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