Assume IPV6_V6ONLY is universally available

In 2024, IPV6_V6ONLY socket option is either available or the operating
system is just not going to be supported.

diff --git a/lib/isc/include/isc/net.h b/lib/isc/include/isc/net.h
index eda799c60d255a023562b42c6d83a327eeebc318..322584c3af3d0e0417fd4c9c95af5dc28c0ad548 100644 (file)
--- a/lib/isc/include/isc/net.h
+++ b/lib/isc/include/isc/net.h
@@ -211,18 +211,6 @@ isc_net_probeipv6(void);
  *\li  #ISC_R_UNEXPECTED
  */
 
-isc_result_t
-isc_net_probe_ipv6only(void);
-/*%<
- * Check if the system's kernel supports the IPV6_V6ONLY socket option.
- *
- * Returns:
- *
- *\li  #ISC_R_SUCCESS          the option is supported for both TCP and UDP.
- *\li  #ISC_R_NOTFOUND         IPv6 itself or the option is not supported.
- *\li  #ISC_R_UNEXPECTED
- */
-
 isc_result_t
 isc_net_probe_ipv6pktinfo(void);
 /*

diff --git a/lib/isc/net.c b/lib/isc/net.c
index adae0fef83ecad099efeadfa05154e4f0edcf4a7..d0ab37316bc70e4fa692fedc8ad90bcd84b3c6c4 100644 (file)
--- a/lib/isc/net.c
+++ b/lib/isc/net.c
@@ -89,7 +89,6 @@
 
 #endif /* HAVE_SYSCTLBYNAME */
 
-static isc_once_t once_ipv6only = ISC_ONCE_INIT;
 #ifdef __notyet__
 static isc_once_t once_ipv6pktinfo = ISC_ONCE_INIT;
 #endif /* ifdef __notyet__ */
@@ -106,7 +105,6 @@ static isc_once_t once = ISC_ONCE_INIT;
 
 static isc_result_t ipv4_result = ISC_R_NOTFOUND;
 static isc_result_t ipv6_result = ISC_R_NOTFOUND;
-static isc_result_t ipv6only_result = ISC_R_NOTFOUND;
 static isc_result_t ipv6pktinfo_result = ISC_R_NOTFOUND;
 
 static isc_result_t
@@ -200,66 +198,6 @@ isc_net_probeipv6(void) {
        return ipv6_result;
 }
 
-static void
-try_ipv6only(void) {
-#ifdef IPV6_V6ONLY
-       int s, on;
-#endif /* ifdef IPV6_V6ONLY */
-       isc_result_t result;
-
-       result = isc_net_probeipv6();
-       if (result != ISC_R_SUCCESS) {
-               ipv6only_result = result;
-               return;
-       }
-
-#ifndef IPV6_V6ONLY
-       ipv6only_result = ISC_R_NOTFOUND;
-       return;
-#else  /* ifndef IPV6_V6ONLY */
-       /* check for TCP sockets */
-       s = socket(PF_INET6, SOCK_STREAM, 0);
-       if (s == -1) {
-               UNEXPECTED_SYSERROR(errno, "socket()");
-               ipv6only_result = ISC_R_UNEXPECTED;
-               return;
-       }
-
-       on = 1;
-       if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {
-               ipv6only_result = ISC_R_NOTFOUND;
-               goto close;
-       }
-
-       close(s);
-
-       /* check for UDP sockets */
-       s = socket(PF_INET6, SOCK_DGRAM, 0);
-       if (s == -1) {
-               UNEXPECTED_SYSERROR(errno, "socket()");
-               ipv6only_result = ISC_R_UNEXPECTED;
-               return;
-       }
-
-       on = 1;
-       if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {
-               ipv6only_result = ISC_R_NOTFOUND;
-               goto close;
-       }
-
-       ipv6only_result = ISC_R_SUCCESS;
-
-close:
-       close(s);
-       return;
-#endif /* IPV6_V6ONLY */
-}
-
-static void
-initialize_ipv6only(void) {
-       isc_once_do(&once_ipv6only, try_ipv6only);
-}
-
 #ifdef __notyet__
 static void
 try_ipv6pktinfo(void) {
@@ -305,12 +243,6 @@ initialize_ipv6pktinfo(void) {
 }
 #endif /* ifdef __notyet__ */
 
-isc_result_t
-isc_net_probe_ipv6only(void) {
-       initialize_ipv6only();
-       return ipv6only_result;
-}
-
 isc_result_t
 isc_net_probe_ipv6pktinfo(void) {
 /*

diff --git a/lib/ns/interfacemgr.c b/lib/ns/interfacemgr.c
index 836ee05a853c4a143f11249d6bfc22ef75aef1d5..7902b1a0da934f77d70d88481fc9cb9b62aa641e 100644 (file)
--- a/lib/ns/interfacemgr.c
+++ b/lib/ns/interfacemgr.c
@@ -1085,7 +1085,6 @@ do_scan(ns_interfacemgr_t *mgr, bool verbose, bool config) {
        isc_interfaceiter_t *iter = NULL;
        bool scan_ipv4 = false;
        bool scan_ipv6 = false;
-       bool ipv6only = true;
        bool ipv6pktinfo = true;
        isc_result_t result;
        isc_netaddr_t zero_address, zero_address6;
@@ -1124,15 +1123,11 @@ do_scan(ns_interfacemgr_t *mgr, bool verbose, bool config) {
         * packets as the form of mapped addresses unintentionally
         * unless explicitly allowed.
         */
-       if (scan_ipv6 && isc_net_probe_ipv6only() != ISC_R_SUCCESS) {
-               ipv6only = false;
-               log_explicit = true;
-       }
        if (scan_ipv6 && isc_net_probe_ipv6pktinfo() != ISC_R_SUCCESS) {
                ipv6pktinfo = false;
                log_explicit = true;
        }
-       if (scan_ipv6 && ipv6only && ipv6pktinfo) {
+       if (scan_ipv6 && ipv6pktinfo) {
                for (le = ISC_LIST_HEAD(mgr->listenon6->elts); le != NULL;
                     le = ISC_LIST_NEXT(le, link))
                {
@@ -1283,7 +1278,7 @@ do_scan(ns_interfacemgr_t *mgr, bool verbose, bool config) {
                         * The case of "any" IPv6 address will require
                         * special considerations later, so remember it.
                         */
-                       if (family == AF_INET6 && ipv6only && ipv6pktinfo &&
+                       if (family == AF_INET6 && ipv6pktinfo &&
                            listenon_is_ip6_any(le))
                        {
                                ipv6_wildcard = true;