www.pudn.com > slow.zip > main.C

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	main.c 
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/* Modem for MIPS   AJF	  January 1995 
   Main program */ 
 
#include  
#include  
#include  
#include  
 
#include  
#include  
#include  
#include  
 
#include "modem.h" 
 
#define TOFN "/dev/ttyd2" 
 
global int numpages; 
global uint options, bitrates; 
global vmode veemode; 
 
struct vminfo 
  { char *s; 
    vmode v; 
  }; 
 
static vminfo vmodes[] = 
  { { "-V21o", V21o }, { "-V21a", V21a }, { "-V23o", V23o }, { "-V23a", V23a }, 
    { "-V32o", V32o }, { "-V34o", V34o }, 
    { NULL, (vmode) 0 },	/* terminator */ 
  }; 
 
static char *telno; 
 
static void newhandler(), catchsignal(int), sighandler(int); 
static bool legaltelno(char*); 
static void setoptions(char**); 
static uint bitrate(int), legalbps(vmode); 
static void checkoptions(), usage(int); 
static void seizeline(), sendanswer(); 
 
inline bool isdigit(char ch) { return (ch >= '0') && (ch <= '9'); } 
 
 
global void main(int argc, char **argv) 
  { set_new_handler(newhandler); 
    catchsignal(SIGINT); catchsignal(SIGTERM); 
    catchsignal(SIGUSR1); catchsignal(SIGABRT); 
    setoptions(argv); 
    checkoptions(); 
    if ((options & opt_org) && !legaltelno(telno)) giveup("Illegal telephone number"); 
    if (options & opt_mod) 
      { uint b = legalbps(veemode); 
	unless (options & opt_bps) bitrates = b;	/* default is the full set */ 
	if (bitrates & ~b) giveup("illegal mode-bitrate combination"); 
      } 
    if (options & opt_fax) 
      { initdoc(); 
	if (options & opt_org) readdoc();		/* read whole doc before time-critical part */ 
      } 
    openaudio(); atexit(closeaudio); 
    seizeline(); 
    if (options & opt_org) dialnumber(telno); 
    if (options & (opt_fax | opt_mod)) 
      { if (options & opt_org) waitfortone(CONN_TONE);	/* wait for answer (connect) tone */ 
	if (options & opt_ans) sendanswer();		/* send answer tone */ 
	int contime = time(NULL); 
	infomsg("Connected"); 
	if (options & opt_v8) startsession();		/* V.8 procedures */ 
	if (options & opt_fax) becomefax(); 
	if (options & opt_mod) becomemodem(); 
	infomsg("Call duration: %d secs", time(NULL) - contime); 
      } 
    if ((options & opt_fax) && !(options & opt_org)) writedoc();  /* write whole doc after time-critical part */ 
    exit(0); 
  } 
 
static void newhandler() 
  { giveup("No room"); 
  } 
 
static void catchsignal(int sig) 
  { signal(sig, (SIG_PF) sighandler); 
  } 
 
static void sighandler(int sig) 
  { switch (sig) 
      { default: 
	    giveup("Killed by signal %d.", sig); 
 
	case SIGUSR1: 
	    giveup("Remote modem is not responding."); 
      } 
  } 
 
static bool legaltelno(char *vec) 
  { int n = 0; 
    char *dstr = "0123456789*#ABCD"; 
    if (vec[n] == '+' || vec[n] == '=') n++; 
    until (vec[n] == '\0' || strchr(dstr, vec[n]) == NULL) n++; 
    return (n <= 20 && vec[n] == '\0'); 
  } 
 
static void setoptions(char **argv) 
  { int ap = 0; 
    unless (argv[ap] == NULL) ap++; 
    options = bitrates = 0; 
    until (argv[ap] == NULL) 
      { char *s = argv[ap++]; 
	if (s[0] == '+' || s[0] == '=') 
	  { if (options & opt_org) usage(1); 
	    telno = s; options |= opt_org; 
	  } 
	else if (seq(s, "-ans")) options |= opt_ans; 
	else if (seq(s, "-fax")) options |= opt_fax; 
	else if (seq(s, "-bps")) 
	  { while (argv[ap] != NULL && isdigit(argv[ap][0])) 
	      { int bps = atoi(argv[ap++]); 
		bitrates |= bitrate(bps); 
	      } 
	    options |= opt_bps; 
	  } 
	else if (seq(s,"-V8")) options |= opt_v8; 
	else 
	  { int k = 0; 
	    unless (s[k++] == '-') usage(2); 
	    if (s[k] == 'V') 
	      { if (options & opt_mod) usage(3); 
		int m = 0; 
		until (vmodes[m].s == NULL || seq(vmodes[m].s, s)) m++; 
		if (vmodes[m].s == NULL) usage(4); 
		veemode = vmodes[m].v; 
		options |= opt_mod; 
		if (veemode == V34o) options |= opt_v8;	    /* V.34 requires V.8 */ 
	      } 
	    else 
	      { until (s[k] == '\0') 
		  { char ch = s[k++]; 
		    if (ch == 'v') options |= opt_v; 
		    else usage(5); 
		  } 
	      } 
	  } 
      } 
  } 
 
static uint bitrate(int n) 
  { /* see bitrates.h */ 
    unless (n >= 2400 && n <= 28800 && n%2400 == 0) giveup("unknown bit rate %d", n); 
    return 1 << (n/2400 - 1); 
  } 
 
static uint legalbps(vmode m) 
  { switch (m) 
      { default: 
	    return 0; 
 
	case V32o: 
	    return bps_4800 | bps_7200 | bps_9600 | bps_12000 | bps_14400; 
 
	case V34o: 
	    return bps_2400 | bps_4800 | bps_7200 | bps_9600 | bps_12000 | bps_14400 | 
		   bps_16800 | bps_19200 | bps_21600 | bps_24000 | bps_26400 | bps_28800; 
      } 
  } 
 
static void checkoptions() 
  { unless (options & (opt_org | opt_ans)) usage(6);		/* need either org/ans	 */ 
    unless (~options & (opt_org | opt_ans)) usage(7);		/* but not both		 */ 
    unless (~options & (opt_fax | opt_mod)) usage(8);		/* mustn't have both fax and mod */ 
  } 
 
static void usage(int n) 
  { fprintf(stderr, "Modem Vsn. 5.1 from \n"); 
    fprintf(stderr, "Usage(%d): modem [-v] [-V8] {- | -fax} [-bps  ...] [+ | -ans]\n", n); 
    fprintf(stderr, "Modes:"); 
    for (int i = 0; vmodes[i].s != NULL; i++) fprintf(stderr, " %s", vmodes[i].s); 
    putc('\n', stderr); 
    exit(2); 
  } 
 
static void seizeline() 
  { sleep(2); /* wait in case line has only just been dropped */ 
    int fd = open(TOFN, O_RDWR); /* this asserts DTR */ 
    if (fd < 0) giveup("Can't open %s", TOFN); 
  } 
 
static void sendanswer()			/* send V.25 answer sequence   */ 
  { sendpause(2.15);				/* silence for 2.15 sec	       */ 
    sinegen *sgen = new sinegen(2100.0); 
    for (int i = 0; i < 7; i++) 
      { int ns = (int) (0.45 * SAMPLERATE);	/* 2100 Hz for 450 ms	       */ 
	for (int j = 0; j < ns; j++) 
	  { float val = sgen -> fnext(); 
	    outsample(val); 
	  } 
	sgen -> flipphase();			/* flip phase for next segment */ 
      } 
    delete sgen; 
    sendpause(0.075);				/* silence for 75 ms	       */ 
  }