]>
Commit | Line | Data |
---|---|---|
f0cbd3ec FB |
1 | /* |
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. | |
2f5f8996 | 13 | * 3. Neither the name of the University nor the names of its contributors |
f0cbd3ec FB |
14 | * 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 | ||
43 | u_int16_t ip_id; | |
44 | ||
7878ff6b BS |
45 | /* Number of packets queued before we start sending |
46 | * (to prevent allocing too many mbufs) */ | |
47 | #define IF_THRESH 10 | |
48 | ||
f0cbd3ec FB |
49 | /* |
50 | * IP output. The packet in mbuf chain m contains a skeletal IP | |
51 | * header (with len, off, ttl, proto, tos, src, dst). | |
52 | * The mbuf chain containing the packet will be freed. | |
53 | * The mbuf opt, if present, will not be freed. | |
54 | */ | |
55 | int | |
511d2b14 | 56 | ip_output(struct socket *so, struct mbuf *m0) |
f0cbd3ec FB |
57 | { |
58 | register struct ip *ip; | |
59 | register struct mbuf *m = m0; | |
60 | register int hlen = sizeof(struct ip ); | |
61 | int len, off, error = 0; | |
62 | ||
63 | DEBUG_CALL("ip_output"); | |
64 | DEBUG_ARG("so = %lx", (long)so); | |
65 | DEBUG_ARG("m0 = %lx", (long)m0); | |
5fafdf24 | 66 | |
f0cbd3ec FB |
67 | ip = mtod(m, struct ip *); |
68 | /* | |
69 | * Fill in IP header. | |
70 | */ | |
71 | ip->ip_v = IPVERSION; | |
72 | ip->ip_off &= IP_DF; | |
73 | ip->ip_id = htons(ip_id++); | |
74 | ip->ip_hl = hlen >> 2; | |
31a60e22 | 75 | STAT(ipstat.ips_localout++); |
f0cbd3ec | 76 | |
f0cbd3ec FB |
77 | /* |
78 | * If small enough for interface, can just send directly. | |
79 | */ | |
9634d903 | 80 | if ((u_int16_t)ip->ip_len <= IF_MTU) { |
f0cbd3ec FB |
81 | ip->ip_len = htons((u_int16_t)ip->ip_len); |
82 | ip->ip_off = htons((u_int16_t)ip->ip_off); | |
83 | ip->ip_sum = 0; | |
84 | ip->ip_sum = cksum(m, hlen); | |
85 | ||
86 | if_output(so, m); | |
87 | goto done; | |
88 | } | |
89 | ||
90 | /* | |
91 | * Too large for interface; fragment if possible. | |
92 | * Must be able to put at least 8 bytes per fragment. | |
93 | */ | |
94 | if (ip->ip_off & IP_DF) { | |
95 | error = -1; | |
31a60e22 | 96 | STAT(ipstat.ips_cantfrag++); |
f0cbd3ec FB |
97 | goto bad; |
98 | } | |
5fafdf24 | 99 | |
9634d903 | 100 | len = (IF_MTU - hlen) &~ 7; /* ip databytes per packet */ |
f0cbd3ec FB |
101 | if (len < 8) { |
102 | error = -1; | |
103 | goto bad; | |
104 | } | |
105 | ||
106 | { | |
107 | int mhlen, firstlen = len; | |
108 | struct mbuf **mnext = &m->m_nextpkt; | |
109 | ||
110 | /* | |
111 | * Loop through length of segment after first fragment, | |
112 | * make new header and copy data of each part and link onto chain. | |
113 | */ | |
114 | m0 = m; | |
115 | mhlen = sizeof (struct ip); | |
116 | for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { | |
117 | register struct ip *mhip; | |
118 | m = m_get(); | |
511d2b14 | 119 | if (m == NULL) { |
f0cbd3ec | 120 | error = -1; |
31a60e22 | 121 | STAT(ipstat.ips_odropped++); |
f0cbd3ec FB |
122 | goto sendorfree; |
123 | } | |
9634d903 | 124 | m->m_data += IF_MAXLINKHDR; |
f0cbd3ec FB |
125 | mhip = mtod(m, struct ip *); |
126 | *mhip = *ip; | |
3b46e624 | 127 | |
f0cbd3ec FB |
128 | m->m_len = mhlen; |
129 | mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); | |
130 | if (ip->ip_off & IP_MF) | |
131 | mhip->ip_off |= IP_MF; | |
132 | if (off + len >= (u_int16_t)ip->ip_len) | |
133 | len = (u_int16_t)ip->ip_len - off; | |
5fafdf24 | 134 | else |
f0cbd3ec FB |
135 | mhip->ip_off |= IP_MF; |
136 | mhip->ip_len = htons((u_int16_t)(len + mhlen)); | |
3b46e624 | 137 | |
f0cbd3ec FB |
138 | if (m_copy(m, m0, off, len) < 0) { |
139 | error = -1; | |
140 | goto sendorfree; | |
141 | } | |
3b46e624 | 142 | |
f0cbd3ec FB |
143 | mhip->ip_off = htons((u_int16_t)mhip->ip_off); |
144 | mhip->ip_sum = 0; | |
145 | mhip->ip_sum = cksum(m, mhlen); | |
146 | *mnext = m; | |
147 | mnext = &m->m_nextpkt; | |
31a60e22 | 148 | STAT(ipstat.ips_ofragments++); |
f0cbd3ec FB |
149 | } |
150 | /* | |
151 | * Update first fragment by trimming what's been copied out | |
152 | * and updating header, then send each fragment (in order). | |
153 | */ | |
154 | m = m0; | |
155 | m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); | |
156 | ip->ip_len = htons((u_int16_t)m->m_len); | |
157 | ip->ip_off = htons((u_int16_t)(ip->ip_off | IP_MF)); | |
158 | ip->ip_sum = 0; | |
159 | ip->ip_sum = cksum(m, hlen); | |
160 | sendorfree: | |
161 | for (m = m0; m; m = m0) { | |
162 | m0 = m->m_nextpkt; | |
511d2b14 | 163 | m->m_nextpkt = NULL; |
f0cbd3ec FB |
164 | if (error == 0) |
165 | if_output(so, m); | |
166 | else | |
167 | m_freem(m); | |
168 | } | |
169 | ||
170 | if (error == 0) | |
31a60e22 | 171 | STAT(ipstat.ips_fragmented++); |
f0cbd3ec FB |
172 | } |
173 | ||
174 | done: | |
175 | return (error); | |
176 | ||
177 | bad: | |
178 | m_freem(m0); | |
179 | goto done; | |
180 | } |