From fd243b6e9e325e30582b8f4ec2a9fe3b100c1d4c Mon Sep 17 00:00:00 2001
From: Vojtech Vilimek <vojtech.vilimek@nic.cz>
Date: Wed, 25 Oct 2023 16:23:39 +0200
Subject: [PATCH] SNMP: Remove support for context

---
 proto/snmp/bgp_mib.c    |  33 +------------
 proto/snmp/config.Y     |  34 +------------
 proto/snmp/snmp.c       |  68 ++++++++------------------
 proto/snmp/snmp.h       |  21 --------
 proto/snmp/snmp_utils.c |  61 -----------------------
 proto/snmp/snmp_utils.h |   5 --
 proto/snmp/subagent.c   | 104 ++++------------------------------------
 proto/snmp/subagent.h   |  20 --------
 8 files changed, 34 insertions(+), 312 deletions(-)

diff --git a/proto/snmp/bgp_mib.c b/proto/snmp/bgp_mib.c
index 2e855b73..c02400fc 100644
--- a/proto/snmp/bgp_mib.c
+++ b/proto/snmp/bgp_mib.c
@@ -186,36 +186,6 @@ snmp_bgp_register(struct snmp_proto *p)
     /* snmp_register(struct snmp_proto *p, struct oid *oid, uint index, uint len, u8 is_instance, uint contid) */
     snmp_register(p, oid, 1, 0, SNMP_REGISTER_TREE, SNMP_DEFAULT_CONTEXT);
   }
-
-#if 0
-  u32 bgp_peer_entry[] = { 1, 15, 3, 1, 1 };
-  u32 bound = 24;
-  HASH_WALK(p->bgp_hash, next, peer)
-  {
-    if (peer->flags & SNMP_BGP_P_REGISTERED)
-      continue;
-
-    struct bgp_proto *bgp = (struct bgp_proto *) peer->config->c.proto;
-
-    struct snmp_register *registering = snmp_register_create(p, SNMP_BGP4_MIB);
-
-    struct oid *oid = mb_alloc(p->pool, snmp_oid_sizeof(9));
-    STORE_U8(oid->n_subid, 9);
-    STORE_U8(oid->prefix, SNMP_MGMT);
-
-    for (uint i = 0; i < ARRAY_SIZE(bgp_peer_entry); i++)
-      STORE_U32(oid->ids[i], bgp_peer_entry[i]);
-    ip4_to_oid(oid, ipa_to_ip4(bgp->remote_ip));
-
-    /* index is position of x in .1.3.6.1.2.15.3.1.x (1-based) */
-    snmp_register(p, oid, bound, 9, SNMP_REGISTER_INSTANCE, peer->context_id);
-
-    registering->oid = oid;
-    add_tail(&p->register_queue, &registering->n);
-    p->register_to_ack++;
-  }
-  HASH_WALK_END;
-#endif
 }
 
 static int
@@ -959,7 +929,6 @@ bgp_fill_dynamic(struct snmp_proto UNUSED *p, struct agentx_varbind *vb,
 {
   struct oid *oid = &vb->name;
   uint size = c->size - snmp_varbind_header_size(vb);
-  uint UNUSED contid = c->context;
   byte *pkt;
 
   ip_addr addr;
@@ -1219,7 +1188,7 @@ snmp_bgp_fill(struct snmp_proto *p, struct agentx_varbind *vb,
   byte *pkt;
   if (is_static(state))
   {
-    pkt = bgp_fill_static(p, vb, c->buffer, c->size, c->context, c->byte_ord, state);
+    pkt = bgp_fill_static(p, vb, c->buffer, c->size, 0, c->byte_ord, state);
     ADVANCE(c->buffer, c->size, pkt - c->buffer);
     return;
   }
diff --git a/proto/snmp/config.Y b/proto/snmp/config.Y
index 303a261c..d8fa3319 100644
--- a/proto/snmp/config.Y
+++ b/proto/snmp/config.Y
@@ -16,8 +16,6 @@ CF_DEFINES
 
 #define SNMP_CFG ((struct snmp_config *) this_proto)
 
-struct snmp_bond *this_bond = NULL;
-
 CF_DECLS
 
 CF_KEYWORDS(SNMP, PROTOCOL, BPG, LOCAL, AS, REMOTE, ADDRESS, PORT, DESCRIPTION,
@@ -69,8 +67,6 @@ snmp_proto_start: proto_start SNMP
 
   init_list(&SNMP_CFG->bgp_entries);
   SNMP_CFG->bonds = 0;
-  /* We always have the default context */
-  SNMP_CFG->contexts = 1;
 
   SNMP_CFG->local_ip = IPA_NONE;
   SNMP_CFG->remote_ip = ipa_build4(127,0,0,1);
@@ -86,34 +82,10 @@ snmp_proto_start: proto_start SNMP
 
 proto_name ;
 
-snmp_context:
-   /* empty */	  {
-    if (!this_bond)
-      this_bond = cfg_alloc(sizeof(struct snmp_bond));
-
-    this_bond->context = NULL;
-  }
- | CONTEXT DEFAULT {
-    if (!this_bond)
-      this_bond = cfg_alloc(sizeof(struct snmp_bond));
-
-    this_bond->context = NULL;
-  }
- | CONTEXT text {
-    if(!this_bond)
-      this_bond = cfg_alloc(sizeof(struct snmp_bond));
-
-    this_bond->context = $2;
-    SNMP_CFG->contexts++;
-  }
- ;
-
-snmp_bgp_bond: BGP symbol snmp_context
+snmp_bgp_bond: BGP symbol
 {
   /* the snmp_context rule sets the correct value of this_bond */
-  if (!this_bond)
-    this_bond = cfg_alloc(sizeof(struct snmp_bond));
-
+  struct snmp_bond *this_bond = cfg_alloc(sizeof(struct snmp_bond));
   this_bond->type = SNMP_BGP;
 
   cf_assert_symbol($2, SYM_PROTO);
@@ -122,8 +94,6 @@ snmp_bgp_bond: BGP symbol snmp_context
   if (!this_bond->proto) cf_error("BGP protocol %s not found", $2->name);
   add_tail(&SNMP_CFG->bgp_entries, &this_bond->n);
   SNMP_CFG->bonds++;
-
-  this_bond = NULL;
 }
 
 CF_CODE
diff --git a/proto/snmp/snmp.c b/proto/snmp/snmp.c
index ef041201..94118ce0 100644
--- a/proto/snmp/snmp.c
+++ b/proto/snmp/snmp.c
@@ -120,10 +120,6 @@ snmp_init(struct proto_config *CF)
 
   p->timeout = cf->timeout;
 
-  /* used when assigning the context ids in s_cont_create() */
-  p->context_max = 1;
-  p->context_id_map = NULL;
-
   return P;
 }
 
@@ -160,9 +156,6 @@ snmp_cleanup(struct snmp_proto *p)
   }
 
   HASH_FREE(p->bgp_hash);
-  HASH_FREE(p->context_hash);
-  mb_free(p->context_id_map);
-  p->context_id_map = NULL;
 
   rfree(p->lp);
   p->bgp_trie = NULL;
@@ -196,15 +189,6 @@ snmp_connected(sock *sk)
   tm_set(p->ping_timer, current_time() + p->timeout S);
 }
 
-/* this function is internal and shouldn't be used outside the snmp module */
-void
-snmp_reconnect(timer *tm)
-{
-  struct snmp_proto *p = tm->data;
-  ASSUME(p->sock);
-  snmp_connected(p->sock);
-}
-
 /* this function is internal and shouldn't be used outside the snmp module */
 void
 snmp_sock_disconnect(struct snmp_proto *p, int reconnect)
@@ -274,6 +258,27 @@ snmp_start_locked(struct object_lock *lock)
     tm_set(p->startup_timer, current_time() + p->timeout S);
 }
 
+/* this function is internal and shouldn't be used outside the snmp module */
+void
+snmp_reconnect(timer *tm)
+{
+  struct snmp_proto *p = tm->data;
+  if (p->state == SNMP_STOP ||
+      p->state == SNMP_DOWN)
+    return;
+
+  // TODO is SNMP_RESET really needed ?
+  if (p->state == SNMP_INIT ||
+      p->state == SNMP_RESET)
+    snmp_startup(p);
+
+  if (!p->sock)
+    snmp_start_locked(p->lock);
+  else
+    snmp_connected(p->sock);
+}
+
+
 /* this function is internal and shouldn't be used outside the snmp module */
 void
 snmp_startup(struct snmp_proto *p)
@@ -359,20 +364,6 @@ snmp_start(struct proto *P)
 
   /* We create copy of bonds to BGP protocols. */
   HASH_INIT(p->bgp_hash, p->pool, 10);
-  HASH_INIT(p->context_hash, p->pool, 10);
-
-  /* We always have at least the default context */
-  p->context_id_map_size = cf->contexts;
-  p->context_id_map = mb_allocz(p->pool, cf->contexts * sizeof(struct snmp_context *));
-  //log(L_INFO "number of context allocated %d", cf->contexts);
-
-  struct snmp_context *defaultc = mb_alloc(p->pool, sizeof(struct snmp_context));
-  defaultc->context = "";
-  defaultc->context_id = 0;
-  defaultc->flags = 0; /* TODO Default context fl. */
-  HASH_INSERT(p->context_hash, SNMP_H_CONTEXT, defaultc);
-
-  p->context_id_map[0] = defaultc;
 
   struct snmp_bond *b;
   WALK_LIST(b, cf->bgp_entries)
@@ -391,18 +382,9 @@ snmp_start(struct proto *P)
       trie_add_prefix(p->bgp_trie, &net, IP4_MAX_PREFIX_LENGTH, IP4_MAX_PREFIX_LENGTH);
 
       HASH_INSERT(p->bgp_hash, SNMP_HASH, peer);
-
-      /* Handle non-default context */
-      if (b->context)
-      {
-	const struct snmp_context *c = snmp_cont_create(p, b->context);
-	peer->context_id = c->context_id;
-      }
     }
   }
 
-  ASSUME(cf->contexts == p->context_max);
-
   snmp_startup(p);
   return PS_START;
 }
@@ -421,14 +403,6 @@ snmp_reconfigure(struct proto *P, struct proto_config *CF)
     {
       if (!strcmp(b1->proto->name, b2->proto->name))
 	goto skip;
-
-      /* Both bonds use default context */
-      if (!b1->context && !b2->context)
-	goto skip;
-
-      /* Both bonds use same non-default context */
-      if (b1->context && b2->context && !strcmp(b1->context, b2->context))
-	goto skip;
     }
 
     return 0;
diff --git a/proto/snmp/snmp.h b/proto/snmp/snmp.h
index ebdd9b5f..f8e12f70 100644
--- a/proto/snmp/snmp.h
+++ b/proto/snmp/snmp.h
@@ -52,17 +52,10 @@ enum snmp_proto_state {
 /* hash table only store ip4 addresses */
 #define SNMP_HASH_LESS(ip1, ip2) SNMP_HASH_LESS4(ip1,ip2)
 
-/* context hash table macros */
-#define SNMP_H_CONTEXT_KEY(c)		c->context
-#define SNMP_H_CONTEXT_NEXT(c)		c->next
-#define SNMP_H_CONTEXT_EQ(s1,s2)	strcmp(s1,s2)
-#define SNMP_H_CONTEXT_FN(s)		mem_hash(s, strlen(s))
-
 struct snmp_bond {
   node n;
   struct proto_config *proto;
   u8 type;
-  const char *context;
 };
 
 struct snmp_config {
@@ -79,7 +72,6 @@ struct snmp_config {
   u8 priority;
   //struct iface *iface;
   u32 bonds;
-  uint contexts; /* Number of all conetexts including the default */
   const char *description;
   list bgp_entries;
   // TODO add support for subagent oid identification
@@ -91,7 +83,6 @@ struct snmp_config {
 struct snmp_bgp_peer {
   const struct bgp_config *config;
   ip_addr peer_ip;
-  uint context_id;
   u8 flags;
   struct snmp_bgp_peer *next;
 };
@@ -110,14 +101,6 @@ struct snmp_registered_oid {
   struct oid *oid;
 };
 
-struct snmp_context {
-  const char *context; /* string name */
-  //uint length; /* strlen() of name */
-  uint context_id;
-  u8 flags;
-  struct snmp_context *next;
-};
-
 struct snmp_proto {
   struct proto p;
   struct object_lock *lock;
@@ -149,10 +132,6 @@ struct snmp_proto {
   // map
   struct f_trie *bgp_trie;
   HASH(struct snmp_bgp_peer) bgp_hash;
-  HASH(struct snmp_context) context_hash;
-  struct snmp_context **context_id_map;
-  uint context_id_map_size;
-  uint context_max;
   struct tbf rl_gen;
 
   timer *ping_timer;
diff --git a/proto/snmp/snmp_utils.c b/proto/snmp/snmp_utils.c
index 43f2bc89..7a13fe38 100644
--- a/proto/snmp/snmp_utils.c
+++ b/proto/snmp/snmp_utils.c
@@ -170,14 +170,6 @@ snmp_test_varbind(const struct agentx_varbind *vb)
     return 0;
 }
 
-/*
-inline uint
-snmp_context_size(struct agentx_context *c)
-{
-  return (c && c->length) ? snmp_str_size_from_len(c->length) : 0;
-}
-*/
-
 struct agentx_varbind *
 snmp_create_varbind(byte *buf, struct oid *oid)
 {
@@ -575,56 +567,3 @@ snmp_search_res_to_type(enum snmp_search_res r)
   return type_arr[r];
 }
 
-inline const struct snmp_context *
-snmp_cont_find(struct snmp_proto *p, const char *name)
-{
-  u32 *ptr = mb_alloc(p->p.pool, 4 * sizeof(u32));
-  *ptr = 1;
-  ptr[2] = 4;
-  (void)ptr[1]; (void)ptr[0]; (void)ptr[2];
-  mb_free(ptr);
-  return HASH_FIND(p->context_hash, SNMP_H_CONTEXT, name);
-}
-
-inline const struct snmp_context *
-snmp_cont_get(struct snmp_proto *p, uint cont_id)
-{
-  if (cont_id >= p->context_max)
-    return NULL;
-
-  return p->context_id_map[cont_id];
-}
-
-inline const struct snmp_context *
-snmp_cont_create(struct snmp_proto *p, const char *name)
-{
-  const struct snmp_context *c = snmp_cont_find(p, name);
-
-  if (c)
-    return c;
-
-  struct snmp_context *c2;
-  c2 = mb_alloc(p->p.pool, sizeof(struct snmp_context));
-  c2->context = name;
-  c2->context_id = p->context_max++;
-  c2->flags = 0;
-
-  u32 *ptr = mb_alloc(p->p.pool, 4 * sizeof(u32));
-  *ptr = 1;
-  ptr[2] = 4;
-  (void)ptr[1]; (void)ptr[0]; (void)ptr[2];
-  mb_free(ptr);
-
-  HASH_INSERT(p->context_hash, SNMP_H_CONTEXT, c2);
-
-  if (c2->context_id >= p->context_id_map_size)
-  {
-    // TODO: allocate more than needed for better speed
-    p->context_id_map_size = c2->context_id + 1;
-    p->context_id_map = mb_realloc(p->context_id_map, p->context_id_map_size * sizeof(struct snmp_context *));
-  }
-
-  p->context_id_map[c2->context_id] = c2;
-
-  return c2;
-}
diff --git a/proto/snmp/snmp_utils.h b/proto/snmp/snmp_utils.h
index deeb7b9b..733cbabe 100644
--- a/proto/snmp/snmp_utils.h
+++ b/proto/snmp/snmp_utils.h
@@ -15,7 +15,6 @@ uint snmp_varbind_hdr_size_from_oid(struct oid *oid);
 uint snmp_varbind_header_size(struct agentx_varbind *vb);
 uint snmp_varbind_size(struct agentx_varbind *vb, int byte_ord);
 int snmp_test_varbind(const struct agentx_varbind *vb);
-//uint snmp_context_size(struct agentx_context *c);
 
 void snmp_oid_copy(struct oid *dest, const struct oid *src);
 
@@ -58,10 +57,6 @@ byte *snmp_varbind_nstr(struct agentx_varbind *vb, uint size, const char *str, u
 
 void snmp_dump_packet(byte *pkt, uint size);
 
-const struct snmp_context *snmp_cont_find(struct snmp_proto *p, const char *name);
-const struct snmp_context *snmp_cont_get(struct snmp_proto *p, uint context_id);
-const struct snmp_context *snmp_cont_create(struct snmp_proto *p, const char *name);
-
 enum agentx_type snmp_search_res_to_type(enum snmp_search_res res);
 
 int agentx_type_size(enum agentx_type t);
diff --git a/proto/snmp/subagent.c b/proto/snmp/subagent.c
index 3404c568..84a6b1c1 100644
--- a/proto/snmp/subagent.c
+++ b/proto/snmp/subagent.c
@@ -237,7 +237,7 @@ de_allocate_pdu(struct snmp_proto *p, struct oid *oid, u8 type)
 
 /* Register-PDU / Unregister-PDU */
 static void
-un_register_pdu(struct snmp_proto *p, struct oid *oid, uint len, uint index, u8 type, u8 is_instance, uint contid)
+un_register_pdu(struct snmp_proto *p, struct oid *oid, uint len, uint index, u8 type, u8 is_instance, uint UNUSED contid)
 {
   const struct snmp_config *cf = SKIP_BACK(struct snmp_config, cf, p->p.cf);
   sock *sk = p->sock;
@@ -246,13 +246,6 @@ un_register_pdu(struct snmp_proto *p, struct oid *oid, uint len, uint index, u8
   /* conditional +4 for upper-bound (optinal field) */
   uint sz = AGENTX_HEADER_SIZE + snmp_oid_size(oid) + ((len > 1) ? 4 : 0);
 
-  const struct snmp_context *sc = NULL;
-  if (contid)
-  {
-    sc = snmp_cont_get(p, contid);
-    sz += snmp_str_size(sc->context);
-  }
-
   if (c.size < sz)
     snmp_manage_tbuf(p, &c);
 
@@ -264,8 +257,6 @@ un_register_pdu(struct snmp_proto *p, struct oid *oid, uint len, uint index, u8
   SNMP_SESSION(h, p);
   c.byte_ord = h->flags & AGENTX_NETWORK_BYTE_ORDER;
 
-  SNMP_NON_DEFAULT_CONTEXT(h, c, contid);
-
   struct agentx_un_register_hdr *ur = (struct agentx_un_register_hdr *) c.buffer;
 
   /* do not override timeout */
@@ -347,8 +338,6 @@ parse_close_pdu(struct snmp_proto *p, byte * const pkt_start, uint size)
     return AGENTX_HEADER_SIZE;
   }
 
-  /* The agentx-Close-PDU must not have non-default context */
-
   snmp_simple_response(p, AGENTX_RES_NO_ERROR, 0);
   snmp_sock_disconnect(p, 1); // TODO: should we try to reconnect (2nd arg) ??
   return AGENTX_HEADER_SIZE;
@@ -383,7 +372,7 @@ snmp_testset(struct snmp_proto *p, const struct agentx_varbind *vb, struct oid *
 #if 0
 static void UNUSED
 addagentcaps_pdu(struct snmp_proto *p, struct oid *cap, char *descr,
-		 uint descr_len, struct agentx_context *c)
+		 uint descr_len)
 {
   ASSUME(descr != NULL && descr_len > 0);
   sock *sk = p->sock;
@@ -393,7 +382,7 @@ addagentcaps_pdu(struct snmp_proto *p, struct oid *cap, char *descr,
   byte *buf = sk->tpos;
   uint size = sk->tbuf + sk->tbsize - sk->tpos;
 
-  if (size < AGENTX_HEADER_SIZE + snmp_context_size(c) + snmp_oid_size(cap) + snmp_str_size_from_len(descr_len))
+  if (size < AGENTX_HEADER_SIZE + snmp_oid_size(cap) + snmp_str_size_from_len(descr_len))
   {
     /* TO-DO need more mem */
     return;
@@ -409,7 +398,6 @@ addagentcaps_pdu(struct snmp_proto *p, struct oid *cap, char *descr,
   if (c && c->length)
   {
     SNMP_HAS_CONTEXT(h);
-    in_pkt = snmp_put_nstr(buf, c->context, c->length) - buf;
     ADVANCE(buf, size, in_pkt);
   }
 
@@ -426,7 +414,7 @@ addagentcaps_pdu(struct snmp_proto *p, struct oid *cap, char *descr,
 }
 
 static void UNUSED
-removeagentcaps_pdu(struct snmp_proto *p, struct oid *cap, struct agentx_context *c)
+removeagentcaps_pdu(struct snmp_proto *p, struct oid *cap)
 {
   sock *sk = p->sock;
 
@@ -436,7 +424,7 @@ removeagentcaps_pdu(struct snmp_proto *p, struct oid *cap, struct agentx_context
   byte *buf = sk->tpos;
   uint size = sk->tbuf + sk->tbsize - sk->tpos;
 
-  if (size < AGENTX_HEADER_SIZE + snmp_context_size(c) + snmp_oid_size(cap))
+  if (size < AGENTX_HEADER_SIZE + snmp_oid_size(cap))
   {
     /* TO-DO need more mem */
     return;
@@ -451,7 +439,6 @@ removeagentcaps_pdu(struct snmp_proto *p, struct oid *cap, struct agentx_context
   if (c && c->length)
   {
     SNMP_HAS_CONTEXT(h);
-    in_pkt = snmp_put_nstr(buf, c->context, c->length) - buf;
     ADVANCE(buf, size, in_pkt);
   }
 
@@ -492,30 +479,12 @@ parse_test_set_pdu(struct snmp_proto *p, byte * const pkt_start, uint size)
 
   res = prepare_response(p, &c);
 
-  uint clen;
-  const char *context;
-  SNMP_LOAD_CONTEXT(h, pkt, context, clen);
-
-  if (size < clen)
-    return 0;
-
-  if (pkt_size < clen)
-  {
-    c.error = AGENTX_RES_PARSE_ERROR;
-
-    goto error;
-  }
-
-  ADVANCE(pkt, pkt_size, clen);
-  size -= clen;
-
   /* 0 if there is piece, that we cannot set */
   int all_possible = 0;
   /* the all_possible is currently hard-coded with no support for writing to mib
    * variables, when implementing the mentioned support, change the initializer
    * to 1
    */
-
 #if 0
   // TODO think about future value setting data structure
   //struct agentx_transaction *tr = mb_alloc(...);
@@ -554,7 +523,7 @@ parse_test_set_pdu(struct snmp_proto *p, byte * const pkt_start, uint size)
   }
   mb_free(tr);
 #endif
-
+  goto error;
 error:
   s = update_packet_size(p, sk->tpos, c.buffer);
 
@@ -601,22 +570,12 @@ parse_set_pdu(struct snmp_proto *p, byte * const pkt_start, uint size, uint err)
 
   struct agentx_response *r = prepare_response(p, &c);
 
-  uint clen;
-  const char *context;
-  SNMP_LOAD_CONTEXT(h, pkt, context, clen);
-
-  if (size < snmp_str_size_from_len(clen))
-    return 0;
-
   if (size < pkt_size)
   {
     c.error = AGENTX_RES_PARSE_ERROR;
     goto error;
   }
 
-  ADVANCE(pkt, size, snmp_str_size_from_len(clen));
-  // TODO: work with context
-
   // TODO: free resource allocated by parse_test_set_pdu()
   // TODO: do something meaningful
   //mb_free(tr);
@@ -891,14 +850,6 @@ do_response(struct snmp_proto *p, byte *buf, uint size)
       byte *pkt = buf;
       ADVANCE(pkt, size, AGENTX_HEADER_SIZE);
 
-      uint clen;
-      const char *context;
-      SNMP_LOAD_CONTEXT((struct agentx_header *) buf, pkt, context, clen);
-
-      if (size < snmp_str_size_from_len(clen))
-	return;
-
-      ADVANCE(pkt, size, snmp_str_size_from_len(clen));
       const struct oid *oid = (void *) pkt;
 
       snmp_register_ack(p, h, snmp_get_mib_class(oid));
@@ -1098,39 +1049,6 @@ parse_gets2_pdu(struct snmp_proto *p, byte * const pkt_start, uint size, uint *s
   // TODO better handling of endianness
   c.byte_ord = 0; /* use little-endian */
 
-  uint clen;	  /* count of characters in context (without last '\0') */
-  const char *context;  /* pointer to RX-buffer context */
-
-  /* moves with pkt; assign context, clen */
-  SNMP_LOAD_CONTEXT(h, pkt, context, clen);
-
-  /*
-   * We need more data; for valid response we need to know full
-   * header picture, including the context octet string
-   */
-  if (size < clen)
-    goto wait;
-
-  /*
-   * It is a malformed packet if the context octet string should be longer than
-   * whole packet.
-   */
-  if (pkt_size < clen)
-  {
-    c.error = AGENTX_RES_PARSE_ERROR;
-    c.index = 0;
-    ret = MIN(size, pkt_size + AGENTX_HEADER_SIZE);
-    goto error;
-  }
-
-  /* The RFC does not consider the context octet string as a part of a header */
-  ADVANCE(pkt, pkt_size, clen);
-  size -= clen;
-
-  /* FIXME add support for c.context hashing
-   c.context = ...
-   */
-
   /*
    * Get-Bulk processing stops if all the varbind have type END_OF_MIB_VIEW
    * has_any is true if some varbind has type other than END_OF_MIB_VIEW
@@ -1167,7 +1085,7 @@ parse_gets2_pdu(struct snmp_proto *p, byte * const pkt_start, uint size, uint *s
   if (c.size < sizeof(struct agentx_response))
   {
     snmp_manage_tbuf(p, &c);
-    // TODO renew pkt, pkt_start pointers context clen
+    // TODO renew pkt, pkt_start pointers
   }
 
   struct agentx_response *response_header = prepare_response(p, &c);
@@ -1309,11 +1227,9 @@ parse_gets2_pdu(struct snmp_proto *p, byte * const pkt_start, uint size, uint *s
   goto free;
 
 partial:
-  /* The context octet is not added into response pdu. */
-
   /* need to tweak RX buffer packet size */
   (c.byte_ord) ? put_u32(&h->payload, pkt_size) : (h->payload = pkt_size);
-  *skip = AGENTX_HEADER_SIZE + snmp_str_size_from_len(clen);
+  *skip = AGENTX_HEADER_SIZE;
 
   /* number of bytes parsed from RX-buffer */
   ret = pkt - pkt_start;
@@ -1472,7 +1388,7 @@ int snmp_search_check_end_oid(const struct oid *found, const struct oid *bound)
    working only with o_start, o_end allocated in heap (not from buffer)*/
 static struct oid *
 search_mib(struct snmp_proto *p, const struct oid *o_start, const struct oid *o_end,
-	   struct oid *o_curr, struct snmp_pdu *c,
+	   struct oid *o_curr, struct snmp_pdu UNUSED *c,
 	   enum snmp_search_res *result)
 {
   ASSUME(o_start != NULL);
@@ -1500,7 +1416,7 @@ search_mib(struct snmp_proto *p, const struct oid *o_start, const struct oid *o_
   switch (o_curr->ids[1])
   {
     case SNMP_BGP4_MIB:
-      r = snmp_bgp_search2(p, &o_curr, o_end, c->context);
+      r = snmp_bgp_search2(p, &o_curr, o_end, 0);
 
       if (r == SNMP_SEARCH_OK)
       {
diff --git a/proto/snmp/subagent.h b/proto/snmp/subagent.h
index 99bb12d7..77548f62 100644
--- a/proto/snmp/subagent.h
+++ b/proto/snmp/subagent.h
@@ -121,27 +121,9 @@ enum snmp_search_res {
   str[length] = '\0'; /* set term. char */				      \
   buf += 4 + snmp_str_size_from_len(length); })
 
-#define SNMP_LOAD_CONTEXT(hdr, buf, cont, cont_len) ({			      \
-  if (cont = NULL, cont_len = 0, (hdr)->flags & AGENTX_NON_DEFAULT_CONTEXT)   \
-    LOAD_STR((buf), (cont), (cont_len),					      \
-      (hdr)->flags & AGENTX_NETWORK_BYTE_ORDER); })
-
-#define SNMP_COPY_CONTEXT(proto, hdr, buf, cont, cont_len) ({		      \
-  cont = NULL; cont_len = 0;						      \
-  if (hdr->flags & AGENTX_NON_DEFAULT_CONTEXT)				      \
-    COPY_STR(proto, buf, cont, cont_len,				      \
-	(hdr)->flags & AGENTX_NETWORK_BYTE_ORDER) })
-
 #define SNMP_HAS_CONTEXT(hdr)						      \
   hdr->flags |= AGENTX_NON_DEFAULT_CONTEXT
 
-#define SNMP_NON_DEFAULT_CONTEXT(hdr,pdu,contid) ({			      \
-  if (contid) {								      \
-    SNMP_HAS_CONTEXT(hdr);						      \
-    snmp_put_str((c).buffer, (sc)->context);				      \
-    ADVANCE((c).buffer, (c).size, snmp_str_size((sc)->context));	      \
-  } })
-
 #define SNMP_PUT_OID(buf, size, oid, byte_ord)				      \
   ({									      \
     struct agentx_varbind *vb = (void *) buf;				      \
@@ -158,7 +140,6 @@ enum snmp_search_res {
     .buffer = sk->tpos,							      \
     .size = sk->tbuf + sk->tbsize - sk->tpos,				      \
     .error = AGENTX_RES_NO_ERROR,					      \
-    .context = 0,							      \
     .index = 0,								      \
   }
 
@@ -314,7 +295,6 @@ enum agentx_response_err {
 struct snmp_pdu {
   byte *buffer;			    /* pointer to buffer */
   uint size;			    /* unused space in buffer */
-  uint context;			    /* context hash */
   int byte_ord;			    /* flag signaling NETWORK_BYTE_ORDER */
   enum agentx_response_err error;   /* storage for result of current action */
   uint index;			    /* index on which the error was found */