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

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

/*

 * Portions of this file are copyrighted by:

 * Copyright (c) 2016 VMware, Inc. All rights reserved.

 * Use is subject to license terms specified in the COPYING file

 * distributed with the Net-SNMP package.

 */

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#include <stdio.h>

#ifdef HAVE_STRING_H

#include <string.h>

#else

#include <strings.h>

#endif

#include <sys/types.h>

#include <net-snmp/types.h>

#include <net-snmp/config_api.h>

#include <net-snmp/library/snmp_enum.h>

#include <net-snmp/library/tools.h>

#include <net-snmp/library/system.h>      /* strcasecmp() */

#include <net-snmp/library/snmp_assert.h>

netsnmp_feature_child_of(snmp_enum_all, libnetsnmp);

netsnmp_feature_child_of(se_find_free_value_in_slist, snmp_enum_all);

netsnmp_feature_child_of(snmp_enum_store_list, snmp_enum_all);

netsnmp_feature_child_of(snmp_enum_store_slist, snmp_enum_all);

netsnmp_feature_child_of(snmp_enum_clear, snmp_enum_all);

struct snmp_enum_list_str {

    char           *name;

    struct snmp_enum_list *list;

    struct snmp_enum_list_str *next;

};

static struct snmp_enum_list **snmp_enum_lists;

static unsigned int current_maj_num;

static unsigned int current_min_num;

static struct snmp_enum_list_str *sliststorage;

static void

free_enum_list(struct snmp_enum_list *list);

int

init_snmp_enum(const char *type)

{

    if (NULL != snmp_enum_lists)

        return SE_OK;

    snmp_enum_lists = calloc(SE_MAX_IDS * SE_MAX_SUBIDS,

                             sizeof(*snmp_enum_lists));

    if (!snmp_enum_lists)

        return SE_NOMEM;

    current_maj_num = SE_MAX_IDS;

    current_min_num = SE_MAX_SUBIDS;

    register_const_config_handler(type, "enum", se_read_conf, NULL, NULL);

    return SE_OK;

}

void

se_read_conf(const char *word, const char *cptr)

{

    int major, minor;

    int value;

    const char *cp, *cp2;

    char e_name[BUFSIZ];

    char e_enum[  BUFSIZ];

    if (!cptr || *cptr=='\0')

        return;

    /*

     * Extract the first token

     *   (which should be the name of the list)

     */

    cp = copy_nword_const(cptr, e_name, sizeof(e_name));

    cp = skip_white_const(cp);

    if (!cp || *cp=='\0')

        return;

    /*

     * Add each remaining enumeration to the list,

     *   using the appropriate style interface

     */

    if (sscanf(e_name, "%d:%d", &major, &minor) == 2) {

        /*

         *  Numeric major/minor style

         */

        while (1) {

            cp = copy_nword_const(cp, e_enum, sizeof(e_enum));

            if (sscanf(e_enum, "%d:", &value) != 1) {

                break;

            }

            cp2 = e_enum;

            while (*cp2 != 0 && *cp2++ != ':')

                ;

            se_add_pair(major, minor, strdup(cp2), value);

            if (!cp)

                break;

        }

    } else {

        /*

         *  Named enumeration

         */

        while (1) {

            cp = copy_nword_const(cp, e_enum, sizeof(e_enum));

            if (sscanf(e_enum, "%d:", &value) != 1) {

                break;

            }

            cp2 = e_enum;

            while (*cp2 != 0 && *cp2++ != ':')

                ;

            se_add_pair_to_slist(e_name, strdup(cp2), value);

            if (!cp)

                break;

        }

    }

}

void

se_store_enum_list(struct snmp_enum_list *new_list,

                   const char *token, const char *type)

{

    struct snmp_enum_list *listp = new_list;

    char line[2048];

    char buf[512];

    int  len;

    snprintf(line, sizeof(line), "enum %s", token);

    while (listp) {

        snprintf(buf, sizeof(buf), " %d:%s", listp->value, listp->label);

        /*

         * Calculate the space left in the buffer.

         * If this is not sufficient to include the next enum,

         *   then save the line so far, and start again.

         */

  len = sizeof(line) - strlen(line);

  if ((int)strlen(buf) > len) {

      read_config_store(type, line);

            snprintf(line, sizeof(line), "enum %s", token);

      len = sizeof(line) - strlen(line);

  }

  strncat(line, buf, len);

        listp = listp->next;

    }

    read_config_store(type, line);

}

#ifndef NETSNMP_FEATURE_REMOVE_SNMP_ENUM_STORE_LIST

void

se_store_list(unsigned int major, unsigned int minor, const char *type)

{

    char token[32];

    snprintf(token, sizeof(token), "%d:%d", major, minor);

    se_store_enum_list(se_find_list(major, minor), token, type);

}

#endif /* NETSNMP_FEATURE_REMOVE_SNMP_ENUM_STORE_LIST */

static struct snmp_enum_list **

se_find_list_ptr(unsigned int major, unsigned int minor)

{

    if (major >= current_maj_num || minor >= current_min_num)

        return NULL;

    netsnmp_assert(NULL != snmp_enum_lists);

    return &snmp_enum_lists[major * current_min_num + minor];

}

struct snmp_enum_list *

se_find_list(unsigned int major, unsigned int minor)

{

    struct snmp_enum_list **p = se_find_list_ptr(major, minor);

    return p ? *p : NULL;

}

int

se_find_value_in_list(struct snmp_enum_list *list, const char *label)

{

    if (!list)

        return SE_DNE;          /* XXX: um, no good solution here */

    while (list) {

        if (strcmp(list->label, label) == 0)

            return (list->value);

        list = list->next;

    }

    return SE_DNE;              /* XXX: um, no good solution here */

}

int

se_find_casevalue_in_list(struct snmp_enum_list *list, const char *label)

{

    if (!list)

        return SE_DNE;          /* XXX: um, no good solution here */

    while (list) {

        if (strcasecmp(list->label, label) == 0)

            return (list->value);

        list = list->next;

    }

    return SE_DNE;              /* XXX: um, no good solution here */

}

int

se_find_free_value_in_list(struct snmp_enum_list *list)

{

    int max_value = 0;

    if (!list)

        return SE_DNE;

    for (;list; list=list->next) {

        if (max_value < list->value)

            max_value = list->value;

    }

    return max_value+1;

}

int

se_find_value(unsigned int major, unsigned int minor, const char *label)

{

    return se_find_value_in_list(se_find_list(major, minor), label);

}

int

se_find_free_value(unsigned int major, unsigned int minor)

{

    return se_find_free_value_in_list(se_find_list(major, minor));

}

char           *

se_find_label_in_list(struct snmp_enum_list *list, int value)

{

    if (!list)

        return NULL;

    while (list) {

        if (list->value == value)

            return (list->label);

        list = list->next;

    }

    return NULL;

}

char           *

se_find_label(unsigned int major, unsigned int minor, int value)

{

    return se_find_label_in_list(se_find_list(major, minor), value);

}

/*

 * Ownership of 'label' is transferred from the caller to this function.

 * 'label' is freed if list insertion fails.

 */

int

se_add_pair_to_list(struct snmp_enum_list **list, char *label, int value)

{

    struct snmp_enum_list *lastnode = NULL, *new_node, *tmp;

    if (!list) {

        free(label);

        return SE_DNE;

    }

    tmp = *list;

    while (tmp) {

        if (tmp->value == value) {

            free(label);

            return (SE_ALREADY_THERE);

        }

        lastnode = tmp;

        tmp = tmp->next;

    }

    new_node = SNMP_MALLOC_STRUCT(snmp_enum_list);

    if (!new_node) {

        free(label);

        return (SE_NOMEM);

    }

    if (lastnode)

        lastnode->next = new_node;

    else

        *list = new_node;

    new_node->label = label;

    new_node->value = value;

    new_node->next = NULL;

    return (SE_OK);

}

int

se_add_pair(unsigned int major, unsigned int minor, char *label, int value)

{

    return se_add_pair_to_list(se_find_list_ptr(major, minor), label, value);

}

/*

 * remember a list of enums based on a lookup name.

 */

static struct snmp_enum_list **

se_find_slist_ptr(const char *listname)

{

    struct snmp_enum_list_str *sptr;

    if (!listname)

        return NULL;

    for (sptr = sliststorage; sptr != NULL; sptr = sptr->next)

        if (sptr->name && strcmp(sptr->name, listname) == 0)

            return &sptr->list;

    return NULL;

}

struct snmp_enum_list *

se_find_slist(const char *listname)

{

    struct snmp_enum_list **ptr = se_find_slist_ptr(listname);

    return ptr ? *ptr : NULL;

}

char           *

se_find_label_in_slist(const char *listname, int value)

{

    return (se_find_label_in_list(se_find_slist(listname), value));

}

int

se_find_value_in_slist(const char *listname, const char *label)

{

    return (se_find_value_in_list(se_find_slist(listname), label));

}

int

se_find_casevalue_in_slist(const char *listname, const char *label)

{

    return (se_find_casevalue_in_list(se_find_slist(listname), label));

}

#ifndef NETSNMP_FEATURE_REMOVE_SE_FIND_FREE_VALUE_IN_SLIST

int

se_find_free_value_in_slist(const char *listname)

{

    return (se_find_free_value_in_list(se_find_slist(listname)));

}

#endif /* NETSNMP_FEATURE_REMOVE_SE_FIND_FREE_VALUE_IN_SLIST */

/*

 * Ownership of 'label' is transferred from the caller to this function.

 * 'label' is freed if list insertion fails.

 */

int

se_add_pair_to_slist(const char *listname, char *label, int value)

{

    struct snmp_enum_list **list_p = se_find_slist_ptr(listname);

    if (!list_p) {

        struct snmp_enum_list_str *sptr =

            SNMP_MALLOC_STRUCT(snmp_enum_list_str);

        if (!sptr) {

            free(label);

            return SE_NOMEM;

        }

        sptr->next = sliststorage;

        sptr->name = strdup(listname);

        if (!sptr->name) {

            free(sptr);

            free(label);

            return SE_NOMEM;

        }

        list_p = &sptr->list;

        sliststorage = sptr;

    }

    return se_add_pair_to_list(list_p, label, value);

}

static void

free_enum_list(struct snmp_enum_list *list)

{

    struct snmp_enum_list *next;

    while (list) {

        next = list->next;

        SNMP_FREE(list->label);

        SNMP_FREE(list);

        list = next;

    }

}

void

clear_snmp_enum(void)

{

    struct snmp_enum_list_str *sptr = sliststorage, *next = NULL;

    unsigned int major, minor;

    while (sptr != NULL) {

  next = sptr->next;

  free_enum_list(sptr->list);

  SNMP_FREE(sptr->name);

  SNMP_FREE(sptr);

  sptr = next;

    }

    sliststorage = NULL;

    for (major = 0; major < current_maj_num; major++) {

        for (minor = 0; minor < current_min_num; minor++) {

            struct snmp_enum_list **list_ptr = se_find_list_ptr(major, minor);

            if (!list_ptr || !*list_ptr)

                continue;

            free_enum_list(*list_ptr);

        }

    }

    current_maj_num = 0;

    current_min_num = 0;

    SNMP_FREE(snmp_enum_lists);

}

void

se_clear_list(struct snmp_enum_list **list)

{

    struct snmp_enum_list *this_entry, *next_entry;

    if (!list)

        return;

    this_entry = *list;

    while (this_entry) {

        next_entry = this_entry->next;

        SNMP_FREE(this_entry->label);

        SNMP_FREE(this_entry);

        this_entry = next_entry;

    }

    *list = NULL;

    return;

}

#ifndef NETSNMP_FEATURE_REMOVE_SNMP_ENUM_STORE_SLIST

void

se_store_slist(const char *listname, const char *type)

{

    struct snmp_enum_list *list = se_find_slist(listname);

    se_store_enum_list(list, listname, type);

}

int

se_store_slist_callback(int majorID, int minorID,

                        void *serverargs, void *clientargs)

{

    char *appname = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,

                                          NETSNMP_DS_LIB_APPTYPE);

    se_store_slist((char *)clientargs, appname);

    return SNMPERR_SUCCESS;

}

#endif /* NETSNMP_FEATURE_REMOVE_SNMP_ENUM_STORE_SLIST */

#ifndef NETSNMP_FEATURE_REMOVE_SNMP_ENUM_CLEAR

void

se_clear_slist(const char *listname)

{

    se_clear_list(se_find_slist_ptr(listname));

}

void

se_clear_all_lists(void)

{

    struct snmp_enum_list_str *sptr = NULL;

    for (sptr = sliststorage; sptr != NULL; sptr = sptr->next)

        se_clear_list(&(sptr->list));

}

#endif /* NETSNMP_FEATURE_REMOVE_SNMP_ENUM_CLEAR */