Re: [RFC][PATCH -mm take4 6/6] add ioctls for adding/removing target

Andrew Morton
2007-04-20T04:16:50Z

On Wed, 18 Apr 2007 21:14:55 +0900 Keiichi KII <k-keiichi@bx.jp.nec.com> wrote:

> From: Keiichi KII <k-keiichi@bx.jp.nec.com>
>
> 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.
>
> ...
>
> --- mm.orig/drivers/net/netconsole.c
> +++ mm/drivers/net/netconsole.c
> @@ -47,6 +47,7 @@
> #include <linux/netpoll.h>
> #include <linux/miscdevice.h>
> #include <linux/inet.h>
> +#include <linux/netconsole.h>
>
> MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
> MODULE_DESCRIPTION("Console driver for network interfaces");
> @@ -313,6 +314,64 @@ static void release_target(struct kobjec
> remove_target(nt);
> }
>
> +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);
> + break;
> + }
> + }
> + break;
> + default:
> + return -ENOTTY;
> + }
> +
> + return 0;
> +}
> +
> static struct sysfs_ops target_sysfs_ops = {
> .show = show_target_attr,
> .store = store_target_attr
> @@ -324,9 +383,14 @@ static struct kobj_type target_ktype = {
> .default_attrs = target_attrs,
> };
>
> +static struct file_operations miscdev_fops = {
> + .ioctl = netconsole_ioctl,
> +};
> +
> static struct miscdevice netconsole_miscdev = {
> .minor = MISC_DYNAMIC_MINOR,
> .name = "netconsole",
> + .fops = &miscdev_fops,
> };
>
> static struct notifier_block netconsole_notifier = {

We'll need to wake up the net guys to get an opinion here. Using an
ioctl() against a miscdev is rather untypical for networking. I'd expect
they'd prefer to see a netlink-based interface to userspace.