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/* |
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* Copyright (c) 1982, 1986, 1988, 1990, 1993 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. All advertising materials mentioning features or use of this software |
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* must display the following acknowledgement: |
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* This product includes software developed by the University of |
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* California, Berkeley and its contributors. |
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* 4. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* |
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* @(#)ip_output.c 8.3 (Berkeley) 1/21/94 |
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* ip_output.c,v 1.9 1994/11/16 10:17:10 jkh Exp |
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*/ |
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|
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/* |
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* Changes and additions relating to SLiRP are |
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* Copyright (c) 1995 Danny Gasparovski. |
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* |
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* Please read the file COPYRIGHT for the |
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* terms and conditions of the copyright. |
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*/ |
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|
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#include <slirp.h> |
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|
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u_int16_t ip_id; |
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|
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/* |
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* IP output. The packet in mbuf chain m contains a skeletal IP |
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* header (with len, off, ttl, proto, tos, src, dst). |
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* The mbuf chain containing the packet will be freed. |
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* The mbuf opt, if present, will not be freed. |
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*/ |
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int |
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ip_output(so, m0) |
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struct socket *so; |
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struct mbuf *m0; |
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{ |
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register struct ip *ip; |
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register struct mbuf *m = m0; |
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register int hlen = sizeof(struct ip ); |
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int len, off, error = 0; |
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|
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DEBUG_CALL("ip_output"); |
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DEBUG_ARG("so = %lx", (long)so); |
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DEBUG_ARG("m0 = %lx", (long)m0); |
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|
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/* We do no options */ |
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/* if (opt) { |
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* m = ip_insertoptions(m, opt, &len); |
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* hlen = len; |
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* } |
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*/ |
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ip = mtod(m, struct ip *); |
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/* |
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* Fill in IP header. |
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*/ |
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ip->ip_v = IPVERSION; |
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ip->ip_off &= IP_DF; |
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ip->ip_id = htons(ip_id++); |
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ip->ip_hl = hlen >> 2; |
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ipstat.ips_localout++; |
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|
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/* |
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* Verify that we have any chance at all of being able to queue |
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* the packet or packet fragments |
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*/ |
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/* XXX Hmmm... */ |
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/* if (if_queued > if_thresh && towrite <= 0) { |
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* error = ENOBUFS; |
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* goto bad; |
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* } |
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*/ |
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|
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/* |
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* If small enough for interface, can just send directly. |
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*/ |
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if ((u_int16_t)ip->ip_len <= if_mtu) { |
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ip->ip_len = htons((u_int16_t)ip->ip_len); |
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ip->ip_off = htons((u_int16_t)ip->ip_off); |
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ip->ip_sum = 0; |
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ip->ip_sum = cksum(m, hlen); |
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|
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if_output(so, m); |
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goto done; |
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} |
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|
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/* |
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* Too large for interface; fragment if possible. |
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* Must be able to put at least 8 bytes per fragment. |
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*/ |
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if (ip->ip_off & IP_DF) { |
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error = -1; |
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ipstat.ips_cantfrag++; |
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goto bad; |
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} |
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|
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len = (if_mtu - hlen) &~ 7; /* ip databytes per packet */ |
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if (len < 8) { |
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error = -1; |
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goto bad; |
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} |
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|
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{ |
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int mhlen, firstlen = len; |
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struct mbuf **mnext = &m->m_nextpkt; |
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|
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/* |
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* Loop through length of segment after first fragment, |
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* make new header and copy data of each part and link onto chain. |
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*/ |
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m0 = m; |
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mhlen = sizeof (struct ip); |
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for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { |
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register struct ip *mhip; |
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m = m_get(); |
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if (m == 0) { |
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error = -1; |
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ipstat.ips_odropped++; |
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goto sendorfree; |
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} |
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m->m_data += if_maxlinkhdr; |
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mhip = mtod(m, struct ip *); |
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*mhip = *ip; |
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|
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/* No options */ |
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/* if (hlen > sizeof (struct ip)) { |
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* mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); |
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* mhip->ip_hl = mhlen >> 2; |
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* } |
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*/ |
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m->m_len = mhlen; |
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mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); |
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if (ip->ip_off & IP_MF) |
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mhip->ip_off |= IP_MF; |
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if (off + len >= (u_int16_t)ip->ip_len) |
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len = (u_int16_t)ip->ip_len - off; |
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else |
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mhip->ip_off |= IP_MF; |
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mhip->ip_len = htons((u_int16_t)(len + mhlen)); |
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|
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if (m_copy(m, m0, off, len) < 0) { |
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error = -1; |
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goto sendorfree; |
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} |
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|
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mhip->ip_off = htons((u_int16_t)mhip->ip_off); |
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mhip->ip_sum = 0; |
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mhip->ip_sum = cksum(m, mhlen); |
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*mnext = m; |
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mnext = &m->m_nextpkt; |
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ipstat.ips_ofragments++; |
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} |
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/* |
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* Update first fragment by trimming what's been copied out |
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* and updating header, then send each fragment (in order). |
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*/ |
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m = m0; |
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m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); |
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ip->ip_len = htons((u_int16_t)m->m_len); |
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ip->ip_off = htons((u_int16_t)(ip->ip_off | IP_MF)); |
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ip->ip_sum = 0; |
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ip->ip_sum = cksum(m, hlen); |
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sendorfree: |
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for (m = m0; m; m = m0) { |
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m0 = m->m_nextpkt; |
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m->m_nextpkt = 0; |
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if (error == 0) |
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if_output(so, m); |
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else |
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m_freem(m); |
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} |
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|
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if (error == 0) |
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ipstat.ips_fragmented++; |
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} |
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|
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done: |
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return (error); |
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|
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bad: |
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m_freem(m0); |
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goto done; |
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} |
