| /* 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), 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], |
| TLS_1_2_VERSION); |
| |
| 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_tx *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_tx *ctx = tls_offload_ctx_tx(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_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: |
| 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); |
| } |
| EXPORT_SYMBOL_GPL(tls_validate_xmit_skb); |
| |
| int tls_sw_fallback_init(struct sock *sk, |
| struct tls_offload_context_tx *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; |
| } |