Linux kernel source tree
811b8f534f
In case of tc offload, when user space queries the kernel for tc action
statistics, tc will query the offloaded statistics from device drivers.
Among other statistics, drivers are expected to pass the number of
packets that hit the action since the last query as a 64-bit number.
Unfortunately, tc treats the number of packets as a 32-bit number,
leading to truncation and incorrect statistics when the number of
packets since the last query exceeds 0xffffffff:
$ tc -s filter show dev swp2 ingress
filter protocol all pref 1 flower chain 0
filter protocol all pref 1 flower chain 0 handle 0x1
skip_sw
in_hw in_hw_count 1
action order 1: mirred (Egress Redirect to device swp1) stolen
index 1 ref 1 bind 1 installed 58 sec used 0 sec
Action statistics:
Sent 1133877034176 bytes 536959475 pkt (dropped 0, overlimits 0 requeues 0)
[...]
According to the above, 2111-byte packets were redirected which is
impossible as only 64-byte packets were transmitted and the MTU was
1500.
Fix by treating packets as a 64-bit number:
$ tc -s filter show dev swp2 ingress
filter protocol all pref 1 flower chain 0
filter protocol all pref 1 flower chain 0 handle 0x1
skip_sw
in_hw in_hw_count 1
action order 1: mirred (Egress Redirect to device swp1) stolen
index 1 ref 1 bind 1 installed 61 sec used 0 sec
Action statistics:
Sent 1370624380864 bytes 21416005951 pkt (dropped 0, overlimits 0 requeues 0)
[...]
Which shows that only 64-byte packets were redirected (1370624380864 /
21416005951 = 64).
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.