ip6_output.c

来自「eCos操作系统源码」· C语言 代码 · 共 2,527 行 · 第 1/5 页

#endif
			error = nd6_output(ifp, origifp, m, dst, rt);
		} else
			m_freem(m);
	}

	if (error == 0)
		ip6stat.ip6s_fragmented++;

done:
	if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
		RTFREE(ro->ro_rt);
	} else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
		RTFREE(ro_pmtu->ro_rt);
	}

#if defined(IPSEC) && !defined(__OpenBSD__)
	if (sp != NULL)
		key_freesp(sp);
#endif /* IPSEC */

#ifdef MIP6
	mip6_destopt_discard(&mip6opt);
#endif /* MIP6 */

	return(error);

freehdrs:
#ifdef MIP6
	mip6_destopt_discard(&mip6opt);
#endif /* MIP6 */
	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
	m_freem(exthdrs.ip6e_dest1);
	m_freem(exthdrs.ip6e_rthdr);
#ifdef MIP6
	m_freem(exthdrs.ip6e_haddr);
#endif /* MIP6 */
	m_freem(exthdrs.ip6e_dest2);
	/* fall through */
bad:
	m_freem(m);
	goto done;
}

static int
ip6_copyexthdr(mp, hdr, hlen)
	struct mbuf **mp;
	caddr_t hdr;
	int hlen;
{
	struct mbuf *m;

	if (hlen > MCLBYTES)
		return(ENOBUFS); /* XXX */

	MGET(m, M_DONTWAIT, MT_DATA);
	if (!m)
		return(ENOBUFS);

	if (hlen > MLEN) {
		MCLGET(m, M_DONTWAIT);
		if ((m->m_flags & M_EXT) == 0) {
			m_free(m);
			return(ENOBUFS);
		}
	}
	m->m_len = hlen;
	if (hdr)
		bcopy(hdr, mtod(m, caddr_t), hlen);

	*mp = m;
	return(0);
}

/*
 * Insert jumbo payload option.
 */
static int
ip6_insert_jumboopt(exthdrs, plen)
	struct ip6_exthdrs *exthdrs;
	u_int32_t plen;
{
	struct mbuf *mopt;
	u_char *optbuf;
	u_int32_t v;

#define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */

	/*
	 * If there is no hop-by-hop options header, allocate new one.
	 * If there is one but it doesn't have enough space to store the
	 * jumbo payload option, allocate a cluster to store the whole options.
	 * Otherwise, use it to store the options.
	 */
	if (exthdrs->ip6e_hbh == 0) {
		MGET(mopt, M_DONTWAIT, MT_DATA);
		if (mopt == 0)
			return(ENOBUFS);
		mopt->m_len = JUMBOOPTLEN;
		optbuf = mtod(mopt, u_char *);
		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
		exthdrs->ip6e_hbh = mopt;
	} else {
		struct ip6_hbh *hbh;

		mopt = exthdrs->ip6e_hbh;
		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
			/*
			 * XXX assumption:
			 * - exthdrs->ip6e_hbh is not referenced from places
			 *   other than exthdrs.
			 * - exthdrs->ip6e_hbh is not an mbuf chain.
			 */
			int oldoptlen = mopt->m_len;
			struct mbuf *n;

			/*
			 * XXX: give up if the whole (new) hbh header does
			 * not fit even in an mbuf cluster.
			 */
			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
				return(ENOBUFS);

			/*
			 * As a consequence, we must always prepare a cluster
			 * at this point.
			 */
			MGET(n, M_DONTWAIT, MT_DATA);
			if (n) {
				MCLGET(n, M_DONTWAIT);
				if ((n->m_flags & M_EXT) == 0) {
					m_freem(n);
					n = NULL;
				}
			}
			if (!n)
				return(ENOBUFS);
			n->m_len = oldoptlen + JUMBOOPTLEN;
			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
			      oldoptlen);
			optbuf = mtod(n, caddr_t) + oldoptlen;
			m_freem(mopt);
			mopt = exthdrs->ip6e_hbh = n;
		} else {
			optbuf = mtod(mopt, u_char *) + mopt->m_len;
			mopt->m_len += JUMBOOPTLEN;
		}
		optbuf[0] = IP6OPT_PADN;
		optbuf[1] = 1;

		/*
		 * Adjust the header length according to the pad and
		 * the jumbo payload option.
		 */
		hbh = mtod(mopt, struct ip6_hbh *);
		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
	}

	/* fill in the option. */
	optbuf[2] = IP6OPT_JUMBO;
	optbuf[3] = 4;
	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
	bcopy(&v, &optbuf[4], sizeof(u_int32_t));

	/* finally, adjust the packet header length */
	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;

	return(0);
#undef JUMBOOPTLEN
}

/*
 * Insert fragment header and copy unfragmentable header portions.
 */
static int
ip6_insertfraghdr(m0, m, hlen, frghdrp)
	struct mbuf *m0, *m;
	int hlen;
	struct ip6_frag **frghdrp;
{
	struct mbuf *n, *mlast;

	if (hlen > sizeof(struct ip6_hdr)) {
		n = m_copym(m0, sizeof(struct ip6_hdr),
			    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
		if (n == 0)
			return(ENOBUFS);
		m->m_next = n;
	} else
		n = m;

	/* Search for the last mbuf of unfragmentable part. */
	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
		;

	if ((mlast->m_flags & M_EXT) == 0 &&
	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
		/* use the trailing space of the last mbuf for the fragment hdr */
		*frghdrp =
			(struct ip6_frag *)(mtod(mlast, caddr_t) + mlast->m_len);
		mlast->m_len += sizeof(struct ip6_frag);
		m->m_pkthdr.len += sizeof(struct ip6_frag);
	} else {
		/* allocate a new mbuf for the fragment header */
		struct mbuf *mfrg;

		MGET(mfrg, M_DONTWAIT, MT_DATA);
		if (mfrg == 0)
			return(ENOBUFS);
		mfrg->m_len = sizeof(struct ip6_frag);
		*frghdrp = mtod(mfrg, struct ip6_frag *);
		mlast->m_next = mfrg;
	}

	return(0);
}

static int
ip6_getpmtu(ro_pmtu, ro, ifp, dst, mtup)
#ifdef NEW_STRUCT_ROUTE
	struct route *ro_pmtu, *ro;
#else
	struct route_in6 *ro_pmtu, *ro;
#endif
	struct ifnet *ifp;
	struct in6_addr *dst;	/* XXX: should be sockaddr_in6 */
	u_long *mtup;
{
	u_int32_t mtu = 0;
	int error = 0;

	if (ro_pmtu != ro) {
		/* The first hop and the final destination may differ. */
		struct sockaddr_in6 *sa6_dst =
			(struct sockaddr_in6 *)&ro_pmtu->ro_dst;
		if (ro_pmtu->ro_rt && ((ro_pmtu->ro_rt->rt_flags & RTF_UP)
				       == 0 ||
				       !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr,
							   dst))) {
			RTFREE(ro_pmtu->ro_rt);
			ro_pmtu->ro_rt = (struct rtentry *)NULL;
		}
		if (ro_pmtu->ro_rt == NULL) {
			bzero(sa6_dst, sizeof(*sa6_dst));
			sa6_dst->sin6_family = AF_INET6;
			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
			sa6_dst->sin6_addr = *dst;

#ifdef __bsdi__			/* bsdi needs rtcalloc to clone a route. */
			rtcalloc((struct route *)ro_pmtu);
#else
			rtalloc((struct route *)ro_pmtu);
#endif
		}
	}
	if (ro_pmtu->ro_rt) {
		u_int32_t ifmtu;

		if (ifp == NULL)
			ifp = ro_pmtu->ro_rt->rt_ifp;
		ifmtu = nd_ifinfo[ifp->if_index].linkmtu;
		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
		if (mtu > ifmtu || mtu == 0) {
			/*
			 * The MTU on the route is larger than the MTU on
			 * the interface!  This shouldn't happen, unless the
			 * MTU of the interface has been changed after the
			 * interface was brought up.  Change the MTU in the
			 * route to match the interface MTU (as long as the
			 * field isn't locked).
			 *
			 * if MTU on the route is 0, we need to fix the MTU.
			 * this case happens with path MTU discovery timeouts.
			 */
			 mtu = ifmtu;
			 if ((ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
				 ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu; /* XXX */
		}
	} else if (ifp) {
		mtu = nd_ifinfo[ifp->if_index].linkmtu;
	} else
		error = EHOSTUNREACH; /* XXX */

	*mtup = mtu;
	return(error);
}

/*
 * IP6 socket option processing.
 */
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
int
ip6_ctloutput(so, sopt)
	struct socket *so;
	struct sockopt *sopt;
#else
int
ip6_ctloutput(op, so, level, optname, mp)
	int op;
	struct socket *so;
	int level, optname;
	struct mbuf **mp;
#endif
{
	int privileged, optdatalen;
	void *optdata;
	struct ip6_recvpktopts *rcvopts;
#if defined(IPSEC) && defined(__OpenBSD__)
	struct proc *p = curproc; /* XXX */
	struct tdb *tdb;
	struct tdb_ident *tdbip, tdbi;
	int s;
#endif
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
	struct inpcb *in6p = sotoinpcb(so);
	int error, optval;
	int level, op, optname;
	int optlen;
	struct proc *p;

	if (!sopt) {
		panic("ip6_ctloutput: arg soopt is NULL");
	}
        level = sopt->sopt_level;
        op = sopt->sopt_dir;
        optname = sopt->sopt_name;
        optlen = sopt->sopt_valsize;
        p = sopt->sopt_p;
#else
#ifdef HAVE_NRL_INPCB
	struct inpcb *inp = sotoinpcb(so);
#define in6p inp
#else  /* !NRL */
	struct in6pcb *in6p = sotoin6pcb(so);
#endif /* HAVE_NRL_INPCB */
	struct mbuf *m = *mp;
	int error, optval;
	int optlen;
#if defined(__NetBSD__) || (defined(__FreeBSD__) && __FreeBSD__ >= 3)
	struct proc *p = curproc;	/* XXX */
#endif

	optlen = m ? m->m_len : 0;
#endif /* FreeBSD >= 3 */
	error = optval = 0;
        privileged = 1;

	rcvopts = in6p->in6p_inputopts;

	if (level == IPPROTO_IPV6) {
		switch (op) {

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
		case SOPT_SET:
#else
		case PRCO_SETOPT:
#endif
			switch (optname) {
			case IPV6_2292PKTOPTIONS:
#ifdef IPV6_PKTOPTIONS
			case IPV6_PKTOPTIONS:
#endif
			{
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
				struct mbuf *m;

				error = soopt_getm(sopt, &m); /* XXX */
				if (error)
					break;
				error = soopt_mcopyin(sopt, m); /* XXX */
				if (error)
					break;
				error = ip6_pcbopts(&in6p->in6p_outputopts,
						    m, so, sopt);
				m_freem(m); /* XXX */
#else
				error = ip6_pcbopts(&in6p->in6p_outputopts,
						    m, so);
#endif /* FreeBSD >= 3 */
				break;
			}

			/*
			 * Use of some Hop-by-Hop options or some
			 * Destination options, might require special
			 * privilege.  That is, normal applications
			 * (without special privilege) might be forbidden
			 * from setting certain options in outgoing packets,
			 * and might never see certain options in received
			 * packets. [RFC 2292 Section 6]
			 * KAME specific note:
			 *  KAME prevents non-privileged users from sending or
			 *  receiving ANY hbh/dst options in order to avoid
			 *  overhead of parsing options in the kernel.
			 */
			case IPV6_RECVHOPOPTS:
			case IPV6_RECVDSTOPTS:
			case IPV6_RECVRTHDRDSTOPTS:
				/* fall through */
			case IPV6_UNICAST_HOPS:
			case IPV6_HOPLIMIT:
			case IPV6_FAITH:

			case IPV6_RECVPKTINFO:
			case IPV6_RECVHOPLIMIT:
			case IPV6_RECVRTHDR:
			case IPV6_RECVPATHMTU:
			case IPV6_RECVTCLASS:
			case IPV6_V6ONLY:
			case IPV6_AUTOFLOWLABEL:
				if (optlen != sizeof(int)) {
					error = EINVAL;
					break;
				}
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
				error = sooptcopyin(sopt, &optval,
					sizeof optval, sizeof optval);
				if (error)
					break;
#else
				optval = *mtod(m, int *);
#endif
				switch (optname) {

				case IPV6_UNICAST_HOPS:
					if (optval < -1 || optval >= 256)
						error = EINVAL;
					else {
						/* -1 = kernel default */
						in6p->in6p_hops = optval;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
						if ((in6p->in6p_vflag &
						     INP_IPV4) != 0)
							in6p->inp_ip_ttl = optval;
#endif
					}
					break;
#define OPTSET(bit) \
do { \
	if (optval) \
		in6p->in6p_flags |= (bit); \
	else \
		in6p->in6p_flags &= ~(bit); \
} while (0)
#define OPTSET2292(bit) \
do { \
	in6p->in6p_flags |= IN6P_RFC2292; \
	if (optval) \
		in6p->in6p_flags |= (bit); \
	else \
		in6p->in6p_flags &= ~(bit); \
} while (0)
#define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)

				case IPV6_RECVPKTINFO:
					/* cannot mix with RFC2292 */
					if (OPTBIT(IN6P_RFC2292)) {
						error = EINVAL;
						break;
					}
					OPTSET(IN6P_PKTINFO);
					if (OPTBIT(IN6P_PKTINFO) == 0)
						ip6_reset_rcvopt(rcvopts, IPV6_RECVPKTINFO);
					break;

				case IPV6_HOPLIMIT:
				{
					struct ip6_pktopts **optp;

					/* cannot mix with RFC2292 */
					if (OPTBIT(IN6P_RFC2292)) {
						error = EINVAL;
						break;
					}
					optp = &in6p->in6p_outputopts;
					error = ip6_pcbopt(IPV6_HOPLIMIT,
							   (u_char *)&optval,
							   sizeof(optval),
							   optp,
							   privileged);
					break;
				}

				case IPV6_RECVHOPLIMIT:
					/* cannot mix with RFC2292 */
					if (OPTBIT(IN6P_RFC2292)) {
						error = EINVAL;
						break;
					}
					OPTSET(IN6P_HOPLIMIT);
					if (OPTBIT(IN6P_HOPLIMIT) == 0)
						ip6_reset_rcvopt(rcvopts, IPV6_RECVHOPLIMIT);
					break;

				case IPV6_RECVHOPOPTS:
					/* cannot mix with RFC2292 */
					if (OPTBIT(IN6P_RFC2292)) {
						error = EINVAL;
						break;
					}
					OPTSET(IN6P_HOPOPTS);
					if (OPTBIT(IN6P_HOPOPTS) == 0)
						ip6_reset_rcvopt(rcvopts, IPV6_RECVHOPOPTS);
					break;

				case IPV6_RECVDSTOPTS: