,
+	.crbind		= rpcauth_generic_bind_cred,
+	.crmatch	= unx_match,
+	.crmarshal	= unx_marshal,
+	.crrefresh	= unx_refresh,
+	.crvalidate	= unx_validate,
+};