netlink socket does not accept SOCK_DGRAM

man 4 rtnetlink says:

     int socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);



The following snippet fails

     int fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
     if (fd < 0) {
         perror("Failed to open netlink socket");
         return -1;
     }
     printf("all good\n");
     close(fd);
     return 0;

I get: Failed to open netlink socket: Protocol wrong type for socket


but if I change
	int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);

I get "all good"

Am I doing something wrong or is this a bug?



$ uname -a FreeBSD zen.hq 14.0-CURRENT FreeBSD 14.0-CURRENT #0 
main-n259967-11b5b9e8a520: Sat Jan  7 16:39:30 UTC 2023 
root@releng1.nyi.freebsd.org:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64

$ kldstat | grep netl
39    1 0xffffffff839fc000    14af8 netlink.ko


-- 
Ihor Antonov