/* * Copyright (c) 1982, 1986, 1988, 1990, 1993 * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 * ip_output.c,v 1.9 1994/11/16 10:17:10 jkh Exp */ /* * Changes and additions relating to SLiRP are * Copyright (c) 1995 Danny Gasparovski. * * Please read the file COPYRIGHT for the * terms and conditions of the copyright. */ #include <slirp.h> /* Number of packets queued before we start sending * (to prevent allocing too many mbufs) */ #define IF_THRESH 10 /* * IP output. The packet in mbuf chain m contains a skeletal IP * header (with len, off, ttl, proto, tos, src, dst). * The mbuf chain containing the packet will be freed. * The mbuf opt, if present, will not be freed. */ int ip_output(struct socket *so, struct mbuf *m0) { Slirp *slirp = m0->slirp; register struct ip *ip; register struct mbuf *m = m0; register int hlen = sizeof(struct ip ); int len, off, error = 0; DEBUG_CALL("ip_output"); DEBUG_ARG("so = %lx", (long)so); DEBUG_ARG("m0 = %lx", (long)m0); ip = mtod(m, struct ip *); /* * Fill in IP header. */ ip->ip_v = IPVERSION; ip->ip_off &= IP_DF; ip->ip_id = htons(slirp->ip_id++); ip->ip_hl = hlen >> 2; /* * If small enough for interface, can just send directly. */ if ((u_int16_t)ip->ip_len <= IF_MTU) { ip->ip_len = htons((u_int16_t)ip->ip_len); ip->ip_off = htons((u_int16_t)ip->ip_off); ip->ip_sum = 0; ip->ip_sum = cksum(m, hlen); if_output(so, m); goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->ip_off & IP_DF) { error = -1; goto bad; } len = (IF_MTU - hlen) &~ 7; /* ip databytes per packet */ if (len < 8) { error = -1; goto bad; } { int mhlen, firstlen = len; struct mbuf **mnext = &m->m_nextpkt; /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto chain. */ m0 = m; mhlen = sizeof (struct ip); for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { register struct ip *mhip; m = m_get(slirp); if (m == NULL) { error = -1; goto sendorfree; } m->m_data += IF_MAXLINKHDR; mhip = mtod(m, struct ip *); *mhip = *ip; m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); if (ip->ip_off & IP_MF) mhip->ip_off |= IP_MF; if (off + len >= (u_int16_t)ip->ip_len) len = (u_int16_t)ip->ip_len - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_int16_t)(len + mhlen)); if (m_copy(m, m0, off, len) < 0) { error = -1; goto sendorfree; } mhip->ip_off = htons((u_int16_t)mhip->ip_off); mhip->ip_sum = 0; mhip->ip_sum = cksum(m, mhlen); *mnext = m; mnext = &m->m_nextpkt; } /* * Update first fragment by trimming what's been copied out * and updating header, then send each fragment (in order). */ m = m0; m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); ip->ip_len = htons((u_int16_t)m->m_len); ip->ip_off = htons((u_int16_t)(ip->ip_off | IP_MF)); ip->ip_sum = 0; ip->ip_sum = cksum(m, hlen); sendorfree: for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = NULL; if (error == 0) if_output(so, m); else m_freem(m); } } done: return (error); bad: m_freem(m0); goto done; }