/* GETNEXT request search, depth-first traversal in mib-tree, find the closest next oid. */
void
mib_tree_search_next(struct mib_view *view, const oid_t *orig_oid, uint32_t orig_id_len, struct oid_search_res *ret_oid)
{
oid_t *oid;
uint32_t id_len;
struct node_backlog nbl, *p_nbl;
struct node_backlog nbl_stk[MIB_OID_MAX_LEN];
struct node_backlog *stk_top, *stk_buttom;
struct mib_node *node;
struct mib_group_node *gn;
struct mib_instance_node *in;
/* 'immediate' is the search state indicator.
* 0 is to get the matched instance according to the given oid;
* 1 is to get the immediate first instance regardless of the given oid. */
uint8_t immediate = 0;
assert(view != NULL && orig_oid != NULL && ret_oid != NULL);
/* Access control */
if (oid_cover(view->oid, view->id_len, orig_oid, orig_id_len) > 0) {
/* In the range of view, search the root node at view oid */
ret_oid->request = MIB_REQ_GET;
node = mib_tree_search(view, view->oid, view->id_len, ret_oid);
assert(node != NULL);
ret_oid->request = MIB_REQ_GETNEXT;
/* Duplicate the given oid */
oid_cpy(ret_oid->oid, orig_oid, orig_id_len);
ret_oid->id_len = orig_id_len;
if (ret_oid->id_len > ret_oid->inst_id - ret_oid->oid) {
/* Given oid is longer than the search result's, we need to search according to the given oid */
immediate = 0;
} else {
/* Otherwise, ignore the given oid */
immediate = 1;
}
} else {
/* Out of range of view */
if (oid_cmp(orig_oid, orig_id_len, view->oid, view->id_len) < 0) {
/* Given oid is ahead of view, search the root node at view oid */
ret_oid->request = MIB_REQ_GET;
node = mib_tree_search(view, view->oid, view->id_len, ret_oid);
assert(node != NULL);
ret_oid->request = MIB_REQ_GETNEXT;
/* Set the search mode according to node type */
if (node->type == MIB_OBJ_GROUP) {
immediate = 1;
} else {
immediate = 0;
}
} else {
/* END_OF_MIB_VIEW */
node = NULL;
ret_oid->oid = oid_dup(view->oid, view->id_len);
ret_oid->id_len = view->id_len;
}
}
/* Init something */
p_nbl = NULL;
stk_top = stk_buttom = nbl_stk;
ret_oid->err_stat = 0;
oid = ret_oid->inst_id;
id_len = ret_oid->id_len - (oid - ret_oid->oid);
for (; ;) {
if (node != NULL) {
switch (node->type) {
case MIB_OBJ_GROUP:
gn = (struct mib_group_node *)node;
if (immediate) {
/* Fetch the immediate instance node. */
int i;
if (p_nbl != NULL) {
/* Fetch the sub-id next to the pop-up backlogged one. */
i = p_nbl->n_idx;
p_nbl = NULL;
} else {
/* Fetch the first sub-id. */
i = 0;
}
if (i + 1 >= gn->sub_id_cnt) {
/* Last sub-id, mark NULL and -1. */
nbl.node = NULL;
nbl.n_idx = -1;
} else {
nbl.node = node;
nbl.n_idx = i + 1;
}
/* Backlog the current node and move on. */
nbl_push(&nbl, &stk_top, &stk_buttom);
*oid++ = gn->sub_id[i];
node = gn->sub_ptr[i];
} else {
/* Search the match sub-id */
int index = oid_binary_search(gn->sub_id, gn->sub_id_cnt, *oid);
int i = index;
if (index < 0) {
/* Not found, switch to the immediate search mode */
immediate = 1;
/* Reverse the sign to locate the right position. */
i = -i - 1;
if (i == gn->sub_id_cnt) {
/* All sub-ids are greater than the target;
* Backtrack and fetch the next one. */
break;
} else if (i == 0) {
/* 1. All sub-ids are less than the target;
* 2. No sub-id in this group node;
* Just switch to the immediate search mode */
continue;
} /* else {
Target is between the two sub-ids and [i] is the next one,
switch to immediate mode and move on.
} */
}
/* Sub-id found is greater or just equal to the target,
* Anyway, record the next node and push it into stack. */
if (i + 1 >= gn->sub_id_cnt) {
/* Last sub-id, mark NULL and -1. */
nbl.node = NULL;
nbl.n_idx = -1;
} else {
nbl.node = node;
nbl.n_idx = i + 1;
}
/* Backlog the current node and move on. */
nbl_push(&nbl, &stk_top, &stk_buttom);
*oid++ = gn->sub_id[i];
node = gn->sub_ptr[i];
if (--id_len == 0 && node->type == MIB_OBJ_GROUP) {
/* When oid length is decreased to zero, switch to the immediate mode */
immediate = 1;
}
}
continue; /* Go on loop */
case MIB_OBJ_INSTANCE:
in = (struct mib_instance_node *)node;
if (immediate || id_len == 0) {
/* Fetch the first instance variable */
ret_oid->inst_id_len = 0;
} else {
/* Search the closest instance whose oid is greater than the target */
ret_oid->inst_id_len = id_len;
}
/* Find instance variable through lua handler function */
ret_oid->inst_id = oid;
ret_oid->callback = in->callback;
ret_oid->err_stat = mib_instance_search(ret_oid);
if (MIB_TAG_VALID(tag(&ret_oid->var))) {
ret_oid->id_len = oid - ret_oid->oid + ret_oid->inst_id_len;
assert(ret_oid->id_len <= MIB_OID_MAX_LEN);
if (!oid_cover(view->oid, view->id_len, ret_oid->oid, ret_oid->id_len)) {
/* End of mib view */
break;
}
return;
} else {
/* Instance not found */
break;
}
default:
assert(0);
}
}
/* Backtracking condition:
* 1. No greater sub-id in group node;
* 2. Seek the immediate closest instance node;
* 3. Node not exists(node == NULL).
*/
p_nbl = nbl_pop(&stk_top, &stk_buttom);
if (p_nbl == NULL) {
/* End of traversal. */
oid_cpy(ret_oid->oid, orig_oid, orig_id_len);
ret_oid->id_len = orig_id_len;
ret_oid->inst_id = NULL;
ret_oid->inst_id_len = 0;
ret_oid->err_stat = 0;
tag(&ret_oid->var) = ASN1_TAG_END_OF_MIB_VIEW;
return;
}
oid--; /* OID length is ignored once backtracking. */
node = p_nbl->node;
immediate = 1; /* Switch to the immediate search mode. */
}
}
/* GETNEXT request search, depth-first traversal in mib-tree, find the closest next oid. */
struct mib_node *
mib_tree_search_next(const oid_t *orig_oid, uint32_t orig_id_len, struct oid_search_res *ret_oid)
{
oid_t *oid;
uint32_t id_len;
uint8_t immediate; /* This is the search state indicator */
struct node_backlog nbl, *p_nbl;
struct node_backlog nbl_stk[MIB_OID_MAX_LEN];
struct node_backlog *stk_top, *stk_buttom;
struct oid_search_res tmp_res;
struct mib_node *node;
struct mib_group_node *gn;
struct mib_instance_node *in;
/* Check dummy root oid prefix */
if (orig_id_len > root_oid_len) {
immediate = 0; /* 0 is to search the first match node in mib tree. */
ret_oid->oid = oid_dup(orig_oid, orig_id_len);
ret_oid->id_len = orig_id_len;
if (oid_cmp(orig_oid, root_oid_len, root_oid, root_oid_len) > 0) {
/* END_OF_MIB_VIEW */
node = NULL;
} else {
node = mib_tree_search(root_oid, root_oid_len, &tmp_res);
free(tmp_res.oid);
}
} else {
immediate = 1; /* 1 is to get the immediate closest instance */
ret_oid->oid = oid_dup(root_oid, root_oid_len);
ret_oid->id_len = root_oid_len;
if (oid_cmp(orig_oid, orig_id_len, root_oid, root_oid_len) > 0) {
/* END_OF_MIB_VIEW */
node = NULL;
} else {
node = mib_tree_search(root_oid, root_oid_len, &tmp_res);
free(tmp_res.oid);
}
}
/* Init something */
p_nbl = NULL;
stk_top = stk_buttom = nbl_stk;
oid = ret_oid->oid + root_oid_len;
id_len = ret_oid->id_len - root_oid_len;
ret_oid->inst_id = NULL;
ret_oid->inst_id_len = 0;
ret_oid->exist_state = 0;
for (; ;) {
if (node != NULL)
switch (node->type) {
case MIB_OBJ_GROUP:
gn = (struct mib_group_node *)node;
if (immediate) {
/* Fetch the immediate instance node. */
int i;
if (p_nbl != NULL) {
/* Fetch the sub-id next to the pop-up backlogged one. */
i = p_nbl->n_idx;
p_nbl = NULL;
} else {
/* Fetch the first sub-id. */
i = 0;
}
if (i + 1 >= gn->sub_id_cnt) {
/* Last sub-id, mark NULL and -1. */
nbl.node = NULL;
nbl.n_idx = -1;
} else {
nbl.node = node;
nbl.n_idx = i + 1;
}
/* Backlog the current node and move on. */
nbl_push(&nbl, &stk_top, &stk_buttom);
*oid++ = gn->sub_id[i];
node = gn->sub_ptr[i];
} else {
/* Search the match sub-id */
int index = oid_binary_search(gn->sub_id, gn->sub_id_cnt, *oid);
int i = index;
if (index < 0) {
/* Not found, switch to the immediate search mode */
immediate = 1;
/* Reverse the sign to locate the right position. */
i = -i - 1;
if (i == gn->sub_id_cnt) {
/* All sub-ids are greater than the target;
* Backtrack and fetch the next one. */
break;
} else if (i == 0) {
/* 1. All sub-ids are less than the target;
* 2. No sub-id in this group node;
* Just switch to the immediate search mode */
continue;
} /* else {
Target is between the two sub-ids and [i] is the next one,
switch to immediate mode and move on.
} */
}
/* Sub-id found is greater or just equal to the target,
* Anyway, record the next node and push it into stack. */
if (i + 1 >= gn->sub_id_cnt) {
/* Last sub-id, mark NULL and -1. */
nbl.node = NULL;
nbl.n_idx = -1;
} else {
nbl.node = node;
nbl.n_idx = i + 1;
}
/* Backlog the current node and move on. */
nbl_push(&nbl, &stk_top, &stk_buttom);
*oid++ = gn->sub_id[i];
node = gn->sub_ptr[i];
if (--id_len == 0 && node->type == MIB_OBJ_GROUP) {
/* When oid length is decreased to zero, switch to the immediate mode */
immediate = 1;
}
}
continue; /* Go on loop */
case MIB_OBJ_INSTANCE:
in = (struct mib_instance_node *)node;
if (immediate || id_len == 0) {
/* Fetch the first instance variable */
ret_oid->inst_id_len = 0;
} else {
/* Search the closest instance whose oid is greater than the target */
ret_oid->inst_id_len = id_len;
}
/* Find instance variable through lua handler function */
ret_oid->inst_id = oid;
ret_oid->callback = in->callback;
ret_oid->exist_state = mib_instance_search(ret_oid);
if (ret_oid->exist_state == 0 || ret_oid->exist_state < ASN1_TAG_NO_SUCH_OBJ) {
ret_oid->id_len = oid - ret_oid->oid + ret_oid->inst_id_len;
assert(ret_oid->id_len <= MIB_OID_MAX_LEN);
return node;
} else {
/* Instance not found */
break;
}
default:
assert(0);
}
/* Backtracking condition:
* 1. No greater sub-id in group node;
* 2. Seek the immediate closest instance node;
* 3. Node not exists(node == NULL).
*/
p_nbl = nbl_pop(&stk_top, &stk_buttom);
if (p_nbl == NULL) {
/* End of traversal. */
oid_cpy(ret_oid->oid, orig_oid, orig_id_len);
ret_oid->id_len = orig_id_len;
ret_oid->inst_id = NULL;
ret_oid->inst_id_len = 0;
ret_oid->exist_state = ASN1_TAG_END_OF_MIB_VIEW;
return (struct mib_node *)&mib_dummy_node;
}
oid--; /* OID length is ignored once backtracking. */
node = p_nbl->node;
immediate = 1; /* Switch to the immediate search mode. */
}
assert(0);
return node;
}
