+/*********************************************************************
+ *
+ * Function : pick_from_range
+ *
+ * Description : Pick a positive number out of a given range.
+ * Should only be used if randomness would be nice,
+ * but isn't really necessary.
+ *
+ * Parameters :
+ * 1 : range: Highest possible number to pick.
+ *
+ * Returns : Picked number.
+ *
+ *********************************************************************/
+long int pick_from_range(long int range)
+{
+ long int number;
+#ifdef _WIN32
+ static unsigned long seed = 0;
+#endif /* def _WIN32 */
+
+ assert(range != 0);
+ assert(range > 0);
+
+ if (range <= 0) return 0;
+
+#ifdef HAVE_ARC4RANDOM
+ number = arc4random() % range + 1;
+#elif defined(HAVE_RANDOM)
+ number = random() % range + 1;
+#elif defined(MUTEX_LOCKS_AVAILABLE)
+ privoxy_mutex_lock(&rand_mutex);
+#ifdef _WIN32
+ if (!seed)
+ {
+ seed = (unsigned long)(GetCurrentThreadId()+GetTickCount());
+ }
+ srand(seed);
+ seed = (unsigned long)((rand() << 16) + rand());
+#endif /* def _WIN32 */
+ number = (unsigned long)((rand() << 16) + (rand())) % (unsigned long)(range + 1);
+ privoxy_mutex_unlock(&rand_mutex);
+#else
+ /*
+ * XXX: Which platforms reach this and are there
+ * better options than just using rand() and hoping
+ * that it's safe?
+ */
+ log_error(LOG_LEVEL_INFO, "No thread-safe PRNG available? Header time randomization "
+ "might cause crashes, predictable results or even combine these fine options.");
+ number = rand() % (long int)(range + 1);
+
+#endif /* (def HAVE_ARC4RANDOM) */
+
+ return number;
+}
+
+
+#ifdef USE_PRIVOXY_STRLCPY
+/*********************************************************************
+ *
+ * Function : privoxy_strlcpy
+ *
+ * Description : strlcpy(3) look-alike for those without decent libc.
+ *
+ * Parameters :
+ * 1 : destination: buffer to copy into.
+ * 2 : source: String to copy.
+ * 3 : size: Size of destination buffer.
+ *
+ * Returns : The length of the string that privoxy_strlcpy() tried to create.
+ *
+ *********************************************************************/
+size_t privoxy_strlcpy(char *destination, const char *source, const size_t size)
+{
+ if (0 < size)
+ {
+ snprintf(destination, size, "%s", source);
+ /*
+ * Platforms that lack strlcpy() also tend to have
+ * a broken snprintf implementation that doesn't
+ * guarantee nul termination.
+ *
+ * XXX: the configure script should detect and reject those.
+ */
+ destination[size-1] = '\0';
+ }
+ return strlen(source);
+}
+#endif /* def USE_PRIVOXY_STRLCPY */
+
+
+#ifndef HAVE_STRLCAT
+/*********************************************************************
+ *
+ * Function : privoxy_strlcat
+ *
+ * Description : strlcat(3) look-alike for those without decent libc.
+ *
+ * Parameters :
+ * 1 : destination: C string.
+ * 2 : source: String to copy.
+ * 3 : size: Size of destination buffer.
+ *
+ * Returns : The length of the string that privoxy_strlcat() tried to create.
+ *
+ *********************************************************************/
+size_t privoxy_strlcat(char *destination, const char *source, const size_t size)
+{
+ const size_t old_length = strlen(destination);
+ return old_length + strlcpy(destination + old_length, source, size - old_length);
+}
+#endif /* ndef HAVE_STRLCAT */
+
+
+/*********************************************************************
+ *
+ * Function : privoxy_millisleep
+ *
+ * Description : Sleep a number of milliseconds
+ *
+ * Parameters :
+ * 1 : delay: Number of milliseconds to sleep
+ *
+ * Returns : -1 on error, 0 otherwise
+ *
+ *********************************************************************/
+int privoxy_millisleep(unsigned milliseconds)
+{
+#ifdef HAVE_NANOSLEEP
+ struct timespec rqtp = {0};
+ struct timespec rmtp = {0};
+
+ rqtp.tv_sec = milliseconds / 1000;
+ rqtp.tv_nsec = (milliseconds % 1000) * 1000 * 1000;
+
+ return nanosleep(&rqtp, &rmtp);
+#elif defined (_WIN32)
+ Sleep(milliseconds);
+
+ return 0;
+#else
+#warning Missing privoxy_milisleep() implementation. delay-response{} will not work.
+
+ return -1;
+#endif /* def HAVE_NANOSLEEP */
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : privoxy_gmtime_r
+ *
+ * Description : Behave like gmtime_r() and convert a
+ * time_t to a struct tm.
+ *
+ * Parameters :
+ * 1 : time_spec: The time to convert
+ * 2 : result: The struct tm to use as storage
+ *
+ * Returns : Pointer to the result or NULL on error.
+ *
+ *********************************************************************/
+struct tm *privoxy_gmtime_r(const time_t *time_spec, struct tm *result)
+{
+ struct tm *timeptr;
+
+#ifdef HAVE_GMTIME_R
+ timeptr = gmtime_r(time_spec, result);
+#elif defined(MUTEX_LOCKS_AVAILABLE)
+ privoxy_mutex_lock(&gmtime_mutex);
+ timeptr = gmtime(time_spec);
+#else
+#warning Using unlocked gmtime()
+ timeptr = gmtime(time_spec);
+#endif
+
+ if (timeptr == NULL)
+ {
+#if !defined(HAVE_GMTIME_R) && defined(MUTEX_LOCKS_AVAILABLE)
+ privoxy_mutex_unlock(&gmtime_mutex);
+#endif
+ return NULL;
+ }
+
+#if !defined(HAVE_GMTIME_R)
+ *result = *timeptr;
+ timeptr = result;
+#ifdef MUTEX_LOCKS_AVAILABLE
+ privoxy_mutex_unlock(&gmtime_mutex);
+#endif
+#endif
+
+ return timeptr;
+}
+
+#if !defined(HAVE_TIMEGM) && defined(HAVE_TZSET) && defined(HAVE_PUTENV)
+/*********************************************************************
+ *
+ * Function : timegm
+ *
+ * Description : libc replacement function for the inverse of gmtime().
+ * Copyright (C) 2004 Free Software Foundation, Inc.
+ *
+ * Code originally copied from GnuPG, modifications done
+ * for Privoxy: style changed, #ifdefs for _WIN32 added
+ * to have it work on mingw32.
+ *
+ * XXX: It's very unlikely to happen, but if the malloc()
+ * call fails the time zone will be permanently set to UTC.
+ *
+ * Parameters :
+ * 1 : tm: Broken-down time struct.
+ *
+ * Returns : tm converted into time_t seconds.
+ *
+ *********************************************************************/
+time_t timegm(struct tm *tm)
+{
+ time_t answer;
+ char *zone;
+
+ zone = getenv("TZ");
+ putenv("TZ=UTC");
+ tzset();
+ answer = mktime(tm);
+ if (zone)
+ {
+ char *old_zone;
+
+ old_zone = malloc(3 + strlen(zone) + 1);
+ if (old_zone)
+ {
+ strcpy(old_zone, "TZ=");
+ strcat(old_zone, zone);
+ putenv(old_zone);
+#ifdef _WIN32
+ /* http://man7.org/linux/man-pages/man3/putenv.3.html
+ * int putenv(char *string);
+ * The string pointed to by string becomes part of the environment, so altering the
+ * string changes the environment.
+ * In other words, the memory pointed to by *string is used until
+ * a) another call to putenv() with the same e-var name
+ * b) the program exits
+ *
+ * Windows e-vars don't work that way, so let's not leak memory.
+ */
+ free(old_zone);
+#endif /* def _WIN32 */
+ }
+ }
+ else
+ {
+#ifdef HAVE_UNSETENV
+ unsetenv("TZ");
+#elif defined(_WIN32)
+ putenv("TZ=");
+#else
+ putenv("TZ");
+#endif
+ }
+ tzset();
+
+ return answer;
+}
+#endif /* !defined(HAVE_TIMEGM) && defined(HAVE_TZSET) && defined(HAVE_PUTENV) */
+
+
+/*********************************************************************
+ *
+ * Function : host_is_ip_address
+ *
+ * Description : Checks whether or not a host is specified by
+ * IP address. Does not actually validate the
+ * address.
+ *
+ * Parameters :
+ * 1 : host = The host name to check
+ *
+ * Returns : 1 => Yes
+ * 0 => No
+ *
+ *********************************************************************/
+extern int host_is_ip_address(const char *host)
+{
+ const char *p;
+
+ if (NULL != strstr(host, ":"))
+ {
+ /* Assume an IPv6 address. */
+ return 1;
+ }
+
+ for (p = host; *p; p++)
+ {
+ if ((*p != '.') && !privoxy_isdigit(*p))
+ {
+ /* Not a dot or digit so it can't be an IPv4 address. */
+ return 0;
+ }
+ }
+
+ /*
+ * Host only consists of dots and digits so
+ * assume that is an IPv4 address.
+ */
+ return 1;
+
+}
+
+