4 files changed, 157 insertions, 14 deletions

diff --git a/include/linux/if_pppol2tp.h b/include/linux/if_pppol2tp.h
index 23cefa1111bf..b4775418d525 100644
--- a/include/linux/if_pppol2tp.h
+++ b/include/linux/if_pppol2tp.h
@@ -19,10 +19,11 @@
 
 #ifdef __KERNEL__
 #include <linux/in.h>
+#include <linux/in6.h>
 #endif
 
 /* Structure used to connect() the socket to a particular tunnel UDP
- * socket.
+ * socket over IPv4.
  */
 struct pppol2tp_addr {
         __kernel_pid_t  pid;            /* pid that owns the fd.
@@ -35,6 +36,20 @@ struct pppol2tp_addr {
         __u16 d_tunnel, d_session;      /* For sending outgoing packets */
 };
 
+/* Structure used to connect() the socket to a particular tunnel UDP
+ * socket over IPv6.
+ */
+struct pppol2tpin6_addr {
+        __kernel_pid_t  pid;            /* pid that owns the fd.
+                                         * 0 => current */
+        int     fd;                     /* FD of UDP socket to use */
+
+        __u16 s_tunnel, s_session;      /* For matching incoming packets */
+        __u16 d_tunnel, d_session;      /* For sending outgoing packets */
+
+        struct sockaddr_in6 addr;       /* IP address and port to send to */
+};
+
 /* The L2TPv3 protocol changes tunnel and session ids from 16 to 32
  * bits. So we need a different sockaddr structure.
  */
@@ -49,6 +64,17 @@ struct pppol2tpv3_addr {
         __u32 d_tunnel, d_session;      /* For sending outgoing packets */
 };
 
+struct pppol2tpv3in6_addr {
+        __kernel_pid_t  pid;            /* pid that owns the fd.
+                                         * 0 => current */
+        int     fd;                     /* FD of UDP or IP socket to use */
+
+        __u32 s_tunnel, s_session;      /* For matching incoming packets */
+        __u32 d_tunnel, d_session;      /* For sending outgoing packets */
+
+        struct sockaddr_in6 addr;       /* IP address and port to send to */
+};
+
 /* Socket options:
  * DEBUG        - bitmask of debug message categories
  * SENDSEQ      - 0 => don't send packets with sequence numbers
diff --git a/include/linux/if_pppox.h b/include/linux/if_pppox.h
index b5f927f59f26..6720d57cc1ea 100644
--- a/include/linux/if_pppox.h
+++ b/include/linux/if_pppox.h
@@ -83,6 +83,12 @@ struct sockaddr_pppol2tp {
         struct pppol2tp_addr pppol2tp;
 } __attribute__((packed));
 
+struct sockaddr_pppol2tpin6 {
+        __kernel_sa_family_t sa_family; /* address family, AF_PPPOX */
+        unsigned int    sa_protocol;    /* protocol identifier */
+        struct pppol2tpin6_addr pppol2tp;
+} __attribute__((packed));
+
 /* The L2TPv3 protocol changes tunnel and session ids from 16 to 32
  * bits. So we need a different sockaddr structure.
  */
@@ -92,6 +98,12 @@ struct sockaddr_pppol2tpv3 {
         struct pppol2tpv3_addr pppol2tp;
 } __attribute__((packed));
 
+struct sockaddr_pppol2tpv3in6 {
+        __kernel_sa_family_t sa_family; /* address family, AF_PPPOX */
+        unsigned int    sa_protocol;    /* protocol identifier */
+        struct pppol2tpv3in6_addr pppol2tp;
+} __attribute__((packed));
+
 /*********************************************************************
  *
  * ioctl interface for defining forwarding of connections
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index f6732b6c758b..e91d55924d94 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -53,6 +53,9 @@
 #include <net/inet_common.h>
 #include <net/xfrm.h>
 #include <net/protocol.h>
+#include <net/inet6_connection_sock.h>
+#include <net/inet_ecn.h>
+#include <net/ip6_route.h>
 
 #include <asm/byteorder.h>
 #include <linux/atomic.h>
@@ -446,21 +449,43 @@ static inline int l2tp_verify_udp_checksum(struct sock *sk,
 {
         struct udphdr *uh = udp_hdr(skb);
         u16 ulen = ntohs(uh->len);
-        struct inet_sock *inet;
         __wsum psum;
 
-        if (sk->sk_no_check || skb_csum_unnecessary(skb) || !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)))
+        if (sk->sk_no_check || skb_csum_unnecessary(skb))
                 return 0;
 
-        skb->csum = psum;
+#if IS_ENABLED(CONFIG_IPV6)
+        if (sk->sk_family == PF_INET6) {
+                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);
 }
@@ -988,7 +1013,12 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
 
         /* Queue the packet to IP for output */
         skb->local_df = 1;
-        error = ip_queue_xmit(skb, fl);
+#if IS_ENABLED(CONFIG_IPV6)
+        if (skb->sk->sk_family == PF_INET6)
+                error = inet6_csk_xmit(skb, NULL);
+        else
+#endif
+                error = ip_queue_xmit(skb, fl);
 
         /* Update stats */
         if (error >= 0) {
@@ -1021,6 +1051,31 @@ static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
         skb->destructor = l2tp_sock_wfree;
 }
 
+#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, &np->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, &np->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.
  */
@@ -1089,6 +1144,11 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
                 uh->check = 0;
 
                 /* Calculate UDP checksum if configured to do so */
+#if IS_ENABLED(CONFIG_IPV6)
+                if (sk->sk_family == PF_INET6)
+                        l2tp_xmit_ipv6_csum(sk, skb, 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) &&
@@ -1424,6 +1484,11 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
                 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
                 udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP;
                 udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv;
+#if IS_ENABLED(CONFIG_IPV6)
+                if (sk->sk_family == PF_INET6)
+                        udpv6_encap_enable();
+                else
+#endif
                 udp_encap_enable();
         }
 
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 1addd9f3f40a..27b9dec9d254 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -916,7 +916,7 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
         }
 
         inet = inet_sk(tunnel->sock);
-        if (tunnel->version == 2) {
+        if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
                 struct sockaddr_pppol2tp sp;
                 len = sizeof(sp);
                 memset(&sp, 0, len);
@@ -932,6 +932,46 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
                 sp.pppol2tp.addr.sin_port = inet->inet_dport;
                 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
                 memcpy(uaddr, &sp, len);
+#if IS_ENABLED(CONFIG_IPV6)
+        } else if ((tunnel->version == 2) &&
+                   (tunnel->sock->sk_family == AF_INET6)) {
+                struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
+                struct sockaddr_pppol2tpin6 sp;
+                len = sizeof(sp);
+                memset(&sp, 0, len);
+                sp.sa_family    = AF_PPPOX;
+                sp.sa_protocol  = PX_PROTO_OL2TP;
+                sp.pppol2tp.fd  = tunnel->fd;
+                sp.pppol2tp.pid = pls->owner;
+                sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
+                sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
+                sp.pppol2tp.s_session = session->session_id;
+                sp.pppol2tp.d_session = session->peer_session_id;
+                sp.pppol2tp.addr.sin6_family = AF_INET6;
+                sp.pppol2tp.addr.sin6_port = inet->inet_dport;
+                memcpy(&sp.pppol2tp.addr.sin6_addr, &np->daddr,
+                       sizeof(np->daddr));
+                memcpy(uaddr, &sp, len);
+        } else if ((tunnel->version == 3) &&
+                   (tunnel->sock->sk_family == AF_INET6)) {
+                struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
+                struct sockaddr_pppol2tpv3in6 sp;
+                len = sizeof(sp);
+                memset(&sp, 0, len);
+                sp.sa_family    = AF_PPPOX;
+                sp.sa_protocol  = PX_PROTO_OL2TP;
+                sp.pppol2tp.fd  = tunnel->fd;
+                sp.pppol2tp.pid = pls->owner;
+                sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
+                sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
+                sp.pppol2tp.s_session = session->session_id;
+                sp.pppol2tp.d_session = session->peer_session_id;
+                sp.pppol2tp.addr.sin6_family = AF_INET6;
+                sp.pppol2tp.addr.sin6_port = inet->inet_dport;
+                memcpy(&sp.pppol2tp.addr.sin6_addr, &np->daddr,
+                       sizeof(np->daddr));
+                memcpy(uaddr, &sp, len);
+#endif
         } else if (tunnel->version == 3) {
                 struct sockaddr_pppol2tpv3 sp;
                 len = sizeof(sp);