libceph: Create a new key type "ceph".

This allows us to use existence of the key type as a feature test,
from userspace.
Signed-off-by: Tommi Virtanen <tommi.virtanen@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>

include/keys/ceph-type.h

+#ifndef _KEYS_CEPH_TYPE_H
+#define _KEYS_CEPH_TYPE_H
+
+#include <linux/key.h>
+
+extern struct key_type key_type_ceph;
+
+#endif

net/ceph/ceph_common.c

@@ -6,7 +6,7 @@
 #include <linux/inet.h>
 #include <linux/in6.h>
 #include <linux/key.h>
-#include <keys/user-type.h>
+#include <keys/ceph-type.h>
 #include <linux/module.h>
 #include <linux/mount.h>
 #include <linux/parser.h>
@@ -241,10 +241,9 @@ static int get_secret(struct ceph_crypto_key *dst, const char *name) {
 	struct key *ukey;
 	int key_err;
 	int err = 0;
-	struct user_key_payload *payload;
-	void *p;
+	struct ceph_crypto_key *ckey;
 
-	ukey = request_key(&key_type_user, name, NULL);
+	ukey = request_key(&key_type_ceph, name, NULL);
 	if (!ukey || IS_ERR(ukey)) {
 		/* request_key errors don't map nicely to mount(2)
 		   errors; don't even try, but still printk */
@@ -267,9 +266,8 @@ static int get_secret(struct ceph_crypto_key *dst, const char *name) {
 		goto out;
 	}
 
-	payload = ukey->payload.data;
-	p = payload->data;
-	err = ceph_crypto_key_decode(dst, &p, p + payload->datalen);
+	ckey = ukey->payload.data;
+	err = ceph_crypto_key_clone(dst, ckey);
 	if (err)
 		goto out_key;
 	/* pass through, err is 0 */
@@ -583,10 +581,14 @@ static int __init init_ceph_lib(void)
 	if (ret < 0)
 		goto out;
 
-	ret = ceph_msgr_init();
+	ret = ceph_crypto_init();
 	if (ret < 0)
 		goto out_debugfs;
 
+	ret = ceph_msgr_init();
+	if (ret < 0)
+		goto out_crypto;
+
 	pr_info("loaded (mon/osd proto %d/%d, osdmap %d/%d %d/%d)\n",
 		CEPH_MONC_PROTOCOL, CEPH_OSDC_PROTOCOL,
 		CEPH_OSDMAP_VERSION, CEPH_OSDMAP_VERSION_EXT,
@@ -594,6 +596,8 @@ static int __init init_ceph_lib(void)
 
 	return 0;
 
+out_crypto:
+	ceph_crypto_shutdown();
 out_debugfs:
 	ceph_debugfs_cleanup();
 out:
@@ -604,6 +608,7 @@ static void __exit exit_ceph_lib(void)
 {
 	dout("exit_ceph_lib\n");
 	ceph_msgr_exit();
+	ceph_crypto_shutdown();
 	ceph_debugfs_cleanup();
 }
 

net/ceph/crypto.c

@@ -5,7 +5,9 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <crypto/hash.h>
+#include <linux/key-type.h>
 
+#include <keys/ceph-type.h>
 #include <linux/ceph/decode.h>
 #include "crypto.h"
 
@@ -421,3 +423,63 @@ int ceph_encrypt2(struct ceph_crypto_key *secret, void *dst, size_t *dst_len,
 		return -EINVAL;
 	}
 }
+
+int ceph_key_instantiate(struct key *key, const void *data, size_t datalen)
+{
+	struct ceph_crypto_key *ckey;
+	int ret;
+	void *p;
+
+	ret = -EINVAL;
+	if (datalen <= 0 || datalen > 32767 || !data)
+		goto err;
+
+	ret = key_payload_reserve(key, datalen);
+	if (ret < 0)
+		goto err;
+
+	ret = -ENOMEM;
+	ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
+	if (!ckey)
+		goto err;
+
+	/* TODO ceph_crypto_key_decode should really take const input */
+	p = (void*)data;
+	ret = ceph_crypto_key_decode(ckey, &p, (char*)data+datalen);
+	if (ret < 0)
+		goto err_ckey;
+
+	key->payload.data = ckey;
+	return 0;
+
+err_ckey:
+	kfree(ckey);
+err:
+	return ret;
+}
+
+int ceph_key_match(const struct key *key, const void *description)
+{
+	return strcmp(key->description, description) == 0;
+}
+
+void ceph_key_destroy(struct key *key) {
+	struct ceph_crypto_key *ckey = key->payload.data;
+
+	ceph_crypto_key_destroy(ckey);
+}
+
+struct key_type key_type_ceph = {
+	.name		= "ceph",
+	.instantiate	= ceph_key_instantiate,
+	.match		= ceph_key_match,
+	.destroy	= ceph_key_destroy,
+};
+
+int ceph_crypto_init(void) {
+	return register_key_type(&key_type_ceph);
+}
+
+void ceph_crypto_shutdown(void) {
+	unregister_key_type(&key_type_ceph);
+}

net/ceph/crypto.h

@@ -42,6 +42,8 @@ extern int ceph_encrypt2(struct ceph_crypto_key *secret,
 			 void *dst, size_t *dst_len,
 			 const void *src1, size_t src1_len,
 			 const void *src2, size_t src2_len);
+extern int ceph_crypto_init(void);
+extern void ceph_crypto_shutdown(void);
 
 /* armor.c */
 extern int ceph_armor(char *dst, const char *src, const char *end);