1 files changed, 13 insertions, 105 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index a4e37d7158dc..bea259043205 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -495,52 +495,6 @@ out:
         spin_unlock_bh(&session->reorder_q.lock);
 }
 
-static inline int l2tp_verify_udp_checksum(struct sock *sk,
-                                           struct sk_buff *skb)
-{
-        struct udphdr *uh = udp_hdr(skb);
-        u16 ulen = ntohs(uh->len);
-        __wsum psum;
-
-        if (sk->sk_no_check || skb_csum_unnecessary(skb))
-                return 0;
-
-#if IS_ENABLED(CONFIG_IPV6)
-        if (sk->sk_family == PF_INET6 && !l2tp_tunnel(sk)->v4mapped) {
-                if (!uh->check) {
-                        LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n");
-                        return 1;
-                }
-                if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
-                    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-                                     &ipv6_hdr(skb)->daddr, ulen,
-                                     IPPROTO_UDP, skb->csum)) {
-                        skb->ip_summed = CHECKSUM_UNNECESSARY;
-                        return 0;
-                }
-                skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-                                                         &ipv6_hdr(skb)->daddr,
-                                                         skb->len, IPPROTO_UDP,
-                                                         0));
-        } else
-#endif
-        {
-                struct inet_sock *inet;
-                if (!uh->check)
-                        return 0;
-                inet = inet_sk(sk);
-                psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr,
-                                          ulen, IPPROTO_UDP, 0);
-
-                if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
-                    !csum_fold(csum_add(psum, skb->csum)))
-                        return 0;
-                skb->csum = psum;
-        }
-
-        return __skb_checksum_complete(skb);
-}
-
 static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr)
 {
         u32 nws;
@@ -895,8 +849,7 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
         u16 version;
         int length;
 
-        if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb))
-                goto discard_bad_csum;
+        /* UDP has verifed checksum */
 
         /* UDP always verifies the packet length. */
         __skb_pull(skb, sizeof(struct udphdr));
@@ -979,14 +932,6 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 
         return 0;
 
-discard_bad_csum:
-        LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name);
-        UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0);
-        atomic_long_inc(&tunnel->stats.rx_errors);
-        kfree_skb(skb);
-
-        return 0;
-
 error:
         /* Put UDP header back */
         __skb_push(skb, sizeof(struct udphdr));
@@ -1128,7 +1073,7 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
         }
 
         /* Queue the packet to IP for output */
-        skb->local_df = 1;
+        skb->ignore_df = 1;
 #if IS_ENABLED(CONFIG_IPV6)
         if (tunnel->sock->sk_family == PF_INET6 && !tunnel->v4mapped)
                 error = inet6_csk_xmit(tunnel->sock, skb, NULL);
@@ -1150,31 +1095,6 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
         return 0;
 }
 
-#if IS_ENABLED(CONFIG_IPV6)
-static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb,
-                                int udp_len)
-{
-        struct ipv6_pinfo *np = inet6_sk(sk);
-        struct udphdr *uh = udp_hdr(skb);
-
-        if (!skb_dst(skb) || !skb_dst(skb)->dev ||
-            !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
-                __wsum csum = skb_checksum(skb, 0, udp_len, 0);
-                skb->ip_summed = CHECKSUM_UNNECESSARY;
-                uh->check = csum_ipv6_magic(&np->saddr, &sk->sk_v6_daddr, udp_len,
-                                            IPPROTO_UDP, csum);
-                if (uh->check == 0)
-                        uh->check = CSUM_MANGLED_0;
-        } else {
-                skb->ip_summed = CHECKSUM_PARTIAL;
-                skb->csum_start = skb_transport_header(skb) - skb->head;
-                skb->csum_offset = offsetof(struct udphdr, check);
-                uh->check = ~csum_ipv6_magic(&np->saddr, &sk->sk_v6_daddr,
-                                             udp_len, IPPROTO_UDP, 0);
-        }
-}
-#endif
-
 /* If caller requires the skb to have a ppp header, the header must be
  * inserted in the skb data before calling this function.
  */
@@ -1186,7 +1106,6 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
         struct flowi *fl;
         struct udphdr *uh;
         struct inet_sock *inet;
-        __wsum csum;
         int headroom;
         int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
         int udp_len;
@@ -1235,33 +1154,17 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
                 uh->dest = inet->inet_dport;
                 udp_len = uhlen + hdr_len + data_len;
                 uh->len = htons(udp_len);
-                uh->check = 0;
 
                 /* Calculate UDP checksum if configured to do so */
 #if IS_ENABLED(CONFIG_IPV6)
                 if (sk->sk_family == PF_INET6 && !tunnel->v4mapped)
-                        l2tp_xmit_ipv6_csum(sk, skb, udp_len);
+                        udp6_set_csum(udp_get_no_check6_tx(sk),
+                                      skb, &inet6_sk(sk)->saddr,
+                                      &sk->sk_v6_daddr, udp_len);
                 else
 #endif
-                if (sk->sk_no_check == UDP_CSUM_NOXMIT)
-                        skb->ip_summed = CHECKSUM_NONE;
-                else if ((skb_dst(skb) && skb_dst(skb)->dev) &&
-                         (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) {
-                        skb->ip_summed = CHECKSUM_COMPLETE;
-                        csum = skb_checksum(skb, 0, udp_len, 0);
-                        uh->check = csum_tcpudp_magic(inet->inet_saddr,
-                                                      inet->inet_daddr,
-                                                      udp_len, IPPROTO_UDP, csum);
-                        if (uh->check == 0)
-                                uh->check = CSUM_MANGLED_0;
-                } else {
-                        skb->ip_summed = CHECKSUM_PARTIAL;
-                        skb->csum_start = skb_transport_header(skb) - skb->head;
-                        skb->csum_offset = offsetof(struct udphdr, check);
-                        uh->check = ~csum_tcpudp_magic(inet->inet_saddr,
-                                                       inet->inet_daddr,
-                                                       udp_len, IPPROTO_UDP, 0);
-                }
+                udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr,
+                             inet->inet_daddr, udp_len);
                 break;
 
         case L2TP_ENCAPTYPE_IP:
@@ -1490,6 +1393,11 @@ static int l2tp_tunnel_sock_create(struct net *net,
                                              sizeof(udp6_addr), 0);
                         if (err < 0)
                                 goto out;
+
+                        if (cfg->udp6_zero_tx_checksums)
+                                udp_set_no_check6_tx(sock->sk, true);
+                        if (cfg->udp6_zero_rx_checksums)
+                                udp_set_no_check6_rx(sock->sk, true);
                 } else
 #endif
                 {
@@ -1518,7 +1426,7 @@ static int l2tp_tunnel_sock_create(struct net *net,
                 }
 
                 if (!cfg->use_udp_checksums)
-                        sock->sk->sk_no_check = UDP_CSUM_NOXMIT;
+                        sock->sk->sk_no_check_tx = 1;
 
                 break;