path: root/net/tls/tls_main.c

/*
 * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
 * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/module.h>

#include <net/tcp.h>
#include <net/inet_common.h>
#include <linux/highmem.h>
#include <linux/netdevice.h>
#include <linux/sched/signal.h>
#include <linux/inetdevice.h>
#include <linux/inet_diag.h>

#include <net/snmp.h>
#include <net/tls.h>
#include <net/tls_toe.h>

MODULE_AUTHOR("Mellanox Technologies");
MODULE_DESCRIPTION("Transport Layer Security Support");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS_TCP_ULP("tls");

enum {
	TLSV4,
	TLSV6,
	TLS_NUM_PROTS,
};

static const struct proto *saved_tcpv6_prot;
static DEFINE_MUTEX(tcpv6_prot_mutex);
static const struct proto *saved_tcpv4_prot;
static DEFINE_MUTEX(tcpv4_prot_mutex);
static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
static struct proto_ops tls_proto_ops[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
			 const struct proto *base);

void update_sk_prot(struct sock *sk, struct tls_context *ctx)
{
	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;

	WRITE_ONCE(sk->sk_prot,
		   &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf]);
	WRITE_ONCE(sk->sk_socket->ops,
		   &tls_proto_ops[ip_ver][ctx->tx_conf][ctx->rx_conf]);
}

int wait_on_pending_writer(struct sock *sk, long *timeo)
{
	int rc = 0;
	DEFINE_WAIT_FUNC(wait, woken_wake_function);

	add_wait_queue(sk_sleep(sk), &wait);
	while (1) {
		if (!*timeo) {
			rc = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			rc = sock_intr_errno(*timeo);
			break;
		}

		if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
			break;
	}
	remove_wait_queue(sk_sleep(sk), &wait);
	return rc;
}

int tls_push_sg(struct sock *sk,
		struct tls_context *ctx,
		struct scatterlist *sg,
		u16 first_offset,
		int flags)
{
	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
	int ret = 0;
	struct page *p;
	size_t size;
	int offset = first_offset;

	size = sg->length - offset;
	offset += sg->offset;

	ctx->in_tcp_sendpages = true;
	while (1) {
		if (sg_is_last(sg))
			sendpage_flags = flags;

		/* is sending application-limited? */
		tcp_rate_check_app_limited(sk);
		p = sg_page(sg);
retry:
		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);

		if (ret != size) {
			if (ret > 0) {
				offset += ret;
				size -= ret;
				goto retry;
			}

			offset -= sg->offset;
			ctx->partially_sent_offset = offset;
			ctx->partially_sent_record = (void *)sg;
			ctx->in_tcp_sendpages = false;
			return ret;
		}

		put_page(p);
		sk_mem_uncharge(sk, sg->length);
		sg = sg_next(sg);
		if (!sg)
			break;

		offset = sg->offset;
		size = sg->length;
	}

	ctx->in_tcp_sendpages = false;

	return 0;
}

static int tls_handle_open_record(struct sock *sk, int flags)
{
	struct tls_context *ctx = tls_get_ctx(sk);

	if (tls_is_pending_open_record(ctx))
		return ctx->push_pending_record(sk, flags);

	return 0;
}

int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
		      unsigned char *record_type)
{
	struct cmsghdr *cmsg;
	int rc = -EINVAL;

	for_each_cmsghdr(cmsg, msg) {
		if (!CMSG_OK(msg, cmsg))
			return -EINVAL;
		if (cmsg->cmsg_level != SOL_TLS)
			continue;

		switch (cmsg->cmsg_type) {
		case TLS_SET_RECORD_TYPE:
			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*