#include <net-snmp/net-snmp-config.h>

#include <string.h>

#include <stdlib.h>

#include <sys/types.h>

#include <net-snmp/net-snmp-features.h>

#include <net-snmp/net-snmp-includes.h>

netsnmp_feature_child_of(oid_stash_all, libnetsnmp);

netsnmp_feature_child_of(oid_stash, oid_stash_all);

netsnmp_feature_child_of(oid_stash_no_free, oid_stash_all);

#ifndef NETSNMP_FEATURE_REMOVE_OID_STASH

/** @defgroup oid_stash Store and retrieve data referenced by an OID.

    This is essentially a way of storing data associated with a given

    OID.  It stores a bunch of data pointers within a memory tree that

    allows fairly efficient lookups with a heavily populated tree.

    @ingroup library

    @{

*/

/*

 * xxx-rks: when you have some spare time:

 *

 * b) basically, everything currently creates one node per sub-oid,

 *    which is less than optimal. add code to create nodes with the

 *    longest possible OID per node, and split nodes when necessary

 *    during adds.

 *

 * c) If you are feeling really ambitious, also merge split nodes if

 *    possible on a delete.

 *

 * xxx-wes: uh, right, like I *ever* have that much time.

 *

 */

/***************************************************************************

 *

 *

 ***************************************************************************/

/**

 * Create an netsnmp_oid_stash node

 *

 * @param mysize  the size of the child pointer array

 *

 * @return NULL on error, otherwise the newly allocated node

 */

netsnmp_oid_stash_node *

netsnmp_oid_stash_create_sized_node(size_t mysize)

{

    netsnmp_oid_stash_node *ret;

    ret = SNMP_MALLOC_TYPEDEF(netsnmp_oid_stash_node);

    if (!ret)

        return NULL;

    ret->children = calloc(mysize, sizeof(netsnmp_oid_stash_node *));

    if (!ret->children) {

        free(ret);

        return NULL;

    }

    ret->children_size = mysize;

    return ret;

}

/** Creates a netsnmp_oid_stash_node.

 * Assumes you want the default OID_STASH_CHILDREN_SIZE hash size for the node.

 * @return NULL on error, otherwise the newly allocated node

 */

NETSNMP_INLINE netsnmp_oid_stash_node *

netsnmp_oid_stash_create_node(void)

{

    return netsnmp_oid_stash_create_sized_node(OID_STASH_CHILDREN_SIZE);

}

netsnmp_feature_child_of(oid_stash_add_data, oid_stash_all);

#ifndef NETSNMP_FEATURE_REMOVE_OID_STASH_ADD_DATA

/** adds data to the stash at a given oid.

 * @param root the top of the stash tree

 * @param lookup the oid index to store the data at.

 * @param lookup_len the length of the lookup oid.

 * @param mydata the data to store

 * @return SNMPERR_SUCCESS on success, SNMPERR_GENERR if data is

   already there, SNMPERR_MALLOC on malloc failures or if arguments

   passed in with NULL values.

 */

int

netsnmp_oid_stash_add_data(netsnmp_oid_stash_node **root,

                           const oid * lookup, size_t lookup_len, void *mydata)

{

    netsnmp_oid_stash_node *curnode, *tmpp, *loopp;

    unsigned int    i;

    if (!root || !lookup || lookup_len == 0)

        return SNMPERR_GENERR;

    if (!*root) {

        *root = netsnmp_oid_stash_create_node();

        if (!*root)

            return SNMPERR_MALLOC;

    }

    DEBUGMSGTL(( "oid_stash", "stash_add_data "));

    DEBUGMSGOID(("oid_stash", lookup, lookup_len));

    DEBUGMSG((   "oid_stash", "\n"));

    tmpp = NULL;

    for (curnode = *root, i = 0; i < lookup_len; i++) {

        tmpp = curnode->children[lookup[i] % curnode->children_size];

        if (!tmpp) {

            /*

             * no child in array at all 

             */

            tmpp = curnode->children[lookup[i] % curnode->children_size] =

                netsnmp_oid_stash_create_node();

            tmpp->value = lookup[i];

            tmpp->parent = curnode;

        } else {

            for (loopp = tmpp; loopp; loopp = loopp->next_sibling) {

                if (loopp->value == lookup[i])

                    break;

            }

            if (loopp) {

                tmpp = loopp;

            } else {

                /*

                 * none exists.  Create it 

                 */

                loopp = netsnmp_oid_stash_create_node();

                loopp->value = lookup[i];

                loopp->next_sibling = tmpp;

                loopp->parent = curnode;

                tmpp->prev_sibling = loopp;

                curnode->children[lookup[i] % curnode->children_size] =

                    loopp;

                tmpp = loopp;

            }

            /*

             * tmpp now points to the proper node 

             */

        }

        curnode = tmpp;

    }

    /*

     * tmpp now points to the exact match 

     */

    if (curnode->thedata)

        return SNMPERR_GENERR;

    if (NULL == tmpp)

        return SNMPERR_GENERR;

    tmpp->thedata = mydata;

    return SNMPERR_SUCCESS;

}

#endif /* NETSNMP_FEATURE_REMOVE_OID_STASH_ADD_DATA */

/** returns a node associated with a given OID.

 * @param root the top of the stash tree

 * @param lookup the oid to look up a node for.

 * @param lookup_len the length of the lookup oid

 */

netsnmp_oid_stash_node *

netsnmp_oid_stash_get_node(netsnmp_oid_stash_node *root,

                           const oid * lookup, size_t lookup_len)

{

    netsnmp_oid_stash_node *curnode, *tmpp, *loopp;

    unsigned int    i;

    if (!root)

        return NULL;

    tmpp = NULL;

    for (curnode = root, i = 0; i < lookup_len; i++) {

        tmpp = curnode->children[lookup[i] % curnode->children_size];

        if (!tmpp) {

            return NULL;

        } else {

            for (loopp = tmpp; loopp; loopp = loopp->next_sibling) {

                if (loopp->value == lookup[i])

                    break;

            }

            if (loopp) {

                tmpp = loopp;

            } else {

                return NULL;

            }

        }

        curnode = tmpp;

    }

    return tmpp;

}

/** returns the next node associated with a given OID. INCOMPLETE.

    This is equivalent to a GETNEXT operation.

 * @internal

 * @param root the top of the stash tree

 * @param lookup the oid to look up a node for.

 * @param lookup_len the length of the lookup oid

 */

netsnmp_feature_child_of(oid_stash_iterate, oid_stash_all);

#ifndef NETSNMP_FEATURE_REMOVE_OID_STASH_ITERATE

netsnmp_oid_stash_node *

netsnmp_oid_stash_getnext_node(netsnmp_oid_stash_node *root,

                               oid * lookup, size_t lookup_len)

{

    netsnmp_oid_stash_node *curnode, *tmpp, *loopp;

    unsigned int    i, j, bigger_than = 0, do_bigger = 0;

    if (!root)

        return NULL;

    tmpp = NULL;

    /* get closest matching node */

    for (curnode = root, i = 0; i < lookup_len; i++) {

        tmpp = curnode->children[lookup[i] % curnode->children_size];

        if (!tmpp) {

            break;

        } else {

            for (loopp = tmpp; loopp; loopp = loopp->next_sibling) {

                if (loopp->value == lookup[i])

                    break;

            }

            if (loopp) {

                tmpp = loopp;

            } else {

                break;

            }

        }

        curnode = tmpp;

    }

    /* find the *next* node lexographically greater */

    if (!curnode)

        return NULL; /* ack! */

    if (i+1 < lookup_len) {

        bigger_than = lookup[i+1];

        do_bigger = 1;

    }

    do {

        /* check the children first */

        tmpp = NULL;

        /* next child must be (next) greater than our next search node */

        /* XXX: should start this loop at best_nums[i]%... and wrap */

        for(j = 0; j < curnode->children_size; j++) {

            for (loopp = curnode->children[j];

                 loopp; loopp = loopp->next_sibling) {

                if ((!do_bigger || loopp->value > bigger_than) &&

                    (!tmpp || tmpp->value > loopp->value)) {

                    tmpp = loopp;

                    /* XXX: can do better and include min_nums[i] */

                    if (tmpp->value <= curnode->children_size-1) {

                        /* best we can do. */

                        goto done_this_loop;

                    }

                }

            }

        }

      done_this_loop:

        if (tmpp && tmpp->thedata)

            /* found a node with data.  Go with it. */

            return tmpp;

        if (tmpp) {

            /* found a child node without data, maybe find a grandchild? */

            do_bigger = 0;

            curnode = tmpp;

        } else {

            /* no respectable children (the bums), we'll have to go up.

               But to do so, they must be better than our current best_num + 1.

            */

            do_bigger = 1;

            bigger_than = curnode->value;

            curnode = curnode->parent;

        }

    } while (curnode);

    /* fell off the top */

    return NULL;

}

#endif /* NETSNMP_FEATURE_REMOVE_OID_STASH_ITERATE */

netsnmp_feature_child_of(oid_stash_get_data, oid_stash_all);

#ifndef NETSNMP_FEATURE_REMOVE_OID_STASH_GET_DATA

/** returns a data pointer associated with a given OID.

    This is equivalent to netsnmp_oid_stash_get_node, but returns only

    the data not the entire node.

 * @param root the top of the stash

 * @param lookup the oid to search for

 * @param lookup_len the length of the search oid.

 */

void           *

netsnmp_oid_stash_get_data(netsnmp_oid_stash_node *root,

                           const oid * lookup, size_t lookup_len)

{

    netsnmp_oid_stash_node *ret;

    ret = netsnmp_oid_stash_get_node(root, lookup, lookup_len);

    if (ret)

        return ret->thedata;

    return NULL;

}

#endif /* NETSNMP_FEATURE_REMOVE_OID_STASH_GET_DATA */

netsnmp_feature_child_of(oid_stash_store_all, oid_stash_all);

#ifndef NETSNMP_FEATURE_REMOVE_OID_STASH_STORE_ALL

/** a wrapper around netsnmp_oid_stash_store for use with a snmp_alarm.

 * when calling snmp_alarm, you can list this as a callback.  The

 * clientarg should be a pointer to a netsnmp_oid_stash_save_info

 * pointer.  It can also be called directly, of course.  The last

 * argument (clientarg) is the only one that is used.  The rest are

 * ignored by the function.

 * @param majorID

 * @param minorID

 * @param serverarg

 * @param clientarg A pointer to a netsnmp_oid_stash_save_info structure.

 */

int

netsnmp_oid_stash_store_all(int majorID, int minorID,

                            void *serverarg, void *clientarg) {

    oid oidbase[MAX_OID_LEN];

    netsnmp_oid_stash_save_info *sinfo;

    if (!clientarg)

        return SNMP_ERR_NOERROR;

    sinfo = (netsnmp_oid_stash_save_info *) clientarg;

    netsnmp_oid_stash_store(*(sinfo->root), sinfo->token, sinfo->dumpfn,

                            oidbase,0);

    return SNMP_ERR_NOERROR;

}

#endif /* NETSNMP_FEATURE_REMOVE_OID_STASH_STORE_ALL */

/** stores data in a stash tree to persistent storage.

    This function can be called to save all data in a stash tree to

    Net-SNMP's percent storage.  Make sure you register a parsing

    function with the read_config system to re-incorporate your saved

    data into future trees.

    @param root the top of the stash to store.

    @param tokenname the file token name to save in (passing "snmpd" will

    save things into snmpd.conf).

    @param dumpfn A function which can dump the data stored at a particular

    node into a char buffer.

    @param curoid must be a pointer to a OID array of length MAX_OID_LEN.

    @param curoid_len must be 0 for the top level call.

*/

void

netsnmp_oid_stash_store(netsnmp_oid_stash_node *root,

                        const char *tokenname, NetSNMPStashDump *dumpfn,

                        oid *curoid, size_t curoid_len) {

    char buf[SNMP_MAXBUF];

    netsnmp_oid_stash_node *tmpp;

    char *cp;

    char *appname = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID, 

                                          NETSNMP_DS_LIB_APPTYPE);

    int i;

    if (!tokenname || !root || !curoid || !dumpfn)

        return;

    for (i = 0; i < (int)root->children_size; i++) {

        if (root->children[i]) {

            for (tmpp = root->children[i]; tmpp; tmpp = tmpp->next_sibling) {

                curoid[curoid_len] = tmpp->value;

                if (tmpp->thedata) {

                    snprintf(buf, sizeof(buf), "%s ", tokenname);

                    cp = read_config_save_objid(buf+strlen(buf), curoid,

                                                curoid_len+1);

                    *cp++ = ' ';

                    *cp = '\0';

                    if ((*dumpfn)(cp, sizeof(buf) - strlen(buf),

                                  tmpp->thedata, tmpp))

                        read_config_store(appname, buf);

                }

                netsnmp_oid_stash_store(tmpp, tokenname, dumpfn,

                                        curoid, curoid_len+1);

            }

        }

    }

}

/** For debugging: dump the netsnmp_oid_stash tree to stdout

    @param root The top of the tree

    @param prefix a character string prefix printed to the beginning of each line.

*/

void 

oid_stash_dump(netsnmp_oid_stash_node *root, char *prefix)

{

    char            myprefix[MAX_OID_LEN * 4];

    netsnmp_oid_stash_node *tmpp;

    int             prefix_len = strlen(prefix) + 1;    /* actually it's +2 */

    unsigned int    i;

    memset(myprefix, ' ', MAX_OID_LEN * 4);

    myprefix[prefix_len] = '\0';

    for (i = 0; i < root->children_size; i++) {

        if (root->children[i]) {

            for (tmpp = root->children[i]; tmpp; tmpp = tmpp->next_sibling) {

                printf("%s%" NETSNMP_PRIo "d@%d: %s\n", prefix, tmpp->value, i,

                       (tmpp->thedata) ? "DATA" : "");

                oid_stash_dump(tmpp, myprefix);

            }

        }

    }

}

/** Frees the contents of a netsnmp_oid_stash tree.

    @param root the top of the tree (or branch to be freed)

    @param freefn The function to be called on each data (void *)

    pointer.  If left NULL the system free() function will be called

*/

void

netsnmp_oid_stash_free(netsnmp_oid_stash_node **root,

                       NetSNMPStashFreeNode *freefn) {

    netsnmp_oid_stash_node *curnode, *tmpp;

    unsigned int    i;

    if (!root || !*root)

        return;

    /* loop through all our children and free each node */

    for (i = 0; i < (*root)->children_size; i++) {

        if ((*root)->children[i]) {

            for(tmpp = (*root)->children[i]; tmpp; tmpp = curnode) {

                if (tmpp->thedata) {

                    if (freefn)

                        (*freefn)(tmpp->thedata);

                    else

                        free(tmpp->thedata);

                }

                curnode = tmpp->next_sibling;

                netsnmp_oid_stash_free(&tmpp, freefn);

            }

        }

    }

    free((*root)->children);

    free (*root);

    *root = NULL;

}

#else /* NETSNMP_FEATURE_REMOVE_OID_STASH */

netsnmp_feature_unused(oid_stash);

#endif/* NETSNMP_FEATURE_REMOVE_OID_STASH */

#ifndef NETSNMP_FEATURE_REMOVE_OID_STASH_NO_FREE

void

netsnmp_oid_stash_no_free(void *bogus)

{

    /* noop */

}

#endif /* NETSNMP_FEATURE_REMOVE_OID_STASH_NO_FREE */

/** @} */