usr/src/cmd/cmd-inet/usr.bin/pppd/utils.c

   1 /*
   2  * utils.c - various utility functions used in pppd.
   3  *
   4  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   5  * Use is subject to license terms.
   6  *
   7  * Permission to use, copy, modify, and distribute this software and its
   8  * documentation is hereby granted, provided that the above copyright
   9  * notice appears in all copies.
  10  *
  11  * SUN MAKES NO REPRESENTATION OR WARRANTIES ABOUT THE SUITABILITY OF
  12  * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
  13  * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  14  * PARTICULAR PURPOSE, OR NON-INFRINGEMENT.  SUN SHALL NOT BE LIABLE FOR
  15  * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
  16  * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES
  17  *
  18  * Copyright (c) 1999 The Australian National University.
  19  * All rights reserved.
  20  *
  21  * Redistribution and use in source and binary forms are permitted
  22  * provided that the above copyright notice and this paragraph are
  23  * duplicated in all such forms and that any documentation,
  24  * advertising materials, and other materials related to such
  25  * distribution and use acknowledge that the software was developed
  26  * by the Australian National University.  The name of the University
  27  * may not be used to endorse or promote products derived from this
  28  * software without specific prior written permission.
  29  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  30  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  31  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  32  */
  33
  34 #pragma ident   "%Z%%M% %I%     %E% SMI"
  35 #define RCSID   "$Id: utils.c,v 1.10 2000/03/27 01:36:48 paulus Exp $"
  36
  37 #ifdef __linux__
  38 #define _GNU_SOURCE
  39 #endif
  40 #include <stdio.h>
  41 #include <ctype.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45 #include <signal.h>
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <syslog.h>
  49 #include <netdb.h>
  50 #include <utmp.h>
  51 #include <pwd.h>
  52 #include <sys/param.h>
  53 #include <sys/types.h>
  54 #include <sys/wait.h>
  55 #include <sys/time.h>
  56 #include <sys/resource.h>
  57 #include <sys/stat.h>
  58 #include <sys/socket.h>
  59 #include <netinet/in.h>
  60 #ifdef SVR4
  61 #include <sys/mkdev.h>
  62 #endif
  63
  64 #include "pppd.h"
  65
  66 #if !defined(lint) && !defined(_lint)
  67 static const char rcsid[] = RCSID;
  68 #endif
  69
  70 #if defined(SUNOS4)
  71 extern char *strerror();
  72 #endif
  73
  74 /* Don't log to stdout until we're sure it's ok to do so. */
  75 bool early_log = 1;
  76
  77 static void pr_log __P((void *, const char *, ...));
  78 static void logit __P((int, const char *, va_list));
  79 static void vslp_printer __P((void *, const char *, ...));
  80 static void format_packet __P((u_char *, int,
  81     void (*) (void *, const char *, ...), void *));
  82
  83 struct buffer_info {
  84     char *ptr;
  85     int len;
  86 };
  87
  88 /*
  89  * strllen - like strlen, but doesn't run past end of input.
  90  */
  91 size_t
  92 strllen(str, len)
  93     const char *str;
  94     size_t len;
  95 {
  96     size_t ret;
  97
  98     for (ret = 0; ret < len; ret++)
  99         if (*str++ == '\0')
 100             break;
 101     return (ret);
 102 }
 103
 104 /*
 105  * slprintf - format a message into a buffer.  Like sprintf except we
 106  * also specify the length of the output buffer, and we handle %m
 107  * (error message), %v (visible string), %q (quoted string), %t
 108  * (current time), %I (IP address), %P (PPP packet), and %B (sequence
 109  * of bytes) formats.  Doesn't do floating-point formats.  Returns the
 110  * number of chars put into buf.
 111  */
 112 int
 113 slprintf __V((char *buf, int buflen, const char *fmt, ...))
 114 {
 115     va_list args;
 116     int n;
 117
 118 #if defined(__STDC__)
 119     va_start(args, fmt);
 120 #else
 121     char *buf;
 122     int buflen;
 123     const char *fmt;
 124     va_start(args);
 125     buf = va_arg(args, char *);
 126     buflen = va_arg(args, int);
 127     fmt = va_arg(args, const char *);
 128 #endif
 129     n = vslprintf(buf, buflen, fmt, args);
 130     va_end(args);
 131     return (n);
 132 }
 133
 134 /*
 135  * Print to file or, if argument is NULL, to syslog at debug level.
 136  */
 137 int
 138 flprintf __V((FILE *strptr, const char *fmt, ...))
 139 {
 140     va_list args;
 141     int n;
 142     char buf[1024], *bp, *nlp, *ebp;
 143
 144 #if defined(__STDC__)
 145     va_start(args, fmt);
 146 #else
 147     FILE *strptr;
 148     const char *fmt;
 149     va_start(args);
 150     strptr = va_arg(args, FILE *);
 151     fmt = va_arg(args, const char *);
 152 #endif
 153     n = vslprintf(buf, sizeof (buf), fmt, args);
 154     va_end(args);
 155     if (strptr == NULL) {
 156         bp = buf;
 157         ebp = buf + n;
 158         while (bp < ebp) {
 159             if ((nlp = strchr(bp, '\n')) == NULL)
 160                 nlp = ebp;
 161             if (nlp > bp) {
 162                 *nlp = '\0';
 163                 syslog(LOG_DEBUG, "%s", bp);
 164             }
 165             bp = nlp + 1;
 166         }
 167     } else {
 168         n = fwrite(buf, 1, n, strptr);
 169     }
 170     return (n);
 171 }
 172
 173 /*
 174  * vslprintf - like slprintf, takes a va_list instead of a list of args.
 175  */
 176 #define OUTCHAR(c)      (buflen > 0? (--buflen, *buf++ = (c)): 0)
 177
 178 int
 179 vslprintf(buf, buflen, fmt, args)
 180     char *buf;
 181     int buflen;
 182     const char *fmt;
 183     va_list args;
 184 {
 185     int c, n, longs;
 186     int width, prec, fillch;
 187     int base, len, neg, quoted;
 188 #ifdef SOL2
 189     uint64_t val;
 190     int64_t sval;
 191 #else
 192     unsigned long val;
 193     long sval;
 194 #endif
 195     char *buf0, *mstr;
 196     const char *f, *str;
 197     unsigned char *p;
 198     char num[32];       /* 2^64 is 20 chars decimal, 22 octal */
 199     time_t t;
 200     u_int32_t ip;
 201     static const char hexchars[] = "0123456789abcdef";
 202     struct buffer_info bufinfo;
 203
 204     buf0 = buf;
 205     --buflen;
 206     while (buflen > 0) {
 207         for (f = fmt; *f != '%' && *f != 0; ++f)
 208             ;
 209         if (f > fmt) {
 210             len = f - fmt;
 211             if (len > buflen)
 212                 len = buflen;
 213             (void) memcpy(buf, fmt, len);
 214             buf += len;
 215             buflen -= len;
 216             fmt = f;
 217         }
 218         if (*fmt == 0)
 219             break;
 220         c = *++fmt;
 221         width = 0;
 222         prec = -1;
 223         fillch = ' ';
 224         if (c == '0') {
 225             fillch = '0';
 226             c = *++fmt;
 227         }
 228         if (c == '*') {
 229             width = va_arg(args, int);
 230             c = *++fmt;
 231         } else {
 232             while (isdigit(c)) {
 233                 width = width * 10 + c - '0';
 234                 c = *++fmt;
 235             }
 236         }
 237         if (c == '.') {
 238             c = *++fmt;
 239             if (c == '*') {
 240                 prec = va_arg(args, int);
 241                 c = *++fmt;
 242             } else {
 243                 prec = 0;
 244                 while (isdigit(c)) {
 245                     prec = prec * 10 + c - '0';
 246                     c = *++fmt;
 247                 }
 248             }
 249         }
 250         longs = 0;
 251         if (c == 'l') {
 252             longs++;
 253             c = *++fmt;
 254             if (c == 'l') {
 255                 longs++;
 256                 c = *++fmt;
 257             }
 258         }
 259         str = 0;
 260         base = 0;
 261         neg = 0;
 262         val = 0;
 263         ++fmt;
 264         switch (c) {
 265         case 'u':
 266 #ifdef SOL2
 267             if (longs >= 2)
 268                 val = va_arg(args, uint64_t);
 269             else
 270 #endif
 271             if (longs > 0)
 272                 val = va_arg(args, unsigned long);
 273             else
 274                 val = va_arg(args, unsigned int);
 275             base = 10;
 276             break;
 277         case 'd':
 278 #ifdef SOL2
 279             if (longs >= 2)
 280                 sval = va_arg(args, int64_t);
 281             else
 282 #endif
 283             if (longs > 0)
 284                 sval = va_arg(args, long);
 285             else
 286                 sval = va_arg(args, int);
 287             if (sval < 0) {
 288                 neg = 1;
 289                 val = -sval;
 290             } else
 291                 val = sval;
 292             base = 10;
 293             break;
 294         case 'o':
 295 #ifdef SOL2
 296             if (longs >= 2)
 297                 val = va_arg(args, uint64_t);
 298             else
 299 #endif
 300             if (longs > 0)
 301                 val = va_arg(args, unsigned long);
 302             else
 303                 val = va_arg(args, unsigned int);
 304             base = 8;
 305             break;
 306         case 'x':
 307         case 'X':
 308 #ifdef SOL2
 309             if (longs >= 2)
 310                 val = va_arg(args, uint64_t);
 311             else
 312 #endif
 313             if (longs > 0)
 314                 val = va_arg(args, unsigned long);
 315             else
 316                 val = va_arg(args, unsigned int);
 317             base = 16;
 318             break;
 319         case 'p':
 320             val = (unsigned long) va_arg(args, void *);
 321             base = 16;
 322             neg = 2;
 323             break;
 324         case 's':
 325             str = va_arg(args, const char *);
 326             break;
 327         case 'c':
 328             num[0] = va_arg(args, int);
 329             num[1] = 0;
 330             str = num;
 331             break;
 332         case 'm':
 333             str = strerror(errno);
 334             break;
 335         case 'I':
 336             ip = va_arg(args, u_int32_t);
 337             ip = ntohl(ip);
 338             (void) slprintf(num, sizeof(num), "%d.%d.%d.%d", (ip >> 24) & 0xff,
 339                 (ip >> 16) & 0xff, (ip >> 8) & 0xff, ip & 0xff);
 340             str = num;
 341             break;
 342         case 't':
 343             (void) time(&t);
 344             mstr = ctime(&t);
 345             mstr += 4;          /* chop off the day name */
 346             mstr[15] = 0;       /* chop off year and newline */
 347             str = (const char *)mstr;
 348             break;
 349         case 'v':               /* "visible" string */
 350         case 'q':               /* quoted string */
 351             quoted = c == 'q';
 352             p = va_arg(args, unsigned char *);
 353             if (fillch == '0' && prec >= 0) {
 354                 n = prec;
 355             } else {
 356                 n = strlen((char *)p);
 357                 if (prec >= 0 && n > prec)
 358                     n = prec;
 359             }
 360             while (n > 0 && buflen > 0) {
 361                 c = *p++;
 362                 --n;
 363                 if (!quoted && c >= 0x80) {
 364                     (void) OUTCHAR('M');
 365                     (void) OUTCHAR('-');
 366                     c -= 0x80;
 367                 }
 368                 if (quoted && (c == '"' || c == '\\'))
 369                     (void) OUTCHAR('\\');
 370                 if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
 371                     if (quoted) {
 372                         (void) OUTCHAR('\\');
 373                         switch (c) {
 374                         case '\t':      (void) OUTCHAR('t');    break;
 375                         case '\n':      (void) OUTCHAR('n');    break;
 376                         case '\b':      (void) OUTCHAR('b');    break;
 377                         case '\f':      (void) OUTCHAR('f');    break;
 378                         default:
 379                             (void) OUTCHAR('x');
 380                             (void) OUTCHAR(hexchars[c >> 4]);
 381                             (void) OUTCHAR(hexchars[c & 0xf]);
 382                         }
 383                     } else {
 384                         if (c == '\t')
 385                             (void) OUTCHAR(c);
 386                         else {
 387                             (void) OUTCHAR('^');
 388                             (void) OUTCHAR(c ^ 0x40);
 389                         }
 390                     }
 391                 } else
 392                     (void) OUTCHAR(c);
 393             }
 394             continue;
 395         case 'P':               /* print PPP packet */
 396             bufinfo.ptr = buf;
 397             bufinfo.len = buflen + 1;
 398             p = va_arg(args, unsigned char *);
 399             n = va_arg(args, int);
 400             format_packet(p, n, vslp_printer, &bufinfo);
 401             buf = bufinfo.ptr;
 402             buflen = bufinfo.len - 1;
 403             continue;
 404         case 'B':
 405             p = va_arg(args, unsigned char *);
 406             if ((n = prec) > width && width > 0)
 407                 n = width;
 408             /* For safety's sake */
 409             if (n > 2000)
 410                     n = 2000;
 411             while (--n >= 0) {
 412                 c = *p++;
 413                 if (fillch == ' ')
 414                     (void) OUTCHAR(' ');
 415                 (void) OUTCHAR(hexchars[(c >> 4) & 0xf]);
 416                 (void) OUTCHAR(hexchars[c & 0xf]);
 417             }
 418             if (prec > width && width > 0) {
 419                 (void) OUTCHAR('.');
 420                 (void) OUTCHAR('.');
 421                 (void) OUTCHAR('.');
 422             }
 423             continue;
 424         default:
 425             *buf++ = '%';
 426             if (c != '%')
 427                 --fmt;          /* so %z outputs %z etc. */
 428             --buflen;
 429             continue;
 430         }
 431         if (base != 0) {
 432             mstr = num + sizeof(num);
 433             *--mstr = 0;
 434             while (mstr > num + neg) {
 435                 *--mstr = hexchars[val % base];
 436                 val = val / base;
 437                 if (--prec <= 0 && val == 0)
 438                     break;
 439             }
 440             switch (neg) {
 441             case 1:
 442                 *--mstr = '-';
 443                 break;
 444             case 2:
 445                 *--mstr = 'x';
 446                 *--mstr = '0';
 447                 break;
 448             }
 449             len = num + sizeof(num) - 1 - mstr;
 450             str = (const char *)mstr;
 451         } else {
 452             len = strlen(str);
 453             if (prec >= 0 && len > prec)
 454                 len = prec;
 455         }
 456         if (width > 0) {
 457             if (width > buflen)
 458                 width = buflen;
 459             if ((n = width - len) > 0) {
 460                 buflen -= n;
 461                 for (; n > 0; --n)
 462                     *buf++ = fillch;
 463             }
 464         }
 465         if (len > buflen)
 466             len = buflen;
 467         (void) memcpy(buf, str, len);
 468         buf += len;
 469         buflen -= len;
 470     }
 471     *buf = 0;
 472     return (buf - buf0);
 473 }
 474
 475 /*
 476  * vslp_printer - used in processing a %P format
 477  */
 478 static void
 479 vslp_printer __V((void *arg, const char *fmt, ...))
 480 {
 481     int n;
 482     va_list pvar;
 483     struct buffer_info *bi;
 484
 485 #if defined(__STDC__)
 486     va_start(pvar, fmt);
 487 #else
 488     void *arg;
 489     const char *fmt;
 490     va_start(pvar);
 491     arg = va_arg(pvar, void *);
 492     fmt = va_arg(pvar, const char *);
 493 #endif
 494
 495     bi = (struct buffer_info *) arg;
 496     n = vslprintf(bi->ptr, bi->len, fmt, pvar);
 497     va_end(pvar);
 498
 499     bi->ptr += n;
 500     bi->len -= n;
 501 }
 502
 503 /*
 504  * log_packet - format a packet and log it.
 505  */
 506
 507 static char line[256];          /* line to be logged accumulated here */
 508 static char *linep;
 509
 510 void
 511 log_packet(p, len, prefix, level)
 512     u_char *p;
 513     int len;
 514     const char *prefix;
 515     int level;
 516 {
 517     (void) strlcpy(line, prefix, sizeof(line));
 518     linep = line + strlen(line);
 519     format_packet(p, len, pr_log, (void *)level);
 520     if (linep != line)
 521         syslog(level, "%s", line);
 522 }
 523
 524 /*
 525  * format_packet - make a readable representation of a packet,
 526  * calling `printer(arg, format, ...)' to output it.
 527  */
 528 static void
 529 format_packet(p, len, printer, arg)
 530     u_char *p;
 531     int len;
 532     void (*printer) __P((void *, const char *, ...));
 533     void *arg;
 534 {
 535     int i, n;
 536     u_short proto;
 537     struct protent *protp;
 538
 539     if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
 540         p += 2;
 541         GETSHORT(proto, p);
 542         len -= PPP_HDRLEN;
 543         for (i = 0; (protp = protocols[i]) != NULL; ++i)
 544             if (proto == protp->protocol)
 545                 break;
 546         if (protp != NULL) {
 547             printer(arg, "[%s", protp->name);
 548             n = (*protp->printpkt)(p, len, printer, arg);
 549             printer(arg, "]");
 550             p += n;
 551             len -= n;
 552         } else {
 553             for (i = 0; (protp = protocols[i]) != NULL; ++i)
 554                 if (proto == (protp->protocol & ~0x8000))
 555                     break;
 556             if (protp != NULL && protp->data_name != NULL) {
 557                 printer(arg, "[%s data] %8.*B", protp->data_name, len, p);
 558                 len = 0;
 559             } else
 560                 printer(arg, "[proto=0x%x]", proto);
 561         }
 562     }
 563
 564     printer(arg, "%32.*B", len, p);
 565 }
 566
 567 static void
 568 pr_log __V((void *arg, const char *fmt, ...))
 569 {
 570     int n;
 571     va_list pvar;
 572     char buf[256];
 573
 574 #if defined(__STDC__)
 575     va_start(pvar, fmt);
 576 #else
 577     void *arg;
 578     const char *fmt;
 579     va_start(pvar);
 580     arg = va_arg(pvar, void *);
 581     fmt = va_arg(pvar, const char *);
 582 #endif
 583
 584     n = vslprintf(buf, sizeof(buf), fmt, pvar);
 585     va_end(pvar);
 586
 587     if (linep + n + 1 > line + sizeof(line)) {
 588         syslog((int)arg, "%s", line);
 589         linep = line;
 590     }
 591     (void) strlcpy(linep, buf, line + sizeof(line) - linep);
 592     linep += n;
 593 }
 594
 595 /*
 596  * print_string - print a readable representation of a string using
 597  * printer.
 598  */
 599 void
 600 print_string(p, len, printer, arg)
 601     char *p;
 602     int len;
 603     void (*printer) __P((void *, const char *, ...));
 604     void *arg;
 605 {
 606     int c;
 607
 608     printer(arg, "\"");
 609     for (; len > 0; --len) {
 610         c = *p++;
 611         if (isprint(c)) {
 612             if (c == '\\' || c == '"')
 613                 printer(arg, "\\");
 614             printer(arg, "%c", c);
 615         } else {
 616             switch (c) {
 617             case '\n':
 618                 printer(arg, "\\n");
 619                 break;
 620             case '\r':
 621                 printer(arg, "\\r");
 622                 break;
 623             case '\t':
 624                 printer(arg, "\\t");
 625                 break;
 626             default:
 627                 printer(arg, "\\%.3o", c);
 628             }
 629         }
 630     }
 631     printer(arg, "\"");
 632 }
 633
 634 /*
 635  * logit - does the hard work for fatal et al.
 636  */
 637 static void
 638 logit(level, fmt, args)
 639     int level;
 640     const char *fmt;
 641     va_list args;
 642 {
 643     int n;
 644     char buf[1024];
 645
 646     n = vslprintf(buf, sizeof(buf), fmt, args);
 647     syslog(level, "%s", buf);
 648     if (log_to_fd >= 0 && (level != LOG_DEBUG || debug) &&
 649         (!early_log || log_to_specific_fd)) {
 650         if (buf[n-1] != '\n')
 651             buf[n++] = '\n';
 652         if (write(log_to_fd, buf, n) != n)
 653             log_to_fd = -1;
 654     }
 655 }
 656
 657 /*
 658  * fatal - log an error message and die horribly.
 659  */
 660 void
 661 fatal __V((const char *fmt, ...))
 662 {
 663     va_list pvar;
 664
 665 #if defined(__STDC__)
 666     va_start(pvar, fmt);
 667 #else
 668     const char *fmt;
 669     va_start(pvar);
 670     fmt = va_arg(pvar, const char *);
 671 #endif
 672
 673     logit(LOG_ERR, fmt, pvar);
 674     va_end(pvar);
 675
 676     die(1);                     /* as promised */
 677 }
 678
 679 /*
 680  * error - log an error message.
 681  */
 682 void
 683 error __V((const char *fmt, ...))
 684 {
 685     va_list pvar;
 686
 687 #if defined(__STDC__)
 688     va_start(pvar, fmt);
 689 #else
 690     const char *fmt;
 691     va_start(pvar);
 692     fmt = va_arg(pvar, const char *);
 693 #endif
 694
 695     logit(LOG_ERR, fmt, pvar);
 696     va_end(pvar);
 697 }
 698
 699 /*
 700  * warn - log a warning message.
 701  */
 702 void
 703 warn __V((const char *fmt, ...))
 704 {
 705     va_list pvar;
 706
 707 #if defined(__STDC__)
 708     va_start(pvar, fmt);
 709 #else
 710     const char *fmt;
 711     va_start(pvar);
 712     fmt = va_arg(pvar, const char *);
 713 #endif
 714
 715     logit(LOG_WARNING, fmt, pvar);
 716     va_end(pvar);
 717 }
 718
 719 /*
 720  * notice - log a notice-level message.
 721  */
 722 void
 723 notice __V((const char *fmt, ...))
 724 {
 725     va_list pvar;
 726
 727 #if defined(__STDC__)
 728     va_start(pvar, fmt);
 729 #else
 730     const char *fmt;
 731     va_start(pvar);
 732     fmt = va_arg(pvar, const char *);
 733 #endif
 734
 735     logit(LOG_NOTICE, fmt, pvar);
 736     va_end(pvar);
 737 }
 738
 739 /*
 740  * info - log an informational message.
 741  */
 742 void
 743 info __V((const char *fmt, ...))
 744 {
 745     va_list pvar;
 746
 747 #if defined(__STDC__)
 748     va_start(pvar, fmt);
 749 #else
 750     const char *fmt;
 751     va_start(pvar);
 752     fmt = va_arg(pvar, const char *);
 753 #endif
 754
 755     logit(LOG_INFO, fmt, pvar);
 756     va_end(pvar);
 757 }
 758
 759 /*
 760  * dbglog - log a debug message.
 761  */
 762 void
 763 dbglog __V((const char *fmt, ...))
 764 {
 765     va_list pvar;
 766
 767 #if defined(__STDC__)
 768     va_start(pvar, fmt);
 769 #else
 770     const char *fmt;
 771     va_start(pvar);
 772     fmt = va_arg(pvar, const char *);
 773 #endif
 774
 775     logit(LOG_DEBUG, fmt, pvar);
 776     va_end(pvar);
 777 }
 778
 779 /*
 780  * Code names for regular PPP messages.  Used by LCP and most NCPs,
 781  * not used by authentication protocols.
 782  */
 783 const char *
 784 code_name(int code, int shortflag)
 785 {
 786     static const char *codelist[] = {
 787         "Vendor-Extension", "Configure-Request", "Configure-Ack",
 788         "Configure-Nak", "Configure-Reject", "Terminate-Request",
 789         "Terminate-Ack", "Code-Reject", "Protocol-Reject",
 790         "Echo-Request", "Echo-Reply", "Discard-Request",
 791         "Identification", "Time-Remaining",
 792         "Reset-Request", "Reset-Ack"
 793     };
 794     static const char *shortcode[] = {
 795         "VendExt", "ConfReq", "ConfAck",
 796         "ConfNak", "ConfRej", "TermReq",
 797         "TermAck", "CodeRej", "ProtRej",
 798         "EchoReq", "EchoRep", "DiscReq",
 799         "Ident", "TimeRem",
 800         "ResetReq", "ResetAck"
 801     };
 802     static char msgbuf[64];
 803
 804     if (code < 0 || code >= sizeof (codelist) / sizeof (*codelist)) {
 805         if (shortflag)
 806             (void) slprintf(msgbuf, sizeof (msgbuf), "Code#%d", code);
 807         else
 808             (void) slprintf(msgbuf, sizeof (msgbuf), "unknown code %d", code);
 809         return ((const char *)msgbuf);
 810     }
 811     return (shortflag ? shortcode[code] : codelist[code]);
 812 }
 813
 814 /* Procedures for locking the serial device using a lock file. */
 815 #ifndef LOCK_DIR
 816 #ifdef _linux_
 817 #define LOCK_DIR        "/var/lock"
 818 #else
 819 #ifdef SVR4
 820 #define LOCK_DIR        "/var/spool/locks"
 821 #else
 822 #define LOCK_DIR        "/var/spool/lock"
 823 #endif
 824 #endif
 825 #endif /* LOCK_DIR */
 826
 827 static char lock_file[MAXPATHLEN];
 828
 829 /*
 830  * lock - create a lock file for the named device
 831  */
 832 int
 833 lock(dev)
 834     char *dev;
 835 {
 836 #ifdef LOCKLIB
 837     int result;
 838
 839     result = mklock (dev, (void *) 0);
 840     if (result == 0) {
 841         (void) strlcpy(lock_file, sizeof(lock_file), dev);
 842         return (0);
 843     }
 844
 845     if (result > 0)
 846         notice("Device %s is locked by pid %d", dev, result);
 847     else
 848         error("Can't create lock file %s", lock_file);
 849     return (-1);
 850
 851 #else /* LOCKLIB */
 852
 853     char lock_buffer[12];
 854     int fd, pid, n;
 855
 856 #ifdef SVR4
 857     struct stat sbuf;
 858
 859     if (stat(dev, &sbuf) < 0) {
 860         error("Can't get device number for %s: %m", dev);
 861         return (-1);
 862     }
 863     if ((sbuf.st_mode & S_IFMT) != S_IFCHR) {
 864         error("Can't lock %s: not a character device", dev);
 865         return (-1);
 866     }
 867     (void) slprintf(lock_file, sizeof(lock_file), "%s/LK.%03d.%03d.%03d",
 868              LOCK_DIR, major(sbuf.st_dev),
 869              major(sbuf.st_rdev), minor(sbuf.st_rdev));
 870 #else
 871     char *p;
 872
 873     if ((p = strrchr(dev, '/')) != NULL)
 874         dev = p + 1;
 875     (void) slprintf(lock_file, sizeof(lock_file), "%s/LCK..%s", LOCK_DIR, dev);
 876 #endif
 877
 878     while ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) < 0) {
 879         if (errno != EEXIST) {
 880             error("Can't create lock file %s: %m", lock_file);
 881             break;
 882         }
 883
 884         /* Read the lock file to find out who has the device locked. */
 885         fd = open(lock_file, O_RDONLY, 0);
 886         if (fd < 0) {
 887             if (errno == ENOENT) /* This is just a timing problem. */
 888                 continue;
 889             error("Can't open existing lock file %s: %m", lock_file);
 890             break;
 891         }
 892 #ifndef LOCK_BINARY
 893         n = read(fd, lock_buffer, 11);
 894 #else
 895         n = read(fd, &pid, sizeof(pid));
 896 #endif /* LOCK_BINARY */
 897         (void) close(fd);
 898         fd = -1;
 899         if (n <= 0) {
 900             error("Can't read pid from lock file %s", lock_file);
 901             break;
 902         }
 903
 904         /* See if the process still exists. */
 905 #ifndef LOCK_BINARY
 906         lock_buffer[n] = 0;
 907         pid = atoi(lock_buffer);
 908 #endif /* LOCK_BINARY */
 909         if (pid == getpid())
 910             return (1);         /* somebody else locked it for us */
 911         if (pid == 0
 912             || (kill(pid, 0) == -1 && errno == ESRCH)) {
 913             if (unlink (lock_file) == 0) {
 914                 notice("Removed stale lock on %s (pid %d)", dev, pid);
 915                 continue;
 916             }
 917             warn("Couldn't remove stale lock on %s", dev);
 918         } else
 919             notice("Device %s is locked by pid %d", dev, pid);
 920         break;
 921     }
 922
 923     if (fd < 0) {
 924         lock_file[0] = 0;
 925         return (-1);
 926     }
 927
 928     pid = getpid();
 929 #ifndef LOCK_BINARY
 930     (void) slprintf(lock_buffer, sizeof(lock_buffer), "%10d\n", pid);
 931     (void) write (fd, lock_buffer, 11);
 932 #else
 933     (void) write(fd, &pid, sizeof (pid));
 934 #endif
 935     (void) close(fd);
 936     return (0);
 937
 938 #endif
 939 }
 940
 941 /*
 942  * relock - called to update our lockfile when we are about to detach,
 943  * thus changing our pid (we fork, the child carries on, and the parent dies).
 944  * Note that this is called by the parent, with pid equal to the pid
 945  * of the child.  This avoids a potential race which would exist if
 946  * we had the child rewrite the lockfile (the parent might die first,
 947  * and another process could think the lock was stale if it checked
 948  * between when the parent died and the child rewrote the lockfile).
 949  */
 950 int
 951 relock(pid)
 952     int pid;
 953 {
 954 #ifdef LOCKLIB
 955     /* XXX is there a way to do this? */
 956     return (-1);
 957 #else /* LOCKLIB */
 958
 959     int fd;
 960     char lock_buffer[12];
 961
 962     if (lock_file[0] == 0)
 963         return (-1);
 964     fd = open(lock_file, O_WRONLY, 0);
 965     if (fd < 0) {
 966         error("Couldn't reopen lock file %s: %m", lock_file);
 967         lock_file[0] = 0;
 968         return (-1);
 969     }
 970
 971 #ifndef LOCK_BINARY
 972     (void) slprintf(lock_buffer, sizeof(lock_buffer), "%10d\n", pid);
 973     (void) write (fd, lock_buffer, 11);
 974 #else
 975     (void) write(fd, &pid, sizeof(pid));
 976 #endif /* LOCK_BINARY */
 977     (void) close(fd);
 978     return (0);
 979
 980 #endif /* LOCKLIB */
 981 }
 982
 983 /*
 984  * unlock - remove our lockfile
 985  */
 986 void
 987 unlock()
 988 {
 989     if (lock_file[0]) {
 990 #ifdef LOCKLIB
 991         (void) rmlock(lock_file, (void *) 0);
 992 #else
 993         (void) unlink(lock_file);
 994 #endif
 995         lock_file[0] = 0;
 996     }
 997 }
 998
 999 const char *
1000 signal_name(int signum)
1001 {
1002 #if defined(SOL2) || defined(__linux__) || defined(_linux_)
1003     const char *cp;
1004
1005     if ((cp = strsignal(signum)) != NULL)
1006         return (cp);
1007 #else
1008     extern char *sys_siglist[];
1009     extern int sys_nsig;
1010
1011     if (signum >= 0 && signum < sys_nsig && sys_siglist[signum] != NULL)
1012         return (sys_siglist[signum]);
1013 #endif
1014     return ("??");
1015 }