clnp_output.c

早期freebsd实现

					IFDEBUG(D_OUTPUT)
						printf("clnp_output: no mbufs to allocate to cache\n");
					ENDDEBUG
					flags  |= CLNP_NOCACHE;
					clcp = &clc;
				} else {
					clcp = mtod(isop->isop_clnpcache, struct clnp_cache *);
				}
			} else {
				/*
				 *	A clnpcache mbuf exists. If the clc_hdr is not null,
				 *	we must free it, as a new one is about to be created.
				 */
				clcp = mtod(isop->isop_clnpcache, struct clnp_cache *);
				if (clcp->clc_hdr != NULL) {
					/*
					 *	The clc_hdr is not null but a clnpcache mbuf exists.
					 *	This means that there was a cache, but the existing
					 *	copy of the hdr is no longer valid. Free it now
					 *	before we lose the pointer to it.
					 */
					IFDEBUG(D_OUTPUT)
						printf("clnp_output: freeing old clc_hdr 0x%x\n",
						clcp->clc_hdr);
					ENDDEBUG
					m_free(clcp->clc_hdr);
					IFDEBUG(D_OUTPUT)
						printf("clnp_output: freed old clc_hdr (done)\n");
					ENDDEBUG
				}
			}
		}
		IFDEBUG(D_OUTPUT)
			printf("clnp_output: NEW clcp x%x\n",clcp);
		ENDDEBUG
		bzero((caddr_t)clcp, sizeof(struct clnp_cache));

		if (isop->isop_optindex)
			oidx = mtod(isop->isop_optindex, struct clnp_optidx *);

		/*
		 *	Don't allow packets with security, quality of service,
		 *	priority, or error report options to be sent.
		 */
		if ((isop->isop_options) && (oidx)) {
			if ((oidx->cni_securep) ||
				(oidx->cni_priorp) ||
				(oidx->cni_qos_formatp) ||
				(oidx->cni_er_reason != ER_INVALREAS)) {
				IFDEBUG(D_OUTPUT)
					printf("clnp_output: pkt dropped - option unsupported\n");
				ENDDEBUG
				m_freem(m0);
				return(EINVAL);
			}
		}

		/*
		 *	Don't allow any invalid flags to be set
		 */
		if ((flags & (CLNP_VFLAGS)) != flags) {
			IFDEBUG(D_OUTPUT)
				printf("clnp_output: packet dropped - flags unsupported\n");
			ENDDEBUG
			INCSTAT(cns_odropped);
			m_freem(m0);
			return(EINVAL);
		}

		/*
		 *	Don't allow funny lengths on dst; src may be zero in which
		 *	case we insert the source address based upon the interface
		 */
		if ((src->isoa_len > sizeof(struct iso_addr)) || 
			(dst->isoa_len == 0) ||
			(dst->isoa_len > sizeof(struct iso_addr))) {
			m_freem(m0);
			INCSTAT(cns_odropped);
			return(ENAMETOOLONG);
		}

		/*
		 *	Grab mbuf to contain header
		 */
		MGETHDR(m, M_DONTWAIT, MT_HEADER);
		if (m == 0) {
			m_freem(m0);
			INCSTAT(cns_odropped);
			return(ENOBUFS);
		}
		INCSTAT(cns_sent);
		m->m_next = m0;
		clnp = mtod(m, struct clnp_fixed *);
		clcp->clc_segoff = 0;

		/*
		 *	Fill in all of fixed hdr except lengths and checksum
		 */
		if (flags & CLNP_SEND_RAW) {
			*clnp = raw_template;
		} else if (flags & CLNP_ECHO) {
			*clnp = echo_template;
		} else if (flags & CLNP_ECHOR) {
			*clnp = echor_template;
		} else {
			*clnp = dt_template;
		}
		if (flags & CLNP_NO_SEG)
			clnp->cnf_type &= ~CNF_SEG_OK;
		if (flags & CLNP_NO_ER)
			clnp->cnf_type &= ~CNF_ERR_OK;

		/*
		 *	Route packet; special case for source rt
		 */
		if ((isop->isop_options) && CLNPSRCRT_VALID(oidx)) {
			IFDEBUG(D_OUTPUT)
				printf("clnp_output: calling clnp_srcroute\n");
			ENDDEBUG
			error = clnp_srcroute(isop->isop_options, oidx, &isop->isop_route,
				&clcp->clc_firsthop, &clcp->clc_ifa, dst);
		} else {
			IFDEBUG(D_OUTPUT)
			ENDDEBUG
			error = clnp_route(dst, &isop->isop_route, flags, 
				&clcp->clc_firsthop, &clcp->clc_ifa);
		}
		if (error || (clcp->clc_ifa == 0)) {
			IFDEBUG(D_OUTPUT)
				printf("clnp_output: route failed, errno %d\n", error);
				printf("@clcp:\n");
				dump_buf(clcp, sizeof (struct clnp_cache));
			ENDDEBUG
			goto bad;
		}
		clcp->clc_rt = isop->isop_route.ro_rt;	/* XXX */
		clcp->clc_ifp = clcp->clc_ifa->ia_ifp;  /* XXX */

		IFDEBUG(D_OUTPUT)
			printf("clnp_output: packet routed to %s\n", 
				clnp_iso_addrp(
					&((struct sockaddr_iso *)clcp->clc_firsthop)->siso_addr));
		ENDDEBUG
		
		/*
		 *	If src address is not yet specified, use address of 
		 *	interface. NOTE: this will now update the laddr field in
		 *	the isopcb. Is this desirable? RAH?
		 */
		if (src->isoa_len == 0) {
			src = &(clcp->clc_ifa->ia_addr.siso_addr);
			IFDEBUG(D_OUTPUT)
				printf("clnp_output: new src %s\n", clnp_iso_addrp(src));
			ENDDEBUG
		}

		/*
		 *	Insert the source and destination address,
		 */
		hoff = (caddr_t)clnp + sizeof(struct clnp_fixed);
		CLNP_INSERT_ADDR(hoff, *dst);
		CLNP_INSERT_ADDR(hoff, *src);

		/*
		 *	Leave room for the segment part, if segmenting is selected
		 */
		if (clnp->cnf_type & CNF_SEG_OK) {
			clcp->clc_segoff = hoff - (caddr_t)clnp;
			hoff += sizeof(struct clnp_segment);
		}

		clnp->cnf_hdr_len = m->m_len = (u_char)(hoff - (caddr_t)clnp);
		hdrlen = clnp->cnf_hdr_len;

#ifdef	DECBIT
		/*
		 *	Add the globally unique QOS (with room for congestion experienced
		 *	bit). I can safely assume that this option is not in the options
		 *	mbuf below because I checked that the option was not specified
		 *	previously
		 */
		if ((m->m_len + sizeof(qos_option)) < MLEN) {
			bcopy((caddr_t)qos_option, hoff, sizeof(qos_option));
			clnp->cnf_hdr_len += sizeof(qos_option);
			hdrlen += sizeof(qos_option);
			m->m_len += sizeof(qos_option);
		}
#endif	/* DECBIT */

		/*
		 *	If an options mbuf is present, concatenate a copy to the hdr mbuf.
		 */
		if (isop->isop_options) {
			struct mbuf *opt_copy = m_copy(isop->isop_options, 0, (int)M_COPYALL);
			if (opt_copy == NULL) {
				error = ENOBUFS;
				goto bad;
			}
			/* Link in place */
			opt_copy->m_next = m->m_next;
			m->m_next = opt_copy;

			/* update size of header */
			clnp->cnf_hdr_len += opt_copy->m_len;
			hdrlen += opt_copy->m_len;
		}

		if (hdrlen > CLNP_HDR_MAX) {
			error = EMSGSIZE;
			goto bad;
		}

		/*
		 *	Now set up the cache entry in the pcb
		 */
		if ((flags & CLNP_NOCACHE) == 0) {
			if (clcp->clc_hdr = m_copy(m, 0, (int)clnp->cnf_hdr_len)) {
				clcp->clc_dst  = *dst;
				clcp->clc_flags = flags;
				clcp->clc_options = isop->isop_options;
			}
		}
	}
	/*
	 *	If small enough for interface, send directly
	 *	Fill in segmentation part of hdr if using the full protocol
	 */
	total_len = clnp->cnf_hdr_len + datalen;
	if (clnp->cnf_type & CNF_SEG_OK) {
		struct clnp_segment	seg_part;		/* segment part of hdr */
		seg_part.cng_id = htons(clnp_id++);
		seg_part.cng_off = htons(0);
		seg_part.cng_tot_len = htons(total_len);
		(void) bcopy((caddr_t)&seg_part, (caddr_t) clnp + clcp->clc_segoff, 
			sizeof(seg_part));
	}
	if (total_len <= SN_MTU(clcp->clc_ifp, clcp->clc_rt)) {
		HTOC(clnp->cnf_seglen_msb, clnp->cnf_seglen_lsb, total_len);
		m->m_pkthdr.len = total_len;
		/*
		 *	Compute clnp checksum (on header only)
		 */
		if (flags & CLNP_NO_CKSUM) {
			HTOC(clnp->cnf_cksum_msb, clnp->cnf_cksum_lsb, 0);
		} else {
			iso_gen_csum(m, CLNP_CKSUM_OFF, (int)clnp->cnf_hdr_len);
		}

		IFDEBUG(D_DUMPOUT)
			struct mbuf *mdump = m;
			printf("clnp_output: sending dg:\n");
			while (mdump != NULL) {
				dump_buf(mtod(mdump, caddr_t), mdump->m_len);
				mdump = mdump->m_next;
			}
		ENDDEBUG

		error = SN_OUTPUT(clcp, m);
		goto done;
	} else {
		/*
		 * Too large for interface; fragment if possible.
		 */
		error = clnp_fragment(clcp->clc_ifp, m, clcp->clc_firsthop,
							total_len, clcp->clc_segoff, flags, clcp->clc_rt);
		goto done;
	}
bad:
	m_freem(m);
done:
	if (error) {
		clnp_stat.cns_sent--;
		clnp_stat.cns_odropped++;
	}
	return (error);
}

int clnp_ctloutput()
{
}