From b89fec54fd614ffa4b7567edfae8b9e56c07ff69 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 7 Jul 2022 18:03:11 -0700 Subject: tls: rx: wrap decrypt params in a struct The max size of iv + aad + tail is 22B. That's smaller than a single sg entry (32B). Don't bother with the memory packing, just create a struct which holds the max size of those members. Signed-off-by: Jakub Kicinski --- net/tls/tls_sw.c | 60 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 30 insertions(+), 30 deletions(-) (limited to 'net/tls') diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 377c0f608167..5965649362a5 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -50,6 +50,13 @@ struct tls_decrypt_arg { u8 tail; }; +struct tls_decrypt_ctx { + u8 iv[MAX_IV_SIZE]; + u8 aad[TLS_MAX_AAD_SIZE]; + u8 tail; + struct scatterlist sg[]; +}; + noinline void tls_err_abort(struct sock *sk, int err) { WARN_ON_ONCE(err >= 0); @@ -1414,17 +1421,18 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, struct tls_context *tls_ctx = tls_get_ctx(sk); struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx); struct tls_prot_info *prot = &tls_ctx->prot_info; + int n_sgin, n_sgout, aead_size, err, pages = 0; struct strp_msg *rxm = strp_msg(skb); struct tls_msg *tlm = tls_msg(skb); - int n_sgin, n_sgout, nsg, mem_size, aead_size, err, pages = 0; - u8 *aad, *iv, *tail, *mem = NULL; struct aead_request *aead_req; struct sk_buff *unused; struct scatterlist *sgin = NULL; struct scatterlist *sgout = NULL; const int data_len = rxm->full_len - prot->overhead_size; int tail_pages = !!prot->tail_size; + struct tls_decrypt_ctx *dctx; int iv_offset = 0; + u8 *mem; if (darg->zc && (out_iov || out_sg)) { if (out_iov) @@ -1446,38 +1454,30 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, /* Increment to accommodate AAD */ n_sgin = n_sgin + 1; - nsg = n_sgin + n_sgout; - - aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv); - mem_size = aead_size + (nsg * sizeof(struct scatterlist)); - mem_size = mem_size + TLS_MAX_AAD_SIZE; - mem_size = mem_size + MAX_IV_SIZE; - mem_size = mem_size + prot->tail_size; - /* Allocate a single block of memory which contains - * aead_req || sgin[] || sgout[] || aad || iv || tail. - * This order achieves correct alignment for aead_req, sgin, sgout. + * aead_req || tls_decrypt_ctx. + * Both structs are variable length. */ - mem = kmalloc(mem_size, sk->sk_allocation); + aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv); + mem = kmalloc(aead_size + struct_size(dctx, sg, n_sgin + n_sgout), + sk->sk_allocation); if (!mem) return -ENOMEM; /* Segment the allocated memory */ aead_req = (struct aead_request *)mem; - sgin = (struct scatterlist *)(mem + aead_size); - sgout = sgin + n_sgin; - aad = (u8 *)(sgout + n_sgout); - iv = aad + TLS_MAX_AAD_SIZE; - tail = iv + MAX_IV_SIZE; + dctx = (struct tls_decrypt_ctx *)(mem + aead_size); + sgin = &dctx->sg[0]; + sgout = &dctx->sg[n_sgin]; /* For CCM based ciphers, first byte of nonce+iv is a constant */ switch (prot->cipher_type) { case TLS_CIPHER_AES_CCM_128: - iv[0] = TLS_AES_CCM_IV_B0_BYTE; + dctx->iv[0] = TLS_AES_CCM_IV_B0_BYTE; iv_offset = 1; break; case TLS_CIPHER_SM4_CCM: - iv[0] = TLS_SM4_CCM_IV_B0_BYTE; + dctx->iv[0] = TLS_SM4_CCM_IV_B0_BYTE; iv_offset = 1; break; } @@ -1485,28 +1485,28 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, /* Prepare IV */ if (prot->version == TLS_1_3_VERSION || prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) { - memcpy(iv + iv_offset, tls_ctx->rx.iv, + memcpy(&dctx->iv[iv_offset], tls_ctx->rx.iv, prot->iv_size + prot->salt_size); } else { err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE, - iv + iv_offset + prot->salt_size, + &dctx->iv[iv_offset] + prot->salt_size, prot->iv_size); if (err < 0) { kfree(mem); return err; } - memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size); + memcpy(&dctx->iv[iv_offset], tls_ctx->rx.iv, prot->salt_size); } - xor_iv_with_seq(prot, iv + iv_offset, tls_ctx->rx.rec_seq); + xor_iv_with_seq(prot, &dctx->iv[iv_offset], tls_ctx->rx.rec_seq); /* Prepare AAD */ - tls_make_aad(aad, rxm->full_len - prot->overhead_size + + tls_make_aad(dctx->aad, rxm->full_len - prot->overhead_size + prot->tail_size, tls_ctx->rx.rec_seq, tlm->control, prot); /* Prepare sgin */ sg_init_table(sgin, n_sgin); - sg_set_buf(&sgin[0], aad, prot->aad_size); + sg_set_buf(&sgin[0], dctx->aad, prot->aad_size); err = skb_to_sgvec(skb, &sgin[1], rxm->offset + prot->prepend_size, rxm->full_len - prot->prepend_size); @@ -1518,7 +1518,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, if (n_sgout) { if (out_iov) { sg_init_table(sgout, n_sgout); - sg_set_buf(&sgout[0], aad, prot->aad_size); + sg_set_buf(&sgout[0], dctx->aad, prot->aad_size); err = tls_setup_from_iter(out_iov, data_len, &pages, &sgout[1], @@ -1528,7 +1528,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, if (prot->tail_size) { sg_unmark_end(&sgout[pages]); - sg_set_buf(&sgout[pages + 1], tail, + sg_set_buf(&sgout[pages + 1], &dctx->tail, prot->tail_size); sg_mark_end(&sgout[pages + 1]); } @@ -1545,13 +1545,13 @@ fallback_to_reg_recv: } /* Prepare and submit AEAD request */ - err = tls_do_decryption(sk, skb, sgin, sgout, iv, + err = tls_do_decryption(sk, skb, sgin, sgout, dctx->iv, data_len + prot->tail_size, aead_req, darg); if (darg->async) return 0; if (prot->tail_size) - darg->tail = *tail; + darg->tail = dctx->tail; /* Release the pages in case iov was mapped to pages */ for (; pages > 0; pages--) -- cgit v1.2.3