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authorBreno Leitao <leitao@debian.org>2023-07-14 04:13:29 -0700
committerPaolo Abeni <pabeni@redhat.com>2023-07-18 11:04:59 +0200
commitc62c0a17f9b7398022f9eebe547878033264f81f (patch)
tree5a9d6e98dfc0f0839dd06e660265b47cc290be4b /drivers/net/netconsole.c
parenta7f6eb19e26dc81b1bc469689b9a4c2caceaf852 (diff)
downloadlwn-c62c0a17f9b7398022f9eebe547878033264f81f.tar.gz
lwn-c62c0a17f9b7398022f9eebe547878033264f81f.zip
netconsole: Append kernel version to message
Create a new netconsole runtime option that prepends the kernel version in the netconsole message. This is useful to map kernel messages to kernel version in a simple way, i.e., without checking somewhere which kernel version the host that sent the message is using. If this option is selected, then the "<release>," is prepended before the netconsole message. This is an example of a netconsole output, with release feature enabled: 6.4.0-01762-ga1ba2ffe946e;12,426,112883998,-;this is a test Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20230714111330.3069605-1-leitao@debian.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'drivers/net/netconsole.c')
-rw-r--r--drivers/net/netconsole.c81
1 files changed, 78 insertions, 3 deletions
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 4f4f79532c6c..31cbe02eda49 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -36,6 +36,7 @@
#include <linux/inet.h>
#include <linux/configfs.h>
#include <linux/etherdevice.h>
+#include <linux/utsname.h>
MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
MODULE_DESCRIPTION("Console driver for network interfaces");
@@ -84,6 +85,8 @@ static struct console netconsole_ext;
* Also, other parameters of a target may be modified at
* runtime only when it is disabled (enabled == 0).
* @extended: Denotes whether console is extended or not.
+ * @release: Denotes whether kernel release version should be prepended
+ * to the message. Depends on extended console.
* @np: The netpoll structure for this target.
* Contains the other userspace visible parameters:
* dev_name (read-write)
@@ -101,6 +104,7 @@ struct netconsole_target {
#endif
bool enabled;
bool extended;
+ bool release;
struct netpoll np;
};
@@ -188,6 +192,15 @@ static struct netconsole_target *alloc_param_target(char *target_config)
target_config++;
}
+ if (*target_config == 'r') {
+ if (!nt->extended) {
+ pr_err("Netconsole configuration error. Release feature requires extended log message");
+ goto fail;
+ }
+ nt->release = true;
+ target_config++;
+ }
+
/* Parse parameters and setup netpoll */
err = netpoll_parse_options(&nt->np, target_config);
if (err)
@@ -222,6 +235,7 @@ static void free_param_target(struct netconsole_target *nt)
* |
* <target>/
* | enabled
+ * | release
* | dev_name
* | local_port
* | remote_port
@@ -254,6 +268,11 @@ static ssize_t extended_show(struct config_item *item, char *buf)
return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->extended);
}
+static ssize_t release_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->release);
+}
+
static ssize_t dev_name_show(struct config_item *item, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n", to_target(item)->np.dev_name);
@@ -332,6 +351,11 @@ static ssize_t enabled_store(struct config_item *item,
}
if (enabled) { /* true */
+ if (nt->release && !nt->extended) {
+ pr_err("Not enabling netconsole. Release feature requires extended log message");
+ goto out_unlock;
+ }
+
if (nt->extended && !console_is_registered(&netconsole_ext))
register_console(&netconsole_ext);
@@ -366,6 +390,38 @@ out_unlock:
return err;
}
+static ssize_t release_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ int release;
+ int err;
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ err = kstrtoint(buf, 10, &release);
+ if (err < 0)
+ goto out_unlock;
+ if (release < 0 || release > 1) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ nt->release = release;
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return err;
+}
+
static ssize_t extended_store(struct config_item *item, const char *buf,
size_t count)
{
@@ -576,10 +632,12 @@ CONFIGFS_ATTR(, local_ip);
CONFIGFS_ATTR(, remote_ip);
CONFIGFS_ATTR_RO(, local_mac);
CONFIGFS_ATTR(, remote_mac);
+CONFIGFS_ATTR(, release);
static struct configfs_attribute *netconsole_target_attrs[] = {
&attr_enabled,
&attr_extended,
+ &attr_release,
&attr_dev_name,
&attr_local_port,
&attr_remote_port,
@@ -772,9 +830,23 @@ static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
const char *header, *body;
int offset = 0;
int header_len, body_len;
+ const char *msg_ready = msg;
+ const char *release;
+ int release_len = 0;
+
+ if (nt->release) {
+ release = init_utsname()->release;
+ release_len = strlen(release) + 1;
+ }
- if (msg_len <= MAX_PRINT_CHUNK) {
- netpoll_send_udp(&nt->np, msg, msg_len);
+ if (msg_len + release_len <= MAX_PRINT_CHUNK) {
+ /* No fragmentation needed */
+ if (nt->release) {
+ scnprintf(buf, MAX_PRINT_CHUNK, "%s,%s", release, msg);
+ msg_len += release_len;
+ msg_ready = buf;
+ }
+ netpoll_send_udp(&nt->np, msg_ready, msg_len);
return;
}
@@ -792,7 +864,10 @@ static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
* Transfer multiple chunks with the following extra header.
* "ncfrag=<byte-offset>/<total-bytes>"
*/
- memcpy(buf, header, header_len);
+ if (nt->release)
+ scnprintf(buf, MAX_PRINT_CHUNK, "%s,", release);
+ memcpy(buf + release_len, header, header_len);
+ header_len += release_len;
while (offset < body_len) {
int this_header = header_len;