![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to ip_output.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Qemu by Fabrice Bellard] / qemu / slirp|
Return to ip_output.c CVS log | Up to [Qemu by Fabrice Bellard] / qemu / slirp |
1.1 root 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.
13: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This product includes software developed by the University of
16: * California, Berkeley and its contributors.
17: * 4. Neither the name of the University nor the names of its contributors
18: * may be used to endorse or promote products derived from this software
19: * without specific prior written permission.
20: *
21: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31: * SUCH DAMAGE.
32: *
33: * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
34: * ip_output.c,v 1.9 1994/11/16 10:17:10 jkh Exp
35: */
36:
37: /*
38: * Changes and additions relating to SLiRP are
39: * Copyright (c) 1995 Danny Gasparovski.
40: *
41: * Please read the file COPYRIGHT for the
42: * terms and conditions of the copyright.
43: */
44:
45: #include <slirp.h>
46:
47: u_int16_t ip_id;
48:
1.1.1.2 ! root 49: /* Number of packets queued before we start sending
! 50: * (to prevent allocing too many mbufs) */
! 51: #define IF_THRESH 10
! 52:
1.1 root 53: /*
54: * IP output. The packet in mbuf chain m contains a skeletal IP
55: * header (with len, off, ttl, proto, tos, src, dst).
56: * The mbuf chain containing the packet will be freed.
57: * The mbuf opt, if present, will not be freed.
58: */
59: int
60: ip_output(so, m0)
61: struct socket *so;
62: struct mbuf *m0;
63: {
64: register struct ip *ip;
65: register struct mbuf *m = m0;
66: register int hlen = sizeof(struct ip );
67: int len, off, error = 0;
68:
69: DEBUG_CALL("ip_output");
70: DEBUG_ARG("so = %lx", (long)so);
71: DEBUG_ARG("m0 = %lx", (long)m0);
1.1.1.2 ! root 72:
1.1 root 73: /* We do no options */
74: /* if (opt) {
75: * m = ip_insertoptions(m, opt, &len);
76: * hlen = len;
77: * }
78: */
79: ip = mtod(m, struct ip *);
80: /*
81: * Fill in IP header.
82: */
83: ip->ip_v = IPVERSION;
84: ip->ip_off &= IP_DF;
85: ip->ip_id = htons(ip_id++);
86: ip->ip_hl = hlen >> 2;
1.1.1.2 ! root 87: STAT(ipstat.ips_localout++);
1.1 root 88:
89: /*
90: * Verify that we have any chance at all of being able to queue
91: * the packet or packet fragments
92: */
93: /* XXX Hmmm... */
1.1.1.2 ! root 94: /* if (if_queued > IF_THRESH && towrite <= 0) {
1.1 root 95: * error = ENOBUFS;
96: * goto bad;
97: * }
98: */
1.1.1.2 ! root 99:
1.1 root 100: /*
101: * If small enough for interface, can just send directly.
102: */
1.1.1.2 ! root 103: if ((u_int16_t)ip->ip_len <= IF_MTU) {
1.1 root 104: ip->ip_len = htons((u_int16_t)ip->ip_len);
105: ip->ip_off = htons((u_int16_t)ip->ip_off);
106: ip->ip_sum = 0;
107: ip->ip_sum = cksum(m, hlen);
108:
109: if_output(so, m);
110: goto done;
111: }
112:
113: /*
114: * Too large for interface; fragment if possible.
115: * Must be able to put at least 8 bytes per fragment.
116: */
117: if (ip->ip_off & IP_DF) {
118: error = -1;
1.1.1.2 ! root 119: STAT(ipstat.ips_cantfrag++);
1.1 root 120: goto bad;
121: }
1.1.1.2 ! root 122:
! 123: len = (IF_MTU - hlen) &~ 7; /* ip databytes per packet */
1.1 root 124: if (len < 8) {
125: error = -1;
126: goto bad;
127: }
128:
129: {
130: int mhlen, firstlen = len;
131: struct mbuf **mnext = &m->m_nextpkt;
132:
133: /*
134: * Loop through length of segment after first fragment,
135: * make new header and copy data of each part and link onto chain.
136: */
137: m0 = m;
138: mhlen = sizeof (struct ip);
139: for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) {
140: register struct ip *mhip;
141: m = m_get();
142: if (m == 0) {
143: error = -1;
1.1.1.2 ! root 144: STAT(ipstat.ips_odropped++);
1.1 root 145: goto sendorfree;
146: }
1.1.1.2 ! root 147: m->m_data += IF_MAXLINKHDR;
1.1 root 148: mhip = mtod(m, struct ip *);
149: *mhip = *ip;
1.1.1.2 ! root 150:
1.1 root 151: /* No options */
152: /* if (hlen > sizeof (struct ip)) {
153: * mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
154: * mhip->ip_hl = mhlen >> 2;
155: * }
156: */
157: m->m_len = mhlen;
158: mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF);
159: if (ip->ip_off & IP_MF)
160: mhip->ip_off |= IP_MF;
161: if (off + len >= (u_int16_t)ip->ip_len)
162: len = (u_int16_t)ip->ip_len - off;
1.1.1.2 ! root 163: else
1.1 root 164: mhip->ip_off |= IP_MF;
165: mhip->ip_len = htons((u_int16_t)(len + mhlen));
1.1.1.2 ! root 166:
1.1 root 167: if (m_copy(m, m0, off, len) < 0) {
168: error = -1;
169: goto sendorfree;
170: }
1.1.1.2 ! root 171:
1.1 root 172: mhip->ip_off = htons((u_int16_t)mhip->ip_off);
173: mhip->ip_sum = 0;
174: mhip->ip_sum = cksum(m, mhlen);
175: *mnext = m;
176: mnext = &m->m_nextpkt;
1.1.1.2 ! root 177: STAT(ipstat.ips_ofragments++);
1.1 root 178: }
179: /*
180: * Update first fragment by trimming what's been copied out
181: * and updating header, then send each fragment (in order).
182: */
183: m = m0;
184: m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len);
185: ip->ip_len = htons((u_int16_t)m->m_len);
186: ip->ip_off = htons((u_int16_t)(ip->ip_off | IP_MF));
187: ip->ip_sum = 0;
188: ip->ip_sum = cksum(m, hlen);
189: sendorfree:
190: for (m = m0; m; m = m0) {
191: m0 = m->m_nextpkt;
192: m->m_nextpkt = 0;
193: if (error == 0)
194: if_output(so, m);
195: else
196: m_freem(m);
197: }
198:
199: if (error == 0)
1.1.1.2 ! root 200: STAT(ipstat.ips_fragmented++);
1.1 root 201: }
202:
203: done:
204: return (error);
205:
206: bad:
207: m_freem(m0);
208: goto done;
209: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.