openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
David S. Miller 2017-02-14 12:13:52 -05:00
parent fed06ee89b 052d2369d1
commit 144adc655f
4 changed files with 24 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
net/ipv6/datagram.c
View File

@ -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)) {

3
net/ipv6/ip6_output.c
View File

@ -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;

11
net/ipv6/tcp_ipv6.c
View File

@ -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;

4
net/ipv6/udp.c
View File

@ -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;