Home | History | Annotate | Line # | Download | only in libsa
net.c revision 1.21 
      1 /*	$NetBSD: net.c,v 1.21 1999/02/11 09:10:44 pk 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 #ifdef _STANDALONE
     46 #include <lib/libkern/libkern.h>
     47 #else
     48 #include <string.h>
     49 #endif
     50 
     51 #include <net/if.h>
     52 #include <net/if_ether.h>
     53 
     54 #include <netinet/in.h>
     55 #include <netinet/in_systm.h>
     56 #include <netinet/ip.h>
     57 #include <netinet/ip_var.h>
     58 #include <netinet/udp.h>
     59 #include <netinet/udp_var.h>
     60 
     61 #include "stand.h"
     62 #include "net.h"
     63 
     64 
     65 static char	*number __P((char *, int *));
     66 
     67 /* Caller must leave room for ethernet, ip and udp headers in front!! */
     68 ssize_t
     69 sendudp(d, pkt, len)
     70 	register struct iodesc *d;
     71 	register void *pkt;
     72 	register size_t len;
     73 {
     74 	register ssize_t cc;
     75 	register struct ip *ip;
     76 	register struct udphdr *uh;
     77 	register u_char *ea;
     78 
     79 #ifdef NET_DEBUG
     80  	if (debug) {
     81 		printf("sendudp: d=%lx called.\n", (long)d);
     82 		if (d) {
     83 			printf("saddr: %s:%d",
     84 			    inet_ntoa(d->myip), ntohs(d->myport));
     85 			printf(" daddr: %s:%d\n",
     86 			    inet_ntoa(d->destip), ntohs(d->destport));
     87 		}
     88 	}
     89 #endif
     90 
     91 	uh = (struct udphdr *)pkt - 1;
     92 	ip = (struct ip *)uh - 1;
     93 	len += sizeof(*ip) + sizeof(*uh);
     94 
     95 	bzero(ip, sizeof(*ip) + sizeof(*uh));
     96 
     97 	ip->ip_v = IPVERSION;			/* half-char */
     98 	ip->ip_hl = sizeof(*ip) >> 2;		/* half-char */
     99 	ip->ip_len = htons(len);
    100 	ip->ip_p = IPPROTO_UDP;			/* char */
    101 	ip->ip_ttl = IP_TTL;			/* char */
    102 	ip->ip_src = d->myip;
    103 	ip->ip_dst = d->destip;
    104 	ip->ip_sum = in_cksum(ip, sizeof(*ip));	 /* short, but special */
    105 
    106 	uh->uh_sport = d->myport;
    107 	uh->uh_dport = d->destport;
    108 	uh->uh_ulen = htons(len - sizeof(*ip));
    109 
    110 #ifndef UDP_NO_CKSUM
    111 	{
    112 		register struct udpiphdr *ui;
    113 		struct ip tip;
    114 
    115 		/* Calculate checksum (must save and restore ip header) */
    116 		tip = *ip;
    117 		ui = (struct udpiphdr *)ip;
    118 		bzero(ui->ui_x1, sizeof(ui->ui_x1));
    119 		ui->ui_len = uh->uh_ulen;
    120 		uh->uh_sum = in_cksum(ui, len);
    121 		*ip = tip;
    122 	}
    123 #endif
    124 
    125 	if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
    126 	    netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask))
    127 		ea = arpwhohas(d, ip->ip_dst);
    128 	else
    129 		ea = arpwhohas(d, gateip);
    130 
    131 	cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
    132 	if (cc == -1)
    133 		return (-1);
    134 	if (cc != len)
    135 		panic("sendudp: bad write (%d != %d)", cc, len);
    136 	return (cc - (sizeof(*ip) + sizeof(*uh)));
    137 }
    138 
    139 /*
    140  * Receive a UDP packet and validate it is for us.
    141  * Caller leaves room for the headers (Ether, IP, UDP)
    142  */
    143 ssize_t
    144 readudp(d, pkt, len, tleft)
    145 	register struct iodesc *d;
    146 	register void *pkt;
    147 	register size_t len;
    148 	time_t tleft;
    149 {
    150 	register ssize_t n;
    151 	register size_t hlen;
    152 	register struct ip *ip;
    153 	register struct udphdr *uh;
    154 	u_int16_t etype;	/* host order */
    155 
    156 #ifdef NET_DEBUG
    157 	if (debug)
    158 		printf("readudp: called\n");
    159 #endif
    160 
    161 	uh = (struct udphdr *)pkt - 1;
    162 	ip = (struct ip *)uh - 1;
    163 
    164 	n = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft, &etype);
    165 	if (n == -1 || n < sizeof(*ip) + sizeof(*uh))
    166 		return -1;
    167 
    168 	/* Ethernet address checks now in readether() */
    169 
    170 	/* Need to respond to ARP requests. */
    171 	if (etype == ETHERTYPE_ARP) {
    172 		struct arphdr *ah = (void *)ip;
    173 		if (ah->ar_op == htons(ARPOP_REQUEST)) {
    174 			/* Send ARP reply */
    175 			arp_reply(d, ah);
    176 		}
    177 		return -1;
    178 	}
    179 
    180 	if (etype != ETHERTYPE_IP) {
    181 #ifdef NET_DEBUG
    182 		if (debug)
    183 			printf("readudp: not IP. ether_type=%x\n", etype);
    184 #endif
    185 		return -1;
    186 	}
    187 
    188 	/* Check ip header */
    189 	if (ip->ip_v != IPVERSION ||
    190 	    ip->ip_p != IPPROTO_UDP) {	/* half char */
    191 #ifdef NET_DEBUG
    192 		if (debug)
    193 			printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
    194 #endif
    195 		return -1;
    196 	}
    197 
    198 	hlen = ip->ip_hl << 2;
    199 	if (hlen < sizeof(*ip) ||
    200 	    in_cksum(ip, hlen) != 0) {
    201 #ifdef NET_DEBUG
    202 		if (debug)
    203 			printf("readudp: short hdr or bad cksum.\n");
    204 #endif
    205 		return -1;
    206 	}
    207 	if (n < ntohs(ip->ip_len)) {
    208 #ifdef NET_DEBUG
    209 		if (debug)
    210 			printf("readudp: bad length %d < %d.\n",
    211 			       (int)n, ntohs(ip->ip_len));
    212 #endif
    213 		return -1;
    214 	}
    215 	if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) {
    216 #ifdef NET_DEBUG
    217 		if (debug) {
    218 			printf("readudp: bad saddr %s != ", inet_ntoa(d->myip));
    219 			printf("%s\n", inet_ntoa(ip->ip_dst));
    220 		}
    221 #endif
    222 		return -1;
    223 	}
    224 
    225 	/* If there were ip options, make them go away */
    226 	if (hlen != sizeof(*ip)) {
    227 		bcopy(((u_char *)ip) + hlen, uh, len - hlen);
    228 		ip->ip_len = htons(sizeof(*ip));
    229 		n -= hlen - sizeof(*ip);
    230 	}
    231 	if (uh->uh_dport != d->myport) {
    232 #ifdef NET_DEBUG
    233 		if (debug)
    234 			printf("readudp: bad dport %d != %d\n",
    235 				d->myport, ntohs(uh->uh_dport));
    236 #endif
    237 		return -1;
    238 	}
    239 
    240 #ifndef UDP_NO_CKSUM
    241 	if (uh->uh_sum) {
    242 		register struct udpiphdr *ui;
    243 		struct ip tip;
    244 
    245 		n = ntohs(uh->uh_ulen) + sizeof(*ip);
    246 		if (n > RECV_SIZE - ETHER_SIZE) {
    247 			printf("readudp: huge packet, udp len %d\n", (int)n);
    248 			return -1;
    249 		}
    250 
    251 		/* Check checksum (must save and restore ip header) */
    252 		tip = *ip;
    253 		ui = (struct udpiphdr *)ip;
    254 		bzero(ui->ui_x1, sizeof(ui->ui_x1));
    255 		ui->ui_len = uh->uh_ulen;
    256 		if (in_cksum(ui, n) != 0) {
    257 #ifdef NET_DEBUG
    258 			if (debug)
    259 				printf("readudp: bad cksum\n");
    260 #endif
    261 			*ip = tip;
    262 			return -1;
    263 		}
    264 		*ip = tip;
    265 	}
    266 #endif
    267 	if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
    268 #ifdef NET_DEBUG
    269 		if (debug)
    270 			printf("readudp: bad udp len %d < %d\n",
    271 				ntohs(uh->uh_ulen), (int)sizeof(*uh));
    272 #endif
    273 		return -1;
    274 	}
    275 
    276 	n -= sizeof(*ip) + sizeof(*uh);
    277 	return (n);
    278 }
    279 
    280 /*
    281  * Send a packet and wait for a reply, with exponential backoff.
    282  *
    283  * The send routine must return the actual number of bytes written,
    284  * or -1 on error.
    285  *
    286  * The receive routine can indicate success by returning the number of
    287  * bytes read; it can return 0 to indicate EOF; it can return -1 with a
    288  * non-zero errno to indicate failure; finally, it can return -1 with a
    289  * zero errno to indicate it isn't done yet.
    290  */
    291 ssize_t
    292 sendrecv(d, sproc, sbuf, ssize, rproc, rbuf, rsize)
    293 	register struct iodesc *d;
    294 	register ssize_t (*sproc)(struct iodesc *, void *, size_t);
    295 	register void *sbuf;
    296 	register size_t ssize;
    297 	register ssize_t (*rproc)(struct iodesc *, void *, size_t, time_t);
    298 	register void *rbuf;
    299 	register size_t rsize;
    300 {
    301 	register ssize_t cc;
    302 	register time_t t, tmo, tlast;
    303 	long tleft;
    304 
    305 #ifdef NET_DEBUG
    306 	if (debug)
    307 		printf("sendrecv: called\n");
    308 #endif
    309 
    310 	tmo = MINTMO;
    311 	tlast = tleft = 0;
    312 	t = getsecs();
    313 	for (;;) {
    314 		if (tleft <= 0) {
    315 			if (tmo >= MAXTMO) {
    316 				errno = ETIMEDOUT;
    317 				return -1;
    318 			}
    319 			cc = (*sproc)(d, sbuf, ssize);
    320 			if (cc != -1 && cc < ssize)
    321 				panic("sendrecv: short write! (%d < %d)",
    322 				    cc, ssize);
    323 
    324 			tleft = tmo;
    325 			tmo <<= 1;
    326 			if (tmo > MAXTMO)
    327 				tmo = MAXTMO;
    328 
    329 			if (cc == -1) {
    330 				/* Error on transmit; wait before retrying */
    331 				while ((getsecs() - t) < tmo);
    332 				tleft = 0;
    333 				continue;
    334 			}
    335 
    336 			tlast = t;
    337 		}
    338 
    339 		/* Try to get a packet and process it. */
    340 		cc = (*rproc)(d, rbuf, rsize, tleft);
    341 		/* Return on data, EOF or real error. */
    342 		if (cc != -1 || errno != 0)
    343 			return (cc);
    344 
    345 		/* Timed out or didn't get the packet we're waiting for */
    346 		t = getsecs();
    347 		tleft -= t - tlast;
    348 		tlast = t;
    349 	}
    350 }
    351 
    352 /*
    353  * Like inet_addr() in the C library, but we only accept base-10.
    354  * Return values are in network order.
    355  */
    356 n_long
    357 inet_addr(cp)
    358 	char *cp;
    359 {
    360 	register u_long val;
    361 	register int n;
    362 	register char c;
    363 	u_int parts[4];
    364 	register u_int *pp = parts;
    365 
    366 	for (;;) {
    367 		/*
    368 		 * Collect number up to ``.''.
    369 		 * Values are specified as for C:
    370 		 * 0x=hex, 0=octal, other=decimal.
    371 		 */
    372 		val = 0;
    373 		while ((c = *cp) != '\0') {
    374 			if (c >= '0' && c <= '9') {
    375 				val = (val * 10) + (c - '0');
    376 				cp++;
    377 				continue;
    378 			}
    379 			break;
    380 		}
    381 		if (*cp == '.') {
    382 			/*
    383 			 * Internet format:
    384 			 *	a.b.c.d
    385 			 *	a.b.c	(with c treated as 16-bits)
    386 			 *	a.b	(with b treated as 24 bits)
    387 			 */
    388 			if (pp >= parts + 3 || val > 0xff)
    389 				goto bad;
    390 			*pp++ = val, cp++;
    391 		} else
    392 			break;
    393 	}
    394 	/*
    395 	 * Check for trailing characters.
    396 	 */
    397 	if (*cp != '\0')
    398 		goto bad;
    399 
    400 	/*
    401 	 * Concoct the address according to
    402 	 * the number of parts specified.
    403 	 */
    404 	n = pp - parts + 1;
    405 	switch (n) {
    406 
    407 	case 1:				/* a -- 32 bits */
    408 		break;
    409 
    410 	case 2:				/* a.b -- 8.24 bits */
    411 		if (val > 0xffffff)
    412 			goto bad;
    413 		val |= parts[0] << 24;
    414 		break;
    415 
    416 	case 3:				/* a.b.c -- 8.8.16 bits */
    417 		if (val > 0xffff)
    418 			goto bad;
    419 		val |= (parts[0] << 24) | (parts[1] << 16);
    420 		break;
    421 
    422 	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
    423 		if (val > 0xff)
    424 			goto bad;
    425 		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
    426 		break;
    427 	}
    428 
    429 	return (htonl(val));
    430  bad:
    431 	return (htonl(INADDR_NONE));
    432 }
    433 
    434 char *
    435 inet_ntoa(ia)
    436 	struct in_addr ia;
    437 {
    438 	return (intoa(ia.s_addr));
    439 }
    440 
    441 /* Similar to inet_ntoa() */
    442 char *
    443 intoa(addr)
    444 	register n_long addr;
    445 {
    446 	register char *cp;
    447 	register u_int byte;
    448 	register int n;
    449 	static char buf[17];	/* strlen(".255.255.255.255") + 1 */
    450 
    451 	NTOHL(addr);
    452 	cp = &buf[sizeof buf];
    453 	*--cp = '\0';
    454 
    455 	n = 4;
    456 	do {
    457 		byte = addr & 0xff;
    458 		*--cp = byte % 10 + '0';
    459 		byte /= 10;
    460 		if (byte > 0) {
    461 			*--cp = byte % 10 + '0';
    462 			byte /= 10;
    463 			if (byte > 0)
    464 				*--cp = byte + '0';
    465 		}
    466 		*--cp = '.';
    467 		addr >>= 8;
    468 	} while (--n > 0);
    469 
    470 	return (cp+1);
    471 }
    472 
    473 
    474 static char *
    475 number(s, n)
    476 	char *s;
    477 	int *n;
    478 {
    479 	for (*n = 0; isdigit(*s); s++)
    480 		*n = (*n * 10) + *s - '0';
    481 	return s;
    482 }
    483 
    484 n_long
    485 ip_convertaddr(p)
    486 	char *p;
    487 {
    488 #define IP_ANYADDR	0
    489 	n_long addr = 0, n;
    490 
    491 	if (p == (char *)0 || *p == '\0')
    492 		return IP_ANYADDR;
    493 	p = number(p, &n);
    494 	addr |= (n << 24) & 0xff000000;
    495 	if (*p == '\0' || *p++ != '.')
    496 		return IP_ANYADDR;
    497 	p = number(p, &n);
    498 	addr |= (n << 16) & 0xff0000;
    499 	if (*p == '\0' || *p++ != '.')
    500 		return IP_ANYADDR;
    501 	p = number(p, &n);
    502 	addr |= (n << 8) & 0xff00;
    503 	if (*p == '\0' || *p++ != '.')
    504 		return IP_ANYADDR;
    505 	p = number(p, &n);
    506 	addr |= n & 0xff;
    507 	if (*p != '\0')
    508 		return IP_ANYADDR;
    509 
    510 	return htonl(addr);
    511 }
    512