Files
coredns/plugin/bufsize
Syed Azeez 7b38eb8625 plugin: fix gosec G115 integer overflow warnings (#7799)
Fix integer overflow conversion warnings (G115) by adding appropriate
suppressions where values are provably bounded.

Fixes: https://github.com/coredns/coredns/issues/7793

Changes:
- Updated 56 G115 annotations to use consistent // #nosec G115 format
- Added 2 //nolint:gosec suppressions for conditional expressions
- Removed G115 exclusion from golangci.yml (now explicitly handled per-line)

Suppressions justify why each conversion is safe (e.g., port numbers
are bounded 1-65535, DNS TTL limits, pool lengths, etc.)

Signed-off-by: Azeez Syed <syedazeez337@gmail.com>
2026-01-01 10:20:29 +02:00
..
2023-07-10 07:49:52 -07:00
2023-07-10 07:49:52 -07:00

bufsize

Name

bufsize - limits EDNS0 buffer size to prevent IP fragmentation.

Description

bufsize limits a requester's UDP payload size to within a maximum value. If a request with an OPT RR has a bufsize greater than the limit, the bufsize of the request will be reduced. Otherwise the request is unaffected. It prevents IP fragmentation, mitigating certain DNS vulnerabilities. It cannot increase UDP size requested by the client, it can be reduced only. This will only affect queries that have an OPT RR (EDNS(0)).

Syntax

bufsize [SIZE]

[SIZE] is an int value for setting the buffer size. The default value is 1232, and the value must be within 512 - 4096. Only one argument is acceptable, and it covers both IPv4 and IPv6.

Examples

Enable limiting the buffer size of outgoing query to the resolver (172.31.0.10):

. {
    bufsize 1100
    forward . 172.31.0.10
    log
}

Enable limiting the buffer size as an authoritative nameserver:

. {
    bufsize 1220
    file db.example.org
    log
}

Considerations

  • Setting 1232 bytes to bufsize may avoid fragmentation on the majority of networks in use today, but it depends on the MTU of the physical network links.