[IPV6] XFRM: probe icmpv6 type/code when sending packets via raw socket.

Signed-off-by: Masahide Nakamura <nakam@linux-ipv6.org>
Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>

net/ipv6/raw.c

@@ -555,6 +555,52 @@ static int rawv6_send_hdrinc(struct sock *sk, void *from, int length,
 	IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
 	return err; 
 }
+
+static void rawv6_probe_proto_opt(struct flowi *fl, struct msghdr *msg)
+{
+	struct iovec *iov;
+	u8 *type = NULL;
+	u8 *code = NULL;
+	int probed = 0;
+	int i;
+
+	if (!msg->msg_iov)
+		return;
+
+	for (i = 0; i < msg->msg_iovlen; i++) {
+		iov = &msg->msg_iov[i];
+		if (!iov)
+			continue;
+
+		switch (fl->proto) {
+		case IPPROTO_ICMPV6:
+			/* check if one-byte field is readable or not. */
+			if (iov->iov_base && iov->iov_len < 1)
+				break;
+
+			if (!type) {
+				type = iov->iov_base;
+				/* check if code field is readable or not. */
+				if (iov->iov_len > 1)
+					code = type + 1;
+			} else if (!code)
+				code = iov->iov_base;
+
+			if (type && code) {
+				fl->fl_icmp_type = *type;
+				fl->fl_icmp_code = *code;
+				probed = 1;
+			}
+			break;
+		default:
+			probed = 1;
+			break;
+		}
+		if (probed)
+			break;
+	}
+}
+
 static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
 		   struct msghdr *msg, size_t len)
 {
@@ -674,6 +720,8 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
 
 	fl.proto = proto;
+	rawv6_probe_proto_opt(&fl, msg);
+ 
 	ipv6_addr_copy(&fl.fl6_dst, daddr);
 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);