MIB-2 object values near to completion, just committing for keeping the flame alive.

doc/snmp_agent.txt

@@ -50,6 +50,20 @@ Running the agent
 The following function calls must be made in your program to
 actually get the SNMP agent running.
 
+Before starting the agent you should supply pointers
+to non-volatile memory for sysContact, sysLocation,
+and snmpEnableAuthenTraps. You can do this by calling
+
+snmp_set_syscontact()
+snmp_set_syslocation()
+snmp_set_snmpenableauthentraps()
+
+Additionally you may want to set
+
+snmp_set_sysdescr()
+snmp_set_sysobjid() (if you have a private MIB)
+snmp_set_sysname()
+
 In the lwIP initialisation sequence call snmp_init() just after
 the call to udp_init().
 
@@ -57,14 +71,6 @@ Exactly every 10 msec the SNMP uptime timestamp must be updated with
 snmp_inc_sysuptime(). You should call this from a timer interrupt
 or a timer signal handler depending on your runtime environment.
 
-You _must_ create the following support functions for non-volatile storage
-since lwIP does not have notion of files or other non-volatile memories.
-
-void snmp_store_syscontact(u8_t* ocstr, u8_t ocstrlen);
-void snmp_store_sysname(u8_t* ocstr, u8_t ocstrlen);
-void snmp_store_syslocation(u8_t* ocstr, u8_t ocstrlen);
-
-
 
 Private MIBs
 ============

src/core/snmp/mib_structs.c

@@ -221,4 +221,26 @@ snmp_search_tree(struct mib_node *node, u8_t ident_len, s32_t *ident, struct obj
   return NULL;
 }
 
+/**
+ * Test object identifier for the iso.org.dod.internet prefix.
+ *
+ * @param ident_len the length of the supplied object identifier
+ * @param ident points to the array of sub identifiers
+ * @return 1 if it matches, 0 otherwise
+ */
+u8_t
+snmp_iso_prefix_tst(u8_t ident_len, s32_t *ident)
+{
+  if ((ident_len > 3) &&
+      (ident[0] == 1) && (ident[1] == 3) &&
+      (ident[2] == 6) && (ident[3] == 1))
+  {
+    return 1;
+  }
+  else
+  {
+    return 0;
+  }
+}
+
 #endif /* LWIP_SNMP */

src/core/snmp/msg_in.c

@@ -46,7 +46,6 @@
 #include "lwip/snmp.h"
 #include "lwip/snmp_asn1.h"
 #include "lwip/snmp_msg.h"
-
 #include "lwip/snmp_structs.h"
 
 #if LWIP_SNMP
@@ -74,9 +73,7 @@ static void snmp_varbind_list_free(struct snmp_varbind_root *root);
 static void snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb);
 static struct snmp_varbind* snmp_varbind_tail_remove(struct snmp_varbind_root *root);
 
-/** @todo: move this to  header */
+
-extern const struct mib_array_node internet;
-extern const struct mib_array_node sys_tem; /* test only */
 
 /**
  * Starts SNMP Agent.
@@ -106,11 +103,81 @@ snmp_init(void)
 }
 
 /**
- *
+ * called for each variable binding (also for the fist one)
  */
 void
-snmp_msg_event(void)
+snmp_msg_event(struct snmp_msg_pstat *msg_ps)
 {
+  struct mib_node *mn;
+  struct obj_def object_def;
+
+  if (msg_ps->state == SNMP_MSG_DEMUX)
+  {
+    if (msg_ps->vb_idx == 0)
+    {
+      msg_ps->vb_ptr = msg_ps->invb.head;
+    }
+    else
+    {
+      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
+      msg_ps->vb_idx += 1;
+    }
+    if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ)
+    { 
+      /** test object identifier for .iso.org.dod.internet prefix */
+      if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len,  msg_ps->vb_ptr->ident))
+      {
+        mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
+                               msg_ps->vb_ptr->ident + 4, &object_def);
+      }
+      else
+      {
+        mn = NULL;
+      }
+      if (mn != NULL)
+      {
+        if (mn->node_type == MIB_NODE_EX)
+        {
+          /* external object */
+          msg_ps->state = SNMP_MSG_EXTERNAL;
+        }
+        else
+        {
+          /* internal object */
+          msg_ps->state = SNMP_MSG_INTERNAL;
+        }
+      }
+      else
+      {
+        /* mn == NULL, noSuchName */
+        msg_ps->error_status = SNMP_ES_NOSUCHNAME;
+        msg_ps->error_index = 1 + msg_ps->vb_idx;
+        msg_ps->outvb.head = NULL;
+        msg_ps->outvb.tail = NULL;
+        msg_ps->outvb.count = 0;
+        msg_ps->outvb.seqlen = 0;
+        msg_ps->outvb.seqlenlen = 1;
+        snmp_send_response(msg_ps);
+        msg_ps->state = SNMP_MSG_EMPTY;
+      }
+    }
+    else if (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ)
+    {
+    }
+    else if (msg_ps->rt == SNMP_ASN1_PDU_SET_REQ)
+    {
+    }
+    else
+    {
+      /** @todo not a request, return generror?? */
+    }
+  }
+  else if (msg_ps->state == SNMP_MSG_INTERNAL)
+  {
+  }
+  else if (msg_ps->state == SNMP_MSG_EXTERNAL)
+  {
+  }
 }
 
 /* lwIP UDP receive callback function */
@@ -156,6 +223,8 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
       msg_ps->sp = port;
       /* demultiplex variable bindings */
       msg_ps->state = SNMP_MSG_DEMUX;
+      /* first variable binding from list to inspect */
+      msg_ps->vb_idx = 0;
       /* read UDP payload length from UDP header */
       payload_len = ntohs(udphdr->len) - UDP_HLEN;
 
@@ -171,7 +240,7 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
        /* Builds a list of variable bindings. Copy the varbinds from the pbuf
          chain to glue them when these are divided over two or more pbuf's. */
         err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps);
-        if (err_ret == ERR_OK)
+        if ((err_ret == ERR_OK) && (msg_ps->invb.count > 0))
         {          
           struct mib_node *mn;
           struct obj_def object_def;
@@ -183,14 +252,18 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
 
           if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ)
           { 
-            /** @todo check if count > 0 and if we got .iso.dod.internet  and iterate from vb 0 .. count-1 */
+            /** test object identifier for .iso.org.dod.internet prefix */
-            mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->invb.head->ident_len - 2 /* trim iso.dod.internet */,
+            if (snmp_iso_prefix_tst(msg_ps->invb.head->ident_len, msg_ps->invb.head->ident))
-                                   msg_ps->invb.head->ident + 2, &object_def);
+            {
+              mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->invb.head->ident_len - 4,
+                                     msg_ps->invb.head->ident + 4, &object_def);
+            }
+            else
+            {
+              mn = NULL;
+            }
             if (mn != NULL)
             {
-              LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv mn=%p sys_tem=%p node_typ=%"U16_F,
-                                            (void*)mn,(void*)&sys_tem,(u16_t)mn->node_type));
-          
               if (msg_ps->invb.head->value != NULL)
               {
                 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv free value before vb recycle"));
@@ -201,7 +274,7 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
               msg_ps->invb.head->value = mem_malloc(object_def.v_len);
               if (msg_ps->invb.head->value != NULL)
               {
-                mn->get_value(object_def.id_inst_len, object_def.id_inst_ptr, object_def.v_len, msg_ps->invb.head->value);
+                mn->get_value(&object_def, object_def.v_len, msg_ps->invb.head->value);
               }
               else
               {
@@ -213,8 +286,7 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
             {
               /* mn == NULL, noSuchName */
               msg_ps->error_status = SNMP_ES_NOSUCHNAME;
-              /** @todo current varbind index */
+              msg_ps->error_index = 1 + msg_ps->vb_idx;
-              msg_ps->error_index = 1;
               msg_ps->outvb.head = NULL;
               msg_ps->outvb.tail = NULL;
               msg_ps->outvb.count = 0;
@@ -232,6 +304,10 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
             msg_ps->error_index = 0;
           }
 
+/* when more variable bindings left msg_ps->state = SNMP_MSG_DEMUX */
+
+
+/* when completed transaction */
           err_ret = snmp_send_response(msg_ps);
           if (err_ret == ERR_MEM)
           {
@@ -247,13 +323,21 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
           /* free varbinds (if available) */
           snmp_varbind_list_free(&msg_ps->invb);
           msg_ps->state = SNMP_MSG_EMPTY;
+
         }
         else
         {
-          /* varbind-list decode failed! */
+          /* varbind-list decode failed, or varbind list empty (silly cmd for agent) */
           pbuf_free(p);
-          /** @todo should  we return SNMP_ES_GENERROR here ? */
           LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed"));
+          msg_ps->error_status = SNMP_ES_GENERROR;
+          msg_ps->error_index = 0;
+          msg_ps->outvb.head = NULL;
+          msg_ps->outvb.tail = NULL;
+          msg_ps->outvb.count = 0;
+          msg_ps->outvb.seqlen = 0;
+          msg_ps->outvb.seqlenlen = 1;
+          snmp_send_response(msg_ps);
         }
       }
       else
@@ -306,14 +390,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
     snmp_inc_snmpinasnparseerrs();
     return ERR_ARG;
   }
-  if (type & SNMP_ASN1_CONSTR)
-  {
   ofs += (1 + len_octets);
-  }
-  else
-  {
-    ofs += (1 + len_octets + len);
-  }
   snmp_asn1_dec_type(p, ofs, &type);
   derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
   if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
@@ -335,14 +412,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
     snmp_inc_snmpinbadversions();
     return ERR_ARG;
   }
-  if (type & SNMP_ASN1_CONSTR)
-  {
-    ofs += (1 + len_octets);
-  }
-  else
-  {
   ofs += (1 + len_octets + len);
-  }
   snmp_asn1_dec_type(p, ofs, &type);
   derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
   if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR)))
@@ -369,14 +439,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
     /** @todo: send authentication failure trap, if we have a trap destination */
     return ERR_ARG;
   }
-  if (type & SNMP_ASN1_CONSTR)
-  {
-    ofs += (1 + len_octets);
-  }
-  else
-  {
   ofs += (1 + len_octets + len);
-  }
   snmp_asn1_dec_type(p, ofs, &type);
   derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
   if (derr != ERR_OK)
@@ -422,14 +485,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
     return ERR_ARG;
   }
   m_stat->rt = type & 0x1F;
-  if (type & SNMP_ASN1_CONSTR)
-  {
   ofs += (1 + len_octets);
-  }
-  else
-  {
-    ofs += (1 + len_octets + len);
-  }
   snmp_asn1_dec_type(p, ofs, &type);
   derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
   if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
@@ -445,14 +501,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
     snmp_inc_snmpinasnparseerrs();
     return ERR_ARG;
   }
-  if (type & SNMP_ASN1_CONSTR)
-  {
-    ofs += (1 + len_octets);
-  }
-  else
-  {
   ofs += (1 + len_octets + len);
-  }
   snmp_asn1_dec_type(p, ofs, &type);
   derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
   if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
@@ -488,14 +537,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
       snmp_inc_snmpingenerrs();
       break;
   }
-  if (type & SNMP_ASN1_CONSTR)
-  {
-    ofs += (1 + len_octets);
-  }
-  else
-  {
   ofs += (1 + len_octets + len);
-  }
   snmp_asn1_dec_type(p, ofs, &type);
   derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
   if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
@@ -505,14 +547,7 @@ snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret,
     return ERR_ARG;
   }
   /* skip 'error-index', usually 0 for incoming requests */
-  if (type & SNMP_ASN1_CONSTR)
-  {
-    ofs += (1 + len_octets);
-  }
-  else
-  {
   ofs += (1 + len_octets + len);
-  }
   *ofs_ret = ofs;
   return ERR_OK;
 }

src/include/lwip/snmp.h

@@ -49,19 +49,14 @@ struct snmp_obj_id
 };
 
 /* system */
-void snmp_set_sysdesr(u8_t* str, u8_t strlen);
+void snmp_set_sysdesr(u8_t* str, u8_t* strlen);
 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_get_sysuptime(u32_t *value);
-void snmp_set_syscontact(u8_t *ocstr, u8_t ocstrlen);
+void snmp_set_syscontact(u8_t *ocstr, u8_t *ocstrlen);
-void snmp_set_sysname(u8_t *ocstr, u8_t ocstrlen);
+void snmp_set_sysname(u8_t *ocstr, u8_t *ocstrlen);
-void snmp_set_syslocation(u8_t *ocstr, u8_t ocstrlen);
+void snmp_set_syslocation(u8_t *ocstr, u8_t *ocstrlen);
-/** externally supplied system functions 
-    @see lwip/doc/snmp_agent.txt */
-void snmp_store_syscontact(u8_t* ocstr, u8_t ocstrlen);
-void snmp_store_sysname(u8_t* ocstr, u8_t ocstrlen);
-void snmp_store_syslocation(u8_t* ocstr, u8_t ocstrlen);
 
 /* network interface */
 void snmp_add_ifinoctets(struct netif *ni, u32_t value); 
@@ -75,13 +70,22 @@ void snmp_inc_ifoutdiscards(struct netif *ni);
 
 /* IP */
 void snmp_inc_ipinreceives(void);
-void snmp_inc_ipindelivers(void);
+void snmp_inc_ipinhdrerrors(void);
-void snmp_inc_ipindiscards(void);
+void snmp_inc_ipinaddrerrors(void);
-void snmp_inc_ipoutdiscards(void);
-void snmp_inc_ipoutrequests(void);
-void snmp_inc_ipunknownprotos(void);
-void snmp_inc_ipnoroutes(void);
 void snmp_inc_ipforwdatagrams(void);
+void snmp_inc_ipinunknownprotos(void);
+void snmp_inc_ipindiscards(void);
+void snmp_inc_ipindelivers(void);
+void snmp_inc_ipoutrequests(void);
+void snmp_inc_ipoutdiscards(void);
+void snmp_inc_ipoutnoroutes(void);
+void snmp_inc_ipreasmreqds(void);
+void snmp_inc_ipreasmoks(void);
+void snmp_inc_ipreasmfails(void);
+void snmp_inc_ipfragoks(void);
+void snmp_inc_ipfragfails(void);
+void snmp_inc_ipfragcreates(void);
+void snmp_inc_iproutingdiscards(void);
 
 /* ICMP */
 void snmp_inc_icmpinmsgs(void);
@@ -158,15 +162,18 @@ void snmp_inc_snmpoutsetrequests(void);
 void snmp_inc_snmpoutgetresponses(void);
 void snmp_inc_snmpouttraps(void);
 void snmp_get_snmpgrpid_ptr(struct snmp_obj_id **oid);
+void snmp_set_snmpenableauthentraps(u8_t *value);
 
 /* LWIP_SNMP support not available */
 /* define everything to be empty */
 #else
 
 /* system */
+#define snmp_set_sysdesr(str, strlen)
+#define snmp_get_sysobjid_ptr(oid)
 #define snmp_inc_sysuptime()
 #define snmp_get_sysuptime(value)
-#define snmp_get_sysobjid_ptr(oid)
+
 
 /* network interface */
 #define snmp_add_ifinoctets(ni,value) 
@@ -180,13 +187,22 @@ void snmp_get_snmpgrpid_ptr(struct snmp_obj_id **oid);
 
 /* IP */
 #define snmp_inc_ipinreceives()
-#define snmp_inc_ipindelivers()
+#define snmp_inc_ipinhdrerrors()
-#define snmp_inc_ipindiscards()
+#define snmp_inc_ipinaddrerrors()
-#define snmp_inc_ipoutdiscards()
-#define snmp_inc_ipoutrequests()
-#define snmp_inc_ipunknownprotos()
-#define snmp_inc_ipnoroutes()
 #define snmp_inc_ipforwdatagrams()
+#define snmp_inc_ipinunknownprotos()
+#define snmp_inc_ipindiscards()
+#define snmp_inc_ipindelivers()
+#define snmp_inc_ipoutrequests()
+#define snmp_inc_ipoutdiscards()
+#define snmp_inc_ipoutnoroutes()
+#define snmp_inc_ipreasmreqds()
+#define snmp_inc_ipreasmoks()
+#define snmp_inc_ipreasmfails()
+#define snmp_inc_ipfragoks()
+#define snmp_inc_ipfragfails()
+#define snmp_inc_ipfragcreates()
+#define snmp_inc_iproutingdiscards()
 
 /* ICMP */
 #define snmp_inc_icmpinmsgs()
@@ -262,6 +278,7 @@ void snmp_get_snmpgrpid_ptr(struct snmp_obj_id **oid);
 #define snmp_inc_snmpoutgetresponses()
 #define snmp_inc_snmpouttraps()
 #define snmp_get_snmpgrpid_ptr(oid)
+#define snmp_set_snmpenableauthentraps(value)
 
 #endif
 

src/include/lwip/snmp_msg.h

@@ -208,8 +208,12 @@ struct snmp_msg_pstat
   u8_t community[SNMP_COMMUNITY_STR_LEN + 1];
   /* community string length (exclusive zero term) */
   u8_t com_strlen;
-  /* one out of MSG_EMPTY, MSG_DEMUX, MSG_MGMT, MSG_PRIVATE */
+  /* one out of MSG_EMPTY, MSG_DEMUX, MSG_INTERNAL, MSG_EXTERNAL */
   u8_t state;
+  /* index into input variable binding list */
+  u8_t vb_idx;
+  /* ptr into input variable binding list */
+  struct snmp_varbind *vb_ptr;
   /* list of variable bindings from input */
   struct snmp_varbind_root invb;
   /* list of variable bindings to output */
@@ -260,7 +264,8 @@ extern struct snmp_msg_trap trap_msg;
 
 /** Agent setup, start listening to port 161. */
 void snmp_init(void);
-
+/** Handles internal/external events. */
+void snmp_msg_event(struct snmp_msg_pstat *msg_ps);
 err_t snmp_send_response(struct snmp_msg_pstat *m_stat);
 err_t snmp_send_trap(struct ip_addr *dst, s8_t generic_trap, s32_t specific_trap);
 

src/include/lwip/snmp_structs.h

@@ -70,6 +70,8 @@ struct obj_def
   u8_t  id_inst_len;
   /* instance part of supplied object identifier */
   s32_t *id_inst_ptr; 
+  /* optional value address hint */
+  void *addr;
 };
 
 /** MIB const array node */
@@ -88,7 +90,7 @@ struct mib_node
   void (*get_object_def)(u8_t ident_len, s32_t *ident, struct obj_def *od);
   /** returns object value for the given object identifier,
      @note the caller must allocate at least len bytes for the value */
-  void (*get_value)(u8_t ident_len, s32_t *ident, u16_t len, void *value);
+  void (*get_value)(struct obj_def *od, u16_t len, void *value);
   /** @todo set_value() */
   /** One out of MIB_NODE_AR, MIB_NODE_LR or MIB_NODE_EX */
   const u8_t node_type;
@@ -102,7 +104,7 @@ struct mib_array_node
 {
   /* inherited "base class" */
   const void (*get_object_def)(u8_t ident_len, s32_t *ident, struct obj_def *od);
-  const void (*get_value)(u8_t ident_len, s32_t *ident, u16_t len, void *value);
+  const void (*get_value)(struct obj_def *od, u16_t len, void *value);
   const u8_t node_type;
   const u16_t maxlength;
 
@@ -117,7 +119,7 @@ struct mib_ram_array_node
 {
   /* inherited "base class" */
   void (*get_object_def)(u8_t ident_len, s32_t *ident, struct obj_def *od);
-  void (*get_value)(u8_t ident_len, s32_t *ident, u16_t len, void *value);
+  void (*get_value)(struct obj_def *od, u16_t len, void *value);
   u8_t node_type;
   u16_t maxlength;
 
@@ -140,7 +142,7 @@ struct mib_list_rootnode
 {
   /* inherited "base class" */
   void (*get_object_def)(u8_t ident_len, s32_t *ident, struct obj_def *od);
-  void (*get_value)(u8_t ident_len, s32_t *ident, u16_t len, void *value);
+  void (*get_value)(struct obj_def *od, u16_t len, void *value);
   u8_t node_type;
   u16_t maxlength;
 
@@ -157,13 +159,13 @@ struct mib_external_node
 {
   /* inherited "base class" */
   void (*get_object_def)(u8_t ident_len, s32_t *ident, struct obj_def *od);
-  void (*get_value)(u8_t ident_len, s32_t *ident, u16_t len, void *value);
+  void (*get_value)(struct obj_def *od, u16_t len, void *value);
   u8_t node_type;
   u16_t maxlength;
 
   /* aditional struct members */
   void (*req_object_def)(u8_t ident_len, s32_t *ident);
-  void (*getreq_value)(u8_t ident_len, s32_t *ident);
+  void (*getreq_value)(struct obj_def *od);
 
   /** compares object sub identifier with externally available id
       return zero when equal, nonzero when unequal */
@@ -174,6 +176,10 @@ struct mib_external_node
   u16_t count;
 };
 
+/** export MIB tree from mib2.c */
+extern const struct mib_array_node internet;
+
 struct mib_node* snmp_search_tree(struct mib_node *node, u8_t ident_len, s32_t *ident, struct obj_def *object_def);
+u8_t snmp_iso_prefix_tst(u8_t ident_len, s32_t *ident);
 
 #endif