nexmon – Rev 1
?pathlinks?
/*
* 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
#ifdef WIN32
#include <pcap-stdinc.h>
#else /* WIN32 */
#if HAVE_INTTYPES_H
#include <inttypes.h>
#elif HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_SYS_BITYPES_H
#include <sys/bitypes.h>
#endif
#include <sys/types.h>
#endif /* WIN32 */
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pcap-int.h"
#include "pcap/usb.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#include "sf-pcap.h"
#include "sf-pcap-ng.h"
/*
* 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, char *errbuf)
{
/*
* 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, char *errbuf)
{
/*
* 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.)
*/
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)
{
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"Statistics aren't available from savefiles");
return (-1);
}
#ifdef WIN32
static int
sf_setbuff(pcap_t *p, int dim)
{
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)
{
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)
{
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"The mintocopy parameter cannot be set while reading from a file");
return (-1);
}
#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)
{
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[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 {
#if !defined(WIN32) && !defined(MSDOS)
fp = fopen(fname, "r");
#else
fp = fopen(fname, "rb");
#endif
if (fp == NULL) {
snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
pcap_strerror(errno));
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 )
{
snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
return NULL;
}
file = _fdopen(fd, "rb");
if ( file == NULL )
{
snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
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 pcap-ng), 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)) {
snprintf(errbuf, PCAP_ERRBUF_SIZE,
"error reading dump file: %s",
pcap_strerror(errno));
} else {
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....
*/
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->setbuff_op = sf_setbuff;
p->setmode_op = sf_setmode;
p->setmintocopy_op = sf_setmintocopy;
#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);
}