userspace/snmpd: add template for scalar groups

To avoid multiple copies of the same/simillar code template for scalar groups is introduced. File wrsGroupTemplate.h should be included into file defining scalar group. pickinfo and FIELD definition was moved to wrsSnmp.h Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

userspace/snmpd: add template for scalar groups
To avoid multiple copies of the same/simillar code template for scalar groups is introduced. File wrsGroupTemplate.h should be included into file defining scalar group. pickinfo and FIELD definition was moved to wrsSnmp.h Signed-off-by: Adam Wujek <adam.wujek@cern.ch>
e1195ab4 · Adam Wujek · 2fa02f9f · e1195ab4 · e1195ab4 · e1195ab4
Commit e1195ab4 authored Mar 18, 2015 by Adam Wujek 💬
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wrsGroupTemplate.h userspace/snmpd/wrsGroupTemplate.h +61 -0

wrsPpsi.c userspace/snmpd/wrsPpsi.c +0 -7

wrsSnmp.h userspace/snmpd/wrsSnmp.h +11 -0

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--- a/userspace/snmpd/wrsGroupTemplate.h
+++ b/userspace/snmpd/wrsGroupTemplate.h
+static int group_handler(netsnmp_mib_handler          *handler,
+			netsnmp_handler_registration *reginfo,
+			netsnmp_agent_request_info   *reqinfo,
+			netsnmp_request_info         *requests)
+{
+
+	int obj; /* the final index */
+	struct pickinfo *pi;
+	void *ptr;
+	int len;
+
+	/*
+	 * Retrieve information from ppsi itself. But this function
+	 * is called once for every item, so only query the whole set
+	 * once every 2 seconds.
+	 */
+
+
+	GT_DATA_FILL_FUNC();
+	switch (reqinfo->mode) {
+	case MODE_GET:
+		/* "- 2" because last is 0 for all scalars, I suppose */
+		obj = requests->requestvb->name[
+			requests->requestvb->name_length - 2];
+		obj--; /* we are 0-based */
+		if (obj < 0 || obj >= ARRAY_SIZE(GT_PICKINFO)) {
+			snmp_log(LOG_ERR,
+				 "wrong index (%d) in "GT_GROUP_NAME"\n",
+				 obj + 1);
+			return SNMP_ERR_GENERR;
+		}
+		pi = GT_PICKINFO + obj;
+		ptr = (void *)&GT_DATA_STRUCT + pi->offset;
+		len = pi->len;
+		if (len > 8) /* special case for strings */
+			len = strnlen(ptr, len);
+		snmp_set_var_typed_value(requests->requestvb,
+					 pi->type, ptr, len);
+		break;
+	default:
+		snmp_log(LOG_ERR, "unknown mode (%d) in "GT_GROUP_NAME"\n",
+			 reqinfo->mode);
+		return SNMP_ERR_GENERR;
+	}
+	return SNMP_ERR_NOERROR;
+}
+
+/* init function */
+void GT_INIT_FUNC(void)
+{
+	const oid wrsGT_oid[] = { GT_OID };
+	netsnmp_handler_registration *hreg;
+
+	/* do the registration for the scalars/globals */
+	hreg = netsnmp_create_handler_registration(
+		GT_GROUP_NAME, group_handler,
+		wrsGT_oid, OID_LENGTH(wrsGT_oid),
+		HANDLER_CAN_RONLY);
+	netsnmp_register_scalar_group(
+		hreg, 1 /* min */, ARRAY_SIZE(GT_PICKINFO) /* max */);
+}
--- a/userspace/snmpd/wrsPpsi.c
+++ b/userspace/snmpd/wrsPpsi.c
@@ -41,13 +41,6 @@ static struct wrs_shm_head *ppsi_head;
 static struct pp_globals *ppg;
 struct wr_servo_state_t *ppsi_servo;

-#define FIELD(_struct, _type, _field) {			\
-		.type = _type,					\
-		.offset = offsetof(struct _struct, _field),	\
-		.len = sizeof(_struct._field),			\
-		 }
-
-
 /* Our data: globals */
 static struct wrs_p_globals {
 	ClockIdentity gm_id;	/* FIXME: not implemented */

--- a/userspace/snmpd/wrsSnmp.h
+++ b/userspace/snmpd/wrsSnmp.h
@@ -85,4 +85,15 @@ extern void init_wrsDate(void);

 #define WRS_OID 1, 3, 6, 1, 4, 1, 96, 100

+struct pickinfo {
+	/* Following fields are used to format the output */
+	int type; int offset; int len;
+};
+
+#define FIELD(_struct, _type, _field) {			\
+	.type = _type,					\
+	.offset = offsetof(struct _struct, _field),	\
+	.len = sizeof(_struct._field),			\
+	 }
+
 #endif /* WRS_SNMP_H */