2 * utils.c - various utility functions used in pppd.
4 * Copyright (c) 1999-2002 Paul Mackerras. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. The name(s) of the authors of this software must not be used to
14 * endorse or promote products derived from this software without
15 * prior written permission.
17 * 3. Redistributions of any form whatsoever must retain the following
19 * "This product includes software developed by Paul Mackerras
20 * <paulus@samba.org>".
22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
49 #include <sys/param.h>
50 #include <sys/types.h>
53 #include <sys/resource.h>
55 #include <sys/socket.h>
56 #include <netinet/in.h>
58 #include <sys/mkdev.h>
67 extern char *strerror();
70 static void logit(int, char *, va_list);
71 static void log_write(int, char *);
72 static void vslp_printer(void *, char *, ...);
73 static void format_packet(u_char *, int, printer_func, void *);
81 * strlcpy - like strcpy/strncpy, doesn't overflow destination buffer,
82 * always leaves destination null-terminated (for len > 0).
85 strlcpy(char *dest, const char *src, size_t len)
87 size_t ret = strlen(src);
93 strncpy(dest, src, len - 1);
101 * strlcat - like strcat/strncat, doesn't overflow destination buffer,
102 * always leaves destination null-terminated (for len > 0).
105 strlcat(char *dest, const char *src, size_t len)
107 size_t dlen = strlen(dest);
109 return dlen + strlcpy(dest + dlen, src, (len > dlen? len - dlen: 0));
114 * slprintf - format a message into a buffer. Like sprintf except we
115 * also specify the length of the output buffer, and we handle
116 * %m (error message), %v (visible string),
117 * %q (quoted string), %t (current time) and %I (IP address) formats.
118 * Doesn't do floating-point formats.
119 * Returns the number of chars put into buf.
122 slprintf(char *buf, int buflen, char *fmt, ...)
128 n = vslprintf(buf, buflen, fmt, args);
134 * vslprintf - like slprintf, takes a va_list instead of a list of args.
136 #define OUTCHAR(c) (buflen > 0? (--buflen, *buf++ = (c)): 0)
139 vslprintf(char *buf, int buflen, char *fmt, va_list args)
142 int width, prec, fillch;
143 int base, len, neg, quoted;
145 unsigned long val = 0;
146 char *str, *f, *buf0;
151 static char hexchars[] = "0123456789abcdef";
152 struct buffer_info bufinfo;
158 for (f = fmt; *f != '%' && *f != 0; ++f)
164 memcpy(buf, fmt, len);
180 width = va_arg(args, int);
184 width = width * 10 + c - '0';
191 prec = va_arg(args, int);
196 prec = prec * 10 + c - '0';
210 lval = va_arg(args, long);
219 val = va_arg(args, unsigned long);
225 --fmt; /* so %lz outputs %lz etc. */
230 i = va_arg(args, int);
239 val = va_arg(args, unsigned int);
243 val = va_arg(args, unsigned int);
248 val = va_arg(args, unsigned int);
252 val = (unsigned long) va_arg(args, void *);
257 str = va_arg(args, char *);
260 num[0] = va_arg(args, int);
265 str = strerror(errno);
268 ip = va_arg(args, u_int32_t);
270 slprintf(num, sizeof(num), "%d.%d.%d.%d", (ip >> 24) & 0xff,
271 (ip >> 16) & 0xff, (ip >> 8) & 0xff, ip & 0xff);
277 str += 4; /* chop off the day name */
278 str[15] = 0; /* chop off year and newline */
280 case 'v': /* "visible" string */
281 case 'q': /* quoted string */
283 p = va_arg(args, unsigned char *);
285 p = (unsigned char *)"<NULL>";
286 if (fillch == '0' && prec >= 0) {
288 termch = -1; /* matches no unsigned char value */
291 if (prec != -1 && n > prec)
293 termch = 0; /* stop on null byte */
295 while (n > 0 && buflen > 0) {
300 if (!quoted && c >= 0x80) {
305 if (quoted && (c == '"' || c == '\\'))
307 if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
311 case '\t': OUTCHAR('t'); break;
312 case '\n': OUTCHAR('n'); break;
313 case '\b': OUTCHAR('b'); break;
314 case '\f': OUTCHAR('f'); break;
317 OUTCHAR(hexchars[c >> 4]);
318 OUTCHAR(hexchars[c & 0xf]);
332 case 'P': /* print PPP packet */
334 bufinfo.len = buflen + 1;
335 p = va_arg(args, unsigned char *);
336 n = va_arg(args, int);
337 format_packet(p, n, vslp_printer, &bufinfo);
339 buflen = bufinfo.len - 1;
342 p = va_arg(args, unsigned char *);
343 for (n = prec; n > 0; --n) {
347 OUTCHAR(hexchars[(c >> 4) & 0xf]);
348 OUTCHAR(hexchars[c & 0xf]);
354 --fmt; /* so %z outputs %z etc. */
359 str = num + sizeof(num);
361 while (str > num + neg) {
362 *--str = hexchars[val % base];
364 if (--prec <= 0 && val == 0)
376 len = num + sizeof(num) - 1 - str;
378 for (len = 0; len < buflen && (prec == -1 || len < prec); ++len)
385 if ((n = width - len) > 0) {
393 memcpy(buf, str, len);
402 * vslp_printer - used in processing a %P format
405 vslp_printer(void *arg, char *fmt, ...)
409 struct buffer_info *bi;
413 bi = (struct buffer_info *) arg;
414 n = vslprintf(bi->ptr, bi->len, fmt, pvar);
423 * log_packet - format a packet and log it.
427 log_packet(u_char *p, int len, char *prefix, int level)
429 init_pr_log(prefix, level);
430 format_packet(p, len, pr_log, &level);
436 * format_packet - make a readable representation of a packet,
437 * calling `printer(arg, format, ...)' to output it.
440 format_packet(u_char *p, int len, printer_func printer, void *arg)
444 struct protent *protp;
446 if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
450 for (i = 0; (protp = protocols[i]) != NULL; ++i)
451 if (proto == protp->protocol)
454 printer(arg, "[%s", protp->name);
455 n = (*protp->printpkt)(p, len, printer, arg);
460 for (i = 0; (protp = protocols[i]) != NULL; ++i)
461 if (proto == (protp->protocol & ~0x8000))
463 if (protp != 0 && protp->data_name != 0) {
464 printer(arg, "[%s data]", protp->data_name);
466 printer(arg, "%.8B ...", p);
468 printer(arg, "%.*B", len, p);
471 printer(arg, "[proto=0x%x]", proto);
476 printer(arg, "%.32B ...", p);
478 printer(arg, "%.*B", len, p);
482 * init_pr_log, end_pr_log - initialize and finish use of pr_log.
485 static char line[256]; /* line to be logged accumulated here */
486 static char *linep; /* current pointer within line */
487 static int llevel; /* level for logging */
490 init_pr_log(const char *prefix, int level)
493 if (prefix != NULL) {
494 strlcpy(line, prefix, sizeof(line));
495 linep = line + strlen(line);
505 log_write(llevel, line);
510 * pr_log - printer routine for outputting to syslog
513 pr_log(void *arg, char *fmt, ...)
522 n = vslprintf(buf, sizeof(buf), fmt, pvar);
526 eol = strchr(buf, '\n');
528 l = (eol == NULL)? n: eol - buf;
529 if (linep + l < line + sizeof(line)) {
531 memcpy(linep, buf, l);
537 eol = strchr(p, '\n');
540 log_write(llevel, line);
544 while (eol != NULL) {
546 log_write(llevel, p);
548 eol = strchr(p, '\n');
551 /* assumes sizeof(buf) <= sizeof(line) */
560 * print_string - print a readable representation of a string using
564 print_string(char *p, int len, printer_func printer, void *arg)
569 for (; len > 0; --len) {
571 if (' ' <= c && c <= '~') {
572 if (c == '\\' || c == '"')
574 printer(arg, "%c", c);
587 printer(arg, "\\%.3o", (unsigned char) c);
595 * logit - does the hard work for fatal et al.
598 logit(int level, char *fmt, va_list args)
602 vslprintf(buf, sizeof(buf), fmt, args);
603 log_write(level, buf);
607 log_write(int level, char *buf)
609 syslog(level, "%s", buf);
610 if (log_to_fd >= 0 && (level != LOG_DEBUG || debug)) {
613 if (n > 0 && buf[n-1] == '\n')
615 if (write(log_to_fd, buf, n) != n
616 || write(log_to_fd, "\n", 1) != 1)
622 * fatal - log an error message and die horribly.
625 fatal(char *fmt, ...)
631 logit(LOG_ERR, fmt, pvar);
634 die(1); /* as promised */
638 * error - log an error message.
641 error(char *fmt, ...)
647 logit(LOG_ERR, fmt, pvar);
653 * warn - log a warning message.
662 logit(LOG_WARNING, fmt, pvar);
667 * notice - log a notice-level message.
670 notice(char *fmt, ...)
676 logit(LOG_NOTICE, fmt, pvar);
681 * info - log an informational message.
690 logit(LOG_INFO, fmt, pvar);
695 * dbglog - log a debug message.
698 dbglog(char *fmt, ...)
704 logit(LOG_DEBUG, fmt, pvar);
709 * dump_packet - print out a packet in readable form if it is interesting.
710 * Assumes len >= PPP_HDRLEN.
713 dump_packet(const char *tag, unsigned char *p, int len)
721 * don't print LCP echo request/reply packets if debug <= 1
722 * and the link is up.
724 proto = (p[2] << 8) + p[3];
725 if (debug <= 1 && unsuccess == 0 && proto == PPP_LCP
726 && len >= PPP_HDRLEN + HEADERLEN) {
727 unsigned char *lcp = p + PPP_HDRLEN;
728 int l = (lcp[2] << 8) + lcp[3];
730 if ((lcp[0] == ECHOREQ || lcp[0] == ECHOREP)
731 && l >= HEADERLEN && l <= len - PPP_HDRLEN)
735 dbglog("%s %P", tag, p, len);
739 * complete_read - read a full `count' bytes from fd,
740 * unless end-of-file or an error other than EINTR is encountered.
743 complete_read(int fd, void *buf, size_t count)
749 for (done = 0; done < count; ) {
750 nb = read(fd, ptr, count - done);
752 if (errno == EINTR && !got_sigterm)
764 /* Procedures for locking the serial device using a lock file. */
767 #define LOCK_DIR "/var/lock"
770 #define LOCK_DIR "/var/spool/locks"
772 #define LOCK_DIR "/var/spool/lock"
775 #endif /* LOCK_DIR */
777 static char lock_file[MAXPATHLEN];
780 * lock - create a lock file for the named device
788 result = mklock (dev, (void *) 0);
790 strlcpy(lock_file, dev, sizeof(lock_file));
795 notice("Device %s is locked by pid %d", dev, result);
797 error("Can't create lock file %s", lock_file);
802 char lock_buffer[12];
808 if (stat(dev, &sbuf) < 0) {
809 error("Can't get device number for %s: %m", dev);
812 if ((sbuf.st_mode & S_IFMT) != S_IFCHR) {
813 error("Can't lock %s: not a character device", dev);
816 slprintf(lock_file, sizeof(lock_file), "%s/LK.%03d.%03d.%03d",
817 LOCK_DIR, major(sbuf.st_dev),
818 major(sbuf.st_rdev), minor(sbuf.st_rdev));
821 char lockdev[MAXPATHLEN];
823 if ((p = strstr(dev, "dev/")) != NULL) {
825 strncpy(lockdev, dev, MAXPATHLEN-1);
826 lockdev[MAXPATHLEN-1] = 0;
827 while ((p = strrchr(lockdev, '/')) != NULL) {
832 if ((p = strrchr(dev, '/')) != NULL)
835 slprintf(lock_file, sizeof(lock_file), "%s/LCK..%s", LOCK_DIR, dev);
838 while ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) < 0) {
839 if (errno != EEXIST) {
840 error("Can't create lock file %s: %m", lock_file);
844 /* Read the lock file to find out who has the device locked. */
845 fd = open(lock_file, O_RDONLY, 0);
847 if (errno == ENOENT) /* This is just a timing problem. */
849 error("Can't open existing lock file %s: %m", lock_file);
853 n = read(fd, lock_buffer, 11);
855 n = read(fd, &pid, sizeof(pid));
856 #endif /* LOCK_BINARY */
860 error("Can't read pid from lock file %s", lock_file);
864 /* See if the process still exists. */
867 pid = atoi(lock_buffer);
868 #endif /* LOCK_BINARY */
870 return 1; /* somebody else locked it for us */
872 || (kill(pid, 0) == -1 && errno == ESRCH)) {
873 if (unlink (lock_file) == 0) {
874 notice("Removed stale lock on %s (pid %d)", dev, pid);
877 warn("Couldn't remove stale lock on %s", dev);
879 notice("Device %s is locked by pid %d", dev, pid);
890 slprintf(lock_buffer, sizeof(lock_buffer), "%10d\n", pid);
891 write (fd, lock_buffer, 11);
893 write(fd, &pid, sizeof (pid));
902 * relock - called to update our lockfile when we are about to detach,
903 * thus changing our pid (we fork, the child carries on, and the parent dies).
904 * Note that this is called by the parent, with pid equal to the pid
905 * of the child. This avoids a potential race which would exist if
906 * we had the child rewrite the lockfile (the parent might die first,
907 * and another process could think the lock was stale if it checked
908 * between when the parent died and the child rewrote the lockfile).
914 /* XXX is there a way to do this? */
919 char lock_buffer[12];
921 if (lock_file[0] == 0)
923 fd = open(lock_file, O_WRONLY, 0);
925 error("Couldn't reopen lock file %s: %m", lock_file);
931 slprintf(lock_buffer, sizeof(lock_buffer), "%10d\n", pid);
932 write (fd, lock_buffer, 11);
934 write(fd, &pid, sizeof(pid));
935 #endif /* LOCK_BINARY */
943 * unlock - remove our lockfile
950 (void) rmlock(lock_file, (void *) 0);