/*
   * Copyright (c) 1993, 1994, 1995, 1996, 1997
   *	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.
   *
   * savefile.c - supports offline use of tcpdump
   *	Extraction/creation by Jeffrey Mogul, DECWRL
   *	Modified by Steve McCanne, LBL.
   *
   * Used to save the received packet headers, after filtering, to
   * a file, and then read them later.
   * The first record in the file contains saved values for the machine
   * dependent values so we can print the dump file on any architecture.
   */
  
  #ifdef HAVE_CONFIG_H
  #include <config.h>
  #endif
  
  #include <pcap-types.h>
  #ifdef _WIN32
  #include <io.h>
  #include <fcntl.h>
  #endif /* _WIN32 */
  
  #include <errno.h>
  #include <memory.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include "pcap-int.h"
  
  #ifdef HAVE_OS_PROTO_H
  #include "os-proto.h"
  #endif
  
  #include "sf-pcap.h"
  #include "sf-pcapng.h"
  
  #ifdef _WIN32
  /*
   * These aren't exported on Windows, because they would only work if both
   * WinPcap and the code using it were to use the Universal CRT; otherwise,
   * a FILE structure in WinPcap and a FILE structure in the code using it
   * could be different if they're using different versions of the C runtime.
   *
   * Instead, pcap/pcap.h defines them as macros that wrap the hopen versions,
   * with the wrappers calling _fileno() and _get_osfhandle() themselves,
   * so that they convert the appropriate CRT version's FILE structure to
   * a HANDLE (which is OS-defined, not CRT-defined, and is part of the Win32
   * and Win64 ABIs).
   */
  static pcap_t *pcap_fopen_offline_with_tstamp_precision(FILE *, u_int, char *);
  static pcap_t *pcap_fopen_offline(FILE *, char *);
  #endif
  
  /*
   * Setting O_BINARY on DOS/Windows is a bit tricky
   */
  #if defined(_WIN32)
    #define SET_BINMODE(f)  _setmode(_fileno(f), _O_BINARY)
  #elif defined(MSDOS)
    #if defined(__HIGHC__)
    #define SET_BINMODE(f)  setmode(f, O_BINARY)
    #else
    #define SET_BINMODE(f)  setmode(fileno(f), O_BINARY)
    #endif
  #endif
  
  static int
  sf_getnonblock(pcap_t *p _U_)
  {
  	/*
  	 * This is a savefile, not a live capture file, so never say
  	 * it's in non-blocking mode.
  	 */
  	return (0);
  }
  
  static int
  sf_setnonblock(pcap_t *p, int nonblock _U_)
  {
  	/*
  	 * This is a savefile, not a live capture file, so reject
  	 * requests to put it in non-blocking mode.  (If it's a
  	 * pipe, it could be put in non-blocking mode, but that
  	 * would significantly complicate the code to read packets,
  	 * as it would have to handle reading partial packets and
  	 * keeping the state of the read.)
  	 */
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "Savefiles cannot be put into non-blocking mode");
  	return (-1);
  }
  
  static int
  sf_stats(pcap_t *p, struct pcap_stat *ps _U_)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "Statistics aren't available from savefiles");
  	return (-1);
  }
  
  #ifdef _WIN32
  static struct pcap_stat *
  sf_stats_ex(pcap_t *p, int *size)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "Statistics aren't available from savefiles");
  	return (NULL);
  }
  
  static int
  sf_setbuff(pcap_t *p, int dim)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "The kernel buffer size cannot be set while reading from a file");
  	return (-1);
  }
  
  static int
  sf_setmode(pcap_t *p, int mode)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "impossible to set mode while reading from a file");
  	return (-1);
  }
  
  static int
  sf_setmintocopy(pcap_t *p, int size)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "The mintocopy parameter cannot be set while reading from a file");
  	return (-1);
  }
  
  static HANDLE
  sf_getevent(pcap_t *pcap)
  {
  	(void)pcap_snprintf(pcap->errbuf, sizeof(pcap->errbuf),
  	    "The read event cannot be retrieved while reading from a file");
  	return (INVALID_HANDLE_VALUE);
  }
  
  static int
  sf_oid_get_request(pcap_t *p, bpf_u_int32 oid _U_, void *data _U_,
      size_t *lenp _U_)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "An OID get request cannot be performed on a file");
  	return (PCAP_ERROR);
  }
  
  static int
  sf_oid_set_request(pcap_t *p, bpf_u_int32 oid _U_, const void *data _U_,
      size_t *lenp _U_)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "An OID set request cannot be performed on a file");
  	return (PCAP_ERROR);
  }
  
  static u_int
  sf_sendqueue_transmit(pcap_t *p, pcap_send_queue *queue, int sync)
  {
  	strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
  	    PCAP_ERRBUF_SIZE);
  	return (0);
  }
  
  static int
  sf_setuserbuffer(pcap_t *p, int size)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "The user buffer cannot be set when reading from a file");
  	return (-1);
  }
  
  static int
  sf_live_dump(pcap_t *p, char *filename, int maxsize, int maxpacks)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "Live packet dumping cannot be performed when reading from a file");
  	return (-1);
  }
  
  static int
  sf_live_dump_ended(pcap_t *p, int sync)
  {
  	pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "Live packet dumping cannot be performed on a pcap_open_dead pcap_t");
  	return (-1);
  }
  
  static PAirpcapHandle
  sf_get_airpcap_handle(pcap_t *pcap)
  {
  	return (NULL);
  }
  #endif
  
  static int
  sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
  {
  	strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
  	    PCAP_ERRBUF_SIZE);
  	return (-1);
  }
  
  /*
   * Set direction flag: Which packets do we accept on a forwarding
   * single device? IN, OUT or both?
   */
  static int
  sf_setdirection(pcap_t *p, pcap_direction_t d _U_)
  {
  	pcap_snprintf(p->errbuf, sizeof(p->errbuf),
  	    "Setting direction is not supported on savefiles");
  	return (-1);
  }
  
  void
  sf_cleanup(pcap_t *p)
  {
  	if (p->rfile != stdin)
  		(void)fclose(p->rfile);
  	if (p->buffer != NULL)
  		free(p->buffer);
  	pcap_freecode(&p->fcode);
  }
  
  pcap_t *
  pcap_open_offline_with_tstamp_precision(const char *fname, u_int precision,
  					char *errbuf)
  {
  	FILE *fp;
  	pcap_t *p;
  
  	if (fname == NULL) {
  		pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
  		    "A null pointer was supplied as the file name");
  		return (NULL);
  	}
  	if (fname[0] == '-' && fname[1] == '\0')
  	{
  		fp = stdin;
  #if defined(_WIN32) || defined(MSDOS)
  		/*
  		 * We're reading from the standard input, so put it in binary
  		 * mode, as savefiles are binary files.
  		 */
  		SET_BINMODE(fp);
  #endif
  	}
  	else {
  		/*
  		 * "b" is supported as of C90, so *all* UN*Xes should
  		 * support it, even though it does nothing.  It's
  		 * required on Windows, as the file is a binary file
  		 * and must be read in binary mode.
  		 */
  		fp = fopen(fname, "rb");
  		if (fp == NULL) {
  			pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
  			    errno, "%s", fname);
  			return (NULL);
  		}
  	}
  	p = pcap_fopen_offline_with_tstamp_precision(fp, precision, errbuf);
  	if (p == NULL) {
  		if (fp != stdin)
  			fclose(fp);
  	}
  	return (p);
  }
  
  pcap_t *
  pcap_open_offline(const char *fname, char *errbuf)
  {
  	return (pcap_open_offline_with_tstamp_precision(fname,
  	    PCAP_TSTAMP_PRECISION_MICRO, errbuf));
  }
  
  #ifdef _WIN32
  pcap_t* pcap_hopen_offline_with_tstamp_precision(intptr_t osfd, u_int precision,
      char *errbuf)
  {
  	int fd;
  	FILE *file;
  
  	fd = _open_osfhandle(osfd, _O_RDONLY);
  	if ( fd < 0 )
  	{
  		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
  		    errno, "_open_osfhandle");
  		return NULL;
  	}
  
  	file = _fdopen(fd, "rb");
  	if ( file == NULL )
  	{
  		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
  		    errno, "_fdopen");
  		return NULL;
  	}
  
  	return pcap_fopen_offline_with_tstamp_precision(file, precision,
  	    errbuf);
  }
  
  pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
  {
  	return pcap_hopen_offline_with_tstamp_precision(osfd,
  	    PCAP_TSTAMP_PRECISION_MICRO, errbuf);
  }
  #endif
  
  static pcap_t *(*check_headers[])(bpf_u_int32, FILE *, u_int, char *, int *) = {
  	pcap_check_header,
  	pcap_ng_check_header
  };
  
  #define	N_FILE_TYPES	(sizeof check_headers / sizeof check_headers[0])
  
  #ifdef _WIN32
  static
  #endif
  pcap_t *
  pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,
      char *errbuf)
  {
  	register pcap_t *p;
  	bpf_u_int32 magic;
  	size_t amt_read;
  	u_int i;
  	int err;
  
  	/*
  	 * Read the first 4 bytes of the file; the network analyzer dump
  	 * file formats we support (pcap and pcapng), and several other
  	 * formats we might support in the future (such as snoop, DOS and
  	 * Windows Sniffer, and Microsoft Network Monitor) all have magic
  	 * numbers that are unique in their first 4 bytes.
  	 */
  	amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
  	if (amt_read != sizeof(magic)) {
  		if (ferror(fp)) {
  			pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
  			    errno, "error reading dump file");
  		} else {
  			pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
  			    "truncated dump file; tried to read %lu file header bytes, only got %lu",
  			    (unsigned long)sizeof(magic),
  			    (unsigned long)amt_read);
  		}
  		return (NULL);
  	}
  
  	/*
  	 * Try all file types.
  	 */
  	for (i = 0; i < N_FILE_TYPES; i++) {
  		p = (*check_headers[i])(magic, fp, precision, errbuf, &err);
  		if (p != NULL) {
  			/* Yup, that's it. */
  			goto found;
  		}
  		if (err) {
  			/*
  			 * Error trying to read the header.
  			 */
  			return (NULL);
  		}
  	}
  
  	/*
  	 * Well, who knows what this mess is....
  	 */
  	pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
  	return (NULL);
  
  found:
  	p->rfile = fp;
  
  	/* Padding only needed for live capture fcode */
  	p->fddipad = 0;
  
  #if !defined(_WIN32) && !defined(MSDOS)
  	/*
  	 * You can do "select()" and "poll()" on plain files on most
  	 * platforms, and should be able to do so on pipes.
  	 *
  	 * You can't do "select()" on anything other than sockets in
  	 * Windows, so, on Win32 systems, we don't have "selectable_fd".
  	 */
  	p->selectable_fd = fileno(fp);
  #endif
  
  	p->read_op = pcap_offline_read;
  	p->inject_op = sf_inject;
  	p->setfilter_op = install_bpf_program;
  	p->setdirection_op = sf_setdirection;
  	p->set_datalink_op = NULL;	/* we don't support munging link-layer headers */
  	p->getnonblock_op = sf_getnonblock;
  	p->setnonblock_op = sf_setnonblock;
  	p->stats_op = sf_stats;
  #ifdef _WIN32
  	p->stats_ex_op = sf_stats_ex;
  	p->setbuff_op = sf_setbuff;
  	p->setmode_op = sf_setmode;
  	p->setmintocopy_op = sf_setmintocopy;
  	p->getevent_op = sf_getevent;
  	p->oid_get_request_op = sf_oid_get_request;
  	p->oid_set_request_op = sf_oid_set_request;
  	p->sendqueue_transmit_op = sf_sendqueue_transmit;
  	p->setuserbuffer_op = sf_setuserbuffer;
  	p->live_dump_op = sf_live_dump;
  	p->live_dump_ended_op = sf_live_dump_ended;
  	p->get_airpcap_handle_op = sf_get_airpcap_handle;
  #endif
  
  	/*
  	 * For offline captures, the standard one-shot callback can
  	 * be used for pcap_next()/pcap_next_ex().
  	 */
  	p->oneshot_callback = pcap_oneshot;
  
  	/*
  	 * Savefiles never require special BPF code generation.
  	 */
  	p->bpf_codegen_flags = 0;
  
  	p->activated = 1;
  
  	return (p);
  }
  
  #ifdef _WIN32
  static
  #endif
  pcap_t *
  pcap_fopen_offline(FILE *fp, char *errbuf)
  {
  	return (pcap_fopen_offline_with_tstamp_precision(fp,
  	    PCAP_TSTAMP_PRECISION_MICRO, errbuf));
  }
  
  /*
   * Read packets from a capture file, and call the callback for each
   * packet.
   * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
   */
  int
  pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  {
  	struct bpf_insn *fcode;
  	int status = 0;
  	int n = 0;
  	u_char *data;
  
  	while (status == 0) {
  		struct pcap_pkthdr h;
  
  		/*
  		 * Has "pcap_breakloop()" been called?
  		 * If so, return immediately - if we haven't read any
  		 * packets, clear the flag and return -2 to indicate
  		 * that we were told to break out of the loop, otherwise
  		 * leave the flag set, so that the *next* call will break
  		 * out of the loop without having read any packets, and
  		 * return the number of packets we've processed so far.
  		 */
  		if (p->break_loop) {
  			if (n == 0) {
  				p->break_loop = 0;
  				return (-2);
  			} else
  				return (n);
  		}
  
  		status = p->next_packet_op(p, &h, &data);
  		if (status) {
  			if (status == 1)
  				return (0);
  			return (status);
  		}
  
  		if ((fcode = p->fcode.bf_insns) == NULL ||
  		    bpf_filter(fcode, data, h.len, h.caplen)) {
  			(*callback)(user, &h, data);
  			if (++n >= cnt && cnt > 0)
  				break;
  		}
  	}
  	/*XXX this breaks semantics tcpslice expects */
  	return (n);
  }