1 /* $OpenBSD: net.c,v 1.14 2014/07/13 15:31:20 mpi Exp $ */ 2 /* $NetBSD: net.c,v 1.14 1996/10/13 02:29:02 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1992 Regents of the University of California. 6 * All rights reserved. 7 * 8 * This software was developed by the Computer Systems Engineering group 9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 10 * contributed to Berkeley. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Lawrence Berkeley Laboratory and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL) 41 */ 42 43 #include <sys/param.h> 44 #include <sys/socket.h> 45 46 #include <net/if.h> 47 #include <netinet/in.h> 48 49 #include <netinet/in.h> 50 #include <netinet/if_ether.h> 51 #include <netinet/ip.h> 52 #include <netinet/ip_var.h> 53 #include <netinet/udp.h> 54 #include <netinet/udp_var.h> 55 56 #include "stand.h" 57 #include "net.h" 58 59 /* Caller must leave room for ethernet, ip and udp headers in front!! */ 60 ssize_t 61 sendudp(struct iodesc *d, void *pkt, size_t len) 62 { 63 ssize_t cc; 64 struct ip *ip; 65 struct udpiphdr *ui; 66 struct udphdr *uh; 67 u_char *ea; 68 struct ip tip; 69 70 #ifdef NET_DEBUG 71 if (debug) { 72 printf("sendudp: d=%x called.\n", (u_int)d); 73 if (d) { 74 printf("saddr: %s:%d", 75 inet_ntoa(d->myip), ntohs(d->myport)); 76 printf(" daddr: %s:%d\n", 77 inet_ntoa(d->destip), ntohs(d->destport)); 78 } 79 } 80 #endif 81 82 uh = (struct udphdr *)pkt - 1; 83 ip = (struct ip *)uh - 1; 84 len += sizeof(*ip) + sizeof(*uh); 85 86 bzero(ip, sizeof(*ip) + sizeof(*uh)); 87 88 ip->ip_v = IPVERSION; /* half-char */ 89 ip->ip_hl = sizeof(*ip) >> 2; /* half-char */ 90 ip->ip_len = htons(len); 91 ip->ip_p = IPPROTO_UDP; /* char */ 92 ip->ip_ttl = IP_TTL; /* char */ 93 ip->ip_src = d->myip; 94 ip->ip_dst = d->destip; 95 ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */ 96 97 uh->uh_sport = d->myport; 98 uh->uh_dport = d->destport; 99 uh->uh_ulen = htons(len - sizeof(*ip)); 100 101 /* Calculate checksum (must save and restore ip header) */ 102 tip = *ip; 103 ui = (struct udpiphdr *)ip; 104 bzero(ui->ui_x1, sizeof(ui->ui_x1)); 105 ui->ui_len = uh->uh_ulen; 106 uh->uh_sum = in_cksum(ui, len); 107 *ip = tip; 108 109 if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 || 110 netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask)) 111 ea = arpwhohas(d, ip->ip_dst); 112 else 113 ea = arpwhohas(d, gateip); 114 115 cc = sendether(d, ip, len, ea, ETHERTYPE_IP); 116 if (cc < 0) 117 return (-1); 118 if ((size_t)cc != len) 119 panic("sendudp: bad write (%d != %d)", cc, len); 120 return (cc - (sizeof(*ip) + sizeof(*uh))); 121 } 122 123 /* 124 * Receive a UDP packet and validate it is for us. 125 * Caller leaves room for the headers (Ether, IP, UDP) 126 */ 127 ssize_t 128 readudp(struct iodesc *d, void *pkt, size_t len, time_t tleft) 129 { 130 ssize_t n; 131 size_t hlen; 132 struct ip *ip; 133 struct udphdr *uh; 134 struct udpiphdr *ui; 135 struct ip tip; 136 u_int16_t etype; /* host order */ 137 138 #ifdef NET_DEBUG 139 if (debug) 140 printf("readudp: called\n"); 141 #endif 142 143 uh = (struct udphdr *)pkt - 1; 144 ip = (struct ip *)uh - 1; 145 146 n = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft, &etype); 147 if (n < 0 || (size_t)n < sizeof(*ip) + sizeof(*uh)) 148 return -1; 149 150 /* Ethernet address checks now in readether() */ 151 152 /* Need to respond to ARP requests. */ 153 if (etype == ETHERTYPE_ARP) { 154 struct arphdr *ah = (void *)ip; 155 if (ah->ar_op == htons(ARPOP_REQUEST)) { 156 /* Send ARP reply */ 157 arp_reply(d, ah); 158 } 159 return -1; 160 } 161 162 if (etype != ETHERTYPE_IP) { 163 #ifdef NET_DEBUG 164 if (debug) 165 printf("readudp: not IP. ether_type=%x\n", etype); 166 #endif 167 return -1; 168 } 169 170 /* Check ip header */ 171 if (ip->ip_v != IPVERSION || 172 ip->ip_p != IPPROTO_UDP) { /* half char */ 173 #ifdef NET_DEBUG 174 if (debug) 175 printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p); 176 #endif 177 return -1; 178 } 179 180 hlen = ip->ip_hl << 2; 181 if (hlen < sizeof(*ip) || 182 in_cksum(ip, hlen) != 0) { 183 #ifdef NET_DEBUG 184 if (debug) 185 printf("readudp: short hdr or bad cksum.\n"); 186 #endif 187 return -1; 188 } 189 NTOHS(ip->ip_len); 190 if (n < ip->ip_len) { 191 #ifdef NET_DEBUG 192 if (debug) 193 printf("readudp: bad length %d < %d.\n", n, ip->ip_len); 194 #endif 195 return -1; 196 } 197 if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) { 198 #ifdef NET_DEBUG 199 if (debug) { 200 printf("readudp: bad saddr %s != ", inet_ntoa(d->myip)); 201 printf("%s\n", inet_ntoa(ip->ip_dst)); 202 } 203 #endif 204 return -1; 205 } 206 207 /* If there were ip options, make them go away */ 208 if (hlen != sizeof(*ip)) { 209 bcopy(((u_char *)ip) + hlen, uh, len - hlen); 210 ip->ip_len = sizeof(*ip); 211 n -= hlen - sizeof(*ip); 212 } 213 if (uh->uh_dport != d->myport) { 214 #ifdef NET_DEBUG 215 if (debug) 216 printf("readudp: bad dport %d != %d\n", 217 d->myport, ntohs(uh->uh_dport)); 218 #endif 219 return -1; 220 } 221 222 if (uh->uh_sum) { 223 n = ntohs(uh->uh_ulen) + sizeof(*ip); 224 if (n > RECV_SIZE - ETHER_SIZE) { 225 printf("readudp: huge packet, udp len %ld\n", (long)n); 226 return -1; 227 } 228 229 /* Check checksum (must save and restore ip header) */ 230 tip = *ip; 231 ui = (struct udpiphdr *)ip; 232 bzero(ui->ui_x1, sizeof(ui->ui_x1)); 233 ui->ui_len = uh->uh_ulen; 234 if (in_cksum(ui, n) != 0) { 235 #ifdef NET_DEBUG 236 if (debug) 237 printf("readudp: bad cksum\n"); 238 #endif 239 *ip = tip; 240 return -1; 241 } 242 *ip = tip; 243 } 244 NTOHS(uh->uh_dport); 245 NTOHS(uh->uh_sport); 246 NTOHS(uh->uh_ulen); 247 if (uh->uh_ulen < sizeof(*uh)) { 248 #ifdef NET_DEBUG 249 if (debug) 250 printf("readudp: bad udp len %d < %d\n", 251 uh->uh_ulen, sizeof(*uh)); 252 #endif 253 return -1; 254 } 255 256 n -= sizeof(*ip) + sizeof(*uh); 257 return (n); 258 } 259 260 /* 261 * Send a packet and wait for a reply, with exponential backoff. 262 * 263 * The send routine must return the actual number of bytes written. 264 * 265 * The receive routine can indicate success by returning the number of 266 * bytes read; it can return 0 to indicate EOF; it can return -1 with a 267 * non-zero errno to indicate failure; finally, it can return -1 with a 268 * zero errno to indicate it isn't done yet. 269 */ 270 ssize_t 271 sendrecv(struct iodesc *d, ssize_t (*sproc)(struct iodesc *, void *, size_t), 272 void *sbuf, size_t ssize, 273 ssize_t (*rproc)(struct iodesc *, void *, size_t, time_t), 274 void *rbuf, size_t rsize) 275 { 276 ssize_t cc; 277 time_t t, tmo, tlast; 278 long tleft; 279 280 #ifdef NET_DEBUG 281 if (debug) 282 printf("sendrecv: called\n"); 283 #endif 284 285 tmo = MINTMO; 286 tlast = tleft = 0; 287 t = getsecs(); 288 for (;;) { 289 if (tleft <= 0) { 290 if (tmo >= MAXTMO) { 291 errno = ETIMEDOUT; 292 return -1; 293 } 294 cc = (*sproc)(d, sbuf, ssize); 295 if (cc < 0 || (size_t)cc < ssize) 296 panic("sendrecv: short write! (%d < %d)", 297 cc, ssize); 298 299 tleft = tmo; 300 tmo <<= 1; 301 if (tmo > MAXTMO) 302 tmo = MAXTMO; 303 tlast = t; 304 } 305 306 /* Try to get a packet and process it. */ 307 cc = (*rproc)(d, rbuf, rsize, tleft); 308 /* Return on data, EOF or real error. */ 309 if (cc != -1 || errno != 0) 310 return (cc); 311 312 /* Timed out or didn't get the packet we're waiting for */ 313 t = getsecs(); 314 tleft -= t - tlast; 315 tlast = t; 316 } 317 } 318 319 /* 320 * Like inet_addr() in the C library, but we only accept base-10. 321 * Return values are in network order. 322 */ 323 u_int32_t 324 inet_addr(char *cp) 325 { 326 u_long val; 327 int n; 328 char c; 329 u_int parts[4]; 330 u_int *pp = parts; 331 332 for (;;) { 333 /* 334 * Collect number up to ``.''. 335 * Values are specified as for C: 336 * 0x=hex, 0=octal, other=decimal. 337 */ 338 val = 0; 339 while ((c = *cp) != '\0') { 340 if (c >= '0' && c <= '9') { 341 val = (val * 10) + (c - '0'); 342 cp++; 343 continue; 344 } 345 break; 346 } 347 if (*cp == '.') { 348 /* 349 * Internet format: 350 * a.b.c.d 351 * a.b.c (with c treated as 16-bits) 352 * a.b (with b treated as 24 bits) 353 */ 354 if (pp >= parts + 3 || val > 0xff) 355 goto bad; 356 *pp++ = val, cp++; 357 } else 358 break; 359 } 360 /* 361 * Check for trailing characters. 362 */ 363 if (*cp != '\0') 364 goto bad; 365 366 /* 367 * Concoct the address according to 368 * the number of parts specified. 369 */ 370 n = pp - parts + 1; 371 switch (n) { 372 373 case 1: /* a -- 32 bits */ 374 break; 375 376 case 2: /* a.b -- 8.24 bits */ 377 if (val > 0xffffff) 378 goto bad; 379 val |= parts[0] << 24; 380 break; 381 382 case 3: /* a.b.c -- 8.8.16 bits */ 383 if (val > 0xffff) 384 goto bad; 385 val |= (parts[0] << 24) | (parts[1] << 16); 386 break; 387 388 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 389 if (val > 0xff) 390 goto bad; 391 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 392 break; 393 } 394 395 return (htonl(val)); 396 bad: 397 return (htonl(INADDR_NONE)); 398 } 399 400 char * 401 inet_ntoa(struct in_addr ia) 402 { 403 return (intoa(ia.s_addr)); 404 } 405 406 /* Similar to inet_ntoa() */ 407 char * 408 intoa(u_int32_t addr) 409 { 410 char *cp; 411 u_int byte; 412 int n; 413 static char buf[sizeof(".255.255.255.255")]; 414 415 NTOHL(addr); 416 cp = &buf[sizeof buf]; 417 *--cp = '\0'; 418 419 n = 4; 420 do { 421 byte = addr & 0xff; 422 *--cp = byte % 10 + '0'; 423 byte /= 10; 424 if (byte > 0) { 425 *--cp = byte % 10 + '0'; 426 byte /= 10; 427 if (byte > 0) 428 *--cp = byte + '0'; 429 } 430 *--cp = '.'; 431 addr >>= 8; 432 } while (--n > 0); 433 434 return (cp+1); 435 } 436 437 static char * 438 number(char *s, int *n) 439 { 440 for (*n = 0; isdigit(*s); s++) 441 *n = (*n * 10) + *s - '0'; 442 return s; 443 } 444 445 u_int32_t 446 ip_convertaddr(char *p) 447 { 448 #define IP_ANYADDR 0 449 u_int32_t addr = 0, n; 450 451 if (p == (char *)0 || *p == '\0') 452 return IP_ANYADDR; 453 p = number(p, &n); 454 addr |= (n << 24) & 0xff000000; 455 if (*p == '\0' || *p++ != '.') 456 return IP_ANYADDR; 457 p = number(p, &n); 458 addr |= (n << 16) & 0xff0000; 459 if (*p == '\0' || *p++ != '.') 460 return IP_ANYADDR; 461 p = number(p, &n); 462 addr |= (n << 8) & 0xff00; 463 if (*p == '\0' || *p++ != '.') 464 return IP_ANYADDR; 465 p = number(p, &n); 466 addr |= n & 0xff; 467 if (*p != '\0') 468 return IP_ANYADDR; 469 470 return htonl(addr); 471 } 472