tls: rx: device: keep the zero copy status with offload

The non-zero-copy path assumes a full skb with decrypted contents.
This means the device offload would have to CoW the data. Try
to keep the zero-copy status instead, copy the data to user space.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/tls/tls.h b/net/tls/tls.h
index 24bec1c..78c5d69 100644 (file)
--- a/net/tls/tls.h
+++ b/net/tls/tls.h
@@ -127,6 +127,7 @@ int tls_sw_fallback_init(struct sock *sk,
                         struct tls_offload_context_tx *offload_ctx,
                         struct tls_crypto_info *crypto_info);
 
+struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
 int tls_strp_msg_hold(struct sock *sk, struct sk_buff *skb,
                      struct sk_buff_head *dst);
 

diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c
index 9ccab79..40b1773 100644 (file)
--- a/net/tls/tls_strp.c
+++ b/net/tls/tls_strp.c
@@ -4,6 +4,15 @@
 
 #include "tls.h"
 
+struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx)
+{
+       struct sk_buff *skb;
+
+       skb = ctx->recv_pkt;
+       ctx->recv_pkt = NULL;
+       return skb;
+}
+
 int tls_strp_msg_hold(struct sock *sk, struct sk_buff *skb,
                      struct sk_buff_head *dst)
 {

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index fe38b49..bd44868 100644 (file)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1631,8 +1631,8 @@ tls_decrypt_sw(struct sock *sk, struct tls_context *tls_ctx,
 }
 
 static int
-tls_decrypt_device(struct sock *sk, struct tls_context *tls_ctx,
-                  struct tls_decrypt_arg *darg)
+tls_decrypt_device(struct sock *sk, struct msghdr *msg,
+                  struct tls_context *tls_ctx, struct tls_decrypt_arg *darg)
 {
        struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
        struct tls_prot_info *prot = &tls_ctx->prot_info;
@@ -1650,13 +1650,33 @@ tls_decrypt_device(struct sock *sk, struct tls_context *tls_ctx,
        if (pad < 0)
                return pad;
 
-       darg->zc = false;
        darg->async = false;
        darg->skb = tls_strp_msg(ctx);
-       ctx->recv_pkt = NULL;
+       /* ->zc downgrade check, in case TLS 1.3 gets here */
+       darg->zc &= !(prot->version == TLS_1_3_VERSION &&
+                     tls_msg(darg->skb)->control != TLS_RECORD_TYPE_DATA);
 
        rxm = strp_msg(darg->skb);
        rxm->full_len -= pad;
+
+       if (!darg->zc) {
+               /* Non-ZC case needs a real skb */
+               darg->skb = tls_strp_msg_detach(ctx);
+               if (!darg->skb)
+                       return -ENOMEM;
+       } else {
+               unsigned int off, len;
+
+               /* In ZC case nobody cares about the output skb.
+                * Just copy the data here. Note the skb is not fully trimmed.
+                */
+               off = rxm->offset + prot->prepend_size;
+               len = rxm->full_len - prot->overhead_size;
+
+               err = skb_copy_datagram_msg(darg->skb, off, msg, len);
+               if (err)
+                       return err;
+       }
        return 1;
 }
 
@@ -1668,7 +1688,7 @@ static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
        struct strp_msg *rxm;
        int err;
 
-       err = tls_decrypt_device(sk, tls_ctx, darg);
+       err = tls_decrypt_device(sk, msg, tls_ctx, darg);
        if (!err)
                err = tls_decrypt_sw(sk, tls_ctx, msg, darg);
        if (err < 0)