Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752143AbdFPBHL (ORCPT ); Thu, 15 Jun 2017 21:07:11 -0400 Received: from prod-mx.aristanetworks.com ([162.210.130.12]:63724 "EHLO prod-mx.aristanetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751641AbdFPBHJ (ORCPT ); Thu, 15 Jun 2017 21:07:09 -0400 From: Ivan Delalande To: David Miller Cc: Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Ivan Delalande Subject: [PATCH v3 2/2] tcp: md5: add TCP_MD5SIG_EXT socket option to set a key address prefix Date: Thu, 15 Jun 2017 18:07:07 -0700 Message-Id: <20170616010707.27666-2-colona@arista.com> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170616010707.27666-1-colona@arista.com> References: <20170610021449.16091-1-colona@arista.com> <20170616010707.27666-1-colona@arista.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6274 Lines: 180 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 --- include/net/tcp.h | 1 + include/uapi/linux/tcp.h | 9 +++++++-- net/ipv4/tcp.c | 3 ++- net/ipv4/tcp_ipv4.c | 16 ++++++++++++---- net/ipv6/tcp_ipv6.c | 25 ++++++++++++++++++------- 5 files changed, 40 insertions(+), 14 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 2b68023ab095..575f95cb8275 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1802,6 +1802,7 @@ struct tcp_sock_af_ops { const struct sock *sk, const struct sk_buff *skb); int (*md5_parse)(struct sock *sk, + int optname, char __user *optval, int optlen); #endif diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index 38a2b07afdff..9870b7f08f4f 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -117,6 +117,7 @@ enum { #define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */ #define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */ #define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */ +#define TCP_MD5SIG_EXT 31 /* TCP MD5 Signature with extensions */ struct tcp_repair_opt { __u32 opt_code; @@ -234,11 +235,15 @@ enum { /* for TCP_MD5SIG socket option */ #define TCP_MD5SIG_MAXKEYLEN 80 +/* tcp_md5sig extension flags for TCP_MD5SIG_EXT */ +#define TCP_MD5SIG_FLAG_PREFIX 1 /* address prefix length */ + struct tcp_md5sig { struct __kernel_sockaddr_storage tcpm_addr; /* address associated */ - __u16 __tcpm_pad1; /* zero */ + __u8 tcpm_flags; /* extension flags */ + __u8 tcpm_prefixlen; /* address prefix */ __u16 tcpm_keylen; /* key length */ - __u32 __tcpm_pad2; /* zero */ + __u32 __tcpm_pad; /* zero */ __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ }; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 1e4c76d2b827..2a68221d2e55 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2666,8 +2666,9 @@ static int do_tcp_setsockopt(struct sock *sk, int level, #ifdef CONFIG_TCP_MD5SIG case TCP_MD5SIG: + case TCP_MD5SIG_EXT: /* Read the IP->Key mappings from userspace */ - err = tp->af_specific->md5_parse(sk, optval, optlen); + err = tp->af_specific->md5_parse(sk, optname, optval, optlen); break; #endif case TCP_USER_TIMEOUT: diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 51ca3bd5a8a3..81d6c16aecdc 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1064,11 +1064,12 @@ static void tcp_clear_md5_list(struct sock *sk) } } -static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, - int optlen) +static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, + char __user *optval, int optlen) { struct tcp_md5sig cmd; struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; + u8 prefixlen = 32; if (optlen < sizeof(cmd)) return -EINVAL; @@ -1079,15 +1080,22 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, if (sin->sin_family != AF_INET) return -EINVAL; + if (optname == TCP_MD5SIG_EXT && + cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { + prefixlen = cmd.tcpm_prefixlen; + if (prefixlen > 32) + return -EINVAL; + } + if (!cmd.tcpm_keylen) return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, - AF_INET, 32); + AF_INET, prefixlen); if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) return -EINVAL; return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, - AF_INET, 32, cmd.tcpm_key, cmd.tcpm_keylen, + AF_INET, prefixlen, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 5cf19dab60aa..ae36442786ec 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -514,11 +514,12 @@ 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; @@ -529,12 +530,22 @@ 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) @@ -542,12 +553,12 @@ 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, -- 2.13.1