/**
* collectd - src/sensors.c
- * Copyright (C) 2005,2006 Florian octo Forster
+ * Copyright (C) 2005-2007 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; either version 2 of the License, or (at your
- * option) any later version.
+ * 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
#include "plugin.h"
#include "configfile.h"
#include "utils_ignorelist.h"
-#include "utils_debug.h"
-
-#define MODULE_NAME "sensors"
-#define MODULE_NAME_VOLTAGE MODULE_NAME"_voltage"
#if defined(HAVE_SENSORS_SENSORS_H)
# include <sensors/sensors.h>
-#else
-# undef HAVE_LIBSENSORS
#endif
-#if defined(HAVE_LIBSENSORS)
-# define SENSORS_HAVE_READ 1
-#else
-# define SENSORS_HAVE_READ 0
+#if !defined(SENSORS_API_VERSION)
+# define SENSORS_API_VERSION 0x000
#endif
-#define BUFSIZE 512
-
-/* temperature and fan sensors */
-static char *ds_def[] =
-{
- "DS:value:GAUGE:"COLLECTD_HEARTBEAT":U:U",
- NULL
-};
-static int ds_num = 1;
-
-/* voltage sensors */
-static char *sensor_voltage_ds_def[] =
-{
- "DS:voltage:GAUGE:"COLLECTD_HEARTBEAT":U:U",
- NULL
-};
-static int sensor_voltage_ds_num = 1;
-
-/* old naming */
-static char *old_filename_format = "sensors-%s.rrd";
-/* end old naming */
-
-/* new naming <chip-bus-address/type-feature */
-static char *extended_filename_format = "lm_sensors-%s.rrd";
-
-#define SENSOR_TYPE_UNKNOWN 0
-#define SENSOR_TYPE_VOLTAGE 1
-#define SENSOR_TYPE_FANSPEED 2
-#define SENSOR_TYPE_TEMPERATURE 3
-
-#if SENSORS_HAVE_READ
-static char *sensor_type_prefix[] =
+/*
+ * The sensors library prior to version 3.0 (internal version 0x400) didn't
+ * report the type of values, only a name. The following lists are there to
+ * convert from the names to the type. They are not used with the new
+ * interface.
+ */
+#if SENSORS_API_VERSION < 0x400
+static char *sensor_type_name_map[] =
{
- "unknown",
+# define SENSOR_TYPE_VOLTAGE 0
"voltage",
+# define SENSOR_TYPE_FANSPEED 1
"fanspeed",
+# define SENSOR_TYPE_TEMPERATURE 2
"temperature",
+# define SENSOR_TYPE_UNKNOWN 3
NULL
};
-#endif
-typedef struct sensors_labeltypes {
+struct sensors_labeltypes_s
+{
char *label;
int type;
-} sensors_labeltypes;
+};
+typedef struct sensors_labeltypes_s sensors_labeltypes_t;
-/*
- * finite list of known labels extracted from lm_sensors
- */
-#if SENSORS_HAVE_READ
-static sensors_labeltypes known_features[] =
+/* finite list of known labels extracted from lm_sensors */
+static sensors_labeltypes_t known_features[] =
{
{ "fan1", SENSOR_TYPE_FANSPEED },
{ "fan2", SENSOR_TYPE_FANSPEED },
{ "3.3V", SENSOR_TYPE_VOLTAGE },
{ "2.5V", SENSOR_TYPE_VOLTAGE },
{ "2.0V", SENSOR_TYPE_VOLTAGE },
- { "12V", SENSOR_TYPE_VOLTAGE },
- { 0, -1 }
+ { "12V", SENSOR_TYPE_VOLTAGE }
};
-#endif
+static int known_features_num = STATIC_ARRAY_SIZE (known_features);
/* end new naming */
+#endif /* SENSORS_API_VERSION < 0x400 */
-static char *config_keys[] =
+static const char *config_keys[] =
{
"Sensor",
- "IgnoreSelected",
- "ExtendedSensorNaming",
- NULL
+ "IgnoreSelected"
};
-static int config_keys_num = 3;
-
-static ignorelist_t *sensor_list;
-
-/*
- * sensor_extended_naming:
- * 0 => default is to create chip-feature
- * 1 => use new naming scheme chip-bus-address/type-feature
- */
-static int sensor_extended_naming = 0;
-
-#if SENSORS_HAVE_READ
-# ifndef SENSORS_CONF_PATH
-# define SENSORS_CONF_PATH "/etc/sensors.conf"
-# endif
-
-static const char *conffile = SENSORS_CONF_PATH;
-/* SENSORS_CONF_PATH */
-
-/*
- * remember stat of the loaded config
- */
-static time_t sensors_config_mtime = 0;
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
+#if SENSORS_API_VERSION < 0x400
typedef struct featurelist
{
const sensors_chip_name *chip;
struct featurelist *next;
} featurelist_t;
+# ifndef SENSORS_CONF_PATH
+# define SENSORS_CONF_PATH "/etc/sensors.conf"
+# endif
+/* #endif SENSORS_API_VERSION < 0x400 */
+
+#elif (SENSORS_API_VERSION >= 0x400) && (SENSORS_API_VERSION < 0x500)
+typedef struct featurelist
+{
+ const sensors_chip_name *chip;
+ const sensors_feature *feature;
+ const sensors_subfeature *subfeature;
+ struct featurelist *next;
+} featurelist_t;
+
+# ifndef SENSORS_CONF_PATH
+# define SENSORS_CONF_PATH "/etc/sensors3.conf"
+# endif
+/* #endif (SENSORS_API_VERSION >= 0x400) && (SENSORS_API_VERSION < 0x500) */
+
+#else /* if SENSORS_API_VERSION >= 0x500 */
+# error "This version of libsensors is not supported yet. Please report this " \
+ "as bug."
+#endif
+
+static const char *conffile = SENSORS_CONF_PATH;
featurelist_t *first_feature = NULL;
-#endif /* if SENSORS_HAVE_READ */
+static ignorelist_t *sensor_list;
+static time_t sensors_config_mtime = 0;
-static int sensors_config (char *key, char *value)
+#if SENSORS_API_VERSION < 0x400
+/* full chip name logic borrowed from lm_sensors */
+static int sensors_snprintf_chip_name (char *buf, size_t buf_size,
+ const sensors_chip_name *chip)
+{
+ int status = -1;
+
+ if (chip->bus == SENSORS_CHIP_NAME_BUS_ISA)
+ {
+ status = snprintf (buf, buf_size,
+ "%s-isa-%04x",
+ chip->prefix,
+ chip->addr);
+ }
+ else if (chip->bus == SENSORS_CHIP_NAME_BUS_DUMMY)
+ {
+ snprintf (buf, buf_size, "%s-%s-%04x",
+ chip->prefix,
+ chip->busname,
+ chip->addr);
+ }
+ else
+ {
+ snprintf (buf, buf_size, "%s-i2c-%d-%02x",
+ chip->prefix,
+ chip->bus,
+ chip->addr);
+ }
+
+ return (status);
+} /* int sensors_snprintf_chip_name */
+
+static int sensors_feature_name_to_type (const char *name)
+{
+ int i;
+
+ /* Yes, this is slow, but it's only ever done during initialization, so
+ * it's a one time cost.. */
+ for (i = 0; i < known_features_num; i++)
+ if (strcasecmp (known_features[i].label, name) == 0)
+ return (known_features[i].type);
+
+ return (SENSOR_TYPE_UNKNOWN);
+} /* int sensors_feature_name_to_type */
+#endif
+
+static int sensors_config (const char *key, const char *value)
{
if (sensor_list == NULL)
sensor_list = ignorelist_create (1);
{
if (ignorelist_add (sensor_list, value))
{
- syslog (LOG_EMERG, MODULE_NAME": Cannot add value to ignorelist.");
+ ERROR ("sensors plugin: "
+ "Cannot add value to ignorelist.");
return (1);
}
}
|| (strcasecmp (value, "On") == 0))
ignorelist_set_invert (sensor_list, 0);
}
- else if (strcasecmp (key, "ExtendedSensorNaming") == 0)
- {
- if ((strcasecmp (value, "True") == 0)
- || (strcasecmp (value, "Yes") == 0)
- || (strcasecmp (value, "On") == 0))
- sensor_extended_naming = 1;
- else
- sensor_extended_naming = 0;
- }
else
{
return (-1);
return (0);
}
-#if SENSORS_HAVE_READ
void sensors_free_features (void)
{
featurelist_t *thisft;
first_feature = NULL;
}
-static void sensors_load_conf (void)
+static int sensors_load_conf (void)
{
FILE *fh;
featurelist_t *last_feature = NULL;
- featurelist_t *new_feature = NULL;
const sensors_chip_name *chip;
int chip_num;
- const sensors_feature_data *data;
- int data_num0, data_num1;
-
struct stat statbuf;
int status;
status = stat (conffile, &statbuf);
if (status != 0)
{
- syslog (LOG_ERR, MODULE_NAME": stat(%s) failed: %s",
- conffile, strerror (errno));
+ char errbuf[1024];
+ ERROR ("sensors plugin: stat (%s) failed: %s", conffile,
+ sstrerror (errno, errbuf, sizeof (errbuf)));
sensors_config_mtime = 0;
}
if ((sensors_config_mtime != 0)
&& (sensors_config_mtime == statbuf.st_mtime))
- return;
+ return (0);
if (sensors_config_mtime != 0)
{
- syslog (LOG_NOTICE, MODULE_NAME": Reloading config from %s",
+ NOTICE ("sensors plugin: Reloading config from %s",
conffile);
sensors_free_features ();
sensors_config_mtime = 0;
fh = fopen (conffile, "r");
if (fh == NULL)
{
- syslog (LOG_ERR, MODULE_NAME": fopen(%s) failed: %s",
- conffile, strerror(errno));
- return;
+ char errbuf[1024];
+ ERROR ("sensors plugin: fopen(%s) failed: %s", conffile,
+ sstrerror (errno, errbuf, sizeof (errbuf)));
+ return (-1);
}
status = sensors_init (fh);
fclose (fh);
if (status != 0)
{
- syslog (LOG_ERR, MODULE_NAME": Cannot initialize sensors. "
+ ERROR ("sensors plugin: Cannot initialize sensors. "
"Data will not be collected.");
- return;
+ return (-1);
}
sensors_config_mtime = statbuf.st_mtime;
+#if SENSORS_API_VERSION < 0x400
chip_num = 0;
while ((chip = sensors_get_detected_chips (&chip_num)) != NULL)
{
- data = NULL;
- data_num0 = data_num1 = 0;
+ int feature_num0 = 0;
+ int feature_num1 = 0;
- while ((data = sensors_get_all_features (*chip, &data_num0, &data_num1))
- != NULL)
+ while (42)
{
- int i;
+ const sensors_feature_data *feature;
+ int feature_type;
+ featurelist_t *fl;
+
+ feature = sensors_get_all_features (*chip,
+ &feature_num0, &feature_num1);
+
+ /* Check if all features have been read. */
+ if (feature == NULL)
+ break;
/* "master features" only */
- if (data->mapping != SENSORS_NO_MAPPING)
+ if (feature->mapping != SENSORS_NO_MAPPING)
continue;
- /* Only known features */
- for (i = 0; known_features[i].type >= 0; i++)
+ /* skip ignored in sensors.conf */
+ if (sensors_get_ignored (*chip, feature->number) == 0)
+ break;
+
+ feature_type = sensors_feature_name_to_type (
+ feature->name);
+ if (feature_type == SENSOR_TYPE_UNKNOWN)
+ continue;
+
+ fl = (featurelist_t *) malloc (sizeof (featurelist_t));
+ if (fl == NULL)
{
- if (strcmp (data->name, known_features[i].label) != 0)
- continue;
+ ERROR ("sensors plugin: malloc failed.");
+ continue;
+ }
+ memset (fl, '\0', sizeof (featurelist_t));
- /* skip ignored in sensors.conf */
- if (sensors_get_ignored (*chip, data->number) == 0)
- break;
+ fl->chip = chip;
+ fl->data = feature;
+ fl->type = feature_type;
- DBG ("Adding feature: %s-%s-%s",
- chip->prefix,
- sensor_type_prefix[known_features[i].type],
- data->name);
+ if (first_feature == NULL)
+ first_feature = fl;
+ else
+ last_feature->next = fl;
+ last_feature = fl;
+ } /* while sensors_get_all_features */
+ } /* while sensors_get_detected_chips */
+/* #endif SENSORS_API_VERSION < 0x400 */
- if ((new_feature = (featurelist_t *) malloc (sizeof (featurelist_t))) == NULL)
+#elif (SENSORS_API_VERSION >= 0x400) && (SENSORS_API_VERSION < 0x500)
+ chip_num = 0;
+ while ((chip = sensors_get_detected_chips (NULL, &chip_num)) != NULL)
+ {
+ const sensors_feature *feature;
+ int feature_num = 0;
+
+ while ((feature = sensors_get_features (chip, &feature_num)) != NULL)
+ {
+ const sensors_subfeature *subfeature;
+ int subfeature_num = 0;
+
+ /* Only handle voltage, fanspeeds and temperatures */
+ if ((feature->type != SENSORS_FEATURE_IN)
+ && (feature->type != SENSORS_FEATURE_FAN)
+ && (feature->type != SENSORS_FEATURE_TEMP))
+ continue;
+
+ while ((subfeature = sensors_get_all_subfeatures (chip,
+ feature, &subfeature_num)) != NULL)
+ {
+ featurelist_t *fl;
+
+ if ((subfeature->type != SENSORS_SUBFEATURE_IN_INPUT)
+ && (subfeature->type != SENSORS_SUBFEATURE_FAN_INPUT)
+ && (subfeature->type != SENSORS_SUBFEATURE_TEMP_INPUT))
+ continue;
+
+ fl = (featurelist_t *) malloc (sizeof (featurelist_t));
+ if (fl == NULL)
{
- DBG ("malloc: %s", strerror (errno));
- syslog (LOG_ERR, MODULE_NAME": malloc: %s",
- strerror (errno));
- break;
+ ERROR ("sensors plugin: malloc failed.");
+ continue;
}
+ memset (fl, '\0', sizeof (featurelist_t));
- new_feature->chip = chip;
- new_feature->data = data;
- new_feature->type = known_features[i].type;
- new_feature->next = NULL;
+ fl->chip = chip;
+ fl->feature = feature;
+ fl->subfeature = subfeature;
if (first_feature == NULL)
- {
- first_feature = new_feature;
- last_feature = new_feature;
- }
+ first_feature = fl;
else
- {
- last_feature->next = new_feature;
- last_feature = new_feature;
- }
-
- /* stop searching known features at first found */
- break;
- } /* for i */
- } /* while sensors_get_all_features */
- } /* while sensors_get_detected_chips */
+ last_feature->next = fl;
+ last_feature = fl;
+ } /* while (subfeature) */
+ } /* while (feature) */
+ } /* while (chip) */
+#endif /* (SENSORS_API_VERSION >= 0x400) && (SENSORS_API_VERSION < 0x500) */
if (first_feature == NULL)
{
sensors_cleanup ();
- syslog (LOG_INFO, MODULE_NAME": lm_sensors reports no features. "
- "Data will not be collected.");
+ INFO ("sensors plugin: lm_sensors reports no "
+ "features. Data will not be collected.");
+ return (-1);
}
-} /* void sensors_load_conf */
-#endif /* if SENSORS_HAVE_READ */
-static void collectd_sensors_init (void)
-{
- return;
-}
+ return (0);
+} /* int sensors_load_conf */
-static void sensors_shutdown (void)
+static int sensors_shutdown (void)
{
-#if SENSORS_HAVE_READ
sensors_free_features ();
-#endif /* if SENSORS_HAVE_READ */
-
ignorelist_free (sensor_list);
-}
-static void sensors_voltage_write (char *host, char *inst, char *val)
+ return (0);
+} /* int sensors_shutdown */
+
+static void sensors_submit (const char *plugin_instance,
+ const char *type, const char *type_instance,
+ double val)
{
- char file[BUFSIZE];
+ char match_key[1024];
int status;
- /* skip ignored in our config */
- if (ignorelist_match (sensor_list, inst))
- return;
+ value_t values[1];
+ value_list_t vl = VALUE_LIST_INIT;
- /* extended sensor naming */
- if(sensor_extended_naming)
- status = snprintf (file, BUFSIZE, extended_filename_format, inst);
- else
- status = snprintf (file, BUFSIZE, old_filename_format, inst);
-
- if ((status < 1) || (status >= BUFSIZE))
+ status = snprintf (match_key, sizeof (match_key), "%s/%s-%s",
+ plugin_instance, type, type_instance);
+ if (status < 1)
return;
+ match_key[sizeof (match_key) - 1] = '\0';
- rrd_update_file (host, file, val, sensor_voltage_ds_def, sensor_voltage_ds_num);
-}
+ if (sensor_list != NULL)
+ {
+ DEBUG ("sensors plugin: Checking ignorelist for `%s'", match_key);
+ if (ignorelist_match (sensor_list, match_key))
+ return;
+ }
-static void sensors_write (char *host, char *inst, char *val)
-{
- char file[BUFSIZE];
- int status;
+ values[0].gauge = val;
- /* skip ignored in our config */
- if (ignorelist_match (sensor_list, inst))
- return;
+ vl.values = values;
+ vl.values_len = 1;
+ vl.time = time (NULL);
- /* extended sensor naming */
- if (sensor_extended_naming)
- status = snprintf (file, BUFSIZE, extended_filename_format, inst);
- else
- status = snprintf (file, BUFSIZE, old_filename_format, inst);
-
- if ((status < 1) || (status >= BUFSIZE))
- return;
+ strncpy (vl.host, hostname_g, sizeof (vl.host));
+ vl.host[sizeof (vl.host) - 1] = '\0';
+ strncpy (vl.plugin, "sensors", sizeof (vl.plugin));
+ vl.plugin[sizeof (vl.plugin) - 1] = '\0';
+ strncpy (vl.plugin_instance, plugin_instance,
+ sizeof (vl.plugin_instance));
+ vl.plugin_instance[sizeof (vl.plugin_instance) - 1] = '\0';
+ strncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
+ vl.type_instance[sizeof (vl.type_instance) - 1] = '\0';
- rrd_update_file (host, file, val, ds_def, ds_num);
-}
+ plugin_dispatch_values (type, &vl);
+} /* void sensors_submit */
-#if SENSORS_HAVE_READ
-static void sensors_submit (const char *feat_name,
- const char *chip_prefix, double value, int type)
+static int sensors_read (void)
{
- char buf[BUFSIZE];
- char inst[BUFSIZE];
-
- if (snprintf (inst, BUFSIZE, "%s-%s", chip_prefix, feat_name)
- >= BUFSIZE)
- return;
+ featurelist_t *fl;
- /* skip ignored in our config */
- if (ignorelist_match (sensor_list, inst))
- return;
-
- if (snprintf (buf, BUFSIZE, "%u:%.3f", (unsigned int) curtime,
- value) >= BUFSIZE)
- return;
+ if (sensors_load_conf () != 0)
+ return (-1);
- if (type == SENSOR_TYPE_VOLTAGE)
+#if SENSORS_API_VERSION < 0x400
+ for (fl = first_feature; fl != NULL; fl = fl->next)
{
- DBG ("%s: %s/%s, %s", MODULE_NAME_VOLTAGE,
- sensor_type_prefix[type], inst, buf);
- plugin_submit (MODULE_NAME_VOLTAGE, inst, buf);
- }
- else
- {
- DBG ("%s: %s/%s, %s", MODULE_NAME,
- sensor_type_prefix[type], inst, buf);
- plugin_submit (MODULE_NAME, inst, buf);
- }
-}
+ double value;
+ int status;
+ char plugin_instance[DATA_MAX_NAME_LEN];
+ char type_instance[DATA_MAX_NAME_LEN];
+
+ status = sensors_get_feature (*fl->chip,
+ fl->data->number, &value);
+ if (status < 0)
+ continue;
-static void sensors_read (void)
-{
- featurelist_t *feature;
- double value;
- char chip_fullprefix[BUFSIZE];
+ status = sensors_snprintf_chip_name (plugin_instance,
+ sizeof (plugin_instance), fl->chip);
+ if (status < 0)
+ continue;
+ plugin_instance[sizeof (plugin_instance) - 1] = '\0';
+
+ strncpy (type_instance, fl->data->name,
+ sizeof (type_instance));
+ type_instance[sizeof (type_instance) - 1] = '\0';
- sensors_load_conf ();
+ sensors_submit (plugin_instance,
+ sensor_type_name_map[fl->type],
+ type_instance,
+ value);
+ } /* for fl = first_feature .. NULL */
+/* #endif SENSORS_API_VERSION < 0x400 */
- for (feature = first_feature; feature != NULL; feature = feature->next)
+#elif (SENSORS_API_VERSION >= 0x400) && (SENSORS_API_VERSION < 0x500)
+ for (fl = first_feature; fl != NULL; fl = fl->next)
{
- if (sensors_get_feature (*feature->chip, feature->data->number, &value) < 0)
+ double value;
+ int status;
+ char plugin_instance[DATA_MAX_NAME_LEN];
+ char type_instance[DATA_MAX_NAME_LEN];
+ const char *type;
+
+ status = sensors_get_value (fl->chip,
+ fl->subfeature->number, &value);
+ if (status < 0)
continue;
- if (sensor_extended_naming)
- {
- /* full chip name logic borrowed from lm_sensors */
- if (feature->chip->bus == SENSORS_CHIP_NAME_BUS_ISA)
- {
- if (snprintf (chip_fullprefix, BUFSIZE, "%s-isa-%04x/%s",
- feature->chip->prefix,
- feature->chip->addr,
- sensor_type_prefix[feature->type])
- >= BUFSIZE)
- continue;
- }
- else if (feature->chip->bus == SENSORS_CHIP_NAME_BUS_DUMMY)
- {
- if (snprintf (chip_fullprefix, BUFSIZE, "%s-%s-%04x/%s",
- feature->chip->prefix,
- feature->chip->busname,
- feature->chip->addr,
- sensor_type_prefix[feature->type])
- >= BUFSIZE)
- continue;
- }
- else
- {
- if (snprintf (chip_fullprefix, BUFSIZE, "%s-i2c-%d-%02x/%s",
- feature->chip->prefix,
- feature->chip->bus,
- feature->chip->addr,
- sensor_type_prefix[feature->type])
- >= BUFSIZE)
- continue;
- }
-
- sensors_submit (feature->data->name,
- chip_fullprefix,
- value, feature->type);
- }
+ status = sensors_snprintf_chip_name (plugin_instance,
+ sizeof (plugin_instance), fl->chip);
+ if (status < 0)
+ continue;
+ plugin_instance[sizeof (plugin_instance) - 1] = '\0';
+
+ strncpy (type_instance, fl->feature->name,
+ sizeof (type_instance));
+ type_instance[sizeof (type_instance) - 1] = '\0';
+
+ if (fl->feature->type == SENSORS_FEATURE_IN)
+ type = "voltage";
+ else if (fl->feature->type
+ == SENSORS_FEATURE_FAN)
+ type = "fanspeed";
+ else if (fl->feature->type
+ == SENSORS_FEATURE_TEMP)
+ type = "input";
else
- {
- sensors_submit (feature->data->name,
- feature->chip->prefix,
- value, feature->type);
- }
- } /* for feature = first_feature .. NULL */
-} /* void sensors_read */
-#else
-# define sensors_read NULL
-#endif /* SENSORS_HAVE_READ */
+ continue;
+
+ sensors_submit (plugin_instance, type, type_instance, value);
+ } /* for fl = first_feature .. NULL */
+#endif /* (SENSORS_API_VERSION >= 0x400) && (SENSORS_API_VERSION < 0x500) */
+
+ return (0);
+} /* int sensors_read */
void module_register (void)
{
- plugin_register (MODULE_NAME, collectd_sensors_init, sensors_read, sensors_write);
- plugin_register (MODULE_NAME_VOLTAGE, NULL, NULL, sensors_voltage_write);
- plugin_register_shutdown (MODULE_NAME, sensors_shutdown);
- cf_register (MODULE_NAME, sensors_config, config_keys, config_keys_num);
-}
-
-#undef BUFSIZE
-#undef MODULE_NAME
+ plugin_register_config ("sensors", sensors_config,
+ config_keys, config_keys_num);
+ plugin_register_read ("sensors", sensors_read);
+ plugin_register_shutdown ("sensors", sensors_shutdown);
+} /* void module_register */
projects / collectd.git / blobdiff