utils.c

/* $Id$ */

/*
 *   Copyright (c) 2001-2010 Aaron Turner <aturner at synfin dot net>
 *   Copyright (c) 2013-2022 Fred Klassen <tcpreplay at appneta dot com> - AppNeta
 *
 *   The Tcpreplay Suite of tools is free software: you can redistribute it 
 *   and/or modify it under the terms of the GNU General Public License as 
 *   published by the Free Software Foundation, either version 3 of the 
 *   License, or with the authors permission any later version.
 *
 *   The Tcpreplay Suite is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with the Tcpreplay Suite.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"
#include "defines.h"
#include "common.h"

#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <ctype.h>
#include <unistd.h>

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#ifdef DEBUG
extern int debug;
#endif

/**
 * this is wrapped up in a #define safe_malloc
 * This function, detects failures to malloc memory and zeros out the
 * memory before returning
 */

void *
_our_safe_malloc(size_t len, const char *funcname, const int line, const char *file)
{
    u_char *ptr;

    if ((ptr = malloc(len)) == NULL) {
        fprintf(stderr, "ERROR in %s:%s() line %d: Unable to malloc() %zu bytes/n",
                file, funcname, line, len);
        exit(-1);
    }

    /* zero memory */
    memset(ptr, 0, len);

    /* wrapped inside an #ifdef for better performance */
    dbgx(5, "Malloc'd %zu bytes in %s:%s() line %d", len, file, funcname, line);

    return (void *)ptr;
}

/**
 * this is wrapped up in a #define safe_realloc
 * This function, detects failures to realloc memory and zeros
 * out the NEW memory if len > current len.  As always, remember
 * to use it as:
 * ptr = safe_realloc(ptr, size)
 */
void *
_our_safe_realloc(void *ptr, size_t len, const char *funcname, const int line, const char *file)
{

    if ((ptr = realloc(ptr, len)) == NULL) {
        fprintf(stderr, "ERROR: in %s:%s() line %d: Unable to remalloc() buffer to %zu bytes", file, funcname, line, len);
        exit(-1);
    }

    dbgx(5, "Remalloc'd buffer to %zu bytes in %s:%s() line %d", len, file, funcname, line);

    return ptr;
}

/**
 * this is wrapped up in a #define safe_strdup
 * This function, detects failures to realloc memory
 */
char *
_our_safe_strdup(const char *str, const char *funcname, const int line, const char *file)
{
    char *newstr;

    if ((newstr = (char *)malloc(strlen(str) + 1)) == NULL) {
        fprintf(stderr, "ERROR in %s:%s() line %d: Unable to strdup() %zu bytes\n", file, funcname, line, strlen(str));
        exit(-1);
    }

    memcpy(newstr, str, strlen(str) + 1);

    return newstr;

}

/**
 * calls free and sets to NULL.
 */
void
_our_safe_free(void *ptr, const char *funcname, const int line, const char *file)
{
    assert(funcname);
    assert(line);
    assert(file);

    if (ptr == NULL)
        return;

    free(ptr);
}

/**
 * get next packet in pcap file
 */
u_char *_our_safe_pcap_next(pcap_t *pcap,  struct pcap_pkthdr *pkthdr,
        const char *funcname, const int line, const char *file)
{
    u_char *pktdata = (u_char *)pcap_next(pcap, pkthdr);

    if (pktdata) {
        if (pkthdr->len > MAX_SNAPLEN) {
            fprintf(stderr, "safe_pcap_next ERROR: Invalid packet length in %s:%s() line %d: %u is greater than maximum %u\n",
                    file, funcname, line, pkthdr->len, MAX_SNAPLEN);
            exit(-1);
        }

        if (!pkthdr->len || !pkthdr->caplen) {
            fprintf(stderr, "safe_pcap_next ERROR: Invalid packet length in %s:%s() line %d: packet length=%u capture length=%u\n",
                    file, funcname, line, pkthdr->len, pkthdr->caplen);
            exit(-1);
        }

        /* attempt to correct invalid captures */
        if (pkthdr->len < pkthdr->caplen) {
            dbgx(1, "Correcting invalid packet capture length %d: packet length=%u",
                    pkthdr->caplen, pkthdr->len);
            pkthdr->caplen = pkthdr->len;
        }
    } else {
        /* this will be reported as a failed packet in final report */
        dbg(1, "No data found in packet");
    }

    return pktdata;
}

/**
 * get next packet in pcap file (extended)
 */
int _our_safe_pcap_next_ex(pcap_t *pcap, struct pcap_pkthdr **pkthdr,
        const u_char **pktdata, const char *funcname,
        const int line, const char *file)
{
    int res = pcap_next_ex(pcap, pkthdr, pktdata);

    if (*pktdata && *pkthdr) {
        if ((*pkthdr)->len > MAXPACKET) {
            fprintf(stderr, "safe_pcap_next_ex ERROR: Invalid packet length in %s:%s() line %d: %u is greater than maximum %u\n",
                    file, funcname, line, (*pkthdr)->len, MAXPACKET);
            exit(-1);
        }

        if (!(*pkthdr)->len || (*pkthdr)->len < (*pkthdr)->caplen) {
            fprintf(stderr, "safe_pcap_next_ex ERROR: Invalid packet length in %s:%s() line %d: packet length=%u capture length=%u\n",
                    file, funcname, line, (*pkthdr)->len, (*pkthdr)->caplen);
            exit(-1);
        }

        if ((*pkthdr)->len < (*pkthdr)->caplen) {
            dbgx(1, "Correcting invalid packet capture length %d: packet length=%u",
                    (*pkthdr)->caplen, (*pkthdr)->len);
            (*pkthdr)->caplen = (*pkthdr)->len;
        }
    } else {
        /* this will be reported as a failed packet in final report */
        dbgx(1, "No data found in packet 0x%p and/or header 0x%p",
                *pktdata, *pkthdr);
    }

    return res;
}

/**
 * Print various packet statistics
 */
void
packet_stats(const tcpreplay_stats_t *stats)
{
    struct timeval diff;
    COUNTER diff_us;
    COUNTER bytes_sec = 0;
    u_int32_t bytes_sec_10ths = 0;
    COUNTER mb_sec = 0;
    u_int32_t mb_sec_100ths = 0;
    u_int32_t mb_sec_1000ths = 0;
    COUNTER pkts_sec = 0;
    u_int32_t pkts_sec_100ths = 0;

    timersub(&stats->end_time, &stats->start_time, &diff);
    diff_us = TIMEVAL_TO_MICROSEC(&diff);

    if (diff_us && stats->pkts_sent && stats->bytes_sent) {
        COUNTER bytes_sec_X10;
        COUNTER pkts_sec_X100;
        COUNTER mb_sec_X1000;
        COUNTER mb_sec_X100;

        if (stats->bytes_sent > 1000 * 1000 * 1000 && diff_us > 1000 * 1000) {
            bytes_sec_X10 = (stats->bytes_sent * 10 * 1000) / (diff_us / 1000);
            pkts_sec_X100 = (stats->pkts_sent * 100 * 1000) / (diff_us / 1000);
         } else {
            bytes_sec_X10 = (stats->bytes_sent * 10 * 1000 * 1000) / diff_us;
            pkts_sec_X100 = (stats->pkts_sent * 100 * 1000 * 1000) / diff_us;
         }

        bytes_sec = bytes_sec_X10 / 10;
        bytes_sec_10ths = bytes_sec_X10 % 10;

        mb_sec_X1000 = (bytes_sec * 8) / 1000;
        mb_sec_X100 = mb_sec_X1000 / 10;
        mb_sec = mb_sec_X1000 / 1000;
        mb_sec_100ths = mb_sec_X100 % 100;
        mb_sec_1000ths = mb_sec_X1000 % 1000;

        pkts_sec = pkts_sec_X100 / 100;
        pkts_sec_100ths = pkts_sec_X100 % 100;
    }

    if (diff_us >= 1000 * 1000)
        printf("Actual: " COUNTER_SPEC " packets (" COUNTER_SPEC " bytes) sent in %zd.%02zd seconds\n",
                stats->pkts_sent, stats->bytes_sent, (ssize_t)diff.tv_sec, (ssize_t)(diff.tv_usec / (10 * 1000)));
    else
        printf("Actual: " COUNTER_SPEC " packets (" COUNTER_SPEC " bytes) sent in %zd.%06zd seconds\n",
                stats->pkts_sent, stats->bytes_sent, (ssize_t)diff.tv_sec, (ssize_t)diff.tv_usec);


    if (mb_sec >= 1)
        printf("Rated: %llu.%1u Bps, %llu.%02u Mbps, %llu.%02u pps\n",
               bytes_sec, bytes_sec_10ths, mb_sec, mb_sec_100ths, pkts_sec, pkts_sec_100ths);
    else
        printf("Rated: %llu.%1u Bps, %llu.%03u Mbps, %llu.%02u pps\n",
               bytes_sec, bytes_sec_10ths, mb_sec, mb_sec_1000ths, pkts_sec, pkts_sec_100ths);
    fflush(NULL);
    
    if (stats->failed)
        printf("Failed write attempts: " COUNTER_SPEC "\n",
                stats->failed);
}

/**
 * fills a buffer with a string representing the given time
 *
 * @param when: the time that should be formatted
 * @param buf: a buffer to write to
 * @param len: length of the buffer
 * @return: string containing date, or -1 on error
 */
int format_date_time(struct timeval *when, char *buf, size_t len)
{
    struct tm *tm;
    char tmp[64];

    assert(len);

    tm = localtime(&when->tv_sec);
    if (!tm)
        return -1;

    strftime(tmp, sizeof tmp, "%Y-%m-%d %H:%M:%S.%%06u", tm);
    return snprintf(buf, len, tmp, when->tv_usec);
}

/**
 * reads a hexstring in the format of xx,xx,xx,xx spits it back into *hex
 * up to hexlen bytes.  Returns actual number of bytes returned.  On error
 * it just calls errx() since all errors are fatal.
 */
int
read_hexstring(const char *l2string, u_char *hex, const int hexlen)
{
    int numbytes = 0;
    unsigned int value;
    char *l2byte;
    u_char databyte;
    char *token = NULL;
    char *string;

    string = safe_strdup(l2string);

    if (hexlen <= 0)
        err(-1, "Hex buffer must be > 0");

    memset(hex, '\0', hexlen);

    /* data is hex, comma separated, byte by byte */

    /* get the first byte */
    l2byte = strtok_r(string, ",", &token);
    sscanf(l2byte, "%x", &value);
    if (value > 0xff)
        errx(-1, "Invalid hex string byte: %s", l2byte);
    databyte = (u_char) value;
    memcpy(&hex[numbytes], &databyte, 1);

    /* get remaining bytes */
    while ((l2byte = strtok_r(NULL, ",", &token)) != NULL) {
        numbytes++;
        if (numbytes + 1 > hexlen) {
            warn("Hex buffer too small for data- skipping data");
            goto done;
        }
        sscanf(l2byte, "%x", &value);
        if (value > 0xff)
            errx(-1, "Invalid hex string byte: %s", l2byte);
        databyte = (u_char) value;
        memcpy(&hex[numbytes], &databyte, 1);
    }

    numbytes++;

done:
    safe_free(string);

    dbgx(1, "Read %d bytes of hex data", numbytes);
    return (numbytes);
}

#ifdef USE_CUSTOM_INET_ATON
int
inet_aton(const char *name, struct in_addr *addr)
{
    in_addr_t a = inet_addr(name);
    addr->s_addr = a;
    return a != (in_addr_t)-1;
}
#endif

#if SIZEOF_LONG  == 4
uint32_t __div64_32(uint64_t *n, uint32_t base)
{
    uint64_t rem = *n;
    uint64_t b = base;
    uint64_t res, d = 1;
    uint32_t high = rem >> 32;

    /* Reduce the thing a bit first */
    res = 0;
    if (high >= base) {
        high /= base;
        res = (uint64_t) high << 32;
        rem -= (uint64_t) (high*base) << 32;
    }

    while ((int64_t)b > 0 && b < rem) {
        b = b+b;
        d = d+d;
    }

    do {
        if (rem >= b) {
            rem -= b;
            res += d;
        }
        b >>= 1;
        d >>= 1;
    } while (d);

    *n = res;
    return rem;
}
#endif /* SIZEOF_LONG  == 4 */

/**
 * Implementation of rand_r that is consistent across all platforms
 * This algorithm is mentioned in the ISO C standard, here extended
 * for 32 bits.
 * @param: seed
 * @return: random number
 */
uint32_t tcpr_random(uint32_t *seed)
{
  unsigned int next = *seed;
  int result;

  next *= 1103515245;
  next += 12345;
  result = (unsigned int) (next / 65536) % 2048;

  next *= 1103515245;
  next += 12345;
  result <<= 10;
  result ^= (unsigned int) (next / 65536) % 1024;

  next *= 1103515245;
  next += 12345;
  result <<= 10;
  result ^= (unsigned int) (next / 65536) % 1024;

  *seed = next;

  return result;
}

/**
 * #416 - Ensure STDIN is not left in non-blocking mode after closing
 * a program. BSD and Unix derivatives should utilize `FIONBIO` due to known
 * issues with reading from tty with a 0 byte read returning -1 opposed to 0.
 */
void restore_stdin(void)
{
#ifdef FIONBIO
    int nb = 0;

    ioctl(0, FIONBIO, &nb);
#else
    fcntl(0, F_SETFL, fcntl(0, F_GETFL) | O_NONBLOCK);
#endif /* FIONBIO */
}