[CRYPTO] api: Add async blkcipher type

This patch adds the mid-level interface for asynchronous block ciphers.
It also includes a generic queueing mechanism that can be used by other
asynchronous crypto operations in future.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/Kconfig

@@ -16,6 +16,10 @@ config CRYPTO_ALGAPI
 	help
 	  This option provides the API for cryptographic algorithms.
 
+config CRYPTO_ABLKCIPHER
+	tristate
+	select CRYPTO_BLKCIPHER
+
 config CRYPTO_BLKCIPHER
 	tristate
 	select CRYPTO_ALGAPI

crypto/Makefile

@@ -8,6 +8,7 @@ crypto_algapi-$(CONFIG_PROC_FS) += proc.o
 crypto_algapi-objs := algapi.o $(crypto_algapi-y)
 obj-$(CONFIG_CRYPTO_ALGAPI) += crypto_algapi.o
 
+obj-$(CONFIG_CRYPTO_ABLKCIPHER) += ablkcipher.o
 obj-$(CONFIG_CRYPTO_BLKCIPHER) += blkcipher.o
 
 crypto_hash-objs := hash.o

crypto/ablkcipher.c

@@ -0,0 +1,83 @@
+/*
+ * Asynchronous block chaining cipher operations.
+ * 
+ * This is the asynchronous version of blkcipher.c indicating completion
+ * via a callback.
+ *
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option) 
+ * any later version.
+ *
+ */
+
+#include <crypto/algapi.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+
+static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+		  unsigned int keylen)
+{
+	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
+
+	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
+		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	return cipher->setkey(tfm, key, keylen);
+}
+
+static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
+					      u32 mask)
+{
+	return alg->cra_ctxsize;
+}
+
+static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
+				      u32 mask)
+{
+	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
+	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
+
+	if (alg->ivsize > PAGE_SIZE / 8)
+		return -EINVAL;
+
+	crt->setkey = setkey;
+	crt->encrypt = alg->encrypt;
+	crt->decrypt = alg->decrypt;
+	crt->ivsize = alg->ivsize;
+
+	return 0;
+}
+
+static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
+	__attribute__ ((unused));
+static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
+
+	seq_printf(m, "type         : ablkcipher\n");
+	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
+	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
+	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
+	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
+	seq_printf(m, "qlen         : %u\n", ablkcipher->queue->qlen);
+	seq_printf(m, "max qlen     : %u\n", ablkcipher->queue->max_qlen);
+}
+
+const struct crypto_type crypto_ablkcipher_type = {
+	.ctxsize = crypto_ablkcipher_ctxsize,
+	.init = crypto_init_ablkcipher_ops,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_ablkcipher_show,
+#endif
+};
+EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Asynchronous block chaining cipher type");

crypto/algapi.c

@@ -507,6 +507,68 @@ err_free_inst:
 }
 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
 
+void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
+{
+	INIT_LIST_HEAD(&queue->list);
+	queue->backlog = &queue->list;
+	queue->qlen = 0;
+	queue->max_qlen = max_qlen;
+}
+EXPORT_SYMBOL_GPL(crypto_init_queue);
+
+int crypto_enqueue_request(struct crypto_queue *queue,
+			   struct crypto_async_request *request)
+{
+	int err = -EINPROGRESS;
+
+	if (unlikely(queue->qlen >= queue->max_qlen)) {
+		err = -EBUSY;
+		if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
+			goto out;
+		if (queue->backlog == &queue->list)
+			queue->backlog = &request->list;
+	}
+
+	queue->qlen++;
+	list_add_tail(&request->list, &queue->list);
+
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(crypto_enqueue_request);
+
+struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
+{
+	struct list_head *request;
+
+	if (unlikely(!queue->qlen))
+		return NULL;
+
+	queue->qlen--;
+
+	if (queue->backlog != &queue->list)
+		queue->backlog = queue->backlog->next;
+
+	request = queue->list.next;
+	list_del(request);
+
+	return list_entry(request, struct crypto_async_request, list);
+}
+EXPORT_SYMBOL_GPL(crypto_dequeue_request);
+
+int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
+{
+	struct crypto_async_request *req;
+
+	list_for_each_entry(req, &queue->list, list) {
+		if (req->tfm == tfm)
+			return 1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
+
 static int __init crypto_algapi_init(void)
 {
 	crypto_init_proc();