1 /* $NetBSD: net.c,v 1.4 1995/02/20 11:04:08 mycroft 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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Lawrence Berkeley Laboratory and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL) 40 */ 41 42 #include <sys/param.h> 43 #include <sys/socket.h> 44 45 #include <string.h> 46 47 #include <net/if.h> 48 49 #include <netinet/in.h> 50 #include <netinet/if_ether.h> 51 #include <netinet/in_systm.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 #include "netif.h" 60 61 n_long myip; 62 63 /* Caller must leave room for ethernet, ip and udp headers in front!! */ 64 size_t 65 sendudp(d, pkt, len) 66 register struct iodesc *d; 67 register void *pkt; 68 register size_t len; 69 { 70 register size_t cc; 71 register struct ip *ip; 72 register struct udpiphdr *ui; 73 register struct udphdr *uh; 74 register u_char *ea; 75 struct ip tip; 76 77 #ifdef NET_DEBUG 78 if (debug) { 79 printf("sendudp: d=%x called.\n", (u_int)d); 80 if (d) { 81 printf("saddr: %s:%d", 82 intoa(d->myip), d->myport); 83 printf(" daddr: %s:%d\n", 84 intoa(d->destip), d->destport); 85 } 86 } 87 #endif 88 89 uh = (struct udphdr *)pkt - 1; 90 ip = (struct ip *)uh - 1; 91 len += sizeof(*ip) + sizeof(*uh); 92 93 bzero(ip, sizeof(*ip) + sizeof(*uh)); 94 95 ip->ip_v = IPVERSION; /* half-char */ 96 ip->ip_hl = sizeof(*ip) >> 2; /* half-char */ 97 ip->ip_len = htons(len); 98 ip->ip_p = IPPROTO_UDP; /* char */ 99 ip->ip_ttl = IP_TTL; /* char */ 100 ip->ip_src.s_addr = htonl(d->myip); 101 ip->ip_dst.s_addr = htonl(d->destip); 102 ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */ 103 104 uh->uh_sport = htons(d->myport); 105 uh->uh_dport = htons(d->destport); 106 uh->uh_ulen = htons(len - sizeof(*ip)); 107 108 /* Calculate checksum (must save and restore ip header) */ 109 tip = *ip; 110 ui = (struct udpiphdr *)ip; 111 ui->ui_next = 0; 112 ui->ui_prev = 0; 113 ui->ui_x1 = 0; 114 ui->ui_len = uh->uh_ulen; 115 uh->uh_sum = in_cksum(ui, len); 116 *ip = tip; 117 118 if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 || 119 mask == 0 || SAMENET(ip->ip_src.s_addr, ip->ip_dst.s_addr, mask)) 120 ea = arpwhohas(d, ip->ip_dst.s_addr); 121 else 122 ea = arpwhohas(d, htonl(gateip)); 123 124 cc = sendether(d, ip, len, ea, ETHERTYPE_IP); 125 if (cc == -1) 126 return (-1); 127 if (cc != len) 128 panic("sendudp: bad write (%d != %d)", cc, len); 129 return (cc - (sizeof(*ip) + sizeof(*uh))); 130 } 131 132 /* Check that packet is a valid udp packet for us */ 133 size_t 134 readudp(d, pkt, len, tleft) 135 register struct iodesc *d; 136 register void *pkt; 137 register size_t len; 138 time_t tleft; 139 { 140 register size_t hlen; 141 register struct ether_header *eh; 142 register struct ip *ip; 143 register struct udphdr *uh; 144 register struct udpiphdr *ui; 145 struct ip tip; 146 147 #ifdef NET_DEBUG 148 if (debug) 149 printf("readudp: called\n"); 150 #endif 151 152 uh = (struct udphdr *)pkt - 1; 153 ip = (struct ip *)uh - 1; 154 155 len = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft); 156 if (len == -1 || len < sizeof(*ip) + sizeof(*uh)) 157 goto bad; 158 159 eh = (struct ether_header *)ip - 1; 160 /* Must be to us */ 161 if (bcmp(d->myea, eh->ether_dhost, 6) != 0 && 162 bcmp(bcea, eh->ether_dhost, 6) != 0) { 163 #ifdef NET_DEBUG 164 if (debug) 165 printf("readudp: not ours. myea=%s bcea=%s\n", 166 ether_sprintf(d->myea), ether_sprintf(bcea)); 167 #endif 168 goto bad; 169 } 170 if (ntohs(eh->ether_type) != ETHERTYPE_IP) { 171 #ifdef NET_DEBUG 172 if (debug) 173 printf("readudp: not IP. ether_type=%x\n", eh->ether_type); 174 #endif 175 goto bad; 176 } 177 178 /* Check ip header */ 179 if (ip->ip_v != IPVERSION || 180 ip->ip_p != IPPROTO_UDP) { /* half char */ 181 #ifdef NET_DEBUG 182 if (debug) 183 printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p); 184 #endif 185 goto bad; 186 } 187 188 hlen = ip->ip_hl << 2; 189 if (hlen < sizeof(*ip) || 190 in_cksum(ip, hlen) != 0) { 191 #ifdef NET_DEBUG 192 if (debug) 193 printf("readudp: short hdr or bad cksum.\n"); 194 #endif 195 goto bad; 196 } 197 NTOHS(ip->ip_len); 198 if (len < ip->ip_len) { 199 #ifdef NET_DEBUG 200 if (debug) 201 printf("readudp: bad length %d < %d.\n", 202 len, ip->ip_len); 203 #endif 204 goto bad; 205 } 206 if (d->myip && ntohl(ip->ip_dst.s_addr) != d->myip) { 207 #ifdef NET_DEBUG 208 if (debug) { 209 printf("readudp: bad saddr %s != ", intoa(d->myip)); 210 printf("%s\n", intoa(ntohl(ip->ip_dst.s_addr))); 211 } 212 #endif 213 goto bad; 214 } 215 216 /* If there were ip options, make them go away */ 217 if (hlen != sizeof(*ip)) { 218 bcopy(((u_char *)ip) + hlen, uh, len - hlen); 219 ip->ip_len = sizeof(*ip); 220 len -= hlen - sizeof(*ip); 221 } 222 if (ntohs(uh->uh_dport) != d->myport) { 223 #ifdef NET_DEBUG 224 if (debug) 225 printf("readudp: bad dport %d != %d\n", 226 d->myport, ntohs(uh->uh_dport)); 227 #endif 228 goto bad; 229 } 230 231 if (uh->uh_sum) { 232 len = ntohs(uh->uh_ulen) + sizeof(*ip); 233 if (len > RECV_SIZE - sizeof(*eh)) { 234 printf("readudp: huge packet, udp len %d\n", len); 235 goto bad; 236 } 237 238 /* Check checksum (must save and restore ip header) */ 239 tip = *ip; 240 ui = (struct udpiphdr *)ip; 241 ui->ui_next = 0; 242 ui->ui_prev = 0; 243 ui->ui_x1 = 0; 244 ui->ui_len = uh->uh_ulen; 245 if (in_cksum(ui, len) != 0) { 246 #ifdef NET_DEBUG 247 if (debug) 248 printf("readudp: bad cksum\n"); 249 #endif 250 *ip = tip; 251 goto bad; 252 } 253 *ip = tip; 254 } 255 NTOHS(uh->uh_dport); 256 NTOHS(uh->uh_sport); 257 NTOHS(uh->uh_ulen); 258 if (uh->uh_ulen < sizeof(*uh)) { 259 #ifdef NET_DEBUG 260 if (debug) 261 printf("readudp: bad udp len %d < %d\n", 262 uh->uh_ulen, sizeof(*uh)); 263 #endif 264 goto bad; 265 } 266 267 len -= sizeof(*ip) + sizeof(*uh); 268 return (len); 269 270 bad: 271 return (-1); 272 } 273 274 /* 275 * Send a packet and wait for a reply, with exponential backoff. 276 * 277 * The send routine must return the actual number of bytes written. 278 * 279 * The receive routine can indicate success by returning the number of 280 * bytes read; it can return 0 to indicate EOF; it can return -1 with a 281 * non-zero errno to indicate failure; finally, it can return -1 with a 282 * zero errno to indicate it isn't done yet. 283 */ 284 size_t 285 sendrecv(d, sproc, sbuf, ssize, rproc, rbuf, rsize) 286 register struct iodesc *d; 287 register size_t (*sproc)(struct iodesc *, void *, size_t); 288 register void *sbuf; 289 register size_t ssize; 290 register size_t (*rproc)(struct iodesc *, void *, size_t, time_t); 291 register void *rbuf; 292 register size_t rsize; 293 { 294 register size_t cc; 295 register time_t t, tmo, tlast, tleft; 296 297 #ifdef NET_DEBUG 298 if (debug) 299 printf("sendrecv: called\n"); 300 #endif 301 302 tmo = MINTMO; 303 tlast = tleft = 0; 304 t = getsecs(); 305 for (;;) { 306 if (tleft <= 0) { 307 cc = (*sproc)(d, sbuf, ssize); 308 if (cc == -1 || cc < ssize) 309 panic("sendrecv: short write! (%d < %d)", 310 cc, ssize); 311 312 tleft = tmo; 313 tmo <<= 1; 314 if (tmo > MAXTMO) 315 tmo = MAXTMO; 316 tlast = t; 317 } 318 319 /* Try to get a packet and process it. */ 320 cc = (*rproc)(d, rbuf, rsize, tleft); 321 /* Return on data, EOF or real error. */ 322 if (cc != -1 || errno != 0) 323 return (cc); 324 325 /* Timed out or didn't get the packet we're waiting for */ 326 t = getsecs(); 327 tleft -= t - tlast; 328 tlast = t; 329 } 330 } 331 332 /* Similar to inet_ntoa() */ 333 char * 334 intoa(addr) 335 n_long addr; 336 { 337 register char *cp; 338 register u_int byte; 339 register int n; 340 static char buf[17]; /* strlen(".255.255.255.255") + 1 */ 341 342 cp = &buf[sizeof buf]; 343 *--cp = '\0'; 344 345 n = 4; 346 do { 347 byte = addr & 0xff; 348 *--cp = byte % 10 + '0'; 349 byte /= 10; 350 if (byte > 0) { 351 *--cp = byte % 10 + '0'; 352 byte /= 10; 353 if (byte > 0) 354 *--cp = byte + '0'; 355 } 356 *--cp = '.'; 357 addr >>= 8; 358 } while (--n > 0); 359 360 return (cp+1); 361 } 362 363 static char * 364 number(s, n) 365 char *s; 366 int *n; 367 { 368 for (*n = 0; isdigit(*s); s++) 369 *n = (*n * 10) + *s - '0'; 370 return s; 371 } 372 373 n_long 374 ip_convertaddr(p) 375 char *p; 376 { 377 #define IP_ANYADDR 0 378 n_long addr = 0, n; 379 380 if (p == (char *)0 || *p == '\0') 381 return IP_ANYADDR; 382 p = number(p, &n); 383 addr |= (n << 24) & 0xff000000; 384 if (*p == '\0' || *p++ != '.') 385 return IP_ANYADDR; 386 p = number(p, &n); 387 addr |= (n << 16) & 0xff0000; 388 if (*p == '\0' || *p++ != '.') 389 return IP_ANYADDR; 390 p = number(p, &n); 391 addr |= (n << 8) & 0xff00; 392 if (*p == '\0' || *p++ != '.') 393 return IP_ANYADDR; 394 p = number(p, &n); 395 addr |= n & 0xff; 396 if (*p != '\0') 397 return IP_ANYADDR; 398 399 return ntohl(addr); 400 } 401