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.
45 #include <sys/param.h>
46 #include <sys/types.h>
49 #include <sys/resource.h>
51 #include <sys/socket.h>
52 #include <netinet/in.h>
54 #include <sys/mkdev.h>
63 extern char *strerror();
66 static void logit(int, char *, va_list);
67 static void log_write(int, char *);
68 static void vslp_printer(void *, char *, ...);
69 static void format_packet(u_char *, int, printer_func, void *);
77 * strlcpy - like strcpy/strncpy, doesn't overflow destination buffer,
78 * always leaves destination null-terminated (for len > 0).
81 strlcpy(char *dest, const char *src, size_t len)
83 size_t ret = strlen(src);
89 strncpy(dest, src, len - 1);
97 * strlcat - like strcat/strncat, doesn't overflow destination buffer,
98 * always leaves destination null-terminated (for len > 0).
101 strlcat(char *dest, const char *src, size_t len)
103 size_t dlen = strlen(dest);
105 return dlen + strlcpy(dest + dlen, src, (len > dlen? len - dlen: 0));
110 * slprintf - format a message into a buffer. Like sprintf except we
111 * also specify the length of the output buffer, and we handle
112 * %m (error message), %v (visible string),
113 * %q (quoted string), %t (current time) and %I (IP address) formats.
114 * Doesn't do floating-point formats.
115 * Returns the number of chars put into buf.
118 slprintf(char *buf, int buflen, char *fmt, ...)
124 n = vslprintf(buf, buflen, fmt, args);
130 * vslprintf - like slprintf, takes a va_list instead of a list of args.
132 #define OUTCHAR(c) (buflen > 0? (--buflen, *buf++ = (c)): 0)
135 vslprintf(char *buf, int buflen, char *fmt, va_list args)
138 int width, prec, fillch;
139 int base, len, neg, quoted;
140 unsigned long val = 0;
141 char *str, *f, *buf0;
146 static char hexchars[] = "0123456789abcdef";
147 struct buffer_info bufinfo;
153 for (f = fmt; *f != '%' && *f != 0; ++f)
159 memcpy(buf, fmt, len);
175 width = va_arg(args, int);
179 width = width * 10 + c - '0';
186 prec = va_arg(args, int);
191 prec = prec * 10 + c - '0';
205 val = va_arg(args, long);
213 val = va_arg(args, unsigned long);
219 --fmt; /* so %lz outputs %lz etc. */
224 i = va_arg(args, int);
233 val = va_arg(args, unsigned int);
237 val = va_arg(args, unsigned int);
242 val = va_arg(args, unsigned int);
246 val = (unsigned long) va_arg(args, void *);
251 str = va_arg(args, char *);
254 num[0] = va_arg(args, int);
259 str = strerror(errno);
262 ip = va_arg(args, u_int32_t);
264 slprintf(num, sizeof(num), "%d.%d.%d.%d", (ip >> 24) & 0xff,
265 (ip >> 16) & 0xff, (ip >> 8) & 0xff, ip & 0xff);
271 str += 4; /* chop off the day name */
272 str[15] = 0; /* chop off year and newline */
274 case 'v': /* "visible" string */
275 case 'q': /* quoted string */
277 p = va_arg(args, unsigned char *);
279 p = (unsigned char *)"<NULL>";
280 if (fillch == '0' && prec >= 0) {
282 termch = -1; /* matches no unsigned char value */
285 if (prec != -1 && n > prec)
287 termch = 0; /* stop on null byte */
289 while (n > 0 && buflen > 0) {
294 if (!quoted && c >= 0x80) {
299 if (quoted && (c == '"' || c == '\\'))
301 if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
305 case '\t': OUTCHAR('t'); break;
306 case '\n': OUTCHAR('n'); break;
307 case '\b': OUTCHAR('b'); break;
308 case '\f': OUTCHAR('f'); break;
311 OUTCHAR(hexchars[c >> 4]);
312 OUTCHAR(hexchars[c & 0xf]);
326 case 'P': /* print PPP packet */
328 bufinfo.len = buflen + 1;
329 p = va_arg(args, unsigned char *);
330 n = va_arg(args, int);
331 format_packet(p, n, vslp_printer, &bufinfo);
333 buflen = bufinfo.len - 1;
336 p = va_arg(args, unsigned char *);
337 for (n = prec; n > 0; --n) {
341 OUTCHAR(hexchars[(c >> 4) & 0xf]);
342 OUTCHAR(hexchars[c & 0xf]);
348 --fmt; /* so %z outputs %z etc. */
353 str = num + sizeof(num);
355 while (str > num + neg) {
356 *--str = hexchars[val % base];
358 if (--prec <= 0 && val == 0)
370 len = num + sizeof(num) - 1 - str;
372 for (len = 0; len < buflen && (prec == -1 || len < prec); ++len)
379 if ((n = width - len) > 0) {
387 memcpy(buf, str, len);
396 * vslp_printer - used in processing a %P format
399 vslp_printer(void *arg, char *fmt, ...)
403 struct buffer_info *bi;
407 bi = (struct buffer_info *) arg;
408 n = vslprintf(bi->ptr, bi->len, fmt, pvar);
417 * log_packet - format a packet and log it.
421 log_packet(u_char *p, int len, char *prefix, int level)
423 init_pr_log(prefix, level);
424 format_packet(p, len, pr_log, &level);
430 * format_packet - make a readable representation of a packet,
431 * calling `printer(arg, format, ...)' to output it.
434 format_packet(u_char *p, int len, printer_func printer, void *arg)
438 struct protent *protp;
440 if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
444 for (i = 0; (protp = protocols[i]) != NULL; ++i)
445 if (proto == protp->protocol)
448 printer(arg, "[%s", protp->name);
449 n = (*protp->printpkt)(p, len, printer, arg);
454 for (i = 0; (protp = protocols[i]) != NULL; ++i)
455 if (proto == (protp->protocol & ~0x8000))
457 if (protp != 0 && protp->data_name != 0) {
458 printer(arg, "[%s data]", protp->data_name);
460 printer(arg, "%.8B ...", p);
462 printer(arg, "%.*B", len, p);
465 printer(arg, "[proto=0x%x]", proto);
470 printer(arg, "%.32B ...", p);
472 printer(arg, "%.*B", len, p);
476 * init_pr_log, end_pr_log - initialize and finish use of pr_log.
479 static char line[256]; /* line to be logged accumulated here */
480 static char *linep; /* current pointer within line */
481 static int llevel; /* level for logging */
484 init_pr_log(const char *prefix, int level)
487 if (prefix != NULL) {
488 strlcpy(line, prefix, sizeof(line));
489 linep = line + strlen(line);
499 log_write(llevel, line);
504 * pr_log - printer routine for outputting to syslog
507 pr_log(void *arg, char *fmt, ...)
516 n = vslprintf(buf, sizeof(buf), fmt, pvar);
520 eol = strchr(buf, '\n');
522 l = (eol == NULL)? n: eol - buf;
523 if (linep + l < line + sizeof(line)) {
525 memcpy(linep, buf, l);
531 eol = strchr(p, '\n');
534 log_write(llevel, line);
538 while (eol != NULL) {
540 log_write(llevel, p);
542 eol = strchr(p, '\n');
545 /* assumes sizeof(buf) <= sizeof(line) */
554 * print_string - print a readable representation of a string using
558 print_string(char *p, int len, printer_func printer, void *arg)
563 for (; len > 0; --len) {
565 if (' ' <= c && c <= '~') {
566 if (c == '\\' || c == '"')
568 printer(arg, "%c", c);
581 printer(arg, "\\%.3o", (unsigned char) c);
589 * logit - does the hard work for fatal et al.
592 logit(int level, char *fmt, va_list args)
596 vslprintf(buf, sizeof(buf), fmt, args);
597 log_write(level, buf);
601 log_write(int level, char *buf)
603 syslog(level, "%s", buf);
604 if (log_to_fd >= 0 && (level != LOG_DEBUG || debug)) {
607 if (n > 0 && buf[n-1] == '\n')
609 if (write(log_to_fd, buf, n) != n
610 || write(log_to_fd, "\n", 1) != 1)
616 * fatal - log an error message and die horribly.
619 fatal(char *fmt, ...)
625 logit(LOG_ERR, fmt, pvar);
628 die(1); /* as promised */
632 * error - log an error message.
635 error(char *fmt, ...)
641 logit(LOG_ERR, fmt, pvar);
647 * warn - log a warning message.
656 logit(LOG_WARNING, fmt, pvar);
661 * notice - log a notice-level message.
664 notice(char *fmt, ...)
670 logit(LOG_NOTICE, fmt, pvar);
675 * info - log an informational message.
684 logit(LOG_INFO, fmt, pvar);
689 * dbglog - log a debug message.
692 dbglog(char *fmt, ...)
698 logit(LOG_DEBUG, fmt, pvar);
703 * dump_packet - print out a packet in readable form if it is interesting.
704 * Assumes len >= PPP_HDRLEN.
707 dump_packet(const char *tag, unsigned char *p, int len)
715 * don't print LCP echo request/reply packets if debug <= 1
716 * and the link is up.
718 proto = (p[2] << 8) + p[3];
719 if (debug <= 1 && unsuccess == 0 && proto == PPP_LCP
720 && len >= PPP_HDRLEN + HEADERLEN) {
721 unsigned char *lcp = p + PPP_HDRLEN;
722 int l = (lcp[2] << 8) + lcp[3];
724 if ((lcp[0] == ECHOREQ || lcp[0] == ECHOREP)
725 && l >= HEADERLEN && l <= len - PPP_HDRLEN)
729 dbglog("%s %P", tag, p, len);
733 * complete_read - read a full `count' bytes from fd,
734 * unless end-of-file or an error other than EINTR is encountered.
737 complete_read(int fd, void *buf, size_t count)
743 for (done = 0; done < count; ) {
744 nb = read(fd, ptr, count - done);
746 if (errno == EINTR && !got_sigterm)
758 /* Procedures for locking the serial device using a lock file. */
761 #define LOCK_DIR "/var/lock"
764 #define LOCK_DIR "/var/spool/locks"
766 #define LOCK_DIR "/var/spool/lock"
769 #endif /* LOCK_DIR */
771 static char lock_file[MAXPATHLEN];
774 * lock - create a lock file for the named device
782 result = mklock (dev, (void *) 0);
784 strlcpy(lock_file, dev, sizeof(lock_file));
789 notice("Device %s is locked by pid %d", dev, result);
791 error("Can't create lock file %s", lock_file);
796 char lock_buffer[12];
802 if (stat(dev, &sbuf) < 0) {
803 error("Can't get device number for %s: %m", dev);
806 if ((sbuf.st_mode & S_IFMT) != S_IFCHR) {
807 error("Can't lock %s: not a character device", dev);
810 slprintf(lock_file, sizeof(lock_file), "%s/LK.%03d.%03d.%03d",
811 LOCK_DIR, major(sbuf.st_dev),
812 major(sbuf.st_rdev), minor(sbuf.st_rdev));
815 char lockdev[MAXPATHLEN];
817 if ((p = strstr(dev, "dev/")) != NULL) {
819 strncpy(lockdev, dev, MAXPATHLEN-1);
820 lockdev[MAXPATHLEN-1] = 0;
821 while ((p = strrchr(lockdev, '/')) != NULL) {
826 if ((p = strrchr(dev, '/')) != NULL)
829 slprintf(lock_file, sizeof(lock_file), "%s/LCK..%s", LOCK_DIR, dev);
832 while ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) < 0) {
833 if (errno != EEXIST) {
834 error("Can't create lock file %s: %m", lock_file);
838 /* Read the lock file to find out who has the device locked. */
839 fd = open(lock_file, O_RDONLY, 0);
841 if (errno == ENOENT) /* This is just a timing problem. */
843 error("Can't open existing lock file %s: %m", lock_file);
847 n = read(fd, lock_buffer, 11);
849 n = read(fd, &pid, sizeof(pid));
850 #endif /* LOCK_BINARY */
854 error("Can't read pid from lock file %s", lock_file);
858 /* See if the process still exists. */
861 pid = atoi(lock_buffer);
862 #endif /* LOCK_BINARY */
864 return 1; /* somebody else locked it for us */
866 || (kill(pid, 0) == -1 && errno == ESRCH)) {
867 if (unlink (lock_file) == 0) {
868 notice("Removed stale lock on %s (pid %d)", dev, pid);
871 warn("Couldn't remove stale lock on %s", dev);
873 notice("Device %s is locked by pid %d", dev, pid);
884 slprintf(lock_buffer, sizeof(lock_buffer), "%10d\n", pid);
885 write (fd, lock_buffer, 11);
887 write(fd, &pid, sizeof (pid));
896 * relock - called to update our lockfile when we are about to detach,
897 * thus changing our pid (we fork, the child carries on, and the parent dies).
898 * Note that this is called by the parent, with pid equal to the pid
899 * of the child. This avoids a potential race which would exist if
900 * we had the child rewrite the lockfile (the parent might die first,
901 * and another process could think the lock was stale if it checked
902 * between when the parent died and the child rewrote the lockfile).
908 /* XXX is there a way to do this? */
913 char lock_buffer[12];
915 if (lock_file[0] == 0)
917 fd = open(lock_file, O_WRONLY, 0);
919 error("Couldn't reopen lock file %s: %m", lock_file);
925 slprintf(lock_buffer, sizeof(lock_buffer), "%10d\n", pid);
926 write (fd, lock_buffer, 11);
928 write(fd, &pid, sizeof(pid));
929 #endif /* LOCK_BINARY */
937 * unlock - remove our lockfile
944 (void) rmlock(lock_file, (void *) 0);