Can you please post a small, self-contained program that reproduces the segfault?

I understand that it would be very desirable to have a small self-contained program reproducing it, but I am struggling a bit to provide this, as the issue occurs in the interaction with the OS and the DNS. I am currently unsure on how to wrap this into a simple reproducer. My test program looks something like this, with the DNS having an incorrect entry for "incorrectdnsentry.test.net" mapping to "dnsentry.test.net/" (the slash is not legal here): This set-up will produce a segfault on a Yocto-based Linux distribution. #include <iostream> #include int main(int argc, char* argv[]) { try { boost::asio::io_service io_service; boost::asio::ip::tcp::resolver resolver(io_service); boost::asio::ip::tcp::resolver::query query("incorrectdnsentry.test.net", "80"); boost::asio::ip::tcp::resolver::iterator iter = resolver.resolve(query); std::cout << "Host name was resolved to: " << iter->endpoint() << std::endl; } catch (const std::exception&) { std::cout << "Host name could not be resolved" << std::endl; } } What can be easily demonstrated though, is, that the translate_addrinfo_error function converts EAI_SYSTEM with errno=0 (which is triggered by the above set-up) into a Boost error code that shows success. So this program will output "Success". int main(int argc, char* argv[]) { auto ec = boost::asio::detail::socket_ops::translate_addrinfo_error(EAI_SYSTEM); std::cout << "Error message: " << ec.message() << std::endl; } Kind regards, Nils

On Tue, 24 Aug 2021 at 16:36, Niall Douglas via Boost-users wrote:

On 24/08/2021 13:57, Nils Frielinghaus via Boost-users wrote:

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What can be easily demonstrated though, is, that the translate_addrinfo_error function converts EAI_SYSTEM with errno=0 (which is triggered by the above set-up) into a Boost error code that shows success. So this program will output "Success".

This is a long standing design quirk of error_code which we have fixed in proposed status_code, which is hoped to supersede error_code in a future C++ standard.

I think you are talking about a different problem. The issue here is that https://pubs.opengroup.org/onlinepubs/9699919799/functions/getaddrinfo.html says "[EAI_SYSTEM] A system error occurred; the error code can be found in errno." and apparently there is a implementation not honouring this contract. This is happening way before there is any error_code.

On Tue, 24 Aug 2021 at 17:25, Niall Douglas via Boost-users wrote:

In proposed status_code we supply a getaddrinfo_code, so getaddrinfo codes get their own status code domain. EAI_SYSTEM compares equal to errc::resource_unavailable_try_again:

Not sure how I feel about that. I also have just noticed that while POSIX says "[EAI_SYSTEM] A system error occurred; the error code can be found in errno.", which IMHO clearly says errno must be != 0, https://man7.org/linux/man-pages/man3/getaddrinfo.3.html says "EAI_SYSTEM Other system error, check errno for details.". I guess the later could accept errno == 0, meaning "no details".

On Tue, 24 Aug 2021 at 16:36, Niall Douglas via Boost-users wrote:

...

On 24/08/2021 13:57, Nils Frielinghaus via Boost-users wrote:

...

What can be easily demonstrated though, is, that the translate_addrinfo_error function converts EAI_SYSTEM with errno=0 (which is triggered by the above set-up) into a Boost error code that shows success. So this program will output "Success".

This is a long standing design quirk of error_code which we have fixed in proposed status_code, which is hoped to supersede error_code in a future C++ standard.

I think you are talking about a different problem. The issue here is that https://pubs.opengroup.org/onlinepubs/9699919799/functions/getaddrinfo.html says "[EAI_SYSTEM] A system error occurred; the error code can be found in errno." and apparently there is a implementation not honouring this contract. This is happening way before there is any error_code.

Earlier in the cited document https://pubs.opengroup.org/onlinepubs/9699919799/functions/getaddrinfo.html it reads "A zero return value for getaddrinfo() indicates successful completion; a non-zero return value indicates failure." This suggests to me that it is not correct to consider the return value EAI_SYSTEM with errno = 0 as a successful return value and that it would be better to handle this as a system error with unidentified cause.

...

This suggests to me that it is not correct to consider the return value EAI_SYSTEM with errno = 0 as a successful return value and that it would be better to handle this as a system error with unidentified cause.

Yes, treating it as a success would be wrong. The question is whether it should be treated as: - A valid error - A post-condition violation in getaddrinfo

Who would be willing or entitled to do this determination?