1 /* $NetBSD: net.c,v 1.3 1994/10/26 05:44:52 cgd 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 int 65 sendudp(d, buf, len) 66 register struct iodesc *d; 67 register void *buf; 68 register int len; 69 { 70 register int 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 uh = ((struct udphdr *)buf) - 1; 89 ip = ((struct ip *)uh) - 1; 90 len += sizeof(*ip) + sizeof(*uh); 91 92 bzero(ip, sizeof(*ip) + sizeof(*uh)); 93 94 ip->ip_v = IPVERSION; /* half-char */ 95 ip->ip_hl = sizeof(*ip) >> 2; /* half-char */ 96 ip->ip_len = htons(len); 97 ip->ip_p = IPPROTO_UDP; /* char */ 98 ip->ip_ttl = IP_TTL; /* char */ 99 ip->ip_src.s_addr = htonl(d->myip); 100 ip->ip_dst.s_addr = htonl(d->destip); 101 ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */ 102 103 uh->uh_sport = htons(d->myport); 104 uh->uh_dport = htons(d->destport); 105 uh->uh_ulen = htons(len - sizeof(*ip)); 106 107 /* Calculate checksum (must save and restore ip header) */ 108 tip = *ip; 109 ui = (struct udpiphdr *)ip; 110 ui->ui_next = 0; 111 ui->ui_prev = 0; 112 ui->ui_x1 = 0; 113 ui->ui_len = uh->uh_ulen; 114 uh->uh_sum = in_cksum(ui, len); 115 *ip = tip; 116 117 if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 || 118 mask == 0 || SAMENET(ip->ip_src.s_addr, ip->ip_dst.s_addr, mask)) 119 ea = arpwhohas(d, ip->ip_dst.s_addr); 120 else 121 ea = arpwhohas(d, htonl(gateip)); 122 123 cc = sendether(d, ip, len, ea, ETHERTYPE_IP); 124 if (cc < 0) 125 return (cc); 126 if (cc != len) 127 panic("sendudp: bad write (%d != %d)", cc, len); 128 return (cc - (sizeof(*ip) + sizeof(*uh))); 129 } 130 131 /* Check that packet is a valid udp packet for us */ 132 void * 133 checkudp(d, pkt, lenp) 134 register struct iodesc *d; 135 register void *pkt; 136 register int *lenp; 137 { 138 register int hlen, len; 139 register struct ether_header *eh; 140 register struct ip *ip; 141 register struct udphdr *uh; 142 register struct udpiphdr *ui; 143 struct ip tip; 144 145 #ifdef NET_DEBUG 146 if (debug) 147 printf("checkudp: called\n"); 148 #endif 149 eh = pkt; 150 ip = (struct ip *)(eh + 1); 151 uh = (struct udphdr *)(ip + 1); 152 153 /* Must be to us */ 154 if (bcmp(d->myea, eh->ether_dhost, 6) != 0 && /* by byte */ 155 bcmp(bcea, eh->ether_dhost, 6) != 0) { /* by byte */ 156 #ifdef NET_DEBUG 157 if (debug) 158 printf("checkudp: not ours. myea=%s bcea=%s\n", 159 ether_sprintf(d->myea), ether_sprintf(bcea)); 160 #endif 161 return (NULL); 162 } 163 164 /* And ip */ 165 if (ntohs(eh->ether_type) != ETHERTYPE_IP) { 166 #ifdef NET_DEBUG 167 if (debug) 168 printf("checkudp: not IP. ether_type=%x\n", eh->ether_type); 169 #endif 170 return (NULL); 171 } 172 173 /* Check ip header */ 174 if (ip->ip_v != IPVERSION || ip->ip_p != IPPROTO_UDP) { /* half char */ 175 #ifdef NET_DEBUG 176 if (debug) 177 printf("checkudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p); 178 #endif 179 return (NULL); 180 } 181 182 hlen = ip->ip_hl << 2; 183 if (hlen < sizeof(*ip) || in_cksum(ip, hlen) != 0) { 184 #ifdef NET_DEBUG 185 if (debug) 186 printf("checkudp: short hdr or bad cksum.\n"); 187 #endif 188 return (NULL); 189 } 190 NTOHS(ip->ip_len); 191 if (*lenp - sizeof(*eh) < ip->ip_len) { 192 #ifdef NET_DEBUG 193 if (debug) 194 printf("checkudp: bad length %d < %d.\n", 195 *lenp - sizeof(*eh), ip->ip_len); 196 #endif 197 return (NULL); 198 } 199 if (d->myip && ntohl(ip->ip_dst.s_addr) != d->myip) { 200 #ifdef NET_DEBUG 201 if (debug) { 202 printf("checkudp: bad saddr %s != ", 203 intoa(d->myip)); 204 printf("%s\n", 205 intoa(ntohl(ip->ip_dst.s_addr))); 206 } 207 #endif 208 return (NULL); 209 } 210 211 /* If there were ip options, make them go away */ 212 if (hlen != sizeof(*ip)) { 213 bcopy(((u_char *)ip) + hlen, uh, 214 *lenp - (sizeof(*eh) + hlen)); 215 ip->ip_len = sizeof(*ip); 216 *lenp -= hlen - sizeof(*ip); 217 } 218 if (ntohs(uh->uh_dport) != d->myport) { 219 #ifdef NET_DEBUG 220 if (debug) 221 printf("checkudp: bad dport %d != %d\n", 222 d->myport, ntohs(uh->uh_dport)); 223 #endif 224 return (NULL); 225 } 226 227 if (uh->uh_sum) { 228 len = ntohs(uh->uh_ulen); 229 if (len > RECV_SIZE - (sizeof(*eh) + sizeof(*ip))) { 230 printf("checkudp: huge packet, udp len %d\n", len); 231 return (NULL); 232 } 233 234 /* Check checksum (must save and restore ip header) */ 235 tip = *ip; 236 ui = (struct udpiphdr *)ip; 237 ui->ui_next = 0; 238 ui->ui_prev = 0; 239 ui->ui_x1 = 0; 240 ui->ui_len = uh->uh_ulen; 241 if (in_cksum(ui, len + sizeof(*ip)) != 0) { 242 #ifdef NET_DEBUG 243 if (debug) 244 printf("checkudp: bad cksum\n"); 245 #endif 246 *ip = tip; 247 return (NULL); 248 } 249 *ip = tip; 250 } 251 NTOHS(uh->uh_dport); 252 NTOHS(uh->uh_sport); 253 NTOHS(uh->uh_ulen); 254 if (uh->uh_ulen < sizeof(*uh)) { 255 #ifdef NET_DEBUG 256 if (debug) 257 printf("checkudp: bad udp len %d < %d\n", 258 uh->uh_ulen, sizeof(*uh)); 259 #endif 260 return (NULL); 261 } 262 *lenp -= sizeof(*eh) + sizeof(*ip) + sizeof(*uh); 263 return (uh + 1); 264 } 265 266 /* 267 * Send a packet and wait for a reply, with exponential backoff. 268 * 269 * The send routine must return the actual number of bytes written. 270 * 271 * The receive routine can indicate success by returning the number of 272 * bytes read; it can return 0 to indicate EOF; it can return -1 with a 273 * non-zero errno to indicate failure; finally, it can return -1 with a 274 * zero errno to indicate it isn't done yet. 275 */ 276 int 277 sendrecv(d, sproc, sbuf, ssize, rproc, rbuf, rsize) 278 register struct iodesc *d; 279 register int (*sproc)(struct iodesc *, void *, int); 280 register void *sbuf; 281 register int ssize; 282 register int (*rproc)(struct iodesc *, void *, int); 283 register void *rbuf; 284 register int rsize; 285 { 286 register int cc; 287 register time_t t, tmo, tlast, tleft; 288 289 #ifdef NET_DEBUG 290 if (debug) 291 printf("sendrecv: called\n"); 292 #endif 293 tmo = MINTMO; 294 tlast = tleft = 0; 295 t = getsecs(); 296 for (;;) { 297 if (tleft <= 0) { 298 cc = (*sproc)(d, sbuf, ssize); 299 if (cc < ssize) 300 panic("sendrecv: short write! (%d < %d)", 301 cc, ssize); 302 303 tleft = tmo; 304 tmo <<= 1; 305 if (tmo > MAXTMO) 306 tmo = MAXTMO; 307 tlast = t; 308 } 309 310 cc = netif_get(d, rbuf, rsize, tleft); 311 if (cc >= 0) { 312 /* Got a packet, process it */ 313 cc = (*rproc)(d, rbuf, cc); 314 /* Return on data, EOF or real error */ 315 if (cc >= 0 || errno != 0) 316 return (cc); 317 } 318 /* Timed out or didn't get the packet we're waiting for */ 319 t = getsecs(); 320 tleft -= t - tlast; 321 tlast = t; 322 } 323 } 324 325 /* Similar to inet_ntoa() */ 326 char * 327 intoa(addr) 328 n_long addr; 329 { 330 register char *cp; 331 register u_int byte; 332 register int n; 333 static char buf[17]; /* strlen(".255.255.255.255") + 1 */ 334 335 cp = &buf[sizeof buf]; 336 *--cp = '\0'; 337 338 n = 4; 339 do { 340 byte = addr & 0xff; 341 *--cp = byte % 10 + '0'; 342 byte /= 10; 343 if (byte > 0) { 344 *--cp = byte % 10 + '0'; 345 byte /= 10; 346 if (byte > 0) 347 *--cp = byte + '0'; 348 } 349 *--cp = '.'; 350 addr >>= 8; 351 } while (--n > 0); 352 353 return (cp+1); 354 } 355 356 static char * 357 number(s, n) 358 char *s; 359 int *n; 360 { 361 for (*n = 0; isdigit(*s); s++) 362 *n = (*n * 10) + *s - '0'; 363 return s; 364 } 365 366 n_long 367 ip_convertaddr(p) 368 char *p; 369 { 370 #define IP_ANYADDR 0 371 n_long addr = 0, n; 372 373 if (p == (char *)0 || *p == '\0') 374 return IP_ANYADDR; 375 p = number(p, &n); 376 addr |= (n << 24) & 0xff000000; 377 if (*p == '\0' || *p++ != '.') 378 return IP_ANYADDR; 379 p = number(p, &n); 380 addr |= (n << 16) & 0xff0000; 381 if (*p == '\0' || *p++ != '.') 382 return IP_ANYADDR; 383 p = number(p, &n); 384 addr |= (n << 8) & 0xff00; 385 if (*p == '\0' || *p++ != '.') 386 return IP_ANYADDR; 387 p = number(p, &n); 388 addr |= n & 0xff; 389 if (*p != '\0') 390 return IP_ANYADDR; 391 392 return ntohl(addr); 393 } 394