diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/netconsole.c | 171 |
1 files changed, 131 insertions, 40 deletions
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 55570988250..458c4d674a9 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -62,44 +62,93 @@ static int __init option_setup(char *opt) __setup("netconsole=", option_setup); #endif /* MODULE */ +/* Linked list of all configured targets */ +static LIST_HEAD(target_list); + +/* This needs to be a spinlock because write_msg() cannot sleep */ +static DEFINE_SPINLOCK(target_list_lock); + /** * struct netconsole_target - Represents a configured netconsole target. + * @list: Links this target into the target_list. * @np: The netpoll structure for this target. */ struct netconsole_target { + struct list_head list; struct netpoll np; }; -static struct netconsole_target default_target = { - .np = { - .name = "netconsole", - .dev_name = "eth0", - .local_port = 6665, - .remote_port = 6666, - .remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, - }, -}; +/* Allocate new target and setup netpoll for it */ +static struct netconsole_target *alloc_target(char *target_config) +{ + int err = -ENOMEM; + struct netconsole_target *nt; + + /* Allocate and initialize with defaults */ + nt = kzalloc(sizeof(*nt), GFP_KERNEL); + if (!nt) { + printk(KERN_ERR "netconsole: failed to allocate memory\n"); + goto fail; + } + + nt->np.name = "netconsole"; + strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ); + nt->np.local_port = 6665; + nt->np.remote_port = 6666; + memset(nt->np.remote_mac, 0xff, ETH_ALEN); + + /* Parse parameters and setup netpoll */ + err = netpoll_parse_options(&nt->np, target_config); + if (err) + goto fail; + + err = netpoll_setup(&nt->np); + if (err) + goto fail; + + return nt; + +fail: + kfree(nt); + return ERR_PTR(err); +} + +/* Cleanup netpoll for given target and free it */ +static void free_target(struct netconsole_target *nt) +{ + netpoll_cleanup(&nt->np); + kfree(nt); +} /* Handle network interface device notifications */ static int netconsole_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) { + unsigned long flags; + struct netconsole_target *nt; struct net_device *dev = ptr; - struct netconsole_target *nt = &default_target; - if (nt->np.dev == dev) { - switch (event) { - case NETDEV_CHANGEADDR: - memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN); - break; + if (!(event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME)) + goto done; + + spin_lock_irqsave(&target_list_lock, flags); + list_for_each_entry(nt, &target_list, list) { + if (nt->np.dev == dev) { + switch (event) { + case NETDEV_CHANGEADDR: + memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN); + break; - case NETDEV_CHANGENAME: - strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ); - break; + case NETDEV_CHANGENAME: + strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ); + break; + } } } + spin_unlock_irqrestore(&target_list_lock, flags); +done: return NOTIFY_DONE; } @@ -111,18 +160,32 @@ static void write_msg(struct console *con, const char *msg, unsigned int len) { int frag, left; unsigned long flags; - struct netconsole_target *nt = &default_target; - - if (netif_running(nt->np.dev)) { - local_irq_save(flags); - for (left = len; left;) { - frag = min(left, MAX_PRINT_CHUNK); - netpoll_send_udp(&nt->np, msg, frag); - msg += frag; - left -= frag; + struct netconsole_target *nt; + const char *tmp; + + /* Avoid taking lock and disabling interrupts unnecessarily */ + if (list_empty(&target_list)) + return; + + spin_lock_irqsave(&target_list_lock, flags); + list_for_each_entry(nt, &target_list, list) { + if (netif_running(nt->np.dev)) { + /* + * We nest this inside the for-each-target loop above + * so that we're able to get as much logging out to + * at least one target if we die inside here, instead + * of unnecessarily keeping all targets in lock-step. + */ + tmp = msg; + for (left = len; left;) { + frag = min(left, MAX_PRINT_CHUNK); + netpoll_send_udp(&nt->np, tmp, frag); + tmp += frag; + left -= frag; + } } - local_irq_restore(flags); } + spin_unlock_irqrestore(&target_list_lock, flags); } static struct console netconsole = { @@ -134,39 +197,67 @@ static struct console netconsole = { static int __init init_netconsole(void) { int err = 0; - struct netconsole_target *nt = &default_target; + struct netconsole_target *nt, *tmp; + unsigned long flags; + char *target_config; + char *input = config; - if (!strnlen(config, MAX_PARAM_LENGTH)) { + if (!strnlen(input, MAX_PARAM_LENGTH)) { printk(KERN_INFO "netconsole: not configured, aborting\n"); goto out; } - err = netpoll_parse_options(&nt->np, config); - if (err) - goto out; - - err = netpoll_setup(&nt->np); - if (err) - goto out; + while ((target_config = strsep(&input, ";"))) { + nt = alloc_target(target_config); + if (IS_ERR(nt)) { + err = PTR_ERR(nt); + goto fail; + } + spin_lock_irqsave(&target_list_lock, flags); + list_add(&nt->list, &target_list); + spin_unlock_irqrestore(&target_list_lock, flags); + } err = register_netdevice_notifier(&netconsole_netdev_notifier); if (err) - goto out; + goto fail; register_console(&netconsole); printk(KERN_INFO "netconsole: network logging started\n"); out: return err; + +fail: + printk(KERN_ERR "netconsole: cleaning up\n"); + + /* + * Remove all targets and destroy them. Skipping the list + * lock is safe here, and netpoll_cleanup() will sleep. + */ + list_for_each_entry_safe(nt, tmp, &target_list, list) { + list_del(&nt->list); + free_target(nt); + } + + return err; } static void __exit cleanup_netconsole(void) { - struct netconsole_target *nt = &default_target; + struct netconsole_target *nt, *tmp; unregister_console(&netconsole); unregister_netdevice_notifier(&netconsole_netdev_notifier); - netpoll_cleanup(&nt->np); + + /* + * Remove all targets and destroy them. Skipping the list + * lock is safe here, and netpoll_cleanup() will sleep. + */ + list_for_each_entry_safe(nt, tmp, &target_list, list) { + list_del(&nt->list); + free_target(nt); + } } module_init(init_netconsole); |