diff options
Diffstat (limited to 'slirp/src/ip_output.c')
| -rw-r--r-- | slirp/src/ip_output.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/slirp/src/ip_output.c b/slirp/src/ip_output.c new file mode 100644 index 0000000000..f6ec141df5 --- /dev/null +++ b/slirp/src/ip_output.c @@ -0,0 +1,172 @@ +/* + * 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 = %p", so); + DEBUG_ARG("m0 = %p", 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 ((uint16_t)ip->ip_len <= IF_MTU) { + ip->ip_len = htons((uint16_t)ip->ip_len); + ip->ip_off = htons((uint16_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 < (uint16_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 >= (uint16_t)ip->ip_len) + len = (uint16_t)ip->ip_len - off; + else + mhip->ip_off |= IP_MF; + mhip->ip_len = htons((uint16_t)(len + mhlen)); + + if (m_copy(m, m0, off, len) < 0) { + error = -1; + goto sendorfree; + } + + mhip->ip_off = htons((uint16_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 - (uint16_t)ip->ip_len); + ip->ip_len = htons((uint16_t)m->m_len); + ip->ip_off = htons((uint16_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_free(m); + } + } + +done: + return (error); + +bad: + m_free(m0); + goto done; +} |