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authorDmitry Safonov <dima@arista.com>2023-10-23 22:21:56 +0300
committerDavid S. Miller <davem@davemloft.net>2023-10-27 12:35:44 +0300
commit0aadc73995d08f6b0dc061c14a564ffa46f5914e (patch)
treed104c5c1772bec3362f2aababc1b5a79ec3e44bc /net/ipv6
parent4954f17ddefc51d218625dcdfaf422a253dad3fa (diff)
downloadlinux-0aadc73995d08f6b0dc061c14a564ffa46f5914e.tar.xz
net/tcp: Prevent TCP-MD5 with TCP-AO being set
Be as conservative as possible: if there is TCP-MD5 key for a given peer regardless of L3 interface - don't allow setting TCP-AO key for the same peer. According to RFC5925, TCP-AO is supposed to replace TCP-MD5 and there can't be any switch between both on any connected tuple. Later it can be relaxed, if there's a use, but in the beginning restrict any intersection. Note: it's still should be possible to set both TCP-MD5 and TCP-AO keys on a listening socket for *different* peers. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/tcp_ao.c17
-rw-r--r--net/ipv6/tcp_ipv6.c26
2 files changed, 39 insertions, 4 deletions
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 049ddbabe049..0640acaee67b 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -12,6 +12,23 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+static struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int sndid, int rcvid)
+{
+ return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)addr, AF_INET6,
+ sndid, rcvid);
+}
+
+struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
+ struct sock *addr_sk,
+ int sndid, int rcvid)
+{
+ struct in6_addr *addr = &addr_sk->sk_v6_daddr;
+
+ return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
+}
+
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen)
{
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 30bd17d03239..70a3842f47fa 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -600,6 +600,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
{
struct tcp_md5sig cmd;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
+ union tcp_ao_addr *addr;
int l3index = 0;
u8 prefixlen;
u8 flags;
@@ -654,13 +655,28 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
return -EINVAL;
- if (ipv6_addr_v4mapped(&sin6->sin6_addr))
- return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
+ addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3];
+
+ /* Don't allow keys for peers that have a matching TCP-AO key.
+ * See the comment in tcp_ao_add_cmd()
+ */
+ if (tcp_ao_required(sk, addr, AF_INET))
+ return -EKEYREJECTED;
+ return tcp_md5_do_add(sk, addr,
AF_INET, prefixlen, l3index, flags,
cmd.tcpm_key, cmd.tcpm_keylen);
+ }
+
+ addr = (union tcp_md5_addr *)&sin6->sin6_addr;
+
+ /* Don't allow keys for peers that have a matching TCP-AO key.
+ * See the comment in tcp_ao_add_cmd()
+ */
+ if (tcp_ao_required(sk, addr, AF_INET6))
+ return -EKEYREJECTED;
- return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
- AF_INET6, prefixlen, l3index, flags,
+ return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
cmd.tcpm_key, cmd.tcpm_keylen);
}
@@ -1903,6 +1919,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
.md5_parse = tcp_v6_parse_md5_keys,
#endif
#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v6_ao_lookup,
.ao_parse = tcp_v6_parse_ao,
#endif
};
@@ -1934,6 +1951,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
.md5_parse = tcp_v6_parse_md5_keys,
#endif
#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v6_ao_lookup,
.ao_parse = tcp_v6_parse_ao,
#endif
};