net/mlx5e: TLS, add Innova TLS rx data path

Implement the TLS rx offload data path according to the
requirements of the TLS generic NIC offload infrastructure.

Special metadata ethertype is used to pass information to
the hardware.

When hardware loses synchronization a special resync request
metadata message is used to request resync.
Signed-off-by: NBoris Pismenny <borisp@mellanox.com>
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls_rxtx.c

@@ -33,6 +33,12 @@
 
 #include "en_accel/tls.h"
 #include "en_accel/tls_rxtx.h"
+#include <net/inet6_hashtables.h>
+#include <linux/ipv6.h>
+
+#define SYNDROM_DECRYPTED  0x30
+#define SYNDROM_RESYNC_REQUEST 0x31
+#define SYNDROM_AUTH_FAILED 0x32
 
 #define SYNDROME_OFFLOAD_REQUIRED 32
 #define SYNDROME_SYNC 33
@@ -44,10 +50,26 @@ struct sync_info {
 	skb_frag_t frags[MAX_SKB_FRAGS];
 };
 
-struct mlx5e_tls_metadata {
+struct recv_metadata_content {
+	u8 syndrome;
+	u8 reserved;
+	__be32 sync_seq;
+} __packed;
+
+struct send_metadata_content {
 	/* One byte of syndrome followed by 3 bytes of swid */
 	__be32 syndrome_swid;
 	__be16 first_seq;
+} __packed;
+
+struct mlx5e_tls_metadata {
+	union {
+		/* from fpga to host */
+		struct recv_metadata_content recv;
+		/* from host to fpga */
+		struct send_metadata_content send;
+		unsigned char raw[6];
+	} __packed content;
 	/* packet type ID field	*/
 	__be16 ethertype;
 } __packed;
@@ -68,7 +90,8 @@ static int mlx5e_tls_add_metadata(struct sk_buff *skb, __be32 swid)
 		2 * ETH_ALEN);
 
 	eth->h_proto = cpu_to_be16(MLX5E_METADATA_ETHER_TYPE);
-	pet->syndrome_swid = htonl(SYNDROME_OFFLOAD_REQUIRED << 24) | swid;
+	pet->content.send.syndrome_swid =
+		htonl(SYNDROME_OFFLOAD_REQUIRED << 24) | swid;
 
 	return 0;
 }
@@ -149,7 +172,7 @@ static void mlx5e_tls_complete_sync_skb(struct sk_buff *skb,
 
 	pet = (struct mlx5e_tls_metadata *)(nskb->data + sizeof(struct ethhdr));
 	memcpy(pet, &syndrome, sizeof(syndrome));
-	pet->first_seq = htons(tcp_seq);
+	pet->content.send.first_seq = htons(tcp_seq);
 
 	/* MLX5 devices don't care about the checksum partial start, offset
 	 * and pseudo header
@@ -276,3 +299,86 @@ struct sk_buff *mlx5e_tls_handle_tx_skb(struct net_device *netdev,
 out:
 	return skb;
 }
+
+static int tls_update_resync_sn(struct net_device *netdev,
+				struct sk_buff *skb,
+				struct mlx5e_tls_metadata *mdata)
+{
+	struct sock *sk = NULL;
+	struct iphdr *iph;
+	struct tcphdr *th;
+	__be32 seq;
+
+	if (mdata->ethertype != htons(ETH_P_IP))
+		return -EINVAL;
+
+	iph = (struct iphdr *)(mdata + 1);
+
+	th = ((void *)iph) + iph->ihl * 4;
+
+	if (iph->version == 4) {
+		sk = inet_lookup_established(dev_net(netdev), &tcp_hashinfo,
+					     iph->saddr, th->source, iph->daddr,
+					     th->dest, netdev->ifindex);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else {
+		struct ipv6hdr *ipv6h = (struct ipv6hdr *)iph;
+
+		sk = __inet6_lookup_established(dev_net(netdev), &tcp_hashinfo,
+						&ipv6h->saddr, th->source,
+						&ipv6h->daddr, th->dest,
+						netdev->ifindex, 0);
+#endif
+	}
+	if (!sk || sk->sk_state == TCP_TIME_WAIT)
+		goto out;
+
+	skb->sk = sk;
+	skb->destructor = sock_edemux;
+
+	memcpy(&seq, &mdata->content.recv.sync_seq, sizeof(seq));
+	tls_offload_rx_resync_request(sk, seq);
+out:
+	return 0;
+}
+
+void mlx5e_tls_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
+			     u32 *cqe_bcnt)
+{
+	struct mlx5e_tls_metadata *mdata;
+	struct ethhdr *old_eth;
+	struct ethhdr *new_eth;
+	__be16 *ethtype;
+
+	/* Detect inline metadata */
+	if (skb->len < ETH_HLEN + MLX5E_METADATA_ETHER_LEN)
+		return;
+	ethtype = (__be16 *)(skb->data + ETH_ALEN * 2);
+	if (*ethtype != cpu_to_be16(MLX5E_METADATA_ETHER_TYPE))
+		return;
+
+	/* Use the metadata */
+	mdata = (struct mlx5e_tls_metadata *)(skb->data + ETH_HLEN);
+	switch (mdata->content.recv.syndrome) {
+	case SYNDROM_DECRYPTED:
+		skb->decrypted = 1;
+		break;
+	case SYNDROM_RESYNC_REQUEST:
+		tls_update_resync_sn(netdev, skb, mdata);
+		break;
+	case SYNDROM_AUTH_FAILED:
+		/* Authentication failure will be observed and verified by kTLS */
+		break;
+	default:
+		/* Bypass the metadata header to others */
+		return;
+	}
+
+	/* Remove the metadata from the buffer */
+	old_eth = (struct ethhdr *)skb->data;
+	new_eth = (struct ethhdr *)(skb->data + MLX5E_METADATA_ETHER_LEN);
+	memmove(new_eth, old_eth, 2 * ETH_ALEN);
+	/* Ethertype is already in its new place */
+	skb_pull_inline(skb, MLX5E_METADATA_ETHER_LEN);
+	*cqe_bcnt -= MLX5E_METADATA_ETHER_LEN;
+}

drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls_rxtx.h

@@ -45,6 +45,9 @@ struct sk_buff *mlx5e_tls_handle_tx_skb(struct net_device *netdev,
 					struct mlx5e_tx_wqe **wqe,
 					u16 *pi);
 
+void mlx5e_tls_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
+			     u32 *cqe_bcnt);
+
 #endif /* CONFIG_MLX5_EN_TLS */
 
 #endif /* __MLX5E_TLS_RXTX_H__ */

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

@@ -44,6 +44,7 @@
 #include "en_rep.h"
 #include "ipoib/ipoib.h"
 #include "en_accel/ipsec_rxtx.h"
+#include "en_accel/tls_rxtx.h"
 #include "lib/clock.h"
 
 static inline bool mlx5e_rx_hw_stamp(struct hwtstamp_config *config)
@@ -797,6 +798,11 @@ static inline void mlx5e_build_rx_skb(struct mlx5_cqe64 *cqe,
 	struct net_device *netdev = rq->netdev;
 
 	skb->mac_len = ETH_HLEN;
+
+#ifdef CONFIG_MLX5_EN_TLS
+	mlx5e_tls_handle_rx_skb(netdev, skb, &cqe_bcnt);
+#endif
+
 	if (lro_num_seg > 1) {
 		mlx5e_lro_update_hdr(skb, cqe, cqe_bcnt);
 		skb_shinfo(skb)->gso_size = DIV_ROUND_UP(cqe_bcnt, lro_num_seg);