The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 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. |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 13 | * 3. Neither the name of the University nor the names of its contributors |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 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 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 45 | /* Number of packets queued before we start sending |
| 46 | * (to prevent allocing too many mbufs) */ |
| 47 | #define IF_THRESH 10 |
| 48 | |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 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 |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 56 | ip_output(struct socket *so, struct mbuf *m0) |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 57 | { |
| 58 | register struct ip *ip; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 59 | register struct mbuf *m = m0; |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 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); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 66 | |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 67 | /* We do no options */ |
| 68 | /* if (opt) { |
| 69 | * m = ip_insertoptions(m, opt, &len); |
| 70 | * hlen = len; |
| 71 | * } |
| 72 | */ |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 73 | ip = mtod(m, struct ip *); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 74 | /* |
| 75 | * Fill in IP header. |
| 76 | */ |
| 77 | ip->ip_v = IPVERSION; |
| 78 | ip->ip_off &= IP_DF; |
| 79 | ip->ip_id = htons(ip_id++); |
| 80 | ip->ip_hl = hlen >> 2; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 81 | STAT(ipstat.ips_localout++); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 82 | |
| 83 | /* |
| 84 | * Verify that we have any chance at all of being able to queue |
| 85 | * the packet or packet fragments |
| 86 | */ |
| 87 | /* XXX Hmmm... */ |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 88 | /* if (if_queued > IF_THRESH && towrite <= 0) { |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 89 | * error = ENOBUFS; |
| 90 | * goto bad; |
| 91 | * } |
| 92 | */ |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 93 | |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 94 | /* |
| 95 | * If small enough for interface, can just send directly. |
| 96 | */ |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 97 | if ((u_int16_t)ip->ip_len <= IF_MTU) { |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 98 | ip->ip_len = htons((u_int16_t)ip->ip_len); |
| 99 | ip->ip_off = htons((u_int16_t)ip->ip_off); |
| 100 | ip->ip_sum = 0; |
| 101 | ip->ip_sum = cksum(m, hlen); |
| 102 | |
| 103 | if_output(so, m); |
| 104 | goto done; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Too large for interface; fragment if possible. |
| 109 | * Must be able to put at least 8 bytes per fragment. |
| 110 | */ |
| 111 | if (ip->ip_off & IP_DF) { |
| 112 | error = -1; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 113 | STAT(ipstat.ips_cantfrag++); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 114 | goto bad; |
| 115 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 116 | |
| 117 | len = (IF_MTU - hlen) &~ 7; /* ip databytes per packet */ |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 118 | if (len < 8) { |
| 119 | error = -1; |
| 120 | goto bad; |
| 121 | } |
| 122 | |
| 123 | { |
| 124 | int mhlen, firstlen = len; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 125 | struct mbuf **mnext = &m->m_nextpkt; |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 126 | |
| 127 | /* |
| 128 | * Loop through length of segment after first fragment, |
| 129 | * make new header and copy data of each part and link onto chain. |
| 130 | */ |
| 131 | m0 = m; |
| 132 | mhlen = sizeof (struct ip); |
| 133 | for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { |
| 134 | register struct ip *mhip; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 135 | m = m_get(); |
| 136 | if (m == NULL) { |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 137 | error = -1; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 138 | STAT(ipstat.ips_odropped++); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 139 | goto sendorfree; |
| 140 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 141 | m->m_data += IF_MAXLINKHDR; |
| 142 | mhip = mtod(m, struct ip *); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 143 | *mhip = *ip; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 144 | |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 145 | /* No options */ |
| 146 | /* if (hlen > sizeof (struct ip)) { |
| 147 | * mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); |
| 148 | * mhip->ip_hl = mhlen >> 2; |
| 149 | * } |
| 150 | */ |
| 151 | m->m_len = mhlen; |
| 152 | mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); |
| 153 | if (ip->ip_off & IP_MF) |
| 154 | mhip->ip_off |= IP_MF; |
| 155 | if (off + len >= (u_int16_t)ip->ip_len) |
| 156 | len = (u_int16_t)ip->ip_len - off; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 157 | else |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 158 | mhip->ip_off |= IP_MF; |
| 159 | mhip->ip_len = htons((u_int16_t)(len + mhlen)); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 160 | |
| 161 | if (m_copy(m, m0, off, len) < 0) { |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 162 | error = -1; |
| 163 | goto sendorfree; |
| 164 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 165 | |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 166 | mhip->ip_off = htons((u_int16_t)mhip->ip_off); |
| 167 | mhip->ip_sum = 0; |
| 168 | mhip->ip_sum = cksum(m, mhlen); |
| 169 | *mnext = m; |
| 170 | mnext = &m->m_nextpkt; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 171 | STAT(ipstat.ips_ofragments++); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 172 | } |
| 173 | /* |
| 174 | * Update first fragment by trimming what's been copied out |
| 175 | * and updating header, then send each fragment (in order). |
| 176 | */ |
| 177 | m = m0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 178 | m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 179 | ip->ip_len = htons((u_int16_t)m->m_len); |
| 180 | ip->ip_off = htons((u_int16_t)(ip->ip_off | IP_MF)); |
| 181 | ip->ip_sum = 0; |
| 182 | ip->ip_sum = cksum(m, hlen); |
| 183 | sendorfree: |
| 184 | for (m = m0; m; m = m0) { |
| 185 | m0 = m->m_nextpkt; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 186 | m->m_nextpkt = NULL; |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 187 | if (error == 0) |
| 188 | if_output(so, m); |
| 189 | else |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 190 | m_freem(m); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 191 | } |
| 192 | |
| 193 | if (error == 0) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 194 | STAT(ipstat.ips_fragmented++); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 195 | } |
| 196 | |
| 197 | done: |
| 198 | return (error); |
| 199 | |
| 200 | bad: |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 201 | m_freem(m0); |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 202 | goto done; |
| 203 | } |