Completely rework the autotools build system, issues have cropped up due to the complexity and could cause issues on even semi-modern Linux systems (Ubuntu 20.04 for example).
Changes include:
Remove all curl/xc/cares m4 helper files, they go overboard on detections of functions and datatypes. Go back to more plain autoconf macros as they've come a long way over the years.
Use known systems and heuristics to determine datatypes for functions like send() and recv(), rather than the error prone detection which required thousands of permutations and might still get it wrong.
Remove unneeded configure arguments like --enable-debug or --enable-optimize, its more common for people to simply pass their own CFLAGS on the command line.
Only require CARES_STATICLIB definition on Windows static builds, its not necessary ever for other systems, even when hiding non-public symbols.
Remove some function and definition detections that were never used in c-ares
The test framework is now embedded into the toplevel configure system, there was no need to chain build the test system as it is never built externally to c-ares.
As a side-effect of the changes, a configure run completes in about 25% of the original time.
This has been tested on various Linux distributions (of varying age), FreeBSD, MacOS, Windows (via MSYS2 with Mingw), and Solaris10/11 (by @dfandrich), AIX 7.3 (by @dfandrich). It is not unlikely that this may have broken more esoteric or legacy systems, and we'll likely need to be ready to accept bug reports and patches, but it has removed over 10k lines of build system code. It is very likely any issues that crop up will add far fewer lines of code to fix such systems.
Fixes Bug: #670
Fix By: Brad House (@bradh352)
* get rid of clashes with curl namespace
* remove warnings due to deprecated functionality
* reorder some macro calls to get rid of warnings due to being called in the wrong order
Fix By: Brad House (@bradh352)
GoogleTest should be unbundled. Google changed their guidance a few years back and modern versions of google test cannot build the bundling code file.
This PR also updates to use C++14 as is required by modern GoogleTest versions.
Fixes Bug: #506
Fix By: Brad House (@bradh352)
Some environments may send router advertisements on a link setting their link-local (fe80::/10) address as a valid DNS server to the remote system. This will cause a DNS entry to be created like `fe80::1%iface`, since all link-local network interfaces are technically part of the same /10 subnet, it must be told what interface to send packets through explicitly if there are multiple physical interfaces.
This PR adds support for the %iface modifier when setting DNS servers via `/etc/resolv.conf` as well as via `ares_set_servers_csv()`.
For MacOS and iOS it is assumed that libresolve will set the `sin6_scope_id` and should be supported, but my test systems don't seem to read the Router Advertisement for RDNSS link-local. Specifying the link-local dns server on MacOS via adig has been tested and confirmed working.
For Windows, this is similar to MacOS in that the system doesn't seem to honor the RDNSS RA, but specifying manually has been tested to work.
At this point, Android support does not exist.
Fixes Bug #462
Supersedes PR #463
Fix By: Brad House (@bradh352) and Serhii Purik (@sergvpurik)
HOSTS FILE PROCESSING OVERVIEW
==============================
The hosts file on the system contains static entries to be processed locally
rather than querying the nameserver. Each row is an IP address followed by
a list of space delimited hostnames that match the ip address. This is used
for both forward and reverse lookups.
We are caching the entire parsed hosts file for performance reasons. Some
files may be quite sizable and as per Issue #458 can approach 1/2MB in size,
and the parse overhead on a rapid succession of queries can be quite large.
The entries are stored in forwards and backwards hashtables so we can get
O(1) performance on lookup. The file is cached until the file modification
timestamp changes (or 60s if there is no implemented stat() capability).
The hosts file processing is quite unique. It has to merge all related hosts
and ips into a single entry due to file formatting requirements. For
instance take the below:
```
127.0.0.1 localhost.localdomain localhost
::1 localhost.localdomain localhost
192.168.1.1 host.example.com host
192.168.1.5 host.example.com host
2620🔢:1 host.example.com host6.example.com host6 host
```
This will yield 2 entries.
1) ips: `127.0.0.1,::1`
hosts: `localhost.localdomain,localhost`
2) ips: `192.168.1.1,192.168.1.5,2620🔢:1`
hosts: `host.example.com,host,host6.example.com,host6`
It could be argued that if searching for `192.168.1.1` that the `host6`
hostnames should not be returned, but this implementation will return them
since they are related (both ips have the fqdn of host.example.com). It is
unlikely this will matter in the real world.
Fix By: Brad House (@bradh352)
c-ares was missing a couple of common compiler warnings during building that are widely recognized as a best practice. This PR makes no code changes, only build system changes to increase warning levels.
This PR does cause some new warnings to be emitted, a follow-up PR will address those.
Fix By: Brad House (@bradh352)
All files have their licence and copyright information clearly
identifiable. If not in the file header, they are set separately in
.reuse/dep5.
All used license texts are provided in LICENSES/
* segment random number generation into own file
* abstract random code to make it more modular so we can have multiple backends
* rand: add support for arc4random_buf() and also direct CARES_RANDOM_FILE reading
* autotools: fix detection of arc4random_buf
* rework initial rc4 seed for PRNG as last fallback
* rc4: more proper implementation, simplified for clarity
* clarifications
Options `-we ###` and `-wd ###` should not include a whitespace. They are also deprecated and `-diag-error` and `-diag-disable` are their replacements.
Intel compiler 2021.6 is not able to be used in configure without the proposed patch.
Fix By: Stephen Sachs (@stephenmsachs)
ax_code_coverage.m4 dropped the @CODE_COVERAGE_RULES@ macro, so we need to switch to the latest recommendation from the m4 file. This requires updates to Makefile.am.
Fix By: Felix Yan (@felixonmars)
The rc4 function iterates over a buffer of size buffer_len who's maximum
value is INT_MAX with a counter of type short that is not guaranteed to
have maximum size INT_MAX.
In circumstances where short is narrower than int and where buffer_len
is larger than the maximum value of a short, it may be possible to loop
infinitely as counter will overflow and never be greater than or equal
to buffer_len.
The solution is to make the comparison be between types of equal width.
This commit defines counter as an int.
Fix By: Fionn Fitzmaurice (@fionn)
Brad House
Daniel Stenberg
Ben Noordhuis
Tim Wojtulewicz
Jay Freeman (saurik)
Stephen Sachs
Felix Yan
Fionn Fitzmaurice