/*
   * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that: (1) source code distributions
   * retain the above copyright notice and this paragraph in its entirety, (2)
   * distributions including binary code include the above copyright notice and
   * this paragraph in its entirety in the documentation or other materials
   * provided with the distribution, and (3) all advertising materials mentioning
   * features or use of this software display the following acknowledgement:
   * ``This product includes software developed by the University of California,
   * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
   * the University nor the names of its contributors may be used to endorse
   * or promote products derived from this software without specific prior
   * written permission.
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
   */
  
  #include "varattrs.h"
  
  #ifndef lint
  static const char copyright[] _U_ =
      "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  The Regents of the University of California.  All rights reserved.\n";
  #endif
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stdarg.h>
  #include <limits.h>
  #ifdef _WIN32
    #include <winsock2.h>
    #include <windows.h>
  
    #define THREAD_HANDLE			HANDLE
    #define THREAD_FUNC_ARG_TYPE		LPVOID
    #define THREAD_FUNC_RETURN_TYPE	DWORD __stdcall
  
    #include "getopt.h"
  #else
    #include <pthread.h>
    #include <signal.h>
    #include <unistd.h>
  
    #define THREAD_HANDLE			pthread_t
    #define THREAD_FUNC_ARG_TYPE		void *
    #define THREAD_FUNC_RETURN_TYPE	void *
  #endif
  #include <errno.h>
  #include <sys/types.h>
  
  #include <pcap.h>
  
  #include "pcap/funcattrs.h"
  
  #ifdef _WIN32
    #include "portability.h"
  #endif
  
  static char *program_name;
  
  /* Forwards */
  static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
  static void PCAP_NORETURN usage(void);
  static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
  static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
  static char *copy_argv(char **);
  
  static pcap_t *pd;
  
  #ifdef _WIN32
  /*
   * Generate a string for a Win32-specific error (i.e. an error generated when
   * calling a Win32 API).
   * For errors occurred during standard C calls, we still use pcap_strerror()
   */
  #define ERRBUF_SIZE	1024
  static const char *
  win32_strerror(DWORD error)
  {
    static char errbuf[ERRBUF_SIZE+1];
    size_t errlen;
  
    FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf,
                  ERRBUF_SIZE, NULL);
  
    /*
     * "FormatMessage()" "helpfully" sticks CR/LF at the end of the
     * message.  Get rid of it.
     */
    errlen = strlen(errbuf);
    if (errlen >= 2) {
      errbuf[errlen - 1] = '\0';
      errbuf[errlen - 2] = '\0';
      errlen -= 2;
    }
    return errbuf;
  }
  #else
  static void
  catch_sigusr1(int sig _U_)
  {
  	printf("Got SIGUSR1\n");
  }
  #endif
  
  static void
  sleep_secs(int secs)
  {
  #ifdef _WIN32
  	Sleep(secs*1000);
  #else
  	unsigned secs_remaining;
  
  	if (secs <= 0)
  		return;
  	secs_remaining = secs;
  	while (secs_remaining != 0)
  		secs_remaining = sleep(secs_remaining);
  #endif
  }
  
  static THREAD_FUNC_RETURN_TYPE
  capture_thread_func(THREAD_FUNC_ARG_TYPE arg)
  {
  	char *device = arg;
  	int packet_count;
  	int status;
  #ifndef _WIN32
  	struct sigaction action;
  	sigset_t mask;
  #endif
  
  #ifndef _WIN32
  	sigemptyset(&mask);
  	action.sa_handler = catch_sigusr1;
  	action.sa_mask = mask;
  	action.sa_flags = 0;
  	if (sigaction(SIGUSR1, &action, NULL) == -1)
  		error("Can't catch SIGUSR1: %s", strerror(errno));
  #endif
  
  	printf("Listening on %s\n", device);
  	for (;;) {
  		packet_count = 0;
  		status = pcap_dispatch(pd, -1, countme,
  		    (u_char *)&packet_count);
  		if (status < 0)
  			break;
  		if (status != 0) {
  			printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
  			    status, packet_count);
  		} else
  			printf("No packets seen by pcap_dispatch\n");
  	}
  	if (status == -2) {
  		/*
  		 * We got interrupted, so perhaps we didn't
  		 * manage to finish a line we were printing.
  		 * Print an extra newline, just in case.
  		 */
  		putchar('\n');
  		printf("Loop got broken\n");
  	}
  	(void)fflush(stdout);
  	if (status == -1) {
  		/*
  		 * Error.  Report it.
  		 */
  		(void)fprintf(stderr, "%s: pcap_loop: %s\n",
  		    program_name, pcap_geterr(pd));
  	}
  	return 0;
  }
  
  int
  main(int argc, char **argv)
  {
  	register int op;
  	register char *cp, *cmdbuf, *device;
  	int immediate = 0;
  	pcap_if_t *devlist;
  	bpf_u_int32 localnet, netmask;
  	struct bpf_program fcode;
  	char ebuf[PCAP_ERRBUF_SIZE];
  	int status;
  	THREAD_HANDLE capture_thread;
  #ifndef _WIN32
  	void *retval;
  #endif
  
  	device = NULL;
  	if ((cp = strrchr(argv[0], '/')) != NULL)
  		program_name = cp + 1;
  	else
  		program_name = argv[0];
  
  	opterr = 0;
  	while ((op = getopt(argc, argv, "i:")) != -1) {
  		switch (op) {
  
  		case 'i':
  			device = optarg;
  			break;
  
  		default:
  			usage();
  			/* NOTREACHED */
  		}
  	}
  
  	if (device == NULL) {
  		if (pcap_findalldevs(&devlist, ebuf) == -1)
  			error("%s", ebuf);
  		if (devlist == NULL)
  			error("no interfaces available for capture");
  		device = strdup(devlist->name);
  		pcap_freealldevs(devlist);
  	}
  	*ebuf = '\0';
  	pd = pcap_create(device, ebuf);
  	if (pd == NULL)
  		error("%s", ebuf);
  	status = pcap_set_snaplen(pd, 65535);
  	if (status != 0)
  		error("%s: pcap_set_snaplen failed: %s",
  			    device, pcap_statustostr(status));
  	if (immediate) {
  		status = pcap_set_immediate_mode(pd, 1);
  		if (status != 0)
  			error("%s: pcap_set_immediate_mode failed: %s",
  			    device, pcap_statustostr(status));
  	}
  	status = pcap_set_timeout(pd, 5*60*1000);
  	if (status != 0)
  		error("%s: pcap_set_timeout failed: %s",
  		    device, pcap_statustostr(status));
  	status = pcap_activate(pd);
  	if (status < 0) {
  		/*
  		 * pcap_activate() failed.
  		 */
  		error("%s: %s\n(%s)", device,
  		    pcap_statustostr(status), pcap_geterr(pd));
  	} else if (status > 0) {
  		/*
  		 * pcap_activate() succeeded, but it's warning us
  		 * of a problem it had.
  		 */
  		warning("%s: %s\n(%s)", device,
  		    pcap_statustostr(status), pcap_geterr(pd));
  	}
  	if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
  		localnet = 0;
  		netmask = 0;
  		warning("%s", ebuf);
  	}
  	cmdbuf = copy_argv(&argv[optind]);
  
  	if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
  		error("%s", pcap_geterr(pd));
  
  	if (pcap_setfilter(pd, &fcode) < 0)
  		error("%s", pcap_geterr(pd));
  
  #ifdef _WIN32
  	capture_thread = CreateThread(NULL, 0, capture_thread_func, device,
  	    0, NULL);
  	if (capture_thread == NULL)
  		error("Can't create capture thread: %s",
  		    win32_strerror(GetLastError()));
  #else
  	status = pthread_create(&capture_thread, NULL, capture_thread_func,
  	    device);
  	if (status != 0)
  		error("Can't create capture thread: %s", strerror(status));
  #endif
  	sleep_secs(60);
  	pcap_breakloop(pd);
  #ifdef _WIN32
  	printf("Setting event\n");
  	if (!SetEvent(pcap_getevent(pd)))
  		error("Can't set event for pcap_t: %s",
  		    win32_strerror(GetLastError()));
  	if (WaitForSingleObject(capture_thread, INFINITE) == WAIT_FAILED)
  		error("Wait for thread termination failed: %s",
  		    win32_strerror(GetLastError()));
  	CloseHandle(capture_thread);
  #else
  	printf("Sending SIGUSR1\n");
  	status = pthread_kill(capture_thread, SIGUSR1);
  	if (status != 0)
  		warning("Can't interrupt capture thread: %s", strerror(status));
  	status = pthread_join(capture_thread, &retval);
  	if (status != 0)
  		error("Wait for thread termination failed: %s",
  		    strerror(status));
  #endif
  
  	pcap_close(pd);
  	pcap_freecode(&fcode);
  	exit(status == -1 ? 1 : 0);
  }
  
  static void
  countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
  {
  	int *counterp = (int *)user;
  
  	(*counterp)++;
  }
  
  static void
  usage(void)
  {
  	(void)fprintf(stderr, "Usage: %s [ -m ] [ -i interface ] [ -t timeout] [expression]\n",
  	    program_name);
  	exit(1);
  }
  
  /* VARARGS */
  static void
  error(const char *fmt, ...)
  {
  	va_list ap;
  
  	(void)fprintf(stderr, "%s: ", program_name);
  	va_start(ap, fmt);
  	(void)vfprintf(stderr, fmt, ap);
  	va_end(ap);
  	if (*fmt) {
  		fmt += strlen(fmt);
  		if (fmt[-1] != '\n')
  			(void)fputc('\n', stderr);
  	}
  	exit(1);
  	/* NOTREACHED */
  }
  
  /* VARARGS */
  static void
  warning(const char *fmt, ...)
  {
  	va_list ap;
  
  	(void)fprintf(stderr, "%s: WARNING: ", program_name);
  	va_start(ap, fmt);
  	(void)vfprintf(stderr, fmt, ap);
  	va_end(ap);
  	if (*fmt) {
  		fmt += strlen(fmt);
  		if (fmt[-1] != '\n')
  			(void)fputc('\n', stderr);
  	}
  }
  
  /*
   * Copy arg vector into a new buffer, concatenating arguments with spaces.
   */
  static char *
  copy_argv(register char **argv)
  {
  	register char **p;
  	register u_int len = 0;
  	char *buf;
  	char *src, *dst;
  
  	p = argv;
  	if (*p == 0)
  		return 0;
  
  	while (*p)
  		len += strlen(*p++) + 1;
  
  	buf = (char *)malloc(len);
  	if (buf == NULL)
  		error("copy_argv: malloc");
  
  	p = argv;
  	dst = buf;
  	while ((src = *p++) != NULL) {
  		while ((*dst++ = *src++) != '\0')
  			;
  		dst[-1] = ' ';
  	}
  	dst[-1] = '\0';
  
  	return buf;
  }