1 /* $OpenBSD: loop-bsd.c,v 1.12 2006/10/11 20:56:59 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 #ifndef lint 28 static const char rcsid[] = 29 "$OpenBSD: loop-bsd.c,v 1.12 2006/10/11 20:56:59 deraadt Exp $"; 30 #endif 31 32 #include <errno.h> 33 #include <stdlib.h> 34 #include <string.h> 35 #include <unistd.h> 36 #if defined(__bsdi__) || defined(__FreeBSD__) 37 #include <sys/time.h> 38 #endif 39 #include <net/bpf.h> 40 #include <sys/ioctl.h> 41 42 #include "os.h" 43 #include "common/common.h" 44 #include "common/mopdef.h" 45 46 int 47 mopOpenRC(struct if_info *p, int trans) 48 { 49 #ifndef NORC 50 return (*(p->iopen))(p->if_name, O_RDWR, MOP_K_PROTO_RC, trans); 51 #else 52 return (-1); 53 #endif 54 } 55 56 int 57 mopOpenDL(struct if_info *p, int trans) 58 { 59 #ifndef NODL 60 return (*(p->iopen))(p->if_name, O_RDWR, MOP_K_PROTO_DL, trans); 61 #else 62 return (-1); 63 #endif 64 } 65 66 void 67 mopReadRC(void) 68 { 69 } 70 71 void 72 mopReadDL(void) 73 { 74 } 75 76 /* 77 * The list of all interfaces that are being listened to. loop() 78 * "selects" on the descriptors in this list. 79 */ 80 struct if_info *iflist; 81 82 void mopProcess(struct if_info *, u_char *); 83 84 /* 85 * Loop indefinitely listening for MOP requests on the 86 * interfaces in 'iflist'. 87 */ 88 void 89 Loop(void) 90 { 91 u_char *buf, *bp, *ep; 92 int cc; 93 fd_set fds, listeners; 94 int bufsize, maxfd = 0; 95 struct if_info *ii; 96 97 if (iflist == 0) { 98 syslog(LOG_ERR, "no interfaces"); 99 exit(0); 100 } 101 if (iflist->fd != -1) 102 if (ioctl(iflist->fd, BIOCGBLEN, (caddr_t)&bufsize) < 0) { 103 syslog(LOG_ERR, "BIOCGBLEN: %m"); 104 exit(0); 105 } 106 107 buf = malloc(bufsize); 108 if (buf == 0) { 109 syslog(LOG_ERR, "malloc: %m"); 110 exit(0); 111 } 112 /* 113 * Find the highest numbered file descriptor for select(). 114 * Initialize the set of descriptors to listen to. 115 */ 116 FD_ZERO(&fds); 117 for (ii = iflist; ii; ii = ii->next) 118 if (ii->fd != -1) { 119 FD_SET(ii->fd, &fds); 120 if (ii->fd > maxfd) 121 maxfd = ii->fd; 122 } 123 124 while (1) { 125 listeners = fds; 126 if (select(maxfd + 1, &listeners, NULL, NULL, NULL) < 0) { 127 syslog(LOG_ERR, "select: %m"); 128 exit(0); 129 } 130 for (ii = iflist; ii; ii = ii->next) 131 if (ii->fd != -1) { 132 if (!FD_ISSET(ii->fd, &listeners)) 133 continue; 134 again: 135 cc = read(ii->fd, buf, bufsize); 136 /* Don't choke when we get ptraced */ 137 if (cc < 0 && errno == EINTR) 138 goto again; 139 /* Due to a SunOS bug, after 2^31 bytes, the file 140 * offset overflows and read fails with EINVAL. The 141 * lseek() to 0 will fix things. */ 142 if (cc < 0) { 143 if (errno == EINVAL && (lseek(ii->fd, 0, 144 SEEK_CUR) + bufsize) < 0) { 145 lseek(ii->fd, 0, SEEK_SET); 146 goto again; 147 } 148 syslog(LOG_ERR, "read: %m"); 149 exit(0); 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