4 files changed, 88 insertions, 10 deletions

diff --git a/include/linux/udp.h b/include/linux/udp.h
index e23d5024f42f..0a9c54e76305 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -132,6 +132,12 @@ static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
         }
 }
 
+static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
+{
+        return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) &&
+               skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4;
+}
+
 #define udp_portaddr_for_each_entry(__sk, list) \
         hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
 
diff --git a/include/net/udp.h b/include/net/udp.h
index a496e441645e..eccca2325ee6 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -417,17 +417,24 @@ static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,
 } while(0)
 
 #if IS_ENABLED(CONFIG_IPV6)
-#define __UDPX_INC_STATS(sk, field)                                     \
-do {                                                                    \
-        if ((sk)->sk_family == AF_INET)                                 \
-                __UDP_INC_STATS(sock_net(sk), field, 0);                \
-        else                                                            \
-                __UDP6_INC_STATS(sock_net(sk), field, 0);               \
-} while (0)
+#define __UDPX_MIB(sk, ipv4)                                            \
+({                                                                      \
+        ipv4 ? (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics : \
+                                 sock_net(sk)->mib.udp_statistics) :    \
+                (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_stats_in6 : \
+                                 sock_net(sk)->mib.udp_stats_in6);      \
+})
 #else
-#define __UDPX_INC_STATS(sk, field) __UDP_INC_STATS(sock_net(sk), field, 0)
+#define __UDPX_MIB(sk, ipv4)                                            \
+({                                                                      \
+        IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics :         \
+                         sock_net(sk)->mib.udp_statistics;              \
+})
 #endif
 
+#define __UDPX_INC_STATS(sk, field) \
+        __SNMP_INC_STATS(__UDPX_MIB(sk, (sk)->sk_family == AF_INET), field)
+
 #ifdef CONFIG_PROC_FS
 struct udp_seq_afinfo {
         sa_family_t                     family;
@@ -461,4 +468,26 @@ DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
 void udpv6_encap_enable(void);
 #endif
 
+static inline struct sk_buff *udp_rcv_segment(struct sock *sk,
+                                              struct sk_buff *skb, bool ipv4)
+{
+        struct sk_buff *segs;
+
+        /* the GSO CB lays after the UDP one, no need to save and restore any
+         * CB fragment
+         */
+        segs = __skb_gso_segment(skb, NETIF_F_SG, false);
+        if (unlikely(IS_ERR_OR_NULL(segs))) {
+                int segs_nr = skb_shinfo(skb)->gso_segs;
+
+                atomic_add(segs_nr, &sk->sk_drops);
+                SNMP_ADD_STATS(__UDPX_MIB(sk, ipv4), UDP_MIB_INERRORS, segs_nr);
+                kfree_skb(skb);
+                return NULL;
+        }
+
+        consume_skb(skb);
+        return segs;
+}
+
 #endif  /* _UDP_H */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index dddc6fe90f51..3488650b90ac 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1906,7 +1906,7 @@ EXPORT_SYMBOL(udp_encap_enable);
  * Note that in the success and error cases, the skb is assumed to
  * have either been requeued or freed.
  */
-static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 {
         struct udp_sock *up = udp_sk(sk);
         int is_udplite = IS_UDPLITE(sk);
@@ -2009,6 +2009,27 @@ drop:
         return -1;
 }
 
+static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+        struct sk_buff *next, *segs;
+        int ret;
+
+        if (likely(!udp_unexpected_gso(sk, skb)))
+                return udp_queue_rcv_one_skb(sk, skb);
+
+        BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_SGO_CB_OFFSET);
+        __skb_push(skb, -skb_mac_offset(skb));
+        segs = udp_rcv_segment(sk, skb, true);
+        for (skb = segs; skb; skb = next) {
+                next = skb->next;
+                __skb_pull(skb, skb_transport_offset(skb));
+                ret = udp_queue_rcv_one_skb(sk, skb);
+                if (ret > 0)
+                        ip_protocol_deliver_rcu(dev_net(skb->dev), skb, -ret);
+        }
+        return 0;
+}
+
 /* For TCP sockets, sk_rx_dst is protected by socket lock
  * For UDP, we use xchg() to guard against concurrent changes.
  */
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 4c79dc5329bc..c55698d19d68 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -554,7 +554,7 @@ void udpv6_encap_enable(void)
 }
 EXPORT_SYMBOL(udpv6_encap_enable);
 
-static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 {
         struct udp_sock *up = udp_sk(sk);
         int is_udplite = IS_UDPLITE(sk);
@@ -637,6 +637,28 @@ drop:
         return -1;
 }
 
+static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+        struct sk_buff *next, *segs;
+        int ret;
+
+        if (likely(!udp_unexpected_gso(sk, skb)))
+                return udpv6_queue_rcv_one_skb(sk, skb);
+
+        __skb_push(skb, -skb_mac_offset(skb));
+        segs = udp_rcv_segment(sk, skb, false);
+        for (skb = segs; skb; skb = next) {
+                next = skb->next;
+                __skb_pull(skb, skb_transport_offset(skb));
+
+                ret = udpv6_queue_rcv_one_skb(sk, skb);
+                if (ret > 0)
+                        ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
+                                                 true);
+        }
+        return 0;
+}
+
 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
                                    __be16 loc_port, const struct in6_addr *loc_addr,
                                    __be16 rmt_port, const struct in6_addr *rmt_addr,