source: network-demos/ttcp/ttcp_orig/ttcp.c @ 5ee0701

/*
 *      T T C P . C
 *
 * Test TCP connection.  Makes a connection on port 5001
 * and transfers fabricated buffers or data copied from stdin.
 *
 * Usable on 4.2, 4.3, and 4.1a systems by defining one of
 * BSD42 BSD43 (BSD41a)
 * Machines using System V with BSD sockets should define SYSV.
 *
 * Modified for operation under 4.2BSD, 18 Dec 84
 *      T.C. Slattery, USNA
 * Minor improvements, Mike Muuss and Terry Slattery, 16-Oct-85.
 * Modified in 1989 at Silicon Graphics, Inc.
 *      catch SIGPIPE to be able to print stats when receiver has died 
 *      for tcp, don't look for sentinel during reads to allow small transfers
 *      increased default buffer size to 8K, nbuf to 2K to transfer 16MB
 *      moved default port to 5001, beyond IPPORT_USERRESERVED
 *      make sinkmode default because it is more popular, 
 *              -s now means don't sink/source 
 *      count number of read/write system calls to see effects of 
 *              blocking from full socket buffers
 *      for tcp, -D option turns off buffered writes (sets TCP_NODELAY sockopt)
 *      buffer alignment options, -A and -O
 *      print stats in a format that's a bit easier to use with grep & awk
 *      for SYSV, mimic BSD routines to use most of the existing timing code
 * Modified by Steve Miller of the University of Maryland, College Park
 *      -b sets the socket buffer size (SO_SNDBUF/SO_RCVBUF)
 * Modified Sept. 1989 at Silicon Graphics, Inc.
 *      restored -s sense at request of tcs@brl
 * Modified Oct. 1991 at Silicon Graphics, Inc.
 *      use getopt(3) for option processing, add -f and -T options.
 *      SGI IRIX 3.3 and 4.0 releases don't need #define SYSV.
 *
 * Distribution Status -
 *      Public Domain.  Distribution Unlimited.
 *
 *  $Id$
 */

#ifndef lint
/* static char RCSid[] = "ttcp.c $Revision$"; */
#endif

#define BSD43
/* #define BSD42 */
/* #define BSD41a */
/* #define SYSV */      /* required on SGI IRIX releases before 3.3 */

#define ENABLE_NANOSLEEP_DELAY

#include <stdio.h>
#include <signal.h>
#include <ctype.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <sys/time.h>           /* struct timeval */

#include <unistd.h>
#include <stdlib.h>

#if defined(SYSV)
#include <sys/times.h>
#include <sys/param.h>
struct rusage {
    struct timeval ru_utime, ru_stime;
};
#define RUSAGE_SELF 0
#else
#include <sys/resource.h>
#endif

struct sockaddr_in sinme;
struct sockaddr_in sinhim;
struct sockaddr_in frominet;

/* these make it easier to avoid warnings */
struct sockaddr *sinhim_p = (struct sockaddr *) &sinhim;
struct sockaddr *sinme_p = (struct sockaddr *) &sinme;
struct sockaddr *frominet_p = (struct sockaddr *) &frominet;

int domain;
socklen_t fromlen;
int fd;                         /* fd of network socket */

int buflen = 8 * 1024;          /* length of buffer */
char *buf;                      /* ptr to dynamic buffer */
int nbuf = 2 * 1024;            /* number of buffers to send in sinkmode */

int bufoffset = 0;              /* align buffer to this */
int bufalign = 16*1024;         /* modulo this */

int udp = 0;                    /* 0 = tcp, !0 = udp */
int options = 0;                /* socket options */
int one = 1;                    /* for 4.3 BSD style setsockopt() */
short port = 5001;              /* TCP port number */
char *host;                     /* ptr to name of host */
int trans;                      /* 0=receive, !0=transmit mode */
int sinkmode = 0;               /* 0=normal I/O, !0=sink/source mode */
int verbose = 0;                /* 0=print basic info, 1=print cpu rate, proc
                                 * resource usage. */
int nodelay = 0;                /* set TCP_NODELAY socket option */
int b_flag = 0;                 /* use mread() */
int sockbufsize = 0;            /* socket buffer size to use */
char fmt = 'K';                 /* output format: k = kilobits, K = kilobytes,
                                 *  m = megabits, M = megabytes, 
                                 *  g = gigabits, G = gigabytes */
int touchdata = 0;              /* access data after reading */
long milliseconds = 0;          /* delay in milliseconds */

struct hostent *addr;
extern int errno;
extern int optind;
extern char *optarg;

char Usage[] = "\
Usage: ttcp -t [-options] host [ < in ]\n\
       ttcp -r [-options > out]\n\
Common options:\n\
        -l ##   length of bufs read from or written to network (default 8192)\n\
        -u      use UDP instead of TCP\n\
        -p ##   port number to send to or listen at (default 5001)\n\
        -s      -t: source a pattern to network\n\
                -r: sink (discard) all data from network\n\
        -A      align the start of buffers to this modulus (default 16384)\n\
        -O      start buffers at this offset from the modulus (default 0)\n\
        -v      verbose: print more statistics\n\
        -d      set SO_DEBUG socket option\n\
        -b ##   set socket buffer size (if supported)\n\
        -f X    format for rate: k,K = kilo{bit,byte}; m,M = mega; g,G = giga\n\
Options specific to -t:\n\
        -n##    number of source bufs written to network (default 2048)\n\
        -D      don't buffer TCP writes (sets TCP_NODELAY socket option)\n\
Options specific to -r:\n\
        -B      for -s, only output full blocks as specified by -l (for TAR)\n\
        -T      \"touch\": access each byte as it's read\n\
        -m ##   delay for specified milliseconds between each write\n\
";      

char stats[128];
double nbytes;                  /* bytes on net */
unsigned long numCalls;         /* # of I/O system calls */
double cput, realt;             /* user, real time (seconds) */

void err();
void mes();
void pattern();
void prep_timer();
double read_timer();
int Nread();
int Nwrite();
void delay();
int mread();
char *outfmt();

void
sigpipe()
{
}

void millisleep(long msec)
{
#if defined(ENABLE_NANOSLEEP_DELAY)
  struct timespec req;

  req.tv_sec = msec / 1000;
  req.tv_nsec = (msec % 1000) * 1000000;

  nanosleep( &req, NULL );
#endif
}
int main(argc,argv)
int argc;
char **argv;
{
        unsigned long addr_tmp;
        int c;

        if (argc < 2) goto usage;

        while ((c = getopt(argc, argv, "drstuvBDTb:f:l:m:n:p:A:O:")) != -1) {
                switch (c) {

                case 'B':
                        b_flag = 1;
                        break;
                case 't':
                        trans = 1;
                        break;
                case 'r':
                        trans = 0;
                        break;
                case 'd':
                        options |= SO_DEBUG;
                        break;
                case 'D':
#ifdef TCP_NODELAY
                        nodelay = 1;
#else
                        fprintf(stderr, 
        "ttcp: -D option ignored: TCP_NODELAY socket option not supported\n");
#endif
                        break;
                case 'm':
                        milliseconds = atoi(optarg);
                        #if !defined(ENABLE_NANOSLEEP_DELAY)
                                fprintf(stderr, "millisecond delay disabled\n");
                        #endif
                        break;
                case 'n':
                        nbuf = atoi(optarg);
                        break;
                case 'l':
                        buflen = atoi(optarg);
                        break;
                case 's':
                        sinkmode = !sinkmode;
                        break;
                case 'p':
                        port = atoi(optarg);
                        break;
                case 'u':
                        udp = 1;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                case 'A':
                        bufalign = atoi(optarg);
                        break;
                case 'O':
                        bufoffset = atoi(optarg);
                        break;
                case 'b':
#if defined(SO_SNDBUF) || defined(SO_RCVBUF)
                        sockbufsize = atoi(optarg);
#else
                        fprintf(stderr, 
"ttcp: -b option ignored: SO_SNDBUF/SO_RCVBUF socket options not supported\n");
#endif
                        break;
                case 'f':
                        fmt = *optarg;
                        break;
                case 'T':
                        touchdata = 1;
                        break;

                default:
                        goto usage;
                }
        }
        if(trans)  {
                /* xmitr */
                if (optind == argc)
                        goto usage;
                bzero((char *)&sinhim, sizeof(sinhim));
                host = argv[optind];
                if (atoi(host) > 0 )  {
                        /* Numeric */
                        sinhim.sin_family = AF_INET;
#if defined(cray)
                        addr_tmp = inet_addr(host);
                        sinhim.sin_addr = addr_tmp;
#else
                        sinhim.sin_addr.s_addr = inet_addr(host);
#endif
                } else {
                        if ((addr=gethostbyname(host)) == NULL)
                                err("bad hostname");
                        sinhim.sin_family = addr->h_addrtype;
                        bcopy(addr->h_addr,(char*)&addr_tmp, addr->h_length);
#if defined(cray)
                        sinhim.sin_addr = addr_tmp;
#else
                        sinhim.sin_addr.s_addr = addr_tmp;
#endif /* cray */
                }
                sinhim.sin_port = htons(port);
                sinme.sin_port = 0;             /* free choice */
        } else {
                /* rcvr */
                sinme.sin_port =  htons(port);
        }


        if (udp && buflen < 5) {
            buflen = 5;         /* send more than the sentinel size */
        }

        if ( (buf = (char *)malloc(buflen+bufalign)) == (char *)NULL)
                err("malloc");
        if (bufalign != 0)
                buf +=(bufalign - ((int)buf % bufalign) + bufoffset) % bufalign;

        if (trans) {
            fprintf(stdout,
            "ttcp-t: buflen=%d, nbuf=%d, align=%d/%d, port=%d",
                buflen, nbuf, bufalign, bufoffset, port);
            if (sockbufsize)
                fprintf(stdout, ", sockbufsize=%d", sockbufsize);
            fprintf(stdout, "  %s  -> %s\n", udp?"udp":"tcp", host);
        } else {
            fprintf(stdout,
            "ttcp-r: buflen=%d, nbuf=%d, align=%d/%d, port=%d",
                buflen, nbuf, bufalign, bufoffset, port);
            if (sockbufsize)
                fprintf(stdout, ", sockbufsize=%d", sockbufsize);
            fprintf(stdout, "  %s\n", udp?"udp":"tcp");
        }

        if ((fd = socket(AF_INET, udp?SOCK_DGRAM:SOCK_STREAM, 0)) < 0)
                err("socket");
        mes("socket");

        if (bind(fd, sinme_p, sizeof(sinme)) < 0)
                err("bind");

#if defined(SO_SNDBUF) || defined(SO_RCVBUF)
        if (sockbufsize) {
            if (trans) {
                if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sockbufsize,
                    sizeof sockbufsize) < 0)
                        err("setsockopt: sndbuf");
                mes("sndbuf");
            } else {
                if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &sockbufsize,
                    sizeof sockbufsize) < 0)
                        err("setsockopt: rcvbuf");
                mes("rcvbuf");
            }
        }
#endif

        if (!udp)  {
#if !defined(__rtems__)
            signal(SIGPIPE, sigpipe);
#endif
            if (trans) {
                /* We are the client if transmitting */
                if (options)  {
#if defined(BSD42)
                        if( setsockopt(fd, SOL_SOCKET, options, 0, 0) < 0)
#else /* BSD43 */
                        if( setsockopt(fd, SOL_SOCKET, options, &one, sizeof(one)) < 0)
#endif
                                err("setsockopt");
                }
#ifdef TCP_NODELAY
                if (nodelay) {
                        struct protoent *p;
                        p = getprotobyname("tcp");
                        if( p && setsockopt(fd, p->p_proto, TCP_NODELAY, 
                            &one, sizeof(one)) < 0)
                                err("setsockopt: nodelay");
                        mes("nodelay");
                }
#endif
                if(connect(fd, sinhim_p, sizeof(sinhim) ) < 0)
                        err("connect");
                mes("connect");
            } else {
                /* otherwise, we are the server and 
                 * should listen for the connections
                 */
#if defined(ultrix) || defined(sgi)
                listen(fd,1);   /* workaround for alleged u4.2 bug */
#else
                listen(fd,0);   /* allow a queue of 0 */
#endif
                if(options)  {
#if defined(BSD42)
                        if( setsockopt(fd, SOL_SOCKET, options, 0, 0) < 0)
#else /* BSD43 */
                        if( setsockopt(fd, SOL_SOCKET, options, &one, sizeof(one)) < 0)
#endif
                                err("setsockopt");
                }
                fromlen = sizeof(frominet);
                domain = AF_INET;
                if((fd=accept(fd, frominet_p, &fromlen) ) < 0)
                        err("accept");
                { struct sockaddr_in peer;
                  socklen_t peerlen = sizeof(peer);
                  if (getpeername(fd, (struct sockaddr *) &peer, 
                                &peerlen) < 0) {
                        err("getpeername");
                  }
                  fprintf(stderr,"ttcp-r: accept from %s\n", 
                        inet_ntoa(peer.sin_addr));
                }
            }
        }
        prep_timer();
        errno = 0;
        if (sinkmode) {      
                register int cnt;
                if (trans)  {
                        pattern( buf, buflen );
                        if(udp)  (void)Nwrite( fd, buf, 4 ); /* rcvr start */
                        while (nbuf-- && Nwrite(fd,buf,buflen) == buflen) {
                                nbytes += buflen;
                                millisleep( milliseconds );
                        }
                        if(udp)  (void)Nwrite( fd, buf, 4 ); /* rcvr end */
                } else {
                        if (udp) {
                            while ((cnt=Nread(fd,buf,buflen)) > 0)  {
                                    static int going = 0;
                                    if( cnt <= 4 )  {
                                            if( going )
                                                    break;      /* "EOF" */
                                            going = 1;
                                            prep_timer();
                                    } else {
                                            nbytes += cnt;
                                    }
                            }
                        } else {
                            while ((cnt=Nread(fd,buf,buflen)) > 0)  {
                                    nbytes += cnt;
                            }
                        }
                }
        } else {
                register int cnt;
                if (trans)  {
                        while((cnt=read(0,buf,buflen)) > 0 &&
                            Nwrite(fd,buf,cnt) == cnt)
                                nbytes += cnt;
                }  else  {
                        while((cnt=Nread(fd,buf,buflen)) > 0 &&
                            write(1,buf,cnt) == cnt)
                                nbytes += cnt;
                }
        }
        if(errno) err("IO");
        (void)read_timer(stats,sizeof(stats));
        if(udp&&trans)  {
                (void)Nwrite( fd, buf, 4 ); /* rcvr end */
                (void)Nwrite( fd, buf, 4 ); /* rcvr end */
                (void)Nwrite( fd, buf, 4 ); /* rcvr end */
                (void)Nwrite( fd, buf, 4 ); /* rcvr end */
        }
        if( cput <= 0.0 )  cput = 0.001;
        if( realt <= 0.0 )  realt = 0.001;
        fprintf(stdout,
                "ttcp%s: %.0f bytes in %.2f real seconds = %s/sec +++\n",
                trans?"-t":"-r",
                nbytes, realt, outfmt(nbytes/realt));
        if (verbose) {
            fprintf(stdout,
                "ttcp%s: %.0f bytes in %.2f CPU seconds = %s/cpu sec\n",
                trans?"-t":"-r",
                nbytes, cput, outfmt(nbytes/cput));
        }
        fprintf(stdout,
                "ttcp%s: %ld I/O calls, msec/call = %.2f, calls/sec = %.2f\n",
                trans?"-t":"-r",
                numCalls,
                1024.0 * realt/((double)numCalls),
                ((double)numCalls)/realt);
        fprintf(stdout,"ttcp%s: %s\n", trans?"-t":"-r", stats);
        if (verbose) {
            fprintf(stdout,
                "ttcp%s: buffer address %p\n",
                trans?"-t":"-r",
                buf);
        }
        exit(0);

usage:
        fprintf(stderr,Usage);
        exit(1);
        return 0;
}

void
err(s)
char *s;
{
        fprintf(stderr,"ttcp%s: ", trans?"-t":"-r");
        perror(s);
        fprintf(stderr,"errno=%d\n",errno);
        exit(1);
}

void
mes(s)
char *s;
{
        fprintf(stderr,"ttcp%s: %s\n", trans?"-t":"-r", s);
}

void pattern( cp, cnt )
register char *cp;
register int cnt;
{
        register char c;
        c = 0;
        while( cnt-- > 0 )  {
                while( !isprint((c&0x7F)) )  c++;
                *cp++ = (c++&0x7F);
        }
}

char *
outfmt(b)
double b;
{
    static char obuf[50];
    switch (fmt) {
        case 'G':
            sprintf(obuf, "%.2f GB", b / 1024.0 / 1024.0 / 1024.0);
            break;
        default:
        case 'K':
            sprintf(obuf, "%.2f KB", b / 1024.0);
            break;
        case 'M':
            sprintf(obuf, "%.2f MB", b / 1024.0 / 1024.0);
            break;
        case 'g':
            sprintf(obuf, "%.2f Gbit", b * 8.0 / 1024.0 / 1024.0 / 1024.0);
            break;
        case 'k':
            sprintf(obuf, "%.2f Kbit", b * 8.0 / 1024.0);
            break;
        case 'm':
            sprintf(obuf, "%.2f Mbit", b * 8.0 / 1024.0 / 1024.0);
            break;
    }
    return obuf;
}

static struct   timeval time0;  /* Time at which timing started */
static struct   rusage ru0;     /* Resource utilization at the start */

static void prusage();
static void tvadd();
static void tvsub();
static void psecs();

#if defined(SYSV)
/*ARGSUSED*/
static
getrusage(ignored, ru)
    int ignored;
    register struct rusage *ru;
{
    struct tms buf;

    times(&buf);

    /* Assumption: HZ <= 2147 (LONG_MAX/1000000) */
    ru->ru_stime.tv_sec  = buf.tms_stime / HZ;
    ru->ru_stime.tv_usec = ((buf.tms_stime % HZ) * 1000000) / HZ;
    ru->ru_utime.tv_sec  = buf.tms_utime / HZ;
    ru->ru_utime.tv_usec = ((buf.tms_utime % HZ) * 1000000) / HZ;
}

/*ARGSUSED*/
static 
gettimeofday(tp, zp)
    struct timeval *tp;
    struct timezone *zp;
{
    tp->tv_sec = time(0);
    tp->tv_usec = 0;
}
#endif /* SYSV */

/*
 *                      P R E P _ T I M E R
 */
void
prep_timer()
{
        gettimeofday(&time0, (struct timezone *)0);
        getrusage(RUSAGE_SELF, &ru0);
}

/*
 *                      R E A D _ T I M E R
 * 
 */
double
read_timer(str,len)
char *str;
{
        struct timeval timedol;
        struct rusage ru1;
        struct timeval td;
        struct timeval tend, tstart;
        char line[132];

        getrusage(RUSAGE_SELF, &ru1);
        gettimeofday(&timedol, (struct timezone *)0);
        prusage(&ru0, &ru1, &timedol, &time0, line);
        (void)strncpy( str, line, len );

        /* Get real time */
        tvsub( &td, &timedol, &time0 );
        realt = td.tv_sec + ((double)td.tv_usec) / 1000000;

        /* Get CPU time (user+sys) */
        tvadd( &tend, &ru1.ru_utime, &ru1.ru_stime );
        tvadd( &tstart, &ru0.ru_utime, &ru0.ru_stime );
        tvsub( &td, &tend, &tstart );
        cput = td.tv_sec + ((double)td.tv_usec) / 1000000;
        if( cput < 0.00001 )  cput = 0.00001;
        return( cput );
}

static void
prusage(r0, r1, e, b, outp)
        register struct rusage *r0, *r1;
        struct timeval *e, *b;
        char *outp;
{
        struct timeval tdiff;
        register time_t t;
        register char *cp;
        register int i;
        int ms;

        t = (r1->ru_utime.tv_sec-r0->ru_utime.tv_sec)*100+
            (r1->ru_utime.tv_usec-r0->ru_utime.tv_usec)/10000+
            (r1->ru_stime.tv_sec-r0->ru_stime.tv_sec)*100+
            (r1->ru_stime.tv_usec-r0->ru_stime.tv_usec)/10000;
        ms =  (e->tv_sec-b->tv_sec)*100 + (e->tv_usec-b->tv_usec)/10000;

#define END(x)  {while(*x) x++;}
#if defined(SYSV)
        cp = "%Uuser %Ssys %Ereal %P";
#else
#if defined(sgi)                /* IRIX 3.3 will show 0 for %M,%F,%R,%C */
        cp = "%Uuser %Ssys %Ereal %P %Mmaxrss %F+%Rpf %Ccsw";
#else
        cp = "%Uuser %Ssys %Ereal %P %Xi+%Dd %Mmaxrss %F+%Rpf %Ccsw";
#endif
#endif
        for (; *cp; cp++)  {
                if (*cp != '%')
                        *outp++ = *cp;
                else if (cp[1]) switch(*++cp) {

                case 'U':
                        tvsub(&tdiff, &r1->ru_utime, &r0->ru_utime);
                        sprintf(outp,"%ld.%01ld", tdiff.tv_sec, tdiff.tv_usec/100000);
                        END(outp);
                        break;

                case 'S':
                        tvsub(&tdiff, &r1->ru_stime, &r0->ru_stime);
                        sprintf(outp,"%ld.%01ld", tdiff.tv_sec, tdiff.tv_usec/100000);
                        END(outp);
                        break;

                case 'E':
                        psecs(ms / 100, outp);
                        END(outp);
                        break;

                case 'P':
                        sprintf(outp,"%d%%", (int) (t*100 / ((ms ? ms : 1))));
                        END(outp);
                        break;

#if !defined(SYSV)
                case 'W':
                        i = r1->ru_nswap - r0->ru_nswap;
                        sprintf(outp,"%d", i);
                        END(outp);
                        break;

                case 'X':
                        sprintf(outp,"%ld", t == 0 ? 0 : (r1->ru_ixrss-r0->ru_ixrss)/t);
                        END(outp);
                        break;

                case 'D':
                        sprintf(outp,"%ld", t == 0 ? 0 :
                            (r1->ru_idrss+r1->ru_isrss-(r0->ru_idrss+r0->ru_isrss))/t);
                        END(outp);
                        break;

                case 'K':
                        sprintf(outp,"%ld", t == 0 ? 0 :
                            ((r1->ru_ixrss+r1->ru_isrss+r1->ru_idrss) -
                            (r0->ru_ixrss+r0->ru_idrss+r0->ru_isrss))/t);
                        END(outp);
                        break;

                case 'M':
                        sprintf(outp,"%d", r1->ru_maxrss/2);
                        END(outp);
                        break;

                case 'F':
                        sprintf(outp,"%d", r1->ru_majflt-r0->ru_majflt);
                        END(outp);
                        break;

                case 'R':
                        sprintf(outp,"%d", r1->ru_minflt-r0->ru_minflt);
                        END(outp);
                        break;

                case 'I':
                        sprintf(outp,"%d", r1->ru_inblock-r0->ru_inblock);
                        END(outp);
                        break;

                case 'O':
                        sprintf(outp,"%d", r1->ru_oublock-r0->ru_oublock);
                        END(outp);
                        break;
                case 'C':
                        sprintf(outp,"%d+%d", r1->ru_nvcsw-r0->ru_nvcsw,
                                r1->ru_nivcsw-r0->ru_nivcsw );
                        END(outp);
                        break;
#endif /* !SYSV */
                }
        }
        *outp = '\0';
}

static void
tvadd(tsum, t0, t1)
        struct timeval *tsum, *t0, *t1;
{

        tsum->tv_sec = t0->tv_sec + t1->tv_sec;
        tsum->tv_usec = t0->tv_usec + t1->tv_usec;
        if (tsum->tv_usec > 1000000)
                tsum->tv_sec++, tsum->tv_usec -= 1000000;
}

static void
tvsub(tdiff, t1, t0)
        struct timeval *tdiff, *t1, *t0;
{

        tdiff->tv_sec = t1->tv_sec - t0->tv_sec;
        tdiff->tv_usec = t1->tv_usec - t0->tv_usec;
        if (tdiff->tv_usec < 0)
                tdiff->tv_sec--, tdiff->tv_usec += 1000000;
}

static void
psecs(l,cp)
long l;
register char *cp;
{
        register int i;

        i = l / 3600;
        if (i) {
                sprintf(cp,"%d:", i);
                END(cp);
                i = l % 3600;
                sprintf(cp,"%d%d", (i/60) / 10, (i/60) % 10);
                END(cp);
        } else {
                i = l;
                sprintf(cp,"%d", i / 60);
                END(cp);
        }
        i %= 60;
        *cp++ = ':';
        sprintf(cp,"%d%d", i / 10, i % 10);
}

/*
 *                      N R E A D
 */
int Nread( fd, buf, count )
int fd;
void *buf;
int count;
{
        struct sockaddr_in from;
        socklen_t len = sizeof(from);
        register int cnt;
        if( udp )  {
                cnt = recvfrom( fd, buf, count, 0, (struct sockaddr *)&from, &len );
                numCalls++;
        } else {
                if( b_flag )
                        cnt = mread( fd, buf, count );  /* fill buf */
                else {
                        cnt = read( fd, buf, count );
                        numCalls++;
                }
                if (touchdata && cnt > 0) {
                        register int c = cnt, sum;
                        register char *b = buf;
                        while (c--)
                                sum += *b++;
                }
        }
        return(cnt);
}

/*
 *                      N W R I T E
 */
int Nwrite( fd, buf, count )
int fd;
void *buf;
int count;
{
        register int cnt;
        if( udp )  {
again:
                cnt = sendto( fd, buf, count, 0, sinhim_p, sizeof(sinhim) );
                numCalls++;
                if( cnt<0 && errno == ENOBUFS )  {
                        printf("ttcp: out of buffers -- delaying\n"); /*JRS*/
                        delay(18000);
                        errno = 0;
                        goto again;
                }
        } else {
                cnt = write( fd, buf, count );
                numCalls++;
        }
        return(cnt);
}

void
delay(us)
{
        struct timeval tv;

        tv.tv_sec = 0;
        tv.tv_usec = us;
        (void)select( 1, (fd_set *)0, (fd_set *)0, (fd_set *)0, &tv );
}

/*
 *                      M R E A D
 *
 * This function performs the function of a read(II) but will
 * call read(II) multiple times in order to get the requested
 * number of characters.  This can be necessary because
 * network connections don't deliver data with the same
 * grouping as it is written with.  Written by Robert S. Miles, BRL.
 */
int
mread(fd, bufp, n)
int fd;
register char   *bufp;
unsigned        n;
{
        register unsigned       count = 0;
        register int            nread;

        do {
                nread = read(fd, bufp, n-count);
                numCalls++;
                if(nread < 0)  {
                        perror("ttcp_mread");
                        return(-1);
                }
                if(nread == 0)
                        return((int)count);
                count += (unsigned)nread;
                bufp += nread;
         } while(count < n);

        return((int)count);
}