From 462a1f6197fa3de63e0eca2835b1d5b0bc6a3bbb Mon Sep 17 00:00:00 2001 From: Christos Longros Date: Sun, 15 Mar 2026 16:17:04 +0100 Subject: [PATCH] resolver.5: document six previously undocumented options Document the edns0, inet6, insecure1, insecure2, no-check-names, and rotate options which are parsed by res_init(3) but were not described in the resolver(5) man page. MFC after: 1 week Signed-off-by: Christos Longros Reviewed by: des Differential Revision: https://reviews.freebsd.org/D55864 --- share/man/man5/resolver.5 | 40 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) diff --git a/share/man/man5/resolver.5 b/share/man/man5/resolver.5 index 9f8c0d689a0..4dd3f8c93a9 100644 --- a/share/man/man5/resolver.5 +++ b/share/man/man5/resolver.5 @@ -25,7 +25,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd November 23, 2022 +.Dd March 15, 2026 .Dt RESOLVER 5 .Os .Sh NAME @@ -170,6 +170,38 @@ the allowed maximum is .Dv RES_MAXRETRY (see .In resolv.h ) . +.It Sy edns0 +Sets +.Dv RES_USE_EDNS0 . +Attach an OPT pseudo-RR for the EDNS0 extension, +as specified in RFC 2671. +This allows the resolver to advertise a larger UDP receive buffer size, +permitting responses larger than the original 512-byte limit. +.It Sy inet6 +Sets +.Dv RES_USE_INET6 . +Causes +.Xr gethostbyname 3 +to look up AAAA records before A records +and to map IPv4 responses into IPv6 addresses. +The use of this option is discouraged. +.It Sy insecure1 +Sets +.Dv RES_INSECURE1 . +Disables the check that the response was received from the +same server to which the query was sent. +Use of this option is a security risk and is not recommended. +.It Sy insecure2 +Sets +.Dv RES_INSECURE2 . +Disables the check that the response contains a query +matching the one that was sent. +Use of this option is a security risk and is not recommended. +.It Sy no-check-names +Sets +.Dv RES_NOCHECKNAME . +Disables the check of incoming host names for invalid characters +such as underscore, non-ASCII, or control characters. .It Sy no_tld_query tells the resolver not to attempt to resolve a top level domain name, that is, a name that contains no dots. @@ -179,6 +211,12 @@ the resolver from obeying the standard and .Sy search rules with the given name. +.It Sy rotate +Sets +.Dv RES_ROTATE . +Causes the resolver to round-robin among the configured name servers, +distributing the query load instead of always trying the first +listed server. .It Sy reload-period : Ns Ar n The resolver checks the modification time of .Pa /etc/resolv.conf