Signed-off-by: Gilberto Bertin <gilberto.ber...@gmail.com>
---
include/net/sock.h | 20 +++++++
include/uapi/asm-generic/socket.h | 1 +
net/core/sock.c | 111 ++++++++++++++++++++++++++++++++++++++
3 files changed, 132 insertions(+)
diff --git a/include/net/sock.h b/include/net/sock.h
index f5ea148..c115c48 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -109,6 +109,16 @@ typedef struct {
#endif
} socket_lock_t;
+struct ipv4_subnet {
+ __be32 net;
+ u_char plen;
+};
+
+struct ipv6_subnet {
+ struct in6_addr net;
+ u_char plen;
+};
+
struct sock;
struct proto;
struct net;
@@ -176,6 +186,13 @@ struct sock_common {
unsigned char skc_ipv6only:1;
unsigned char skc_net_refcnt:1;
int skc_bound_dev_if;
+
+ unsigned char skc_bind_to_subnet;
+ union {
+ struct ipv4_subnet skc_bind_subnet4;
+ struct ipv6_subnet skc_bind_subnet6;
+ };
+
union {
struct hlist_node skc_bind_node;
struct hlist_nulls_node skc_portaddr_node;
@@ -327,6 +344,9 @@ struct sock {
#define sk_state __sk_common.skc_state
#define sk_reuse __sk_common.skc_reuse
#define sk_reuseport __sk_common.skc_reuseport
+#define sk_bind_to_subnet __sk_common.skc_bind_to_subnet
+#define sk_bind_subnet4 __sk_common.skc_bind_subnet4
+#define sk_bind_subnet6 __sk_common.skc_bind_subnet6
#define sk_ipv6only __sk_common.skc_ipv6only
#define sk_net_refcnt __sk_common.skc_net_refcnt
#define sk_bound_dev_if __sk_common.skc_bound_dev_if
diff --git a/include/uapi/asm-generic/socket.h
b/include/uapi/asm-generic/socket.h
index fb8a416..b4bcac2 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -30,6 +30,7 @@
#define SO_SNDLOWAT 19
#define SO_RCVTIMEO 20
#define SO_SNDTIMEO 21
+#define SO_BINDTOSUBNET 22
#endif
/* Security levels - as per NRL IPv6 - don't actually do anything */
diff --git a/net/core/sock.c b/net/core/sock.c
index 6c1c8bc..7626153 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -571,6 +571,68 @@ out:
return ret;
}
+static int sock_setbindtosubnet(struct sock *sk, char __user *optval,
+ int optlen)
+{
+ int ret = -ENOPROTOOPT;
+
+ if (sk->sk_family == AF_INET) {
+ struct ipv4_subnet bind_subnet4;
+
+ ret = -EFAULT;
+ if (optlen != sizeof(struct ipv4_subnet))
+ goto out;
+
+ if (copy_from_user(&bind_subnet4, optval,
+ sizeof(struct ipv4_subnet)))
+ goto out;
+
+ ret = -EINVAL;
+ if (bind_subnet4.plen > 32)
+ goto out;
+
+ lock_sock(sk);
+
+ sk->sk_bind_to_subnet = 1;
+ sk->sk_bind_subnet4.net = bind_subnet4.net;
+ sk->sk_bind_subnet4.plen = bind_subnet4.plen;
+ sk_dst_reset(sk);
+
+ release_sock(sk);
+
+ ret = 0;
+ } else if (sk->sk_family == AF_INET6) {
+ struct ipv6_subnet bind_subnet6;
+
+ ret = -EFAULT;
+ if (optlen != sizeof(struct ipv6_subnet))
+ goto out;
+
+ if (copy_from_user(&bind_subnet6, optval,
+ sizeof(struct ipv6_subnet)))
+ goto out;
+
+ ret = -EINVAL;
+ if (bind_subnet6.plen > 128)
+ goto out;
+
+ lock_sock(sk);
+
+ sk->sk_bind_to_subnet = 1;
+ memcpy(&sk->sk_bind_subnet6.net, &bind_subnet6.net,
+ sizeof(struct in6_addr));
+ sk->sk_bind_subnet6.plen = bind_subnet6.plen;
+ sk_dst_reset(sk);
+
+ release_sock(sk);
+
+ ret = 0;
+ }
+
+out:
+ return ret;
+}
+
static int sock_getbindtodevice(struct sock *sk, char __user *optval,
int __user *optlen, int len)
{
@@ -611,6 +673,49 @@ out:
return ret;
}
+static int sock_getbindtosubnet(struct sock *sk, char __user *optval,
+ int __user *optlen, int len)
+{
+ int ret;
+
+ if (sk->sk_bind_to_subnet == 0) {
+ len = 0;
+ goto zero;
+ }
+
+ if (sk->sk_family == AF_INET) {
+ ret = -EINVAL;
+ if (len < sizeof(struct ipv4_subnet))
+ goto out;
+
+ len = sizeof(struct ipv4_subnet);
+
+ ret = -EFAULT;
+ if (copy_to_user(optval, &sk->sk_bind_subnet4, len))
+ goto out;
+
+ } else if (sk->sk_family == AF_INET6) {
+ ret = -EINVAL;
+ if (len < sizeof(struct ipv6_subnet))
+ goto out;
+
+ len = sizeof(struct ipv6_subnet);
+
+ ret = -EFAULT;
+ if (copy_to_user(optval, &sk->sk_bind_subnet6, len))
+ goto out;
+ }
+
+zero:
+ ret = -EFAULT;
+ if (put_user(len, optlen))
+ goto out;
+
+ ret = 0;
+out:
+ return ret;
+}
+
static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
{
if (valbool)
@@ -659,6 +764,9 @@ int sock_setsockopt(struct socket *sock, int level, int
optname,
if (optname == SO_BINDTODEVICE)
return sock_setbindtodevice(sk, optval, optlen);
+ else if (optname == SO_BINDTOSUBNET)
+ return sock_setbindtosubnet(sk, optval, optlen);
+
if (optlen < sizeof(int))
return -EINVAL;
@@ -1214,6 +1322,9 @@ int sock_getsockopt(struct socket *sock, int level, int
optname,
case SO_BINDTODEVICE:
return sock_getbindtodevice(sk, optval, optlen, len);
+ case SO_BINDTOSUBNET:
+ return sock_getbindtosubnet(sk, optval, optlen, len);
+
case SO_GET_FILTER:
len = sk_get_filter(sk, (struct sock_filter __user *)optval,
len);
if (len < 0)
--
2.7.2
