libnetlink: change rtnl_send() to take void *

Avoid having to cast buffer being sent.

genl/ctrl.c

@@ -350,7 +350,7 @@ static int ctrl_list(int cmd, int argc, char **argv)
 		nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
 		nlh->nlmsg_seq = rth.dump = ++rth.seq;
 
-		if (rtnl_send(&rth, (const char *) nlh, nlh->nlmsg_len) < 0) {
+		if (rtnl_send(&rth, nlh, nlh->nlmsg_len) < 0) {
 			perror("Failed to send dump request\n");
 			goto ctrl_done;
 		}

include/libnetlink.h

@@ -47,8 +47,8 @@ extern int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
 		     unsigned groups, struct nlmsghdr *answer,
 		     rtnl_filter_t junk,
 		     void *jarg);
-extern int rtnl_send(struct rtnl_handle *rth, const char *buf, int);
-extern int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int);
+extern int rtnl_send(struct rtnl_handle *rth, const void *buf, int);
+extern int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int);
 
 extern int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data);
 extern int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data, int alen);

ip/iplink.c

@@ -164,7 +164,7 @@ static int iplink_have_newlink(void)
 		req.n.nlmsg_type = RTM_NEWLINK;
 		req.i.ifi_family = AF_UNSPEC;
 
-		rtnl_send(&rth, (char *)&req.n, req.n.nlmsg_len);
+		rtnl_send(&rth, &req.n, req.n.nlmsg_len);
 		rtnl_listen(&rth, accept_msg, NULL);
 	}
 	return have_rtnl_newlink;

lib/libnetlink.c

@@ -107,12 +107,12 @@ int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
 	return send(rth->fd, (void*)&req, sizeof(req), 0);
 }
 
-int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
+int rtnl_send(struct rtnl_handle *rth, const void *buf, int len)
 {
 	return send(rth->fd, buf, len, 0);
 }
 
-int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int len)
+int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
 {
 	struct nlmsghdr *h;
 	int status;
@@ -148,7 +148,7 @@ int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int len)
 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
 {
 	struct nlmsghdr nlh;
-	struct sockaddr_nl nladdr;
+	struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 	struct iovec iov[2] = {
 		{ .iov_base = &nlh, .iov_len = sizeof(nlh) },
 		{ .iov_base = req, .iov_len = len }
@@ -160,9 +160,6 @@ int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
 		.msg_iovlen = 2,
 	};
 
-	memset(&nladdr, 0, sizeof(nladdr));
-	nladdr.nl_family = AF_NETLINK;
-
 	nlh.nlmsg_len = NLMSG_LENGTH(len);
 	nlh.nlmsg_type = type;
 	nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;

misc/arpd.c

@@ -281,7 +281,7 @@ int respond_to_kernel(int ifindex, __u32 addr, char *lla, int llalen)
 
 	addattr_l(&req.n, sizeof(req), NDA_DST, &addr, 4);
 	addattr_l(&req.n, sizeof(req), NDA_LLADDR, lla, llalen);
-	return rtnl_send(&rth, (char*)&req, req.n.nlmsg_len) <= 0;
+	return rtnl_send(&rth, &req, req.n.nlmsg_len) <= 0;
 }
 
 void prepare_neg_entry(__u8 *ndata, __u32 stamp)