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 } 161