xref: /netbsd-src/usr.sbin/mopd/common/loop-bsd.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: loop-bsd.c,v 1.10 2009/10/20 00:51:13 snj Exp $	*/
2 
3 /*
4  * Copyright (c) 1993-95 Mats O Jansson.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 #ifndef lint
29 __RCSID("$NetBSD: loop-bsd.c,v 1.10 2009/10/20 00:51:13 snj Exp $");
30 #endif
31 
32 #include <errno.h>
33 #include <stdlib.h>
34 #include <strings.h>
35 #include <unistd.h>
36 #if defined(__bsdi__) || defined(__FreeBSD__) || defined(__NetBSD__)
37 #include <sys/time.h>
38 #endif
39 #include <net/bpf.h>
40 #include <sys/ioctl.h>
41 #include <sys/poll.h>
42 #include <assert.h>
43 
44 #include "os.h"
45 #include "common.h"
46 #include "device.h"
47 #include "mopdef.h"
48 #include "log.h"
49 
50 int
51 mopOpenRC(p, trans)
52 	struct if_info *p;
53 	int	trans;
54 {
55 #ifndef NORC
56 	return (*(p->iopen))(p->if_name,
57 			     O_RDWR,
58 			     MOP_K_PROTO_RC,
59 			     trans);
60 #else
61 	return -1;
62 #endif
63 }
64 
65 int
66 mopOpenDL(p, trans)
67 	struct if_info *p;
68 	int	trans;
69 {
70 #ifndef NODL
71 	return (*(p->iopen))(p->if_name,
72 			     O_RDWR,
73 			     MOP_K_PROTO_DL,
74 			     trans);
75 #else
76 	return -1;
77 #endif
78 }
79 
80 void
81 mopReadRC()
82 {
83 }
84 
85 void
86 mopReadDL()
87 {
88 }
89 
90 /*
91  * The list of all interfaces that are being listened to.  loop()
92  * "polls" on the descriptors in this list.
93  */
94 struct if_info *iflist;
95 
96 void   mopProcess    __P((struct if_info *, u_char *));
97 
98 /*
99  * Loop indefinitely listening for MOP requests on the
100  * interfaces in 'iflist'.
101  */
102 void
103 Loop()
104 {
105 	u_char *buf, *bp, *ep;
106 	int     cc, n, m;
107 	struct	pollfd *set;
108 	int     bufsize;
109 	struct	if_info *ii;
110 
111 	if (iflist == 0)
112 		mopLogErrX("no interfaces");
113 	if (iflist->fd != -1) {
114 		if (ioctl(iflist->fd, BIOCGBLEN, (caddr_t) & bufsize) < 0)
115 			mopLogErr("BIOCGBLEN");
116 	} else
117 		mopLogErrX("cannot get buffer size");
118 	buf = (u_char *) malloc((unsigned) bufsize);
119 	if (buf == 0)
120 		mopLogErr("malloc");
121 	/*
122          * Find the highest numbered file descriptor for poll().
123          * Initialize the set of descriptors to listen to.
124          */
125 	for (ii = iflist, n = 0; ii; ii = ii->next, n++)
126 		;
127 	set = malloc(n * sizeof(*set));
128 	for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
129 		assert(ii->fd != -1);
130 		set[m].fd = ii->fd;
131 		set[m].events = POLLIN;
132 	}
133 	for (;;) {
134 		if (poll(set, n, INFTIM) < 0)
135 			mopLogErr("poll");
136 		for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
137 			if (!(set[m].revents & POLLIN))
138 				continue;
139 	again:
140 			cc = read(ii->fd, (char *) buf, bufsize);
141 			/* Don't choke when we get ptraced */
142 			if (cc < 0 && errno == EINTR)
143 				goto again;
144 			/* Due to a SunOS bug, after 2^31 bytes, the file
145 			 * offset overflows and read fails with EINVAL.  The
146 			 * lseek() to 0 will fix things. */
147 			if (cc < 0) {
148 				if (errno == EINVAL &&
149 				    (lseek(ii->fd, 0, SEEK_CUR) + bufsize) < 0) {
150 					(void) lseek(ii->fd, 0, 0);
151 					goto again;
152 				}
153 				mopLogErr("read");
154 			}
155 			/* Loop through the packet(s) */
156 #define bhp ((struct bpf_hdr *)bp)
157 			bp = buf;
158 			ep = bp + cc;
159 			while (bp < ep) {
160 				int caplen, hdrlen;
161 
162 				caplen = bhp->bh_caplen;
163 				hdrlen = bhp->bh_hdrlen;
164 				mopProcess(ii, bp + hdrlen);
165 				bp += BPF_WORDALIGN(hdrlen + caplen);
166 			}
167 		}
168 	}
169 }
170