declare IP6_EXTHDR_GET{,0}. sorry i forgot to commit this one.

1 files changed, 54 insertions, 4 deletions

diff --git a/sys/netinet/ip6.h b/sys/netinet/ip6.h
index 0f9d7a4490f..15417526748 100644
--- a/sys/netinet/ip6.h
+++ b/sys/netinet/ip6.h
@@ -1,9 +1,10 @@
-/*	$OpenBSD: ip6.h,v 1.3 2000/02/24 11:37:49 itojun Exp $	*/
+/*	$OpenBSD: ip6.h,v 1.4 2000/06/13 01:17:13 itojun Exp $	*/
+/*	$KAME: ip6.h,v 1.7 2000/03/25 07:23:36 sumikawa Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  * All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -15,7 +16,7 @@
  * 3. Neither the name of the project nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
@@ -80,7 +81,7 @@ struct ip6_hdr {
 			u_int8_t  ip6_un1_nxt;	/* next header */
 			u_int8_t  ip6_un1_hlim;	/* hop limit */
 		} ip6_un1;
-		u_int8_t ip6_un2_vfc;	/* 4 bits version, 4 bits class */
+		u_int8_t ip6_un2_vfc;	/* 4 bits version, top 4 bits class */
 	} ip6_ctlun;
 	struct in6_addr ip6_src;	/* source address */
 	struct in6_addr ip6_dst;	/* destination address */
@@ -246,6 +247,55 @@ do {									\
 	}								\
     }									\
 } while (0)
+
+/*
+ * IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
+ * "len") is located in single mbuf, on contiguous memory region.
+ * The pointer to the region will be returned to pointer variable "val",
+ * with type "typ".
+ * IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
+ * very top of mbuf.  GET0 is likely to make memory copy than GET.
+ *
+ * XXX we're now testing this, needs m_pulldown()
+ */
+#define IP6_EXTHDR_GET(val, typ, m, off, len) \
+do {									\
+	struct mbuf *t;							\
+	int tmp;							\
+	ip6stat.ip6s_exthdrget++;					\
+	if ((m)->m_len >= (off) + (len))				\
+		(val) = (typ)(mtod((m), caddr_t) + (off));		\
+	else {								\
+		t = m_pulldown((m), (off), (len), &tmp);		\
+		if (t) {						\
+			if (t->m_len < tmp + (len))			\
+				panic("m_pulldown malfunction");	\
+			(val) = (typ)(mtod(t, caddr_t) + tmp);		\
+		} else {						\
+			(val) = (typ)NULL;				\
+			(m) = NULL;					\
+		}							\
+	}								\
+} while (0)
+
+#define IP6_EXTHDR_GET0(val, typ, m, off, len) \
+do {									\
+	struct mbuf *t;							\
+	ip6stat.ip6s_exthdrget0++;					\
+	if ((off) == 0)							\
+		(val) = (typ)mtod(m, caddr_t);				\
+	else {								\
+		t = m_pulldown((m), (off), (len), NULL);		\
+		if (t) {						\
+			if (t->m_len < (len))				\
+				panic("m_pulldown malfunction");	\
+			(val) = (typ)mtod(t, caddr_t);			\
+		} else {						\
+			(val) = (typ)NULL;				\
+			(m) = NULL;					\
+		}							\
+	}								\
+} while (0)
 #endif /*_KERNEL*/
 
 #endif /* not _NETINET_IP6_H_ */