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