From 8917a777be3ba566377be05117f71b93a5fd909d Mon Sep 17 00:00:00 2001 From: Ivan Delalande Date: Thu, 15 Jun 2017 18:07:07 -0700 Subject: tcp: md5: add TCP_MD5SIG_EXT socket option to set a key address prefix Replace first padding in the tcp_md5sig structure with a new flag field and address prefix length so it can be specified when configuring a new key for TCP MD5 signature. The tcpm_flags field will only be used if the socket option is TCP_MD5SIG_EXT to avoid breaking existing programs, and tcpm_prefixlen only when the TCP_MD5SIG_FLAG_PREFIX flag is set. Signed-off-by: Bob Gilligan Signed-off-by: Eric Mowat Signed-off-by: Ivan Delalande Signed-off-by: David S. Miller --- net/ipv6/tcp_ipv6.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) (limited to 'net/ipv6/tcp_ipv6.c') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 261689310408..68dc7472b44d 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -515,11 +515,12 @@ static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk, return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr); } -static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval, - int optlen) +static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, + char __user *optval, int optlen) { struct tcp_md5sig cmd; struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; + u8 prefixlen; if (optlen < sizeof(cmd)) return -EINVAL; @@ -530,12 +531,22 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval, if (sin6->sin6_family != AF_INET6) return -EINVAL; + if (optname == TCP_MD5SIG_EXT && + cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { + prefixlen = cmd.tcpm_prefixlen; + if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) && + prefixlen > 32)) + return -EINVAL; + } else { + prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128; + } + if (!cmd.tcpm_keylen) { if (ipv6_addr_v4mapped(&sin6->sin6_addr)) return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], - AF_INET, 32); + AF_INET, prefixlen); return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, - AF_INET6, 128); + AF_INET6, prefixlen); } if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) @@ -543,12 +554,12 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval, if (ipv6_addr_v4mapped(&sin6->sin6_addr)) return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], - AF_INET, 32, cmd.tcpm_key, + AF_INET, prefixlen, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr, - AF_INET6, 128, cmd.tcpm_key, cmd.tcpm_keylen, - GFP_KERNEL); + AF_INET6, prefixlen, cmd.tcpm_key, + cmd.tcpm_keylen, GFP_KERNEL); } static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp, -- cgit v1.2.3