commit 868ab8923a2ec977faafec97ecafac0c3159c1b2 Author: Florian Weimer Date: Thu Jun 13 18:56:30 2024 +0200 resolv: Track single-request fallback via _res._flags (bug 31476) This avoids changing _res.options, which inteferes with change detection as part of automatic reloading of /etc/resolv.conf. Reviewed-by: DJ Delorie diff -Nrup a/resolv/res_send.c b/resolv/res_send.c --- a/resolv/res_send.c 2025-02-19 21:54:08.104421209 -0500 +++ b/resolv/res_send.c 2025-02-19 21:54:51.202625194 -0500 @@ -1065,9 +1065,11 @@ send_dg(res_state statp, seconds /= statp->nscount; if (seconds <= 0) seconds = 1; - bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0; - bool single_request = (((statp->options & RES_SNGLKUP) != 0) - | single_request_reopen); + bool single_request_reopen = ((statp->options & RES_SNGLKUPREOP) + || (statp->_flags & RES_F_SNGLKUPREOP)); + bool single_request = ((statp->options & RES_SNGLKUP) + || (statp->_flags & RES_F_SNGLKUP) + || single_request_reopen); int save_gotsomewhere = *gotsomewhere; int retval; @@ -1124,14 +1126,14 @@ send_dg(res_state statp, have received the first answer. */ if (!single_request) { - statp->options |= RES_SNGLKUP; + statp->_flags |= RES_F_SNGLKUP; single_request = true; *gotsomewhere = save_gotsomewhere; goto retry; } else if (!single_request_reopen) { - statp->options |= RES_SNGLKUPREOP; + statp->_flags |= RES_F_SNGLKUPREOP; single_request_reopen = true; *gotsomewhere = save_gotsomewhere; __res_iclose (statp, false); diff -Nrup a/resolv/resolv-internal.h b/resolv/resolv-internal.h --- a/resolv/resolv-internal.h 2025-02-19 21:54:08.104421209 -0500 +++ b/resolv/resolv-internal.h 2025-02-19 21:56:25.771072777 -0500 @@ -26,7 +26,8 @@ #define RES_F_VC 0x00000001 /* Socket is TCP. */ #define RES_F_CONN 0x00000002 /* Socket is connected. */ #define RES_F_EDNS0ERR 0x00000004 /* EDNS0 caused errors. */ - +#define RES_F_SNGLKUP 0x00200000 /* Private version of RES_SNGLKUP. */ +#define RES_F_SNGLKUPREOP 0x00400000 /* Private version of RES_SNGLKUPREOP. */ /* Internal version of RES_USE_INET6 which does not trigger a deprecation warning. */