1 files changed, 513 insertions, 0 deletions

diff --git a/net/tls/tls_device_fallback.c b/net/tls/tls_device_fallback.c
new file mode 100644
index 000000000..7fbb1d0b6
--- /dev/null
+++ b/net/tls/tls_device_fallback.c
@@ -0,0 +1,513 @@
+/* Copyright (c) 2018, Mellanox Technologies 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 <net/tls.h>
+#include <crypto/aead.h>
+#include <crypto/scatterwalk.h>
+#include <net/ip6_checksum.h>
+
+#include "tls.h"
+
+static void chain_to_walk(struct scatterlist *sg, struct scatter_walk *walk)
+{
+	struct scatterlist *src = walk->sg;
+	int diff = walk->offset - src->offset;
+
+	sg_set_page(sg, sg_page(src),
+		    src->length - diff, walk->offset);
+
+	scatterwalk_crypto_chain(sg, sg_next(src), 2);
+}
+
+static int tls_enc_record(struct aead_request *aead_req,
+			  struct crypto_aead *aead, char *aad,
+			  char *iv, __be64 rcd_sn,
+			  struct scatter_walk *in,
+			  struct scatter_walk *out, int *in_len,
+			  struct tls_prot_info *prot)
+{
+	unsigned char buf[TLS_HEADER_SIZE + MAX_IV_SIZE];
+	const struct tls_cipher_size_desc *cipher_sz;
+	struct scatterlist sg_in[3];
+	struct scatterlist sg_out[3];
+	unsigned int buf_size;
+	u16 len;
+	int rc;
+
+	switch (prot->cipher_type) {
+	case TLS_CIPHER_AES_GCM_128:
+	case TLS_CIPHER_AES_GCM_256:
+		break;
+	default:
+		return -EINVAL;
+	}
+	cipher_sz = &tls_cipher_size_desc[prot->cipher_type];
+
+	buf_size = TLS_HEADER_SIZE + cipher_sz->iv;
+	len = min_t(int, *in_len, buf_size);
+
+	scatterwalk_copychunks(buf, in, len, 0);
+	scatterwalk_copychunks(buf, out, len, 1);
+
+	*in_len -= len;
+	if (!*in_len)
+		return 0;
+
+	scatterwalk_pagedone(in, 0, 1);
+	scatterwalk_pagedone(out, 1, 1);
+
+	len = buf[4] | (buf[3] << 8);
+	len -= cipher_sz->iv;
+
+	tls_make_aad(aad, len - cipher_sz->tag, (char *)&rcd_sn, buf[0], prot);
+
+	memcpy(iv + cipher_sz->salt, buf + TLS_HEADER_SIZE, cipher_sz->iv);
+
+	sg_init_table(sg_in, ARRAY_SIZE(sg_in));
+	sg_init_table(sg_out, ARRAY_SIZE(sg_out));
+	sg_set_buf(sg_in, aad, TLS_AAD_SPACE_SIZE);
+	sg_set_buf(sg_out, aad, TLS_AAD_SPACE_SIZE);
+	chain_to_walk(sg_in + 1, in);
+	chain_to_walk(sg_out + 1, out);
+
+	*in_len -= len;
+	if (*in_len < 0) {
+		*in_len += cipher_sz->tag;
+		/* the input buffer doesn't contain the entire record.
+		 * trim len accordingly. The resulting authentication tag
+		 * will contain garbage, but we don't care, so we won't
+		 * include any of it in the output skb
+		 * Note that we assume the output buffer length
+		 * is larger then input buffer length + tag size
+		 */
+		if (*in_len < 0)
+			len += *in_len;
+
+		*in_len = 0;
+	}
+
+	if (*in_len) {
+		scatterwalk_copychunks(NULL, in, len, 2);
+		scatterwalk_pagedone(in, 0, 1);
+		scatterwalk_copychunks(NULL, out, len, 2);
+		scatterwalk_pagedone(out, 1, 1);
+	}
+
+	len -= cipher_sz->tag;
+	aead_request_set_crypt(aead_req, sg_in, sg_out, len, iv);
+
+	rc = crypto_aead_encrypt(aead_req);
+
+	return rc;
+}
+
+static void tls_init_aead_request(struct aead_request *aead_req,
+				  struct crypto_aead *aead)
+{
+	aead_request_set_tfm(aead_req, aead);
+	aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
+}
+
+static struct aead_request *tls_alloc_aead_request(struct crypto_aead *aead,
+						   gfp_t flags)
+{
+	unsigned int req_size = sizeof(struct aead_request) +
+		crypto_aead_reqsize(aead);
+	struct aead_request *aead_req;
+
+	aead_req = kzalloc(req_size, flags);
+	if (aead_req)
+		tls_init_aead_request(aead_req, aead);
+	return aead_req;
+}
+
+static int tls_enc_records(struct aead_request *aead_req,
+			   struct crypto_aead *aead, struct scatterlist *sg_in,
+			   struct scatterlist *sg_out, char *aad, char *iv,
+			   u64 rcd_sn, int len, struct tls_prot_info *prot)
+{
+	struct scatter_walk out, in;
+	int rc;
+
+	scatterwalk_start(&in, sg_in);
+	scatterwalk_start(&out, sg_out);
+
+	do {
+		rc = tls_enc_record(aead_req, aead, aad, iv,
+				    cpu_to_be64(rcd_sn), &in, &out, &len, prot);
+		rcd_sn++;
+
+	} while (rc == 0 && len);
+
+	scatterwalk_done(&in, 0, 0);
+	scatterwalk_done(&out, 1, 0);
+
+	return rc;
+}
+
+/* Can't use icsk->icsk_af_ops->send_check here because the ip addresses
+ * might have been changed by NAT.
+ */
+static void update_chksum(struct sk_buff *skb, int headln)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+	int datalen = skb->len - headln;
+	const struct ipv6hdr *ipv6h;
+	const struct iphdr *iph;
+
+	/* We only changed the payload so if we are using partial we don't
+	 * need to update anything.
+	 */
+	if (likely(skb->ip_summed == CHECKSUM_PARTIAL))
+		return;
+
+	skb->ip_summed = CHECKSUM_PARTIAL;
+	skb->csum_start = skb_transport_header(skb) - skb->head;
+	skb->csum_offset = offsetof(struct tcphdr, check);
+
+	if (skb->sk->sk_family == AF_INET6) {
+		ipv6h = ipv6_hdr(skb);
+		th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
+					     datalen, IPPROTO_TCP, 0);
+	} else {
+		iph = ip_hdr(skb);
+		th->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen,
+					       IPPROTO_TCP, 0);
+	}
+}
+
+static void complete_skb(struct sk_buff *nskb, struct sk_buff *skb, int headln)
+{
+	struct sock *sk = skb->sk;
+	int delta;
+
+	skb_copy_header(nskb, skb);
+
+	skb_put(nskb, skb->len);
+	memcpy(nskb->data, skb->data, headln);
+
+	nskb->destructor = skb->destructor;
+	nskb->sk = sk;
+	skb->destructor = NULL;
+	skb->sk = NULL;
+
+	update_chksum(nskb, headln);
+
+	/* sock_efree means skb must gone through skb_orphan_partial() */
+	if (nskb->destructor == sock_efree)
+		return;
+
+	delta = nskb->truesize - skb->truesize;
+	if (likely(delta < 0))
+		WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc));
+	else if (delta)
+		refcount_add(delta, &sk->sk_wmem_alloc);
+}
+
+/* This function may be called after the user socket is already
+ * closed so make sure we don't use anything freed during
+ * tls_sk_proto_close here
+ */
+
+static int fill_sg_in(struct scatterlist *sg_in,
+		      struct sk_buff *skb,
+		      struct tls_offload_context_tx *ctx,
+		      u64 *rcd_sn,
+		      s32 *sync_size,
+		      int *resync_sgs)
+{
+	int tcp_payload_offset = skb_tcp_all_headers(skb);
+	int payload_len = skb->len - tcp_payload_offset;
+	u32 tcp_seq = ntohl(tcp_hdr(skb)->seq);
+	struct tls_record_info *record;
+	unsigned long flags;
+	int remaining;
+	int i;
+
+	spin_lock_irqsave(&ctx->lock, flags);
+	record = tls_get_record(ctx, tcp_seq, rcd_sn);
+	if (!record) {
+		spin_unlock_irqrestore(&ctx->lock, flags);
+		return -EINVAL;
+	}
+
+	*sync_size = tcp_seq - tls_record_start_seq(record);
+	if (*sync_size < 0) {
+		int is_start_marker = tls_record_is_start_marker(record);
+
+		spin_unlock_irqrestore(&ctx->lock, flags);
+		/* This should only occur if the relevant record was
+		 * already acked. In that case it should be ok
+		 * to drop the packet and avoid retransmission.
+		 *
+		 * There is a corner case where the packet contains
+		 * both an acked and a non-acked record.
+		 * We currently don't handle that case and rely
+		 * on TCP to retranmit a packet that doesn't contain
+		 * already acked payload.
+		 */
+		if (!is_start_marker)
+			*sync_size = 0;
+		return -EINVAL;
+	}
+
+	remaining = *sync_size;
+	for (i = 0; remaining > 0; i++) {
+		skb_frag_t *frag = &record->frags[i];
+
+		__skb_frag_ref(frag);
+		sg_set_page(sg_in + i, skb_frag_page(frag),
+			    skb_frag_size(frag), skb_frag_off(frag));
+
+		remaining -= skb_frag_size(frag);
+
+		if (remaining < 0)
+			sg_in[i].length += remaining;
+	}
+	*resync_sgs = i;
+
+	spin_unlock_irqrestore(&ctx->lock, flags);
+	if (skb_to_sgvec(skb, &sg_in[i], tcp_payload_offset, payload_len) < 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void fill_sg_out(struct scatterlist sg_out[3], void *buf,
+			struct tls_context *tls_ctx,
+			struct sk_buff *nskb,
+			int tcp_payload_offset,
+			int payload_len,
+			int sync_size,
+			void *dummy_buf)
+{
+	const struct tls_cipher_size_desc *cipher_sz =
+		&tls_cipher_size_desc[tls_ctx->crypto_send.info.cipher_type];
+
+	sg_set_buf(&sg_out[0], dummy_buf, sync_size);
+	sg_set_buf(&sg_out[1], nskb->data + tcp_payload_offset, payload_len);
+	/* Add room for authentication tag produced by crypto */
+	dummy_buf += sync_size;
+	sg_set_buf(&sg_out[2], dummy_buf, cipher_sz->tag);
+}
+
+static struct sk_buff *tls_enc_skb(struct tls_context *tls_ctx,
+				   struct scatterlist sg_out[3],
+				   struct scatterlist *sg_in,
+				   struct sk_buff *skb,
+				   s32 sync_size, u64 rcd_sn)
+{
+	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
+	int tcp_payload_offset = skb_tcp_all_headers(skb);
+	int payload_len = skb->len - tcp_payload_offset;
+	const struct tls_cipher_size_desc *cipher_sz;
+	void *buf, *iv, *aad, *dummy_buf, *salt;
+	struct aead_request *aead_req;
+	struct sk_buff *nskb = NULL;
+	int buf_len;
+
+	aead_req = tls_alloc_aead_request(ctx->aead_send, GFP_ATOMIC);
+	if (!aead_req)
+		return NULL;
+
+	switch (tls_ctx->crypto_send.info.cipher_type) {
+	case TLS_CIPHER_AES_GCM_128:
+		salt = tls_ctx->crypto_send.aes_gcm_128.salt;
+		break;
+	case TLS_CIPHER_AES_GCM_256:
+		salt = tls_ctx->crypto_send.aes_gcm_256.salt;
+		break;
+	default:
+		goto free_req;
+	}
+	cipher_sz = &tls_cipher_size_desc[tls_ctx->crypto_send.info.cipher_type];
+	buf_len = cipher_sz->salt + cipher_sz->iv + TLS_AAD_SPACE_SIZE +
+		  sync_size + cipher_sz->tag;
+	buf = kmalloc(buf_len, GFP_ATOMIC);
+	if (!buf)
+		goto free_req;
+
+	iv = buf;
+	memcpy(iv, salt, cipher_sz->salt);
+	aad = buf + cipher_sz->salt + cipher_sz->iv;
+	dummy_buf = aad + TLS_AAD_SPACE_SIZE;
+
+	nskb = alloc_skb(skb_headroom(skb) + skb->len, GFP_ATOMIC);
+	if (!nskb)
+		goto free_buf;
+
+	skb_reserve(nskb, skb_headroom(skb));
+
+	fill_sg_out(sg_out, buf, tls_ctx, nskb, tcp_payload_offset,
+		    payload_len, sync_size, dummy_buf);
+
+	if (tls_enc_records(aead_req, ctx->aead_send, sg_in, sg_out, aad, iv,
+			    rcd_sn, sync_size + payload_len,
+			    &tls_ctx->prot_info) < 0)
+		goto free_nskb;
+
+	complete_skb(nskb, skb, tcp_payload_offset);
+
+	/* validate_xmit_skb_list assumes that if the skb wasn't segmented
+	 * nskb->prev will point to the skb itself
+	 */
+	nskb->prev = nskb;
+
+free_buf:
+	kfree(buf);
+free_req:
+	kfree(aead_req);
+	return nskb;
+free_nskb:
+	kfree_skb(nskb);
+	nskb = NULL;
+	goto free_buf;
+}
+
+static struct sk_buff *tls_sw_fallback(struct sock *sk, struct sk_buff *skb)
+{
+	int tcp_payload_offset = skb_tcp_all_headers(skb);
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
+	int payload_len = skb->len - tcp_payload_offset;
+	struct scatterlist *sg_in, sg_out[3];
+	struct sk_buff *nskb = NULL;
+	int sg_in_max_elements;
+	int resync_sgs = 0;
+	s32 sync_size = 0;
+	u64 rcd_sn;
+
+	/* worst case is:
+	 * MAX_SKB_FRAGS in tls_record_info
+	 * MAX_SKB_FRAGS + 1 in SKB head and frags.
+	 */
+	sg_in_max_elements = 2 * MAX_SKB_FRAGS + 1;
+
+	if (!payload_len)
+		return skb;
+
+	sg_in = kmalloc_array(sg_in_max_elements, sizeof(*sg_in), GFP_ATOMIC);
+	if (!sg_in)
+		goto free_orig;
+
+	sg_init_table(sg_in, sg_in_max_elements);
+	sg_init_table(sg_out, ARRAY_SIZE(sg_out));
+
+	if (fill_sg_in(sg_in, skb, ctx, &rcd_sn, &sync_size, &resync_sgs)) {
+		/* bypass packets before kernel TLS socket option was set */
+		if (sync_size < 0 && payload_len <= -sync_size)
+			nskb = skb_get(skb);
+		goto put_sg;
+	}
+
+	nskb = tls_enc_skb(tls_ctx, sg_out, sg_in, skb, sync_size, rcd_sn);
+
+put_sg:
+	while (resync_sgs)
+		put_page(sg_page(&sg_in[--resync_sgs]));
+	kfree(sg_in);
+free_orig:
+	if (nskb)
+		consume_skb(skb);
+	else
+		kfree_skb(skb);
+	return nskb;
+}
+
+struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
+				      struct net_device *dev,
+				      struct sk_buff *skb)
+{
+	if (dev == rcu_dereference_bh(tls_get_ctx(sk)->netdev) ||
+	    netif_is_bond_master(dev))
+		return skb;
+
+	return tls_sw_fallback(sk, skb);
+}
+EXPORT_SYMBOL_GPL(tls_validate_xmit_skb);
+
+struct sk_buff *tls_validate_xmit_skb_sw(struct sock *sk,
+					 struct net_device *dev,
+					 struct sk_buff *skb)
+{
+	return tls_sw_fallback(sk, skb);
+}
+
+struct sk_buff *tls_encrypt_skb(struct sk_buff *skb)
+{
+	return tls_sw_fallback(skb->sk, skb);
+}
+EXPORT_SYMBOL_GPL(tls_encrypt_skb);
+
+int tls_sw_fallback_init(struct sock *sk,
+			 struct tls_offload_context_tx *offload_ctx,
+			 struct tls_crypto_info *crypto_info)
+{
+	const struct tls_cipher_size_desc *cipher_sz;
+	const u8 *key;
+	int rc;
+
+	offload_ctx->aead_send =
+	    crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(offload_ctx->aead_send)) {
+		rc = PTR_ERR(offload_ctx->aead_send);
+		pr_err_ratelimited("crypto_alloc_aead failed rc=%d\n", rc);
+		offload_ctx->aead_send = NULL;
+		goto err_out;
+	}
+
+	switch (crypto_info->cipher_type) {
+	case TLS_CIPHER_AES_GCM_128:
+		key = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->key;
+		break;
+	case TLS_CIPHER_AES_GCM_256:
+		key = ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->key;
+		break;
+	default:
+		rc = -EINVAL;
+		goto free_aead;
+	}
+	cipher_sz = &tls_cipher_size_desc[crypto_info->cipher_type];
+
+	rc = crypto_aead_setkey(offload_ctx->aead_send, key, cipher_sz->key);
+	if (rc)
+		goto free_aead;
+
+	rc = crypto_aead_setauthsize(offload_ctx->aead_send, cipher_sz->tag);
+	if (rc)
+		goto free_aead;
+
+	return 0;
+free_aead:
+	crypto_free_aead(offload_ctx->aead_send);
+err_out:
+	return rc;
+}