Add a "fork" of musl as //fusl.

fusl/src/network/netlink.c

Index: fusl/src/network/netlink.c
diff --git a/fusl/src/network/netlink.c b/fusl/src/network/netlink.c
new file mode 100644
index 0000000000000000000000000000000000000000..94dba7f5c9e40d47b92f35b67790ee188221838f
--- /dev/null
+++ b/fusl/src/network/netlink.c
@@ -0,0 +1,52 @@
+#include <errno.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/socket.h>
+#include "netlink.h"
+
+static int __netlink_enumerate(int fd, unsigned int seq, int type, int af,
+	int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx)
+{
+	struct nlmsghdr *h;
+	union {
+		uint8_t buf[8192];
+		struct {
+			struct nlmsghdr nlh;
+			struct rtgenmsg g;
+		} req;
+		struct nlmsghdr reply;
+	} u;
+	int r, ret;
+
+	memset(&u.req, 0, sizeof(u.req));
+	u.req.nlh.nlmsg_len = sizeof(u.req);
+	u.req.nlh.nlmsg_type = type;
+	u.req.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
+	u.req.nlh.nlmsg_seq = seq;
+	u.req.g.rtgen_family = af;
+	r = send(fd, &u.req, sizeof(u.req), 0);
+	if (r < 0) return r;
+
+	while (1) {
+		r = recv(fd, u.buf, sizeof(u.buf), MSG_DONTWAIT);
+		if (r <= 0) return -1;
+		for (h = &u.reply; NLMSG_OK(h, (void*)&u.buf[r]); h = NLMSG_NEXT(h)) {
+			if (h->nlmsg_type == NLMSG_DONE) return 0;
+			if (h->nlmsg_type == NLMSG_ERROR) return -1;
+			ret = cb(ctx, h);
+			if (ret) return ret;
+		}
+	}
+}
+
+int __rtnetlink_enumerate(int link_af, int addr_af, int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx)
+{
+	int fd, r;
+
+	fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_ROUTE);
+	if (fd < 0) return -1;
+	r = __netlink_enumerate(fd, 1, RTM_GETLINK, link_af, cb, ctx);
+	if (!r) r = __netlink_enumerate(fd, 2, RTM_GETADDR, addr_af, cb, ctx);
+	__syscall(SYS_close,fd);
+	return r;
+}