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proposal for dynamic configurable netconsole

RFC PATCH In review Keiichi KII 4 participants 13 messages Mar 20, 2007 – Mar 22, 2007

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Keiichi KII

author
#0 lore raw

cover proposal for dynamic configurable netconsole

From: Keiichi KII <[email protected]>

The netconsole is a very useful module for collecting kernel message under certain circumstances(e.g. disk logging fails, serial port is unavailable).

But current netconsole is not flexible. For example, if you want to change ip address for logging agent, in the case of built-in netconsole, you can't change config except for changing boot parameter and rebooting your system, or in the case of module netconsole, you need to remove it and reload with different parameters.

So, I propose the following extended features for netconsole.

1) support for multiple logging agents.
2) add interface to access each parameter of netconsole using sysfs.

[changes since take2]
-changing kernel base from 2.6.20-rc1-mm1 to 2.6.21-rc3.mm2. -using symbolic link for network device.
-changing in part interface from sysfs to ioctl,
because Stephen Hemminger advised us that it is a misuse that sysfs has the behavior with magic side effect such as adding/removing port.

This patch is for linux-2.6.21-rc3-mm2 and is divided to each function. Your comments are very welcome.

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---

author
#1 lore raw

RFC PATCH 1/6 marking __init

From: Keiichi KII <[email protected]>

This patch contains the following cleanups.
- add __init for initialization functions(option_setup() and init_netconsole()).

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---

drivers/net/netconsole.c +2 -2
Index: linux-mm/drivers/net/netconsole.c
===================================================================
@@ -91,7 +91,7 @@ static struct console netconsole = {
 	.write = write_msg
 };
 
-static int option_setup(char *opt)
+static int __init option_setup(char *opt)
 {
 	configured = !netpoll_parse_options(&np, opt);
 	return 1;

@@ -99,7 +99,7 @@ static int option_setup(char *opt)
 
 __setup("netconsole=", option_setup);
 
-static int init_netconsole(void)
+static int __init init_netconsole(void)
 {
 	int err;
Acked-by on v1 1/6
#2 lore raw

Re: [RFC][PATCH -mm take3 1/6][resend] marking __init

Quoted 23 lines · Keiichi KII

From: Keiichi KII <[email protected]>

This patch contains the following cleanups.
- add __init for initialization functions(option_setup() and init_netconsole()).

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---
Index: linux-mm/drivers/net/netconsole.c
===================================================================

drivers/net/netconsole.c +1 -1
@@ -91,7 +91,7 @@ static struct console netconsole = {
 	.write = write_msg
 };
 
-static int option_setup(char *opt)
+static int __init option_setup(char *opt)
 {
 	configured = !netpoll_parse_options(&np, opt);
 	return 1;

drivers/net/netconsole.c static int option_setup(char *opt) · line 104

Quoted 7 lines
drivers/net/netconsole.c +1 -1
@@ -99,7 +99,7 @@ static int option_setup(char *opt)
 
 __setup("netconsole=", option_setup);
 
-static int init_netconsole(void)
+static int __init init_netconsole(void)
 {
 	int err;

This is fine.

Acked-by Matt Mackall <[email protected]>
Signature · 1 line
Mathematics is the supreme nostalgia of our time.
author
#3 lore raw

RFC PATCH 2/6 support multiple logging

In reply to Keiichi KII

From: Keiichi KII <[email protected]>

This patch contains the following changes for supporting multiple logging
agents.

1. extend netconsole to multiple netpolls
To send kernel messages to multiple logging agents, extend netcosnole
to be able to use multiple netpolls. Each netpoll sends kernel messages to its own logging agent.

2. change config parameter format
We change config parameter format from single configuration to multiple configurations separated by ';'.

ex) sending kernel messages to destination1 and destination2 using eth0.

    modprobe netconsole \
            netconsole="@/eth0,@[destination1]/;@/eth0,@[destination2]/"
Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---

drivers/net/netconsole.c +96 -15
Index: linux-2.6.19.5/drivers/net/netconsole.c
===================================================================
@@ -54,6 +54,20 @@ static char config[256];
 module_param_string(netconsole, config, 256, 0);
 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
 
+struct netconsole_target {
+	struct list_head list;
+	int id;
+	struct netpoll np;
+};
+
+static int add_target(char* target_config);
+static void cleanup_netconsole(void);
+static void delete_target(struct netconsole_target *nt);
+
+static LIST_HEAD(target_list);
+
+static DEFINE_SPINLOCK(target_list_lock);
+
 static struct netpoll np = {
 	.name = "netconsole",
 	.dev_name = "eth0",

@@ -61,27 +75,85 @@ static struct netpoll np = {
 	.remote_port = 6666,
 	.remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
 };
-static int configured = 0;
 
 #define MAX_PRINT_CHUNK 1000
+#define CONFIG_SEPARATOR ";"
+
+static int add_target(char* target_config)
+{
+	int retval = 0;
+	static atomic_t target_count = ATOMIC_INIT(0);
+	struct netconsole_target *new_target;
+
+	new_target = kzalloc(sizeof(*new_target), GFP_KERNEL);
+	if (!new_target) {
+		printk(KERN_ERR "netconsole: kmalloc() failed!\n");
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	new_target->np = np;
+	if (netpoll_parse_options(&new_target->np, target_config)) {
+		printk(KERN_ERR "netconsole: can't parse config:%s\n",
+		       target_config);
+		kfree(new_target);
+		retval = -EINVAL;
+		goto out;
+	}
+	if (netpoll_setup(&new_target->np)) {
+		printk(KERN_ERR "netconsole: can't setup netpoll:%s\n",
+		       target_config);
+		kfree(new_target);
+		retval = -EINVAL;
+		goto out;
+	}
+
+	atomic_inc(&target_count);
+	new_target->id = atomic_read(&target_count);
+
+	printk(KERN_INFO "netconsole: add target: "
+	       "remote ip_addr=%d.%d.%d.%d remote port=%d\n",
+	       HIPQUAD(new_target->np.remote_ip), new_target->np.remote_port);
+
+	spin_lock(&target_list_lock);
+	list_add(&new_target->list, &target_list);
+	spin_unlock(&target_list_lock);
+
+ out:
+	return retval;
+}
+
+static void delete_target(struct netconsole_target *nt)
+{
+	spin_lock(&target_list_lock);
+	list_del(&nt->list);
+	spin_unlock(&target_list_lock);
+	netpoll_cleanup(&nt->np);
+	kfree(nt);
+}
 
 static void write_msg(struct console *con, const char *msg, unsigned int len)
 {
 	int frag, left;
 	unsigned long flags;
+	struct netconsole_target *target;
 
-	if (!np.dev)
+	if (list_empty(&target_list))
 		return;
 
 	local_irq_save(flags);
+	spin_lock(&target_list_lock);
 
 	for(left = len; left; ) {
 		frag = min(left, MAX_PRINT_CHUNK);
-		netpoll_send_udp(&np, msg, frag);
+		list_for_each_entry(target, &target_list, list) {
+			netpoll_send_udp(&target->np, msg, frag);
+		}
 		msg += frag;
 		left -= frag;
 	}
 
+	spin_unlock(&target_list_lock);
 	local_irq_restore(flags);
 }
 

@@ -91,39 +163,48 @@ static struct console netconsole = {
 	.write = write_msg
 };
 
+#ifndef MODULE
 static int __init option_setup(char *opt)
 {
-	configured = !netpoll_parse_options(&np, opt);
+	strncpy(config, opt, 256);
 	return 1;
 }
 
 __setup("netconsole=", option_setup);
+#endif
 
 static int __init init_netconsole(void)
 {
-	int err;
+	char *p;
+	char *tmp = config;
 
-	if(strlen(config))
-		option_setup(config);
+	register_console(&netconsole);
 
-	if(!configured) {
-		printk("netconsole: not configured, aborting\n");
+	if(!strlen(config)) {
+		printk(KERN_ERR "netconsole: not configured\n");
 		return 0;
 	}
+	while ((p = strsep(&tmp, CONFIG_SEPARATOR)) != NULL) {
+		if (add_target(p)) {
+			printk(KERN_ERR
+			       "netconsole: can't add target to netconsole\n");
+			cleanup_netconsole();
+			return -EINVAL;
+		}
+	}
 
-	err = netpoll_setup(&np);
-	if (err)
-		return err;
-
-	register_console(&netconsole);
 	printk(KERN_INFO "netconsole: network logging started\n");
 	return 0;
 }
 
 static void cleanup_netconsole(void)
 {
+	struct netconsole_target *nt, *tmp;
+
 	unregister_console(&netconsole);
-	netpoll_cleanup(&np);
+	list_for_each_entry_safe(nt, tmp, &target_list, list) {
+		delete_target(nt);
+	}
 }
 
 module_init(init_netconsole);
#4 lore raw

Re: [RFC][PATCH -mm take3 2/6][resend] support multiple logging

Quoted 4 lines · Keiichi KII

This patch contains the following changes for supporting multiple logging
agents.

+#define CONFIG_SEPARATOR ";"

CONFIG_* is reserved for configuration options. Since you use it in only one place just use semicolon directly.

author
#5 lore raw

Re: [RFC][PATCH -mm take3 2/6][resend] support multiple logging

Quoted 8 lines · Alexey Dobriyan
Quoted 4 lines · Keiichi KII

This patch contains the following changes for supporting multiple logging
agents.

+#define CONFIG_SEPARATOR ";"

CONFIG_* is reserved for configuration options. Since you use it in only one place just use semicolon directly.

Thank you for your reply.
I'm going to fix this when I send patches next time.

author
#6 lore raw

RFC PATCH 3/6 add interface for netconsole using sysfs

In reply to Keiichi KII

From: Keiichi KII <[email protected]>

This patch contains the following changes.

create a sysfs entry for netconsole in /sys/class/misc.
This entry has elements related to netconsole as follows.
You can change configuration of netconsole(writable attributes such as IP address, port number and so on) and check current configuration of netconsole.

-+- /sys/class/misc/
|-+- netconsole/

   |-+- port1/
   | |--- id          [r--r--r--]  unique port id
   | |--- local_ip    [rw-r--r--]  source IP to use, writable
   | |--- local_mac   [r--r--r--]  source MAC address
   | |--- local_port  [rw-r--r--]  source port number for UDP packets, writable
   | |--- remote_ip   [rw-r--r--]  port number for logging agent, writable
   | |--- remote_mac  [rw-r--r--]  MAC address for logging agent, writable
   | ---- remote_port [rw-r--r--]  IP address for logging agent, writable
   |--- port2/
   |--- port3/

...

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---

drivers/net/netconsole.c +220 -4
Index: linux-mm/drivers/net/netconsole.c
===================================================================
@@ -45,6 +45,8 @@
 #include <linux/sysrq.h>
 #include <linux/smp.h>
 #include <linux/netpoll.h>
+#include <linux/miscdevice.h>
+#include <linux/inet.h>
 
 MODULE_AUTHOR("Maintainer: Matt Mackall <[email protected]>");
 MODULE_DESCRIPTION("Console driver for network interfaces");

@@ -56,18 +58,215 @@ MODULE_PARM_DESC(netconsole, " netconsol
 
 struct netconsole_target {
 	struct list_head list;
+	struct kobject obj;
 	int id;
 	struct netpoll np;
 };
 
+#define MAX_PRINT_CHUNK 1000
+#define CONFIG_SEPARATOR ";"
+
+struct target_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct netconsole_target*, char*);
+	ssize_t (*store)(struct netconsole_target*, const char*,
+			 size_t count);
+};
+
 static int add_target(char* target_config);
+static int setup_target_sysfs(struct netconsole_target *nt);
 static void cleanup_netconsole(void);
 static void delete_target(struct netconsole_target *nt);
 
+static int miscdev_configured;
+
 static LIST_HEAD(target_list);
 
 static DEFINE_SPINLOCK(target_list_lock);
 
+static ssize_t show_id(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%d\n", nt->id);
+}
+
+static ssize_t show_local_port(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%d\n", nt->np.local_port);
+}
+
+static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%d\n", nt->np.remote_port);
+}
+
+static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%d.%d.%d.%d\n", HIPQUAD(nt->np.local_ip));
+}
+
+static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%d.%d.%d.%d\n", HIPQUAD(nt->np.remote_ip));
+}
+
+static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+		       nt->np.local_mac[0], nt->np.local_mac[1],
+		       nt->np.local_mac[2], nt->np.local_mac[3],
+		       nt->np.local_mac[4], nt->np.local_mac[5]);
+}
+
+static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+		       nt->np.remote_mac[0], nt->np.remote_mac[1],
+		       nt->np.remote_mac[2], nt->np.remote_mac[3],
+		       nt->np.remote_mac[4], nt->np.remote_mac[5]);
+}
+
+static ssize_t store_local_port(struct netconsole_target *nt, const char *buf,
+				size_t count)
+{
+	spin_lock(&target_list_lock);
+	nt->np.local_port = simple_strtol(buf, NULL, 10);
+	spin_unlock(&target_list_lock);
+
+	return count;
+}
+
+static ssize_t store_remote_port(struct netconsole_target *nt, const char *buf,
+				size_t count)
+{
+	spin_lock(&target_list_lock);
+	nt->np.remote_port = simple_strtol(buf, NULL, 10);
+	spin_unlock(&target_list_lock);
+
+	return count;
+}
+
+static ssize_t store_local_ip(struct netconsole_target *nt, const char *buf,
+			      size_t count)
+{
+	spin_lock(&target_list_lock);
+	nt->np.local_ip = ntohl(in_aton(buf));
+	spin_unlock(&target_list_lock);
+
+	return count;
+}
+
+static ssize_t store_remote_ip(struct netconsole_target *nt, const char *buf,
+			       size_t count)
+{
+	spin_lock(&target_list_lock);
+	nt->np.remote_ip = ntohl(in_aton(buf));
+	spin_unlock(&target_list_lock);
+
+	return count;
+}
+
+static ssize_t store_remote_mac(struct netconsole_target *nt, const char *buf,
+			       size_t count)
+{
+	unsigned char input_mac[ETH_ALEN] =
+		{0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+	const char *cur = buf;
+	int i = 0;
+
+	input_mac[i++] = simple_strtol(cur, NULL, 16);
+	while ((cur = strchr(cur, ':')) != NULL) {
+		cur++;
+		input_mac[i++] = simple_strtol(cur, NULL, 16);
+	}
+	if (i != ETH_ALEN)
+		return -EINVAL;
+	spin_lock(&target_list_lock);
+	memcpy(nt->np.remote_mac, input_mac, ETH_ALEN);
+	spin_unlock(&target_list_lock);
+
+	return count;
+}
+
+#define NETCON_CLASS_ATTR(_name, _mode, _show, _store) \
+struct target_attr target_attr_##_name = \
+                           __ATTR(_name, _mode, _show, _store)
+
+static NETCON_CLASS_ATTR(id, S_IRUGO, show_id, NULL);
+static NETCON_CLASS_ATTR(local_port, S_IRUGO | S_IWUSR,
+			 show_local_port, store_local_port);
+static NETCON_CLASS_ATTR(remote_port, S_IRUGO | S_IWUSR,
+			 show_remote_port, store_remote_port);
+static NETCON_CLASS_ATTR(local_ip, S_IRUGO | S_IWUSR,
+			 show_local_ip, store_local_ip);
+static NETCON_CLASS_ATTR(remote_ip, S_IRUGO | S_IWUSR,
+			 show_remote_ip, store_remote_ip);
+static NETCON_CLASS_ATTR(local_mac, S_IRUGO, show_local_mac, NULL);
+static NETCON_CLASS_ATTR(remote_mac, S_IRUGO | S_IWUSR,
+			 show_remote_mac, store_remote_mac);
+
+static struct attribute *target_attrs[] = {
+	&target_attr_id.attr,
+	&target_attr_local_port.attr,
+	&target_attr_remote_port.attr,
+	&target_attr_local_ip.attr,
+	&target_attr_remote_ip.attr,
+	&target_attr_local_mac.attr,
+	&target_attr_remote_mac.attr,
+	NULL
+};
+
+static ssize_t show_target_attr(struct kobject *kobj,
+				    struct attribute *attr,
+				    char *buffer)
+{
+	struct target_attr *na =
+		container_of(attr, struct target_attr, attr);
+	struct netconsole_target * nt =
+		container_of(kobj, struct netconsole_target, obj);
+	if (na->show)
+		return na->show(nt, buffer);
+	else
+		return -EIO;
+}
+
+static ssize_t store_target_attr(struct kobject *kobj,
+				     struct attribute *attr,
+				     const char *buffer, size_t count)
+{
+	struct target_attr *na =
+		container_of(attr, struct target_attr, attr);
+	struct netconsole_target *nt =
+		container_of(kobj, struct netconsole_target, obj);
+	if (na->store)
+		return na->store(nt, buffer, count);
+	else
+		return -EIO;
+}
+
+static void release_target(struct kobject *kobj)
+{
+	struct netconsole_target *nt =
+		container_of(kobj, struct netconsole_target, obj);
+
+	delete_target(nt);
+}
+
+static struct sysfs_ops target_sysfs_ops = {
+	.show = show_target_attr,
+	.store = store_target_attr
+};
+
+static struct kobj_type target_ktype = {
+	.release = release_target,
+	.sysfs_ops = &target_sysfs_ops,
+	.default_attrs = target_attrs,
+};
+
+static struct miscdevice netconsole_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "netconsole",
+};
+
 static struct netpoll np = {
 	.name = "netconsole",
 	.dev_name = "eth0",

@@ -76,9 +275,6 @@ static struct netpoll np = {
 	.remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
 };
 
-#define MAX_PRINT_CHUNK 1000
-#define CONFIG_SEPARATOR ";"
-
 static int add_target(char* target_config)
 {
 	int retval = 0;

@@ -119,10 +315,19 @@ static int add_target(char* target_confi
 	list_add(&new_target->list, &target_list);
 	spin_unlock(&target_list_lock);
 
+	retval = setup_target_sysfs(new_target);
  out:
 	return retval;
 }
 
+static int setup_target_sysfs(struct netconsole_target *nt)
+{
+	kobject_set_name(&nt->obj, "port%d", nt->id);
+	nt->obj.parent = &netconsole_miscdev.this_device->kobj;
+	nt->obj.ktype = &target_ktype;
+	return kobject_register(&nt->obj);
+}
+
 static void delete_target(struct netconsole_target *nt)
 {
 	spin_lock(&target_list_lock);

@@ -178,6 +383,15 @@ static int __init init_netconsole(void)
 	char *p;
 	char *tmp = config;
 
+	if (misc_register(&netconsole_miscdev)) {
+		printk(KERN_ERR
+		       "netconsole: failed to register misc device for "
+		       "name = %s, id = %d\n",
+		       netconsole_miscdev.name, netconsole_miscdev.minor);
+		return -EIO;
+	} else
+		miscdev_configured = 1;
+
 	register_console(&netconsole);
 
 	if(!strlen(config)) {

@@ -203,8 +417,10 @@ static void cleanup_netconsole(void)
 
 	unregister_console(&netconsole);
 	list_for_each_entry_safe(nt, tmp, &target_list, list) {
-		delete_target(nt);
+		kobject_unregister(&nt->obj);
 	}
+	if (miscdev_configured)
+		misc_deregister(&netconsole_miscdev);
 }
 
 module_init(init_netconsole);
author
#7 lore raw

RFC PATCH 4/6 using symlink for the net_device

In reply to Keiichi KII

From: Keiichi KII <[email protected]>

We use symbolic link for net_device.
The link in sysfs represents the corresponding network etherdevice.

-+- /sys/class/misc/

 |-+- netconsole/
 |-+- port1/
 | |--- id             [r--r--r--]  id
 | |--- net:<net_dev>  [rw-r--r--]  net_dev: eth0,eth1,...
 | ...
 |--- port2/

...

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---

drivers/net/netconsole.c +71 -1
Index: linux-mm/drivers/net/netconsole.c
===================================================================
@@ -77,6 +77,9 @@ static int add_target(char* target_confi
 static int setup_target_sysfs(struct netconsole_target *nt);
 static void cleanup_netconsole(void);
 static void delete_target(struct netconsole_target *nt);
+static char* make_netdev_class_name(char *netdev_name);
+static int netconsole_event(struct notifier_block *this, unsigned long event,
+			    void *ptr);
 
 static int miscdev_configured;
 

@@ -275,6 +278,10 @@ static struct netpoll np = {
 	.remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
 };
 
+static struct notifier_block netconsole_notifier = {
+	.notifier_call = netconsole_event,
+};
+
 static int add_target(char* target_config)
 {
 	int retval = 0;

@@ -322,10 +329,20 @@ static int add_target(char* target_confi
 
 static int setup_target_sysfs(struct netconsole_target *nt)
 {
+	int retval = 0;
+	char *name;
+
 	kobject_set_name(&nt->obj, "port%d", nt->id);
 	nt->obj.parent = &netconsole_miscdev.this_device->kobj;
 	nt->obj.ktype = &target_ktype;
-	return kobject_register(&nt->obj);
+	retval = kobject_register(&nt->obj);
+	name = make_netdev_class_name(nt->np.dev_name);
+	if (IS_ERR(name))
+		return PTR_ERR(name);
+	retval = sysfs_create_link(&nt->obj, &nt->np.dev->dev.kobj, name);
+	kfree(name);
+
+	return retval;
 }
 
 static void delete_target(struct netconsole_target *nt)

@@ -337,6 +354,57 @@ static void delete_target(struct netcons
 	kfree(nt);
 }
 
+static char* make_netdev_class_name(char *netdev_name)
+{
+	int size;
+	char *name;
+	char *netdev_class_prefix = "net:";
+
+	size = strlen(netdev_class_prefix) + strlen(netdev_name) + 1;
+	name = kmalloc(size, GFP_KERNEL);
+	if (!name) {
+		printk(KERN_ERR "netconsole: kmalloc() failed!\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	strcpy(name, netdev_class_prefix);
+	strcat(name, netdev_name);
+
+	return name;
+}
+
+static int netconsole_event(struct notifier_block *this, unsigned long event,
+			    void *ptr)
+{
+	int error = 0;
+	char *old_link_name = NULL, *new_link_name = NULL;
+	struct netconsole_target *nt;
+	struct net_device *dev = ptr;
+
+	if (event == NETDEV_CHANGENAME) {
+		spin_lock(&target_list_lock);
+		list_for_each_entry(nt, &target_list, list) {
+			if (nt->np.dev != dev)
+				continue;
+			new_link_name = make_netdev_class_name(dev->name);
+			old_link_name =
+				make_netdev_class_name(nt->np.dev_name);
+			sysfs_remove_link(&nt->obj, old_link_name);
+			error = sysfs_create_link(&nt->obj,
+						  &nt->np.dev->dev.kobj,
+						  new_link_name);
+			if (error)
+				printk(KERN_ERR "can't create link: %s\n",
+				       new_link_name);
+			strcpy(nt->np.dev_name, dev->name);
+			kfree(new_link_name);
+			kfree(old_link_name);
+		}
+		spin_unlock(&target_list_lock);
+	}
+
+	return NOTIFY_DONE;
+}
+
 static void write_msg(struct console *con, const char *msg, unsigned int len)
 {
 	int frag, left;

@@ -393,6 +461,7 @@ static int __init init_netconsole(void)
 		miscdev_configured = 1;
 
 	register_console(&netconsole);
+	register_netdevice_notifier(&netconsole_notifier);
 
 	if(!strlen(config)) {
 		printk(KERN_ERR "netconsole: not configured\n");

@@ -416,6 +485,7 @@ static void cleanup_netconsole(void)
 	struct netconsole_target *nt, *tmp;
 
 	unregister_console(&netconsole);
+	unregister_netdevice_notifier(&netconsole_notifier);
 	list_for_each_entry_safe(nt, tmp, &target_list, list) {
 		kobject_unregister(&nt->obj);
 	}
author
#8 lore raw

RFC PATCH 5/6 switch function of netpoll

In reply to Keiichi KII

From: Keiichi KII <[email protected]>

This patch contains switch function of netpoll.

If "enabled" attribute of certain port is '1', this port is used and the configurations of this port are uable to change.

If "enabled" attribute of certain port is '0', this port isn't used and the configurations of this port are able to change.

-+- /sys/class/misc/
|-+- netconsole/

  |-+- port1/
  | |--- id          [r--r--r--]  id
  | |--- enabled     [rw-r--r--]  0: disable 1: enable, writable
  | ...
  |--- port2/

...

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---

drivers/net/netconsole.c +55 -1
Index: linux-2.6.19.5/drivers/net/netconsole.c
===================================================================
@@ -60,6 +60,7 @@ struct netconsole_target {
 	struct list_head list;
 	struct kobject obj;
 	int id;
+	int enabled;
 	struct netpoll np;
 };
 

@@ -128,10 +129,19 @@ static ssize_t show_remote_mac(struct ne
 		       nt->np.remote_mac[4], nt->np.remote_mac[5]);
 }
 
+static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
+{
+	return sprintf(buf, "%d\n", nt->enabled);
+}
+
 static ssize_t store_local_port(struct netconsole_target *nt, const char *buf,
 				size_t count)
 {
 	spin_lock(&target_list_lock);
+	if (nt->enabled) {
+		spin_unlock(&target_list_lock);
+		return -EINVAL;
+	}
 	nt->np.local_port = simple_strtol(buf, NULL, 10);
 	spin_unlock(&target_list_lock);
 

@@ -142,6 +152,10 @@ static ssize_t store_remote_port(struct 
 				size_t count)
 {
 	spin_lock(&target_list_lock);
+	if (nt->enabled) {
+		spin_unlock(&target_list_lock);
+		return -EINVAL;
+	}
 	nt->np.remote_port = simple_strtol(buf, NULL, 10);
 	spin_unlock(&target_list_lock);
 

@@ -152,6 +166,10 @@ static ssize_t store_local_ip(struct net
 			      size_t count)
 {
 	spin_lock(&target_list_lock);
+	if (nt->enabled) {
+		spin_unlock(&target_list_lock);
+		return -EINVAL;
+	}
 	nt->np.local_ip = ntohl(in_aton(buf));
 	spin_unlock(&target_list_lock);
 

@@ -162,6 +180,10 @@ static ssize_t store_remote_ip(struct ne
 			       size_t count)
 {
 	spin_lock(&target_list_lock);
+	if (nt->enabled) {
+		spin_unlock(&target_list_lock);
+		return -EINVAL;
+	}
 	nt->np.remote_ip = ntohl(in_aton(buf));
 	spin_unlock(&target_list_lock);
 

@@ -184,12 +206,39 @@ static ssize_t store_remote_mac(struct n
 	if (i != ETH_ALEN)
 		return -EINVAL;
 	spin_lock(&target_list_lock);
+	if (nt->enabled) {
+		spin_unlock(&target_list_lock);
+		return -EINVAL;
+	}
 	memcpy(nt->np.remote_mac, input_mac, ETH_ALEN);
 	spin_unlock(&target_list_lock);
 
 	return count;
 }
 
+static ssize_t store_enabled(struct netconsole_target *nt, const char *buf,
+			    size_t count)
+{
+	int enabled = 0;
+
+	if (count >= 2 && (count != 2 || buf[count - 1] != '\n')) {
+		printk(KERN_ERR "netconsole: invalid argument: %s\n", buf);
+		return -EINVAL;
+	} else if (strncmp(buf, "1", 1) == 0) {
+		enabled = 1;
+	} else if(strncmp(buf, "0", 1) == 0) {
+		enabled = 0;
+	} else {
+		printk(KERN_ERR "netconsole: invalid argument: %s\n", buf);
+		return -EINVAL;
+	}
+	spin_lock(&target_list_lock);
+	nt->enabled = enabled;
+	spin_unlock(&target_list_lock);
+
+	return count;
+}
+
 #define NETCON_CLASS_ATTR(_name, _mode, _show, _store) \
 struct target_attr target_attr_##_name = \
                            __ATTR(_name, _mode, _show, _store)

@@ -206,6 +255,8 @@ static NETCON_CLASS_ATTR(remote_ip, S_IR
 static NETCON_CLASS_ATTR(local_mac, S_IRUGO, show_local_mac, NULL);
 static NETCON_CLASS_ATTR(remote_mac, S_IRUGO | S_IWUSR,
 			 show_remote_mac, store_remote_mac);
+static NETCON_CLASS_ATTR(enabled, S_IRUGO | S_IWUSR,
+			 show_enabled, store_enabled);
 
 static struct attribute *target_attrs[] = {
 	&target_attr_id.attr,

@@ -215,6 +266,7 @@ static struct attribute *target_attrs[] 
 	&target_attr_remote_ip.attr,
 	&target_attr_local_mac.attr,
 	&target_attr_remote_mac.attr,
+	&target_attr_enabled.attr,
 	NULL
 };
 

@@ -313,6 +365,7 @@ static int add_target(char* target_confi
 
 	atomic_inc(&target_count);
 	new_target->id = atomic_read(&target_count);
+	new_target->enabled = 1;
 
 	printk(KERN_INFO "netconsole: add target: "
 	       "remote ip_addr=%d.%d.%d.%d remote port=%d\n",

@@ -420,7 +473,8 @@ static void write_msg(struct console *co
 	for(left = len; left; ) {
 		frag = min(left, MAX_PRINT_CHUNK);
 		list_for_each_entry(target, &target_list, list) {
-			netpoll_send_udp(&target->np, msg, frag);
+			if (target->enabled)
+				netpoll_send_udp(&target->np, msg, frag);
 		}
 		msg += frag;
 		left -= frag;
author
#9 lore raw

RFC PATCH 6/6 add ioctls for adding/removing target

In reply to Keiichi KII

From: Keiichi KII <[email protected]>

We add ioctls for adding/removing target.
If we use NETCONSOLE_ADD_TARGET ioctl,
we can dynamically add netconsole target.
If we use NETCONSOLE_REMOVE_TARGET ioctl,
we can dynamically remoe netconsole target.

We attach a sample program for ioctl.

Signed-off-by Keiichi KII <[email protected]>
Signed-off-by Takayoshi Kochi <[email protected]>

---
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stropts.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <linux/if_ether.h>

#define NETCONSOLE_DEV_NAME "/dev/netconsole"

struct command {
        char *name;
        char *options;
        int (*handle_command)(struct command* command,
                              int argc, char* argv[]);
        void (*usage)(char *msg);

extern char *optarg;

static void generic_usage(char *msg) {
        fprintf(stderr, "Usage  : netconfig command [option] [args]\n");
        fprintf(stderr, "command: add remove help\n");
        exit(-1);
                        break;
                case 's':
                        address = inet_addr(optarg);
                        if (address == -1)
                                (*command->usage)("invlid IP address!\n");
                        req.local_ip = address;
                        break;
                case 'h':
                default:
                        (*command->usage)(NULL);
                }
        }
        argc -= optind;
                if (i != ETH_ALEN)
                        (*command->usage)("Invalid MAC address!\n");
                memcpy(req.remote_mac, mac, ETH_ALEN);

        fd = open(NETCONSOLE_DEV_NAME, O_RDWR);
        if (fd < 0) {
                fprintf(stderr, "cannot open device" NETCONSOLE_DEV_NAME "\n");
                return -1;
        exit(-1);

static int handle_command_remove(struct command *command,
int argc, char** argv)
{

        while ((ch = getopt(argc, argv, command->options)) != -1) {
                switch (ch) {
                case 'h':
                default:
                        (*command->usage)(NULL);
                }
        }
        argc -= optind;

        if (argc != 1)

        id = atoi(argv[0]);
        fd = open(NETCONSOLE_DEV_NAME, O_RDWR);
        if (fd < 0) {
                fprintf(stderr, "can't open device " NETCONSOLE_DEV_NAME "\n");
                return -1;
        }
        if(ioctl(fd, NETCON_REMOVE_TARGET, &id) != 0)
                perror("remove");

        return 0;
static void usage_remove(char *msg) {
        fprintf(stderr, "Usage  : netconfig remove id\n");
        exit(-1);

static int handle_command_help(struct command *command,

                               int argc, char** argv) {

        return 0;
static void usage_help(char *msg) {
        generic_usage(NULL);
                        break;
                }
        }

        if (command == NULL)
                generic_usage(NULL);
        argc--;
        argv++;

        if (command->handle_command)
                (*command->handle_command)(command, argc, argv);
        else {
                fprintf(stderr, "function handle_command() isn't set.");
                exit(-1);
        }
        return 0;
}
fs/compat_ioctl.c +2 -0
Index: linux-mm/fs/compat_ioctl.c
===================================================================
@@ -117,6 +117,8 @@
 #include <linux/dvb/video.h>
 #include <linux/lp.h>
 
+#include <linux/netconsole.h>
+
 static int do_ioctl32_pointer(unsigned int fd, unsigned int cmd,
 			      unsigned long arg, struct file *f)
 {
include/linux/compat_ioctl.h +3 -0
Index: linux-mm/include/linux/compat_ioctl.h
===================================================================
@@ -828,3 +828,6 @@ COMPATIBLE_IOCTL(VIDEO_GET_NAVI)
 COMPATIBLE_IOCTL(VIDEO_SET_ATTRIBUTES)
 COMPATIBLE_IOCTL(VIDEO_GET_SIZE)
 COMPATIBLE_IOCTL(VIDEO_GET_FRAME_RATE)
+/* netconsole */
+COMPATIBLE_IOCTL(NETCON_ADD_TARGET)
+ULONG_IOCTL(NETCON_REMOVE_TARGET)
include/linux/netconsole.h new file +18 -0
Index: linux-mm/include/linux/netconsole.h
===================================================================
@@ -0,0 +1,18 @@
+#ifndef __NETCONSOLE_H
+#define __NETCONSOLE_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+struct netconsole_request {
+	__u32 id;
+	__u8 netdev_name[IFNAMSIZ];
+	__u8 remote_mac[ETH_ALEN];
+	__u32 local_ip, remote_ip;
+	__u16 local_port, remote_port;
+};
+
+#define NETCON_ADD_TARGET _IOW(0xAE, 4, struct netconsole_request)
+#define NETCON_REMOVE_TARGET _IOW(0xAE, 5, int)
+
+#endif /* __NETCONSOLE_H */
drivers/net/netconsole.c +64 -0

85 lines not on this page · raw message

#10 lore raw

Re: [RFC][PATCH -mm take3 6/6][resend] add ioctls for adding/removing target

Quoted 55 lines · Keiichi KII

We add ioctls for adding/removing target. If we use NETCONSOLE_ADD_TARGET ioctl, we can dynamically add netconsole target. If we use NETCONSOLE_REMOVE_TARGET ioctl, we can dynamically remoe netconsole target.

We attach a sample program for ioctl.

drivers/net/netconsole.c +47 -0
+static int netconsole_ioctl(struct inode *inode, struct file *file,
+			    unsigned int cmd, unsigned long arg)
+{
+	int id, count;
+	char config[256];
+	char *cur;
+	struct netconsole_request req;
+	struct netconsole_target *nt, *tmp;
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	case NETCON_ADD_TARGET:
+		printk(KERN_INFO "netconsole: cmd=NETCON_ADD_TARGET\n");
+		if (copy_from_user(&req, argp, sizeof(req)))
+			return -EFAULT;
+		cur = config;
+		count = sprintf(cur, "%d@", req.local_port);
+		cur += count;
+		if (req.local_ip)
+			count = sprintf(cur, "%d.%d.%d.%d/",
+					NIPQUAD(req.local_ip));
+		else
+			count = sprintf(cur, "/");
+		cur += count;
+		count = sprintf(cur, "%s,", req.netdev_name);
+		cur += count;
+		count = sprintf(cur, "%d@", req.remote_port);
+		cur += count;
+		count = sprintf(cur, "%d.%d.%d.%d/",
+				NIPQUAD(req.remote_ip));
+		cur += count;
+		count = sprintf(cur, "%02x:%02x:%02x:%02x:%02x:%02x",
+				req.remote_mac[0], req.remote_mac[1],
+				req.remote_mac[2], req.remote_mac[3],
+				req.remote_mac[4], req.remote_mac[5]);
+		printk(KERN_INFO "count = %d config=[%s]\n", count, config);
+		if (add_target(config))
+			return -EINVAL;
+		break;
+	case NETCON_REMOVE_TARGET:
+		printk(KERN_INFO "netconsole: cmd=NETCON_REMOVE_TARGET\n");
+		if (copy_from_user(&id, argp, sizeof(int)))
+			return -EFAULT;
+		printk(KERN_INFO "netconsole: id=%d\n", id);
+		list_for_each_entry_safe(nt, tmp, &target_list, list) {
+			if (nt->id == id) {
+				kobject_unregister(&nt->obj);

drivers/net/netconsole.c static void release_target(struct kobjec · line 366

Quoted 10 lines
drivers/net/netconsole.c +10 -0
+				break;
+			}
+		}
+		break;
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}

If you go with misc device, then implement ->write method so you, say, do

echo "add [same format as with module parameter]" >/dev/netconsole

and avoid all that additional programs and ioctls.

#11 lore raw

Re: [RFC][PATCH -mm take3 6/6][resend] add ioctls for adding/removing target

Since these are network device related ioctl's it might be clearer (and easier) to use network device (struct ifreq) style ioctl's.

Signature · 1 line
Stephen Hemminger <[email protected]>
author
#12 lore raw

Re: [RFC][PATCH -mm take3 6/6][resend] add ioctls for adding/removing target

In reply to Keiichi KII

Sorry, I sent the incomplete sample program.
So, I send the complete one again.
Any comments welcom.

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stropts.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <linux/if_ether.h>
#include <linux/netconsole.h>

#define NETCONSOLE_DEV_NAME "/dev/netconsole" #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

struct command {
	char *name;
	char *options;
	int (*handle_command)(struct command* command,
			      int argc, char* argv[]);
	void (*usage)(char *msg);
};

extern char *optarg;
extern int opterr, optind, errno;

static void generic_usage(char *msg) {
	fprintf(stderr, "Usage  : netconfig command [option] [args]\n");
	fprintf(stderr, "command: add remove help\n");
	exit(-1);
}

static int handle_command_add(struct command* command, int argc, char** argv)

{
	int i, fd, ch;
	unsigned int address;
	unsigned char mac[ETH_ALEN];
	struct netconsole_request req = {
		.netdev_name = "eth0",
		.local_port = 6665,
		.remote_port = 6666,
		.remote_mac = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
	};

	while ((ch = getopt(argc, argv, command->options)) != -1) {
		switch (ch) {
		case 'p':
			req.local_port = atoi(optarg);
			break;
		case 's':
			address = inet_addr(optarg);
			if (address == -1)
				(*command->usage)("invlid IP address!\n");
			req.local_ip = address;
			break;
		case 'h':
		default:
			(*command->usage)(NULL);
		}
	}
	argc -= optind;
	argv += optind;

	if (argc < 3 || argc > 4)
		(*command->usage)(NULL);

	memcpy(req.netdev_name, argv[0], IFNAMSIZ);
	address = inet_addr(argv[1]);
	if (address == -1)
		(*command->usage)("invlid IP address!\n");
	req.remote_ip = address;
	req.remote_port = atoi(argv[2]);
	if (argc == 4) {
		i = 0;
		mac[i++] = strtol(argv[3], NULL, 16);
		while ((argv[3] = strchr(argv[3], ':')) != NULL) {
			argv[3]++;
			mac[i++] = strtol(argv[3], NULL, 16);
		}
		if (i != ETH_ALEN)
			(*command->usage)("Invalid MAC address!\n");
		memcpy(req.remote_mac, mac, ETH_ALEN);
	}

	fd = open(NETCONSOLE_DEV_NAME, O_RDWR);
	if (fd < 0) {
		fprintf(stderr, "cannot open device" NETCONSOLE_DEV_NAME "\n");
		return -1;
	}

	if(ioctl(fd, NETCON_ADD_TARGET, &req) != 0)
		perror("add");
	close(fd);

	return 0;
}

static void usage_add(char *msg)

{
	if (msg != NULL)
		fprintf(stderr, "%s", msg);
	fprintf(stderr, "Usage  : netconfig add [-options] dev_name remote_ip "
		"remote_port [remote_mac]\n");
	fprintf(stderr, "options:\n");
	fprintf(stderr, "        -p local_port     :local port number\n");
	fprintf(stderr, "        -s local_up       :local IP address\n");
	exit(-1);
}

static int handle_command_remove(struct command *command,
int argc, char** argv)

{
	int fd, id, ch;

	while ((ch = getopt(argc, argv, command->options)) != -1) {
		switch (ch) {
		case 'h':
		default:
			(*command->usage)(NULL);
		}
	}
	argc -= optind;
	argv += optind;

	if (argc != 1)
		(*command->usage)(NULL);

	id = atoi(argv[0]);
	fd = open(NETCONSOLE_DEV_NAME, O_RDWR);
	if (fd < 0) {
		fprintf(stderr, "can't open device " NETCONSOLE_DEV_NAME "\n");
		return -1;
	}
	if(ioctl(fd, NETCON_REMOVE_TARGET, &id) != 0)
		perror("remove");
	close(fd);

	return 0;
}
static void usage_remove(char *msg) {
	fprintf(stderr, "Usage  : netconfig remove id\n");
	exit(-1);
}

static int handle_command_help(struct command *command,

			       int argc, char** argv) {
	(*command->usage)(NULL);

	return 0;
}
static void usage_help(char *msg) {
	generic_usage(NULL);
}
static struct command s_commands[] = {
	{"add", "hp:s:", handle_command_add, usage_add},
	{"remove", "hp:", handle_command_remove, usage_remove},
	{"help", NULL, handle_command_help, usage_help},
};
int main(int argc, char* argv[]) {
	int i;
	struct command *command = NULL;

	for(i = 0; i < ARRAY_SIZE(s_commands); i++) {
		if (argc <= 1)
			break;
		if (strcmp(s_commands[i].name, argv[1]) == 0) {
			command = &s_commands[i];
			break;
		}
	}

	if (command == NULL)
		generic_usage(NULL);
	argc--;
	argv++;

	if (command->handle_command)
		(*command->handle_command)(command, argc, argv);
	else {
		fprintf(stderr, "function handle_command() isn't set.");
		exit(-1);
	}
	return 0;
}