netpoll: prepare for ipv6

This patch adjusts some struct and functions, to prepare
for supporting IPv6.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netconsole.c

@@ -269,11 +269,13 @@ static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
 
 static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
 {
+	if (!nt->np.ipv6)
 		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
 }
 
 static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
 {
+	if (!nt->np.ipv6)
 		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
 }
 
@@ -410,7 +412,8 @@ static ssize_t store_local_ip(struct netconsole_target *nt,
 		return -EINVAL;
 	}
 
-	nt->np.local_ip = in_aton(buf);
+	if (!strnchr(buf, count, ':'))
+		nt->np.local_ip.ip = in_aton(buf);
 
 	return strnlen(buf, count);
 }
@@ -426,7 +429,8 @@ static ssize_t store_remote_ip(struct netconsole_target *nt,
 		return -EINVAL;
 	}
 
-	nt->np.remote_ip = in_aton(buf);
+	if (!strnchr(buf, count, ':'))
+		nt->np.remote_ip.ip = in_aton(buf);
 
 	return strnlen(buf, count);
 }

include/linux/netpoll.h

@@ -12,13 +12,22 @@
 #include <linux/rcupdate.h>
 #include <linux/list.h>
 
+union inet_addr {
+	__u32		all[4];
+	__be32		ip;
+	__be32		ip6[4];
+	struct in_addr	in;
+	struct in6_addr	in6;
+};
+
 struct netpoll {
 	struct net_device *dev;
 	char dev_name[IFNAMSIZ];
 	const char *name;
 	void (*rx_hook)(struct netpoll *, int, char *, int);
 
-	__be32 local_ip, remote_ip;
+	union inet_addr local_ip, remote_ip;
+	bool ipv6;
 	u16 local_port, remote_port;
 	u8 remote_mac[ETH_ALEN];
 
@@ -33,7 +42,7 @@ struct netpoll_info {
 	spinlock_t rx_lock;
 	struct list_head rx_np; /* netpolls that registered an rx_hook */
 
-	struct sk_buff_head arp_tx; /* list of arp requests to reply to */
+	struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
 	struct sk_buff_head txq;
 
 	struct delayed_work tx_work;

net/core/netpoll.c

@@ -55,7 +55,7 @@ static atomic_t trapped;
 	 MAX_UDP_CHUNK)
 
 static void zap_completion_queue(void);
-static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
+static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
 
 static unsigned int carrier_timeout = 4;
 module_param(carrier_timeout, uint, 0644);
@@ -181,13 +181,13 @@ static void poll_napi(struct net_device *dev)
 	}
 }
 
-static void service_arp_queue(struct netpoll_info *npi)
+static void service_neigh_queue(struct netpoll_info *npi)
 {
 	if (npi) {
 		struct sk_buff *skb;
 
-		while ((skb = skb_dequeue(&npi->arp_tx)))
-			netpoll_arp_reply(skb, npi);
+		while ((skb = skb_dequeue(&npi->neigh_tx)))
+			netpoll_neigh_reply(skb, npi);
 	}
 }
 
@@ -216,14 +216,14 @@ static void netpoll_poll_dev(struct net_device *dev)
 
 			bond_dev = netdev_master_upper_dev_get_rcu(dev);
 			bond_ni = rcu_dereference_bh(bond_dev->npinfo);
-			while ((skb = skb_dequeue(&ni->arp_tx))) {
+			while ((skb = skb_dequeue(&ni->neigh_tx))) {
 				skb->dev = bond_dev;
-				skb_queue_tail(&bond_ni->arp_tx, skb);
+				skb_queue_tail(&bond_ni->neigh_tx, skb);
 			}
 		}
 	}
 
-	service_arp_queue(ni);
+	service_neigh_queue(ni);
 
 	zap_completion_queue();
 }
@@ -386,7 +386,9 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 	static atomic_t ip_ident;
 
 	udp_len = len + sizeof(*udph);
+	if (!np->ipv6)
 		ip_len = udp_len + sizeof(*iph);
+
 	total_len = ip_len + LL_RESERVED_SPACE(np->dev);
 
 	skb = find_skb(np, total_len + np->dev->needed_tailroom,
@@ -403,9 +405,11 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 	udph->source = htons(np->local_port);
 	udph->dest = htons(np->remote_port);
 	udph->len = htons(udp_len);
+
+	if (!np->ipv6) {
 		udph->check = 0;
-	udph->check = csum_tcpudp_magic(np->local_ip,
-					np->remote_ip,
+		udph->check = csum_tcpudp_magic(np->local_ip.ip,
+						np->remote_ip.ip,
 						udp_len, IPPROTO_UDP,
 						csum_partial(udph, udp_len, 0));
 		if (udph->check == 0)
@@ -424,13 +428,15 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 		iph->ttl      = 64;
 		iph->protocol = IPPROTO_UDP;
 		iph->check    = 0;
-	put_unaligned(np->local_ip, &(iph->saddr));
-	put_unaligned(np->remote_ip, &(iph->daddr));
+		put_unaligned(np->local_ip.ip, &(iph->saddr));
+		put_unaligned(np->remote_ip.ip, &(iph->daddr));
 		iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
 
 		eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
 		skb_reset_mac_header(skb);
 		skb->protocol = eth->h_proto = htons(ETH_P_IP);
+	}
+
 	memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
 	memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
 
@@ -440,7 +446,7 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 }
 EXPORT_SYMBOL(netpoll_send_udp);
 
-static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
+static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 {
 	struct arphdr *arp;
 	unsigned char *arp_ptr;
@@ -451,7 +457,7 @@ static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 	struct netpoll *np, *tmp;
 	unsigned long flags;
 	int hlen, tlen;
-	int hits = 0;
+	int hits = 0, proto;
 
 	if (list_empty(&npinfo->rx_np))
 		return;
@@ -469,6 +475,8 @@ static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 	if (!hits)
 		return;
 
+	proto = ntohs(eth_hdr(skb)->h_proto);
+	if (proto == ETH_P_IP) {
 		/* No arp on this interface */
 		if (skb->dev->flags & IFF_NOARP)
 			return;
@@ -505,7 +513,7 @@ static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 
 		spin_lock_irqsave(&npinfo->rx_lock, flags);
 		list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
-		if (tip != np->local_ip)
+			if (tip != np->local_ip.ip)
 				continue;
 
 			hlen = LL_RESERVED_SPACE(np->dev);
@@ -557,6 +565,7 @@ static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 			break;
 		}
 		spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+	}
 }
 
 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
@@ -576,7 +585,7 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 	/* check if netpoll clients need ARP */
 	if (skb->protocol == htons(ETH_P_ARP) &&
 	    atomic_read(&trapped)) {
-		skb_queue_tail(&npinfo->arp_tx, skb);
+		skb_queue_tail(&npinfo->neigh_tx, skb);
 		return 1;
 	}
 
@@ -587,13 +596,14 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 	}
 
 	proto = ntohs(eth_hdr(skb)->h_proto);
-	if (proto != ETH_P_IP)
+	if (proto != ETH_P_IP && proto != ETH_P_IPV6)
 		goto out;
 	if (skb->pkt_type == PACKET_OTHERHOST)
 		goto out;
 	if (skb_shared(skb))
 		goto out;
 
+	if (proto == ETH_P_IP) {
 		if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 			goto out;
 		iph = (struct iphdr *)skb->data;
@@ -628,11 +638,10 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 			goto out;
 		if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
 			goto out;
-
 		list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
-		if (np->local_ip && np->local_ip != iph->daddr)
+			if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
 				continue;
-		if (np->remote_ip && np->remote_ip != iph->saddr)
+			if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
 				continue;
 			if (np->local_port && np->local_port != ntohs(uh->dest))
 				continue;
@@ -642,6 +651,7 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 				       ulen - sizeof(struct udphdr));
 			hits++;
 		}
+	}
 
 	if (!hits)
 		goto out;
@@ -661,17 +671,40 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 void netpoll_print_options(struct netpoll *np)
 {
 	np_info(np, "local port %d\n", np->local_port);
-	np_info(np, "local IP %pI4\n", &np->local_ip);
+	if (!np->ipv6)
+		np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
 	np_info(np, "interface '%s'\n", np->dev_name);
 	np_info(np, "remote port %d\n", np->remote_port);
-	np_info(np, "remote IP %pI4\n", &np->remote_ip);
+	if (!np->ipv6)
+		np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
 	np_info(np, "remote ethernet address %pM\n", np->remote_mac);
 }
 EXPORT_SYMBOL(netpoll_print_options);
 
+static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
+{
+	const char *end;
+
+	if (!strchr(str, ':') &&
+	    in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
+		if (!*end)
+			return 0;
+	}
+	if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
+#if IS_ENABLED(CONFIG_IPV6)
+		if (!*end)
+			return 1;
+#else
+		return -1;
+#endif
+	}
+	return -1;
+}
+
 int netpoll_parse_options(struct netpoll *np, char *opt)
 {
 	char *cur=opt, *delim;
+	int ipv6;
 
 	if (*cur != '@') {
 		if ((delim = strchr(cur, '@')) == NULL)
@@ -687,7 +720,11 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 		if ((delim = strchr(cur, '/')) == NULL)
 			goto parse_failed;
 		*delim = 0;
-		np->local_ip = in_aton(cur);
+		ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
+		if (ipv6 < 0)
+			goto parse_failed;
+		else
+			np->ipv6 = (bool)ipv6;
 		cur = delim;
 	}
 	cur++;
@@ -719,7 +756,13 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 	if ((delim = strchr(cur, '/')) == NULL)
 		goto parse_failed;
 	*delim = 0;
-	np->remote_ip = in_aton(cur);
+	ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
+	if (ipv6 < 0)
+		goto parse_failed;
+	else if (np->ipv6 != (bool)ipv6)
+		goto parse_failed;
+	else
+		np->ipv6 = (bool)ipv6;
 	cur = delim + 1;
 
 	if (*cur != 0) {
@@ -767,7 +810,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
 		INIT_LIST_HEAD(&npinfo->rx_np);
 
 		spin_lock_init(&npinfo->rx_lock);
-		skb_queue_head_init(&npinfo->arp_tx);
+		skb_queue_head_init(&npinfo->neigh_tx);
 		skb_queue_head_init(&npinfo->txq);
 		INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
 
@@ -859,10 +902,12 @@ int netpoll_setup(struct netpoll *np)
 		}
 	}
 
-	if (!np->local_ip) {
+	if (!np->local_ip.ip) {
+		if (!np->ipv6) {
 			rcu_read_lock();
 			in_dev = __in_dev_get_rcu(ndev);
 
+
 			if (!in_dev || !in_dev->ifa_list) {
 				rcu_read_unlock();
 				np_err(np, "no IP address for %s, aborting\n",
@@ -871,9 +916,10 @@ int netpoll_setup(struct netpoll *np)
 				goto put;
 			}
 
-		np->local_ip = in_dev->ifa_list->ifa_local;
+			np->local_ip.ip = in_dev->ifa_list->ifa_local;
 			rcu_read_unlock();
-		np_info(np, "local IP %pI4\n", &np->local_ip);
+			np_info(np, "local IP %pI4\n", &np->local_ip.ip);
+		}
 	}
 
 	/* fill up the skb queue */
@@ -906,7 +952,7 @@ static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
 	struct netpoll_info *npinfo =
 			container_of(rcu_head, struct netpoll_info, rcu);
 
-	skb_queue_purge(&npinfo->arp_tx);
+	skb_queue_purge(&npinfo->neigh_tx);
 	skb_queue_purge(&npinfo->txq);
 
 	/* we can't call cancel_delayed_work_sync here, as we are in softirq */