When compiling c-ares with a build system that defines UNICODE,
bad versions of WinAPI functions are used causing failures or even
crashes. When windows.h is included in MBCS mode (like in the default
build system), the ..A versions are the same as using the one without
any suffix.
When `ares_cancel()` was invoked, `ares_gethostbyaddr()`
queries would fail with `ENOTFOUND` instead of `ECANCELLED`.
It seems appropriate to treat `ares_cancel()` like `ares_destroy()`,
but I would appreciate review of the correctness of this change.
Ref: https://github.com/nodejs/node/issues/14814Closes#138
qsort is not stable, in order to make it stable we need to record
the original index and add it as a secondary sort value when the
metrics are equal to prevent using DNS servers that may not work
at all as reported by some users.
9478908a49 introduced a length check
for records parsed by `ares_parse_naptr_reply()`. However, that
function is designed to parse replies which also contain non-NAPTR
records; for A records, the `rr_len > 7` check will fail as there
are only 4 bytes of payload.
In particular, parsing ANY replies for NAPTR records was broken
by that patch.
Fix that by moving the check into the case in which it is already
known that the record is a NAPTR record.
The TESTS target runs fuzzcheck.sh so make sure it is included
in the distributed tarball.
(The test itself will be pointless when run on a distribution, because
the fuzzing corpus directories are not shipped, but at least this
means that `make -C test test` should work.)
ares_process.c uses htonl, which needs <arpa/inet.h> included.
ares_getnameinfo.c uses a dynamically selected format string for
sprintf, which -Wformat-literal doesn't like. Usually one would use
inttypes.h and a format string "%" PRIu32, but C99 is too new for some
supported platforms.
This change solves issue #53.
Support for suffix search lists was already built in for Linux. The search list could be set via set_search. With this change the suffix search list from Windows is read from the registry and then set into the ares configuration via set_search. There are two sources for the search list:
The global DNS suffix search list.
The primary and connection specific DNS suffixes if the global is not available.
Contributed by @ChristianAmmer
Socklen_t should not be used in code, instead ares_socklen_t should be used.
Convert ssize_t to ares_ssize_t for portability since the public API now exposes this.
Original Patch From Brad Spencer:
https://c-ares.haxx.se/mail/c-ares-archive-2016-04/0000.shtml
My modifications include:
* Dynamically find GetBestRoute2 since it is a Windows Vista+ symbol, and will fall back to prior behavior when not available.
* Prefer get_DNS_AdaptersAddresses as the modifications should alleviate the concerns which caused us to prefer get_DNS_NetworkParams
* Update AppVeyor to use MinGW-w64 instead of the legacy MinGW
* Fix compile error in test suite for Windows.
Original message from patch below:
From: Brad Spencer <bspencer@blackberry.com>
Date: Fri, 29 Apr 2016 14:26:23 -0300
On Windows, the c-ares DNS resolver tries first to get a full list of
DNS server addresses by enumerating the system's IPv4/v6 interfaces and
then getting the per-interface DNS server lists from those interfaces
and joining them together. The OS, at least in the way the c-ares
prefers to query them (which also may be the only or best way in some
environments), does not provide a unified list of DNS servers ordered
according to "current network conditions". Currently, c-ares will then
try to use them in whatever order the nested enumeration produces, which
may result in DNS requests being sent to servers on one interface
(hosting the current default route, for example) that are only intended
to be used via another interface (intended to be used when the first
interface is not available, for example). This, in turn, can lead to
spurious failures and timeouts simply because of the server address
order that resulted because of the enumeration process.
This patch makes the (safe?) assumption that there is no other better
rule to chose which interface's DNS server list should be prioritized.
After all, a DNS lookup isn't something "per network"; applications
don't look up "these DNS names on this interface and those DNS names on
that interface". There is a single resource pool of DNS servers and the
application should presume that any server will give it the "right"
answer. However, even if all DNS servers are assumed to give equally
useful responses, it is reasonable to expect that some DNS servers will
not accept requests on all interfaces. This patch avoids the problem by
sorting the DNS server addresses using the Windows IPv4/v6 routing tables.
For example, a request to DNS server C on interface 2 that is actually
sent over interface 1 (which may happen to have the default route) may
be rejected by or not delivered to DNS server C. So, better to use DNS
servers A and B associated with interface 1, at least as a first try.
By using the metric of the route to the DNS server itself as a proxy for
priority of the DNS server in the list, this patch is able to adapt
dynamically to changes in the interface list, the DNS server lists per
interface, which interfaces are active, the routing table, and so on,
while always picking a good "best" DNS server first.
In cases where any DNS server on any interface will do, this patch still
seems useful because it will prioritize a lower-metric route's (and thus
interface's) servers.
The added api requires both some typedefs not previously imported
into the test build + the test code did not fully deal with
socket differences on windows.
Gergely Nagy
Brad House
David Drysdale
Anna Henningsen
David Hotham
Daniel Stenberg
Christian Ammer
noiz
Dionna Glaze
Gregor Jasny
Thomas Köckerbauer
Michael Osei
Sergii Pylypenko
Calle Wilund