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-rw-r--r--net/tls/tls_device_fallback.c450
1 files changed, 450 insertions, 0 deletions
diff --git a/net/tls/tls_device_fallback.c b/net/tls/tls_device_fallback.c
new file mode 100644
index 0000000000000..748914abdb604
--- /dev/null
+++ b/net/tls/tls_device_fallback.c
@@ -0,0 +1,450 @@
+/* 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>
+
+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), 0, 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)
+{
+ unsigned char buf[TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE];
+ struct scatterlist sg_in[3];
+ struct scatterlist sg_out[3];
+ u16 len;
+ int rc;
+
+ len = min_t(int, *in_len, ARRAY_SIZE(buf));
+
+ 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 -= TLS_CIPHER_AES_GCM_128_IV_SIZE;
+
+ tls_make_aad(aad, len - TLS_CIPHER_AES_GCM_128_TAG_SIZE,
+ (char *)&rcd_sn, sizeof(rcd_sn), buf[0]);
+
+ memcpy(iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, buf + TLS_HEADER_SIZE,
+ TLS_CIPHER_AES_GCM_128_IV_SIZE);
+
+ 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 += TLS_CIPHER_AES_GCM_128_TAG_SIZE;
+ /* 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 -= TLS_CIPHER_AES_GCM_128_TAG_SIZE;
+ 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 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);
+ 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)
+{
+ skb_copy_header(nskb, skb);
+
+ skb_put(nskb, skb->len);
+ memcpy(nskb->data, skb->data, headln);
+ update_chksum(nskb, headln);
+
+ nskb->destructor = skb->destructor;
+ nskb->sk = skb->sk;
+ skb->destructor = NULL;
+ skb->sk = NULL;
+ refcount_add(nskb->truesize - skb->truesize,
+ &nskb->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 *ctx,
+ u64 *rcd_sn,
+ s32 *sync_size,
+ int *resync_sgs)
+{
+ int tcp_payload_offset = skb_transport_offset(skb) + tcp_hdrlen(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);
+ WARN(1, "Record not found for seq %u\n", tcp_seq);
+ 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), frag->page_offset);
+
+ 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)
+{
+ 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, TLS_CIPHER_AES_GCM_128_TAG_SIZE);
+}
+
+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)
+{
+ int tcp_payload_offset = skb_transport_offset(skb) + tcp_hdrlen(skb);
+ struct tls_offload_context *ctx = tls_offload_ctx(tls_ctx);
+ int payload_len = skb->len - tcp_payload_offset;
+ void *buf, *iv, *aad, *dummy_buf;
+ 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;
+
+ buf_len = TLS_CIPHER_AES_GCM_128_SALT_SIZE +
+ TLS_CIPHER_AES_GCM_128_IV_SIZE +
+ TLS_AAD_SPACE_SIZE +
+ sync_size +
+ TLS_CIPHER_AES_GCM_128_TAG_SIZE;
+ buf = kmalloc(buf_len, GFP_ATOMIC);
+ if (!buf)
+ goto free_req;
+
+ iv = buf;
+ memcpy(iv, tls_ctx->crypto_send_aes_gcm_128.salt,
+ TLS_CIPHER_AES_GCM_128_SALT_SIZE);
+ aad = buf + TLS_CIPHER_AES_GCM_128_SALT_SIZE +
+ TLS_CIPHER_AES_GCM_128_IV_SIZE;
+ 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) < 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_transport_offset(skb) + tcp_hdrlen(skb);
+ struct tls_context *tls_ctx = tls_get_ctx(sk);
+ struct tls_offload_context *ctx = tls_offload_ctx(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:
+ 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 == tls_get_ctx(sk)->netdev)
+ return skb;
+
+ return tls_sw_fallback(sk, skb);
+}
+
+int tls_sw_fallback_init(struct sock *sk,
+ struct tls_offload_context *offload_ctx,
+ struct tls_crypto_info *crypto_info)
+{
+ 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;
+ }
+
+ key = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->key;
+
+ rc = crypto_aead_setkey(offload_ctx->aead_send, key,
+ TLS_CIPHER_AES_GCM_128_KEY_SIZE);
+ if (rc)
+ goto free_aead;
+
+ rc = crypto_aead_setauthsize(offload_ctx->aead_send,
+ TLS_CIPHER_AES_GCM_128_TAG_SIZE);
+ if (rc)
+ goto free_aead;
+
+ return 0;
+free_aead:
+ crypto_free_aead(offload_ctx->aead_send);
+err_out:
+ return rc;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-26 01:04:15 +0000