3 * MIB tree access/construction functions.
7 * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
10 * Redistribution and use in source and binary forms, with or without modification,
11 * are permitted provided that the following conditions are met:
13 * 1. Redistributions of source code must retain the above copyright notice,
14 * this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
32 * Author: Christiaan Simons <christiaan.simons@axon.tv>
38 #include "lwip/snmp_structs.h"
43 /** .iso.org.dod.internet address prefix, @see snmp_iso_*() */
44 const s32_t prefix
[4] = {1, 3, 6, 1};
46 #define NODE_STACK_SIZE (LWIP_SNMP_OBJ_ID_LEN)
47 /** node stack entry (old news?) */
51 struct mib_node
* r_ptr
;
52 /** right child identifier */
54 /** right child next level */
57 static u8_t node_stack_cnt
= 0;
58 static struct nse node_stack
[NODE_STACK_SIZE
];
61 * Pushes nse struct onto stack.
64 push_node(struct nse
* node
)
66 LWIP_ASSERT("node_stack_cnt < NODE_STACK_SIZE",node_stack_cnt
< NODE_STACK_SIZE
);
67 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("push_node() node=%p id=%"S32_F
"\n",(void*)(node
->r_ptr
),node
->r_id
));
68 if (node_stack_cnt
< NODE_STACK_SIZE
)
70 node_stack
[node_stack_cnt
] = *node
;
76 * Pops nse struct from stack.
79 pop_node(struct nse
* node
)
81 if (node_stack_cnt
> 0)
84 *node
= node_stack
[node_stack_cnt
];
86 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("pop_node() node=%p id=%"S32_F
"\n",(void *)(node
->r_ptr
),node
->r_id
));
90 * Conversion from ifIndex to lwIP netif
91 * @param ifindex is a s32_t object sub-identifier
92 * @param netif points to returned netif struct pointer
95 snmp_ifindextonetif(s32_t ifindex
, struct netif
**netif
)
97 struct netif
*nif
= netif_list
;
102 while ((nif
!= NULL
) && (i
< ifidx
))
111 * Conversion from lwIP netif to ifIndex
112 * @param netif points to a netif struct
113 * @param ifindex points to s32_t object sub-identifier
116 snmp_netiftoifindex(struct netif
*netif
, s32_t
*ifidx
)
118 struct netif
*nif
= netif_list
;
131 * Conversion from oid to lwIP ip_addr
132 * @param ident points to s32_t ident[4] input
133 * @param ip points to output struct
136 snmp_oidtoip(s32_t
*ident
, struct ip_addr
*ip
)
151 * Conversion from lwIP ip_addr to oid
152 * @param ip points to input struct
153 * @param ident points to s32_t ident[4] output
156 snmp_iptooid(struct ip_addr
*ip
, s32_t
*ident
)
161 ident
[0] = (ipa
>> 24) & 0xff;
162 ident
[1] = (ipa
>> 16) & 0xff;
163 ident
[2] = (ipa
>> 8) & 0xff;
164 ident
[3] = ipa
& 0xff;
167 struct mib_list_node
*
168 snmp_mib_ln_alloc(s32_t id
)
170 struct mib_list_node
*ln
;
172 ln
= (struct mib_list_node
*)mem_malloc(sizeof(struct mib_list_node
));
184 snmp_mib_ln_free(struct mib_list_node
*ln
)
189 struct mib_list_rootnode
*
190 snmp_mib_lrn_alloc(void)
192 struct mib_list_rootnode
*lrn
;
194 lrn
= (struct mib_list_rootnode
*)mem_malloc(sizeof(struct mib_list_rootnode
));
197 lrn
->get_object_def
= noleafs_get_object_def
;
198 lrn
->get_value
= noleafs_get_value
;
199 lrn
->set_test
= noleafs_set_test
;
200 lrn
->set_value
= noleafs_set_value
;
201 lrn
->node_type
= MIB_NODE_LR
;
211 snmp_mib_lrn_free(struct mib_list_rootnode
*lrn
)
217 * Inserts node in idx list in a sorted
218 * (ascending order) fashion and
219 * allocates the node if needed.
221 * @param rn points to the root node
222 * @param objid is the object sub identifier
223 * @param insn points to a pointer to the inserted node
224 * used for constructing the tree.
225 * @return -1 if failed, 1 if inserted, 2 if present.
228 snmp_mib_node_insert(struct mib_list_rootnode
*rn
, s32_t objid
, struct mib_list_node
**insn
)
230 struct mib_list_node
*nn
;
233 LWIP_ASSERT("rn != NULL",rn
!= NULL
);
235 /* -1 = malloc failure, 0 = not inserted, 1 = inserted, 2 = was present */
237 if (rn
->head
== NULL
)
239 /* empty list, add first node */
240 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("alloc empty list objid==%"S32_F
"\n",objid
));
241 nn
= snmp_mib_ln_alloc(objid
);
256 struct mib_list_node
*n
;
257 /* at least one node is present */
259 while ((n
!= NULL
) && (insert
== 0))
261 if (n
->objid
== objid
)
263 /* node is already there */
264 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("node already there objid==%"S32_F
"\n",objid
));
268 else if (n
->objid
< objid
)
272 /* alloc and insert at the tail */
273 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("alloc ins tail objid==%"S32_F
"\n",objid
));
274 nn
= snmp_mib_ln_alloc(objid
);
286 /* insertion failure */
292 /* there's more to explore: traverse list */
293 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("traverse list\n"));
299 /* n->objid > objid */
300 /* alloc and insert between n->prev and n */
301 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("alloc ins n->prev, objid==%"S32_F
", n\n",objid
));
302 nn
= snmp_mib_ln_alloc(objid
);
307 /* insert at the head */
315 /* insert in the middle */
326 /* insertion failure */
336 LWIP_ASSERT("insert != 0",insert
!= 0);
341 * Finds node in idx list and returns deletion mark.
343 * @param rn points to the root node
344 * @param objid is the object sub identifier
345 * @param fn returns pointer to found node
346 * @return 0 if not found, 1 if deletable,
347 * 2 can't delete (2 or more children), 3 not a list_node
350 snmp_mib_node_find(struct mib_list_rootnode
*rn
, s32_t objid
, struct mib_list_node
**fn
)
353 struct mib_list_node
*n
;
355 LWIP_ASSERT("rn != NULL",rn
!= NULL
);
357 while ((n
!= NULL
) && (n
->objid
!= objid
))
365 else if (n
->nptr
== NULL
)
367 /* leaf, can delete node */
372 struct mib_list_rootnode
*rn
;
374 if (n
->nptr
->node_type
== MIB_NODE_LR
)
376 rn
= (struct mib_list_rootnode
*)n
->nptr
;
379 /* can't delete node */
384 /* count <= 1, can delete node */
390 /* other node type */
399 * Removes node from idx list
400 * if it has a single child left.
402 * @param rn points to the root node
403 * @param n points to the node to delete
404 * @return the nptr to be freed by caller
406 struct mib_list_rootnode
*
407 snmp_mib_node_delete(struct mib_list_rootnode
*rn
, struct mib_list_node
*n
)
409 struct mib_list_rootnode
*next
;
411 LWIP_ASSERT("rn != NULL",rn
!= NULL
);
412 LWIP_ASSERT("n != NULL",n
!= NULL
);
414 /* caller must remove this sub-tree */
415 next
= (struct mib_list_rootnode
*)(n
->nptr
);
423 /* not last node, new list begin */
424 n
->next
->prev
= NULL
;
427 else if (n
== rn
->tail
)
432 /* not last node, new list end */
433 n
->prev
->next
= NULL
;
438 /* node must be in the middle */
439 n
->prev
->next
= n
->next
;
440 n
->next
->prev
= n
->prev
;
442 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("free list objid==%"S32_F
"\n",n
->objid
));
455 * Searches tree for the supplied (scalar?) object identifier.
457 * @param node points to the root of the tree ('.internet')
458 * @param ident_len the length of the supplied object identifier
459 * @param ident points to the array of sub identifiers
460 * @param np points to the found object instance (rerurn)
461 * @return pointer to the requested parent (!) node if success, NULL otherwise
464 snmp_search_tree(struct mib_node
*node
, u8_t ident_len
, s32_t
*ident
, struct snmp_name_ptr
*np
)
466 u8_t node_type
, ext_level
;
469 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("node==%p *ident==%"S32_F
"\n",(void*)node
,*ident
));
472 node_type
= node
->node_type
;
473 if ((node_type
== MIB_NODE_AR
) || (node_type
== MIB_NODE_RA
))
475 struct mib_array_node
*an
;
480 /* array node (internal ROM or RAM, fixed length) */
481 an
= (struct mib_array_node
*)node
;
483 while ((i
< an
->maxlength
) && (an
->objid
[i
] != *ident
))
487 if (i
< an
->maxlength
)
489 /* found it, if available proceed to child, otherwise inspect leaf */
490 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("an->objid[%"U16_F
"]==%"S32_F
" *ident==%"S32_F
"\n",i
,an
->objid
[i
],*ident
));
491 if (an
->nptr
[i
] == NULL
)
493 /* a scalar leaf OR table,
494 inspect remaining instance number / table index */
495 np
->ident_len
= ident_len
;
497 return (struct mib_node
*)an
;
501 /* follow next child pointer */
509 /* search failed, identifier mismatch (nosuchname) */
510 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("an search failed *ident==%"S32_F
"\n",*ident
));
516 /* search failed, short object identifier (nosuchname) */
517 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("an search failed, short object identifier\n"));
521 else if(node_type
== MIB_NODE_LR
)
523 struct mib_list_rootnode
*lrn
;
524 struct mib_list_node
*ln
;
528 /* list root node (internal 'RAM', variable length) */
529 lrn
= (struct mib_list_rootnode
*)node
;
531 /* iterate over list, head to tail */
532 while ((ln
!= NULL
) && (ln
->objid
!= *ident
))
538 /* found it, proceed to child */;
539 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("ln->objid==%"S32_F
" *ident==%"S32_F
"\n",ln
->objid
,*ident
));
540 if (ln
->nptr
== NULL
)
542 np
->ident_len
= ident_len
;
544 return (struct mib_node
*)lrn
;
548 /* follow next child pointer */
557 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("ln search failed *ident==%"S32_F
"\n",*ident
));
563 /* search failed, short object identifier (nosuchname) */
564 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("ln search failed, short object identifier\n"));
568 else if(node_type
== MIB_NODE_EX
)
570 struct mib_external_node
*en
;
575 /* external node (addressing and access via functions) */
576 en
= (struct mib_external_node
*)node
;
579 len
= en
->level_length(en
->addr_inf
,ext_level
);
580 while ((i
< len
) && (en
->ident_cmp(en
->addr_inf
,ext_level
,i
,*ident
) != 0))
588 en
->get_objid(en
->addr_inf
,ext_level
,i
,&debug_id
);
589 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("en->objid==%"S32_F
" *ident==%"S32_F
"\n",debug_id
,*ident
));
590 if ((ext_level
+ 1) == en
->tree_levels
)
592 np
->ident_len
= ident_len
;
594 return (struct mib_node
*)en
;
598 /* found it, proceed to child */
607 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("en search failed *ident==%"S32_F
"\n",*ident
));
613 /* search failed, short object identifier (nosuchname) */
614 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("en search failed, short object identifier\n"));
618 else if (node_type
== MIB_NODE_SC
)
622 sn
= (mib_scalar_node
*)node
;
623 if ((ident_len
== 1) && (*ident
== 0))
625 np
->ident_len
= ident_len
;
627 return (struct mib_node
*)sn
;
631 /* search failed, short object identifier (nosuchname) */
632 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("search failed, invalid object identifier length\n"));
638 /* unknown node_type */
639 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("search failed node_type %"U16_F
" unkown\n",(u16_t
)node_type
));
643 /* done, found nothing */
644 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("search failed node==%p\n",(void*)node
));
649 * Test table for presence of at least one table entry.
652 empty_table(struct mib_node
*node
)
659 node_type
= node
->node_type
;
660 if (node_type
== MIB_NODE_LR
)
662 struct mib_list_rootnode
*lrn
;
663 lrn
= (struct mib_list_rootnode
*)node
;
664 if ((lrn
->count
== 0) || (lrn
->head
== NULL
))
669 else if ((node_type
== MIB_NODE_AR
) || (node_type
== MIB_NODE_RA
))
671 struct mib_array_node
*an
;
672 an
= (struct mib_array_node
*)node
;
673 if ((an
->maxlength
== 0) || (an
->nptr
== NULL
))
678 else if (node_type
== MIB_NODE_EX
)
680 struct mib_external_node
*en
;
681 en
= (struct mib_external_node
*)node
;
682 if (en
->tree_levels
== 0)
695 snmp_expand_tree(struct mib_node
*node
, u8_t ident_len
, s32_t
*ident
, struct snmp_obj_id
*oidret
)
697 u8_t node_type
, ext_level
, climb_tree
;
700 /* reset node stack */
705 node_type
= node
->node_type
;
706 if ((node_type
== MIB_NODE_AR
) || (node_type
== MIB_NODE_RA
))
708 struct mib_array_node
*an
;
711 /* array node (internal ROM or RAM, fixed length) */
712 an
= (struct mib_array_node
*)node
;
716 while ((i
< an
->maxlength
) && (an
->objid
[i
] < *ident
))
720 if (i
< an
->maxlength
)
722 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("an->objid[%"U16_F
"]==%"S32_F
" *ident==%"S32_F
"\n",i
,an
->objid
[i
],*ident
));
723 /* add identifier to oidret */
724 oidret
->id
[oidret
->len
] = an
->objid
[i
];
727 if (an
->nptr
[i
] == NULL
)
729 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("leaf node\n"));
730 /* leaf node (e.g. in a fixed size table) */
731 if (an
->objid
[i
] > *ident
)
733 return (struct mib_node
*)an
;
735 else if ((i
+ 1) < an
->maxlength
)
737 /* an->objid[i] == *ident */
739 oidret
->id
[oidret
->len
] = an
->objid
[i
+ 1];
741 return (struct mib_node
*)an
;
745 /* (i + 1) == an->maxlength */
755 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("non-leaf node\n"));
756 /* non-leaf, store right child ptr and id */
758 while ((j
< an
->maxlength
) && (empty_table(an
->nptr
[j
])))
762 if (j
< an
->maxlength
)
764 cur_node
.r_ptr
= an
->nptr
[j
];
765 cur_node
.r_id
= an
->objid
[j
];
770 cur_node
.r_ptr
= NULL
;
772 push_node(&cur_node
);
773 if (an
->objid
[i
] == *ident
)
780 /* an->objid[i] < *ident */
783 /* follow next child pointer */
789 /* i == an->maxlength */
796 /* ident_len == 0, complete with leftmost '.thing' */
798 while ((j
< an
->maxlength
) && empty_table(an
->nptr
[j
]))
802 if (j
< an
->maxlength
)
804 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("left an->objid[j]==%"S32_F
"\n",an
->objid
[j
]));
805 oidret
->id
[oidret
->len
] = an
->objid
[j
];
807 if (an
->nptr
[j
] == NULL
)
810 return (struct mib_node
*)an
;
814 /* no leaf, continue */
820 /* j == an->maxlength */
825 else if(node_type
== MIB_NODE_LR
)
827 struct mib_list_rootnode
*lrn
;
828 struct mib_list_node
*ln
;
830 /* list root node (internal 'RAM', variable length) */
831 lrn
= (struct mib_list_rootnode
*)node
;
835 /* iterate over list, head to tail */
836 while ((ln
!= NULL
) && (ln
->objid
< *ident
))
842 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("ln->objid==%"S32_F
" *ident==%"S32_F
"\n",ln
->objid
,*ident
));
843 oidret
->id
[oidret
->len
] = ln
->objid
;
845 if (ln
->nptr
== NULL
)
848 if (ln
->objid
> *ident
)
850 return (struct mib_node
*)lrn
;
852 else if (ln
->next
!= NULL
)
854 /* ln->objid == *ident */
856 oidret
->id
[oidret
->len
] = ln
->next
->objid
;
858 return (struct mib_node
*)lrn
;
862 /* ln->next == NULL */
869 struct mib_list_node
*jn
;
872 /* non-leaf, store right child ptr and id */
874 while ((jn
!= NULL
) && empty_table(jn
->nptr
))
880 cur_node
.r_ptr
= jn
->nptr
;
881 cur_node
.r_id
= jn
->objid
;
886 cur_node
.r_ptr
= NULL
;
888 push_node(&cur_node
);
889 if (ln
->objid
== *ident
)
896 /* ln->objid < *ident */
899 /* follow next child pointer */
912 struct mib_list_node
*jn
;
913 /* ident_len == 0, complete with leftmost '.thing' */
915 while ((jn
!= NULL
) && empty_table(jn
->nptr
))
921 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("left jn->objid==%"S32_F
"\n",jn
->objid
));
922 oidret
->id
[oidret
->len
] = jn
->objid
;
924 if (jn
->nptr
== NULL
)
927 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("jn->nptr == NULL\n"));
928 return (struct mib_node
*)lrn
;
932 /* no leaf, continue */
943 else if(node_type
== MIB_NODE_EX
)
945 struct mib_external_node
*en
;
948 /* external node (addressing and access via functions) */
949 en
= (struct mib_external_node
*)node
;
955 len
= en
->level_length(en
->addr_inf
,ext_level
);
956 while ((i
< len
) && (en
->ident_cmp(en
->addr_inf
,ext_level
,i
,*ident
) < 0))
962 /* add identifier to oidret */
963 en
->get_objid(en
->addr_inf
,ext_level
,i
,&ex_id
);
964 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("en->objid[%"U16_F
"]==%"S32_F
" *ident==%"S32_F
"\n",i
,ex_id
,*ident
));
965 oidret
->id
[oidret
->len
] = ex_id
;
968 if ((ext_level
+ 1) == en
->tree_levels
)
970 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("leaf node\n"));
974 return (struct mib_node
*)en
;
976 else if ((i
+ 1) < len
)
978 /* ex_id == *ident */
979 en
->get_objid(en
->addr_inf
,ext_level
,i
+ 1,&ex_id
);
981 oidret
->id
[oidret
->len
] = ex_id
;
983 return (struct mib_node
*)en
;
997 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("non-leaf node\n"));
998 /* non-leaf, store right child ptr and id */
1002 /* right node is the current external node */
1003 cur_node
.r_ptr
= node
;
1004 en
->get_objid(en
->addr_inf
,ext_level
,j
,&cur_node
.r_id
);
1005 cur_node
.r_nl
= ext_level
+ 1;
1009 cur_node
.r_ptr
= NULL
;
1011 push_node(&cur_node
);
1012 if (en
->ident_cmp(en
->addr_inf
,ext_level
,i
,*ident
) == 0)
1019 /* external id < *ident */
1022 /* proceed to child */
1028 /* i == len (en->level_len()) */
1034 /* ident_len == 0, complete with leftmost '.thing' */
1035 en
->get_objid(en
->addr_inf
,ext_level
,0,&ex_id
);
1036 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("left en->objid==%"S32_F
"\n",ex_id
));
1037 oidret
->id
[oidret
->len
] = ex_id
;
1039 if ((ext_level
+ 1) == en
->tree_levels
)
1042 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("(ext_level + 1) == en->tree_levels\n"));
1043 return (struct mib_node
*)en
;
1047 /* no leaf, proceed to child */
1052 else if(node_type
== MIB_NODE_SC
)
1054 mib_scalar_node
*sn
;
1057 sn
= (mib_scalar_node
*)node
;
1065 /* ident_len == 0, complete object identifier */
1066 oidret
->id
[oidret
->len
] = 0;
1069 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("completed scalar leaf\n"));
1070 return (struct mib_node
*)sn
;
1075 /* unknown/unhandled node_type */
1076 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("expand failed node_type %"U16_F
" unkown\n",(u16_t
)node_type
));
1084 /* find right child ptr */
1088 while ((node_stack_cnt
> 0) && (child
.r_ptr
== NULL
))
1091 /* trim returned oid */
1094 if (child
.r_ptr
!= NULL
)
1096 /* incoming ident is useless beyond this point */
1098 oidret
->id
[oidret
->len
] = child
.r_id
;
1101 ext_level
= child
.r_nl
;
1105 /* tree ends here ... */
1106 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("expand failed, tree ends here\n"));
1111 /* done, found nothing */
1112 LWIP_DEBUGF(SNMP_MIB_DEBUG
,("expand failed node==%p\n",(void*)node
));
1117 * Test object identifier for the iso.org.dod.internet prefix.
1119 * @param ident_len the length of the supplied object identifier
1120 * @param ident points to the array of sub identifiers
1121 * @return 1 if it matches, 0 otherwise
1124 snmp_iso_prefix_tst(u8_t ident_len
, s32_t
*ident
)
1126 if ((ident_len
> 3) &&
1127 (ident
[0] == 1) && (ident
[1] == 3) &&
1128 (ident
[2] == 6) && (ident
[3] == 1))
1139 * Expands object identifier to the iso.org.dod.internet
1140 * prefix for use in getnext operation.
1142 * @param ident_len the length of the supplied object identifier
1143 * @param ident points to the array of sub identifiers
1144 * @param oidret points to returned expanded object identifier
1145 * @return 1 if it matches, 0 otherwise
1147 * @note ident_len 0 is allowed, expanding to the first known object id!!
1150 snmp_iso_prefix_expand(u8_t ident_len
, s32_t
*ident
, struct snmp_obj_id
*oidret
)
1152 const s32_t
*prefix_ptr
;
1157 prefix_ptr
= &prefix
[0];
1158 ret_ptr
= &oidret
->id
[0];
1159 ident_len
= ((ident_len
< 4)?ident_len
:4);
1160 while ((i
< ident_len
) && ((*ident
) <= (*prefix_ptr
)))
1162 *ret_ptr
++ = *prefix_ptr
++;
1168 /* match, complete missing bits */
1171 *ret_ptr
++ = *prefix_ptr
++;
1179 /* i != ident_len */
1184 #endif /* LWIP_SNMP */