git: 64dfea86515e - main - netlink: add NETLINK/NETLINK_SUPPORT userland options.

From: Alexander V. Chernikov <melifaro_at_FreeBSD.org>
Date: Sun, 26 Mar 2023 09:00:20 UTC
The branch main has been updated by melifaro:

URL: https://cgit.FreeBSD.org/src/commit/?id=64dfea86515e71af254cf90d6d5ceb689b8fbf5a

commit 64dfea86515e71af254cf90d6d5ceb689b8fbf5a
Author:     Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2023-03-26 08:56:49 +0000
Commit:     Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2023-03-26 08:59:58 +0000

    netlink: add NETLINK/NETLINK_SUPPORT userland options.
    
    Make userland tools such as netstat, route, arp and ndp use
     either netlink or rtsock interfaces based on the NETLINK_SUPPORT
     options.
    Both NETLINK and NETLINK_SUPPORT options are turned on by default.
    
    Reviewed By: eugen
    Differential Revision: https://reviews.freebsd.org/D39148
---
 share/mk/src.opts.mk                        |  2 ++
 tools/build/options/WITHOUT_NETLINK_SUPPORT |  5 +++++
 usr.bin/netstat/Makefile                    |  7 ++++++-
 usr.bin/netstat/route.c                     | 13 +++++++++++--
 4 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/share/mk/src.opts.mk b/share/mk/src.opts.mk
index 880f1139843c..7c73e66aba18 100644
--- a/share/mk/src.opts.mk
+++ b/share/mk/src.opts.mk
@@ -145,6 +145,7 @@ __DEFAULT_YES_OPTIONS = \
     MLX5TOOL \
     NETCAT \
     NETGRAPH \
+    NETLINK \
     NLS_CATALOGS \
     NS_CACHING \
     NTP \
@@ -233,6 +234,7 @@ __DEFAULT_DEPENDENT_OPTIONS= \
     KERBEROS \
     KVM \
     NETGRAPH \
+    NETLINK \
     PAM \
     TESTS \
     WIRELESS
diff --git a/tools/build/options/WITHOUT_NETLINK_SUPPORT b/tools/build/options/WITHOUT_NETLINK_SUPPORT
new file mode 100644
index 000000000000..4a72d3f1e4d1
--- /dev/null
+++ b/tools/build/options/WITHOUT_NETLINK_SUPPORT
@@ -0,0 +1,5 @@
+.\" $FreeBSD$
+Make libraries and programs use rtsock and
+.Xr sysctl 3
+interfaces instead of
+.Xr snl 3 .
diff --git a/usr.bin/netstat/Makefile b/usr.bin/netstat/Makefile
index e2c9ca09eea5..92f8aa9c30fa 100644
--- a/usr.bin/netstat/Makefile
+++ b/usr.bin/netstat/Makefile
@@ -6,7 +6,6 @@
 PROG=	netstat
 SRCS=	if.c inet.c main.c mbuf.c mroute.c netisr.c nl_symbols.c route.c \
 	unix.c mroute6.c ipsec.c bpf.c pfkey.c sctp.c common.c nhops.c nhgrp.c \
-	route_netlink.c \
 	nl_defs.h
 
 nl_symbols.c: nlist_symbols
@@ -64,4 +63,10 @@ LIBADD+=	netgraph
 CFLAGS+=-DNETGRAPH
 .endif
 
+.if ${MK_NETLINK_SUPPORT} != "no"
+SRCS+=	route_netlink.c
+.else
+CFLAGS+=-DWITHOUT_NETLINK
+.endif
+
 .include <bsd.prog.mk>
diff --git a/usr.bin/netstat/route.c b/usr.bin/netstat/route.c
index 5de683ebfe7a..c597f3632fa6 100644
--- a/usr.bin/netstat/route.c
+++ b/usr.bin/netstat/route.c
@@ -96,16 +96,20 @@ struct bits rt_bits[] = {
 	{ 0 , 0, NULL }
 };
 
+#ifdef WITHOUT_NETLINK
 static struct ifmap_entry *ifmap;
 static size_t ifmap_size;
+#endif
 static struct timespec uptime;
 
 static const char *netname4(in_addr_t, in_addr_t);
 #ifdef INET6
 static const char *netname6(struct sockaddr_in6 *, struct sockaddr_in6 *);
 #endif
+#ifdef WITHOUT_NETLINK
 static void p_rtable_sysctl(int, int);
 static void p_rtentry_sysctl(const char *name, struct rt_msghdr *);
+#endif
 static void domask(char *, size_t, u_long);
 
 const uint32_t rt_default_weight = RT_DEFAULT_WEIGHT;
@@ -143,8 +147,11 @@ routepr(int fibnum, int af)
 	if (fibnum)
 		xo_emit(" ({L:fib}: {:fib/%d})", fibnum);
 	xo_emit("\n");
-	if (!p_rtable_netlink(fibnum, af))
-		p_rtable_sysctl(fibnum, af);
+#ifdef WITHOUT_NETLINK
+	p_rtable_sysctl(fibnum, af);
+#else
+	p_rtable_netlink(fibnum, af);
+#endif
 	xo_close_container("route-information");
 }
 
@@ -240,6 +247,7 @@ set_wid(int fam)
 	wid.expire = 6;
 }
 
+#ifdef WITHOUT_NETLINK
 static void
 p_rtable_sysctl(int fibnum, int af)
 {
@@ -365,6 +373,7 @@ p_rtentry_sysctl(const char *name, struct rt_msghdr *rtm)
 	xo_emit("\n");
 	xo_close_instance(name);
 }
+#endif
 
 int
 p_sockaddr(const char *name, struct sockaddr *sa, struct sockaddr *mask,