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 <gilligan@arista.com>
Signed-off-by: Eric Mowat <mowat@arista.com>
Signed-off-by: Ivan Delalande <colona@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ivan Delalande 2017-06-15 18:07:07 -07:00 committed by David S. Miller
parent 6797318e62
commit 8917a777be
5 changed files with 41 additions and 15 deletions

View File

@ -1848,6 +1848,7 @@ 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

View File

@ -117,7 +117,8 @@ 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_ULP 31 /* Attach a ULP to a TCP connection */
#define TCP_ULP 31 /* Attach a ULP to a TCP connection */
#define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */
struct tcp_repair_opt {
__u32 opt_code;
@ -235,11 +236,15 @@ 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) */
};

View File

@ -2714,8 +2714,9 @@ 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:

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@ -1066,11 +1066,12 @@ 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;
@ -1081,15 +1082,22 @@ 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);
}

View File

@ -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,