sctp: do not check port in sctp_inet6_cmp_addr

pf->cmp_addr() is called before binding a v6 address to the sock. It
should not check ports, like in sctp_inet_cmp_addr.

But sctp_inet6_cmp_addr checks the addr by invoking af(6)->cmp_addr,
sctp_v6_cmp_addr where it also compares the ports.

This would cause that setsockopt(SCTP_SOCKOPT_BINDX_ADD) could bind
multiple duplicated IPv6 addresses after Commit 40b4f0fd74 ("sctp:
lack the check for ports in sctp_v6_cmp_addr").

This patch is to remove af->cmp_addr called in sctp_inet6_cmp_addr,
but do the proper check for both v6 addrs and v4mapped addrs.

v1->v2:
  - define __sctp_v6_cmp_addr to do the common address comparison
    used for both pf and af v6 cmp_addr.

Fixes: 40b4f0fd74 ("sctp: lack the check for ports in sctp_v6_cmp_addr")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2018-04-12 14:24:31 +08:00 committed by David S. Miller
parent 837708a893
commit 1071ec9d45

View File

@ -556,44 +556,47 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
addr->v6.sin6_scope_id = 0;
}
static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
const union sctp_addr *addr2)
{
if (addr1->sa.sa_family != addr2->sa.sa_family) {
if (addr1->sa.sa_family == AF_INET &&
addr2->sa.sa_family == AF_INET6 &&
ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
addr2->v6.sin6_addr.s6_addr32[3] ==
addr1->v4.sin_addr.s_addr)
return 1;
if (addr2->sa.sa_family == AF_INET &&
addr1->sa.sa_family == AF_INET6 &&
ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
addr1->v6.sin6_addr.s6_addr32[3] ==
addr2->v4.sin_addr.s_addr)
return 1;
return 0;
}
if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
return 0;
/* If this is a linklocal address, compare the scope_id. */
if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
return 0;
return 1;
}
/* Compare addresses exactly.
* v4-mapped-v6 is also in consideration.
*/
static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
const union sctp_addr *addr2)
{
if (addr1->sa.sa_family != addr2->sa.sa_family) {
if (addr1->sa.sa_family == AF_INET &&
addr2->sa.sa_family == AF_INET6 &&
ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
if (addr2->v6.sin6_port == addr1->v4.sin_port &&
addr2->v6.sin6_addr.s6_addr32[3] ==
addr1->v4.sin_addr.s_addr)
return 1;
}
if (addr2->sa.sa_family == AF_INET &&
addr1->sa.sa_family == AF_INET6 &&
ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
if (addr1->v6.sin6_port == addr2->v4.sin_port &&
addr1->v6.sin6_addr.s6_addr32[3] ==
addr2->v4.sin_addr.s_addr)
return 1;
}
return 0;
}
if (addr1->v6.sin6_port != addr2->v6.sin6_port)
return 0;
if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
return 0;
/* If this is a linklocal address, compare the scope_id. */
if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
(addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
return 0;
}
}
return 1;
return __sctp_v6_cmp_addr(addr1, addr2) &&
addr1->v6.sin6_port == addr2->v6.sin6_port;
}
/* Initialize addr struct to INADDR_ANY. */
@ -875,8 +878,8 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
const union sctp_addr *addr2,
struct sctp_sock *opt)
{
struct sctp_af *af1, *af2;
struct sock *sk = sctp_opt2sk(opt);
struct sctp_af *af1, *af2;
af1 = sctp_get_af_specific(addr1->sa.sa_family);
af2 = sctp_get_af_specific(addr2->sa.sa_family);
@ -892,10 +895,7 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
return 1;
if (addr1->sa.sa_family != addr2->sa.sa_family)
return 0;
return af1->cmp_addr(addr1, addr2);
return __sctp_v6_cmp_addr(addr1, addr2);
}
/* Verify that the provided sockaddr looks bindable. Common verification,