| 1 |  |  | /*	$OpenBSD: loop-bsd.c,v 1.13 2009/10/27 23:59:52 deraadt 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 <errno.h> | 
    
    | 28 |  |  | #include <stdlib.h> | 
    
    | 29 |  |  | #include <string.h> | 
    
    | 30 |  |  | #include <unistd.h> | 
    
    | 31 |  |  | #if defined(__bsdi__) || defined(__FreeBSD__) | 
    
    | 32 |  |  | #include <sys/time.h> | 
    
    | 33 |  |  | #endif | 
    
    | 34 |  |  | #include <net/bpf.h> | 
    
    | 35 |  |  | #include <sys/ioctl.h> | 
    
    | 36 |  |  |  | 
    
    | 37 |  |  | #include "os.h" | 
    
    | 38 |  |  | #include "common/common.h" | 
    
    | 39 |  |  | #include "common/mopdef.h" | 
    
    | 40 |  |  |  | 
    
    | 41 |  |  | int | 
    
    | 42 |  |  | mopOpenRC(struct if_info *p, int trans) | 
    
    | 43 |  |  | { | 
    
    | 44 |  |  | #ifndef NORC | 
    
    | 45 |  |  | 	return (*(p->iopen))(p->if_name, O_RDWR, MOP_K_PROTO_RC, trans); | 
    
    | 46 |  |  | #else | 
    
    | 47 |  |  | 	return (-1); | 
    
    | 48 |  |  | #endif | 
    
    | 49 |  |  | } | 
    
    | 50 |  |  |  | 
    
    | 51 |  |  | int | 
    
    | 52 |  |  | mopOpenDL(struct if_info *p, int trans) | 
    
    | 53 |  |  | { | 
    
    | 54 |  |  | #ifndef NODL | 
    
    | 55 |  |  | 	return (*(p->iopen))(p->if_name, O_RDWR, MOP_K_PROTO_DL, trans); | 
    
    | 56 |  |  | #else | 
    
    | 57 |  |  | 	return (-1); | 
    
    | 58 |  |  | #endif | 
    
    | 59 |  |  | } | 
    
    | 60 |  |  |  | 
    
    | 61 |  |  | void | 
    
    | 62 |  |  | mopReadRC(void) | 
    
    | 63 |  |  | { | 
    
    | 64 |  |  | } | 
    
    | 65 |  |  |  | 
    
    | 66 |  |  | void | 
    
    | 67 |  |  | mopReadDL(void) | 
    
    | 68 |  |  | { | 
    
    | 69 |  |  | } | 
    
    | 70 |  |  |  | 
    
    | 71 |  |  | /* | 
    
    | 72 |  |  |  * The list of all interfaces that are being listened to.  loop() | 
    
    | 73 |  |  |  * "selects" on the descriptors in this list. | 
    
    | 74 |  |  |  */ | 
    
    | 75 |  |  | struct if_info *iflist; | 
    
    | 76 |  |  |  | 
    
    | 77 |  |  | void   mopProcess(struct if_info *, u_char *); | 
    
    | 78 |  |  |  | 
    
    | 79 |  |  | /* | 
    
    | 80 |  |  |  * Loop indefinitely listening for MOP requests on the | 
    
    | 81 |  |  |  * interfaces in 'iflist'. | 
    
    | 82 |  |  |  */ | 
    
    | 83 |  |  | void | 
    
    | 84 |  |  | Loop(void) | 
    
    | 85 |  |  | { | 
    
    | 86 |  |  | 	u_char		*buf, *bp, *ep; | 
    
    | 87 |  |  | 	int		 cc; | 
    
    | 88 |  |  | 	fd_set		 fds, listeners; | 
    
    | 89 |  |  | 	int		 bufsize, maxfd = 0; | 
    
    | 90 |  |  | 	struct if_info	*ii; | 
    
    | 91 |  |  |  | 
    
    | 92 |  |  | 	if (iflist == 0) { | 
    
    | 93 |  |  | 		syslog(LOG_ERR, "no interfaces"); | 
    
    | 94 |  |  | 		exit(0); | 
    
    | 95 |  |  | 	} | 
    
    | 96 |  |  | 	if (iflist->fd != -1) | 
    
    | 97 |  |  | 		if (ioctl(iflist->fd, BIOCGBLEN, (caddr_t)&bufsize) < 0) { | 
    
    | 98 |  |  | 			syslog(LOG_ERR, "BIOCGBLEN: %m"); | 
    
    | 99 |  |  | 			exit(0); | 
    
    | 100 |  |  | 		} | 
    
    | 101 |  |  |  | 
    
    | 102 |  |  | 	buf = malloc(bufsize); | 
    
    | 103 |  |  | 	if (buf == 0) { | 
    
    | 104 |  |  | 		syslog(LOG_ERR, "malloc: %m"); | 
    
    | 105 |  |  | 		exit(0); | 
    
    | 106 |  |  | 	} | 
    
    | 107 |  |  | 	/* | 
    
    | 108 |  |  |          * Find the highest numbered file descriptor for select(). | 
    
    | 109 |  |  |          * Initialize the set of descriptors to listen to. | 
    
    | 110 |  |  |          */ | 
    
    | 111 |  |  | 	FD_ZERO(&fds); | 
    
    | 112 |  |  | 	for (ii = iflist; ii; ii = ii->next) | 
    
    | 113 |  |  | 		if (ii->fd != -1) { | 
    
    | 114 |  |  | 			FD_SET(ii->fd, &fds); | 
    
    | 115 |  |  | 			if (ii->fd > maxfd) | 
    
    | 116 |  |  | 				maxfd = ii->fd; | 
    
    | 117 |  |  | 		} | 
    
    | 118 |  |  |  | 
    
    | 119 |  |  | 	while (1) { | 
    
    | 120 |  |  | 		listeners = fds; | 
    
    | 121 |  |  | 		if (select(maxfd + 1, &listeners, NULL, NULL, NULL) < 0) { | 
    
    | 122 |  |  | 			syslog(LOG_ERR, "select: %m"); | 
    
    | 123 |  |  | 			exit(0); | 
    
    | 124 |  |  | 		} | 
    
    | 125 |  |  | 		for (ii = iflist; ii; ii = ii->next) | 
    
    | 126 |  |  | 			if (ii->fd != -1) { | 
    
    | 127 |  |  | 				if (!FD_ISSET(ii->fd, &listeners)) | 
    
    | 128 |  |  | 					continue; | 
    
    | 129 |  |  | again: | 
    
    | 130 |  |  | 			cc = read(ii->fd, buf, bufsize); | 
    
    | 131 |  |  | 			/* Don't choke when we get ptraced */ | 
    
    | 132 |  |  | 			if (cc < 0 && errno == EINTR) | 
    
    | 133 |  |  | 				goto again; | 
    
    | 134 |  |  | 			/* Due to a SunOS bug, after 2^31 bytes, the file | 
    
    | 135 |  |  | 			 * offset overflows and read fails with EINVAL.  The | 
    
    | 136 |  |  | 			 * lseek() to 0 will fix things. */ | 
    
    | 137 |  |  | 			if (cc < 0) { | 
    
    | 138 |  |  | 				if (errno == EINVAL && (lseek(ii->fd, 0, | 
    
    | 139 |  |  | 				    SEEK_CUR) + bufsize) < 0) { | 
    
    | 140 |  |  | 					lseek(ii->fd, 0, SEEK_SET); | 
    
    | 141 |  |  | 					goto again; | 
    
    | 142 |  |  | 				} | 
    
    | 143 |  |  | 				syslog(LOG_ERR, "read: %m"); | 
    
    | 144 |  |  | 				exit(0); | 
    
    | 145 |  |  | 			} | 
    
    | 146 |  |  | 			/* Loop through the packet(s) */ | 
    
    | 147 |  |  | #define bhp ((struct bpf_hdr *)bp) | 
    
    | 148 |  |  | 			bp = buf; | 
    
    | 149 |  |  | 			ep = bp + cc; | 
    
    | 150 |  |  | 			while (bp < ep) { | 
    
    | 151 |  |  | 				int caplen, hdrlen; | 
    
    | 152 |  |  |  | 
    
    | 153 |  |  | 				caplen = bhp->bh_caplen; | 
    
    | 154 |  |  | 				hdrlen = bhp->bh_hdrlen; | 
    
    | 155 |  |  | 				mopProcess(ii, bp + hdrlen); | 
    
    | 156 |  |  | 				bp += BPF_WORDALIGN(hdrlen + caplen); | 
    
    | 157 |  |  | 			} | 
    
    | 158 |  |  | 		} | 
    
    | 159 |  |  | 	} | 
    
    | 160 |  |  | } |