Home | History | Annotate | Line # | Download | only in libsa 
      1 /*	$NetBSD: udp.c,v 1.13 2019/03/31 20:08:45 christos 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 /* Caller must leave room for ethernet, ip and udp headers in front!! */
     66 ssize_t
     67 sendudp(struct iodesc *d, void *pkt, size_t len)
     68 {
     69 	ssize_t cc;
     70 	struct udphdr *uh;
     71 
     72 #ifdef NET_DEBUG
     73  	if (debug) {
     74 		printf("%s: d=%p called.\n", __func__, d);
     75 		if (d) {
     76 			printf("saddr: %s:%d",
     77 			    inet_ntoa(d->myip), ntohs(d->myport));
     78 			printf(" daddr: %s:%d\n",
     79 			    inet_ntoa(d->destip), ntohs(d->destport));
     80 		}
     81 	}
     82 #endif
     83 
     84 	uh = (struct udphdr *)pkt - 1;
     85 	len += sizeof(*uh);
     86 
     87 	(void)memset(uh, 0, sizeof(*uh));
     88 
     89 	uh->uh_sport = d->myport;
     90 	uh->uh_dport = d->destport;
     91 	uh->uh_ulen = htons(len);
     92 
     93 	cc = sendip(d, uh, len, IPPROTO_UDP);
     94 	if (cc == -1)
     95 		return -1;
     96 	if ((size_t)cc != len)
     97 		panic("%s: bad write (%zd != %zu)", __func__, cc, len);
     98 	return (cc - sizeof(*uh));
     99 }
    100 
    101 /*
    102  * Receive a UDP packet and validate it is for us.
    103  * Caller leaves room for the headers (Ether, IP, UDP)
    104  */
    105 ssize_t
    106 readudp(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
    107 {
    108 	ssize_t n;
    109 	struct udphdr *uh;
    110 
    111 	uh = (struct udphdr *)pkt - 1;
    112 	n = readip(d, uh, len + sizeof(*uh), tleft, IPPROTO_UDP);
    113 	if (n == -1 || (size_t)n < sizeof(*uh))
    114 		return -1;
    115 
    116 	if (uh->uh_dport != d->myport) {
    117 #ifdef NET_DEBUG
    118 		if (debug)
    119 			printf("%s: bad dport %d != %d\n", __func__,
    120 			    ntohs(d->myport), ntohs(uh->uh_dport));
    121 #endif
    122 		return -1;
    123 	}
    124 
    125 	if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
    126 #ifdef NET_DEBUG
    127 		if (debug)
    128 			printf("%s: bad udp len %d < %zu\n", __func__,
    129 				ntohs(uh->uh_ulen), sizeof(*uh));
    130 #endif
    131 		return -1;
    132 	}
    133 
    134 	n -= sizeof(*uh);
    135 	return n;
    136 }
    137