diff options
Diffstat (limited to 'drivers/net/netconsole.c')
| -rw-r--r-- | drivers/net/netconsole.c | 169 |
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); |