5 files changed, 76 insertions, 9 deletions

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index fabee6db0abb..421d41ef4e9c 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -370,6 +370,71 @@ out:
 	return NULL;
 }
 
+/* Shall not be called with lock_sock held */
+static inline struct sk_buff *bt_skb_sendmsg(struct sock *sk,
+					     struct msghdr *msg,
+					     size_t len, size_t mtu,
+					     size_t headroom, size_t tailroom)
+{
+	struct sk_buff *skb;
+	size_t size = min_t(size_t, len, mtu);
+	int err;
+
+	skb = bt_skb_send_alloc(sk, size + headroom + tailroom,
+				msg->msg_flags & MSG_DONTWAIT, &err);
+	if (!skb)
+		return ERR_PTR(err);
+
+	skb_reserve(skb, headroom);
+	skb_tailroom_reserve(skb, mtu, tailroom);
+
+	if (!copy_from_iter_full(skb_put(skb, size), size, &msg->msg_iter)) {
+		kfree_skb(skb);
+		return ERR_PTR(-EFAULT);
+	}
+
+	skb->priority = sk->sk_priority;
+
+	return skb;
+}
+
+/* Similar to bt_skb_sendmsg but can split the msg into multiple fragments
+ * accourding to the MTU.
+ */
+static inline struct sk_buff *bt_skb_sendmmsg(struct sock *sk,
+					      struct msghdr *msg,
+					      size_t len, size_t mtu,
+					      size_t headroom, size_t tailroom)
+{
+	struct sk_buff *skb, **frag;
+
+	skb = bt_skb_sendmsg(sk, msg, len, mtu, headroom, tailroom);
+	if (IS_ERR_OR_NULL(skb))
+		return skb;
+
+	len -= skb->len;
+	if (!len)
+		return skb;
+
+	/* Add remaining data over MTU as continuation fragments */
+	frag = &skb_shinfo(skb)->frag_list;
+	while (len) {
+		struct sk_buff *tmp;
+
+		tmp = bt_skb_sendmsg(sk, msg, len, mtu, headroom, tailroom);
+		if (IS_ERR(tmp)) {
+			return skb;
+		}
+
+		len -= tmp->len;
+
+		*frag = tmp;
+		frag = &(*frag)->next;
+	}
+
+	return skb;
+}
+
 int bt_to_errno(u16 code);
 
 void hci_sock_set_flag(struct sock *sk, int nr);
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 34c4436fd18f..58db7c69c146 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -107,7 +107,8 @@ static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
 
 static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
 {
-	if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
+	if (!sk->sk_mark &&
+	    READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
 		return skb->mark;
 
 	return sk->sk_mark;
@@ -375,7 +376,7 @@ static inline bool inet_get_convert_csum(struct sock *sk)
 static inline bool inet_can_nonlocal_bind(struct net *net,
 					  struct inet_sock *inet)
 {
-	return net->ipv4.sysctl_ip_nonlocal_bind ||
+	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
 		inet->freebind || inet->transparent;
 }
 
diff --git a/include/net/ip.h b/include/net/ip.h
index 3f3ea86b2173..db841ab388c0 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -381,7 +381,7 @@ void ipfrag_init(void);
 void ip_static_sysctl_init(void);
 
 #define IP4_REPLY_MARK(net, mark) \
-	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
+	(READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
 
 static inline bool ip_is_fragment(const struct iphdr *iph)
 {
@@ -442,7 +442,7 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 	struct net *net = dev_net(dst->dev);
 	unsigned int mtu;
 
-	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
+	if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
 	    ip_mtu_locked(dst) ||
 	    !forwarding)
 		return dst_mtu(dst);
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 65be8bd1f0f4..aaf1d5d5a13b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1373,8 +1373,8 @@ static inline void tcp_slow_start_after_idle_check(struct sock *sk)
 	struct tcp_sock *tp = tcp_sk(sk);
 	s32 delta;
 
-	if (!sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle || tp->packets_out ||
-	    ca_ops->cong_control)
+	if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) ||
+	    tp->packets_out || ca_ops->cong_control)
 		return;
 	delta = tcp_jiffies32 - tp->lsndtime;
 	if (delta > inet_csk(sk)->icsk_rto)
@@ -1465,7 +1465,8 @@ static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp)
 
 static inline int tcp_fin_time(const struct sock *sk)
 {
-	int fin_timeout = tcp_sk(sk)->linger2 ? : sock_net(sk)->ipv4.sysctl_tcp_fin_timeout;
+	int fin_timeout = tcp_sk(sk)->linger2 ? :
+		READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout);
 	const int rto = inet_csk(sk)->icsk_rto;
 
 	if (fin_timeout < (rto << 2) - (rto >> 1))
@@ -1946,7 +1947,7 @@ void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr);
 static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp)
 {
 	struct net *net = sock_net((struct sock *)tp);
-	return tp->notsent_lowat ?: net->ipv4.sysctl_tcp_notsent_lowat;
+	return tp->notsent_lowat ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat);
 }
 
 /* @wake is one when sk_stream_write_space() calls us.
diff --git a/include/net/udp.h b/include/net/udp.h
index 9787a42f7ed3..e66854e767dc 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -252,7 +252,7 @@ static inline bool udp_sk_bound_dev_eq(struct net *net, int bound_dev_if,
 				       int dif, int sdif)
 {
 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
-	return inet_bound_dev_eq(!!net->ipv4.sysctl_udp_l3mdev_accept,
+	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_udp_l3mdev_accept),
 				 bound_dev_if, dif, sdif);
 #else
 	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);