Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1211 insertions, 0 deletions

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
new file mode 100644
index 000000000..d0276a4ed
--- /dev/null
+++ b/crypto/af_alg.c
@@ -0,0 +1,1211 @@
+/*
+ * af_alg: User-space algorithm interface
+ *
+ * This file provides the user-space API for algorithms.
+ *
+ * Copyright (c) 2010 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 <linux/atomic.h>
+#include <crypto/if_alg.h>
+#include <linux/crypto.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/rwsem.h>
+#include <linux/sched/signal.h>
+#include <linux/security.h>
+
+struct alg_type_list {
+	const struct af_alg_type *type;
+	struct list_head list;
+};
+
+static atomic_long_t alg_memory_allocated;
+
+static struct proto alg_proto = {
+	.name			= "ALG",
+	.owner			= THIS_MODULE,
+	.memory_allocated	= &alg_memory_allocated,
+	.obj_size		= sizeof(struct alg_sock),
+};
+
+static LIST_HEAD(alg_types);
+static DECLARE_RWSEM(alg_types_sem);
+
+static const struct af_alg_type *alg_get_type(const char *name)
+{
+	const struct af_alg_type *type = ERR_PTR(-ENOENT);
+	struct alg_type_list *node;
+
+	down_read(&alg_types_sem);
+	list_for_each_entry(node, &alg_types, list) {
+		if (strcmp(node->type->name, name))
+			continue;
+
+		if (try_module_get(node->type->owner))
+			type = node->type;
+		break;
+	}
+	up_read(&alg_types_sem);
+
+	return type;
+}
+
+int af_alg_register_type(const struct af_alg_type *type)
+{
+	struct alg_type_list *node;
+	int err = -EEXIST;
+
+	down_write(&alg_types_sem);
+	list_for_each_entry(node, &alg_types, list) {
+		if (!strcmp(node->type->name, type->name))
+			goto unlock;
+	}
+
+	node = kmalloc(sizeof(*node), GFP_KERNEL);
+	err = -ENOMEM;
+	if (!node)
+		goto unlock;
+
+	type->ops->owner = THIS_MODULE;
+	if (type->ops_nokey)
+		type->ops_nokey->owner = THIS_MODULE;
+	node->type = type;
+	list_add(&node->list, &alg_types);
+	err = 0;
+
+unlock:
+	up_write(&alg_types_sem);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(af_alg_register_type);
+
+int af_alg_unregister_type(const struct af_alg_type *type)
+{
+	struct alg_type_list *node;
+	int err = -ENOENT;
+
+	down_write(&alg_types_sem);
+	list_for_each_entry(node, &alg_types, list) {
+		if (strcmp(node->type->name, type->name))
+			continue;
+
+		list_del(&node->list);
+		kfree(node);
+		err = 0;
+		break;
+	}
+	up_write(&alg_types_sem);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(af_alg_unregister_type);
+
+static void alg_do_release(const struct af_alg_type *type, void *private)
+{
+	if (!type)
+		return;
+
+	type->release(private);
+	module_put(type->owner);
+}
+
+int af_alg_release(struct socket *sock)
+{
+	if (sock->sk) {
+		sock_put(sock->sk);
+		sock->sk = NULL;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(af_alg_release);
+
+void af_alg_release_parent(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	unsigned int nokey = atomic_read(&ask->nokey_refcnt);
+
+	sk = ask->parent;
+	ask = alg_sk(sk);
+
+	if (nokey)
+		atomic_dec(&ask->nokey_refcnt);
+
+	if (atomic_dec_and_test(&ask->refcnt))
+		sock_put(sk);
+}
+EXPORT_SYMBOL_GPL(af_alg_release_parent);
+
+static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+{
+	const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct sockaddr_alg_new *sa = (void *)uaddr;
+	const struct af_alg_type *type;
+	void *private;
+	int err;
+
+	if (sock->state == SS_CONNECTED)
+		return -EINVAL;
+
+	BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) !=
+		     offsetof(struct sockaddr_alg, salg_name));
+	BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa));
+
+	if (addr_len < sizeof(*sa) + 1)
+		return -EINVAL;
+
+	/* If caller uses non-allowed flag, return error. */
+	if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
+		return -EINVAL;
+
+	sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
+	sa->salg_name[addr_len - sizeof(*sa) - 1] = 0;
+
+	type = alg_get_type(sa->salg_type);
+	if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
+		request_module("algif-%s", sa->salg_type);
+		type = alg_get_type(sa->salg_type);
+	}
+
+	if (IS_ERR(type))
+		return PTR_ERR(type);
+
+	private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
+	if (IS_ERR(private)) {
+		module_put(type->owner);
+		return PTR_ERR(private);
+	}
+
+	err = -EBUSY;
+	lock_sock(sk);
+	if (atomic_read(&ask->refcnt))
+		goto unlock;
+
+	swap(ask->type, type);
+	swap(ask->private, private);
+
+	err = 0;
+
+unlock:
+	release_sock(sk);
+
+	alg_do_release(type, private);
+
+	return err;
+}
+
+static int alg_setkey(struct sock *sk, char __user *ukey,
+		      unsigned int keylen)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	const struct af_alg_type *type = ask->type;
+	u8 *key;
+	int err;
+
+	key = sock_kmalloc(sk, keylen, GFP_KERNEL);
+	if (!key)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	if (copy_from_user(key, ukey, keylen))
+		goto out;
+
+	err = type->setkey(ask->private, key, keylen);
+
+out:
+	sock_kzfree_s(sk, key, keylen);
+
+	return err;
+}
+
+static int alg_setsockopt(struct socket *sock, int level, int optname,
+			  char __user *optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	const struct af_alg_type *type;
+	int err = -EBUSY;
+
+	lock_sock(sk);
+	if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
+		goto unlock;
+
+	type = ask->type;
+
+	err = -ENOPROTOOPT;
+	if (level != SOL_ALG || !type)
+		goto unlock;
+
+	switch (optname) {
+	case ALG_SET_KEY:
+		if (sock->state == SS_CONNECTED)
+			goto unlock;
+		if (!type->setkey)
+			goto unlock;
+
+		err = alg_setkey(sk, optval, optlen);
+		break;
+	case ALG_SET_AEAD_AUTHSIZE:
+		if (sock->state == SS_CONNECTED)
+			goto unlock;
+		if (!type->setauthsize)
+			goto unlock;
+		err = type->setauthsize(ask->private, optlen);
+	}
+
+unlock:
+	release_sock(sk);
+
+	return err;
+}
+
+int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	const struct af_alg_type *type;
+	struct sock *sk2;
+	unsigned int nokey;
+	int err;
+
+	lock_sock(sk);
+	type = ask->type;
+
+	err = -EINVAL;
+	if (!type)
+		goto unlock;
+
+	sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
+	err = -ENOMEM;
+	if (!sk2)
+		goto unlock;
+
+	sock_init_data(newsock, sk2);
+	security_sock_graft(sk2, newsock);
+	security_sk_clone(sk, sk2);
+
+	err = type->accept(ask->private, sk2);
+
+	nokey = err == -ENOKEY;
+	if (nokey && type->accept_nokey)
+		err = type->accept_nokey(ask->private, sk2);
+
+	if (err)
+		goto unlock;
+
+	sk2->sk_family = PF_ALG;
+
+	if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
+		sock_hold(sk);
+	if (nokey) {
+		atomic_inc(&ask->nokey_refcnt);
+		atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
+	}
+	alg_sk(sk2)->parent = sk;
+	alg_sk(sk2)->type = type;
+
+	newsock->ops = type->ops;
+	newsock->state = SS_CONNECTED;
+
+	if (nokey)
+		newsock->ops = type->ops_nokey;
+
+	err = 0;
+
+unlock:
+	release_sock(sk);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(af_alg_accept);
+
+static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
+		      bool kern)
+{
+	return af_alg_accept(sock->sk, newsock, kern);
+}
+
+static const struct proto_ops alg_proto_ops = {
+	.family		=	PF_ALG,
+	.owner		=	THIS_MODULE,
+
+	.connect	=	sock_no_connect,
+	.socketpair	=	sock_no_socketpair,
+	.getname	=	sock_no_getname,
+	.ioctl		=	sock_no_ioctl,
+	.listen		=	sock_no_listen,
+	.shutdown	=	sock_no_shutdown,
+	.getsockopt	=	sock_no_getsockopt,
+	.mmap		=	sock_no_mmap,
+	.sendpage	=	sock_no_sendpage,
+	.sendmsg	=	sock_no_sendmsg,
+	.recvmsg	=	sock_no_recvmsg,
+
+	.bind		=	alg_bind,
+	.release	=	af_alg_release,
+	.setsockopt	=	alg_setsockopt,
+	.accept		=	alg_accept,
+};
+
+static void alg_sock_destruct(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+
+	alg_do_release(ask->type, ask->private);
+}
+
+static int alg_create(struct net *net, struct socket *sock, int protocol,
+		      int kern)
+{
+	struct sock *sk;
+	int err;
+
+	if (sock->type != SOCK_SEQPACKET)
+		return -ESOCKTNOSUPPORT;
+	if (protocol != 0)
+		return -EPROTONOSUPPORT;
+
+	err = -ENOMEM;
+	sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
+	if (!sk)
+		goto out;
+
+	sock->ops = &alg_proto_ops;
+	sock_init_data(sock, sk);
+
+	sk->sk_family = PF_ALG;
+	sk->sk_destruct = alg_sock_destruct;
+
+	return 0;
+out:
+	return err;
+}
+
+static const struct net_proto_family alg_family = {
+	.family	=	PF_ALG,
+	.create	=	alg_create,
+	.owner	=	THIS_MODULE,
+};
+
+int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
+{
+	size_t off;
+	ssize_t n;
+	int npages, i;
+
+	n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
+	if (n < 0)
+		return n;
+
+	npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	if (WARN_ON(npages == 0))
+		return -EINVAL;
+	/* Add one extra for linking */
+	sg_init_table(sgl->sg, npages + 1);
+
+	for (i = 0, len = n; i < npages; i++) {
+		int plen = min_t(int, len, PAGE_SIZE - off);
+
+		sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
+
+		off = 0;
+		len -= plen;
+	}
+	sg_mark_end(sgl->sg + npages - 1);
+	sgl->npages = npages;
+
+	return n;
+}
+EXPORT_SYMBOL_GPL(af_alg_make_sg);
+
+void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
+{
+	sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
+	sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
+}
+EXPORT_SYMBOL_GPL(af_alg_link_sg);
+
+void af_alg_free_sg(struct af_alg_sgl *sgl)
+{
+	int i;
+
+	for (i = 0; i < sgl->npages; i++)
+		put_page(sgl->pages[i]);
+}
+EXPORT_SYMBOL_GPL(af_alg_free_sg);
+
+int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
+{
+	struct cmsghdr *cmsg;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+		if (cmsg->cmsg_level != SOL_ALG)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case ALG_SET_IV:
+			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
+				return -EINVAL;
+			con->iv = (void *)CMSG_DATA(cmsg);
+			if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
+						      sizeof(*con->iv)))
+				return -EINVAL;
+			break;
+
+		case ALG_SET_OP:
+			if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
+				return -EINVAL;
+			con->op = *(u32 *)CMSG_DATA(cmsg);
+			break;
+
+		case ALG_SET_AEAD_ASSOCLEN:
+			if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
+				return -EINVAL;
+			con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
+
+/**
+ * af_alg_alloc_tsgl - allocate the TX SGL
+ *
+ * @sk socket of connection to user space
+ * @return: 0 upon success, < 0 upon error
+ */
+int af_alg_alloc_tsgl(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	struct scatterlist *sg = NULL;
+
+	sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
+	if (!list_empty(&ctx->tsgl_list))
+		sg = sgl->sg;
+
+	if (!sg || sgl->cur >= MAX_SGL_ENTS) {
+		sgl = sock_kmalloc(sk,
+				   struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
+				   GFP_KERNEL);
+		if (!sgl)
+			return -ENOMEM;
+
+		sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
+		sgl->cur = 0;
+
+		if (sg)
+			sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
+
+		list_add_tail(&sgl->list, &ctx->tsgl_list);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
+
+/**
+ * aead_count_tsgl - Count number of TX SG entries
+ *
+ * The counting starts from the beginning of the SGL to @bytes. If
+ * an offset is provided, the counting of the SG entries starts at the offset.
+ *
+ * @sk socket of connection to user space
+ * @bytes Count the number of SG entries holding given number of bytes.
+ * @offset Start the counting of SG entries from the given offset.
+ * @return Number of TX SG entries found given the constraints
+ */
+unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl, *tmp;
+	unsigned int i;
+	unsigned int sgl_count = 0;
+
+	if (!bytes)
+		return 0;
+
+	list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
+		struct scatterlist *sg = sgl->sg;
+
+		for (i = 0; i < sgl->cur; i++) {
+			size_t bytes_count;
+
+			/* Skip offset */
+			if (offset >= sg[i].length) {
+				offset -= sg[i].length;
+				bytes -= sg[i].length;
+				continue;
+			}
+
+			bytes_count = sg[i].length - offset;
+
+			offset = 0;
+			sgl_count++;
+
+			/* If we have seen requested number of bytes, stop */
+			if (bytes_count >= bytes)
+				return sgl_count;
+
+			bytes -= bytes_count;
+		}
+	}
+
+	return sgl_count;
+}
+EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
+
+/**
+ * aead_pull_tsgl - Release the specified buffers from TX SGL
+ *
+ * If @dst is non-null, reassign the pages to dst. The caller must release
+ * the pages. If @dst_offset is given only reassign the pages to @dst starting
+ * at the @dst_offset (byte). The caller must ensure that @dst is large
+ * enough (e.g. by using af_alg_count_tsgl with the same offset).
+ *
+ * @sk socket of connection to user space
+ * @used Number of bytes to pull from TX SGL
+ * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
+ *	caller must release the buffers in dst.
+ * @dst_offset Reassign the TX SGL from given offset. All buffers before
+ *	       reaching the offset is released.
+ */
+void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
+		      size_t dst_offset)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	struct scatterlist *sg;
+	unsigned int i, j = 0;
+
+	while (!list_empty(&ctx->tsgl_list)) {
+		sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
+				       list);
+		sg = sgl->sg;
+
+		for (i = 0; i < sgl->cur; i++) {
+			size_t plen = min_t(size_t, used, sg[i].length);
+			struct page *page = sg_page(sg + i);
+
+			if (!page)
+				continue;
+
+			/*
+			 * Assumption: caller created af_alg_count_tsgl(len)
+			 * SG entries in dst.
+			 */
+			if (dst) {
+				if (dst_offset >= plen) {
+					/* discard page before offset */
+					dst_offset -= plen;
+				} else {
+					/* reassign page to dst after offset */
+					get_page(page);
+					sg_set_page(dst + j, page,
+						    plen - dst_offset,
+						    sg[i].offset + dst_offset);
+					dst_offset = 0;
+					j++;
+				}
+			}
+
+			sg[i].length -= plen;
+			sg[i].offset += plen;
+
+			used -= plen;
+			ctx->used -= plen;
+
+			if (sg[i].length)
+				return;
+
+			put_page(page);
+			sg_assign_page(sg + i, NULL);
+		}
+
+		list_del(&sgl->list);
+		sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
+						     (MAX_SGL_ENTS + 1));
+	}
+
+	if (!ctx->used)
+		ctx->merge = 0;
+}
+EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
+
+/**
+ * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
+ *
+ * @areq Request holding the TX and RX SGL
+ */
+void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
+{
+	struct sock *sk = areq->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_rsgl *rsgl, *tmp;
+	struct scatterlist *tsgl;
+	struct scatterlist *sg;
+	unsigned int i;
+
+	list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
+		atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
+		af_alg_free_sg(&rsgl->sgl);
+		list_del(&rsgl->list);
+		if (rsgl != &areq->first_rsgl)
+			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
+	}
+
+	tsgl = areq->tsgl;
+	if (tsgl) {
+		for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
+			if (!sg_page(sg))
+				continue;
+			put_page(sg_page(sg));
+		}
+
+		sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
+	}
+}
+EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
+
+/**
+ * af_alg_wait_for_wmem - wait for availability of writable memory
+ *
+ * @sk socket of connection to user space
+ * @flags If MSG_DONTWAIT is set, then only report if function would sleep
+ * @return 0 when writable memory is available, < 0 upon error
+ */
+int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	int err = -ERESTARTSYS;
+	long timeout;
+
+	if (flags & MSG_DONTWAIT)
+		return -EAGAIN;
+
+	sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	for (;;) {
+		if (signal_pending(current))
+			break;
+		timeout = MAX_SCHEDULE_TIMEOUT;
+		if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
+			err = 0;
+			break;
+		}
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
+
+/**
+ * af_alg_wmem_wakeup - wakeup caller when writable memory is available
+ *
+ * @sk socket of connection to user space
+ */
+void af_alg_wmem_wakeup(struct sock *sk)
+{
+	struct socket_wq *wq;
+
+	if (!af_alg_writable(sk))
+		return;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (skwq_has_sleeper(wq))
+		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
+							   EPOLLRDNORM |
+							   EPOLLRDBAND);
+	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
+
+/**
+ * af_alg_wait_for_data - wait for availability of TX data
+ *
+ * @sk socket of connection to user space
+ * @flags If MSG_DONTWAIT is set, then only report if function would sleep
+ * @return 0 when writable memory is available, < 0 upon error
+ */
+int af_alg_wait_for_data(struct sock *sk, unsigned flags)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	long timeout;
+	int err = -ERESTARTSYS;
+
+	if (flags & MSG_DONTWAIT)
+		return -EAGAIN;
+
+	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	for (;;) {
+		if (signal_pending(current))
+			break;
+		timeout = MAX_SCHEDULE_TIMEOUT;
+		if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
+				  &wait)) {
+			err = 0;
+			break;
+		}
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+
+	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
+
+/**
+ * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
+ *
+ * @sk socket of connection to user space
+ */
+
+void af_alg_data_wakeup(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct socket_wq *wq;
+
+	if (!ctx->used)
+		return;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (skwq_has_sleeper(wq))
+		wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
+							   EPOLLRDNORM |
+							   EPOLLRDBAND);
+	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
+
+/**
+ * af_alg_sendmsg - implementation of sendmsg system call handler
+ *
+ * The sendmsg system call handler obtains the user data and stores it
+ * in ctx->tsgl_list. This implies allocation of the required numbers of
+ * struct af_alg_tsgl.
+ *
+ * In addition, the ctx is filled with the information sent via CMSG.
+ *
+ * @sock socket of connection to user space
+ * @msg message from user space
+ * @size size of message from user space
+ * @ivsize the size of the IV for the cipher operation to verify that the
+ *	   user-space-provided IV has the right size
+ * @return the number of copied data upon success, < 0 upon error
+ */
+int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		   unsigned int ivsize)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	struct af_alg_control con = {};
+	long copied = 0;
+	bool enc = 0;
+	bool init = 0;
+	int err = 0;
+
+	if (msg->msg_controllen) {
+		err = af_alg_cmsg_send(msg, &con);
+		if (err)
+			return err;
+
+		init = 1;
+		switch (con.op) {
+		case ALG_OP_ENCRYPT:
+			enc = 1;
+			break;
+		case ALG_OP_DECRYPT:
+			enc = 0;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		if (con.iv && con.iv->ivlen != ivsize)
+			return -EINVAL;
+	}
+
+	lock_sock(sk);
+	if (!ctx->more && ctx->used) {
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	if (init) {
+		ctx->enc = enc;
+		if (con.iv)
+			memcpy(ctx->iv, con.iv->iv, ivsize);
+
+		ctx->aead_assoclen = con.aead_assoclen;
+	}
+
+	while (size) {
+		struct scatterlist *sg;
+		size_t len = size;
+		size_t plen;
+
+		/* use the existing memory in an allocated page */
+		if (ctx->merge) {
+			sgl = list_entry(ctx->tsgl_list.prev,
+					 struct af_alg_tsgl, list);
+			sg = sgl->sg + sgl->cur - 1;
+			len = min_t(size_t, len,
+				    PAGE_SIZE - sg->offset - sg->length);
+
+			err = memcpy_from_msg(page_address(sg_page(sg)) +
+					      sg->offset + sg->length,
+					      msg, len);
+			if (err)
+				goto unlock;
+
+			sg->length += len;
+			ctx->merge = (sg->offset + sg->length) &
+				     (PAGE_SIZE - 1);
+
+			ctx->used += len;
+			copied += len;
+			size -= len;
+			continue;
+		}
+
+		if (!af_alg_writable(sk)) {
+			err = af_alg_wait_for_wmem(sk, msg->msg_flags);
+			if (err)
+				goto unlock;
+		}
+
+		/* allocate a new page */
+		len = min_t(unsigned long, len, af_alg_sndbuf(sk));
+
+		err = af_alg_alloc_tsgl(sk);
+		if (err)
+			goto unlock;
+
+		sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
+				 list);
+		sg = sgl->sg;
+		if (sgl->cur)
+			sg_unmark_end(sg + sgl->cur - 1);
+
+		do {
+			unsigned int i = sgl->cur;
+
+			plen = min_t(size_t, len, PAGE_SIZE);
+
+			sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
+			if (!sg_page(sg + i)) {
+				err = -ENOMEM;
+				goto unlock;
+			}
+
+			err = memcpy_from_msg(page_address(sg_page(sg + i)),
+					      msg, plen);
+			if (err) {
+				__free_page(sg_page(sg + i));
+				sg_assign_page(sg + i, NULL);
+				goto unlock;
+			}
+
+			sg[i].length = plen;
+			len -= plen;
+			ctx->used += plen;
+			copied += plen;
+			size -= plen;
+			sgl->cur++;
+		} while (len && sgl->cur < MAX_SGL_ENTS);
+
+		if (!size)
+			sg_mark_end(sg + sgl->cur - 1);
+
+		ctx->merge = plen & (PAGE_SIZE - 1);
+	}
+
+	err = 0;
+
+	ctx->more = msg->msg_flags & MSG_MORE;
+
+unlock:
+	af_alg_data_wakeup(sk);
+	release_sock(sk);
+
+	return copied ?: err;
+}
+EXPORT_SYMBOL_GPL(af_alg_sendmsg);
+
+/**
+ * af_alg_sendpage - sendpage system call handler
+ *
+ * This is a generic implementation of sendpage to fill ctx->tsgl_list.
+ */
+ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
+			int offset, size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	int err = -EINVAL;
+
+	if (flags & MSG_SENDPAGE_NOTLAST)
+		flags |= MSG_MORE;
+
+	lock_sock(sk);
+	if (!ctx->more && ctx->used)
+		goto unlock;
+
+	if (!size)
+		goto done;
+
+	if (!af_alg_writable(sk)) {
+		err = af_alg_wait_for_wmem(sk, flags);
+		if (err)
+			goto unlock;
+	}
+
+	err = af_alg_alloc_tsgl(sk);
+	if (err)
+		goto unlock;
+
+	ctx->merge = 0;
+	sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
+
+	if (sgl->cur)
+		sg_unmark_end(sgl->sg + sgl->cur - 1);
+
+	sg_mark_end(sgl->sg + sgl->cur);
+
+	get_page(page);
+	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
+	sgl->cur++;
+	ctx->used += size;
+
+done:
+	ctx->more = flags & MSG_MORE;
+
+unlock:
+	af_alg_data_wakeup(sk);
+	release_sock(sk);
+
+	return err ?: size;
+}
+EXPORT_SYMBOL_GPL(af_alg_sendpage);
+
+/**
+ * af_alg_free_resources - release resources required for crypto request
+ */
+void af_alg_free_resources(struct af_alg_async_req *areq)
+{
+	struct sock *sk = areq->sk;
+
+	af_alg_free_areq_sgls(areq);
+	sock_kfree_s(sk, areq, areq->areqlen);
+}
+EXPORT_SYMBOL_GPL(af_alg_free_resources);
+
+/**
+ * af_alg_async_cb - AIO callback handler
+ *
+ * This handler cleans up the struct af_alg_async_req upon completion of the
+ * AIO operation.
+ *
+ * The number of bytes to be generated with the AIO operation must be set
+ * in areq->outlen before the AIO callback handler is invoked.
+ */
+void af_alg_async_cb(struct crypto_async_request *_req, int err)
+{
+	struct af_alg_async_req *areq = _req->data;
+	struct sock *sk = areq->sk;
+	struct kiocb *iocb = areq->iocb;
+	unsigned int resultlen;
+
+	/* Buffer size written by crypto operation. */
+	resultlen = areq->outlen;
+
+	af_alg_free_resources(areq);
+	sock_put(sk);
+
+	iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
+}
+EXPORT_SYMBOL_GPL(af_alg_async_cb);
+
+/**
+ * af_alg_poll - poll system call handler
+ */
+__poll_t af_alg_poll(struct file *file, struct socket *sock,
+			 poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	__poll_t mask;
+
+	sock_poll_wait(file, sock, wait);
+	mask = 0;
+
+	if (!ctx->more || ctx->used)
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	if (af_alg_writable(sk))
+		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
+
+	return mask;
+}
+EXPORT_SYMBOL_GPL(af_alg_poll);
+
+/**
+ * af_alg_alloc_areq - allocate struct af_alg_async_req
+ *
+ * @sk socket of connection to user space
+ * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
+ * @return allocated data structure or ERR_PTR upon error
+ */
+struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
+					   unsigned int areqlen)
+{
+	struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
+
+	if (unlikely(!areq))
+		return ERR_PTR(-ENOMEM);
+
+	areq->areqlen = areqlen;
+	areq->sk = sk;
+	areq->last_rsgl = NULL;
+	INIT_LIST_HEAD(&areq->rsgl_list);
+	areq->tsgl = NULL;
+	areq->tsgl_entries = 0;
+
+	return areq;
+}
+EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
+
+/**
+ * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
+ *		     operation
+ *
+ * @sk socket of connection to user space
+ * @msg user space message
+ * @flags flags used to invoke recvmsg with
+ * @areq instance of the cryptographic request that will hold the RX SGL
+ * @maxsize maximum number of bytes to be pulled from user space
+ * @outlen number of bytes in the RX SGL
+ * @return 0 on success, < 0 upon error
+ */
+int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
+		    struct af_alg_async_req *areq, size_t maxsize,
+		    size_t *outlen)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	size_t len = 0;
+
+	while (maxsize > len && msg_data_left(msg)) {
+		struct af_alg_rsgl *rsgl;
+		size_t seglen;
+		int err;
+
+		/* limit the amount of readable buffers */
+		if (!af_alg_readable(sk))
+			break;
+
+		seglen = min_t(size_t, (maxsize - len),
+			       msg_data_left(msg));
+
+		if (list_empty(&areq->rsgl_list)) {
+			rsgl = &areq->first_rsgl;
+		} else {
+			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
+			if (unlikely(!rsgl))
+				return -ENOMEM;
+		}
+
+		rsgl->sgl.npages = 0;
+		list_add_tail(&rsgl->list, &areq->rsgl_list);
+
+		/* make one iovec available as scatterlist */
+		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
+		if (err < 0) {
+			rsgl->sg_num_bytes = 0;
+			return err;
+		}
+
+		/* chain the new scatterlist with previous one */
+		if (areq->last_rsgl)
+			af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
+
+		areq->last_rsgl = rsgl;
+		len += err;
+		atomic_add(err, &ctx->rcvused);
+		rsgl->sg_num_bytes = err;
+		iov_iter_advance(&msg->msg_iter, err);
+	}
+
+	*outlen = len;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
+
+static int __init af_alg_init(void)
+{
+	int err = proto_register(&alg_proto, 0);
+
+	if (err)
+		goto out;
+
+	err = sock_register(&alg_family);
+	if (err != 0)
+		goto out_unregister_proto;
+
+out:
+	return err;
+
+out_unregister_proto:
+	proto_unregister(&alg_proto);
+	goto out;
+}
+
+static void __exit af_alg_exit(void)
+{
+	sock_unregister(PF_ALG);
+	proto_unregister(&alg_proto);
+}
+
+module_init(af_alg_init);
+module_exit(af_alg_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(AF_ALG);