diff mbox series

[net-next] net: netconsole: Add continuation line prefix to userdata messages

Message ID 20240228172948.221910-1-thepacketgeek@gmail.com
State New
Headers
Series [net-next] net: netconsole: Add continuation line prefix to userdata messages |

Commit Message

Matthew Wood Feb. 28, 2024, 5:29 p.m. UTC 
  Add a space (' ') prefix to every userdata line to match docs for
dev-kmsg. To account for this extra character in each userdata entry,
reduce userdata entry names (directory name) from 54 characters to 53.

According to the dev-kmsg docs, a space is used for subsequent lines to
mark them as continuation lines.

> A line starting with ' ', is a continuation line, adding
> key/value pairs to the log message, which provide the machine
> readable context of the message, for reliable processing in
> userspace.

Testing for this patch::

 cd /sys/kernel/config/netconsole && mkdir cmdline0
 cd cmdline0
 mkdir userdata/test && echo "hello" > userdata/test/value
 mkdir userdata/test2 && echo "hello2" > userdata/test2/value
 echo "message" > /dev/kmsg

Outputs::

 6.8.0-rc5-virtme,12,493,231373579,-;message
  test=hello
  test2=hello2

And I confirmed all testing works as expected from the original patchset

Fixes: df03f830d099 ("net: netconsole: cache userdata formatted string in netconsole_target")
Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
---
 Documentation/networking/netconsole.rst | 6 +++---
 drivers/net/netconsole.c                | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

Comments

Florian Fainelli Feb. 28, 2024, 5:32 p.m. UTC | #1 
On 2/28/24 09:29, Matthew Wood wrote:
> Add a space (' ') prefix to every userdata line to match docs for
> dev-kmsg. To account for this extra character in each userdata entry,
> reduce userdata entry names (directory name) from 54 characters to 53.
> 
> According to the dev-kmsg docs, a space is used for subsequent lines to
> mark them as continuation lines.
> 
>> A line starting with ' ', is a continuation line, adding
>> key/value pairs to the log message, which provide the machine
>> readable context of the message, for reliable processing in
>> userspace.
> 
> Testing for this patch::
> 
>   cd /sys/kernel/config/netconsole && mkdir cmdline0
>   cd cmdline0
>   mkdir userdata/test && echo "hello" > userdata/test/value
>   mkdir userdata/test2 && echo "hello2" > userdata/test2/value
>   echo "message" > /dev/kmsg
> 
> Outputs::
> 
>   6.8.0-rc5-virtme,12,493,231373579,-;message
>    test=hello
>    test2=hello2
> 
> And I confirmed all testing works as expected from the original patchset
> 
> Fixes: df03f830d099 ("net: netconsole: cache userdata formatted string in netconsole_target")
> Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
> ---
>   Documentation/networking/netconsole.rst | 6 +++---
>   drivers/net/netconsole.c                | 4 ++--
>   2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst
> index b28c525e5d1e..c2dec12f6060 100644
> --- a/Documentation/networking/netconsole.rst
> +++ b/Documentation/networking/netconsole.rst
> @@ -197,8 +197,8 @@ Messages will now include this additional user data::
>   Sends::
>   
>    12,607,22085407756,-;This is a message
> - foo=bar
> - qux=baz
> +  foo=bar
> +  qux=baz
>   
>   Preview the userdata that will be appended with::
>   
> @@ -218,7 +218,7 @@ The `qux` key is omitted since it has no value::
>   
>    echo "This is a message" > /dev/kmsg
>    12,607,22085407756,-;This is a message
> - foo=bar
> +  foo=bar
>   
>   Delete `userdata` entries with `rmdir`::
>   
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index 0de108a1c0c8..ffd3e19406b5 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -43,7 +43,7 @@ MODULE_DESCRIPTION("Console driver for network interfaces");
>   MODULE_LICENSE("GPL");
>   
>   #define MAX_PARAM_LENGTH	256
> -#define MAX_USERDATA_NAME_LENGTH	54
> +#define MAX_USERDATA_NAME_LENGTH	53 /* 256 - 200 - 3 (for ' =\n' chars)*/

Could we take this opportunity to define MAX_USERDATA_NAME_LENGTH based 
upon MAX_PARAM_LENGTH - MAX_USERDATA_VALUE_LENGTH - 3 then?

>   #define MAX_USERDATA_VALUE_LENGTH	200
>   #define MAX_USERDATA_ENTRY_LENGTH	256
>   #define MAX_USERDATA_ITEMS		16
> @@ -671,7 +671,7 @@ static void update_userdata(struct netconsole_target *nt)
>   		 * checked to not exceed MAX items with child_count above
>   		 */
>   		complete_idx += scnprintf(&nt->userdata_complete[complete_idx],
> -					  MAX_USERDATA_ENTRY_LENGTH, "%s=%s\n",
> +					  MAX_USERDATA_ENTRY_LENGTH, " %s=%s\n",
>   					  item->ci_name, udm_item->value);
>   	}
>   	nt->userdata_length = strnlen(nt->userdata_complete,
Matthew Wood Feb. 28, 2024, 7:51 p.m. UTC | #2 
On Wed, Feb 28, 2024 at 9:32 AM Florian Fainelli <f.fainelli@gmail.com> wrote:
>
> On 2/28/24 09:29, Matthew Wood wrote:
> > Add a space (' ') prefix to every userdata line to match docs for
> > dev-kmsg. To account for this extra character in each userdata entry,
> > reduce userdata entry names (directory name) from 54 characters to 53.
> >
> > According to the dev-kmsg docs, a space is used for subsequent lines to
> > mark them as continuation lines.
> >
> >> A line starting with ' ', is a continuation line, adding
> >> key/value pairs to the log message, which provide the machine
> >> readable context of the message, for reliable processing in
> >> userspace.
> >
> > Testing for this patch::
> >
> >   cd /sys/kernel/config/netconsole && mkdir cmdline0
> >   cd cmdline0
> >   mkdir userdata/test && echo "hello" > userdata/test/value
> >   mkdir userdata/test2 && echo "hello2" > userdata/test2/value
> >   echo "message" > /dev/kmsg
> >
> > Outputs::
> >
> >   6.8.0-rc5-virtme,12,493,231373579,-;message
> >    test=hello
> >    test2=hello2
> >
> > And I confirmed all testing works as expected from the original patchset
> >
> > Fixes: df03f830d099 ("net: netconsole: cache userdata formatted string in netconsole_target")
> > Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
> > ---
> >   Documentation/networking/netconsole.rst | 6 +++---
> >   drivers/net/netconsole.c                | 4 ++--
> >   2 files changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst
> > index b28c525e5d1e..c2dec12f6060 100644
> > --- a/Documentation/networking/netconsole.rst
> > +++ b/Documentation/networking/netconsole.rst
> > @@ -197,8 +197,8 @@ Messages will now include this additional user data::
> >   Sends::
> >
> >    12,607,22085407756,-;This is a message
> > - foo=bar
> > - qux=baz
> > +  foo=bar
> > +  qux=baz
> >
> >   Preview the userdata that will be appended with::
> >
> > @@ -218,7 +218,7 @@ The `qux` key is omitted since it has no value::
> >
> >    echo "This is a message" > /dev/kmsg
> >    12,607,22085407756,-;This is a message
> > - foo=bar
> > +  foo=bar
> >
> >   Delete `userdata` entries with `rmdir`::
> >
> > diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> > index 0de108a1c0c8..ffd3e19406b5 100644
> > --- a/drivers/net/netconsole.c
> > +++ b/drivers/net/netconsole.c
> > @@ -43,7 +43,7 @@ MODULE_DESCRIPTION("Console driver for network interfaces");
> >   MODULE_LICENSE("GPL");
> >
> >   #define MAX_PARAM_LENGTH    256
> > -#define MAX_USERDATA_NAME_LENGTH     54
> > +#define MAX_USERDATA_NAME_LENGTH     53 /* 256 - 200 - 3 (for ' =\n' chars)*/
>
> Could we take this opportunity to define MAX_USERDATA_NAME_LENGTH based
> upon MAX_PARAM_LENGTH - MAX_USERDATA_VALUE_LENGTH - 3 then?
>
> >   #define MAX_USERDATA_VALUE_LENGTH   200
> >   #define MAX_USERDATA_ENTRY_LENGTH   256
> >   #define MAX_USERDATA_ITEMS          16
> > @@ -671,7 +671,7 @@ static void update_userdata(struct netconsole_target *nt)
> >                * checked to not exceed MAX items with child_count above
> >                */
> >               complete_idx += scnprintf(&nt->userdata_complete[complete_idx],
> > -                                       MAX_USERDATA_ENTRY_LENGTH, "%s=%s\n",
> > +                                       MAX_USERDATA_ENTRY_LENGTH, " %s=%s\n",
> >                                         item->ci_name, udm_item->value);
> >       }
> >       nt->userdata_length = strnlen(nt->userdata_complete,
>
> --
> Florian
>

Yes, great suggestion. I'll send an update with this change tomorrow. thank you!
diff mbox series

Patch

diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst
index b28c525e5d1e..c2dec12f6060 100644
--- a/Documentation/networking/netconsole.rst
+++ b/Documentation/networking/netconsole.rst
@@ -197,8 +197,8 @@  Messages will now include this additional user data::
 Sends::
 
  12,607,22085407756,-;This is a message
- foo=bar
- qux=baz
+  foo=bar
+  qux=baz
 
 Preview the userdata that will be appended with::
 
@@ -218,7 +218,7 @@  The `qux` key is omitted since it has no value::
 
  echo "This is a message" > /dev/kmsg
  12,607,22085407756,-;This is a message
- foo=bar
+  foo=bar
 
 Delete `userdata` entries with `rmdir`::
 
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 0de108a1c0c8..ffd3e19406b5 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -43,7 +43,7 @@  MODULE_DESCRIPTION("Console driver for network interfaces");
 MODULE_LICENSE("GPL");
 
 #define MAX_PARAM_LENGTH	256
-#define MAX_USERDATA_NAME_LENGTH	54
+#define MAX_USERDATA_NAME_LENGTH	53 /* 256 - 200 - 3 (for ' =\n' chars)*/
 #define MAX_USERDATA_VALUE_LENGTH	200
 #define MAX_USERDATA_ENTRY_LENGTH	256
 #define MAX_USERDATA_ITEMS		16
@@ -671,7 +671,7 @@  static void update_userdata(struct netconsole_target *nt)
 		 * checked to not exceed MAX items with child_count above
 		 */
 		complete_idx += scnprintf(&nt->userdata_complete[complete_idx],
-					  MAX_USERDATA_ENTRY_LENGTH, "%s=%s\n",
+					  MAX_USERDATA_ENTRY_LENGTH, " %s=%s\n",
 					  item->ci_name, udm_item->value);
 	}
 	nt->userdata_length = strnlen(nt->userdata_complete,