enable to remove SNMP timer (which consumne several cycles even when it's not necessary). snmp_agent.txt tell to call snmp_inc_sysuptime() each 10ms (but, it's intrusive if you use sys_timeout feature). Now, you can decide to call snmp_add_sysuptime(100) each 1000ms (which is bigger "step", but call to a lower frequency). Or, you can decide to not call snmp_inc_sysuptime() or snmp_add_sysuptime(), and to define the SNMP_GET_SYSUPTIME(sysuptime) macro. This one is undefined by default in mib2.c. SNMP_GET_SYSUPTIME is called inside snmp_get_sysuptime(u32_t *value), and enable to change "sysuptime" value only when it's queried (any direct call to "sysuptime" is changed by a call to snmp_get_sysuptime).

CHANGELOG

@@ -19,6 +19,18 @@ HISTORY
 
   ++ New features:
 
+  2007-09-10 Frédéric Bernon
+  * snmp.h, mib2.c: enable to remove SNMP timer (which consumne several cycles
+    even when it's not necessary). snmp_agent.txt tell to call snmp_inc_sysuptime()
+    each 10ms (but, it's intrusive if you use sys_timeout feature). Now, you can
+    decide to call snmp_add_sysuptime(100) each 1000ms (which is bigger "step", but
+    call to a lower frequency). Or, you can decide to not call snmp_inc_sysuptime()
+    or snmp_add_sysuptime(), and to define the SNMP_GET_SYSUPTIME(sysuptime) macro.
+    This one is undefined by default in mib2.c. SNMP_GET_SYSUPTIME is called inside
+    snmp_get_sysuptime(u32_t *value), and enable to change "sysuptime" value only
+    when it's queried (any direct call to "sysuptime" is changed by a call to 
+    snmp_get_sysuptime).
+
   2007-09-09 Frédéric Bernon, Bill Florac
   * igmp.h, igmp.c, netif.h, netif.c, ip.c: To enable to have interfaces with IGMP,
     and others without it, there is a new NETIF_FLAG_IGMP flag to set in netif->flags

src/core/snmp/mib2.c

@@ -70,6 +70,10 @@
 #define SNMP_SYSSERVICES ((1 << 6) | (1 << 3) | ((IP_FORWARD) << 2))
 #endif
 
+#ifndef SNMP_GET_SYSUPTIME
+#define SNMP_GET_SYSUPTIME(sysuptime)
+#endif
+
 static void system_get_object_def(u8_t ident_len, s32_t *ident, struct obj_def *od);
 static void system_get_value(struct obj_def *od, u16_t len, void *value);
 static u8_t system_set_test(struct obj_def *od, u16_t len, void *value);
@@ -949,8 +953,14 @@ void snmp_inc_sysuptime(void)
   sysuptime++;
 }
 
+void snmp_add_sysuptime(u32_t value)
+{
+  sysuptime+=value;
+}
+
 void snmp_get_sysuptime(u32_t *value)
 {
+  SNMP_GET_SYSUPTIME(sysuptime);
   *value = sysuptime;
 }
 
@@ -2193,8 +2203,7 @@ system_get_value(struct obj_def *od, u16_t len, void *value)
       break;
     case 3: /* sysUpTime */
       {
-        u32_t *uint_ptr = value;
-        *uint_ptr = sysuptime;
+        snmp_get_sysuptime(value);
       }
       break;
     case 4: /* sysContact */

src/include/lwip/snmp.h

@@ -81,8 +81,12 @@ enum snmp_ifType {
 
 #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
 
+/** SNMP "sysuptime" Interval */
+#define SNMP_SYSUPTIME_INTERVAL 10
+
 /** fixed maximum length for object identifier type */
 #define LWIP_SNMP_OBJ_ID_LEN 32
+
 /** internal object identifier representation */
 struct snmp_obj_id
 {
@@ -95,6 +99,7 @@ void snmp_set_sysdesr(u8_t* str, u8_t* len);
 void snmp_set_sysobjid(struct snmp_obj_id *oid);
 void snmp_get_sysobjid_ptr(struct snmp_obj_id **oid);
 void snmp_inc_sysuptime(void);
+void snmp_add_sysuptime(u32_t value);
 void snmp_get_sysuptime(u32_t *value);
 void snmp_set_syscontact(u8_t *ocstr, u8_t *ocstrlen);
 void snmp_set_sysname(u8_t *ocstr, u8_t *ocstrlen);
@@ -227,6 +232,7 @@ void snmp_get_snmpenableauthentraps(u8_t *value);
 #define snmp_set_sysobjid(oid);
 #define snmp_get_sysobjid_ptr(oid)
 #define snmp_inc_sysuptime()
+#define snmp_add_sysuptime(value)
 #define snmp_get_sysuptime(value)
 #define snmp_set_syscontact(ocstr, ocstrlen);
 #define snmp_set_sysname(ocstr, ocstrlen);