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bellardf0cbd3e2004-04-22 00:10:48 +00001/*
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
aliguori2f5f8992009-01-26 19:37:41 +000013 * 3. Neither the name of the University nor the names of its contributors
bellardf0cbd3e2004-04-22 00:10:48 +000014 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
30 * ip_output.c,v 1.9 1994/11/16 10:17:10 jkh Exp
31 */
32
33/*
34 * Changes and additions relating to SLiRP are
35 * Copyright (c) 1995 Danny Gasparovski.
36 *
37 * Please read the file COPYRIGHT for the
38 * terms and conditions of the copyright.
39 */
40
41#include <slirp.h>
42
blueswir17878ff62007-10-26 19:34:46 +000043/* Number of packets queued before we start sending
44 * (to prevent allocing too many mbufs) */
45#define IF_THRESH 10
46
bellardf0cbd3e2004-04-22 00:10:48 +000047/*
48 * IP output. The packet in mbuf chain m contains a skeletal IP
49 * header (with len, off, ttl, proto, tos, src, dst).
50 * The mbuf chain containing the packet will be freed.
51 * The mbuf opt, if present, will not be freed.
52 */
53int
blueswir1511d2b12009-03-07 15:32:56 +000054ip_output(struct socket *so, struct mbuf *m0)
bellardf0cbd3e2004-04-22 00:10:48 +000055{
Jan Kiszka460fec62009-06-24 14:42:31 +020056 Slirp *slirp = m0->slirp;
bellardf0cbd3e2004-04-22 00:10:48 +000057 register struct ip *ip;
58 register struct mbuf *m = m0;
59 register int hlen = sizeof(struct ip );
60 int len, off, error = 0;
61
62 DEBUG_CALL("ip_output");
63 DEBUG_ARG("so = %lx", (long)so);
64 DEBUG_ARG("m0 = %lx", (long)m0);
ths5fafdf22007-09-16 21:08:06 +000065
bellardf0cbd3e2004-04-22 00:10:48 +000066 ip = mtod(m, struct ip *);
67 /*
68 * Fill in IP header.
69 */
70 ip->ip_v = IPVERSION;
71 ip->ip_off &= IP_DF;
Jan Kiszka460fec62009-06-24 14:42:31 +020072 ip->ip_id = htons(slirp->ip_id++);
bellardf0cbd3e2004-04-22 00:10:48 +000073 ip->ip_hl = hlen >> 2;
bellardf0cbd3e2004-04-22 00:10:48 +000074
75 /*
bellardf0cbd3e2004-04-22 00:10:48 +000076 * If small enough for interface, can just send directly.
77 */
Stefan Weilb6dce922010-07-22 22:15:23 +020078 if ((uint16_t)ip->ip_len <= IF_MTU) {
79 ip->ip_len = htons((uint16_t)ip->ip_len);
80 ip->ip_off = htons((uint16_t)ip->ip_off);
bellardf0cbd3e2004-04-22 00:10:48 +000081 ip->ip_sum = 0;
82 ip->ip_sum = cksum(m, hlen);
83
84 if_output(so, m);
85 goto done;
86 }
87
88 /*
89 * Too large for interface; fragment if possible.
90 * Must be able to put at least 8 bytes per fragment.
91 */
92 if (ip->ip_off & IP_DF) {
93 error = -1;
bellardf0cbd3e2004-04-22 00:10:48 +000094 goto bad;
95 }
ths5fafdf22007-09-16 21:08:06 +000096
blueswir19634d902007-10-26 19:01:16 +000097 len = (IF_MTU - hlen) &~ 7; /* ip databytes per packet */
bellardf0cbd3e2004-04-22 00:10:48 +000098 if (len < 8) {
99 error = -1;
100 goto bad;
101 }
102
103 {
104 int mhlen, firstlen = len;
105 struct mbuf **mnext = &m->m_nextpkt;
106
107 /*
108 * Loop through length of segment after first fragment,
109 * make new header and copy data of each part and link onto chain.
110 */
111 m0 = m;
112 mhlen = sizeof (struct ip);
Stefan Weilb6dce922010-07-22 22:15:23 +0200113 for (off = hlen + len; off < (uint16_t)ip->ip_len; off += len) {
bellardf0cbd3e2004-04-22 00:10:48 +0000114 register struct ip *mhip;
Jan Kiszka460fec62009-06-24 14:42:31 +0200115 m = m_get(slirp);
blueswir1511d2b12009-03-07 15:32:56 +0000116 if (m == NULL) {
bellardf0cbd3e2004-04-22 00:10:48 +0000117 error = -1;
bellardf0cbd3e2004-04-22 00:10:48 +0000118 goto sendorfree;
119 }
blueswir19634d902007-10-26 19:01:16 +0000120 m->m_data += IF_MAXLINKHDR;
bellardf0cbd3e2004-04-22 00:10:48 +0000121 mhip = mtod(m, struct ip *);
122 *mhip = *ip;
ths3b46e622007-09-17 08:09:54 +0000123
bellardf0cbd3e2004-04-22 00:10:48 +0000124 m->m_len = mhlen;
125 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF);
126 if (ip->ip_off & IP_MF)
127 mhip->ip_off |= IP_MF;
Stefan Weilb6dce922010-07-22 22:15:23 +0200128 if (off + len >= (uint16_t)ip->ip_len)
129 len = (uint16_t)ip->ip_len - off;
ths5fafdf22007-09-16 21:08:06 +0000130 else
bellardf0cbd3e2004-04-22 00:10:48 +0000131 mhip->ip_off |= IP_MF;
Stefan Weilb6dce922010-07-22 22:15:23 +0200132 mhip->ip_len = htons((uint16_t)(len + mhlen));
ths3b46e622007-09-17 08:09:54 +0000133
bellardf0cbd3e2004-04-22 00:10:48 +0000134 if (m_copy(m, m0, off, len) < 0) {
135 error = -1;
136 goto sendorfree;
137 }
ths3b46e622007-09-17 08:09:54 +0000138
Stefan Weilb6dce922010-07-22 22:15:23 +0200139 mhip->ip_off = htons((uint16_t)mhip->ip_off);
bellardf0cbd3e2004-04-22 00:10:48 +0000140 mhip->ip_sum = 0;
141 mhip->ip_sum = cksum(m, mhlen);
142 *mnext = m;
143 mnext = &m->m_nextpkt;
bellardf0cbd3e2004-04-22 00:10:48 +0000144 }
145 /*
146 * Update first fragment by trimming what's been copied out
147 * and updating header, then send each fragment (in order).
148 */
149 m = m0;
Stefan Weilb6dce922010-07-22 22:15:23 +0200150 m_adj(m, hlen + firstlen - (uint16_t)ip->ip_len);
151 ip->ip_len = htons((uint16_t)m->m_len);
152 ip->ip_off = htons((uint16_t)(ip->ip_off | IP_MF));
bellardf0cbd3e2004-04-22 00:10:48 +0000153 ip->ip_sum = 0;
154 ip->ip_sum = cksum(m, hlen);
155sendorfree:
156 for (m = m0; m; m = m0) {
157 m0 = m->m_nextpkt;
blueswir1511d2b12009-03-07 15:32:56 +0000158 m->m_nextpkt = NULL;
bellardf0cbd3e2004-04-22 00:10:48 +0000159 if (error == 0)
160 if_output(so, m);
161 else
Jan Kiszka3acccfc2011-07-20 12:20:16 +0200162 m_free(m);
bellardf0cbd3e2004-04-22 00:10:48 +0000163 }
bellardf0cbd3e2004-04-22 00:10:48 +0000164 }
165
166done:
167 return (error);
168
169bad:
Jan Kiszka3acccfc2011-07-20 12:20:16 +0200170 m_free(m0);
bellardf0cbd3e2004-04-22 00:10:48 +0000171 goto done;
172}