New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add ERCodeRule #6147

merged 5 commits into from Jan 9, 2018


None yet
2 participants

zeha commented Jan 5, 2018

Short description

Add ERCodeRule to match on EDNS Extended RCodes.

Separate rule to avoid performance cost for non-EDNS packets. Unclear if this is a good idea for correctness.


I have:

  • read the document
  • compiled and tested this code
  • included documentation (including possible behaviour changes)
  • documented the code
  • added or modified regression test(s)
  • added or modified unit test(s)

@zeha zeha force-pushed the zeha:dnsdist-ercode branch from bab1fdb to d83feb6 Jan 5, 2018

@zeha zeha requested a review from rgacogne Jan 5, 2018


Nice work, just a few minor nits!

bool matches(const DNSQuestion* dq) const override
// avoid parsing EDNS OPT RR when not needed.
if (d_rcode != dq->dh->rcode) {

This comment has been minimized.


rgacogne Jan 8, 2018


Given that dq->dh->rcode is unsigned, perhaps d_rcode should be too? Same for d_extrcode since edns0.extRCode is an uint8_t.

char * optStart = NULL;
size_t optLen = 0;
bool last = false;
int res = locateEDNSOptRR((char*)dq->dh, dq->len, &optStart, &optLen, &last);

This comment has been minimized.


rgacogne Jan 8, 2018


const_cast<char*>(reinterpret_cast<const char*>(dq->dh)) ? I don't think we'll manage to get rid of the existing C-style casts, but it would be nice to add new ones as few as possible :)

EDNS0Record edns0;
static_assert(sizeof(EDNS0Record) == sizeof(uint32_t), "sizeof(EDNS0Record) must match sizeof(uint32_t) AKA RR TTL size");
memcpy(&edns0, optStart + 5, sizeof edns0);

This comment has been minimized.


rgacogne Jan 8, 2018


Adding a comment explaining where does the 5 comes from might be nice for later review.


This comment has been minimized.


zeha commented Jan 8, 2018

Nits addressed

@rgacogne rgacogne merged commit 1a26cc5 into PowerDNS:master Jan 9, 2018

1 check passed

continuous-integration/travis-ci/pr The Travis CI build passed

@zeha zeha deleted the zeha:dnsdist-ercode branch Jan 29, 2018

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment