ipv4: ipcm_cookie initializers

Initialize the cookie in one location to reduce code duplication and
avoid bugs from inconsistent initialization, such as that fixed in
commit 9887cba19978 ("ip: limit use of gso_size to udp").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -79,6 +79,21 @@ struct ipcm_cookie {
 	__u16			gso_size;
 };
 
+static inline void ipcm_init(struct ipcm_cookie *ipcm)
+{
+	*ipcm = (struct ipcm_cookie) { .tos = -1 };
+}
+
+static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
+				const struct inet_sock *inet)
+{
+	ipcm_init(ipcm);
+
+	ipcm->sockc.tsflags = inet->sk.sk_tsflags;
+	ipcm->oif = inet->sk.sk_bound_dev_if;
+	ipcm->addr = inet->inet_saddr;
+}
+
 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
 

net/ipv4/icmp.c

@@ -429,15 +429,11 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 
 	icmp_param->data.icmph.checksum = 0;
 
+	ipcm_init(&ipc);
 	inet->tos = ip_hdr(skb)->tos;
 	sk->sk_mark = mark;
 	daddr = ipc.addr = ip_hdr(skb)->saddr;
 	saddr = fib_compute_spec_dst(skb);
-	ipc.opt = NULL;
-	ipc.tx_flags = 0;
-	ipc.ttl = 0;
-	ipc.tos = -1;
-	ipc.sockc.transmit_time = 0;
 
 	if (icmp_param->replyopts.opt.opt.optlen) {
 		ipc.opt = &icmp_param->replyopts.opt;
@@ -711,12 +707,9 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	icmp_param.offset = skb_network_offset(skb_in);
 	inet_sk(sk)->tos = tos;
 	sk->sk_mark = mark;
+	ipcm_init(&ipc);
 	ipc.addr = iph->saddr;
 	ipc.opt = &icmp_param.replyopts.opt;
-	ipc.tx_flags = 0;
-	ipc.ttl = 0;
-	ipc.tos = -1;
-	ipc.sockc.transmit_time = 0;
 
 	rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark,
 			       type, code, &icmp_param);

net/ipv4/ip_output.c

@@ -1548,12 +1548,8 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 	if (__ip_options_echo(net, &replyopts.opt.opt, skb, sopt))
 		return;
 
+	ipcm_init(&ipc);
 	ipc.addr = daddr;
-	ipc.opt = NULL;
-	ipc.tx_flags = 0;
-	ipc.ttl = 0;
-	ipc.tos = -1;
-	ipc.sockc.transmit_time = 0;
 
 	if (replyopts.opt.opt.optlen) {
 		ipc.opt = &replyopts.opt;

net/ipv4/ping.c

@@ -739,14 +739,7 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		/* no remote port */
 	}
 
-	ipc.sockc.tsflags = sk->sk_tsflags;
-	ipc.addr = inet->inet_saddr;
-	ipc.opt = NULL;
-	ipc.oif = sk->sk_bound_dev_if;
-	ipc.tx_flags = 0;
-	ipc.ttl = 0;
-	ipc.tos = -1;
-	ipc.sockc.transmit_time = 0;
+	ipcm_init_sk(&ipc, inet);
 
 	if (msg->msg_controllen) {
 		err = ip_cmsg_send(sk, msg, &ipc, false);

net/ipv4/raw.c

@@ -562,14 +562,7 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		daddr = inet->inet_daddr;
 	}
 
-	ipc.sockc.tsflags = sk->sk_tsflags;
-	ipc.sockc.transmit_time = 0;
-	ipc.addr = inet->inet_saddr;
-	ipc.opt = NULL;
-	ipc.tx_flags = 0;
-	ipc.ttl = 0;
-	ipc.tos = -1;
-	ipc.oif = sk->sk_bound_dev_if;
+	ipcm_init_sk(&ipc, inet);
 
 	if (msg->msg_controllen) {
 		err = ip_cmsg_send(sk, msg, &ipc, false);

net/ipv4/udp.c

@@ -926,12 +926,6 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
 		return -EOPNOTSUPP;
 
-	ipc.opt = NULL;
-	ipc.tx_flags = 0;
-	ipc.ttl = 0;
-	ipc.tos = -1;
-	ipc.sockc.transmit_time = 0;
-
 	getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
 
 	fl4 = &inet->cork.fl.u.ip4;
@@ -978,9 +972,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		connected = 1;
 	}
 
-	ipc.sockc.tsflags = sk->sk_tsflags;
-	ipc.addr = inet->inet_saddr;
-	ipc.oif = sk->sk_bound_dev_if;
+	ipcm_init_sk(&ipc, inet);
 	ipc.gso_size = up->gso_size;
 
 	if (msg->msg_controllen) {