1 files changed, 158 insertions, 113 deletions

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 501e451be91..ba2f5e710af 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -34,11 +34,15 @@
  *
  ****************************************************************/
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/mm.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/console.h>
 #include <linux/moduleparam.h>
+#include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/netpoll.h>
 #include <linux/inet.h>
@@ -53,7 +57,11 @@ MODULE_LICENSE("GPL");
 
 static char config[MAX_PARAM_LENGTH];
 module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
-MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
+MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]");
+
+static bool oops_only = false;
+module_param(oops_only, bool, 0600);
+MODULE_PARM_DESC(oops_only, "Only log oops messages");
 
 #ifndef	MODULE
 static int __init option_setup(char *opt)
@@ -96,6 +104,7 @@ struct netconsole_target {
 	struct config_item	item;
 #endif
 	int			enabled;
+	struct mutex		mutex;
 	struct netpoll		np;
 };
 
@@ -168,15 +177,14 @@ static struct netconsole_target *alloc_param_target(char *target_config)
 	 * Note that these targets get their config_item fields zeroed-out.
 	 */
 	nt = kzalloc(sizeof(*nt), GFP_KERNEL);
-	if (!nt) {
-		printk(KERN_ERR "netconsole: failed to allocate memory\n");
+	if (!nt)
 		goto fail;
-	}
 
 	nt->np.name = "netconsole";
 	strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
 	nt->np.local_port = 6665;
 	nt->np.remote_port = 6666;
+	mutex_init(&nt->mutex);
 	memset(nt->np.remote_mac, 0xff, ETH_ALEN);
 
 	/* Parse parameters and setup netpoll */
@@ -241,34 +249,6 @@ static struct netconsole_target *to_target(struct config_item *item)
 }
 
 /*
- * Wrapper over simple_strtol (base 10) with sanity and range checking.
- * We return (signed) long only because we may want to return errors.
- * Do not use this to convert numbers that are allowed to be negative.
- */
-static long strtol10_check_range(const char *cp, long min, long max)
-{
-	long ret;
-	char *p = (char *) cp;
-
-	WARN_ON(min < 0);
-	WARN_ON(max < min);
-
-	ret = simple_strtol(p, &p, 10);
-
-	if (*p && (*p != '\n')) {
-		printk(KERN_ERR "netconsole: invalid input\n");
-		return -EINVAL;
-	}
-	if ((ret < min) || (ret > max)) {
-		printk(KERN_ERR "netconsole: input %ld must be between "
-				"%ld and %ld\n", ret, min, max);
-		return -EINVAL;
-	}
-
-	return ret;
-}
-
-/*
  * Attribute operations for netconsole_target.
  */
 
@@ -294,30 +274,31 @@ static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
 
 static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
-			HIPQUAD(nt->np.local_ip));
+	if (nt->np.ipv6)
+		return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.local_ip.in6);
+	else
+		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
 }
 
 static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
-			HIPQUAD(nt->np.remote_ip));
+	if (nt->np.ipv6)
+		return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.remote_ip.in6);
+	else
+		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
 }
 
 static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
 {
 	struct net_device *dev = nt->np.dev;
+	static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
-	DECLARE_MAC_BUF(mac);
-	return snprintf(buf, PAGE_SIZE, "%s\n", dev ?
-			print_mac(mac, dev->dev_addr) : "ff:ff:ff:ff:ff:ff");
+	return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
 }
 
 static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
 {
-	DECLARE_MAC_BUF(mac);
-	return snprintf(buf, PAGE_SIZE, "%s\n",
-			print_mac(mac, nt->np.remote_mac));
+	return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
 }
 
 /*
@@ -331,15 +312,22 @@ static ssize_t store_enabled(struct netconsole_target *nt,
 			     const char *buf,
 			     size_t count)
 {
+	unsigned long flags;
+	int enabled;
 	int err;
-	long enabled;
 
-	enabled = strtol10_check_range(buf, 0, 1);
-	if (enabled < 0)
-		return enabled;
+	err = kstrtoint(buf, 10, &enabled);
+	if (err < 0)
+		return err;
+	if (enabled < 0 || enabled > 1)
+		return -EINVAL;
+	if (enabled == nt->enabled) {
+		pr_info("network logging has already %s\n",
+			nt->enabled ? "started" : "stopped");
+		return -EINVAL;
+	}
 
 	if (enabled) {	/* 1 */
-
 		/*
 		 * Skip netpoll_parse_options() -- all the attributes are
 		 * already configured via configfs. Just print them out.
@@ -350,9 +338,15 @@ static ssize_t store_enabled(struct netconsole_target *nt,
 		if (err)
 			return err;
 
-		printk(KERN_INFO "netconsole: network logging started\n");
-
+		pr_info("netconsole: network logging started\n");
 	} else {	/* 0 */
+		/* We need to disable the netconsole before cleaning it up
+		 * otherwise we might end up in write_msg() with
+		 * nt->np.dev == NULL and nt->enabled == 1
+		 */
+		spin_lock_irqsave(&target_list_lock, flags);
+		nt->enabled = 0;
+		spin_unlock_irqrestore(&target_list_lock, flags);
 		netpoll_cleanup(&nt->np);
 	}
 
@@ -368,9 +362,8 @@ static ssize_t store_dev_name(struct netconsole_target *nt,
 	size_t len;
 
 	if (nt->enabled) {
-		printk(KERN_ERR "netconsole: target (%s) is enabled, "
-				"disable to update parameters\n",
-				config_item_name(&nt->item));
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		return -EINVAL;
 	}
 
@@ -388,22 +381,17 @@ static ssize_t store_local_port(struct netconsole_target *nt,
 				const char *buf,
 				size_t count)
 {
-	long local_port;
-#define __U16_MAX	((__u16) ~0U)
+	int rv;
 
 	if (nt->enabled) {
-		printk(KERN_ERR "netconsole: target (%s) is enabled, "
-				"disable to update parameters\n",
-				config_item_name(&nt->item));
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		return -EINVAL;
 	}
 
-	local_port = strtol10_check_range(buf, 0, __U16_MAX);
-	if (local_port < 0)
-		return local_port;
-
-	nt->np.local_port = local_port;
-
+	rv = kstrtou16(buf, 10, &nt->np.local_port);
+	if (rv < 0)
+		return rv;
 	return strnlen(buf, count);
 }
 
@@ -411,22 +399,17 @@ static ssize_t store_remote_port(struct netconsole_target *nt,
 				 const char *buf,
 				 size_t count)
 {
-	long remote_port;
-#define __U16_MAX	((__u16) ~0U)
+	int rv;
 
 	if (nt->enabled) {
-		printk(KERN_ERR "netconsole: target (%s) is enabled, "
-				"disable to update parameters\n",
-				config_item_name(&nt->item));
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		return -EINVAL;
 	}
 
-	remote_port = strtol10_check_range(buf, 0, __U16_MAX);
-	if (remote_port < 0)
-		return remote_port;
-
-	nt->np.remote_port = remote_port;
-
+	rv = kstrtou16(buf, 10, &nt->np.remote_port);
+	if (rv < 0)
+		return rv;
 	return strnlen(buf, count);
 }
 
@@ -435,13 +418,27 @@ static ssize_t store_local_ip(struct netconsole_target *nt,
 			      size_t count)
 {
 	if (nt->enabled) {
-		printk(KERN_ERR "netconsole: target (%s) is enabled, "
-				"disable to update parameters\n",
-				config_item_name(&nt->item));
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		return -EINVAL;
 	}
 
-	nt->np.local_ip = ntohl(in_aton(buf));
+	if (strnchr(buf, count, ':')) {
+		const char *end;
+		if (in6_pton(buf, count, nt->np.local_ip.in6.s6_addr, -1, &end) > 0) {
+			if (*end && *end != '\n') {
+				pr_err("invalid IPv6 address at: <%c>\n", *end);
+				return -EINVAL;
+			}
+			nt->np.ipv6 = true;
+		} else
+			return -EINVAL;
+	} else {
+		if (!nt->np.ipv6) {
+			nt->np.local_ip.ip = in_aton(buf);
+		} else
+			return -EINVAL;
+	}
 
 	return strnlen(buf, count);
 }
@@ -451,13 +448,27 @@ static ssize_t store_remote_ip(struct netconsole_target *nt,
 			       size_t count)
 {
 	if (nt->enabled) {
-		printk(KERN_ERR "netconsole: target (%s) is enabled, "
-				"disable to update parameters\n",
-				config_item_name(&nt->item));
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		return -EINVAL;
 	}
 
-	nt->np.remote_ip = ntohl(in_aton(buf));
+	if (strnchr(buf, count, ':')) {
+		const char *end;
+		if (in6_pton(buf, count, nt->np.remote_ip.in6.s6_addr, -1, &end) > 0) {
+			if (*end && *end != '\n') {
+				pr_err("invalid IPv6 address at: <%c>\n", *end);
+				return -EINVAL;
+			}
+			nt->np.ipv6 = true;
+		} else
+			return -EINVAL;
+	} else {
+		if (!nt->np.ipv6) {
+			nt->np.remote_ip.ip = in_aton(buf);
+		} else
+			return -EINVAL;
+	}
 
 	return strnlen(buf, count);
 }
@@ -467,33 +478,20 @@ static ssize_t store_remote_mac(struct netconsole_target *nt,
 				size_t count)
 {
 	u8 remote_mac[ETH_ALEN];
-	char *p = (char *) buf;
-	int i;
 
 	if (nt->enabled) {
-		printk(KERN_ERR "netconsole: target (%s) is enabled, "
-				"disable to update parameters\n",
-				config_item_name(&nt->item));
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		return -EINVAL;
 	}
 
-	for (i = 0; i < ETH_ALEN - 1; i++) {
-		remote_mac[i] = simple_strtoul(p, &p, 16);
-		if (*p != ':')
-			goto invalid;
-		p++;
-	}
-	remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16);
-	if (*p && (*p != '\n'))
-		goto invalid;
-
+	if (!mac_pton(buf, remote_mac))
+		return -EINVAL;
+	if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
+		return -EINVAL;
 	memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
 
 	return strnlen(buf, count);
-
-invalid:
-	printk(KERN_ERR "netconsole: invalid input\n");
-	return -EINVAL;
 }
 
 /*
@@ -563,8 +561,10 @@ static ssize_t netconsole_target_attr_store(struct config_item *item,
 	struct netconsole_target_attr *na =
 		container_of(attr, struct netconsole_target_attr, attr);
 
+	mutex_lock(&nt->mutex);
 	if (na->store)
 		ret = na->store(nt, buf, count);
+	mutex_unlock(&nt->mutex);
 
 	return ret;
 }
@@ -596,15 +596,14 @@ static struct config_item *make_netconsole_target(struct config_group *group,
 	 * Target is disabled at creation (enabled == 0).
 	 */
 	nt = kzalloc(sizeof(*nt), GFP_KERNEL);
-	if (!nt) {
-		printk(KERN_ERR "netconsole: failed to allocate memory\n");
-		return NULL;
-	}
+	if (!nt)
+		return ERR_PTR(-ENOMEM);
 
 	nt->np.name = "netconsole";
 	strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
 	nt->np.local_port = 6665;
 	nt->np.remote_port = 6666;
+	mutex_init(&nt->mutex);
 	memset(nt->np.remote_mac, 0xff, ETH_ALEN);
 
 	/* Initialize the config_item member */
@@ -662,17 +661,19 @@ static struct configfs_subsystem netconsole_subsys = {
 
 /* Handle network interface device notifications */
 static int netconsole_netdev_event(struct notifier_block *this,
-				   unsigned long event,
-				   void *ptr)
+				   unsigned long event, void *ptr)
 {
 	unsigned long flags;
 	struct netconsole_target *nt;
-	struct net_device *dev = ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	bool stopped = false;
 
-	if (!(event == NETDEV_CHANGENAME))
+	if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
+	      event == NETDEV_RELEASE || event == NETDEV_JOIN))
 		goto done;
 
 	spin_lock_irqsave(&target_list_lock, flags);
+restart:
 	list_for_each_entry(nt, &target_list, list) {
 		netconsole_target_get(nt);
 		if (nt->np.dev == dev) {
@@ -680,11 +681,44 @@ static int netconsole_netdev_event(struct notifier_block *this,
 			case NETDEV_CHANGENAME:
 				strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
 				break;
+			case NETDEV_RELEASE:
+			case NETDEV_JOIN:
+			case NETDEV_UNREGISTER:
+				/* rtnl_lock already held
+				 * we might sleep in __netpoll_cleanup()
+				 */
+				spin_unlock_irqrestore(&target_list_lock, flags);
+
+				__netpoll_cleanup(&nt->np);
+
+				spin_lock_irqsave(&target_list_lock, flags);
+				dev_put(nt->np.dev);
+				nt->np.dev = NULL;
+				nt->enabled = 0;
+				stopped = true;
+				netconsole_target_put(nt);
+				goto restart;
 			}
 		}
 		netconsole_target_put(nt);
 	}
 	spin_unlock_irqrestore(&target_list_lock, flags);
+	if (stopped) {
+		const char *msg = "had an event";
+		switch (event) {
+		case NETDEV_UNREGISTER:
+			msg = "unregistered";
+			break;
+		case NETDEV_RELEASE:
+			msg = "released slaves";
+			break;
+		case NETDEV_JOIN:
+			msg = "is joining a master device";
+			break;
+		}
+		pr_info("network logging stopped on interface %s as it %s\n",
+			dev->name, msg);
+	}
 
 done:
 	return NOTIFY_DONE;
@@ -701,6 +735,8 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
 	struct netconsole_target *nt;
 	const char *tmp;
 
+	if (oops_only && !oops_in_progress)
+		return;
 	/* Avoid taking lock and disabling interrupts unnecessarily */
 	if (list_empty(&target_list))
 		return;
@@ -730,7 +766,7 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
 
 static struct console netconsole = {
 	.name	= "netcon",
-	.flags	= CON_ENABLED | CON_PRINTBUFFER,
+	.flags	= CON_ENABLED,
 	.write	= write_msg,
 };
 
@@ -749,6 +785,9 @@ static int __init init_netconsole(void)
 				err = PTR_ERR(nt);
 				goto fail;
 			}
+			/* Dump existing printks when we register */
+			netconsole.flags |= CON_PRINTBUFFER;
+
 			spin_lock_irqsave(&target_list_lock, flags);
 			list_add(&nt->list, &target_list);
 			spin_unlock_irqrestore(&target_list_lock, flags);
@@ -764,7 +803,7 @@ static int __init init_netconsole(void)
 		goto undonotifier;
 
 	register_console(&netconsole);
-	printk(KERN_INFO "netconsole: network logging started\n");
+	pr_info("network logging started\n");
 
 	return err;
 
@@ -772,7 +811,7 @@ undonotifier:
 	unregister_netdevice_notifier(&netconsole_netdev_notifier);
 
 fail:
-	printk(KERN_ERR "netconsole: cleaning up\n");
+	pr_err("cleaning up\n");
 
 	/*
 	 * Remove all targets and destroy them (only targets created
@@ -809,5 +848,11 @@ static void __exit cleanup_netconsole(void)
 	}
 }
 
-module_init(init_netconsole);
+/*
+ * Use late_initcall to ensure netconsole is
+ * initialized after network device driver if built-in.
+ *
+ * late_initcall() and module_init() are identical if built as module.
+ */
+late_initcall(init_netconsole);
 module_exit(cleanup_netconsole);