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From: "fweimer at redhat dot com" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sourceware.org Subject: [Bug network/31476] New: Automatic activation of single-request options break resolv.conf reloading Date: Tue, 12 Mar 2024 06:43:31 +0000 [thread overview] Message-ID: <bug-31476-131@http.sourceware.org/bugzilla/> (raw) https://sourceware.org/bugzilla/show_bug.cgi?id=31476 Bug ID: 31476 Summary: Automatic activation of single-request options break resolv.conf reloading Product: glibc Version: unspecified Status: NEW Severity: normal Priority: P2 Component: network Assignee: unassigned at sourceware dot org Reporter: fweimer at redhat dot com Target Milestone: --- Flags: security- Initial report from John Levon: Issue with stale resolv.conf state <https://inbox.sourceware.org/libc-alpha/Ze7KCkIzR5PuErba@movementarian.org/> John traced the lack of reloading to a change in _res.options: “ I don't understand the first part of the comment, but indeed, ->resp doesn't match. In particular: 62 return ctx->resp->options == ctx->conf->options and ctx->resp (aka _resp) has 0x47002c1 whereas ctx->conf has 0x41002c1. I'm not sure but I suspect the additional RES_SNGLKUP|RES_SNGLKUPREOP may be due to this code: 1000 /* There are quite a few broken name servers out 1001 there which don't handle two outstanding 1002 requests from the same source. There are also 1003 broken firewall settings. If we time out after 1004 having received one answer switch to the mode 1005 where we send the second request only once we 1006 have received the first answer. */ 1007 if (!single_request) 1008 { 1009 statp->options |= RES_SNGLKUP; 1010 single_request = true; 1011 *gotsomewhere = save_gotsomewhere; 1012 goto retry; 1013 } 1014 else if (!single_request_reopen) 1015 { 1016 statp->options |= RES_SNGLKUPREOP; 1017 single_request_reopen = true; 1018 *gotsomewhere = save_gotsomewhere; 1019 __res_iclose (statp, false); 1020 goto retry_reopen; 1021 } I'm guessing these got set when the VPN dropped routing to the old nameservers, but before the next getaddrinfo() came in, thus leading to the match failing. ” -- You are receiving this mail because: You are on the CC list for the bug.
next reply other threads:[~2024-03-12 6:43 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-12 6:43 fweimer at redhat dot com [this message] 2024-03-12 6:45 ` [Bug network/31476] " fweimer at redhat dot com 2024-03-12 9:32 ` levon at movementarian dot org
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