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author | David S. Miller <davem@davemloft.net> | 2017-02-14 12:13:52 -0500 |
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committer | David S. Miller <davem@davemloft.net> | 2017-02-14 12:13:52 -0500 |
commit | 144adc655fac089d485ee66354d402b319cff6d2 (patch) | |
tree | 16f83a2393edec2827eac68eac1d1e739dcb862f | |
parent | fed06ee89b78d3af32e235e0e89ad0d946fcb95d (diff) | |
parent | 052d2369d1b479cdbbe020fdd6d057d3c342db74 (diff) | |
download | op-kernel-dev-144adc655fac089d485ee66354d402b319cff6d2.zip op-kernel-dev-144adc655fac089d485ee66354d402b319cff6d2.tar.gz |
Merge branch 'ipv6-v4mapped'
Jonathan T. Leighton says:
====================
IPv4-mapped on wire, :: dst address issue
Under some circumstances IPv6 datagrams are sent with IPv4-mapped IPv6
addresses as the source. Given an IPv6 socket bound to an IPv4-mapped
IPv6 address, and an IPv6 destination address, both TCP and UDP will
will send packets using the IPv4-mapped IPv6 address as the source. Per
RFC 6890 (Table 20), IPv4-mapped IPv6 source addresses are not allowed
in an IP datagram. The problem can be observed by attempting to
connect() either a TCP or UDP socket, or by using sendmsg() with a UDP
socket. The patch is intended to correct this issue for all socket
types.
linux follows the BSD convention that an IPv6 destination address
specified as in6addr_any is converted to the loopback address.
Currently, neither TCP nor UDP consider the possibility that the source
address is an IPv4-mapped IPv6 address, and assume that the appropriate
loopback address is ::1. The patch adds a check on whether or not the
source address is an IPv4-mapped IPv6 address and then sets the
destination address to either ::ffff:127.0.0.1 or ::1, as appropriate.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | net/ipv6/datagram.c | 14 | ||||
-rw-r--r-- | net/ipv6/ip6_output.c | 3 | ||||
-rw-r--r-- | net/ipv6/tcp_ipv6.c | 11 | ||||
-rw-r--r-- | net/ipv6/udp.c | 4 |
4 files changed, 24 insertions, 8 deletions
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c index a3eaafd..eec27f8 100644 --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -167,18 +167,22 @@ int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, if (np->sndflow) fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; - addr_type = ipv6_addr_type(&usin->sin6_addr); - - if (addr_type == IPV6_ADDR_ANY) { + if (ipv6_addr_any(&usin->sin6_addr)) { /* * connect to self */ - usin->sin6_addr.s6_addr[15] = 0x01; + if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) + ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), + &usin->sin6_addr); + else + usin->sin6_addr = in6addr_loopback; } + addr_type = ipv6_addr_type(&usin->sin6_addr); + daddr = &usin->sin6_addr; - if (addr_type == IPV6_ADDR_MAPPED) { + if (addr_type & IPV6_ADDR_MAPPED) { struct sockaddr_in sin; if (__ipv6_only_sock(sk)) { diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index b6a94ff..e164684 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1021,6 +1021,9 @@ static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, } } #endif + if (ipv6_addr_v4mapped(&fl6->saddr) && + !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) + return -EAFNOSUPPORT; return 0; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index eaad72c..4c60c6f 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -148,8 +148,13 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, * connect() to INADDR_ANY means loopback (BSD'ism). */ - if (ipv6_addr_any(&usin->sin6_addr)) - usin->sin6_addr.s6_addr[15] = 0x1; + if (ipv6_addr_any(&usin->sin6_addr)) { + if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) + ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), + &usin->sin6_addr); + else + usin->sin6_addr = in6addr_loopback; + } addr_type = ipv6_addr_type(&usin->sin6_addr); @@ -188,7 +193,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, * TCP over IPv4 */ - if (addr_type == IPV6_ADDR_MAPPED) { + if (addr_type & IPV6_ADDR_MAPPED) { u32 exthdrlen = icsk->icsk_ext_hdr_len; struct sockaddr_in sin; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 8990856..221825a 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1033,6 +1033,10 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; daddr = &sin6->sin6_addr; + if (ipv6_addr_any(daddr) && + ipv6_addr_v4mapped(&np->saddr)) + ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), + daddr); break; case AF_INET: goto do_udp_sendmsg; |