Gitweb:
https://git.exim.org/exim.git/commitdiff/b574c5baeb94e3a176c63982f507a5b48bf3917b
Commit: b574c5baeb94e3a176c63982f507a5b48bf3917b
Parent: b4a15239139c285af7009b4fcc23e1933b19173b
Author: Jeremy Harris <jgh146exb@???>
AuthorDate: Sun Oct 27 18:00:05 2019 +0000
Committer: Jeremy Harris <jgh146exb@???>
CommitDate: Sun Oct 27 18:08:43 2019 +0000
Refactor the res_search() fail hack
---
src/src/dns.c | 65 ++++++++++++++++++++++++++++----------------------------
test/stderr/0002 | 1 +
test/stderr/0044 | 2 ++
test/stderr/0094 | 2 ++
test/stderr/0183 | 7 ++++++
test/stderr/0361 | 3 +++
test/stderr/0381 | 2 ++
test/stderr/0419 | 2 ++
test/stderr/0545 | 2 ++
test/stderr/1006 | 4 ++++
test/stderr/2201 | 1 +
test/stderr/4802 | 2 ++
test/stderr/4803 | 2 ++
13 files changed, 62 insertions(+), 33 deletions(-)
diff --git a/src/src/dns.c b/src/src/dns.c
index 8d9ec47..28bc595 100644
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -681,17 +681,6 @@ return rc;
-/* Return the TTL suitable for an NXDOMAIN result, which is given
-in the SOA. We hope that one was returned in the lookup, and do not
-bother doing a separate lookup; if not found return a forever TTL.
-*/
-
-time_t
-dns_expire_from_soa(dns_answer * dnsa)
-{
-const HEADER * h = (const HEADER *)dnsa->answer;
-dns_scan dnss;
-
/* This is really gross. The successful return value from res_search() is
the packet length, which is stored in dnsa->answerlen. If we get a
negative DNS reply then res_search() returns -1, which causes the bounds
@@ -703,12 +692,38 @@ re-implement res_search() and res_query() so that they don't muddle their
success and packet length return values.) For added safety we only reset
the packet length if the packet header looks plausible. */
-if ( h->qr == 1 && h->opcode == QUERY && h->tc == 0
+static void
+fake_dnsa_len_for_fail(dns_answer * dnsa)
+{
+const HEADER * h = (const HEADER *)dnsa->answer;
+
+if ( h->qr == 1 /* a response */
+ && h->opcode == QUERY
+ && h->tc == 0 /* nmessage not truncated */
&& (h->rcode == NOERROR || h->rcode == NXDOMAIN)
- && (ntohs(h->qdcount) == 1 || f.running_in_test_harness)
- && ntohs(h->ancount) == 0
- && ntohs(h->nscount) >= 1)
- dnsa->answerlen = sizeof(dnsa->answer);
+ && ( ntohs(h->qdcount) == 1 /* one question record */
+ || f.running_in_test_harness)
+ && ntohs(h->ancount) == 0 /* no answer records */
+ && ntohs(h->nscount) >= 1) /* authority records */
+ {
+ DEBUG(D_dns) debug_printf("faking res_search() response length as %d\n",
+ (int)sizeof(dnsa->answer));
+ dnsa->answerlen = sizeof(dnsa->answer);
+ }
+}
+
+
+/* Return the TTL suitable for an NXDOMAIN result, which is given
+in the SOA. We hope that one was returned in the lookup, and do not
+bother doing a separate lookup; if not found return a forever TTL.
+*/
+
+time_t
+dns_expire_from_soa(dns_answer * dnsa)
+{
+dns_scan dnss;
+
+fake_dnsa_len_for_fail(dnsa);
for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY);
rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
@@ -1185,23 +1200,7 @@ switch (type)
if (rc == DNS_NOMATCH)
{
- /* This is really gross. The successful return value from res_search() is
- the packet length, which is stored in dnsa->answerlen. If we get a
- negative DNS reply then res_search() returns -1, which causes the bounds
- checks for name decompression to fail when it is treated as a packet
- length, which in turn causes the authority search to fail. The correct
- packet length has been lost inside libresolv, so we have to guess a
- replacement value. (The only way to fix this properly would be to
- re-implement res_search() and res_query() so that they don't muddle their
- success and packet length return values.) For added safety we only reset
- the packet length if the packet header looks plausible. */
-
- const HEADER * h = (const HEADER *)dnsa->answer;
- if (h->qr == 1 && h->opcode == QUERY && h->tc == 0
- && (h->rcode == NOERROR || h->rcode == NXDOMAIN)
- && ntohs(h->qdcount) == 1 && ntohs(h->ancount) == 0
- && ntohs(h->nscount) >= 1)
- dnsa->answerlen = sizeof(dnsa->answer);
+ fake_dnsa_len_for_fail(dnsa);
for (rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY);
rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
diff --git a/test/stderr/0002 b/test/stderr/0002
index 8f85e71..3fbb40d 100644
--- a/test/stderr/0002
+++ b/test/stderr/0002
@@ -298,6 +298,7 @@ looking up host name for V4NET.0.0.1
DNS lookup of 1.0.0.V4NET.in-addr.arpa (PTR) using fakens
DNS lookup of 1.0.0.V4NET.in-addr.arpa (PTR) succeeded
IP address lookup yielded "ten-1.test.ex"
+faking res_search() response length as 65535
DNS lookup of ten-1.test.ex (A) using fakens
DNS lookup of ten-1.test.ex (A) succeeded
ten-1.test.ex V4NET.0.0.1 mx=-1 sort=xx
diff --git a/test/stderr/0044 b/test/stderr/0044
index d2891b8..1dcde9f 100644
--- a/test/stderr/0044
+++ b/test/stderr/0044
@@ -240,7 +240,9 @@ new DNS lookup for 99.99.99.V4NET.rbl.test.ex
DNS lookup of 99.99.99.V4NET.rbl.test.ex (A) using fakens
DNS lookup of 99.99.99.V4NET.rbl.test.ex (A) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
writing neg-cache entry for 99.99.99.V4NET.rbl.test.ex-A-xxxx, ttl 3000
+faking res_search() response length as 65535
dnslists: wrote cache entry, ttl=3000
DNS lookup for 99.99.99.V4NET.rbl.test.ex failed
=> that means V4NET.99.99.99 is not listed at rbl.test.ex
diff --git a/test/stderr/0094 b/test/stderr/0094
index 26cf916..d464d0a 100644
--- a/test/stderr/0094
+++ b/test/stderr/0094
@@ -83,12 +83,14 @@ DNS lookup of 90.99.99.V4NET.in-addr.arpa (PTR) using fakens
DNS lookup of 90.99.99.V4NET.in-addr.arpa (PTR) succeeded
IP address lookup yielded "oneback.test.ex"
alias "host1.masq.test.ex"
+faking res_search() response length as 65535
DNS lookup of oneback.test.ex (A) using fakens
DNS lookup of oneback.test.ex (A) succeeded
oneback.test.ex V4NET.99.99.90 mx=-1 sort=xx
checking addresses for oneback.test.ex
Forward DNS security status: unverified
V4NET.99.99.90 OK
+faking res_search() response length as 65535
DNS lookup of host1.masq.test.ex (A) using fakens
DNS lookup of host1.masq.test.ex (A) succeeded
host1.masq.test.ex V4NET.90.90.90 mx=-1 sort=xx
diff --git a/test/stderr/0183 b/test/stderr/0183
index 8b3450b..46d536a 100644
--- a/test/stderr/0183
+++ b/test/stderr/0183
@@ -92,6 +92,7 @@ ten-1.test.ex in "*"? yes (matched "*")
DNS lookup of ten-1.test.ex (MX) using fakens
DNS lookup of ten-1.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for ten-1.test.ex-MX-xxxx, ttl 3000
ten-1.test.ex (MX resp) DNSSEC
DNS lookup of ten-1.test.ex (A) using fakens
@@ -300,6 +301,7 @@ ten-1.test.ex in "*"? yes (matched "*")
DNS lookup of ten-1.test.ex (MX) using fakens
DNS lookup of ten-1.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for ten-1.test.ex-MX-xxxx, ttl 3000
ten-1.test.ex (MX resp) DNSSEC
DNS lookup of ten-1.test.ex (A) using fakens
@@ -450,6 +452,7 @@ nonexist.test.ex in "*"? yes (matched "*")
DNS lookup of nonexist.test.ex (MX) using fakens
DNS lookup of nonexist.test.ex (MX) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
writing neg-cache entry for nonexist.test.ex-MX-xxxx, ttl 3000
lookuphost router declined for userx@???
"more" is false: skipping remaining routers
@@ -509,6 +512,7 @@ ten-1.test.ex in "*"? yes (matched "*")
DNS lookup of ten-1.test.ex (MX) using fakens
DNS lookup of ten-1.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for ten-1.test.ex-MX-xxxx, ttl 3000
ten-1.test.ex (MX resp) DNSSEC
DNS lookup of ten-1.test.ex (A) using fakens
@@ -553,6 +557,7 @@ nonexist.test.ex in "*"? yes (matched "*")
DNS lookup of nonexist.test.ex (A) using fakens
DNS lookup of nonexist.test.ex (A) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
writing neg-cache entry for nonexist.test.ex-A-xxxx, ttl 3000
useryz router: defer for usery@???
message: lookup of host "nonexist.test.ex" failed in useryz router
@@ -724,6 +729,7 @@ nonexist.example.com in "*"? yes (matched "*")
DNS lookup of nonexist.example.com (MX) using fakens
DNS lookup of nonexist.example.com (MX) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
writing neg-cache entry for nonexist.example.com-MX-xxxx, ttl 2
lookuphost router declined for userx@???
"more" is false: skipping remaining routers
@@ -767,6 +773,7 @@ DNS lookup of nonexist.example.com-MX: cached value DNS_NOMATCH past valid time
DNS lookup of nonexist.example.com (MX) using fakens
DNS lookup of nonexist.example.com (MX) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
update neg-cache entry for nonexist.example.com-MX-xxxx, ttl 2
delay router declined for userd@???
"more" is false: skipping remaining routers
diff --git a/test/stderr/0361 b/test/stderr/0361
index 0e5ef67..a8634a3 100644
--- a/test/stderr/0361
+++ b/test/stderr/0361
@@ -100,14 +100,17 @@ recurse.test.ex in "*"? yes (matched "*")
DNS lookup of recurse.test.ex (MX) using fakens
DNS lookup of recurse.test.ex (MX) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
writing neg-cache entry for recurse.test.ex-MX-xxxx, ttl 3000
r1 router widened recurse.test.ex to recurse.test.ex.test.ex
recurse.test.ex.test.ex in "*"? yes (matched "*")
DNS lookup of recurse.test.ex.test.ex (MX) using fakens
DNS lookup of recurse.test.ex.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for recurse.test.ex.test.ex-MX-xxxx, ttl 3000
recurse.test.ex.test.ex (MX resp) DNSSEC
+faking res_search() response length as 65535
DNS lookup of recurse.test.ex.test.ex (A) using fakens
DNS lookup of recurse.test.ex.test.ex (A) succeeded
fully qualified name = recurse.test.ex.test.ex
diff --git a/test/stderr/0381 b/test/stderr/0381
index 42b52d0..9cab097 100644
--- a/test/stderr/0381
+++ b/test/stderr/0381
@@ -41,12 +41,14 @@ DNS lookup of 97.99.99.V4NET.in-addr.arpa (PTR) using fakens
DNS lookup of 97.99.99.V4NET.in-addr.arpa (PTR) succeeded
IP address lookup yielded "x.gov.uk.test.ex"
alias "x.co.uk.test.ex"
+faking res_search() response length as 65535
DNS lookup of x.gov.uk.test.ex (A) using fakens
DNS lookup of x.gov.uk.test.ex (A) succeeded
x.gov.uk.test.ex V4NET.99.99.97 mx=-1 sort=xx
checking addresses for x.gov.uk.test.ex
Forward DNS security status: unverified
V4NET.99.99.97 OK
+faking res_search() response length as 65535
DNS lookup of x.co.uk.test.ex (A) using fakens
DNS lookup of x.co.uk.test.ex (A) succeeded
x.co.uk.test.ex V4NET.99.99.97 mx=-1 sort=xx
diff --git a/test/stderr/0419 b/test/stderr/0419
index 39c7970..0671390 100644
--- a/test/stderr/0419
+++ b/test/stderr/0419
@@ -25,8 +25,10 @@ dnslookup router called for k@???
mxt13.test.ex in "*"? yes (matched "*")
DNS lookup of mxt13.test.ex (MX) using fakens
DNS lookup of mxt13.test.ex (MX) succeeded
+faking res_search() response length as 65535
DNS lookup of other1.test.ex (A) using fakens
DNS lookup of other1.test.ex (A) succeeded
+faking res_search() response length as 65535
DNS lookup of other2.test.ex (A) using fakens
DNS lookup of other2.test.ex (A) succeeded
other1.test.ex in "!mxt13.test.ex : !other1.test.ex : *.test.ex"? no (matched "!other1.test.ex")
diff --git a/test/stderr/0545 b/test/stderr/0545
index 93cdfc6..a17553a 100644
--- a/test/stderr/0545
+++ b/test/stderr/0545
@@ -25,6 +25,7 @@ CNAME found: change to eximtesthost.test.ex
DNS lookup of eximtesthost.test.ex (MX) using fakens
DNS lookup of eximtesthost.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for eximtesthost.test.ex-MX-xxxx, ttl 3000
alias-eximtesthost (MX resp) DNSSEC
DNS lookup of alias-eximtesthost (A) using fakens
@@ -99,6 +100,7 @@ CNAME found: change to eximtesthost.test.ex
DNS lookup of eximtesthost.test.ex (MX) using fakens
DNS lookup of eximtesthost.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for eximtesthost.test.ex-MX-xxxx, ttl 3000
alias-eximtesthost.test.ex (MX resp) DNSSEC
DNS lookup of alias-eximtesthost.test.ex (A) using fakens
diff --git a/test/stderr/1006 b/test/stderr/1006
index d569343..c5dec18 100644
--- a/test/stderr/1006
+++ b/test/stderr/1006
@@ -13,11 +13,13 @@ DNS lookup of 46.test.ex (A) succeeded
DNS lookup of v6.test.ex (MX) using fakens
DNS lookup of v6.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for v6.test.ex-MX-xxxx, ttl 3000
DNS lookup of v6.test.ex (AAAA) succeeded
DNS lookup of v6.test.ex (A) using fakens
DNS lookup of v6.test.ex (A) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for v6.test.ex-A-xxxx, ttl 3000
>>>>>>>>>>>>>>>> Exim pid=pppp (main) terminating with rc=0 >>>>>>>>>>>>>>>>
Exim version x.yz ....
@@ -33,10 +35,12 @@ DNS lookup of 46.test.ex (A) succeeded
DNS lookup of v6.test.ex (MX) using fakens
DNS lookup of v6.test.ex (MX) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for v6.test.ex-MX-xxxx, ttl 3000
DNS lookup of v6.test.ex (A) using fakens
DNS lookup of v6.test.ex (A) gave NO_DATA
returning DNS_NODATA
+faking res_search() response length as 65535
writing neg-cache entry for v6.test.ex-A-xxxx, ttl 3000
>>>>>>>>>>>>>>>> Exim pid=pppp (main) terminating with rc=2 >>>>>>>>>>>>>>>>
diff --git a/test/stderr/2201 b/test/stderr/2201
index 23ac937..0518369 100644
--- a/test/stderr/2201
+++ b/test/stderr/2201
@@ -99,6 +99,7 @@ dnsdb key: unknown
DNS lookup of unknown (TXT) using fakens
DNS lookup of unknown (TXT) gave HOST_NOT_FOUND
returning DNS_NOMATCH
+faking res_search() response length as 65535
writing neg-cache entry for unknown-TXT-xxxx, ttl 3000
lookup failed
unknown in "dnsdb;unknown"? no (end of list)
diff --git a/test/stderr/4802 b/test/stderr/4802
index 9575f88..a2510cc 100644
--- a/test/stderr/4802
+++ b/test/stderr/4802
@@ -4,6 +4,7 @@ admin user
dropping to exim gid; retaining priv uid
DNS lookup of mx-sec-a-aa.test.ex (MX) using fakens
DNS lookup of mx-sec-a-aa.test.ex (MX) succeeded
+faking res_search() response length as 65535
DNS lookup of a-aa.test.ex (A) using fakens
DNS lookup of a-aa.test.ex (A) succeeded
DNS lookup of a-aa.test.ex (A/AAAA) requested AD, but got AA
@@ -15,6 +16,7 @@ dropping to exim gid; retaining priv uid
DNS lookup of mx-aa-a-sec.test.ex (MX) using fakens
DNS lookup of mx-aa-a-sec.test.ex (MX) succeeded
DNS lookup of mx-aa-a-sec.test.ex (MX) requested AD, but got AA
+faking res_search() response length as 65535
DNS lookup of a-sec.test.ex (A) using fakens
DNS lookup of a-sec.test.ex (A) succeeded
>>>>>>>>>>>>>>>> Exim pid=pppp (main) terminating with rc=0 >>>>>>>>>>>>>>>>
diff --git a/test/stderr/4803 b/test/stderr/4803
index a7aa7bf..e86035a 100644
--- a/test/stderr/4803
+++ b/test/stderr/4803
@@ -4,6 +4,7 @@ admin user
dropping to exim gid; retaining priv uid
DNS lookup of mx-sec-a-aa.test.ex (MX) using fakens
DNS lookup of mx-sec-a-aa.test.ex (MX) succeeded
+faking res_search() response length as 65535
DNS lookup of a-aa.test.ex (A) using fakens
DNS lookup of a-aa.test.ex (A) succeeded
DNS faked the AD bit (got AA and matched with dns_trust_aa (test.ex in *))
@@ -19,6 +20,7 @@ DNS lookup of mx-aa-a-sec.test.ex (MX) succeeded
DNS faked the AD bit (got AA and matched with dns_trust_aa (test.ex in *))
DNS faked the AD bit (got AA and matched with dns_trust_aa (test.ex in *))
DNS faked the AD bit (got AA and matched with dns_trust_aa (test.ex in *))
+faking res_search() response length as 65535
DNS lookup of a-sec.test.ex (A) using fakens
DNS lookup of a-sec.test.ex (A) succeeded
>>>>>>>>>>>>>>>> Exim pid=pppp (main) terminating with rc=0 >>>>>>>>>>>>>>>>
