tcpdump/util.c
2009-05-21 10:32:59 -07:00

609 lines
14 KiB
C

/*
* Copyright (c) 1990, 1991, 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.
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/util.c,v 1.109 2007-01-29 09:59:42 hannes Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <sys/stat.h>
#include <errno.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <pcap.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include "interface.h"
char * ts_format(register int, register int);
/*
* Print out a null-terminated filename (or other ascii string).
* If ep is NULL, assume no truncation check is needed.
* Return true if truncated.
*/
int
fn_print(register const u_char *s, register const u_char *ep)
{
register int ret;
register u_char c;
ret = 1; /* assume truncated */
while (ep == NULL || s < ep) {
c = *s++;
if (c == '\0') {
ret = 0;
break;
}
if (!isascii(c)) {
c = toascii(c);
putchar('M');
putchar('-');
}
if (!isprint(c)) {
c ^= 0x40; /* DEL to ?, others to alpha */
putchar('^');
}
putchar(c);
}
return(ret);
}
/*
* Print out a counted filename (or other ascii string).
* If ep is NULL, assume no truncation check is needed.
* Return true if truncated.
*/
int
fn_printn(register const u_char *s, register u_int n,
register const u_char *ep)
{
register u_char c;
while (n > 0 && (ep == NULL || s < ep)) {
n--;
c = *s++;
if (!isascii(c)) {
c = toascii(c);
putchar('M');
putchar('-');
}
if (!isprint(c)) {
c ^= 0x40; /* DEL to ?, others to alpha */
putchar('^');
}
putchar(c);
}
return (n == 0) ? 0 : 1;
}
/*
* Print out a null-padded filename (or other ascii string).
* If ep is NULL, assume no truncation check is needed.
* Return true if truncated.
*/
int
fn_printzp(register const u_char *s, register u_int n,
register const u_char *ep)
{
register int ret;
register u_char c;
ret = 1; /* assume truncated */
while (n > 0 && (ep == NULL || s < ep)) {
n--;
c = *s++;
if (c == '\0') {
ret = 0;
break;
}
if (!isascii(c)) {
c = toascii(c);
putchar('M');
putchar('-');
}
if (!isprint(c)) {
c ^= 0x40; /* DEL to ?, others to alpha */
putchar('^');
}
putchar(c);
}
return (n == 0) ? 0 : ret;
}
/*
* Format the timestamp
*/
char *
ts_format(register int sec, register int usec)
{
static char buf[sizeof("00:00:00.000000")];
(void)snprintf(buf, sizeof(buf), "%02d:%02d:%02d.%06u",
sec / 3600, (sec % 3600) / 60, sec % 60, usec);
return buf;
}
/*
* Print the timestamp
*/
void
ts_print(register const struct timeval *tvp)
{
register int s;
struct tm *tm;
time_t Time;
static unsigned b_sec;
static unsigned b_usec;
int d_usec;
int d_sec;
switch (tflag) {
case 0: /* Default */
s = (tvp->tv_sec + thiszone) % 86400;
(void)printf("%s ", ts_format(s, tvp->tv_usec));
break;
case 1: /* No time stamp */
break;
case 2: /* Unix timeval style */
(void)printf("%u.%06u ",
(unsigned)tvp->tv_sec,
(unsigned)tvp->tv_usec);
break;
case 3: /* Microseconds since previous packet */
case 5: /* Microseconds since first packet */
if (b_sec == 0) {
/* init timestamp for first packet */
b_usec = tvp->tv_usec;
b_sec = tvp->tv_sec;
}
d_usec = tvp->tv_usec - b_usec;
d_sec = tvp->tv_sec - b_sec;
while (d_usec < 0) {
d_usec += 1000000;
d_sec--;
}
(void)printf("%s ", ts_format(d_sec, d_usec));
if (tflag == 3) { /* set timestamp for last packet */
b_sec = tvp->tv_sec;
b_usec = tvp->tv_usec;
}
break;
case 4: /* Default + Date*/
s = (tvp->tv_sec + thiszone) % 86400;
Time = (tvp->tv_sec + thiszone) - s;
tm = gmtime (&Time);
if (!tm)
printf("Date fail ");
else
printf("%04d-%02d-%02d %s ",
tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
ts_format(s, tvp->tv_usec));
break;
}
}
/*
* Print a relative number of seconds (e.g. hold time, prune timer)
* in the form 5m1s. This does no truncation, so 32230861 seconds
* is represented as 1y1w1d1h1m1s.
*/
void
relts_print(int secs)
{
static const char *lengths[] = {"y", "w", "d", "h", "m", "s"};
static const int seconds[] = {31536000, 604800, 86400, 3600, 60, 1};
const char **l = lengths;
const int *s = seconds;
if (secs == 0) {
(void)printf("0s");
return;
}
if (secs < 0) {
(void)printf("-");
secs = -secs;
}
while (secs > 0) {
if (secs >= *s) {
(void)printf("%d%s", secs / *s, *l);
secs -= (secs / *s) * *s;
}
s++;
l++;
}
}
/*
* this is a generic routine for printing unknown data;
* we pass on the linefeed plus indentation string to
* get a proper output - returns 0 on error
*/
int
print_unknown_data(const u_char *cp,const char *ident,int len)
{
if (len < 0) {
printf("%sDissector error: print_unknown_data called with negative length",
ident);
return(0);
}
if (snapend - cp < len)
len = snapend - cp;
if (len < 0) {
printf("%sDissector error: print_unknown_data called with pointer past end of packet",
ident);
return(0);
}
hex_print(ident,cp,len);
return(1); /* everything is ok */
}
/*
* Convert a token value to a string; use "fmt" if not found.
*/
const char *
tok2strbuf(register const struct tok *lp, register const char *fmt,
register int v, char *buf, size_t bufsize)
{
if (lp != NULL) {
while (lp->s != NULL) {
if (lp->v == v)
return (lp->s);
++lp;
}
}
if (fmt == NULL)
fmt = "#%d";
(void)snprintf(buf, bufsize, fmt, v);
return (const char *)buf;
}
/*
* Convert a token value to a string; use "fmt" if not found.
*/
const char *
tok2str(register const struct tok *lp, register const char *fmt,
register int v)
{
static char buf[4][128];
static int idx = 0;
char *ret;
ret = buf[idx];
idx = (idx+1) & 3;
return tok2strbuf(lp, fmt, v, ret, sizeof(buf[0]));
}
/*
* Convert a bit token value to a string; use "fmt" if not found.
* this is useful for parsing bitfields, the output strings are seperated
* if the s field is positive.
*/
static char *
bittok2str_internal(register const struct tok *lp, register const char *fmt,
register int v, register int sep)
{
static char buf[256]; /* our stringbuffer */
int buflen=0;
register int rotbit; /* this is the bit we rotate through all bitpositions */
register int tokval;
while (lp != NULL && lp->s != NULL) {
tokval=lp->v; /* load our first value */
rotbit=1;
while (rotbit != 0) {
/*
* lets AND the rotating bit with our token value
* and see if we have got a match
*/
if (tokval == (v&rotbit)) {
/* ok we have found something */
buflen+=snprintf(buf+buflen, sizeof(buf)-buflen, "%s%s",
lp->s, sep ? ", " : "");
break;
}
rotbit=rotbit<<1; /* no match - lets shift and try again */
}
lp++;
}
/* user didn't want string seperation - no need to cut off trailing seperators */
if (!sep) {
return (buf);
}
if (buflen != 0) { /* did we find anything */
/* yep, set the the trailing zero 2 bytes before to eliminate the last comma & whitespace */
buf[buflen-2] = '\0';
return (buf);
}
else {
/* bummer - lets print the "unknown" message as advised in the fmt string if we got one */
if (fmt == NULL)
fmt = "#%d";
(void)snprintf(buf, sizeof(buf), fmt, v);
return (buf);
}
}
/*
* Convert a bit token value to a string; use "fmt" if not found.
* this is useful for parsing bitfields, the output strings are not seperated.
*/
char *
bittok2str_nosep(register const struct tok *lp, register const char *fmt,
register int v)
{
return (bittok2str_internal(lp, fmt, v, 0));
}
/*
* Convert a bit token value to a string; use "fmt" if not found.
* this is useful for parsing bitfields, the output strings are comma seperated.
*/
char *
bittok2str(register const struct tok *lp, register const char *fmt,
register int v)
{
return (bittok2str_internal(lp, fmt, v, 1));
}
/*
* Convert a value to a string using an array; the macro
* tok2strary() in <interface.h> is the public interface to
* this function and ensures that the second argument is
* correct for bounds-checking.
*/
const char *
tok2strary_internal(register const char **lp, int n, register const char *fmt,
register int v)
{
static char buf[128];
if (v >= 0 && v < n && lp[v] != NULL)
return lp[v];
if (fmt == NULL)
fmt = "#%d";
(void)snprintf(buf, sizeof(buf), fmt, v);
return (buf);
}
/*
* Convert a 32-bit netmask to prefixlen if possible
* the function returns the prefix-len; if plen == -1
* then conversion was not possible;
*/
int
mask2plen(u_int32_t mask)
{
u_int32_t bitmasks[33] = {
0x00000000,
0x80000000, 0xc0000000, 0xe0000000, 0xf0000000,
0xf8000000, 0xfc000000, 0xfe000000, 0xff000000,
0xff800000, 0xffc00000, 0xffe00000, 0xfff00000,
0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000,
0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000,
0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00,
0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0,
0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff
};
int prefix_len = 32;
/* let's see if we can transform the mask into a prefixlen */
while (prefix_len >= 0) {
if (bitmasks[prefix_len] == mask)
break;
prefix_len--;
}
return (prefix_len);
}
#ifdef INET6
int
mask62plen(const u_char *mask)
{
u_char bitmasks[9] = {
0x00,
0x80, 0xc0, 0xe0, 0xf0,
0xf8, 0xfc, 0xfe, 0xff
};
int byte;
int cidr_len = 0;
for (byte = 0; byte < 16; byte++) {
u_int bits;
for (bits = 0; bits < (sizeof (bitmasks) / sizeof (bitmasks[0])); bits++) {
if (mask[byte] == bitmasks[bits]) {
cidr_len += bits;
break;
}
}
if (mask[byte] != 0xff)
break;
}
return (cidr_len);
}
#endif /* INET6 */
/* VARARGS */
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 */
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.
*/
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;
}
/*
* On Windows, we need to open the file in binary mode, so that
* we get all the bytes specified by the size we get from "fstat()".
* On UNIX, that's not necessary. O_BINARY is defined on Windows;
* we define it as 0 if it's not defined, so it does nothing.
*/
#ifndef O_BINARY
#define O_BINARY 0
#endif
char *
read_infile(char *fname)
{
register int i, fd, cc;
register char *cp;
struct stat buf;
fd = open(fname, O_RDONLY|O_BINARY);
if (fd < 0)
error("can't open %s: %s", fname, pcap_strerror(errno));
if (fstat(fd, &buf) < 0)
error("can't stat %s: %s", fname, pcap_strerror(errno));
cp = malloc((u_int)buf.st_size + 1);
if (cp == NULL)
error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
fname, pcap_strerror(errno));
cc = read(fd, cp, (u_int)buf.st_size);
if (cc < 0)
error("read %s: %s", fname, pcap_strerror(errno));
if (cc != buf.st_size)
error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
close(fd);
/* replace "# comment" with spaces */
for (i = 0; i < cc; i++) {
if (cp[i] == '#')
while (i < cc && cp[i] != '\n')
cp[i++] = ' ';
}
cp[cc] = '\0';
return (cp);
}
void
safeputs(const char *s, int maxlen)
{
int idx = 0;
while (*s && idx < maxlen) {
safeputchar(*s);
idx++;
s++;
}
}
void
safeputchar(int c)
{
unsigned char ch;
ch = (unsigned char)(c & 0xff);
if (ch < 0x80 && isprint(ch))
printf("%c", ch);
else
printf("\\0x%02x", ch);
}