xref: /netbsd-src/usr.sbin/mopd/common/loop-bsd.c (revision 14fa6887c593aea58abfdfa86a3a0f6c866991cd)
1 /*	$NetBSD: loop-bsd.c,v 1.13 2020/04/22 23:55:29 joerg 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 "port.h"
28 #ifndef lint
29 __RCSID("$NetBSD: loop-bsd.c,v 1.13 2020/04/22 23:55:29 joerg 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
mopOpenRC(struct if_info * p,int trans)51 mopOpenRC(struct if_info *p, int trans)
52 {
53 #ifndef NORC
54 	return (*(p->iopen))(p->if_name,
55 			     O_RDWR,
56 			     MOP_K_PROTO_RC,
57 			     trans);
58 #else
59 	return -1;
60 #endif
61 }
62 
63 int
mopOpenDL(struct if_info * p,int trans)64 mopOpenDL(struct if_info *p, int trans)
65 {
66 #ifndef NODL
67 	return (*(p->iopen))(p->if_name,
68 			     O_RDWR,
69 			     MOP_K_PROTO_DL,
70 			     trans);
71 #else
72 	return -1;
73 #endif
74 }
75 
76 void
mopReadRC(void)77 mopReadRC(void)
78 {
79 }
80 
81 void
mopReadDL(void)82 mopReadDL(void)
83 {
84 }
85 
86 /*
87  * The list of all interfaces that are being listened to.  loop()
88  * "polls" on the descriptors in this list.
89  */
90 extern struct if_info *iflist;
91 
92 void   mopProcess(struct if_info *, u_char *);
93 
94 /*
95  * Loop indefinitely listening for MOP requests on the
96  * interfaces in 'iflist'.
97  */
98 void
Loop(void)99 Loop(void)
100 {
101 	u_char *buf, *bp, *ep;
102 	int     cc, n, m;
103 	struct	pollfd *set;
104 	int     bufsize;
105 	struct	if_info *ii;
106 
107 	if (iflist == 0)
108 		mopLogErrX("no interfaces");
109 	if (iflist->fd != -1) {
110 		if (ioctl(iflist->fd, BIOCGBLEN, (caddr_t) & bufsize) < 0)
111 			mopLogErr("BIOCGBLEN");
112 	} else
113 		mopLogErrX("cannot get buffer size");
114 	buf = (u_char *) malloc((unsigned) bufsize);
115 	if (buf == 0)
116 		mopLogErr("malloc");
117 	/*
118          * Find the highest numbered file descriptor for poll().
119          * Initialize the set of descriptors to listen to.
120          */
121 	for (ii = iflist, n = 0; ii; ii = ii->next, n++)
122 		;
123 	set = malloc(n * sizeof(*set));
124 	for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
125 		assert(ii->fd != -1);
126 		set[m].fd = ii->fd;
127 		set[m].events = POLLIN;
128 	}
129 	for (;;) {
130 		if (poll(set, n, INFTIM) < 0)
131 			mopLogErr("poll");
132 		for (ii = iflist, m = 0; ii; ii = ii->next, m++) {
133 			if (!(set[m].revents & POLLIN))
134 				continue;
135 	again:
136 			cc = read(ii->fd, (char *) buf, bufsize);
137 			/* Don't choke when we get ptraced */
138 			if (cc < 0 && errno == EINTR)
139 				goto again;
140 			/* Due to a SunOS bug, after 2^31 bytes, the file
141 			 * offset overflows and read fails with EINVAL.  The
142 			 * lseek() to 0 will fix things. */
143 			if (cc < 0) {
144 				if (errno == EINVAL &&
145 				    (lseek(ii->fd, 0, SEEK_CUR) + bufsize) < 0) {
146 					(void) lseek(ii->fd, 0, 0);
147 					goto again;
148 				}
149 				mopLogErr("read");
150 			}
151 			/* Loop through the packet(s) */
152 #define bhp ((struct bpf_hdr *)bp)
153 			bp = buf;
154 			ep = bp + cc;
155 			while (bp < ep) {
156 				int caplen, hdrlen;
157 
158 				caplen = bhp->bh_caplen;
159 				hdrlen = bhp->bh_hdrlen;
160 				mopProcess(ii, bp + hdrlen);
161 				bp += BPF_WORDALIGN(hdrlen + caplen);
162 			}
163 		}
164 	}
165 }
166