Issue #20208 has been updated by kjtsanaktsidis (KJ Tsanaktsidis). I discussed this a bit with @ioquatix, we've decided to revert the change to make AI_ADDRCONFIG be used in DNS lookups by default. The interaction with services on localhost is just too surprising. ---------------------------------------- Bug #20208: Net::HTTP errors with Errno::EAFNOSUPPORT when setting local_host with Addrinfo https://bugs.ruby-lang.org/issues/20208#change-106545 * Author: jprokop (Jarek Prokop) * Status: Assigned * Priority: Normal * Assignee: kjtsanaktsidis (KJ Tsanaktsidis) * ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-linux] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- A bug was found when dealing with Ruby tests downstream. One of our builders has a specific networking configuration, resulting in Ruby incorrectly binding a socket, resulting in exception Errno::EAFNOSUPPORT, despite localhost being IPv6 capable. It is reproducible with Ruby 3.3, and reasonably current master (git hash a846d391d38b34fcc4f90adef967c166c923bd56). Reproduction environment: The networking configuration has to be in a specific state. The regular interface (such as eth0) has to have ipv6 disabled while localhost is IPv6 enabled. I have tracked the problem to a commit adding AI_ADDRCONFIG flag: https://github.com/ruby/ruby/commit/d2ba8ea54a4089959afdeecdd963e3c4ff391748... If I revert the commit or just simply set 2 ifdefs that are present in the diff with `HAVE_CONST_AI_ADDRCONFIG` to 0, the problem no longer occurs. I have used vagrant with fedora/39-cloud-base box with the above mentioned git hash. However, I'd note that I reproduced it also on RHEL 8 and RHEL 9. The VM has the following interfaces: ~~~ $ ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host noprefixroute valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 52:54:00:e3:aa:c1 brd ff:ff:ff:ff:ff:ff altname enp0s5 altname ens5 inet 192.168.122.209/24 brd 192.168.122.255 scope global dynamic noprefixroute eth0 valid_lft 2099sec preferred_lft 2099sec inet6 fe80::f5fe:e8a4:8f83:4a8f/64 scope link tentative noprefixroute valid_lft forever preferred_lft forever ~~~ Disable IPv6 of eth0 and leave only lo with IPv6: ~~~ $ sudo sysctl "net.ipv6.conf.eth0.disable_ipv6=1" ~~~ Confirm the result: ~~~ $ ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host noprefixroute valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 52:54:00:e3:aa:c1 brd ff:ff:ff:ff:ff:ff altname enp0s5 altname ens5 inet 192.168.122.209/24 brd 192.168.122.255 scope global dynamic noprefixroute eth0 valid_lft 3587sec preferred_lft 3587sec ~~~ inet6 is no longer present on eth0, but still present in lo. Then we can copy what TestNetHTTPLocalBind is doing in setup, as that is one of the failing tests and use it for a reproducer: ~~~ $ ruby -rnet/http -e 'http = Net::HTTP.new("localhost", 8080); http.local_host = Addrinfo.tcp("localhost", 8080).ip_address; p http.get("/")' /usr/share/ruby/net/http.rb:1603:in `initialize': Failed to open TCP connection to localhost:8080 (Address family not supported by protocol - bind(2) for "::1" port ) (Errno::EAFNOSUPPORT) from /usr/share/ruby/net/http.rb:1603:in `open' from /usr/share/ruby/net/http.rb:1603:in `block in connect' from /usr/share/ruby/timeout.rb:186:in `block in timeout' from /usr/share/ruby/timeout.rb:193:in `timeout' from /usr/share/ruby/net/http.rb:1601:in `connect' from /usr/share/ruby/net/http.rb:1580:in `do_start' from /usr/share/ruby/net/http.rb:1569:in `start' from /usr/share/ruby/net/http.rb:2297:in `request' from /usr/share/ruby/net/http.rb:1917:in `get' from -e:1:in `<main>' /usr/share/ruby/net/http.rb:1603:in `initialize': Address family not supported by protocol - bind(2) for "::1" port (Errno::EAFNOSUPPORT) from /usr/share/ruby/net/http.rb:1603:in `open' from /usr/share/ruby/net/http.rb:1603:in `block in connect' from /usr/share/ruby/timeout.rb:186:in `block in timeout' from /usr/share/ruby/timeout.rb:193:in `timeout' from /usr/share/ruby/net/http.rb:1601:in `connect' from /usr/share/ruby/net/http.rb:1580:in `do_start' from /usr/share/ruby/net/http.rb:1569:in `start' from /usr/share/ruby/net/http.rb:2297:in `request' from /usr/share/ruby/net/http.rb:1917:in `get' from -e:1:in `<main>' ~~~ The script: ~~~ http = Net::HTTP.new("localhost", 8080) http.local_host = Addrinfo.tcp("localhost", 8080).ip_address p http.get("/") ~~~ Without setting the `http.local_host` attribute using Addrinfo, the reproducer does not fail with EAFNOSUPPORT. Whether `port` is specified or `nil` does not make a difference. Whether there is a server listening on 8080 or not does not make a difference, the script fails with the errno regardless. I have collected `strace` that points to a possible cause: ~~~ $ strace ruby -rnet/http -e 'http = Net::HTTP.new("localhost", 8080); http.local_host = Addrinfo.tcp("localhost", 8080).ip_address; p http.get("/")' 2>&1 | grep AF_INET socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_TCP) = 5 bind(5, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = -1 EAFNOSUPPORT (Address family not supported by protocol) ~~~ A socket is created with AF_INET and later is bound with AF_INET6, that is not correct behavior as far as I can tell. Full strace is attached. Observed failures in Ruby test suite related to this issue: ~~~ 109) Error: TestNetHTTPLocalBind#test_bind_to_local_port: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:37337 (Address family not supported by protocol - bind(2) for "::1" port 45395) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1282:in `test_bind_to_local_port' 110) Error: TestNetHTTPLocalBind#test_bind_to_local_host: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:46329 (Address family not supported by protocol - bind(2) for "::1" port ) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1267:in `test_bind_to_local_host' 111) Error: TestNetHTTPForceEncoding#test_response_body_encoding_false: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:41749 (Address family not supported by protocol - bind(2) for "::1" port ) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1308:in `fe_request' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1312:in `test_response_body_encoding_false' 112) Error: TestNetHTTPForceEncoding#test_response_body_encoding_string_without_content_type: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:42775 (Address family not supported by protocol - bind(2) for "::1" port ) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1308:in `fe_request' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1330:in `test_response_body_encoding_string_without_content_type' 113) Error: TestNetHTTPForceEncoding#test_response_body_encoding_true_with_content_type: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:36895 (Address family not supported by protocol - bind(2) for "::1" port ) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1308:in `fe_request' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1324:in `test_response_body_encoding_true_with_content_type' 114) Error: TestNetHTTPForceEncoding#test_response_body_encoding_encoding_without_content_type: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:37115 (Address family not supported by protocol - bind(2) for "::1" port ) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1308:in `fe_request' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1336:in `test_response_body_encoding_encoding_without_content_type' 115) Error: TestNetHTTPForceEncoding#test_response_body_encoding_true_without_content_type: Errno::EAFNOSUPPORT: Failed to open TCP connection to localhost:37799 (Address family not supported by protocol - bind(2) for "::1" port ) /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `initialize' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `open' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1603:in `block in connect' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:186:in `block in timeout' /builddir/build/BUILD/ruby-3.3.0/lib/timeout.rb:193:in `timeout' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1601:in `connect' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1580:in `do_start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1569:in `start' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:2297:in `request' /builddir/build/BUILD/ruby-3.3.0/lib/net/http.rb:1917:in `get' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1308:in `fe_request' /builddir/build/BUILD/ruby-3.3.0/test/net/http/test_http.rb:1318:in `test_response_body_encoding_true_without_content_type' ~~~ Related failures from specs: ~~~ 1) An exception occurred during: before :each TCPSocket#local_address using IPv6 using an implicit hostname the returned Addrinfo uses the correct IP address ERROR Errno::ECONNREFUSED: Connection refused - connect(2) for nil port 37121 /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/local_address_spec.rb:59:in `initialize' /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/local_address_spec.rb:59:in `new' /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/local_address_spec.rb:59:in `block (4 levels) in <top (required)>' /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/local_address_spec.rb:4:in `<top (required)>' 2) An exception occurred during: before :each TCPSocket#remote_address using IPv6 using an implicit hostname the returned Addrinfo uses the correct IP address ERROR Errno::ECONNREFUSED: Connection refused - connect(2) for nil port 39823 /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/remote_address_spec.rb:58:in `initialize' /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/remote_address_spec.rb:58:in `new' /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/remote_address_spec.rb:58:in `block (4 levels) in <top (required)>' /builddir/build/BUILD/ruby-3.3.0/spec/ruby/library/socket/tcpsocket/remote_address_spec.rb:4:in `<top (required)>' ~~~ ---Files-------------------------------- strace_log.txt (304 KB) -- https://bugs.ruby-lang.org/