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net.c revision 1.1
      1 /*
      2  * Copyright (c) 1992 Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * This software was developed by the Computer Systems Engineering group
      6  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      7  * contributed to Berkeley.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed by the University of
     20  *	California, Lawrence Berkeley Laboratory and its contributors.
     21  * 4. Neither the name of the University nor the names of its contributors
     22  *    may be used to endorse or promote products derived from this software
     23  *    without specific prior written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     35  * SUCH DAMAGE.
     36  *
     37  * from @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
     38  */
     39 
     40 #include <sys/param.h>
     41 #include <sys/socket.h>
     42 
     43 #include <string.h>
     44 
     45 #include <net/if.h>
     46 
     47 #include <netinet/in.h>
     48 #include <netinet/if_ether.h>
     49 #include <netinet/in_systm.h>
     50 #include <netinet/ip.h>
     51 #include <netinet/ip_var.h>
     52 #include <netinet/udp.h>
     53 #include <netinet/udp_var.h>
     54 
     55 #include <errno.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