X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Futils%2Fproto.c;h=f8265d6861da71335da53a88d3c932b713c718e6;hp=51c2ed8c45361f4625c4e7dc6d956594d7a96a7e;hb=c603d51e4ad3adea8d3f3afc8b796e49c180030b;hpb=57331451a2eb8cbcd812e7428ab1ded6d312365f

diff --git a/src/utils/proto.c b/src/utils/proto.c
index 51c2ed8..f8265d6 100644
--- a/src/utils/proto.c
+++ b/src/utils/proto.c
@@ -30,6 +30,7 @@
 #endif
 
 #include "core/data.h"
+#include "core/store.h"
 #include "core/time.h"
 #include "utils/error.h"
 #include "utils/proto.h"
@@ -40,6 +41,7 @@
 #include <arpa/inet.h>
 #include <limits.h>
 
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -49,63 +51,220 @@
  * private helper functions
  */
 
+/* swap endianess of the specified 64-bit value */
+static uint64_t
+endian_swap64(uint64_t v)
+{
+	return
+		  (((v & 0xff00000000000000LL) >> 56) & 0x00000000000000ffLL)
+		| (((v & 0x00ff000000000000LL) >> 40) & 0x000000000000ff00LL)
+		| (((v & 0x0000ff0000000000LL) >> 24) & 0x0000000000ff0000LL)
+		| (((v & 0x000000ff00000000LL) >> 8)  & 0x00000000ff000000LL)
+		| (((v & 0x00000000ff000000LL) << 8)  & 0x000000ff00000000LL)
+		| (((v & 0x0000000000ff0000LL) << 24) & 0x0000ff0000000000LL)
+		| (((v & 0x000000000000ff00LL) << 40) & 0x00ff000000000000LL)
+		| (((v & 0x00000000000000ffLL) << 56) & 0xff00000000000000LL);
+} /* endian_swap64 */
+
+static unsigned char *
+memdup(const unsigned char *d, size_t length)
+{
+	unsigned char *v = malloc(length);
+	if (! v)
+		return NULL;
+	memcpy(v, d, length);
+	return v;
+} /* memdup */
+
 /* In case there's not enough buffer space, the marshal functions have to
  * return the number of bytes that would have been written if enough space had
  * been available. */
 
 static ssize_t
-marshal_int(char *buf, size_t buf_len, int64_t v)
+marshal_bool(char *buf, size_t buf_len, bool v)
+{
+	uint8_t t;
+	if (buf_len >= sizeof(t)) {
+		t = v ? 1 : 0;
+		memcpy(buf, &t, sizeof(t));
+	}
+	return sizeof(t);
+} /* marshal_bool */
+
+static ssize_t
+unmarshal_bool(const char *buf, size_t len, bool *v)
+{
+	uint8_t t;
+	if (len < sizeof(t))
+		return -1;
+	if (v) {
+		memcpy(&t, buf, sizeof(t));
+		*v = t != 0;
+	}
+	return sizeof(t);
+} /* unmarshal_bool */
+
+static ssize_t
+marshal_int64(char *buf, size_t buf_len, int64_t v)
 {
 	if (buf_len >= sizeof(v)) {
 #if __BYTE_ORDER != __BIG_ENDIAN
-		v = (((int64_t)ntohl((int32_t)v)) << 32)
-			+ ((int64_t)ntohl((int32_t)(v >> 32)));
+		v = endian_swap64(v);
 #endif
 		memcpy(buf, &v, sizeof(v));
 	}
 	return sizeof(v);
-} /* marshal_int */
+} /* marshal_int64 */
+
+static ssize_t
+unmarshal_int64(const char *buf, size_t len, int64_t *v)
+{
+	if (len < sizeof(*v))
+		return -1;
+	if (v) {
+		memcpy(v, buf, sizeof(*v));
+#if __BYTE_ORDER != __BIG_ENDIAN
+		*v = endian_swap64(*v);
+#endif
+	}
+	return sizeof(*v);
+} /* unmarshal_int64 */
 
 static ssize_t
 marshal_double(char *buf, size_t buf_len, double v)
 {
 	uint64_t t = 0;
 	assert(sizeof(v) == sizeof(t));
-	memcpy(&t, &v, sizeof(v));
+	if (buf_len >= sizeof(t)) {
+		memcpy(&t, &v, sizeof(v));
 #if IEEE754_DOUBLE_BYTE_ORDER != IEEE754_DOUBLE_BIG_ENDIAN
-	t = (((int64_t)ntohl((int32_t)t)) << 32)
-		+ ((int64_t)ntohl((int32_t)(t >> 32)));
+		t = endian_swap64(t);
 #endif
-	if (buf_len >= sizeof(t))
 		memcpy(buf, &t, sizeof(t));
+	}
 	return sizeof(t);
 } /* marshal_double */
 
+static ssize_t
+unmarshal_double(const char *buf, size_t len, double *v)
+{
+	uint64_t t;
+	assert(sizeof(*v) == sizeof(t));
+	if (len < sizeof(*v))
+		return -1;
+	if (v) {
+		memcpy(&t, buf, sizeof(t));
+#if IEEE754_DOUBLE_BYTE_ORDER != IEEE754_DOUBLE_BIG_ENDIAN
+		t = endian_swap64(t);
+#endif
+		memcpy(v, &t, sizeof(t));
+	}
+	return sizeof(*v);
+} /* unmarshal_double */
+
 static ssize_t
 marshal_datetime(char *buf, size_t buf_len, sdb_time_t v)
 {
-	return marshal_int(buf, buf_len, (int64_t)v);
+	return marshal_int64(buf, buf_len, (int64_t)v);
 } /* marshal_datetime */
 
+static ssize_t
+unmarshal_datetime(const char *buf, size_t len, sdb_time_t *v)
+{
+	return unmarshal_int64(buf, len, (int64_t *)v);
+} /* unmarshal_datetime */
+
 static ssize_t
 marshal_binary(char *buf, size_t buf_len, size_t len, const unsigned char *v)
 {
-	uint32_t tmp = htonl((uint32_t)len);
-	if (buf_len >= len) {
+	uint32_t tmp;
+	if (buf_len >= sizeof(tmp) + len) {
+		tmp = htonl((uint32_t)len);
 		memcpy(buf, &tmp, sizeof(tmp));
 		memcpy(buf + sizeof(tmp), v, len);
 	}
 	return sizeof(tmp) + len;
 } /* marshal_binary */
 
+static ssize_t
+unmarshal_binary(const char *buf, size_t len,
+		size_t *v_len, const unsigned char **v)
+{
+	uint32_t l;
+	ssize_t n;
+
+	if ((n = sdb_proto_unmarshal_int32(buf, len, &l)) < 0)
+		return -1;
+	buf += n; len -= n;
+	if (len < (size_t)l)
+		return -1;
+
+	if (v_len)
+		*v_len = (size_t)l;
+	if (v && (l > 0))
+		*v = (const unsigned char *)buf;
+	else if (v)
+		*v = NULL;
+	return sizeof(l) + (ssize_t)l;
+} /* unmarshal_binary */
+
 static ssize_t
 marshal_string(char *buf, size_t buf_len, const char *v)
 {
 	/* The actual string including the terminating null byte. */
-	return marshal_binary(buf, buf_len,
-			strlen(v) + 1, (const unsigned char *)v);
+	size_t len = strlen(v) + 1;
+	if (buf_len >= len)
+		memcpy(buf, v, len);
+	return len;
 } /* marshal_string */
 
+static ssize_t
+unmarshal_string(const char *buf, size_t len, const char **v)
+{
+	size_t l = 0;
+
+	for (l = 0; l < len; ++l)
+		if (buf[l] == '\0')
+			break;
+	if (l == len)
+		return -1;
+	if (v)
+		*v = buf;
+	return l + 1;
+} /* unmarshal_string */
+
+#define OBJ_HEADER_LEN (sizeof(uint32_t) + sizeof(sdb_time_t))
+static ssize_t
+marshal_obj_header(char *buf, size_t buf_len,
+		int type, sdb_time_t last_update)
+{
+	ssize_t n;
+
+	if (buf_len < OBJ_HEADER_LEN)
+		return OBJ_HEADER_LEN;
+
+	n = sdb_proto_marshal_int32(buf, buf_len, (uint32_t)type);
+	buf += n; buf_len -= n;
+	marshal_datetime(buf, buf_len, last_update);
+	return OBJ_HEADER_LEN;
+} /* marshal_obj_header */
+
+static ssize_t
+unmarshal_obj_header(const char *buf, size_t len,
+		int *type, sdb_time_t *last_update)
+{
+	ssize_t n;
+
+	if (len < OBJ_HEADER_LEN)
+		return -1;
+
+	n = sdb_proto_unmarshal_int32(buf, len, (uint32_t *)type);
+	buf += n; len -= n;
+	if (unmarshal_datetime(buf, len, last_update) < 0)
+		return -1;
+	return OBJ_HEADER_LEN;
+} /* unmarshal_obj_header */
+
 /*
  * public API
  */
@@ -133,7 +292,17 @@ sdb_proto_marshal(char *buf, size_t buf_len, uint32_t code,
 } /* sdb_proto_marshal */
 
 ssize_t
-sdb_proto_marshal_data(char *buf, size_t buf_len, sdb_data_t *datum)
+sdb_proto_marshal_int32(char *buf, size_t buf_len, uint32_t v)
+{
+	if (buf_len >= sizeof(v)) {
+		v = htonl(v);
+		memcpy(buf, &v, sizeof(v));
+	}
+	return sizeof(v);
+} /* sdb_proto_marshal_int32 */
+
+ssize_t
+sdb_proto_marshal_data(char *buf, size_t buf_len, const sdb_data_t *datum)
 {
 	ssize_t len = 0, n = 0;
 	uint32_t tmp;
@@ -153,8 +322,10 @@ sdb_proto_marshal_data(char *buf, size_t buf_len, sdb_data_t *datum)
 	if (datum->type == SDB_TYPE_NULL)
 		return len;
 
-	if (datum->type == SDB_TYPE_INTEGER)
-		n = marshal_int(buf, buf_len, datum->data.integer);
+	if (datum->type == SDB_TYPE_BOOLEAN)
+		n = marshal_bool(buf, buf_len, datum->data.boolean);
+	else if (datum->type == SDB_TYPE_INTEGER)
+		n = marshal_int64(buf, buf_len, datum->data.integer);
 	else if (datum->type == SDB_TYPE_DECIMAL)
 		n = marshal_double(buf, buf_len, datum->data.decimal);
 	else if (datum->type == SDB_TYPE_STRING)
@@ -190,9 +361,13 @@ sdb_proto_marshal_data(char *buf, size_t buf_len, sdb_data_t *datum)
 
 	type = datum->type & 0xff;
 	for (i = 0; i < datum->data.array.length; ++i) {
-		if (type == SDB_TYPE_INTEGER) {
+		if (type == SDB_TYPE_BOOLEAN) {
+			bool *v = datum->data.array.values;
+			n = marshal_bool(buf, buf_len, v[i]);
+		}
+		else if (type == SDB_TYPE_INTEGER) {
 			int64_t *v = datum->data.array.values;
-			n = marshal_int(buf, buf_len, v[i]);
+			n = marshal_int64(buf, buf_len, v[i]);
 		}
 		else if (type == SDB_TYPE_DECIMAL) {
 			double *v = datum->data.array.values;
@@ -238,37 +413,420 @@ sdb_proto_marshal_data(char *buf, size_t buf_len, sdb_data_t *datum)
 	return len;
 } /* sdb_proto_marshal_data */
 
-int
+ssize_t
+sdb_proto_marshal_host(char *buf, size_t buf_len,
+		const sdb_proto_host_t *host)
+{
+	size_t len;
+	ssize_t n;
+
+	if ((! host) || (! host->name))
+		return -1;
+
+	len = OBJ_HEADER_LEN + strlen(host->name) + 1;
+	if (buf_len < len)
+		return len;
+
+	n = marshal_obj_header(buf, buf_len, SDB_HOST, host->last_update);
+	buf += n; buf_len -= n;
+	marshal_string(buf, buf_len, host->name);
+	return len;
+} /* sdb_proto_marshal_host */
+
+ssize_t
+sdb_proto_marshal_service(char *buf, size_t buf_len,
+		const sdb_proto_service_t *svc)
+{
+	size_t len;
+	ssize_t n;
+
+	if ((! svc) || (! svc->hostname) || (! svc->name))
+		return -1;
+
+	len = OBJ_HEADER_LEN + strlen(svc->hostname) + strlen(svc->name) + 2;
+	if (buf_len < len)
+		return len;
+
+	n = marshal_obj_header(buf, buf_len, SDB_SERVICE, svc->last_update);
+	buf += n; buf_len -= n;
+	n = marshal_string(buf, buf_len, svc->hostname);
+	buf += n; buf_len -= n;
+	marshal_string(buf, buf_len, svc->name);
+	return len;
+} /* sdb_proto_marshal_service */
+
+ssize_t
+sdb_proto_marshal_metric(char *buf, size_t buf_len,
+		const sdb_proto_metric_t *metric)
+{
+	size_t len;
+	ssize_t n;
+
+	if ((! metric) || (! metric->hostname) || (! metric->name))
+		return -1;
+
+	len = OBJ_HEADER_LEN + strlen(metric->hostname) + strlen(metric->name) + 2;
+	if (metric->store_type && metric->store_id)
+		len += strlen(metric->store_type) + strlen(metric->store_id) + 2;
+	if (buf_len < len)
+		return len;
+
+	n = marshal_obj_header(buf, buf_len, SDB_METRIC, metric->last_update);
+	buf += n; buf_len -= n;
+	n = marshal_string(buf, buf_len, metric->hostname);
+	buf += n; buf_len -= n;
+	n = marshal_string(buf, buf_len, metric->name);
+	buf += n; buf_len -= n;
+	if (metric->store_type && metric->store_id) {
+		n = marshal_string(buf, buf_len, metric->store_type);
+		buf += n; buf_len -= n;
+		marshal_string(buf, buf_len, metric->store_id);
+	}
+	return len;
+} /* sdb_proto_marshal_metric */
+
+ssize_t
+sdb_proto_marshal_attribute(char *buf, size_t buf_len,
+		const sdb_proto_attribute_t *attr)
+{
+	size_t len;
+	ssize_t n;
+
+	if ((! attr) || (! attr->parent) || (! attr->key)
+			|| ((attr->parent_type != SDB_HOST) && (! attr->hostname))
+			|| ((attr->parent_type != SDB_HOST)
+				&& (attr->parent_type != SDB_SERVICE)
+				&& (attr->parent_type != SDB_METRIC)))
+		return -1;
+
+	n = sdb_proto_marshal_data(NULL, 0, &attr->value);
+	if (n < 0)
+		return -1;
+
+	len = OBJ_HEADER_LEN
+		+ strlen(attr->parent) + strlen(attr->key) + 2 + (size_t)n;
+	if (attr->parent_type != SDB_HOST)
+		len += strlen(attr->hostname) + 1;
+	if (buf_len < len)
+		return len;
+
+	n = marshal_obj_header(buf, buf_len,
+			attr->parent_type | SDB_ATTRIBUTE, attr->last_update);
+	buf += n; buf_len -= n;
+	if (attr->parent_type != SDB_HOST) {
+		n = marshal_string(buf, buf_len, attr->hostname);
+		buf += n; buf_len -= n;
+	}
+	n = marshal_string(buf, buf_len, attr->parent);
+	buf += n; buf_len -= n;
+	n = marshal_string(buf, buf_len, attr->key);
+	buf += n; buf_len -= n;
+	sdb_proto_marshal_data(buf, buf_len, &attr->value);
+	return len;
+} /* sdb_proto_marshal_attribute */
+
+ssize_t
 sdb_proto_unmarshal_header(const char *buf, size_t buf_len,
 		uint32_t *code, uint32_t *msg_len)
 {
 	uint32_t tmp;
+	ssize_t n;
 
 	if (buf_len < 2 * sizeof(uint32_t))
 		return -1;
 
-	tmp = sdb_proto_unmarshal_int(buf, buf_len);
+	n = sdb_proto_unmarshal_int32(buf, buf_len, &tmp);
 	if (code)
 		*code = tmp;
-	tmp = sdb_proto_unmarshal_int(buf + sizeof(uint32_t),
-			buf_len - sizeof(uint32_t));
+	buf += n; buf_len -= n;
+	sdb_proto_unmarshal_int32(buf, buf_len, &tmp);
 	if (msg_len)
 		*msg_len = tmp;
-	return 0;
+	return 2 * sizeof(uint32_t);
 } /* sdb_proto_unmarshal_header */
 
-uint32_t
-sdb_proto_unmarshal_int(const char *buf, size_t buf_len)
+ssize_t
+sdb_proto_unmarshal_int32(const char *buf, size_t buf_len, uint32_t *v)
 {
 	uint32_t n;
 
 	/* not enough data to read */
 	if (buf_len < sizeof(n))
-		return UINT32_MAX;
+		return -1;
 
 	memcpy(&n, buf, sizeof(n));
-	return ntohl(n);
-} /* sdb_proto_unmarshal_int */
+	if (v)
+		*v = ntohl(n);
+	return sizeof(n);
+} /* sdb_proto_unmarshal_int32 */
+
+ssize_t
+sdb_proto_unmarshal_data(const char *buf, size_t len, sdb_data_t *datum)
+{
+	sdb_data_t d = SDB_DATA_INIT;
+	ssize_t l = 0, n;
+	uint32_t tmp;
+	size_t i;
+
+	if ((n = sdb_proto_unmarshal_int32(buf, len, &tmp)) < 0)
+		return -1;
+	d.type = (int)tmp;
+	if (d.type == SDB_TYPE_NULL)
+		return sizeof(tmp);
+	buf += n; len -= n; l += n;
+
+/* Don't populate 'd' if 'datum' is NULL. */
+#define D(field) (datum ? &d.data.field : NULL)
+	if (d.type == SDB_TYPE_BOOLEAN)
+		n = unmarshal_bool(buf, len, D(boolean));
+	else if (d.type == SDB_TYPE_INTEGER)
+		n = unmarshal_int64(buf, len, D(integer));
+	else if (d.type == SDB_TYPE_DECIMAL)
+		n = unmarshal_double(buf, len, D(decimal));
+	else if (d.type == SDB_TYPE_STRING) {
+		const char *str = NULL;
+		n = unmarshal_string(buf, len, &str);
+		if ((n > 0) && datum)
+			if (! (d.data.string = strdup(str)))
+				n = -1;
+	}
+	else if (d.type == SDB_TYPE_DATETIME)
+		n = unmarshal_datetime(buf, len, D(datetime));
+	else if (d.type == SDB_TYPE_BINARY) {
+		const unsigned char *data = NULL;
+		n = unmarshal_binary(buf, len, D(binary.length), &data);
+		if ((n > 0) && datum)
+			if (! (d.data.binary.datum = memdup(data, d.data.binary.length)))
+				n = -1;
+	}
+	else if (d.type == SDB_TYPE_REGEX) {
+		if (datum) {
+			const char *str = NULL;
+			n = unmarshal_string(buf, len, &str);
+			if (sdb_data_parse(str, SDB_TYPE_REGEX, &d))
+				n = -1;
+		}
+		else
+			n = unmarshal_string(buf, len, NULL);
+	}
+	else
+		n = 0;
+#undef D
+
+	if (n < 0)
+		return n;
+	else if (n > 0) {
+		if (datum)
+			*datum = d;
+		return l + n;
+	}
+
+	if (! (d.type & SDB_TYPE_ARRAY)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* arrays */
+	if ((n = sdb_proto_unmarshal_int32(buf, len, &tmp)) < 0)
+		return -1;
+	buf += n; len -= n; l += n;
+	d.data.array.length = (size_t)tmp;
+
+#define V(field) (datum ? &v[i]field : NULL)
+	if (datum)
+		d.data.array.values = calloc(d.data.array.length,
+				sdb_data_sizeof(d.type & 0xff));
+	for (i = 0; i < d.data.array.length; ++i) {
+		if ((d.type & 0xff) == SDB_TYPE_BOOLEAN) {
+			bool *v = d.data.array.values;
+			n = unmarshal_bool(buf, len, V());
+		}
+		else if ((d.type & 0xff) == SDB_TYPE_INTEGER) {
+			int64_t *v = d.data.array.values;
+			n = unmarshal_int64(buf, len, V());
+		}
+		else if ((d.type & 0xff) == SDB_TYPE_DECIMAL) {
+			double *v = d.data.array.values;
+			n = unmarshal_double(buf, len, V());
+		}
+		else if ((d.type & 0xff) == SDB_TYPE_STRING) {
+			char **v = d.data.array.values;
+			const char *str = NULL;
+			n = unmarshal_string(buf, len, &str);
+			if ((n > 0) && datum)
+				if (! (v[i] = strdup(str)))
+					n = -1;
+		}
+		else if ((d.type & 0xff) == SDB_TYPE_DATETIME) {
+			sdb_time_t *v = d.data.array.values;
+			n = unmarshal_datetime(buf, len, V());
+		}
+		else if ((d.type & 0xff) == SDB_TYPE_BINARY) {
+			struct {
+				size_t length;
+				unsigned char *datum;
+			} *v = d.data.array.values;
+			const unsigned char *data = NULL;
+
+			n = unmarshal_binary(buf, len, V(.length), &data);
+			if ((n > 0) && datum)
+				if (! (v[i].datum = memdup(data, v[i].length)))
+					n = -1;
+		}
+		else if ((d.type & 0xff) == SDB_TYPE_REGEX) {
+			struct {
+				char *raw;
+				regex_t regex;
+			} *v = d.data.array.values;
+			if (datum) {
+				sdb_data_t t = SDB_DATA_INIT;
+				const char *str = NULL;
+				n = unmarshal_string(buf, len, &str);
+				if (! sdb_data_parse(str, SDB_TYPE_REGEX, &t)) {
+					v[i].raw = t.data.re.raw;
+					v[i].regex = t.data.re.regex;
+				}
+				else
+					n = -1;
+			}
+			else
+				n = unmarshal_string(buf, len, NULL);
+		}
+		else {
+			if (datum)
+				sdb_data_free_datum(&d);
+			errno = EINVAL;
+			return -1;
+		}
+
+		if (n < 0) {
+			if (datum)
+				sdb_data_free_datum(&d);
+			return -1;
+		}
+		buf += n; len -= n; l += n;
+	}
+#undef V
+
+	if (datum)
+		*datum = d;
+	return l;
+} /* sdb_proto_unmarshal_data */
+
+ssize_t
+sdb_proto_unmarshal_host(const char *buf, size_t len,
+		sdb_proto_host_t *host)
+{
+	int type = 0;
+	ssize_t l = 0, n;
+
+	if ((n = unmarshal_obj_header(buf, len,
+					&type, host ? &host->last_update : NULL)) < 0)
+		return n;
+	if (type != SDB_HOST)
+		return -1;
+	buf += n; len -= n; l += n;
+	if ((n = unmarshal_string(buf, len, host ? &host->name : NULL)) < 0)
+		return n;
+	return l + n;
+} /* sdb_proto_unmarshal_host */
+
+ssize_t
+sdb_proto_unmarshal_service(const char *buf, size_t len,
+		sdb_proto_service_t *svc)
+{
+	int type = 0;
+	ssize_t l = 0, n;
+
+	if ((n = unmarshal_obj_header(buf, len,
+					&type, svc ? &svc->last_update : NULL)) < 0)
+		return n;
+	if (type != SDB_SERVICE)
+		return -1;
+	buf += n; len -= n; l += n;
+	if ((n = unmarshal_string(buf, len, svc ? &svc->hostname : NULL)) < 0)
+		return n;
+	buf += n; len -= n; l += n;
+	if ((n = unmarshal_string(buf, len, svc ? &svc->name : NULL)) < 0)
+		return n;
+	return l + n;
+} /* sdb_proto_unmarshal_service */
+
+ssize_t
+sdb_proto_unmarshal_metric(const char *buf, size_t len,
+		sdb_proto_metric_t *metric)
+{
+	int type = 0;
+	ssize_t l = 0, n;
+
+	if ((n = unmarshal_obj_header(buf, len,
+					&type, metric ? &metric->last_update : NULL)) < 0)
+		return n;
+	if (type != SDB_METRIC)
+		return -1;
+	buf += n; len -= n; l += n;
+	if ((n = unmarshal_string(buf, len,
+					metric ? &metric->hostname : NULL)) < 0)
+		return n;
+	buf += n; len -= n; l += n;
+	if ((n = unmarshal_string(buf, len, metric ? &metric->name : NULL)) < 0)
+		return n;
+	if (len > (size_t)n) {
+		buf += n; len -= n; l += n;
+		if ((n = unmarshal_string(buf, len,
+						metric ? &metric->store_type : NULL)) < 0)
+			return n;
+		buf += n; len -= n; l += n;
+		if ((n = unmarshal_string(buf, len,
+						metric ? &metric->store_id : NULL)) < 0)
+			return n;
+	}
+	else if (metric) {
+		metric->store_type = NULL;
+		metric->store_id = NULL;
+	}
+	return l + n;
+} /* sdb_proto_unmarshal_metric */
+
+ssize_t
+sdb_proto_unmarshal_attribute(const char *buf, size_t len,
+		sdb_proto_attribute_t *attr)
+{
+	int parent_type, type = 0;
+	ssize_t l = 0, n;
+
+	if ((n = unmarshal_obj_header(buf, len,
+					&type, attr ? &attr->last_update : NULL)) < 0)
+		return n;
+	buf += n; len -= n; l += n;
+	parent_type = type & 0xf;
+	if (type != (parent_type | SDB_ATTRIBUTE))
+		return -1;
+	if ((parent_type != SDB_HOST) && (parent_type != SDB_SERVICE)
+				&& (parent_type != SDB_METRIC))
+		return -1;
+	if (attr)
+		attr->parent_type = parent_type;
+
+	if (parent_type != SDB_HOST) {
+		if ((n = unmarshal_string(buf, len,
+						attr ? &attr->hostname : NULL)) < 0)
+			return n;
+		buf += n; len -= n; l += n;
+	}
+	else if (attr)
+		attr->hostname = NULL;
+	if ((n = unmarshal_string(buf, len, attr ? &attr->parent : NULL)) < 0)
+		return n;
+	buf += n; len -= n; l += n;
+	if ((n = unmarshal_string(buf, len, attr ? &attr->key : NULL)) < 0)
+		return n;
+	buf += n; len -= n; l += n;
+	if ((n = sdb_proto_unmarshal_data(buf, len,
+					attr ? &attr->value : NULL)) < 0)
+		return n;
+	return l + n;
+} /* sdb_proto_unmarshal_attribute */
 
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