ip_encap.c

来自「eCos操作系统源码」· C语言 代码 · 共 1,059 行 · 第 1/2 页

		if (!rnh->rnh_addaddr((caddr_t)ep->addrpack,
		    (caddr_t)ep->maskpack, rnh, ep->nodes)) {
			error = EEXIST;
			goto fail;
		}
	}
#endif
	return error;

#ifdef USE_RADIX
 fail:
	LIST_REMOVE(ep, chain);
	return error;
#endif
}

static int
encap_remove(ep)
	struct encaptab *ep;
{
#ifdef USE_RADIX
	struct radix_node_head *rnh = encap_rnh(ep->af);
#endif
	int error = 0;

	LIST_REMOVE(ep, chain);
#ifdef USE_RADIX
	if (!ep->func && rnh) {
		if (!rnh->rnh_deladdr((caddr_t)ep->addrpack,
		    (caddr_t)ep->maskpack, rnh))
			error = ESRCH;
	}
#endif
	return error;
}

static int
encap_afcheck(af, sp, dp)
	int af;
	const struct sockaddr *sp;
	const struct sockaddr *dp;
{
	if (sp && dp) {
		if (sp->sa_len != dp->sa_len)
			return EINVAL;
		if (af != sp->sa_family || af != dp->sa_family)
			return EINVAL;
	} else if (!sp && !dp)
		;
	else
		return EINVAL;

	switch (af) {
	case AF_INET:
		if (sp && sp->sa_len != sizeof(struct sockaddr_in))
			return EINVAL;
		if (dp && dp->sa_len != sizeof(struct sockaddr_in))
			return EINVAL;
		break;
#ifdef INET6
	case AF_INET6:
		if (sp && sp->sa_len != sizeof(struct sockaddr_in6))
			return EINVAL;
		if (dp && dp->sa_len != sizeof(struct sockaddr_in6))
			return EINVAL;
		break;
#endif
	default:
		return EAFNOSUPPORT;
	}

	return 0;
}

/*
 * sp (src ptr) is always my side, and dp (dst ptr) is always remote side.
 * length of mask (sm and dm) is assumed to be same as sp/dp.
 * Return value will be necessary as input (cookie) for encap_detach().
 */
const struct encaptab *
encap_attach(af, proto, sp, sm, dp, dm, psw, arg)
	int af;
	int proto;
	const struct sockaddr *sp, *sm;
	const struct sockaddr *dp, *dm;
	const struct protosw *psw;
	void *arg;
{
	struct encaptab *ep;
	int error;
	int s;
	size_t l;
	struct pack4 *pack4;
#ifdef INET6
	struct pack6 *pack6;
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__)
	s = splsoftnet();
#else
	s = splnet();
#endif
	/* sanity check on args */
	error = encap_afcheck(af, sp, dp);
	if (error)
		goto fail;

	/* check if anyone have already attached with exactly same config */
	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
		if (ep->af != af)
			continue;
		if (ep->proto != proto)
			continue;
		if (ep->func)
			continue;
#ifdef DIAGNOSTIC
		if (!ep->src || !ep->dst || !ep->srcmask || !ep->dstmask)
			panic("null pointers in encaptab");
#endif
		if (ep->src->sa_len != sp->sa_len ||
		    bcmp(ep->src, sp, sp->sa_len) != 0 ||
		    bcmp(ep->srcmask, sm, sp->sa_len) != 0)
			continue;
		if (ep->dst->sa_len != dp->sa_len ||
		    bcmp(ep->dst, dp, dp->sa_len) != 0 ||
		    bcmp(ep->dstmask, dm, dp->sa_len) != 0)
			continue;

		error = EEXIST;
		goto fail;
	}

	switch (af) {
	case AF_INET:
		l = sizeof(*pack4);
		break;
#ifdef INET6
	case AF_INET6:
		l = sizeof(*pack6);
		break;
#endif
	default:
		goto fail;
	}

#ifdef DIAGNOSTIC
	/* if l exceeds the value sa_len can possibly express, it's wrong. */
	if (l > (1 << (8 * sizeof(ep->addrpack->sa_len)))) {
		error = EINVAL;
		goto fail;
	}
#endif

	ep = malloc(sizeof(*ep), M_NETADDR, M_NOWAIT);	/* M_NETADDR ok? */
	if (ep == NULL) {
		error = ENOBUFS;
		goto fail;
	}
	bzero(ep, sizeof(*ep));
	ep->addrpack = malloc(l, M_NETADDR, M_NOWAIT);
	if (ep->addrpack == NULL) {
		error = ENOBUFS;
		goto gc;
	}
	ep->maskpack = malloc(l, M_NETADDR, M_NOWAIT);
	if (ep->maskpack == NULL) {
		error = ENOBUFS;
		goto gc;
	}

	ep->af = af;
	ep->proto = proto;
	ep->addrpack->sa_len = l & 0xff;
	ep->maskpack->sa_len = l & 0xff;
	switch (af) {
	case AF_INET:
		pack4 = (struct pack4 *)ep->addrpack;
		ep->src = (struct sockaddr *)&pack4->mine;
		ep->dst = (struct sockaddr *)&pack4->yours;
		pack4 = (struct pack4 *)ep->maskpack;
		ep->srcmask = (struct sockaddr *)&pack4->mine;
		ep->dstmask = (struct sockaddr *)&pack4->yours;
		break;
#ifdef INET6
	case AF_INET6:
		pack6 = (struct pack6 *)ep->addrpack;
		ep->src = (struct sockaddr *)&pack6->mine;
		ep->dst = (struct sockaddr *)&pack6->yours;
		pack6 = (struct pack6 *)ep->maskpack;
		ep->srcmask = (struct sockaddr *)&pack6->mine;
		ep->dstmask = (struct sockaddr *)&pack6->yours;
		break;
#endif
	}

	bcopy(sp, ep->src, sp->sa_len);
	bcopy(sm, ep->srcmask, sp->sa_len);
	bcopy(dp, ep->dst, dp->sa_len);
	bcopy(dm, ep->dstmask, dp->sa_len);
	ep->psw = psw;
	ep->arg = arg;

	error = encap_add(ep);
	if (error)
		goto gc;

	error = 0;
	splx(s);
	return ep;

gc:
	if (ep->addrpack)
		free(ep->addrpack, M_NETADDR);
	if (ep->maskpack)
		free(ep->maskpack, M_NETADDR);
	if (ep)
		free(ep, M_NETADDR);
fail:
	splx(s);
	return NULL;
}

const struct encaptab *
encap_attach_func(af, proto, func, psw, arg)
	int af;
	int proto;
	int (*func) __P((const struct mbuf *, int, int, void *));
	const struct protosw *psw;
	void *arg;
{
	struct encaptab *ep;
	int error;
	int s;

#if defined(__NetBSD__) || defined(__OpenBSD__)
	s = splsoftnet();
#else
	s = splnet();
#endif
	/* sanity check on args */
	if (!func) {
		error = EINVAL;
		goto fail;
	}

	error = encap_afcheck(af, NULL, NULL);
	if (error)
		goto fail;

	ep = malloc(sizeof(*ep), M_NETADDR, M_NOWAIT);	/*XXX*/
	if (ep == NULL) {
		error = ENOBUFS;
		goto fail;
	}
	bzero(ep, sizeof(*ep));

	ep->af = af;
	ep->proto = proto;
	ep->func = func;
	ep->psw = psw;
	ep->arg = arg;

	error = encap_add(ep);
	if (error)
		goto fail;

	error = 0;
	splx(s);
	return ep;

fail:
	splx(s);
	return NULL;
}

/* XXX encap4_ctlinput() is necessary if we set DF=1 on outer IPv4 header */

#ifdef INET6
#if defined(HAVE_NRL_INPCB) || (defined(__FreeBSD__) && __FreeBSD__ >= 3)
#undef in6_rtchange
#define in6_rtchange	in_rtchange
#define in6pcb		inpcb
#endif

void
encap6_ctlinput(cmd, sa, d0)
	int cmd;
	struct sockaddr *sa;
	void *d0;
{
	void *d = d0;
	struct ip6_hdr *ip6;
	struct mbuf *m;
	int off;
	struct ip6ctlparam *ip6cp = NULL;
	const struct sockaddr_in6 *sa6_src = NULL;
	void *cmdarg;
	int nxt;
	struct encaptab *ep;
	const struct ip6protosw *psw;

	if (sa->sa_family != AF_INET6 ||
	    sa->sa_len != sizeof(struct sockaddr_in6))
		return;

	if ((unsigned)cmd >= PRC_NCMDS)
		return;
	if (cmd == PRC_HOSTDEAD)
		d = NULL;
#if defined(__NetBSD__) || defined(__OpenBSD__)
	else if (cmd == PRC_MSGSIZE)
		; /* special code is present, see below */
#endif
	else if (inet6ctlerrmap[cmd] == 0)
		return;

	/* if the parameter is from icmp6, decode it. */
	if (d != NULL) {
		ip6cp = (struct ip6ctlparam *)d;
		m = ip6cp->ip6c_m;
		ip6 = ip6cp->ip6c_ip6;
		off = ip6cp->ip6c_off;
		cmdarg = ip6cp->ip6c_cmdarg;
		sa6_src = ip6cp->ip6c_src;
		nxt = ip6cp->ip6c_nxt;
	} else {
		m = NULL;
		ip6 = NULL;
		cmdarg = NULL;
		sa6_src = &sa6_any;
		nxt = -1;
	}

#if defined(__NetBSD__) || defined(__OpenBSD__)
	if (ip6 && cmd == PRC_MSGSIZE) {
		int valid = 0;
		struct encaptab *match;

		/*
		 * Check to see if we have a valid encap configuration.
		 */
		match = encap6_lookup(m, off, nxt, OUTBOUND);

		if (match)
			valid++;

		/*
		 * Depending on the value of "valid" and routing table
		 * size (mtudisc_{hi,lo}wat), we will:
		 * - recalcurate the new MTU and create the
		 *   corresponding routing entry, or
		 * - ignore the MTU change notification.
		 */
		icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
	}
#endif

	/* inform all listeners */
	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
		if (ep->af != AF_INET6)
			continue;
		if (ep->proto >= 0 && ep->proto != nxt)
			continue;

		/* should optimize by looking at address pairs */

		/* XXX need to pass ep->arg or ep itself to listeners */
		psw = (const struct ip6protosw *)ep->psw;
		if (psw && psw->pr_ctlinput)
			(*psw->pr_ctlinput)(cmd, sa, d);
	}

	rip6_ctlinput(cmd, sa, d0);
}
#endif

int
encap_detach(cookie)
	const struct encaptab *cookie;
{
	const struct encaptab *ep = cookie;
	struct encaptab *p;
	int error;

	for (p = LIST_FIRST(&encaptab); p; p = LIST_NEXT(p, chain)) {
		if (p == ep) {
			error = encap_remove(p);
			if (error)
				return error;
			if (!ep->func) {
				free(p->addrpack, M_NETADDR);
				free(p->maskpack, M_NETADDR);
			}
			free(p, M_NETADDR);	/*XXX*/
			return 0;
		}
	}

	return ENOENT;
}

#ifdef USE_RADIX
static struct radix_node_head *
encap_rnh(af)
	int af;
{

	switch (af) {
	case AF_INET:
		return encap_head[0];
#ifdef INET6
	case AF_INET6:
		return encap_head[1];
#endif
	default:
		return NULL;
	}
}

static int
mask_matchlen(sa)
	const struct sockaddr *sa;
{
	const char *p, *ep;
	int l;

	p = (const char *)sa;
	ep = p + sa->sa_len;
	p += 2;	/* sa_len + sa_family */

	l = 0;
	while (p < ep) {
		l += (*p ? 8 : 0);	/* estimate */
		p++;
	}
	return l;
}
#endif

#ifndef USE_RADIX
static int
mask_match(ep, sp, dp)
	const struct encaptab *ep;
	const struct sockaddr *sp;
	const struct sockaddr *dp;
{
	struct sockaddr_storage s;
	struct sockaddr_storage d;
	int i;
	const u_int8_t *p, *q;
	u_int8_t *r;
	int matchlen;

#ifdef DIAGNOSTIC
	if (ep->func)
		panic("wrong encaptab passed to mask_match");
#endif
	if (sp->sa_len > sizeof(s) || dp->sa_len > sizeof(d))
		return 0;
	if (sp->sa_family != ep->af || dp->sa_family != ep->af)
		return 0;
	if (sp->sa_len != ep->src->sa_len || dp->sa_len != ep->dst->sa_len)
		return 0;

	matchlen = 0;

	p = (const u_int8_t *)sp;
	q = (const u_int8_t *)ep->srcmask;
	r = (u_int8_t *)&s;
	for (i = 0 ; i < sp->sa_len; i++) {
		r[i] = p[i] & q[i];
		/* XXX estimate */
		matchlen += (q[i] ? 8 : 0);
	}

	p = (const u_int8_t *)dp;
	q = (const u_int8_t *)ep->dstmask;
	r = (u_int8_t *)&d;
	for (i = 0 ; i < dp->sa_len; i++) {
		r[i] = p[i] & q[i];
		/* XXX rough estimate */
		matchlen += (q[i] ? 8 : 0);
	}

	/* need to overwrite len/family portion as we don't compare them */
	s.ss_len = sp->sa_len;
	s.ss_family = sp->sa_family;
	d.ss_len = dp->sa_len;
	d.ss_family = dp->sa_family;

	if (bcmp(&s, ep->src, ep->src->sa_len) == 0 &&
	    bcmp(&d, ep->dst, ep->dst->sa_len) == 0) {
		return matchlen;
	} else
		return 0;
}
#endif

static void
encap_fillarg(m, ep)
	struct mbuf *m;
	const struct encaptab *ep;
{
	struct mbuf *n;

	n = m_aux_add(m, AF_INET, IPPROTO_IPV4);
	if (n) {
		*mtod(n, void **) = ep->arg;
		n->m_len = sizeof(void *);
	}
}

void *
encap_getarg(m)
	struct mbuf *m;
{
	void *p;
	struct mbuf *n;

	p = NULL;
	n = m_aux_find(m, AF_INET, IPPROTO_IPV4);
	if (n) {
		if (n->m_len == sizeof(void *))
			p = *mtod(n, void **);
		m_aux_delete(m, n);
	}
	return p;
}