Add a flag field and address prefix length at the end of the tcp_md5sig
structure so users can configure an address prefix length along with a
key. Make sure shorter option values are still accepted in
tcp_v4_parse_md5_keys and tcp_v6_parse_md5_keys to maintain backward
compatibility.
Signed-off-by: Bob Gilligan <gilli...@arista.com>
Signed-off-by: Eric Mowat <mo...@arista.com>
Signed-off-by: Ivan Delalande <col...@arista.com>
---
include/uapi/linux/tcp.h | 8 ++++++++
net/ipv4/tcp_ipv4.c | 15 +++++++++++----
net/ipv6/tcp_ipv6.c | 24 +++++++++++++++++-------
3 files changed, 36 insertions(+), 11 deletions(-)
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 38a2b07afdff..440a8d983e4b 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -233,6 +233,12 @@ enum {
/* for TCP_MD5SIG socket option */
#define TCP_MD5SIG_MAXKEYLEN 80
+/* original struct stopped at tcpm_key and must still be considered valid */
+#define TCP_MD5SIG_LEGACY_LEN (offsetof(struct tcp_md5sig, tcpm_key) + \
+ TCP_MD5SIG_MAXKEYLEN)
+
+/* tcp_md5sig flags */
+#define TCP_MD5SIG_FLAG_PREFIX 1 /* address prefix length */
struct tcp_md5sig {
struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
@@ -240,6 +246,8 @@ struct tcp_md5sig {
__u16 tcpm_keylen; /* key length */
__u32 __tcpm_pad2; /* zero */
__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
+ __u8 tcpm_flags; /* flags */
+ __u8 tcpm_prefixlen; /* address prefix */
};
#endif /* _UAPI_LINUX_TCP_H */
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 51ca3bd5a8a3..96a56224b913 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1069,25 +1069,32 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char
__user *optval,
{
struct tcp_md5sig cmd;
struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
+ u8 prefixlen = 32;
- if (optlen < sizeof(cmd))
+ if (optlen < TCP_MD5SIG_LEGACY_LEN)
return -EINVAL;
- if (copy_from_user(&cmd, optval, sizeof(cmd)))
+ if (copy_from_user(&cmd, optval, min_t(size_t, sizeof(cmd), optlen)))
return -EFAULT;
if (sin->sin_family != AF_INET)
return -EINVAL;
+ if (optlen >= sizeof(cmd) && 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..aff909e19b3d 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -519,22 +519,32 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, char
__user *optval,
{
struct tcp_md5sig cmd;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
+ u8 prefixlen;
- if (optlen < sizeof(cmd))
+ if (optlen < TCP_MD5SIG_LEGACY_LEN)
return -EINVAL;
- if (copy_from_user(&cmd, optval, sizeof(cmd)))
+ if (copy_from_user(&cmd, optval, min_t(size_t, sizeof(cmd), optlen)))
return -EFAULT;
if (sin6->sin6_family != AF_INET6)
return -EINVAL;
+ if (optlen >= sizeof(cmd) && 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 +552,12 @@ 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
