inet: move inet->hdrincl to inet->inet_flags

IP_HDRINCL socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: edumazet

include/net/inet_sock.h

@@ -231,7 +231,6 @@ struct inet_sock {
 	__u8			mc_ttl;
 	__u8			pmtudisc;
 	__u8			is_icsk:1,
-				hdrincl:1,
 				mc_loop:1,
 				transparent:1,
 				mc_all:1,
@@ -271,6 +270,7 @@ enum {
 	INET_FLAGS_RECVERR	= 9,
 	INET_FLAGS_RECVERR_RFC4884 = 10,
 	INET_FLAGS_FREEBIND	= 11,
+	INET_FLAGS_HDRINCL	= 12,
 };
 
 /* cmsg flags for inet */
@@ -397,7 +397,7 @@ static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 {
 	__u8 flags = 0;
 
-	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
+	if (inet_sk(sk)->transparent || inet_test_bit(HDRINCL, sk))
 		flags |= FLOWI_FLAG_ANYSRC;
 	return flags;
 }

net/ipv4/af_inet.c

@@ -338,7 +338,7 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 	if (SOCK_RAW == sock->type) {
 		inet->inet_num = protocol;
 		if (IPPROTO_RAW == protocol)
-			inet->hdrincl = 1;
+			inet_set_bit(HDRINCL, sk);
 	}
 
 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))

net/ipv4/inet_diag.c

@@ -185,7 +185,7 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
 	inet_sockopt.recverr	= inet_test_bit(RECVERR, sk);
 	inet_sockopt.is_icsk	= inet->is_icsk;
 	inet_sockopt.freebind	= inet_test_bit(FREEBIND, sk);
-	inet_sockopt.hdrincl	= inet->hdrincl;
+	inet_sockopt.hdrincl	= inet_test_bit(HDRINCL, sk);
 	inet_sockopt.mc_loop	= inet->mc_loop;
 	inet_sockopt.transparent = inet->transparent;
 	inet_sockopt.mc_all	= inet->mc_all;

net/ipv4/ip_output.c

@@ -1039,7 +1039,7 @@ static int __ip_append_data(struct sock *sk,
 			}
 		}
 	} else if ((flags & MSG_SPLICE_PAGES) && length) {
-		if (inet->hdrincl)
+		if (inet_test_bit(HDRINCL, sk))
 			return -EPERM;
 		if (rt->dst.dev->features & NETIF_F_SG &&
 		    getfrag == ip_generic_getfrag)
@@ -1467,7 +1467,8 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 		 * so icmphdr does not in skb linear region and can not get icmp_type
 		 * by icmp_hdr(skb)->type.
 		 */
-		if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
+		if (sk->sk_type == SOCK_RAW &&
+		    !inet_test_bit(HDRINCL, sk))
 			icmp_type = fl4->fl4_icmp_type;
 		else
 			icmp_type = icmp_hdr(skb)->type;

net/ipv4/ip_sockglue.c

@@ -988,6 +988,11 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 			return -EINVAL;
 		inet_assign_bit(FREEBIND, sk, val);
 		return 0;
+	case IP_HDRINCL:
+		if (sk->sk_type != SOCK_RAW)
+			return -ENOPROTOOPT;
+		inet_assign_bit(HDRINCL, sk, val);
+		return 0;
 	}
 
 	err = 0;
@@ -1052,13 +1057,6 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 			goto e_inval;
 		inet->uc_ttl = val;
 		break;
-	case IP_HDRINCL:
-		if (sk->sk_type != SOCK_RAW) {
-			err = -ENOPROTOOPT;
-			break;
-		}
-		inet->hdrincl = val ? 1 : 0;
-		break;
 	case IP_NODEFRAG:
 		if (sk->sk_type != SOCK_RAW) {
 			err = -ENOPROTOOPT;
@@ -1578,6 +1576,9 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 	case IP_FREEBIND:
 		val = inet_test_bit(FREEBIND, sk);
 		goto copyval;
+	case IP_HDRINCL:
+		val = inet_test_bit(HDRINCL, sk);
+		goto copyval;
 	}
 
 	if (needs_rtnl)
@@ -1625,9 +1626,6 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 		       inet->uc_ttl);
 		break;
 	}
-	case IP_HDRINCL:
-		val = inet->hdrincl;
-		break;
 	case IP_NODEFRAG:
 		val = inet->nodefrag;
 		break;

net/ipv4/raw.c

@@ -251,7 +251,7 @@ static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
 		const struct iphdr *iph = (const struct iphdr *)skb->data;
 		u8 *payload = skb->data + (iph->ihl << 2);
 
-		if (inet->hdrincl)
+		if (inet_test_bit(HDRINCL, sk))
 			payload = skb->data;
 		ip_icmp_error(sk, skb, err, 0, info, payload);
 	}
@@ -491,12 +491,8 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	if (len > 0xFFFF)
 		goto out;
 
-	/* hdrincl should be READ_ONCE(inet->hdrincl)
-	 * but READ_ONCE() doesn't work with bit fields.
-	 * Doing this indirectly yields the same result.
-	 */
-	hdrincl = inet->hdrincl;
-	hdrincl = READ_ONCE(hdrincl);
+	hdrincl = inet_test_bit(HDRINCL, sk);
+
 	/*
 	 *	Check the flags.
 	 */

net/ipv4/route.c

@@ -515,13 +515,12 @@ static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
 	__u8 scope = RT_SCOPE_UNIVERSE;
 
 	if (sk) {
-		const struct inet_sock *inet = inet_sk(sk);
-
 		oif = sk->sk_bound_dev_if;
 		mark = READ_ONCE(sk->sk_mark);
 		tos = ip_sock_rt_tos(sk);
 		scope = ip_sock_rt_scope(sk);
-		prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
+		prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW :
+						    sk->sk_protocol;
 	}
 
 	flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope,
@@ -555,7 +554,8 @@ static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
 	flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark),
 			   ip_sock_rt_tos(sk) & IPTOS_RT_MASK,
 			   ip_sock_rt_scope(sk),
-			   inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
+			   inet_test_bit(HDRINCL, sk) ?
+				IPPROTO_RAW : sk->sk_protocol,
 			   inet_sk_flowi_flags(sk),
 			   daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
 	rcu_read_unlock();

net/ipv6/af_inet6.c

@@ -205,7 +205,7 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
 	if (SOCK_RAW == sock->type) {
 		inet->inet_num = protocol;
 		if (IPPROTO_RAW == protocol)
-			inet->hdrincl = 1;
+			inet_set_bit(HDRINCL, sk);
 	}
 
 	sk->sk_destruct		= inet6_sock_destruct;

net/ipv6/ip6_output.c

@@ -1591,7 +1591,7 @@ static int __ip6_append_data(struct sock *sk,
 			}
 		}
 	} else if ((flags & MSG_SPLICE_PAGES) && length) {
-		if (inet_sk(sk)->hdrincl)
+		if (inet_test_bit(HDRINCL, sk))
 			return -EPERM;
 		if (rt->dst.dev->features & NETIF_F_SG &&
 		    getfrag == ip_generic_getfrag)
@@ -1995,7 +1995,8 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 		u8 icmp6_type;
 
-		if (sk->sk_socket->type == SOCK_RAW && !inet_sk(sk)->hdrincl)
+		if (sk->sk_socket->type == SOCK_RAW &&
+		   !inet_test_bit(HDRINCL, sk))
 			icmp6_type = fl6->fl6_icmp_type;
 		else
 			icmp6_type = icmp6_hdr(skb)->icmp6_type;

net/ipv6/raw.c

@@ -291,7 +291,6 @@ static void rawv6_err(struct sock *sk, struct sk_buff *skb,
 	       struct inet6_skb_parm *opt,
 	       u8 type, u8 code, int offset, __be32 info)
 {
-	struct inet_sock *inet = inet_sk(sk);
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	int err;
 	int harderr;
@@ -315,7 +314,7 @@ static void rawv6_err(struct sock *sk, struct sk_buff *skb,
 	}
 	if (np->recverr) {
 		u8 *payload = skb->data;
-		if (!inet->hdrincl)
+		if (!inet_test_bit(HDRINCL, sk))
 			payload += offset;
 		ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
 	}
@@ -406,7 +405,7 @@ int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
 							 skb->len,
 							 inet->inet_num, 0));
 
-	if (inet->hdrincl) {
+	if (inet_test_bit(HDRINCL, sk)) {
 		if (skb_checksum_complete(skb)) {
 			atomic_inc(&sk->sk_drops);
 			kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
@@ -762,12 +761,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	if (msg->msg_flags & MSG_OOB)
 		return -EOPNOTSUPP;
 
-	/* hdrincl should be READ_ONCE(inet->hdrincl)
-	 * but READ_ONCE() doesn't work with bit fields.
-	 * Doing this indirectly yields the same result.
-	 */
-	hdrincl = inet->hdrincl;
-	hdrincl = READ_ONCE(hdrincl);
+	hdrincl = inet_test_bit(HDRINCL, sk);
 
 	/*
 	 *	Get and verify the address.
@@ -1000,7 +994,7 @@ static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,
 	case IPV6_HDRINCL:
 		if (sk->sk_type != SOCK_RAW)
 			return -EINVAL;
-		inet_sk(sk)->hdrincl = !!val;
+		inet_assign_bit(HDRINCL, sk, val);
 		return 0;
 	case IPV6_CHECKSUM:
 		if (inet_sk(sk)->inet_num == IPPROTO_ICMPV6 &&
@@ -1068,7 +1062,7 @@ static int do_rawv6_getsockopt(struct sock *sk, int level, int optname,
 
 	switch (optname) {
 	case IPV6_HDRINCL:
-		val = inet_sk(sk)->hdrincl;
+		val = inet_test_bit(HDRINCL, sk);
 		break;
 	case IPV6_CHECKSUM:
 		/*