netlink socket does not accept SOCK_DGRAM

[User Ngor]

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 
r...@releng1.nyi.freebsd.org:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64

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


--
Ihor Antonov