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path: root/drivers/net/netconsole.c
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Diffstat (limited to 'drivers/net/netconsole.c')
-rw-r--r--drivers/net/netconsole.c169
1 files changed, 151 insertions, 18 deletions
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 15731d1db918..97f3acd44798 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -79,6 +79,12 @@ static LIST_HEAD(target_list);
/* This needs to be a spinlock because write_msg() cannot sleep */
static DEFINE_SPINLOCK(target_list_lock);
+/*
+ * Console driver for extended netconsoles. Registered on the first use to
+ * avoid unnecessarily enabling ext message formatting.
+ */
+static struct console netconsole_ext;
+
/**
* struct netconsole_target - Represents a configured netconsole target.
* @list: Links this target into the target_list.
@@ -104,14 +110,15 @@ struct netconsole_target {
#ifdef CONFIG_NETCONSOLE_DYNAMIC
struct config_item item;
#endif
- int enabled;
- struct mutex mutex;
+ bool enabled;
+ bool extended;
struct netpoll np;
};
#ifdef CONFIG_NETCONSOLE_DYNAMIC
static struct configfs_subsystem netconsole_subsys;
+static DEFINE_MUTEX(dynamic_netconsole_mutex);
static int __init dynamic_netconsole_init(void)
{
@@ -185,9 +192,13 @@ static struct netconsole_target *alloc_param_target(char *target_config)
strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
nt->np.local_port = 6665;
nt->np.remote_port = 6666;
- mutex_init(&nt->mutex);
eth_broadcast_addr(nt->np.remote_mac);
+ if (*target_config == '+') {
+ nt->extended = true;
+ target_config++;
+ }
+
/* Parse parameters and setup netpoll */
err = netpoll_parse_options(&nt->np, target_config);
if (err)
@@ -197,7 +208,7 @@ static struct netconsole_target *alloc_param_target(char *target_config)
if (err)
goto fail;
- nt->enabled = 1;
+ nt->enabled = true;
return nt;
@@ -258,6 +269,11 @@ static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
}
+static ssize_t show_extended(struct netconsole_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", nt->extended);
+}
+
static ssize_t show_dev_name(struct netconsole_target *nt, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
@@ -322,13 +338,18 @@ static ssize_t store_enabled(struct netconsole_target *nt,
return err;
if (enabled < 0 || enabled > 1)
return -EINVAL;
- if (enabled == nt->enabled) {
+ if ((bool)enabled == nt->enabled) {
pr_info("network logging has already %s\n",
nt->enabled ? "started" : "stopped");
return -EINVAL;
}
- if (enabled) { /* 1 */
+ if (enabled) { /* true */
+ if (nt->extended && !(netconsole_ext.flags & CON_ENABLED)) {
+ netconsole_ext.flags |= CON_ENABLED;
+ register_console(&netconsole_ext);
+ }
+
/*
* Skip netpoll_parse_options() -- all the attributes are
* already configured via configfs. Just print them out.
@@ -340,13 +361,13 @@ static ssize_t store_enabled(struct netconsole_target *nt,
return err;
pr_info("netconsole: network logging started\n");
- } else { /* 0 */
+ } else { /* false */
/* 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
+ * nt->np.dev == NULL and nt->enabled == true
*/
spin_lock_irqsave(&target_list_lock, flags);
- nt->enabled = 0;
+ nt->enabled = false;
spin_unlock_irqrestore(&target_list_lock, flags);
netpoll_cleanup(&nt->np);
}
@@ -356,6 +377,30 @@ static ssize_t store_enabled(struct netconsole_target *nt,
return strnlen(buf, count);
}
+static ssize_t store_extended(struct netconsole_target *nt,
+ const char *buf,
+ size_t count)
+{
+ int extended;
+ int err;
+
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ return -EINVAL;
+ }
+
+ err = kstrtoint(buf, 10, &extended);
+ if (err < 0)
+ return err;
+ if (extended < 0 || extended > 1)
+ return -EINVAL;
+
+ nt->extended = extended;
+
+ return strnlen(buf, count);
+}
+
static ssize_t store_dev_name(struct netconsole_target *nt,
const char *buf,
size_t count)
@@ -508,6 +553,7 @@ static struct netconsole_target_attr netconsole_target_##_name = \
__CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
NETCONSOLE_TARGET_ATTR_RW(enabled);
+NETCONSOLE_TARGET_ATTR_RW(extended);
NETCONSOLE_TARGET_ATTR_RW(dev_name);
NETCONSOLE_TARGET_ATTR_RW(local_port);
NETCONSOLE_TARGET_ATTR_RW(remote_port);
@@ -518,6 +564,7 @@ NETCONSOLE_TARGET_ATTR_RW(remote_mac);
static struct configfs_attribute *netconsole_target_attrs[] = {
&netconsole_target_enabled.attr,
+ &netconsole_target_extended.attr,
&netconsole_target_dev_name.attr,
&netconsole_target_local_port.attr,
&netconsole_target_remote_port.attr,
@@ -562,10 +609,10 @@ 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);
+ mutex_lock(&dynamic_netconsole_mutex);
if (na->store)
ret = na->store(nt, buf, count);
- mutex_unlock(&nt->mutex);
+ mutex_unlock(&dynamic_netconsole_mutex);
return ret;
}
@@ -594,7 +641,7 @@ static struct config_item *make_netconsole_target(struct config_group *group,
/*
* Allocate and initialize with defaults.
- * Target is disabled at creation (enabled == 0).
+ * Target is disabled at creation (!enabled).
*/
nt = kzalloc(sizeof(*nt), GFP_KERNEL);
if (!nt)
@@ -604,7 +651,6 @@ static struct config_item *make_netconsole_target(struct config_group *group,
strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
nt->np.local_port = 6665;
nt->np.remote_port = 6666;
- mutex_init(&nt->mutex);
eth_broadcast_addr(nt->np.remote_mac);
/* Initialize the config_item member */
@@ -695,7 +741,7 @@ restart:
spin_lock_irqsave(&target_list_lock, flags);
dev_put(nt->np.dev);
nt->np.dev = NULL;
- nt->enabled = 0;
+ nt->enabled = false;
stopped = true;
netconsole_target_put(nt);
goto restart;
@@ -729,6 +775,82 @@ static struct notifier_block netconsole_netdev_notifier = {
.notifier_call = netconsole_netdev_event,
};
+/**
+ * send_ext_msg_udp - send extended log message to target
+ * @nt: target to send message to
+ * @msg: extended log message to send
+ * @msg_len: length of message
+ *
+ * Transfer extended log @msg to @nt. If @msg is longer than
+ * MAX_PRINT_CHUNK, it'll be split and transmitted in multiple chunks with
+ * ncfrag header field added to identify them.
+ */
+static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
+ int msg_len)
+{
+ static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */
+ const char *header, *body;
+ int offset = 0;
+ int header_len, body_len;
+
+ if (msg_len <= MAX_PRINT_CHUNK) {
+ netpoll_send_udp(&nt->np, msg, msg_len);
+ return;
+ }
+
+ /* need to insert extra header fields, detect header and body */
+ header = msg;
+ body = memchr(msg, ';', msg_len);
+ if (WARN_ON_ONCE(!body))
+ return;
+
+ header_len = body - header;
+ body_len = msg_len - header_len - 1;
+ body++;
+
+ /*
+ * Transfer multiple chunks with the following extra header.
+ * "ncfrag=<byte-offset>/<total-bytes>"
+ */
+ memcpy(buf, header, header_len);
+
+ while (offset < body_len) {
+ int this_header = header_len;
+ int this_chunk;
+
+ this_header += scnprintf(buf + this_header,
+ sizeof(buf) - this_header,
+ ",ncfrag=%d/%d;", offset, body_len);
+
+ this_chunk = min(body_len - offset,
+ MAX_PRINT_CHUNK - this_header);
+ if (WARN_ON_ONCE(this_chunk <= 0))
+ return;
+
+ memcpy(buf + this_header, body + offset, this_chunk);
+
+ netpoll_send_udp(&nt->np, buf, this_header + this_chunk);
+
+ offset += this_chunk;
+ }
+}
+
+static void write_ext_msg(struct console *con, const char *msg,
+ unsigned int len)
+{
+ struct netconsole_target *nt;
+ unsigned long flags;
+
+ if ((oops_only && !oops_in_progress) || list_empty(&target_list))
+ return;
+
+ spin_lock_irqsave(&target_list_lock, flags);
+ list_for_each_entry(nt, &target_list, list)
+ if (nt->extended && nt->enabled && netif_running(nt->np.dev))
+ send_ext_msg_udp(nt, msg, len);
+ spin_unlock_irqrestore(&target_list_lock, flags);
+}
+
static void write_msg(struct console *con, const char *msg, unsigned int len)
{
int frag, left;
@@ -744,8 +866,7 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
spin_lock_irqsave(&target_list_lock, flags);
list_for_each_entry(nt, &target_list, list) {
- netconsole_target_get(nt);
- if (nt->enabled && netif_running(nt->np.dev)) {
+ if (!nt->extended && nt->enabled && 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
@@ -760,11 +881,16 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
left -= frag;
}
}
- netconsole_target_put(nt);
}
spin_unlock_irqrestore(&target_list_lock, flags);
}
+static struct console netconsole_ext = {
+ .name = "netcon_ext",
+ .flags = CON_EXTENDED, /* starts disabled, registered on first use */
+ .write = write_ext_msg,
+};
+
static struct console netconsole = {
.name = "netcon",
.flags = CON_ENABLED,
@@ -787,7 +913,11 @@ static int __init init_netconsole(void)
goto fail;
}
/* Dump existing printks when we register */
- netconsole.flags |= CON_PRINTBUFFER;
+ if (nt->extended)
+ netconsole_ext.flags |= CON_PRINTBUFFER |
+ CON_ENABLED;
+ else
+ netconsole.flags |= CON_PRINTBUFFER;
spin_lock_irqsave(&target_list_lock, flags);
list_add(&nt->list, &target_list);
@@ -803,6 +933,8 @@ static int __init init_netconsole(void)
if (err)
goto undonotifier;
+ if (netconsole_ext.flags & CON_ENABLED)
+ register_console(&netconsole_ext);
register_console(&netconsole);
pr_info("network logging started\n");
@@ -831,6 +963,7 @@ static void __exit cleanup_netconsole(void)
{
struct netconsole_target *nt, *tmp;
+ unregister_console(&netconsole_ext);
unregister_console(&netconsole);
dynamic_netconsole_exit();
unregister_netdevice_notifier(&netconsole_netdev_notifier);