[tcpdump] / util.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.
 */

#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include <sys/stat.h>

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#include "interface.h"

/*
 * 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(netdissect_options *ndo,
         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 (!ND_ISASCII(c)) {
                        c = ND_TOASCII(c);
                        ND_PRINT((ndo, "M-"));
                }
                if (!ND_ISPRINT(c)) {
                        c ^= 0x40;      /* DEL to ?, others to alpha */
                        ND_PRINT((ndo, "^"));
                }
                ND_PRINT((ndo, "%c", 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(netdissect_options *ndo,
          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 (!ND_ISASCII(c)) {
                        c = ND_TOASCII(c);
                        ND_PRINT((ndo, "M-"));
                }
                if (!ND_ISPRINT(c)) {
                        c ^= 0x40;      /* DEL to ?, others to alpha */
                        ND_PRINT((ndo, "^"));
                }
                ND_PRINT((ndo, "%c", 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(netdissect_options *ndo,
           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 (!ND_ISASCII(c)) {
                        c = ND_TOASCII(c);
                        ND_PRINT((ndo, "M-"));
                }
                if (!ND_ISPRINT(c)) {
                        c ^= 0x40;      /* DEL to ?, others to alpha */
                        ND_PRINT((ndo, "^"));
                }
                ND_PRINT((ndo, "%c", c));
        }
        return (n == 0) ? 0 : ret;
}

/*
 * Format the timestamp
 */
static 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(netdissect_options *ndo,
         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 (ndo->ndo_tflag) {

        case 0: /* Default */
                s = (tvp->tv_sec + thiszone) % 86400;
                ND_PRINT((ndo, "%s ", ts_format(s, tvp->tv_usec)));
                break;

        case 1: /* No time stamp */
                break;

        case 2: /* Unix timeval style */
                ND_PRINT((ndo, "%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--;
                }

                ND_PRINT((ndo, "%s ", ts_format(d_sec, d_usec)));

                if (ndo->ndo_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)
                        ND_PRINT((ndo, "Date fail  "));
                else
                        ND_PRINT((ndo, "%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(netdissect_options *ndo,
            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) {
                ND_PRINT((ndo, "0s"));
                return;
        }
        if (secs < 0) {
                ND_PRINT((ndo, "-"));
                secs = -secs;
        }
        while (secs > 0) {
                if (secs >= *s) {
                        ND_PRINT((ndo, "%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(netdissect_options *ndo, const u_char *cp,const char *ident,int len)
{
        if (len < 0) {
          ND_PRINT((ndo,"%sDissector error: print_unknown_data called with negative length",
                    ident));
                return(0);
        }
        if (ndo->ndo_snapend - cp < len)
                len = ndo->ndo_snapend - cp;
        if (len < 0) {
          ND_PRINT((ndo,"%sDissector error: print_unknown_data called with pointer past end of packet",
                    ident));
                return(0);
        }
        hex_print(ndo, 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 u_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 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(uint32_t mask)
{
        uint32_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(netdissect_options *ndo,
         const u_char *s, const u_int maxlen)
{
        u_int idx = 0;

        while (*s && idx < maxlen) {
                safeputchar(ndo, *s);
                idx++;
                s++;
        }
}

void
safeputchar(netdissect_options *ndo,
            const u_char c)
{
        ND_PRINT((ndo, (c < 0x80 && ND_ISPRINT(c)) ? "%c" : "\\0x%02x", c));
}

#ifdef LBL_ALIGN
/*
 * Some compilers try to optimize memcpy(), using the alignment constraint
 * on the argument pointer type.  by using this function, we try to avoid the
 * optimization.
 */
void
unaligned_memcpy(void *p, const void *q, size_t l)
{
        memcpy(p, q, l);
}

/* As with memcpy(), so with memcmp(). */
int
unaligned_memcmp(const void *p, const void *q, size_t l)
{
        return (memcmp(p, q, l));
}
#endif