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| author | Simon Kelley <simon@thekelleys.org.uk> | 2023-03-07 22:46:44 +0000 |
|---|---|---|
| committer | Simon Kelley <simon@thekelleys.org.uk> | 2023-03-08 12:47:45 +0000 |
| commit | ef8e930e4295265b8f46898a8e166f17d7f8ddc8 (patch) | |
| tree | b04a943e8514e10a425d8bf3a78cca920a18f8db | |
| parent | eb92fb32b746f2104b0f370b5b295bb8dd4bd5e5 (diff) | |
| download | dnsmasq-ef8e930e4295265b8f46898a8e166f17d7f8ddc8.tar.gz | |
Generalise cached NXDOMAIN replies.
We can cache an NXDOMAIN reply to a query for any RRTYPE
and reply from a cached NXDOMAIN to any RRTYPE.
| -rw-r--r-- | src/rfc1035.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/src/rfc1035.c b/src/rfc1035.c index 1693253..3d82ad9 100644 --- a/src/rfc1035.c +++ b/src/rfc1035.c @@ -894,9 +894,8 @@ int extract_addresses(struct dns_header *header, size_t qlen, char *name, time_t { flags &= ~(F_IPV4 | F_IPV6 | F_SRV); - /* Can store NXDOMAIN reply to CNAME or ANY query. */ - if (qtype == T_CNAME || qtype == T_ANY) - insert = 1; + /* Can store NXDOMAIN reply for any qtype. */ + insert = 1; } log_query(F_UPSTREAM | F_FORWARD | F_NEG | flags | (secure ? F_DNSSECOK : 0), name, NULL, NULL, 0); @@ -2081,7 +2080,22 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen, } if (!ans) - return 0; /* failed to answer a question */ + { + /* We may know that the domain doesn't exist for any RRtype. */ + if ((crecp = cache_find_by_name(NULL, name, now, F_NXDOMAIN))) + { + ans = nxdomain = 1; + auth = 0; + + if (!(crecp->flags & F_DNSSECOK)) + sec_data = 0; + + if (!dryrun) + log_query(F_NXDOMAIN | F_NEG, name, NULL, NULL, 0); + } + else + return 0; /* failed to answer a question */ + } } if (dryrun) |