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#include <net-snmp/net-snmp-config.h>
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#include <net-snmp/net-snmp-includes.h>
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/** @defgroup oid_stash Store and retrieve data referenced by an OID.
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This is essentially a way of storing data associated with a given
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OID. It stores a bunch of data pointers within a memory tree that
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allows fairly efficient lookups with a heavily populated tree.
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* xxx-rks: when you have some spare time:
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* b) basically, everything currently creates one node per sub-oid,
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* which is less than optimal. add code to create nodes with the
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* longest possible OID per node, and split nodes when necessary
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* c) If you are feeling really ambitious, also merge split nodes if
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* possible on a delete.
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* xxx-wes: uh, right, like I *ever* have that much time.
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/***************************************************************************
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***************************************************************************/
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* Create an netsnmp_oid_stash node
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* @param mysize the size of the child pointer array
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* @return NULL on error, otherwise the newly allocated node
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netsnmp_oid_stash_node *
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netsnmp_oid_stash_create_sized_node(size_t mysize)
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netsnmp_oid_stash_node *ret;
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ret = SNMP_MALLOC_TYPEDEF(netsnmp_oid_stash_node);
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ret->children = calloc(mysize, sizeof(netsnmp_oid_stash_node *));
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ret->children_size = mysize;
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/** Creates a netsnmp_oid_stash_node.
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* Assumes you want the default OID_STASH_CHILDREN_SIZE hash size for the node.
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* @return NULL on error, otherwise the newly allocated node
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NETSNMP_INLINE netsnmp_oid_stash_node *
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netsnmp_oid_stash_create_node(void)
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return netsnmp_oid_stash_create_sized_node(OID_STASH_CHILDREN_SIZE);
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/** adds data to the stash at a given oid.
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* @param root the top of the stash tree
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* @param lookup the oid index to store the data at.
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* @param lookup_len the length of the lookup oid.
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* @param mydata the data to store
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* @return SNMPERR_SUCCESS on success, SNMPERR_GENERR if data is
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already there, SNMPERR_MALLOC on malloc failures or if arguments
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passed in with NULL values.
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netsnmp_oid_stash_add_data(netsnmp_oid_stash_node **root,
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oid * lookup, size_t lookup_len, void *mydata)
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netsnmp_oid_stash_node *curnode, *tmpp, *loopp;
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if (!root || !lookup || lookup_len == 0)
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return SNMPERR_GENERR;
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*root = netsnmp_oid_stash_create_node();
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return SNMPERR_MALLOC;
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for (curnode = *root, i = 0; i < lookup_len; i++) {
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tmpp = curnode->children[lookup[i] % curnode->children_size];
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* no child in array at all
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tmpp = curnode->children[lookup[i] % curnode->children_size] =
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netsnmp_oid_stash_create_node();
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tmpp->value = lookup[i];
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tmpp->parent = curnode;
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for (loopp = tmpp; loopp; loopp = loopp->next_sibling) {
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if (loopp->value == lookup[i])
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* none exists. Create it
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loopp = netsnmp_oid_stash_create_node();
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loopp->value = lookup[i];
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loopp->next_sibling = tmpp;
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loopp->parent = curnode;
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tmpp->prev_sibling = loopp;
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curnode->children[lookup[i] % curnode->children_size] =
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* tmpp now points to the proper node
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* tmpp now points to the exact match
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if (curnode->thedata)
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return SNMPERR_GENERR;
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return SNMPERR_GENERR;
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tmpp->thedata = mydata;
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return SNMPERR_SUCCESS;
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/** returns a node associated with a given OID.
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* @param root the top of the stash tree
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* @param lookup the oid to look up a node for.
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* @param lookup_len the length of the lookup oid
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netsnmp_oid_stash_node *
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netsnmp_oid_stash_get_node(netsnmp_oid_stash_node *root,
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oid * lookup, size_t lookup_len)
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netsnmp_oid_stash_node *curnode, *tmpp, *loopp;
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for (curnode = root, i = 0; i < lookup_len; i++) {
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tmpp = curnode->children[lookup[i] % curnode->children_size];
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for (loopp = tmpp; loopp; loopp = loopp->next_sibling) {
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if (loopp->value == lookup[i])
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/** returns the next node associated with a given OID. INCOMPLETE.
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This is equivelent to a GETNEXT operation.
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* @param root the top of the stash tree
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* @param lookup the oid to look up a node for.
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* @param lookup_len the length of the lookup oid
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netsnmp_oid_stash_node *
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netsnmp_oid_stash_getnext_node(netsnmp_oid_stash_node *root,
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oid * lookup, size_t lookup_len)
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netsnmp_oid_stash_node *curnode, *tmpp, *loopp;
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unsigned int i, j, bigger_than = 0, do_bigger = 0;
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/* get closest matching node */
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for (curnode = root, i = 0; i < lookup_len; i++) {
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tmpp = curnode->children[lookup[i] % curnode->children_size];
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for (loopp = tmpp; loopp; loopp = loopp->next_sibling) {
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if (loopp->value == lookup[i])
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/* find the *next* node lexographically greater */
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return NULL; /* ack! */
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if (i+1 < lookup_len) {
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bigger_than = lookup[i+1];
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/* check the children first */
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/* next child must be (next) greater than our next search node */
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/* XXX: should start this loop at best_nums[i]%... and wrap */
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for(j = 0; j < curnode->children_size; j++) {
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for (loopp = curnode->children[j];
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loopp; loopp = loopp->next_sibling) {
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if ((!do_bigger || loopp->value > bigger_than) &&
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(!tmpp || tmpp->value > loopp->value)) {
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/* XXX: can do better and include min_nums[i] */
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if (tmpp->value <= curnode->children_size-1) {
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/* best we can do. */
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if (tmpp && tmpp->thedata)
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/* found a node with data. Go with it. */
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/* found a child node without data, maybe find a grandchild? */
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/* no respectable children (the bums), we'll have to go up.
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But to do so, they must be better than our current best_num + 1.
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bigger_than = curnode->value;
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curnode = curnode->parent;
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/* fell off the top */
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/** returns a data pointer associated with a given OID.
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This is equivelent to netsnmp_oid_stash_get_node, but returns only
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the data not the entire node.
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* @param root the top of the stash
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* @param oid the oid to search for
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* @param the length of the search oid.
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netsnmp_oid_stash_get_data(netsnmp_oid_stash_node *root,
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oid * lookup, size_t lookup_len)
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netsnmp_oid_stash_node *ret;
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ret = netsnmp_oid_stash_get_node(root, lookup, lookup_len);
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/** a wrapper around netsnmp_oid_stash_store for use with a snmp_alarm.
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* when calling snmp_alarm, you can list this as a callback. The
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* clientarg should be a pointer to a netsnmp_oid_stash_save_info
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* pointer. It can also be called directly, of course. The last
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* argument (clientarg) is the only one that is used. The rest are
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* ignored by the function.
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* @param clientarg A pointer to a netsnmp_oid_stash_save_info structure.
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netsnmp_oid_stash_store_all(int majorID, int minorID,
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void *serverarg, void *clientarg) {
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oid oidbase[MAX_OID_LEN];
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netsnmp_oid_stash_save_info *sinfo;
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return SNMP_ERR_NOERROR;
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netsnmp_oid_stash_store(*(sinfo->root), sinfo->token, sinfo->dumpfn,
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return SNMP_ERR_NOERROR;
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/** stores data in a starsh tree to peristent storage.
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This function can be called to save all data in a stash tree to
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Net-SNMP's percent storage. Make sure you register a parsing
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function with the read_config system to re-incorperate your saved
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data into future trees.
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@param root the top of the stash to store.
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@param tokenname the file token name to save in (passing "snmpd" will
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save things into snmpd.conf).
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@param dumpfn A function which can dump the data stored at a particular
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node into a char buffer.
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@param curoid must be a pointer to a OID array of length MAX_OID_LEN.
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@param curoid_len must be 0 for the top level call.
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netsnmp_oid_stash_store(netsnmp_oid_stash_node *root,
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const char *tokenname, NetSNMPStashDump *dumpfn,
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oid *curoid, size_t curoid_len) {
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char buf[SNMP_MAXBUF];
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netsnmp_oid_stash_node *tmpp;
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char *appname = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
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NETSNMP_DS_LIB_APPTYPE);
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if (!tokenname || !root || !curoid || !dumpfn)
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for (i = 0; i < (int)root->children_size; i++) {
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if (root->children[i]) {
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for (tmpp = root->children[i]; tmpp; tmpp = tmpp->next_sibling) {
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curoid[curoid_len] = tmpp->value;
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snprintf(buf, sizeof(buf), "%s ", tokenname);
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cp = read_config_save_objid(buf+strlen(buf), curoid,
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if ((*dumpfn)(cp, sizeof(buf) - strlen(buf),
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tmpp->thedata, tmpp))
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read_config_store(appname, buf);
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netsnmp_oid_stash_store(tmpp, tokenname, dumpfn,
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curoid, curoid_len+1);
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/** For debugging: dump the netsnmp_oid_stash tree to stdout
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@param root The top of the tree
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@param prefix a character string prefix printed to the beginning of each line.
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oid_stash_dump(netsnmp_oid_stash_node *root, char *prefix)
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char myprefix[MAX_OID_LEN * 4];
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netsnmp_oid_stash_node *tmpp;
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int prefix_len = strlen(prefix) + 1; /* actually it's +2 */
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memset(myprefix, ' ', MAX_OID_LEN * 4);
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myprefix[prefix_len] = '\0';
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for (i = 0; i < root->children_size; i++) {
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if (root->children[i]) {
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for (tmpp = root->children[i]; tmpp; tmpp = tmpp->next_sibling) {
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printf("%s%ld@%d: %s\n", prefix, tmpp->value, i,
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(tmpp->thedata) ? "DATA" : "");
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oid_stash_dump(tmpp, myprefix);
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/** Frees the contents of a netsnmp_oid_stash tree.
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@param root the top of the tree (or branch to be freed)
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@param freefn The function to be called on each data (void *)
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pointer. If left NULL the system free() function will be called
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netsnmp_oid_stash_free(netsnmp_oid_stash_node **root,
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NetSNMPStashFreeNode *freefn) {
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netsnmp_oid_stash_node *curnode, *tmpp;
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/* loop through all our children and free each node */
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for (i = 0; i < (*root)->children_size; i++) {
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if ((*root)->children[i]) {
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for(tmpp = (*root)->children[i]; tmpp; tmpp = curnode) {
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(*freefn)(tmpp->thedata);
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curnode = tmpp->next_sibling;
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netsnmp_oid_stash_free(&tmpp, freefn);
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free((*root)->children);
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netsnmp_oid_stash_no_free(void *bogus)
added
removed
snmplib/oid_stash.c
