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 36 #include <sys/param.h> 37 #include <sys/socket.h> 38 39 #include <string.h> 40 41 #include <net/if.h> 42 #include <netinet/in.h> 43 #include <netinet/if_ether.h> 44 #include <netinet/in_systm.h> 45 46 #include <netinet/ip.h> 47 #include <netinet/ip_var.h> 48 #include <netinet/udp.h> 49 #include <netinet/udp_var.h> 50 51 #include "stand.h" 52 #include "net.h" 53 54 /* Caller must leave room for ethernet, ip and udp headers in front!! */ 55 ssize_t 56 sendudp(struct iodesc *d, void *pkt, size_t len) 57 { 58 ssize_t cc; 59 struct udpiphdr *ui; 60 struct udphdr *uh; 61 62 #ifdef NET_DEBUG 63 if (debug) { 64 printf("sendudp: d=%lx called.\n", (long)d); 65 if (d) { 66 printf("saddr: %s:%d", 67 inet_ntoa(d->myip), ntohs(d->myport)); 68 printf(" daddr: %s:%d\n", 69 inet_ntoa(d->destip), ntohs(d->destport)); 70 } 71 } 72 #endif 73 74 ui = (struct udpiphdr *)pkt - 1; 75 bzero(ui, sizeof(*ui)); 76 77 uh = (struct udphdr *)pkt - 1; 78 len += sizeof(*uh); 79 80 uh->uh_sport = d->myport; 81 uh->uh_dport = d->destport; 82 uh->uh_ulen = htons(len); 83 84 ui->ui_pr = IPPROTO_UDP; 85 ui->ui_len = uh->uh_ulen; 86 ui->ui_src = d->myip; 87 ui->ui_dst = d->destip; 88 89 #ifndef UDP_NO_CKSUM 90 uh->uh_sum = in_cksum(ui, len + sizeof (struct ip)); 91 #endif 92 93 cc = sendip(d, uh, len, IPPROTO_UDP); 94 if (cc == -1) 95 return (-1); 96 if (cc != len) 97 panic("sendudp: bad write (%zd != %zd)", cc, len); 98 return (cc - sizeof(*uh)); 99 } 100 101 /* 102 * Receive a UDP packet and validate it is for us. 103 */ 104 ssize_t 105 readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft) 106 { 107 ssize_t n; 108 struct udphdr *uh; 109 void *ptr; 110 111 #ifdef NET_DEBUG 112 if (debug) 113 printf("readudp: called\n"); 114 #endif 115 116 uh = NULL; 117 ptr = NULL; 118 n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP); 119 if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) { 120 free(ptr); 121 return (-1); 122 } 123 124 if (uh->uh_dport != d->myport) { 125 #ifdef NET_DEBUG 126 if (debug) 127 printf("readudp: bad dport %d != %d\n", 128 d->myport, ntohs(uh->uh_dport)); 129 #endif 130 free(ptr); 131 return (-1); 132 } 133 134 #ifndef UDP_NO_CKSUM 135 if (uh->uh_sum) { 136 struct udpiphdr *ui; 137 struct ip *ip; 138 struct ip tip; 139 140 n = ntohs(uh->uh_ulen) + sizeof(*ip); 141 142 /* Check checksum (must save and restore ip header) */ 143 ip = (struct ip *)uh - 1; 144 tip = *ip; 145 ui = (struct udpiphdr *)ip; 146 bzero(&ui->ui_x1, sizeof(ui->ui_x1)); 147 ui->ui_len = uh->uh_ulen; 148 if (in_cksum(ui, n) != 0) { 149 #ifdef NET_DEBUG 150 if (debug) 151 printf("readudp: bad cksum\n"); 152 #endif 153 free(ptr); 154 return (-1); 155 } 156 *ip = tip; 157 } 158 #endif 159 if (ntohs(uh->uh_ulen) < sizeof(*uh)) { 160 #ifdef NET_DEBUG 161 if (debug) 162 printf("readudp: bad udp len %d < %d\n", 163 ntohs(uh->uh_ulen), (int)sizeof(*uh)); 164 #endif 165 free(ptr); 166 return (-1); 167 } 168 169 n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ? 170 ntohs(uh->uh_ulen) - sizeof(*uh) : n; 171 *pkt = ptr; 172 *payload = (void *)((uintptr_t)uh + sizeof(*uh)); 173 return (n); 174 } 175