Testing Notify-PDU

proto/snmp/bgp_mib.c

@@ -70,9 +70,7 @@ snmp_bgp_register(struct snmp_proto *p)
     add_tail(&p->register_queue, &registering->n);
     p->register_to_ack++;
 
-    /* Function declartion:
+    /* snmp_register(struct snmp_proto *p, struct oid *oid, uint index, uint len, u8 is_instance) */
-     * snmp_register(struct snmp_proto *p, struct oid *oid, uint index, uint len, u8 is_instance);
-     */
     snmp_register(p, oid, 0, 1, 0);
   }
 }
@@ -114,11 +112,10 @@ bgp_get_candidate(u32 field)
   };
 
   /*
-   * First value is in secord cell of array translation_table (as the
+   * First value is in secord cell of array translation_table, as the
    * SNMP_BPG_IDENTIFIER == 1
    */
-  if (field > 0 &&
+  if (field > 0 && field <= sizeof(translation_table) / sizeof(translation_table[0]) - 1)
-      field <= sizeof(translation_table)/sizeof(translation_table[0]) - 1)
     return translation_table[field];
   if (field == 0)
     return BGP_INTERNAL_INVALID;
@@ -193,6 +190,7 @@ print_bgp_record_all(struct snmp_proto *p)
   snmp_log("dumping watched end");
 }
 
+
 /**
  * snmp_bgp_state - linearize oid from BGP4-MIB
  * @oid: prefixed object identifier from BGP4-MIB::bgp subtree
@@ -402,7 +400,7 @@ update_bgp_oid(struct oid *oid, u8 state)
       state == BGP_INTERNAL_NO_VALUE)
     return oid;
 
-  /* No need to reallocate anything if the OID is has same lin. state */
+  /* No need to reallocate anything if the OID has same lin. state */
   if (snmp_bgp_state(oid) == state)
   {
     if (state >= BGP_INTERNAL_IDENTIFIER &&
@@ -537,6 +535,7 @@ update_bgp_oid(struct oid *oid, u8 state)
     default:
       /* intentionally left blank */
       break;
+      //die("update unavailable");
   }
 
   return oid;
@@ -590,10 +589,7 @@ bgp_find_dynamic_oid(struct snmp_proto *p, struct oid *o_start, const struct oid
     if (cmp < 0 || (cmp == 0 && snmp_is_oid_empty(o_end)))
     {
       snmp_log("ip4_less() returned true");
-      struct oid *o = mb_allocz(p->p.pool, snmp_oid_sizeof(9));
+      struct oid *o = snmp_oid_duplicate(p->p.pool, o_start);
-      o->n_subid = 9;
-
-      memcpy(o, o_start, snmp_oid_size(o_start));
       snmp_oid_ip4_index(o, 5, net4_prefix(&net));
 
       return o;
@@ -627,7 +623,7 @@ UNUSED, u8 current_state)
     snmp_oid_dump(o_start);
 
     next_state = snmp_bgp_next_state(next_state);
-    /* We search in next state is done from beginning. */
+    /* The search in next state is done from beginning. */
     o_start->ids[5] = o_start->ids[6] = o_start->ids[7] = o_start->ids[8] = 0;
     o_start->include = 1;
 
@@ -647,7 +643,6 @@ UNUSED, u8 current_state)
 static int
 snmp_bgp_find_next_oid(struct snmp_proto *p, struct oid *oid, uint UNUSED contid)
 {
-  // TODO add o_end paramenter for faster searches
   ip4_addr ip4 = ip4_from_oid(oid);
   //ip_add4 dest = ip4_from_u32(0xFFFFFFFF);
 
@@ -722,7 +717,7 @@ snmp_bgp_search_dynamic(struct snmp_proto *p, struct oid **searched, const struc
     oid->ids[5] = oid->ids[6] = oid->ids[7] = oid->ids[8] = 0;
   }
 
-  if (next_state <= end_state)
+  if (next_state < BGP_INTERNAL_END && next_state <= end_state)
   {
     *searched = oid;
     return SNMP_SEARCH_OK;
@@ -740,6 +735,11 @@ snmp_bgp_search2(struct snmp_proto *p, struct oid **searched, const struct oid *
   struct oid *oid = *searched;
   snmp_log("snmp_bgp_search2() with state %s [%d]", debug_bgp_states[bgp_state], bgp_state);
 
+  if (bgp_state == BGP_INTERNAL_END)
+  {
+    return SNMP_SEARCH_NO_OBJECT;
+  }
+
   /* TODO remove todo below, then remove this code */
   if (is_dynamic(bgp_state))
   {
@@ -773,7 +773,8 @@ snmp_bgp_search2(struct snmp_proto *p, struct oid **searched, const struct oid *
 
   oid = *searched = update_bgp_oid(*searched, bgp_state);
   if (oid->n_subid == 3 && oid->ids[2] >= SNMP_BGP_VERSION &&
-      oid->ids[2] <= SNMP_BGP_LOCAL_AS)
+      oid->ids[2] <= SNMP_BGP_LOCAL_AS && bgp_state != BGP_INTERNAL_END)
+      //oid->ids[2] <= SNMP_BGP_LOCAL_AS && bgp_state != BGP_INTERNAL_END)
   {
     snmp_log("oid matches static state");
     oid->include = 0;
@@ -789,8 +790,8 @@ struct oid *
 snmp_bgp_search(struct snmp_proto *p, struct oid *o_start, struct oid *o_end, uint contid UNUSED)
 {
   u8 start_state = snmp_bgp_state(o_start);
-  //u8 state_curr = snmp_bgp_state(o_start);
+
-  //u8 state_end = (o_end) ? snmp_bgp_state(o_end) : 0;
+  // print debugging information
   print_bgp_record_all(p);
 
   if (o_start->include && snmp_bgp_has_value(start_state) &&
@@ -808,7 +809,7 @@ snmp_bgp_search(struct snmp_proto *p, struct oid *o_start, struct oid *o_end, ui
     return search_bgp_dynamic(p, o_start, o_end, contid, start_state);
   }
 
-  /* o_start->include == 0 */
+  /* o_start is not inclusive */
 
   u8 next_state = snmp_bgp_next_state(start_state);
   // TODO more checks ?!?
@@ -844,6 +845,8 @@ bgp_fill_dynamic(struct snmp_proto UNUSED *p, struct agentx_varbind *vb,
   }
 
   snmp_log(" -> ip addr %I", addr);
+  // TODO XXX deal with possible change of (remote) ip; BGP should restart and
+  // disappear
   struct snmp_bgp_peer *pe = HASH_FIND(p->bgp_hash, SNMP_HASH, addr);
 
   struct bgp_proto *bgp_proto = NULL;

proto/snmp/snmp.c

@@ -7,6 +7,68 @@
  *	Can be freely distributed and used under the terms of the GNU GPL.
  */
 
+/**
+ * Simple Network Management Protocol State Machine
+ *
+ *  States with main transitions
+ *
+ *
+ *    +-----------------+
+ *    | SNMP_INIT	|     entry state after call snmp_start()
+ *    +-----------------+
+ *	  |
+ *	  |   acquiring object lock for communication socket
+ *	  V
+ *    +-----------------+
+ *    | SNMP_LOCKED	|     object lock aquired
+ *    +-----------------+
+ *	  |
+ *	  |   opening communaiton socket
+ *	  V
+ *    +-----------------+
+ *    | SNMP_OPEN	|     socket created, starting subagent
+ *    +-----------------+
+ *	  |
+ *	  |   BIRD recieve response for Open-PDU
+ *	  V
+ *    +-----------------+
+ *    | SNMP_REGISTER   |     session was established, subagent registers MIBs
+ *    +-----------------+
+ *	  |
+ *	  |   subagent recieved responses for all registration requests
+ *	  V
+ *    +-----------------+
+ *    | SNMP_CONN	|     everything is set
+ *    +-----------------+
+ *	  |
+ * 	  |   function snmp_shutdown() is called, BIRD sends Close-PDU
+ *	  V
+ *    +-----------------+
+ *    | SNMP_STOP	|     waiting for response
+ *    +-----------------+
+ *	  |
+ *	  |   cleaning old state information
+ *	  V
+ *    +-----------------+
+ *    | SNMP_DOWN	|     session is closed
+ *    +-----------------+
+ *
+ *
+ *  Erroneous transitions:
+ *    SNMP is UP in states SNMP_CONN and also in SNMP_REGISTER because the
+ *    session is establised and the GetNext request should be responsed
+ *    without regard to MIB registration.
+ *
+ *    When the session has been closed for some reason (socket error, reciept of
+ *    Close-PDU) SNMP cleans the session information and message queue and goes
+ *    back to the SNMP_LOCKED state.
+ *
+ *    Reconfiguration is done in similar fashion to BGP, the reconfiguration
+ *    request is declined, the protocols is stoped and started with new
+ *    configuration.
+ *
+ */
+
 #include "nest/bird.h"
 #include "nest/cli.h"
 #include "nest/locks.h"
@@ -26,6 +88,15 @@ static void snmp_start_locked(struct object_lock *lock);
 static int snmp_shutdown(struct proto *P);
 
 static const char * const snmp_state[] = {
+  [SNMP_ERR]	    = "SNMP ERROR",
+  [SNMP_INIT]	    = "SNMP INIT",
+  [SNMP_LOCKED]	    = "SNMP LOCKED",
+  [SNMP_OPEN]	    = "SNMP CONNECTION OPENED",
+  [SNMP_REGISTER]   = "SNMP REGISTERING MIBS",
+  [SNMP_CONN]	    = "SNMP CONNECTED",
+  [SNMP_STOP]	    = "SNMP STOPING",
+  [SNMP_DOWN]	    = "SNMP DOWN",
+/*
   [SNMP_ERR]	      = "SNMP ERROR",
   [SNMP_DELAY]	      = "SNMP DELAY",
   [SNMP_INIT]	      = "SNMP INIT",
@@ -34,6 +105,7 @@ static const char * const snmp_state[] = {
   [SNMP_STOP]	      = "SNMP STOP",
   [SNMP_DOWN]	      = "SNMP DOWN",
   [SNMP_LISTEN]	      = "SNMP LISTEN",
+*/
 };
 
 static struct proto *
@@ -110,10 +182,12 @@ snmp_startup(struct snmp_proto *p)
 {
   //snmp_log("changing proto_snmp state to INIT");
 
-  if (p->state == SNMP_CONN ||
+  if (p->state == SNMP_LOCKED ||
-      p->state == SNMP_REGISTER)
+      p->state == SNMP_OPEN ||
+      p->state == SNMP_REGISTER ||
+      p->state == SNMP_CONN)
   {
-    snmp_log("startup() with invalid state %u", p->state);
+    snmp_log("startup() already in connected state %u", p->state);
     return;
   }
 
@@ -151,6 +225,8 @@ snmp_start_locked(struct object_lock *lock)
   snmp_log("snmp_start_locked() - lock acquired; preparing socket");
   struct snmp_proto *p = lock->data;
 
+  p->state = SNMP_LOCKED;
+
   sock *s = sk_new(p->p.pool);
   s->type = SK_TCP_ACTIVE;
   s->saddr = p->local_ip;
@@ -185,6 +261,9 @@ snmp_connected(sock *sk)
 {
   struct snmp_proto *p = sk->data;
   snmp_log("snmp_connected() connection created");
+
+  p->state = SNMP_OPEN;
+
   byte *buf UNUSED = sk->rpos;
 
   sk->rx_hook = snmp_rx;
@@ -392,8 +471,8 @@ snmp_shutdown(struct proto *P)
   tm_stop(p->ping_timer);
 
   /* connection established -> close the connection */
-  if (p->state == SNMP_CONN ||
+  if (p->state == SNMP_REGISTER ||
-      p->state == SNMP_REGISTER)
+      p->state == SNMP_CONN)
   {
     p->state = SNMP_STOP;
 
@@ -407,7 +486,6 @@ snmp_shutdown(struct proto *P)
 
     return PS_STOP;
   }
-
   /* no connection to close */
   else
   {
@@ -435,3 +513,4 @@ snmp_build(void)
 {
   proto_build(&proto_snmp);
 }
+

proto/snmp/snmp.h

@@ -31,6 +31,17 @@
 
 enum snmp_proto_state {
   SNMP_ERR = 0,
+
+  SNMP_INIT = 1,
+  SNMP_LOCKED,
+  SNMP_OPEN,
+  SNMP_REGISTER,
+  SNMP_CONN,
+  SNMP_STOP,
+  SNMP_DOWN,
+
+/*
+  SNMP_ERR = 0,
   SNMP_DELAY,
   SNMP_INIT,
   SNMP_REGISTER,
@@ -38,6 +49,8 @@ enum snmp_proto_state {
   SNMP_STOP,
   SNMP_DOWN,
   SNMP_LISTEN,
+  SNMP_RESET,
+*/
 };
 
 /* hash table macros */