1 /* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $ */ 2 3 /* 4 * Copyright (c) 1992 Regents of the University of California. 5 * All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL) 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/socket.h> 43 44 #include <string.h> 45 46 #include <net/if.h> 47 #include <netinet/in.h> 48 #include <netinet/if_ether.h> 49 #include <netinet/in_systm.h> 50 51 #include <netinet/in_pcb.h> 52 #include <netinet/ip.h> 53 #include <netinet/ip_var.h> 54 #include <netinet/udp.h> 55 #include <netinet/udp_var.h> 56 57 #include "stand.h" 58 #include "net.h" 59 60 /* Caller must leave room for ethernet, ip and udp headers in front!! */ 61 ssize_t 62 sendudp(struct iodesc *d, void *pkt, size_t len) 63 { 64 ssize_t cc; 65 struct udpiphdr *ui; 66 struct udphdr *uh; 67 68 #ifdef NET_DEBUG 69 if (debug) { 70 printf("sendudp: d=%lx called.\n", (long)d); 71 if (d) { 72 printf("saddr: %s:%d", 73 inet_ntoa(d->myip), ntohs(d->myport)); 74 printf(" daddr: %s:%d\n", 75 inet_ntoa(d->destip), ntohs(d->destport)); 76 } 77 } 78 #endif 79 80 ui = (struct udpiphdr *)pkt - 1; 81 bzero(ui, sizeof(*ui)); 82 83 uh = (struct udphdr *)pkt - 1; 84 len += sizeof(*uh); 85 86 uh->uh_sport = d->myport; 87 uh->uh_dport = d->destport; 88 uh->uh_ulen = htons(len); 89 90 ui->ui_pr = IPPROTO_UDP; 91 ui->ui_len = uh->uh_ulen; 92 ui->ui_src = d->myip; 93 ui->ui_dst = d->destip; 94 95 #ifndef UDP_NO_CKSUM 96 uh->uh_sum = in_cksum(ui, len + sizeof (struct ip)); 97 #endif 98 99 cc = sendip(d, uh, len, IPPROTO_UDP); 100 if (cc == -1) 101 return (-1); 102 if (cc != len) 103 panic("sendudp: bad write (%zd != %zd)", cc, len); 104 return (cc - sizeof(*uh)); 105 } 106 107 /* 108 * Receive a UDP packet and validate it is for us. 109 */ 110 ssize_t 111 readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft) 112 { 113 ssize_t n; 114 struct udphdr *uh; 115 void *ptr; 116 117 #ifdef NET_DEBUG 118 if (debug) 119 printf("readudp: called\n"); 120 #endif 121 122 uh = NULL; 123 ptr = NULL; 124 n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP); 125 if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) { 126 free(ptr); 127 return (-1); 128 } 129 130 if (uh->uh_dport != d->myport) { 131 #ifdef NET_DEBUG 132 if (debug) 133 printf("readudp: bad dport %d != %d\n", 134 d->myport, ntohs(uh->uh_dport)); 135 #endif 136 free(ptr); 137 return (-1); 138 } 139 140 #ifndef UDP_NO_CKSUM 141 if (uh->uh_sum) { 142 struct udpiphdr *ui; 143 struct ip *ip; 144 struct ip tip; 145 146 n = ntohs(uh->uh_ulen) + sizeof(*ip); 147 148 /* Check checksum (must save and restore ip header) */ 149 ip = (struct ip *)uh - 1; 150 tip = *ip; 151 ui = (struct udpiphdr *)ip; 152 bzero(&ui->ui_x1, sizeof(ui->ui_x1)); 153 ui->ui_len = uh->uh_ulen; 154 if (in_cksum(ui, n) != 0) { 155 #ifdef NET_DEBUG 156 if (debug) 157 printf("readudp: bad cksum\n"); 158 #endif 159 free(ptr); 160 return (-1); 161 } 162 *ip = tip; 163 } 164 #endif 165 if (ntohs(uh->uh_ulen) < sizeof(*uh)) { 166 #ifdef NET_DEBUG 167 if (debug) 168 printf("readudp: bad udp len %d < %d\n", 169 ntohs(uh->uh_ulen), (int)sizeof(*uh)); 170 #endif 171 free(ptr); 172 return (-1); 173 } 174 175 n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ? 176 ntohs(uh->uh_ulen) - sizeof(*uh) : n; 177 *pkt = ptr; 178 *payload = (void *)((uintptr_t)uh + sizeof(*uh)); 179 return (n); 180 } 181