/*

 * 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 <limits.h> /* for INT_MAX */

#include "pcap-int.h"

#ifdef HAVE_OS_PROTO_H

#include "os-proto.h"

#endif

#include "sf-pcap.h"

#include "sf-pcapng.h"

#include "pcap-common.h"

#ifdef _WIN32

/*

 * These aren't exported on Windows, because they would only work if both

 * WinPcap/Npcap and the code using it were to use the Universal CRT; otherwise,

 * a FILE structure in WinPcap/Npcap 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)

{

	pcap_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_)

{

	pcap_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");

		_close(fd);

		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

/*

 * Given a link-layer header type and snapshot length, return a

 * snapshot length to use when reading the file; it's guaranteed

 * to be > 0 and <= INT_MAX.

 *

 * XXX - the only reason why we limit it to <= INT_MAX is so that

 * it fits in p->snapshot, and the only reason that p->snapshot is

 * signed is that pcap_snapshot() returns an int, not an unsigned int.

 */

bpf_u_int32

pcap_adjust_snapshot(bpf_u_int32 linktype, bpf_u_int32 snaplen)

{

	if (snaplen == 0 || snaplen > INT_MAX) {

		/*

		 * Bogus snapshot length; use the maximum for this

		 * link-layer type as a fallback.

		 *

		 * XXX - we don't clamp snapshot lengths that are

		 * <= INT_MAX but > max_snaplen_for_dlt(linktype),

		 * so a capture file could cause us to allocate

		 * a Really Big Buffer.

		 */

		snaplen = max_snaplen_for_dlt(linktype);

	}

	return snaplen;

}

static pcap_t *(*check_headers[])(const uint8_t *, 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;

	uint8_t magic[4];

	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(&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 %" PRIsize " file header bytes, only got %" PRIsize,

			    sizeof(magic), 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);

}