Introduce API for sequential reads/writes (build/dissect) of mbuf chains.

Reviewed by:	Ian Dowse <iedowse@maths.tcd.ie>,
		Bosko Milekic <bmilekic@technokratis.com>,
		Julian Elischer <julian@elischer.org> and arch@/net@
Obtained from:	smbfs

1 files changed, 155 insertions, 0 deletions

diff --git a/sys/sys/mchain.h b/sys/sys/mchain.h
new file mode 100644
index 0000000..e79fbfb
--- /dev/null
+++ b/sys/sys/mchain.h
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2000, 2001 Boris Popov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    This product includes software developed by Boris Popov.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#ifndef _SYS_MCHAIN_H_
+#define _SYS_MCHAIN_H_
+
+#include <machine/endian.h>
+
+/*
+ * This macros probably belongs to the endian.h
+ */
+#if (BYTE_ORDER == LITTLE_ENDIAN)
+
+#define htoles(x)	((u_int16_t)(x))
+#define letohs(x)	((u_int16_t)(x))
+#define	htolel(x)	((u_int32_t)(x))
+#define	letohl(x)	((u_int32_t)(x))
+#define	htoleq(x)	((int64_t)(x))
+#define	letohq(x)	((int64_t)(x))
+
+#define htobes(x)	(htons(x))
+#define betohs(x)	(ntohs(x))
+#define htobel(x)	(htonl(x))
+#define betohl(x)	(ntohl(x))
+
+static __inline int64_t
+htobeq(int64_t x)
+{
+	return (int64_t)htonl((u_int32_t)(x >> 32)) |
+	    (int64_t)htonl((u_int32_t)(x & 0xffffffff)) << 32;
+}
+
+static __inline int64_t
+betohq(int64_t x)
+{
+	return (int64_t)ntohl((u_int32_t)(x >> 32)) |
+	    (int64_t)ntohl((u_int32_t)(x & 0xffffffff)) << 32;
+}
+
+#else	/* (BYTE_ORDER == LITTLE_ENDIAN) */
+
+#error "Macros for Big-Endians are incomplete"
+
+/*
+#define htoles(x)	((u_int16_t)(x))
+#define letohs(x)	((u_int16_t)(x))
+#define	htolel(x)	((u_int32_t)(x))
+#define	letohl(x)	((u_int32_t)(x))
+*/
+#endif	/* (BYTE_ORDER == LITTLE_ENDIAN) */
+
+
+#ifdef _KERNEL
+
+/*
+ * Type of copy for mb_{put|get}_mem()
+ */
+#define	MB_MSYSTEM	0		/* use bcopy() */
+#define MB_MUSER	1		/* use copyin()/copyout() */
+#define MB_MINLINE	2		/* use an inline copy loop */
+#define	MB_MZERO	3		/* bzero(), mb_put_mem only */
+#define	MB_MCUSTOM	4		/* use an user defined function */
+
+struct mbuf;
+struct mbchain;
+
+typedef int mb_copy_t(struct mbchain *mbp, c_caddr_t src, caddr_t dst, int len);
+
+struct mbchain {
+	struct mbuf *	mb_top;		/* head of mbufs chain */
+	struct mbuf * 	mb_cur;		/* current mbuf */
+	int		mb_mleft;	/* free space in the current mbuf */
+	int		mb_count;	/* total number of bytes */
+	mb_copy_t *	mb_copy;	/* user defined copy function */
+	void *		mb_udata;	/* user data */
+};
+
+struct mdchain {
+	struct mbuf *	md_top;		/* head of mbufs chain */
+	struct mbuf * 	md_cur;		/* current mbuf */
+	u_char *	md_pos;		/* offset in the current mbuf */
+};
+
+int  m_fixhdr(struct mbuf *m);
+
+int  mb_init(struct mbchain *mbp);
+void mb_initm(struct mbchain *mbp, struct mbuf *m);
+void mb_done(struct mbchain *mbp);
+struct mbuf *mb_detach(struct mbchain *mbp);
+int  mb_fixhdr(struct mbchain *mbp);
+caddr_t mb_reserve(struct mbchain *mbp, int size);
+
+int  mb_put_uint8(struct mbchain *mbp, u_int8_t x);
+int  mb_put_uint16be(struct mbchain *mbp, u_int16_t x);
+int  mb_put_uint16le(struct mbchain *mbp, u_int16_t x);
+int  mb_put_uint32be(struct mbchain *mbp, u_int32_t x);
+int  mb_put_uint32le(struct mbchain *mbp, u_int32_t x);
+int  mb_put_int64be(struct mbchain *mbp, int64_t x);
+int  mb_put_int64le(struct mbchain *mbp, int64_t x);
+int  mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type);
+int  mb_put_mbuf(struct mbchain *mbp, struct mbuf *m);
+int  mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size);
+
+int  md_init(struct mdchain *mdp);
+void md_initm(struct mdchain *mbp, struct mbuf *m);
+void md_done(struct mdchain *mdp);
+void md_append_record(struct mdchain *mdp, struct mbuf *top);
+int  md_next_record(struct mdchain *mdp);
+int  md_get_uint8(struct mdchain *mdp, u_int8_t *x);
+int  md_get_uint16(struct mdchain *mdp, u_int16_t *x);
+int  md_get_uint16le(struct mdchain *mdp, u_int16_t *x);
+int  md_get_uint16be(struct mdchain *mdp, u_int16_t *x);
+int  md_get_uint32(struct mdchain *mdp, u_int32_t *x);
+int  md_get_uint32be(struct mdchain *mdp, u_int32_t *x);
+int  md_get_uint32le(struct mdchain *mdp, u_int32_t *x);
+int  md_get_int64(struct mdchain *mdp, int64_t *x);
+int  md_get_int64be(struct mdchain *mdp, int64_t *x);
+int  md_get_int64le(struct mdchain *mdp, int64_t *x);
+int  md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type);
+int  md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **m);
+int  md_get_uio(struct mdchain *mdp, struct uio *uiop, int size);
+
+#endif	/* ifdef _KERNEL */
+
+#endif	/* !_SYS_MCHAIN_H_ */