os dependency glue file for improving portability

Submitted by:	<jonathan@decru.com>
Supported by:	FreeBSD Foundation
Obtained from:	NetBSD

1 files changed, 307 insertions, 0 deletions

diff --git a/sys/netipsec/ipsec_osdep.h b/sys/netipsec/ipsec_osdep.h
new file mode 100644
index 0000000..86bef77
--- /dev/null
+++ b/sys/netipsec/ipsec_osdep.h
@@ -0,0 +1,307 @@
+/*	$FreeBSD$	*/
+/*	$NetBSD: ipsec_osdep.h,v 1.1 2003/08/13 20:06:51 jonathan Exp $	*/
+
+/*
+ * Copyright (c) 2003 Jonathan Stone (jonathan@cs.stanford.edu)
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
+ */
+
+#ifndef NETIPSEC_OSDEP_H
+#define NETIPSEC_OSDEP_H
+
+/* 
+ *  Hide porting differences across different 4.4BSD-derived platforms.
+ * 
+ * 1.  KASSERT() differences: 
+ * 2.  Kernel  Random-number API differences.
+ * 3.  Is packet data in an mbuf object writeable?
+ * 4.  Packet-header semantics.
+ * 5.  Fast mbuf-cluster allocation.
+ * 6.  Network packet-output macros.
+ * 7.  Elased time, in seconds.
+ * 8.  Test if a  socket object opened by  a privileged (super) user.
+ * 9.  Global SLIST of all open raw sockets.
+ * 10. Global SLIST of known interface addresses.
+ */
+
+/*
+ *  1. KASSERT and spl differences 
+ *
+ * FreeBSD takes an expression and  parenthesized printf() argument-list.
+ * NetBSD takes one arg: the expression being asserted.
+ * FreeBSD's SPLASSERT() takes an SPL level as 1st arg and a
+ * parenthesized printf-format argument list as the second argument.
+ *
+ * This difference is hidden by two 2-argument macros and one 1-arg macro:
+ *    IPSEC_ASSERT(expr, msg)
+ *    IPSEC_SPLASSERT(spl, msg)
+ * One further difference is the spl names:
+ *    NetBSD splsoftnet equates to FreeBSD splnet;
+ *    NetBSD splnet equates to FreeBSD splimp.
+ * which is hidden by the macro IPSEC_SPLASSERT_SOFTNET(msg).
+ */
+#ifdef __FreeBSD__
+#if __FreeBSD_version < 500000
+#define IPSEC_SPLASSERT(_x,_y) SPLASSERT(_x, _y)
+#else
+#define IPSEC_SPLASSERT(_x,_y)
+#endif
+#define IPSEC_SPLASSERT_SOFTNET(_m) IPSEC_SPLASSERT(net,_m)
+#define IPSEC_ASSERT(_c,_m) KASSERT(_c, _m)
+#endif	/* __FreeBSD__ */
+
+#ifdef	__NetBSD__
+#define IPSEC_SPLASSERT(x,y) (void)0
+#define IPSEC_ASSERT(c,m) KASSERT(c)
+#define IPSEC_SPLASSERT_SOFTNET(m) IPSEC_SPLASSERT(softnet, m)
+#endif	/* __NetBSD__ */
+
+/*
+ * 2. Kernel Randomness API.
+ * FreeBSD uses:
+ *    u_int read_random(void *outbuf, int nbytes).
+ */
+#ifdef __FreeBSD__
+#include <sys/random.h>
+/* do nothing, use native random code. */
+#endif /* __FreeBSD__ */
+
+#ifdef	__NetBSD__
+#include <sys/rnd.h>
+static __inline u_int read_random(void *p, u_int len);
+
+static __inline u_int
+read_random(void *bufp, u_int len) 
+{ 
+	return rnd_extract_data(bufp, len, RND_EXTRACT_ANY /*XXX FIXME */);
+}
+#endif	/* __NetBSD__ */
+
+/*
+ * 3. Test for mbuf mutability
+ * FreeBSD 4.x uses: M_EXT_WRITABLE
+ * NetBSD has M_READONLY(). Use !M_READONLY().
+ * Not an exact match to FreeBSD semantics, but adequate for IPsec purposes.
+ * 
+ */
+#ifdef __NetBSD__
+/* XXX wrong, but close enough for restricted ipsec usage. */
+#define M_EXT_WRITABLE(m) (!M_READONLY(m))
+#endif	/* __NetBSD__ */
+
+/*
+ * 4. mbuf packet-header/packet-tag semantics.
+ * Sam Leffler explains, in private email, some problems with
+ * M_COPY_PKTHDR(), and why FreeBSD deprecated it and replaced it
+ * with new, explicit macros M_MOVE_PKTHDR()/M_DUP_PKTHDR().
+ * he original fast-ipsec source uses M_MOVE_PKTHDR.
+ * NetBSD currently still uses M_COPY_PKTHDR(), so we define
+ * M_MOVE_PKTHDR in terms of M_COPY_PKTHDR().  Fast-IPsec
+ * will delete the source mbuf shortly after copying packet tags,
+ * so we are safe for fast-ipsec but not in general..
+ */
+#ifdef __NetBSD__
+#define M_MOVE_PKTHDR(_f, _t) M_COPY_PKTHDR(_f, _t)
+#endif /* __NetBSD__ */
+
+
+/*
+ * 5. Fast mbuf-cluster allocation.
+ * FreeBSD 4.6 introduce m_getcl(), which performs `fast' allocation
+ * mbuf clusters from a cache of recently-freed clusters. (If the  cache
+ * is empty, new clusters are allocated en-masse).
+ *   On NetBSD, for now, implement the `cache' as an inline  function
+ *using normal NetBSD mbuf/cluster allocation macros. Replace this
+ * with fast-cache code, if and when netBSD  implements one.
+ */
+#ifdef __NetBSD__
+static __inline struct mbuf *
+m_getcl(int how, short type, int flags)
+{
+	struct mbuf *mp;
+	if (flags & M_PKTHDR) 
+		MGETHDR(mp, how, type);
+	else
+		MGET(mp, how,  type);
+	if (mp == NULL)
+		return NULL;
+
+	MCLGET(mp, how);
+	return mp;
+}
+#endif /* __NetBSD__ */
+
+/*
+ * 6. Network output macros
+ * FreeBSD uses the  IF_HANDOFF(), which raises SPL, enqueues
+ * a packet, and updates interface counters. NetBSD has IFQ_ENQUE(),
+ * which leaves SPL changes up to the caller. 
+ * For now, we provide an emulation of IF_HANOOFF() which works
+ * for protocol input queues.
+ */
+#ifdef __FreeBSD__ 
+/* nothing to do */
+#endif /* __FreeBSD__ */
+#ifdef __NetBSD__
+#define IF_HANDOFF(ifq, m, f) if_handoff(ifq, m, f, 0)
+  
+#include <net/if.h>
+
+static __inline int
+if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp, int adjust)
+{
+	int need_if_start = 0;
+	int s = splnet();
+
+	if (IF_QFULL(ifq)) {
+		IF_DROP(ifq);
+		splx(s);
+		m_freem(m);
+		return (0);
+	}
+	if (ifp != NULL) {
+		ifp->if_obytes += m->m_pkthdr.len + adjust;
+		if (m->m_flags & M_MCAST)
+			ifp->if_omcasts++;
+		need_if_start = !(ifp->if_flags & IFF_OACTIVE);
+	}
+	IF_ENQUEUE(ifq, m);
+	if (need_if_start)
+		(*ifp->if_start)(ifp);
+	splx(s);
+	return (1);
+}
+#endif /* __NetBSD__ */
+
+/*
+ * 7. Elapsed Time: time_second as time in seconds.
+ * Original FreeBSD fast-ipsec code references a FreeBSD kernel global,
+ * time_second().  NetBSD: kludge #define to use time_mono_time.tv_sec.
+ */
+#ifdef __NetBSD__
+#include <sys/kernel.h>
+#define time_second mono_time.tv_sec
+#endif	/* __NetBSD__ */
+
+/* protosw glue */
+#ifdef __NetBSD__
+#include <sys/protosw.h>
+#define ipprotosw protosw
+#endif	/* __NetBSD__ */
+
+/*
+ * 8. Test for "privileged" socket opened by superuser.
+ * FreeBSD tests  ((so)->so_cred && (so)->so_cred.cr_uid == 0), 
+ * NetBSD (1.6N) tests (so)->so_uid == 0).
+ * This difference is wrapped inside  the IPSEC_PRIVILEGED_SO() macro.
+ *
+ */
+#ifdef __FreeBSD__ 
+#define IPSEC_IS_PRIVILEGED_SO(_so) \
+	((_so)->so_cred && (_so)->so_cred->cr_uid == 0)
+#endif	/* __FreeBSD__ */
+
+#ifdef __NetBSD__
+/* superuser opened socket? */
+#define IPSEC_IS_PRIVILEGED_SO(so) ((so)->so_uid == 0)
+#endif	/* __NetBSD__ */
+
+/*
+ * 9. Raw socket list
+ * FreeBSD uses: listhead = rawcb_list, SLIST()-next field "list".
+ * NetBSD  uses: listhead = rawcb, SLIST()-next field "list"
+ *
+ * This version of fast-ipsec source code  uses rawcb_list as the head,
+ *  and (to avoid namespace collisions) uses rcb_list as the "next" field.
+ */
+#ifdef __FreeBSD__
+#define rcb_list list
+#endif /* __FreeBSD__ */
+#ifdef __NetBSD__
+#define rawcb_list rawcb
+#endif	/* __NetBSD__ */
+
+
+/*
+ * 10. List of all known network interfaces.
+ * FreeBSD has listhead in_ifaddread, with ia_link as link.
+ * NetBSD has listhead in_ifaddr, with ia_list as link.
+ * No name-clahses, so just #define the appropriate names on NetBSD.
+ * NB: Is it worth introducing iterator (find-first-list/find-next-list)
+ * functions or macros to encapsulate these?
+ */
+#ifdef __FreeBSD__
+/* nothing to do for raw interface list */
+#endif	/* FreeBSD */
+#ifdef __NetBSD__
+/* For now, use FreeBSD-compatible names for raw interface list. */
+#define in_ifaddrhead in_ifaddr
+#define ia_link ia_list
+#endif	/* __NetBSD__ */
+
+
+
+
+/*
+ * Differences that we don't attempt to hide:
+ *
+ * A. Initialization code.  This  is the largest difference of all.
+ *
+ *   FreeBSD uses compile/link-time perl hackery to generate special 
+ * .o files  with linker sections  that give the moral equivalent of
+ * C++ file-level-object constructors. NetBSD has no such facility.
+ *
+ * Either we implement it (ideally, in a way that can emulate
+ * FreeBSD's SYSINIT() macros), or we must take other means
+ * to have the per-file init functions called at some appropriate time.
+ *
+ * In the absence of SYSINIT(), all the file-level init functions
+ * now have "extern" linkage. There is a new fast-ipsec init()
+ * function which calls each of the per-file in an appropriate order. 
+ * init_main will arrange to call the fast-ipsec init function
+ * after the crypto framework has registered its transforms (including
+ * any autoconfigured hardware crypto  accelerators) but before
+ * initializing the network stack to send or receive  packet.
+ *
+ * B. Protosw() differences. 
+ * CSRG-style BSD TCP/IP uses a generic protocol-dispatch-function
+ * where the specific request is identified by an enum argument.
+ * FreeBSD replaced that with an array of request-specific
+ * function pointers.
+ *
+ * These differences affect the handlers for key-protocol user requests
+ * so pervasively that I gave up on the fast-ipsec code, and re-worked the
+ * NetBSD KAME code to match the (relative few) API differences
+ * between NetBSD and FreeBSD's KAME netkey, and Fast-IPsec netkey.
+ *
+ * C. Timeout() versus callout(9):
+ * The FreeBSD 4.x netipsec/ code still uses timeout().
+ * FreeBSD 4.7 has callout(9), so I just replaced 
+ * timeout_*() with the nearest callout_*() equivalents,
+ * and added a callout handle to the ipsec context.
+ *
+ * D. SPL name differences.
+ * FreeBSD splnet() equates directly to NetBSD's splsoftnet();
+ * FreeBSD uses splimp() where (for networking) NetBSD would use splnet().
+ */
+#endif /* NETIPSEC_OSDEP_H */