netconsole: append release to sysdata

Append the init_utsname()->release to sysdata buffer before sending the
message in case the feature is set.

Signed-off-by: Breno Leitao <[email protected]>
Rev

netconsole: append release to sysdata

Append the init_utsname()->release to sysdata buffer before sending the
message in case the feature is set.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: add 'sysdata' suffix to related functions

This commit appends a common "sysdata" suffix to functions responsible
for appending data to sysdata.

This change enhances code clarity and pre

netconsole: add 'sysdata' suffix to related functions

This commit appends a common "sysdata" suffix to functions responsible
for appending data to sysdata.

This change enhances code clarity and prevents naming conflicts with
other "append" functions, particularly in anticipation of the upcoming
inclusion of the `release` field in the next patch.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: implement configfs for release_enabled

Implement the configfs helpers to show and set release_enabled configfs
directories under userdata.

When enabled, set the feature bit in netconsol

netconsole: implement configfs for release_enabled

Implement the configfs helpers to show and set release_enabled configfs
directories under userdata.

When enabled, set the feature bit in netconsole_target->sysdata_fields.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: introduce 'release' as a new sysdata field

This commit adds a new feature to the sysdata structure, allowing the
kernel release/version to be appended as part of sysdata. Additionally,
i

netconsole: introduce 'release' as a new sysdata field

This commit adds a new feature to the sysdata structure, allowing the
kernel release/version to be appended as part of sysdata. Additionally,
it updates the logic to count this new field as a used entry when
enabled.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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net, treewide: define and use MAC_ADDR_STR_LEN

There are a few places in the tree which compute the length of the
string representation of a MAC address as 3 * ETH_ALEN - 1. Define a
constant for th

net, treewide: define and use MAC_ADDR_STR_LEN

There are a few places in the tree which compute the length of the
string representation of a MAC address as 3 * ETH_ALEN - 1. Define a
constant for this and use it where relevant. No functionality changes
are expected.

Signed-off-by: Uday Shankar <[email protected]>
Reviewed-by: Michal Swiatkowski <[email protected]>
Acked-by: Johannes Berg <[email protected]>
Reviewed-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: add task name to extra data fields

This is the core patch for this whole patchset. Add support for
including the current task's name in netconsole's extra data output.
This adds a new ap

netconsole: add task name to extra data fields

This is the core patch for this whole patchset. Add support for
including the current task's name in netconsole's extra data output.
This adds a new append_taskname() function that writes the task name
(from current->comm) into the target's extradata buffer, similar to how
CPU numbers are handled.

The task name is included when the SYSDATA_TASKNAME field is set,
appearing in the format "taskname=<name>" in the output. This additional
context can help with debugging by showing which task generated each
console message.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: add configfs controls for taskname sysdata feature

Add configfs interface to enable/disable the taskname sysdata feature.
This adds the following functionality:

The implementation follo

netconsole: add configfs controls for taskname sysdata feature

Add configfs interface to enable/disable the taskname sysdata feature.
This adds the following functionality:

The implementation follows the same pattern as the existing CPU number
feature, ensuring consistent behavior and error handling across sysdata
features.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: add taskname to extradata entry count

New SYSDATA_TASKNAME feature flag to track when taskname append is enabled.

Additional check in count_extradata_entries() to include taskname in
to

netconsole: add taskname to extradata entry count

New SYSDATA_TASKNAME feature flag to track when taskname append is enabled.

Additional check in count_extradata_entries() to include taskname in
total, counting it as an entry in extradata. This function is used to
check if we are not overflowing the number of extradata items.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: refactor CPU number formatting into separate function

Extract CPU number formatting logic from prepare_extradata() into a new
append_cpu_nr() function.

This refactoring improves code or

netconsole: refactor CPU number formatting into separate function

Extract CPU number formatting logic from prepare_extradata() into a new
append_cpu_nr() function.

This refactoring improves code organization by isolating CPU number
formatting into its own function while reducing the complexity of
prepare_extradata().

The change prepares the codebase for the upcoming taskname feature by
establishing a consistent pattern for handling sysdata features.

The CPU number formatting logic itself remains unchanged; only its
location has moved to improve maintainability.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: Make boolean comparison consistent

Convert the current state assignment to use explicit boolean conversion,
making the code more robust and easier to read. This change adds a
double-nega

netconsole: Make boolean comparison consistent

Convert the current state assignment to use explicit boolean conversion,
making the code more robust and easier to read. This change adds a
double-negation operator to ensure consistent boolean conversion as
suggested by Paolo[1].

This approach aligns with the existing pattern used in
sysdata_cpu_nr_enabled_show().

Link: https://lore.kernel.org/all/[email protected]/ [1]
Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: prefix CPU_NR sysdata feature with SYSDATA_

Rename the CPU_NR enum value to SYSDATA_CPU_NR to establish a consistent
naming convention for sysdata features. This change prepares for
upco

netconsole: prefix CPU_NR sysdata feature with SYSDATA_

Rename the CPU_NR enum value to SYSDATA_CPU_NR to establish a consistent
naming convention for sysdata features. This change prepares for
upcoming additions to the sysdata feature set by clearly grouping
related features under the SYSDATA prefix.

This change is purely cosmetic and does not modify any functionality.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netconsole: add support for sysdata and CPU population

Add infrastructure to automatically append kernel-generated data (sysdata)
to netconsole messages. As the first use case, implement CPU number

netconsole: add support for sysdata and CPU population

Add infrastructure to automatically append kernel-generated data (sysdata)
to netconsole messages. As the first use case, implement CPU number
population, which adds the CPU that sent the message.

This change introduces three distinct data types:
- extradata: The complete set of appended data (sysdata + userdata)
- userdata: User-provided key-value pairs from userspace
- sysdata: Kernel-populated data (e.g. cpu=XX)

The implementation adds a new configfs attribute 'cpu_nr' to control CPU
number population per target. When enabled, each message is tagged with
its originating CPU. The sysdata is dynamically updated at message time
and appended after any existing userdata.

The CPU number is formatted as "cpu=XX" and is added to the extradata
buffer, respecting the existing size limits.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netconsole: Include sysdata in extradata entry count

Modify count_extradata_entries() to include sysdata fields when
calculating the total number of extradata entries. This change ensures
that the s

netconsole: Include sysdata in extradata entry count

Modify count_extradata_entries() to include sysdata fields when
calculating the total number of extradata entries. This change ensures
that the sysdata feature, specifically the CPU number field, is
correctly counted against the MAX_EXTRADATA_ITEMS limit.

The modification adds a simple check for the CPU_NR flag in the
sysdata_fields, incrementing the entry count accordingly.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netconsole: Introduce configfs helpers for sysdata features

This patch introduces a bitfield to store sysdata features in the
netconsole_target struct. It also adds configfs helpers to enable
or dis

netconsole: Introduce configfs helpers for sysdata features

This patch introduces a bitfield to store sysdata features in the
netconsole_target struct. It also adds configfs helpers to enable
or disable the CPU_NR feature, which populates the CPU number in
sysdata.

The patch provides the necessary infrastructure to set or unset the
CPU_NR feature, but does not modify the message itself.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netconsole: Helper to count number of used entries

Add a helper function nr_extradata_entries() to count the number of used
extradata entries in a netconsole target. This refactors the duplicate
cod

netconsole: Helper to count number of used entries

Add a helper function nr_extradata_entries() to count the number of used
extradata entries in a netconsole target. This refactors the duplicate
code for counting entries into a single function, which will be reused
by upcoming CPU sysdata changes.

The helper uses list_count_nodes() to count the number of children in
the userdata group configfs hierarchy.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netconsole: Rename userdata to extradata

Rename "userdata" to "extradata" since this structure will hold both
user and system data in future patches. Keep "userdata" term only for
data that comes fr

netconsole: Rename userdata to extradata

Rename "userdata" to "extradata" since this structure will hold both
user and system data in future patches. Keep "userdata" term only for
data that comes from userspace (configfs), while "extradata" encompasses
both userdata and future kerneldata.

These are the rules of the design

1. extradata_complete will hold userdata and sysdata (coming)
2. sysdata will come after userdata_length
3. extradata_complete[userdata_length] string will be replaced at every
message
5. userdata is replaced when configfs changes (update_userdata())
6. sysdata is replaced at every message

Example:
extradata_complete = "userkey=uservalue cpu=42"
userdata_length = 17
sysdata_length = 7 (space (" ") is part of sysdata)

Since sysdata is still not available, you will see the following in the
send functions:

extradata_len = nt->userdata_length;

The upcoming patches will, which will add support for sysdata, will
change it to:

extradata_len = nt->userdata_length + sysdata_len;

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netconsole: consolidate send buffers into netconsole_target struct

Move the static buffers from send_msg_no_fragmentation() and
send_msg_fragmented() into the netconsole_target structure. This
simpl

netconsole: consolidate send buffers into netconsole_target struct

Move the static buffers from send_msg_no_fragmentation() and
send_msg_fragmented() into the netconsole_target structure. This
simplifies the code by:
- Eliminating redundant static buffers
- Centralizing buffer management in the target structure
- Reducing memory usage by 1KB (one buffer instead of two)

The buffer in netconsole_target is protected by target_list_lock,
maintaining the same synchronization semantics as the original code.

Suggested-by: Jakub Kicinski <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netconsole: Warn if MAX_USERDATA_ITEMS limit is exceeded

netconsole configfs helpers doesn't allow the creation of more than
MAX_USERDATA_ITEMS items.

Add a warning when netconsole userdata update

netconsole: Warn if MAX_USERDATA_ITEMS limit is exceeded

netconsole configfs helpers doesn't allow the creation of more than
MAX_USERDATA_ITEMS items.

Add a warning when netconsole userdata update function attempts sees
more than MAX_USERDATA_ITEMS entries.

Replace silent ignore mechanism with WARN_ON_ONCE() to highlight
potential misuse during development and debugging.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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netcons: Add udp send fail statistics to netconsole

Enhance observability of netconsole. Packet sends can fail.
Start tracking at least two failure possibilities: ENOMEM and
NET_XMIT_DROP for every

netcons: Add udp send fail statistics to netconsole

Enhance observability of netconsole. Packet sends can fail.
Start tracking at least two failure possibilities: ENOMEM and
NET_XMIT_DROP for every target. Stats are exposed via an additional
attribute in CONFIGFS.

The exposed statistics allows easier debugging of cases when netconsole
messages were not seen by receivers, eliminating the guesswork if the
sender thinks that messages in question were sent out.

Stats are not reset on enable/disable/change remote ip/etc, they
belong to the netcons target itself.

Reported-by: Breno Leitao <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Maksym Kutsevol <[email protected]>
Link: https://patch.msgid.link/20241202-netcons-add-udp-send-fail-statistics-to-netconsole-v5-2-70e82239f922@kutsevol.com
Signed-off-by: Jakub Kicinski <[email protected]>

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net: netconsole: split send_msg_fragmented

Refactor the send_msg_fragmented() function by extracting the logic for
sending the message body into a new function called
send_fragmented_body().

Now, s

net: netconsole: split send_msg_fragmented

Refactor the send_msg_fragmented() function by extracting the logic for
sending the message body into a new function called
send_fragmented_body().

Now, send_msg_fragmented() handles appending the release and header, and
then delegates the task of breaking up the body and sending the
fragments to send_fragmented_body().

This is the final flow now:

When send_ext_msg_udp() is called to send a message, it will:
- call send_msg_no_fragmentation() if no fragmentation is needed
or
- call send_msg_fragmented() if fragmentation is needed
* send_msg_fragmented() appends the header to the buffer, which is
be persisted until the function returns
* call send_fragmented_body() to iterate and populate the body of
the message. It will not touch the header, and it will only
replace the body, writing the msgbody and/or userdata.

Also add some comment to make the code easier to review.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: netconsole: do not pass userdata up to the tail

Do not pass userdata to send_msg_fragmented, since we can get it later.

This will be more useful in the next patch, where send_msg_fragmented()

net: netconsole: do not pass userdata up to the tail

Do not pass userdata to send_msg_fragmented, since we can get it later.

This will be more useful in the next patch, where send_msg_fragmented()
will be split even more, and userdata is only necessary in the last
function.

Suggested-by: Simon Horman <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: netconsole: extract release appending into separate function

Refactor the code by extracting the logic for appending the
release into the buffer into a separate function.

The goal is to reduce

net: netconsole: extract release appending into separate function

Refactor the code by extracting the logic for appending the
release into the buffer into a separate function.

The goal is to reduce the size of send_msg_fragmented() and improve
code readability.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: netconsole: track explicitly if msgbody was written to buffer

The current check to determine if the message body was fully sent is
difficult to follow. To improve clarity, introduce a variable

net: netconsole: track explicitly if msgbody was written to buffer

The current check to determine if the message body was fully sent is
difficult to follow. To improve clarity, introduce a variable that
explicitly tracks whether the message body (msgbody) has been completely
sent, indicating when it's time to begin sending userdata.

Additionally, add comments to make the code more understandable for
others who may work with it.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: netconsole: introduce variable to track body length

This new variable tracks the total length of the data to be sent,
encompassing both the message body (msgbody) and userdata, which is
collect

net: netconsole: introduce variable to track body length

This new variable tracks the total length of the data to be sent,
encompassing both the message body (msgbody) and userdata, which is
collectively called body.

By explicitly defining body_len, the code becomes clearer and easier to
reason about, simplifying offset calculations and improving overall
readability of the function.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: netconsole: rename body to msg_body

With the introduction of the userdata concept, the term body has become
ambiguous and less intuitive.

To improve clarity, body is renamed to msg_body, makin

net: netconsole: rename body to msg_body

With the introduction of the userdata concept, the term body has become
ambiguous and less intuitive.

To improve clarity, body is renamed to msg_body, making it clear that
the body is not the only content following the header.

In an upcoming patch, the term body_len will also be revised for further
clarity.

The current packet structure is as follows:

release, header, body, [msg_body + userdata]

Here, [msg_body + userdata] collectively forms what is currently
referred to as "body." This renaming helps to distinguish and better
understand each component of the packet.

Signed-off-by: Breno Leitao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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