/**
 * collectd - src/common.c
 * Copyright (C) 2005-2010  Florian octo Forster
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; only version 2 of the License is applicable.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 *
 * Authors:
 *   Florian octo Forster <octo at collectd.org>
 *   Niki W. Waibel <niki.waibel@gmx.net>
 *   Sebastian Harl <sh at tokkee.org>
 *   Michał Mirosław <mirq-linux at rere.qmqm.pl>
**/

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include "collectd.h"
#include "common.h"
#include "plugin.h"
#include "utils_cache.h"

#if HAVE_PTHREAD_H
# include <pthread.h>
#endif

#ifdef HAVE_MATH_H
# include <math.h>
#endif

/* for getaddrinfo */
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

#if HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

/* for ntohl and htonl */
#if HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif

#ifdef HAVE_LIBKSTAT
extern kstat_ctl_t *kc;
#endif

#if !HAVE_GETPWNAM_R
static pthread_mutex_t getpwnam_r_lock = PTHREAD_MUTEX_INITIALIZER;
#endif

#if !HAVE_STRERROR_R
static pthread_mutex_t strerror_r_lock = PTHREAD_MUTEX_INITIALIZER;
#endif

char *sstrncpy (char *dest, const char *src, size_t n)
{
	strncpy (dest, src, n);
	dest[n - 1] = '\0';

	return (dest);
} /* char *sstrncpy */

int ssnprintf (char *dest, size_t n, const char *format, ...)
{
	int ret = 0;
	va_list ap;

	va_start (ap, format);
	ret = vsnprintf (dest, n, format, ap);
	dest[n - 1] = '\0';
	va_end (ap);

	return (ret);
} /* int ssnprintf */

char *sstrdup (const char *s)
{
	char *r;
	size_t sz;

	if (s == NULL)
		return (NULL);

	/* Do not use `strdup' here, because it's not specified in POSIX. It's
	 * ``only'' an XSI extension. */
	sz = strlen (s) + 1;
	r = (char *) malloc (sizeof (char) * sz);
	if (r == NULL)
	{
		ERROR ("sstrdup: Out of memory.");
		exit (3);
	}
	memcpy (r, s, sizeof (char) * sz);

	return (r);
} /* char *sstrdup */

/* Even though Posix requires "strerror_r" to return an "int",
 * some systems (e.g. the GNU libc) return a "char *" _and_
 * ignore the second argument ... -tokkee */
char *sstrerror (int errnum, char *buf, size_t buflen)
{
	buf[0] = '\0';

#if !HAVE_STRERROR_R
	{
		char *temp;

		pthread_mutex_lock (&strerror_r_lock);

		temp = strerror (errnum);
		sstrncpy (buf, temp, buflen);

		pthread_mutex_unlock (&strerror_r_lock);
	}
/* #endif !HAVE_STRERROR_R */

#elif STRERROR_R_CHAR_P
	{
		char *temp;
		temp = strerror_r (errnum, buf, buflen);
		if (buf[0] == '\0')
		{
			if ((temp != NULL) && (temp != buf) && (temp[0] != '\0'))
				sstrncpy (buf, temp, buflen);
			else
				sstrncpy (buf, "strerror_r did not return "
						"an error message", buflen);
		}
	}
/* #endif STRERROR_R_CHAR_P */

#else
	if (strerror_r (errnum, buf, buflen) != 0)
	{
		ssnprintf (buf, buflen, "Error #%i; "
				"Additionally, strerror_r failed.",
				errnum);
	}
#endif /* STRERROR_R_CHAR_P */

	return (buf);
} /* char *sstrerror */

void *smalloc (size_t size)
{
	void *r;

	if ((r = malloc (size)) == NULL)
	{
		ERROR ("Not enough memory.");
		exit (3);
	}

	return (r);
} /* void *smalloc */

#if 0
void sfree (void **ptr)
{
	if (ptr == NULL)
		return;

	if (*ptr != NULL)
		free (*ptr);

	*ptr = NULL;
}
#endif

ssize_t sread (int fd, void *buf, size_t count)
{
	char    *ptr;
	size_t   nleft;
	ssize_t  status;

	ptr   = (char *) buf;
	nleft = count;

	while (nleft > 0)
	{
		status = read (fd, (void *) ptr, nleft);

		if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
			continue;

		if (status < 0)
			return (status);

		if (status == 0)
		{
			DEBUG ("Received EOF from fd %i. "
					"Closing fd and returning error.",
					fd);
			close (fd);
			return (-1);
		}

		assert ((0 > status) || (nleft >= (size_t)status));

		nleft = nleft - status;
		ptr   = ptr   + status;
	}

	return (0);
}


ssize_t swrite (int fd, const void *buf, size_t count)
{
	const char *ptr;
	size_t      nleft;
	ssize_t     status;

	ptr   = (const char *) buf;
	nleft = count;

	while (nleft > 0)
	{
		status = write (fd, (const void *) ptr, nleft);

		if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
			continue;

		if (status < 0)
			return (status);

		nleft = nleft - status;
		ptr   = ptr   + status;
	}

	return (0);
}

int strsplit (char *string, char **fields, size_t size)
{
	size_t i;
	char *ptr;
	char *saveptr;

	i = 0;
	ptr = string;
	saveptr = NULL;
	while ((fields[i] = strtok_r (ptr, " \t\r\n", &saveptr)) != NULL)
	{
		ptr = NULL;
		i++;

		if (i >= size)
			break;
	}

	return ((int) i);
}

int strjoin (char *dst, size_t dst_len,
		char **fields, size_t fields_num,
		const char *sep)
{
	size_t field_len;
	size_t sep_len;
	int i;

	memset (dst, '\0', dst_len);

	if (fields_num <= 0)
		return (-1);

	sep_len = 0;
	if (sep != NULL)
		sep_len = strlen (sep);

	for (i = 0; i < (int)fields_num; i++)
	{
		if ((i > 0) && (sep_len > 0))
		{
			if (dst_len <= sep_len)
				return (-1);

			strncat (dst, sep, dst_len);
			dst_len -= sep_len;
		}

		field_len = strlen (fields[i]);

		if (dst_len <= field_len)
			return (-1);

		strncat (dst, fields[i], dst_len);
		dst_len -= field_len;
	}

	return (strlen (dst));
}

int strsubstitute (char *str, char c_from, char c_to)
{
	int ret;

	if (str == NULL)
		return (-1);

	ret = 0;
	while (*str != '\0')
	{
		if (*str == c_from)
		{
			*str = c_to;
			ret++;
		}
		str++;
	}

	return (ret);
} /* int strsubstitute */

int strunescape (char *buf, size_t buf_len)
{
	size_t i;

	for (i = 0; (i < buf_len) && (buf[i] != '\0'); ++i)
	{
		if (buf[i] != '\\')
			continue;

		if ((i >= buf_len) || (buf[i + 1] == '\0')) {
			ERROR ("string unescape: backslash found at end of string.");
			return (-1);
		}

		switch (buf[i + 1]) {
			case 't':
				buf[i] = '\t';
				break;
			case 'n':
				buf[i] = '\n';
				break;
			case 'r':
				buf[i] = '\r';
				break;
			default:
				buf[i] = buf[i + 1];
				break;
		}

		memmove (buf + i + 1, buf + i + 2, buf_len - i - 2);
	}
	return (0);
} /* int strunescape */

size_t strstripnewline (char *buffer)
{
	size_t buffer_len = strlen (buffer);

	while (buffer_len > 0)
	{
		if ((buffer[buffer_len - 1] != '\n')
				&& (buffer[buffer_len - 1] != '\r'))
			break;
		buffer[buffer_len] = 0;
		buffer_len--;
	}

	return (buffer_len);
} /* size_t strstripnewline */

int escape_slashes (char *buf, int buf_len)
{
	int i;

	if (strcmp (buf, "/") == 0)
	{
		if (buf_len < 5)
			return (-1);

		strncpy (buf, "root", buf_len);
		return (0);
	}

	if (buf_len <= 1)
		return (0);

	/* Move one to the left */
	if (buf[0] == '/')
		memmove (buf, buf + 1, buf_len - 1);

	for (i = 0; i < buf_len - 1; i++)
	{
		if (buf[i] == '\0')
			break;
		else if (buf[i] == '/')
			buf[i] = '_';
	}
	buf[i] = '\0';

	return (0);
} /* int escape_slashes */

void replace_special (char *buffer, size_t buffer_size)
{
	size_t i;

	for (i = 0; i < buffer_size; i++)
	{
		if (buffer[i] == 0)
			return;
		if ((!isalnum ((int) buffer[i])) && (buffer[i] != '-'))
			buffer[i] = '_';
	}
} /* void replace_special */

int timeval_cmp (struct timeval tv0, struct timeval tv1, struct timeval *delta)
{
	struct timeval *larger;
	struct timeval *smaller;

	int status;

	NORMALIZE_TIMEVAL (tv0);
	NORMALIZE_TIMEVAL (tv1);

	if ((tv0.tv_sec == tv1.tv_sec) && (tv0.tv_usec == tv1.tv_usec))
	{
		if (delta != NULL) {
			delta->tv_sec  = 0;
			delta->tv_usec = 0;
		}
		return (0);
	}

	if ((tv0.tv_sec < tv1.tv_sec)
			|| ((tv0.tv_sec == tv1.tv_sec) && (tv0.tv_usec < tv1.tv_usec)))
	{
		larger  = &tv1;
		smaller = &tv0;
		status  = -1;
	}
	else
	{
		larger  = &tv0;
		smaller = &tv1;
		status  = 1;
	}

	if (delta != NULL) {
		delta->tv_sec = larger->tv_sec - smaller->tv_sec;

		if (smaller->tv_usec <= larger->tv_usec)
			delta->tv_usec = larger->tv_usec - smaller->tv_usec;
		else
		{
			--delta->tv_sec;
			delta->tv_usec = 1000000 + larger->tv_usec - smaller->tv_usec;
		}
	}

	assert ((delta == NULL)
			|| ((0 <= delta->tv_usec) && (delta->tv_usec < 1000000)));

	return (status);
} /* int timeval_cmp */

int check_create_dir (const char *file_orig)
{
	struct stat statbuf;

	char  file_copy[512];
	char  dir[512];
	int   dir_len = 512;
	char *fields[16];
	int   fields_num;
	char *ptr;
	char *saveptr;
	int   last_is_file = 1;
	int   path_is_absolute = 0;
	size_t len;
	int   i;

	/*
	 * Sanity checks first
	 */
	if (file_orig == NULL)
		return (-1);

	if ((len = strlen (file_orig)) < 1)
		return (-1);
	else if (len >= sizeof (file_copy))
		return (-1);

	/*
	 * If `file_orig' ends in a slash the last component is a directory,
	 * otherwise it's a file. Act accordingly..
	 */
	if (file_orig[len - 1] == '/')
		last_is_file = 0;
	if (file_orig[0] == '/')
		path_is_absolute = 1;

	/*
	 * Create a copy for `strtok_r' to destroy
	 */
	sstrncpy (file_copy, file_orig, sizeof (file_copy));

	/*
	 * Break into components. This will eat up several slashes in a row and
	 * remove leading and trailing slashes..
	 */
	ptr = file_copy;
	saveptr = NULL;
	fields_num = 0;
	while ((fields[fields_num] = strtok_r (ptr, "/", &saveptr)) != NULL)
	{
		ptr = NULL;
		fields_num++;

		if (fields_num >= 16)
			break;
	}

	/*
	 * For each component, do..
	 */
	for (i = 0; i < (fields_num - last_is_file); i++)
	{
		/*
		 * Do not create directories that start with a dot. This
		 * prevents `../../' attacks and other likely malicious
		 * behavior.
		 */
		if (fields[i][0] == '.')
		{
			ERROR ("Cowardly refusing to create a directory that "
					"begins with a `.' (dot): `%s'", file_orig);
			return (-2);
		}

		/*
		 * Join the components together again
		 */
		dir[0] = '/';
		if (strjoin (dir + path_is_absolute, dir_len - path_is_absolute,
					fields, i + 1, "/") < 0)
		{
			ERROR ("strjoin failed: `%s', component #%i", file_orig, i);
			return (-1);
		}

		while (42) {
			if ((stat (dir, &statbuf) == -1)
					&& (lstat (dir, &statbuf) == -1))
			{
				if (errno == ENOENT)
				{
					if (mkdir (dir, S_IRWXU | S_IRWXG | S_IRWXO) == 0)
						break;

					/* this might happen, if a different thread created
					 * the directory in the meantime
					 * => call stat() again to check for S_ISDIR() */
					if (EEXIST == errno)
						continue;

					char errbuf[1024];
					ERROR ("check_create_dir: mkdir (%s): %s", dir,
							sstrerror (errno,
								errbuf, sizeof (errbuf)));
					return (-1);
				}
				else
				{
					char errbuf[1024];
					ERROR ("check_create_dir: stat (%s): %s", dir,
							sstrerror (errno, errbuf,
								sizeof (errbuf)));
					return (-1);
				}
			}
			else if (!S_ISDIR (statbuf.st_mode))
			{
				ERROR ("check_create_dir: `%s' exists but is not "
						"a directory!", dir);
				return (-1);
			}
			break;
		}
	}

	return (0);
} /* check_create_dir */

#ifdef HAVE_LIBKSTAT
int get_kstat (kstat_t **ksp_ptr, char *module, int instance, char *name)
{
	char ident[128];

	*ksp_ptr = NULL;
	
	if (kc == NULL)
		return (-1);

	ssnprintf (ident, sizeof (ident), "%s,%i,%s", module, instance, name);

	*ksp_ptr = kstat_lookup (kc, module, instance, name);
	if (*ksp_ptr == NULL)
	{
		ERROR ("get_kstat: Cound not find kstat %s", ident);
		return (-1);
	}

	if ((*ksp_ptr)->ks_type != KSTAT_TYPE_NAMED)
	{
		ERROR ("get_kstat: kstat %s has wrong type", ident);
		*ksp_ptr = NULL;
		return (-1);
	}

#ifdef assert
	assert (*ksp_ptr != NULL);
	assert ((*ksp_ptr)->ks_type == KSTAT_TYPE_NAMED);
#endif

	if (kstat_read (kc, *ksp_ptr, NULL) == -1)
	{
		ERROR ("get_kstat: kstat %s could not be read", ident);
		return (-1);
	}

	if ((*ksp_ptr)->ks_type != KSTAT_TYPE_NAMED)
	{
		ERROR ("get_kstat: kstat %s has wrong type", ident);
		return (-1);
	}

	return (0);
}

long long get_kstat_value (kstat_t *ksp, char *name)
{
	kstat_named_t *kn;
	long long retval = -1LL;

	if (ksp == NULL)
	{
		ERROR ("get_kstat_value (\"%s\"): ksp is NULL.", name);
		return (-1LL);
	}
	else if (ksp->ks_type != KSTAT_TYPE_NAMED)
	{
		ERROR ("get_kstat_value (\"%s\"): ksp->ks_type (%#x) "
				"is not KSTAT_TYPE_NAMED (%#x).",
				name,
				(unsigned int) ksp->ks_type,
				(unsigned int) KSTAT_TYPE_NAMED);
		return (-1LL);
	}

	if ((kn = (kstat_named_t *) kstat_data_lookup (ksp, name)) == NULL)
		return (-1LL);

	if (kn->data_type == KSTAT_DATA_INT32)
		retval = (long long) kn->value.i32;
	else if (kn->data_type == KSTAT_DATA_UINT32)
		retval = (long long) kn->value.ui32;
	else if (kn->data_type == KSTAT_DATA_INT64)
		retval = (long long) kn->value.i64; /* According to ANSI C99 `long long' must hold at least 64 bits */
	else if (kn->data_type == KSTAT_DATA_UINT64)
		retval = (long long) kn->value.ui64; /* XXX: Might overflow! */
	else
		WARNING ("get_kstat_value: Not a numeric value: %s", name);

	return (retval);
}
#endif /* HAVE_LIBKSTAT */

#ifndef HAVE_HTONLL
unsigned long long ntohll (unsigned long long n)
{
#if BYTE_ORDER == BIG_ENDIAN
	return (n);
#else
	return (((unsigned long long) ntohl (n)) << 32) + ntohl (n >> 32);
#endif
} /* unsigned long long ntohll */

unsigned long long htonll (unsigned long long n)
{
#if BYTE_ORDER == BIG_ENDIAN
	return (n);
#else
	return (((unsigned long long) htonl (n)) << 32) + htonl (n >> 32);
#endif
} /* unsigned long long htonll */
#endif /* HAVE_HTONLL */

#if FP_LAYOUT_NEED_NOTHING
/* Well, we need nothing.. */
/* #endif FP_LAYOUT_NEED_NOTHING */

#elif FP_LAYOUT_NEED_ENDIANFLIP || FP_LAYOUT_NEED_INTSWAP
# if FP_LAYOUT_NEED_ENDIANFLIP
#  define FP_CONVERT(A) ((((uint64_t)(A) & 0xff00000000000000LL) >> 56) | \
                         (((uint64_t)(A) & 0x00ff000000000000LL) >> 40) | \
                         (((uint64_t)(A) & 0x0000ff0000000000LL) >> 24) | \
                         (((uint64_t)(A) & 0x000000ff00000000LL) >> 8)  | \
                         (((uint64_t)(A) & 0x00000000ff000000LL) << 8)  | \
                         (((uint64_t)(A) & 0x0000000000ff0000LL) << 24) | \
                         (((uint64_t)(A) & 0x000000000000ff00LL) << 40) | \
                         (((uint64_t)(A) & 0x00000000000000ffLL) << 56))
# else
#  define FP_CONVERT(A) ((((uint64_t)(A) & 0xffffffff00000000LL) >> 32) | \
                         (((uint64_t)(A) & 0x00000000ffffffffLL) << 32))
# endif

double ntohd (double d)
{
	union
	{
		uint8_t  byte[8];
		uint64_t integer;
		double   floating;
	} ret;

	ret.floating = d;

	/* NAN in x86 byte order */
	if ((ret.byte[0] == 0x00) && (ret.byte[1] == 0x00)
			&& (ret.byte[2] == 0x00) && (ret.byte[3] == 0x00)
			&& (ret.byte[4] == 0x00) && (ret.byte[5] == 0x00)
			&& (ret.byte[6] == 0xf8) && (ret.byte[7] == 0x7f))
	{
		return (NAN);
	}
	else
	{
		uint64_t tmp;

		tmp = ret.integer;
		ret.integer = FP_CONVERT (tmp);
		return (ret.floating);
	}
} /* double ntohd */

double htond (double d)
{
	union
	{
		uint8_t  byte[8];
		uint64_t integer;
		double   floating;
	} ret;

	if (isnan (d))
	{
		ret.byte[0] = ret.byte[1] = ret.byte[2] = ret.byte[3] = 0x00;
		ret.byte[4] = ret.byte[5] = 0x00;
		ret.byte[6] = 0xf8;
		ret.byte[7] = 0x7f;
		return (ret.floating);
	}
	else
	{
		uint64_t tmp;

		ret.floating = d;
		tmp = FP_CONVERT (ret.integer);
		ret.integer = tmp;
		return (ret.floating);
	}
} /* double htond */
#endif /* FP_LAYOUT_NEED_ENDIANFLIP || FP_LAYOUT_NEED_INTSWAP */

int format_name (char *ret, int ret_len,
		const char *hostname,
		const char *plugin, const char *plugin_instance,
		const char *type, const char *type_instance)
{
  char *buffer;
  size_t buffer_size;

  buffer = ret;
  buffer_size = (size_t) ret_len;

#define APPEND(str) do {                                               \
  size_t l = strlen (str);                                             \
  if (l >= buffer_size)                                                \
    return (ENOBUFS);                                                  \
  memcpy (buffer, (str), l);                                           \
  buffer += l; buffer_size -= l;                                       \
} while (0)

  assert (plugin != NULL);
  assert (type != NULL);

  APPEND (hostname);
  APPEND ("/");
  APPEND (plugin);
  if ((plugin_instance != NULL) && (plugin_instance[0] != 0))
  {
    APPEND ("-");
    APPEND (plugin_instance);
  }
  APPEND ("/");
  APPEND (type);
  if ((type_instance != NULL) && (type_instance[0] != 0))
  {
    APPEND ("-");
    APPEND (type_instance);
  }
  assert (buffer_size > 0);
  buffer[0] = 0;

#undef APPEND
  return (0);
} /* int format_name */

int format_values (char *ret, size_t ret_len, /* {{{ */
		const data_set_t *ds, const value_list_t *vl,
		_Bool store_rates)
{
        size_t offset = 0;
        int status;
        int i;
        gauge_t *rates = NULL;

        assert (0 == strcmp (ds->type, vl->type));

        memset (ret, 0, ret_len);

#define BUFFER_ADD(...) do { \
        status = ssnprintf (ret + offset, ret_len - offset, \
                        __VA_ARGS__); \
        if (status < 1) \
        { \
                sfree (rates); \
                return (-1); \
        } \
        else if (((size_t) status) >= (ret_len - offset)) \
        { \
                sfree (rates); \
                return (-1); \
        } \
        else \
                offset += ((size_t) status); \
} while (0)

        BUFFER_ADD ("%.3f", CDTIME_T_TO_DOUBLE (vl->time));

        for (i = 0; i < ds->ds_num; i++)
        {
                if (ds->ds[i].type == DS_TYPE_GAUGE)
                        BUFFER_ADD (":%f", vl->values[i].gauge);
                else if (store_rates)
                {
                        if (rates == NULL)
                                rates = uc_get_rate (ds, vl);
                        if (rates == NULL)
                        {
                                WARNING ("format_values: "
						"uc_get_rate failed.");
                                return (-1);
                        }
                        BUFFER_ADD (":%g", rates[i]);
                }
                else if (ds->ds[i].type == DS_TYPE_COUNTER)
                        BUFFER_ADD (":%llu", vl->values[i].counter);
                else if (ds->ds[i].type == DS_TYPE_DERIVE)
                        BUFFER_ADD (":%"PRIi64, vl->values[i].derive);
                else if (ds->ds[i].type == DS_TYPE_ABSOLUTE)
                        BUFFER_ADD (":%"PRIu64, vl->values[i].absolute);
                else
                {
                        ERROR ("format_values plugin: Unknown data source type: %i",
                                        ds->ds[i].type);
                        sfree (rates);
                        return (-1);
                }
        } /* for ds->ds_num */

#undef BUFFER_ADD

        sfree (rates);
        return (0);
} /* }}} int format_values */

int parse_identifier (char *str, char **ret_host,
		char **ret_plugin, char **ret_plugin_instance,
		char **ret_type, char **ret_type_instance)
{
	char *hostname = NULL;
	char *plugin = NULL;
	char *plugin_instance = NULL;
	char *type = NULL;
	char *type_instance = NULL;

	hostname = str;
	if (hostname == NULL)
		return (-1);

	plugin = strchr (hostname, '/');
	if (plugin == NULL)
		return (-1);
	*plugin = '\0'; plugin++;

	type = strchr (plugin, '/');
	if (type == NULL)
		return (-1);
	*type = '\0'; type++;

	plugin_instance = strchr (plugin, '-');
	if (plugin_instance != NULL)
	{
		*plugin_instance = '\0';
		plugin_instance++;
	}

	type_instance = strchr (type, '-');
	if (type_instance != NULL)
	{
		*type_instance = '\0';
		type_instance++;
	}

	*ret_host = hostname;
	*ret_plugin = plugin;
	*ret_plugin_instance = plugin_instance;
	*ret_type = type;
	*ret_type_instance = type_instance;
	return (0);
} /* int parse_identifier */

int parse_identifier_vl (const char *str, value_list_t *vl) /* {{{ */
{
	char str_copy[6 * DATA_MAX_NAME_LEN];
	char *host = NULL;
	char *plugin = NULL;
	char *plugin_instance = NULL;
	char *type = NULL;
	char *type_instance = NULL;
	int status;

	if ((str == NULL) || (vl == NULL))
		return (EINVAL);

	sstrncpy (str_copy, str, sizeof (str_copy));

	status = parse_identifier (str_copy, &host,
			&plugin, &plugin_instance,
			&type, &type_instance);
	if (status != 0)
		return (status);

	sstrncpy (vl->host, host, sizeof (vl->host));
	sstrncpy (vl->plugin, plugin, sizeof (vl->plugin));
	sstrncpy (vl->plugin_instance,
			(plugin_instance != NULL) ? plugin_instance : "",
			sizeof (vl->plugin_instance));
	sstrncpy (vl->type, type, sizeof (vl->type));
	sstrncpy (vl->type_instance,
			(type_instance != NULL) ? type_instance : "",
			sizeof (vl->type_instance));

	return (0);
} /* }}} int parse_identifier_vl */

int parse_value (const char *value_orig, value_t *ret_value, int ds_type)
{
  char *value;
  char *endptr = NULL;
  size_t value_len;

  if (value_orig == NULL)
    return (EINVAL);

  value = strdup (value_orig);
  if (value == NULL)
    return (ENOMEM);
  value_len = strlen (value);

  while ((value_len > 0) && isspace ((int) value[value_len - 1]))
  {
    value[value_len - 1] = 0;
    value_len--;
  }

  switch (ds_type)
  {
    case DS_TYPE_COUNTER:
      ret_value->counter = (counter_t) strtoull (value, &endptr, 0);
      break;

    case DS_TYPE_GAUGE:
      ret_value->gauge = (gauge_t) strtod (value, &endptr);
      break;

    case DS_TYPE_DERIVE:
      ret_value->derive = (derive_t) strtoll (value, &endptr, 0);
      break;

    case DS_TYPE_ABSOLUTE:
      ret_value->absolute = (absolute_t) strtoull (value, &endptr, 0);
      break;

    default:
      sfree (value);
      ERROR ("parse_value: Invalid data source type: %i.", ds_type);
      return -1;
  }

  if (value == endptr) {
    sfree (value);
    ERROR ("parse_value: Failed to parse string as %s: %s.",
        DS_TYPE_TO_STRING (ds_type), value);
    return -1;
  }
  else if ((NULL != endptr) && ('\0' != *endptr))
    INFO ("parse_value: Ignoring trailing garbage \"%s\" after %s value. "
        "Input string was \"%s\".",
        endptr, DS_TYPE_TO_STRING (ds_type), value_orig);

  sfree (value);
  return 0;
} /* int parse_value */

int parse_values (char *buffer, value_list_t *vl, const data_set_t *ds)
{
	int i;
	char *dummy;
	char *ptr;
	char *saveptr;

	i = -1;
	dummy = buffer;
	saveptr = NULL;
	while ((ptr = strtok_r (dummy, ":", &saveptr)) != NULL)
	{
		dummy = NULL;

		if (i >= vl->values_len)
		{
			/* Make sure i is invalid. */
			i = vl->values_len + 1;
			break;
		}

		if (i == -1)
		{
			if (strcmp ("N", ptr) == 0)
				vl->time = cdtime ();
			else
			{
				char *endptr = NULL;
				double tmp;

				errno = 0;
				tmp = strtod (ptr, &endptr);
				if ((errno != 0)                    /* Overflow */
						|| (endptr == ptr)  /* Invalid string */
						|| (endptr == NULL) /* This should not happen */
						|| (*endptr != 0))  /* Trailing chars */
					return (-1);

				vl->time = DOUBLE_TO_CDTIME_T (tmp);
			}
		}
		else
		{
			if ((strcmp ("U", ptr) == 0) && (ds->ds[i].type == DS_TYPE_GAUGE))
				vl->values[i].gauge = NAN;
			else if (0 != parse_value (ptr, &vl->values[i], ds->ds[i].type))
				return -1;
		}

		i++;
	} /* while (strtok_r) */

	if ((ptr != NULL) || (i != vl->values_len))
		return (-1);
	return (0);
} /* int parse_values */

#if !HAVE_GETPWNAM_R
int getpwnam_r (const char *name, struct passwd *pwbuf, char *buf,
		size_t buflen, struct passwd **pwbufp)
{
	int status = 0;
	struct passwd *pw;

	memset (pwbuf, '\0', sizeof (struct passwd));

	pthread_mutex_lock (&getpwnam_r_lock);

	do
	{
		pw = getpwnam (name);
		if (pw == NULL)
		{
			status = (errno != 0) ? errno : ENOENT;
			break;
		}

#define GETPWNAM_COPY_MEMBER(member) \
		if (pw->member != NULL) \
		{ \
			int len = strlen (pw->member); \
			if (len >= buflen) \
			{ \
				status = ENOMEM; \
				break; \
			} \
			sstrncpy (buf, pw->member, buflen); \
			pwbuf->member = buf; \
			buf    += (len + 1); \
			buflen -= (len + 1); \
		}
		GETPWNAM_COPY_MEMBER(pw_name);
		GETPWNAM_COPY_MEMBER(pw_passwd);
		GETPWNAM_COPY_MEMBER(pw_gecos);
		GETPWNAM_COPY_MEMBER(pw_dir);
		GETPWNAM_COPY_MEMBER(pw_shell);

		pwbuf->pw_uid = pw->pw_uid;
		pwbuf->pw_gid = pw->pw_gid;

		if (pwbufp != NULL)
			*pwbufp = pwbuf;
	} while (0);

	pthread_mutex_unlock (&getpwnam_r_lock);

	return (status);
} /* int getpwnam_r */
#endif /* !HAVE_GETPWNAM_R */

int notification_init (notification_t *n, int severity, const char *message,
		const char *host,
		const char *plugin, const char *plugin_instance,
		const char *type, const char *type_instance)
{
	memset (n, '\0', sizeof (notification_t));

	n->severity = severity;

	if (message != NULL)
		sstrncpy (n->message, message, sizeof (n->message));
	if (host != NULL)
		sstrncpy (n->host, host, sizeof (n->host));
	if (plugin != NULL)
		sstrncpy (n->plugin, plugin, sizeof (n->plugin));
	if (plugin_instance != NULL)
		sstrncpy (n->plugin_instance, plugin_instance,
				sizeof (n->plugin_instance));
	if (type != NULL)
		sstrncpy (n->type, type, sizeof (n->type));
	if (type_instance != NULL)
		sstrncpy (n->type_instance, type_instance,
				sizeof (n->type_instance));

	return (0);
} /* int notification_init */

int walk_directory (const char *dir, dirwalk_callback_f callback,
		void *user_data, int include_hidden)
{
	struct dirent *ent;
	DIR *dh;
	int success;
	int failure;

	success = 0;
	failure = 0;

	if ((dh = opendir (dir)) == NULL)
	{
		char errbuf[1024];
		ERROR ("walk_directory: Cannot open '%s': %s", dir,
				sstrerror (errno, errbuf, sizeof (errbuf)));
		return -1;
	}

	while ((ent = readdir (dh)) != NULL)
	{
		int status;
		
		if (include_hidden)
		{
			if ((strcmp (".", ent->d_name) == 0)
					|| (strcmp ("..", ent->d_name) == 0))
				continue;
		}
		else /* if (!include_hidden) */
		{
			if (ent->d_name[0]=='.')
				continue;
		}

		status = (*callback) (dir, ent->d_name, user_data);
		if (status != 0)
			failure++;
		else
			success++;
	}

	closedir (dh);

	if ((success == 0) && (failure > 0))
		return (-1);
	return (0);
}

int read_file_contents (const char *filename, char *buf, int bufsize)
{
	FILE *fh;
	int n;

	if ((fh = fopen (filename, "r")) == NULL)
		return -1;

	n = fread(buf, 1, bufsize, fh);
	fclose(fh);

	return n;
}

counter_t counter_diff (counter_t old_value, counter_t new_value)
{
	counter_t diff;

	if (old_value > new_value)
	{
		if (old_value <= 4294967295U)
			diff = (4294967295U - old_value) + new_value;
		else
			diff = (18446744073709551615ULL - old_value)
				+ new_value;
	}
	else
	{
		diff = new_value - old_value;
	}

	return (diff);
} /* counter_t counter_diff */

int rate_to_value (value_t *ret_value, gauge_t rate, /* {{{ */
		rate_to_value_state_t *state,
		int ds_type, cdtime_t t)
{
	gauge_t delta_gauge;
	cdtime_t delta_t;

	if (ds_type == DS_TYPE_GAUGE)
	{
		state->last_value.gauge = rate;
		state->last_time = t;

		*ret_value = state->last_value;
		return (0);
	}

	/* Counter and absolute can't handle negative rates. Reset "last time"
	 * to zero, so that the next valid rate will re-initialize the
	 * structure. */
	if ((rate < 0.0)
			&& ((ds_type == DS_TYPE_COUNTER)
				|| (ds_type == DS_TYPE_ABSOLUTE)))
	{
		memset (state, 0, sizeof (*state));
		return (EINVAL);
	}

	/* Another invalid state: The time is not increasing. */
	if (t <= state->last_time)
	{
		memset (state, 0, sizeof (*state));
		return (EINVAL);
	}

	delta_t = t - state->last_time;
	delta_gauge = (rate * CDTIME_T_TO_DOUBLE (delta_t)) + state->residual;

	/* Previous value is invalid. */
	if (state->last_time == 0) /* {{{ */
	{
		if (ds_type == DS_TYPE_DERIVE)
		{
			state->last_value.derive = (derive_t) rate;
			state->residual = rate - ((gauge_t) state->last_value.derive);
		}
		else if (ds_type == DS_TYPE_COUNTER)
		{
			state->last_value.counter = (counter_t) rate;
			state->residual = rate - ((gauge_t) state->last_value.counter);
		}
		else if (ds_type == DS_TYPE_ABSOLUTE)
		{
			state->last_value.absolute = (absolute_t) rate;
			state->residual = rate - ((gauge_t) state->last_value.absolute);
		}
		else
		{
			assert (23 == 42);
		}

		state->last_time = t;
		return (EAGAIN);
	} /* }}} */

	if (ds_type == DS_TYPE_DERIVE)
	{
		derive_t delta_derive = (derive_t) delta_gauge;

		state->last_value.derive += delta_derive;
		state->residual = delta_gauge - ((gauge_t) delta_derive);
	}
	else if (ds_type == DS_TYPE_COUNTER)
	{
		counter_t delta_counter = (counter_t) delta_gauge;

		state->last_value.counter += delta_counter;
		state->residual = delta_gauge - ((gauge_t) delta_counter);
	}
	else if (ds_type == DS_TYPE_ABSOLUTE)
	{
		absolute_t delta_absolute = (absolute_t) delta_gauge;

		state->last_value.absolute = delta_absolute;
		state->residual = delta_gauge - ((gauge_t) delta_absolute);
	}
	else
	{
		assert (23 == 42);
	}

        state->last_time = t;
	*ret_value = state->last_value;
	return (0);
} /* }}} value_t rate_to_value */

int service_name_to_port_number (const char *service_name)
{
	struct addrinfo *ai_list;
	struct addrinfo *ai_ptr;
	struct addrinfo ai_hints;
	int status;
	int service_number;

	if (service_name == NULL)
		return (-1);

	ai_list = NULL;
	memset (&ai_hints, 0, sizeof (ai_hints));
	ai_hints.ai_family = AF_UNSPEC;

	status = getaddrinfo (/* node = */ NULL, service_name,
			&ai_hints, &ai_list);
	if (status != 0)
	{
		ERROR ("service_name_to_port_number: getaddrinfo failed: %s",
				gai_strerror (status));
		return (-1);
	}

	service_number = -1;
	for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
	{
		if (ai_ptr->ai_family == AF_INET)
		{
			struct sockaddr_in *sa;

			sa = (void *) ai_ptr->ai_addr;
			service_number = (int) ntohs (sa->sin_port);
		}
		else if (ai_ptr->ai_family == AF_INET6)
		{
			struct sockaddr_in6 *sa;

			sa = (void *) ai_ptr->ai_addr;
			service_number = (int) ntohs (sa->sin6_port);
		}

		if ((service_number > 0) && (service_number <= 65535))
			break;
	}

	freeaddrinfo (ai_list);

	if ((service_number > 0) && (service_number <= 65535))
		return (service_number);
	return (-1);
} /* int service_name_to_port_number */

int strtoderive (const char *string, derive_t *ret_value) /* {{{ */
{
	derive_t tmp;
	char *endptr;

	if ((string == NULL) || (ret_value == NULL))
		return (EINVAL);

	errno = 0;
	endptr = NULL;
	tmp = (derive_t) strtoll (string, &endptr, /* base = */ 0);
	if ((endptr == string) || (errno != 0))
		return (-1);

	*ret_value = tmp;
	return (0);
} /* }}} int strtoderive */

int strarray_add (char ***ret_array, size_t *ret_array_len, char const *str) /* {{{ */
{
	char **array;
	size_t array_len = *ret_array_len;

	if (str == NULL)
		return (EINVAL);

	array = realloc (*ret_array,
            (array_len + 1) * sizeof (*array));
	if (array == NULL)
		return (ENOMEM);
	*ret_array = array;

	array[array_len] = strdup (str);
	if (array[array_len] == NULL)
		return (ENOMEM);

	array_len++;
        *ret_array_len = array_len;
	return (0);
} /* }}} int strarray_add */

void strarray_free (char **array, size_t array_len) /* {{{ */
{
	size_t i;

	for (i = 0; i < array_len; i++)
		sfree (array[i]);
	sfree (array);
} /* }}} void strarray_free */
