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      1 /*	$NetBSD: npfd.c,v 1.9 2017/10/16 11:18:43 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2015 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Mindaugas Rasiukevicius.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __RCSID("$NetBSD: npfd.c,v 1.9 2017/10/16 11:18:43 christos Exp $");
     34 
     35 #include <stdio.h>
     36 #include <string.h>
     37 #include <fcntl.h>
     38 #include <signal.h>
     39 #include <stdlib.h>
     40 #include <unistd.h>
     41 #include <stdbool.h>
     42 #include <poll.h>
     43 #include <errno.h>
     44 #include <err.h>
     45 #include <syslog.h>
     46 #include <util.h>
     47 
     48 #include <net/npf.h>
     49 
     50 #include "npfd.h"
     51 
     52 static volatile sig_atomic_t hup, stats, done, flush;
     53 
     54 static int
     55 npfd_getctl(void)
     56 {
     57 	int fd, ver;
     58 
     59 	fd = open(NPF_DEV_PATH, O_RDONLY);
     60 	if (fd == -1) {
     61 		err(EXIT_FAILURE, "cannot open '%s'", NPF_DEV_PATH);
     62 	}
     63 	if (ioctl(fd, IOC_NPF_VERSION, &ver) == -1) {
     64 		err(EXIT_FAILURE, "ioctl(IOC_NPF_VERSION)");
     65 	}
     66 	if (ver != NPF_VERSION) {
     67 		errx(EXIT_FAILURE,
     68 		    "Incompatible NPF interface version (%d, kernel %d)\n"
     69 		    "Hint: update userland?", NPF_VERSION, ver);
     70 	}
     71 	return fd;
     72 }
     73 
     74 static void
     75 npfd_event_loop(npfd_log_t *log, int delay)
     76 {
     77 	struct pollfd pfd;
     78 	size_t count = 0;
     79 
     80 	pfd.fd = npfd_log_getsock(log);
     81 	pfd.events = POLLHUP | POLLIN;
     82 
     83 	while  (!done) {
     84 		if (hup) {
     85 			hup = false;
     86 			npfd_log_file_reopen(log, false);
     87 		}
     88 		if (stats) {
     89 			stats = false;
     90 			npfd_log_stats(log);
     91 		}
     92 		if (flush) {
     93 			flush = false;
     94 			npfd_log_flush(log);
     95 			count = 0;
     96 		}
     97 		switch (poll(&pfd, 1, delay)) {
     98 		case -1:
     99 			if (errno == EINTR)
    100 				continue;
    101 			syslog(LOG_ERR, "poll failed: %m");
    102 			exit(EXIT_FAILURE);
    103 			/*NOTREACHED*/
    104 		case 0:
    105 			npfd_log_flush(log);
    106 			count = 0;
    107 			continue;
    108 		default:
    109 			if (count++ >= 100) {
    110 				npfd_log_flush(log);
    111 				count = 0;
    112 			}
    113 			if (npfd_log(log) <= 0)
    114 				npfd_log_pcap_reopen(log);
    115 		}
    116 
    117 	}
    118 	npfd_log_destroy(log);
    119 }
    120 
    121 static void
    122 sighandler(int sig)
    123 {
    124 	switch (sig) {
    125 	case SIGHUP:
    126 		hup = true;
    127 		break;
    128 	case SIGTERM:
    129 	case SIGINT:
    130 		done = true;
    131 		break;
    132 	case SIGINFO:
    133 		stats = true;
    134 		break;
    135 	case SIGALRM:
    136 		flush = true;
    137 		break;
    138 	default:
    139 		syslog(LOG_ERR, "Unhandled signal %d", sig);
    140 		break;
    141 	}
    142 }
    143 
    144 static __dead void
    145 usage(void)
    146 {
    147 	fprintf(stderr, "Usage: %s [-D] [-d <delay>] [-i <interface>]"
    148 	    " [-f <filename>] [-p <pidfile>] [-s <snaplen>] expression\n",
    149 	    getprogname());
    150 	exit(EXIT_FAILURE);
    151 }
    152 
    153 static char *
    154 copyargs(int argc, char **argv)
    155 {
    156 	if (argc == 0)
    157 		return NULL;
    158 
    159 	size_t len = 0, p = 0;
    160 	char *buf = NULL;
    161 
    162 	for (int i = 0; i < argc; i++) {
    163 		size_t l = strlen(argv[i]);
    164 		if (p + l + 1 >= len)
    165 			buf = erealloc(buf, len = p + l + 1);
    166 		memcpy(buf + p, argv[i], l);
    167 		p += l;
    168 		buf[p++] = i == argc - 1 ? '\0' : ' ';
    169 	}
    170 	return buf;
    171 }
    172 
    173 int
    174 main(int argc, char **argv)
    175 {
    176 	bool daemon_off = false;
    177 	int ch;
    178 
    179 	int delay = 5 * 1000;
    180 	const char *iface = "npflog0";
    181 	int snaplen = 116;
    182 	char *pidname = NULL;
    183 	char *filename = NULL;
    184 
    185 	int fd = npfd_getctl();
    186 	(void)close(fd);
    187 
    188 	while ((ch = getopt(argc, argv, "Dd:f:i:p:s:")) != -1) {
    189 		switch (ch) {
    190 		case 'D':
    191 			daemon_off = true;
    192 			break;
    193 		case 'd':
    194 			delay = atoi(optarg) * 1000;
    195 			break;
    196 		case 'f':
    197 			filename = optarg;
    198 			break;
    199 		case 'i':
    200 			iface = optarg;
    201 			break;
    202 		case 'p':
    203 			pidname = optarg;
    204 			break;
    205 		case 's':
    206 			snaplen = atoi(optarg);
    207 			break;
    208 		default:
    209 			usage();
    210 		}
    211 	}
    212 
    213 	argc -= optind;
    214 	argv += optind;
    215 
    216 	char *filter = copyargs(argc, argv);
    217 
    218 	npfd_log_t *log = npfd_log_create(filename, iface, filter, snaplen);
    219 
    220 	if (!daemon_off) {
    221 		if (daemon(0, 0) == -1)
    222 			err(EXIT_FAILURE, "daemon");
    223 		pidfile(pidname);
    224 	}
    225 
    226 	openlog(argv[0], LOG_PID | LOG_NDELAY | LOG_CONS, LOG_DAEMON);
    227 	signal(SIGHUP, sighandler);
    228 	signal(SIGINT, sighandler);
    229 	signal(SIGTERM, sighandler);
    230 	signal(SIGINFO, sighandler);
    231 	signal(SIGQUIT, sighandler);
    232 
    233 	npfd_event_loop(log, delay);
    234 
    235 	closelog();
    236 
    237 	return 0;
    238 }
    239