/*

 * 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.

 */

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

#include <net-snmp/library/snmpUDPIPv6Domain.h>

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

#include <net-snmp/types.h>

#ifdef NETSNMP_TRANSPORT_UDPIPV6_DOMAIN

#include <stdio.h>

#include <sys/types.h>

#include <ctype.h>

#include <errno.h>

#if HAVE_STRING_H

#include <string.h>

#else

#include <strings.h>

#endif

#include <stddef.h>

#if HAVE_STDLIB_H

#include <stdlib.h>

#endif

#if HAVE_UNISTD_H

#include <unistd.h>

#endif

#if HAVE_SYS_SOCKET_H

#include <sys/socket.h>

#endif

#if defined(HAVE_WINSOCK_H) && !defined(mingw32)

static const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;

#endif

#if HAVE_NETINET_IN_H

#include <netinet/in.h>

#endif

#if HAVE_ARPA_INET_H

#include <arpa/inet.h>

#endif

#if HAVE_NETDB_H

#include <netdb.h>

#endif

#if HAVE_NET_IF_H

#include <net/if.h>

#endif

#if HAVE_DMALLOC_H

#include <dmalloc.h>

#endif

#if HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY

#define SS_FAMILY ss_family

#elif HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY

#define SS_FAMILY __ss_family

#endif

#if defined(darwin)

#include <stdint.h> /* for uint8_t */

#endif

#include <net-snmp/types.h>

#include <net-snmp/output_api.h>

#include <net-snmp/config_api.h>

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

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

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

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

#ifndef NETSNMP_NO_SYSTEMD

#include <net-snmp/library/sd-daemon.h>

#endif

#include "inet_ntop.h"

#include "inet_pton.h"

oid netsnmp_UDPIPv6Domain[] = { TRANSPORT_DOMAIN_UDP_IPV6 };

static netsnmp_tdomain udp6Domain;

/*

 * Return a string representing the address in data, or else the "far end"

 * address if data is NULL.  

 */

static char *

netsnmp_udp6_fmtaddr(netsnmp_transport *t, const void *data, int len)

{

    return netsnmp_ipv6_fmtaddr("UDP/IPv6", t, data, len);

}

/*

 * You can write something into opaque that will subsequently get passed back 

 * to your send function if you like.  For instance, you might want to

 * remember where a PDU came from, so that you can send a reply there...  

 */

static int

netsnmp_udp6_recv(netsnmp_transport *t, void *buf, int size,

		  void **opaque, int *olength)

{

    int             rc = -1;

    socklen_t       fromlen = sizeof(struct sockaddr_in6);

    struct sockaddr *from;

    if (t != NULL && t->sock >= 0) {

        from = (struct sockaddr *) malloc(sizeof(struct sockaddr_in6));

        if (from == NULL) {

            *opaque = NULL;

            *olength = 0;

            return -1;

        } else {

            memset(from, 0, fromlen);

        }

	while (rc < 0) {

	  rc = recvfrom(t->sock, buf, size, 0, from, &fromlen);

	  if (rc < 0 && errno != EINTR) {

	    break;

	  }

	}

        if (rc >= 0) {

            DEBUGIF("netsnmp_udp6") {

                char *str = netsnmp_udp6_fmtaddr(NULL, from, fromlen);

                DEBUGMSGTL(("netsnmp_udp6",

                            "recvfrom fd %d got %d bytes (from %s)\n", t->sock,

                            rc, str));

                free(str);

            }

        } else {

            DEBUGMSGTL(("netsnmp_udp6", "recvfrom fd %d err %d (\"%s\")\n",

			t->sock, errno, strerror(errno)));

        }

        *opaque = (void *) from;

        *olength = sizeof(struct sockaddr_in6);

    }

    return rc;

}

static int

netsnmp_udp6_send(netsnmp_transport *t, const void *buf, int size,

		  void **opaque, int *olength)

{

    int rc = -1;

    const struct sockaddr *to = NULL;

    if (opaque != NULL && *opaque != NULL &&

        *olength == sizeof(struct sockaddr_in6)) {

        to = (const struct sockaddr *) (*opaque);

    } else if (t != NULL && t->data != NULL &&

               ((t->data_length == sizeof(struct sockaddr_in6)) ||

                (t->data_length == sizeof(netsnmp_indexed_addr_pair)))) {

        to = (const struct sockaddr *) (t->data);

    }

    if (to != NULL && t != NULL && t->sock >= 0) {

        DEBUGIF("netsnmp_udp6") {

            char *str = netsnmp_udp6_fmtaddr(NULL, to,

                                             sizeof(struct sockaddr_in6));

            DEBUGMSGTL(("netsnmp_udp6",

                        "send %d bytes from %p to %s on fd %d\n",

                        size, buf, str, t->sock));

            free(str);

        }

	while (rc < 0) {

	    rc = sendto(t->sock, buf, size, 0, to,sizeof(struct sockaddr_in6));

	    if (rc < 0 && errno != EINTR) {

		break;

	    }

	}

    }

    return rc;

}

/*

 * Initialize a UDP/IPv6-based transport for SNMP.  Local is TRUE if addr is the

 * local address to bind to (i.e. this is a server-type session); otherwise

 * addr is the remote address to send things to.  

 */

netsnmp_transport *

netsnmp_udp6_transport_init(const struct sockaddr_in6 *addr, int flags)

{

    netsnmp_transport *t = NULL;

    int             local = flags & NETSNMP_TSPEC_LOCAL;

    u_char         *addr_ptr;

#ifdef NETSNMP_NO_LISTEN_SUPPORT

    if (local)

        return NULL;

#endif /* NETSNMP_NO_LISTEN_SUPPORT */

    if (addr == NULL || addr->sin6_family != AF_INET6) {

        return NULL;

    }

    t = SNMP_MALLOC_TYPEDEF(netsnmp_transport);

    if (t == NULL) {

        return NULL;

    }

    t->sock = -1;

    addr_ptr = netsnmp_memdup(addr, sizeof(*addr));

    if (addr_ptr == NULL) {

        free(t);

        return NULL;

    }

    if (local) {

        /** This is a server session. */

        t->local_length = sizeof(*addr);

        t->local = addr_ptr;

    } else {

        /** This is a client session. */

        t->remote = addr_ptr;

        t->remote_length = sizeof(*addr);

    }

    DEBUGIF("netsnmp_udp6") {

        char *str = netsnmp_udp6_fmtaddr(NULL, addr, sizeof(*addr));

        DEBUGMSGTL(("netsnmp_udp6", "open %s %s\n", local ? "local" : "remote",

                    str));

        free(str);

    }

    if (!local) {

        netsnmp_indexed_addr_pair *addr_pair;

        /*

         * allocate space to save the (remote) address in the

         * transport-specific data pointer for later use by netsnmp_udp_send.

         */

        t->data = calloc(1, sizeof(netsnmp_indexed_addr_pair));

        if (NULL == t->data) {

            netsnmp_transport_free(t);

            return NULL;

        }

        t->data_length = sizeof(netsnmp_indexed_addr_pair);

        addr_pair = (netsnmp_indexed_addr_pair *)t->data;

        memcpy(&addr_pair->remote_addr, addr, sizeof(*addr));

    }

    /*

     * 16-bit length field, 8 byte UDP header, 40 byte IPv6 header.

     */

    t->msgMaxSize = 0xffff - 8 - 40;

    t->f_recv     = netsnmp_udp6_recv;

    t->f_send     = netsnmp_udp6_send;

    t->f_close    = netsnmp_socketbase_close;

    t->f_accept   = NULL;

    t->f_fmtaddr  = netsnmp_udp6_fmtaddr;

    t->f_get_taddr = netsnmp_ipv6_get_taddr;

    t->domain = netsnmp_UDPIPv6Domain;

    t->domain_length =

        sizeof(netsnmp_UDPIPv6Domain) / sizeof(netsnmp_UDPIPv6Domain[0]);

    return t;

}

int

netsnmp_udp6_transport_bind(netsnmp_transport *t,

                            const struct sockaddr_in6 *addr,

                            int flags)

{

    int             local = flags & NETSNMP_TSPEC_LOCAL;

    int             rc = 0;

    if (local) {

#ifndef NETSNMP_NO_LISTEN_SUPPORT

        /*

         * This session is intended as a server, so we must bind on to the

         * given IP address, which may include an interface address, or could

         * be INADDR_ANY, but certainly includes a port number.

         */

#ifdef IPV6_V6ONLY

        /* Try to restrict PF_INET6 socket to IPv6 communications only. */

        {

            int one=1;

            if (setsockopt(t->sock, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&one, sizeof(one)) != 0) {

                DEBUGMSGTL(("netsnmp_udp6", "couldn't set IPV6_V6ONLY to %d bytes: %s\n", one, strerror(errno)));

            } 

        }

#endif

#else /* NETSNMP_NO_LISTEN_SUPPORT */

        return -1;

#endif /* NETSNMP_NO_LISTEN_SUPPORT */

    }

    DEBUGIF("netsnmp_udp6") {

        char *str;

        str = netsnmp_udp6_fmtaddr(NULL, addr, sizeof(*addr));

        DEBUGMSGTL(("netsnmp_udpbase", "binding socket: %d to %s\n",

                    t->sock, str));

        free(str);

    }

    rc = bind(t->sock, (const struct sockaddr *)addr, sizeof(*addr));

    if (rc != 0) {

        DEBUGMSGTL(("netsnmp_udp6", "failed to bind for clientaddr: %d %s\n",

                    errno, strerror(errno)));

        netsnmp_socketbase_close(t);

        return -1;

    }

    return 0;

}

int

netsnmp_udp6_transport_socket(int flags)

{

    int local = flags & NETSNMP_TSPEC_LOCAL;

    int sock = socket(PF_INET6, SOCK_DGRAM, 0);

    DEBUGMSGTL(("UDPBase", "opened socket %d as local=%d\n", sock, local));

    if (sock < 0)

        return -1;

    _netsnmp_udp_sockopt_set(sock, local);

    return sock;

}

void

netsnmp_udp6_transport_get_bound_addr(netsnmp_transport *t)

{

    netsnmp_indexed_addr_pair *addr_pair;

    socklen_t                  local_addr_len = sizeof(addr_pair->local_addr);

    int                        rc;

    /** only for client transports: must have data and not local */

    if (NULL == t || NULL != t->local || NULL == t->data ||

        t->data_length < local_addr_len) {

        snmp_log(LOG_ERR, "bad parameters for get bound addr\n");

        return;

    }

    addr_pair = (netsnmp_indexed_addr_pair *)t->data;

    /** get local socket address for client session */

    local_addr_len = sizeof(addr_pair->local_addr);

    rc = getsockname(t->sock, (struct sockaddr*)&addr_pair->local_addr,

                     &local_addr_len);

    netsnmp_assert(rc == 0);

    DEBUGIF("netsnmp_udpbase") {

        char *str = netsnmp_udp6_fmtaddr(NULL, (void *)&addr_pair->local_addr,

                                         sizeof(addr_pair->local_addr));

        DEBUGMSGTL(("netsnmp_udpbase", "socket %d bound to %s\n",

                    t->sock, str));

        free(str);

    }

}

netsnmp_transport *

netsnmp_udpipv6base_tspec_transport(netsnmp_tdomain_spec *tspec)

{

    struct sockaddr_in6 addr;

    int local;

    if (NULL == tspec)

        return NULL;

    local = tspec->flags & NETSNMP_TSPEC_LOCAL;

    /** get address from target */

    if (!netsnmp_sockaddr_in6_2(&addr, tspec->target, tspec->default_target))

        return NULL;

    if (NULL != tspec->source) {

        struct sockaddr_in6 src_addr, *srcp = &src_addr;

        /** get sockaddr from source */

        if (!netsnmp_sockaddr_in6_2(&src_addr, tspec->source, NULL))

            return NULL;

        return netsnmp_udp6_transport_with_source(&addr, local, srcp);

     } else {

        /** if no source and we do not want any default client address */

        if (tspec->flags & NETSNMP_TSPEC_NO_DFTL_CLIENT_ADDR)

            return netsnmp_udp6_transport_with_source(&addr, local,

                                                             NULL);

    }

    /** no source and default client address ok */

    return netsnmp_udp6_transport(&addr, local);

}

netsnmp_transport *

netsnmp_udp6_transport_with_source(const struct sockaddr_in6 *addr, int local,

                                   const struct sockaddr_in6 *src_addr)

{

    netsnmp_transport         *t = NULL;

    const struct sockaddr_in6 *bind_addr;

    int                        rc, flags = 0;

    t = netsnmp_udp6_transport_init(addr, local);

    if (NULL == t)

        return NULL;

    if (local) {

        bind_addr = addr;

        flags |= NETSNMP_TSPEC_LOCAL;

#ifndef NETSNMP_NO_SYSTEMD

        /*

         * Maybe the socket was already provided by systemd...

         */

        t->sock = netsnmp_sd_find_inet_socket(PF_INET6, SOCK_DGRAM, -1,

                                              ntohs(addr->sin6_port));

#endif

    }

    else

        bind_addr = src_addr;

    if (-1 == t->sock)

        t->sock = netsnmp_udp6_transport_socket(flags);

    if (t->sock < 0) {

        netsnmp_transport_free(t);

        return NULL;

    }

    /*

     * If we've been given an address to bind to, then bind to it.

     * Otherwise the OS will use "something sensible".

     */

    if (NULL == bind_addr)

        return t;

    rc = netsnmp_udp6_transport_bind(t, bind_addr, flags);

    if (rc) {

        netsnmp_transport_free(t);

        t = NULL;

    }

    else if (!local)

        netsnmp_udp6_transport_get_bound_addr(t);

    return t;

}

/*

 * Open a UDP/IPv6-based transport for SNMP.  Local is TRUE if addr is the

 * local address to bind to (i.e. this is a server-type session); otherwise

 * addr is the remote address to send things to.

 */

netsnmp_transport *

netsnmp_udp6_transport(const struct sockaddr_in6 *addr, int local)

{

    if (!local) {

        const char *client_socket;

        client_socket = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,

                                              NETSNMP_DS_LIB_CLIENT_ADDR);

        if (client_socket) {

            struct sockaddr_in6 client_addr;

            if(netsnmp_sockaddr_in6_2(&client_addr, client_socket, NULL)) {

                return netsnmp_udp6_transport_with_source(addr, local,

                                                          &client_addr);

            }

        }

    }

    return netsnmp_udp6_transport_with_source(addr, local, NULL);

}

#if !defined(NETSNMP_DISABLE_SNMPV1) || !defined(NETSNMP_DISABLE_SNMPV2C)

/*

 * The following functions provide the "com2sec6" configuration token

 * functionality for compatibility.

 */

#define EXAMPLE_NETWORK       "NETWORK"

#define EXAMPLE_COMMUNITY     "COMMUNITY"

typedef struct com2Sec6Entry_s {

    const char     *secName;

    const char     *contextName;

    struct com2Sec6Entry_s *next;

    struct in6_addr network;

    struct in6_addr mask;

    int             negate;

    const char      community[1];

} com2Sec6Entry;

static com2Sec6Entry  *com2Sec6List = NULL, *com2Sec6ListLast = NULL;

NETSNMP_STATIC_INLINE int

create_com2Sec6Entry(const struct addrinfo* const run,

                     const struct in6_addr* const mask,

                     const char* const secName,

                     const size_t secNameLen,

                     const char* const contextName,

                     const size_t contextNameLen,

                     const char* const community,

                     const size_t communityLen,

                     int negate,

                     com2Sec6Entry** const begin,

                     com2Sec6Entry** const end)

{

    const struct sockaddr_in6 * const run_addr =

        (const struct sockaddr_in6*)run->ai_addr;

    int i;

    /* Check that the network and mask are consistent. */

    for (i = 0; i < 16; ++i) {

        if (run_addr->sin6_addr.s6_addr[i] & ~mask->s6_addr[i]) {

            config_perror("source/mask mismatch");

            return 1;

        }

    }

    {

        char buf1[INET6_ADDRSTRLEN];

        char buf2[INET6_ADDRSTRLEN];

        DEBUGMSGTL(("netsnmp_udp6_parse_security",

                    "<\"%s\", %s/%s> => \"%s\"\n",

                    community,

                    inet_ntop(AF_INET6, &run_addr->sin6_addr,

                              buf1, sizeof(buf1)),

                    inet_ntop(AF_INET6, mask, buf2, sizeof(buf2)),

                    secName));

    }

    {

        /* Allocate all the needed chunks */

        void * const v =

            malloc(offsetof(com2Sec6Entry, community) + communityLen +

                   secNameLen + contextNameLen);

        com2Sec6Entry* const e = (com2Sec6Entry*)v;

        char *last = ((char*)v) + offsetof(com2Sec6Entry, community);

        if (v == NULL) {

            config_perror("memory error");

            return 1;

        }

        memcpy(last, community, communityLen);

        last += communityLen;

        memcpy(last, secName, secNameLen);

        e->secName = last;

        last += secNameLen;

        if (contextNameLen) {

            memcpy(last, contextName, contextNameLen);

            e->contextName = last;

        } else

            e->contextName = last - 1;

        memcpy(&e->network, &run_addr->sin6_addr, sizeof(struct in6_addr));

        memcpy(&e->mask, mask, sizeof(struct in6_addr));

        e->negate = negate;

        e->next = NULL;

        if (*end != NULL) {

            (*end)->next = e;

            *end = e;

        } else {

            *end = *begin = e;

        }

    }

    return 0;

}

void

netsnmp_udp6_parse_security(const char *token, char *param)

{

    /** copy_nword does null term, so we need vars of max size + 2. */

    /** (one for null, one to detect param too long */

    char            secName[VACMSTRINGLEN]; /* == VACM_MAX_STRING + 2 */

    size_t          secNameLen;

    char            contextName[VACMSTRINGLEN];

    size_t          contextNameLen;

    char            community[COMMUNITY_MAX_LEN + 2];/* overflow + null char */

    size_t          communityLen;

    char            source[301]; /* !(1)+dns-name(253)+/(1)+mask(45)+\0(1) */

    char            *sourcep;

    struct in6_addr mask;

    int             negate;

    /*

     * Get security, source address/netmask and community strings.

     */

    param = copy_nword( param, secName, sizeof(secName));

    if (strcmp(secName, "-Cn") == 0) {

        if (!param) {

            config_perror("missing CONTEXT_NAME parameter");

            return;

        }

        param = copy_nword( param, contextName, sizeof(contextName));

        contextNameLen = strlen(contextName);

        if (contextNameLen > VACM_MAX_STRING) {

            config_perror("context name too long");

            return;

        }

        if (!param) {

            config_perror("missing NAME parameter");

            return;

        }

        ++contextNameLen; /* null termination */

        param = copy_nword( param, secName, sizeof(secName));

    } else {

        contextNameLen = 0;

    }

    secNameLen = strlen(secName);

    if (secNameLen == 0) {

        config_perror("empty NAME parameter");

        return;

    } else if (secNameLen > VACM_MAX_STRING) {

        config_perror("security name too long");

        return;

    }

    ++secNameLen; /* null termination */

    if (!param) {

        config_perror("missing SOURCE parameter");

        return;

    }

    param = copy_nword( param, source, sizeof(source));

    if (source[0] == '\0') {

        config_perror("empty SOURCE parameter");

        return;

    }

    if (strncmp(source, EXAMPLE_NETWORK, strlen(EXAMPLE_NETWORK)) == 0) {

        config_perror("example config NETWORK not properly configured");

        return;

    }

    if (!param) {

        config_perror("missing COMMUNITY parameter");

        return;

    }

    param = copy_nword( param, community, sizeof(community));

    if (community[0] == '\0') {

        config_perror("empty COMMUNITY parameter");

        return;

    }

    communityLen = strlen(community);

    if (communityLen > COMMUNITY_MAX_LEN) {

        config_perror("community name too long");

        return;

    }

    ++communityLen; /* null termination */

    if (communityLen == sizeof(EXAMPLE_COMMUNITY) &&

        memcmp(community, EXAMPLE_COMMUNITY, sizeof(EXAMPLE_COMMUNITY)) == 0) {

        config_perror("example config COMMUNITY not properly configured");

        return;

    }

    /* Possible mask cases

     * "default" <=> 0::0/0

     * <hostname>[/] <=> <hostname>/128

     * <hostname>/number <=> <hostname>/number

     * <hostname>/<mask> <=> <hostname>/<mask>

     */

    {

        /* Deal with the "default" case first. */

        const int isdefault = strcmp(source, "default") == 0;

        if (isdefault) {

            memset(mask.s6_addr, '\0', sizeof(mask.s6_addr));

            negate = 0;

            sourcep = NULL;    /* gcc gets confused about sourcep being used */

        } else {

            if (*source == '!') {

               negate = 1;

               sourcep = source + 1;

            } else {

               negate = 0;

               sourcep = source;

            }

            /* Split the source/netmask parts */

            char *strmask = strchr(sourcep, '/');

            if (strmask != NULL)

                /* Mask given. */

                *strmask++ = '\0';

            /* Try to interpret the mask */

            if (strmask == NULL || *strmask == '\0') {

                /* No mask was given. Assume /128 */

                memset(mask.s6_addr, '\xff', sizeof(mask.s6_addr));

            } else {

                /* Try to interpret mask as a "number of 1 bits". */

                char* cp;

                long masklength = strtol(strmask, &cp, 10);

                if (*cp == '\0') {

                    if (0 <= masklength && masklength <= 128) {

                        const int j = masklength / 8;

                        const int jj = masklength % 8;

                        memset(mask.s6_addr, '\xff', j);

                        if (j < 16) {

                            mask.s6_addr[j] = ((uint8_t)~0U << (8 - jj));

                            memset(mask.s6_addr + j + 1, '\0', 15 - j);

                        }

                    } else {

                        config_perror("bad mask length");

                        return;

                    }

                }

                /* Try to interpret mask numerically. */

                else if (inet_pton(AF_INET6, strmask, &mask) != 1) {

                    config_perror("bad mask");

                    return;

                }

            }

        }

        {

            struct sockaddr_in6 pton_addr;

            struct addrinfo hints, *res = NULL;

            memset(&hints, '\0', sizeof(hints));

            /* First check if default, otherwise try to parse as a numeric

             * address, if that also fails try to lookup the address */

            if (isdefault) {

                memset(&pton_addr.sin6_addr.s6_addr, '\0',

                       sizeof(struct in6_addr));

            } else if (inet_pton(AF_INET6, sourcep, &pton_addr.sin6_addr) != 1) {

                /* Nope, wasn't a numeric address. Must be a hostname. */

#if HAVE_GETADDRINFO

                int             gai_error;

                hints.ai_family = AF_INET6;

                hints.ai_socktype = SOCK_DGRAM;

                gai_error = netsnmp_getaddrinfo(sourcep, NULL, &hints, &res;;

                if (gai_error != 0) {

                    config_perror(gai_strerror(gai_error));

                    return;

                }

#else

                config_perror("getaddrinfo() not available");

                return;

#endif

            }

            if (res == NULL) {

                hints.ai_addrlen = sizeof(pton_addr);

                hints.ai_addr = (struct sockaddr*)&pton_addr;

                hints.ai_next = NULL;

                res = &hints;

            }

            {

                struct addrinfo *run;

                int    failed = 0;

                com2Sec6Entry *begin = NULL, *end = NULL;

                for (run = res; run && !failed; run = run->ai_next)

                    failed =

                        create_com2Sec6Entry(run, &mask,

                                             secName, secNameLen,

                                             contextName, contextNameLen,

                                             community, communityLen, negate,

                                             &begin, &end;;

                if (failed) {

                    /* Free eventually allocated chunks */

                    while (begin) {

                        end = begin;

                        begin = begin->next;

                        free(end);

                    }

                } else if (com2Sec6ListLast != NULL) {

                    com2Sec6ListLast->next = begin;

                    com2Sec6ListLast = end;

                } else {

                    com2Sec6List = begin;

                    com2Sec6ListLast = end;

                }

            }

#if HAVE_GETADDRINFO

            if (res != &hints)

                freeaddrinfo(res);

#endif

        }

    }

}

void

netsnmp_udp6_com2Sec6List_free(void)

{

    com2Sec6Entry  *e = com2Sec6List;

    while (e != NULL) {

        com2Sec6Entry  *tmp = e;

        e = e->next;

        free(tmp);

    }

    com2Sec6List = com2Sec6ListLast = NULL;

}

#endif /* support for community based SNMP */

void

netsnmp_udp6_agent_config_tokens_register(void)

{

#if !defined(NETSNMP_DISABLE_SNMPV1) || !defined(NETSNMP_DISABLE_SNMPV2C)

    register_app_config_handler("com2sec6", netsnmp_udp6_parse_security,

                                netsnmp_udp6_com2Sec6List_free,

                                "[-Cn CONTEXT] secName IPv6-network-address[/netmask] community");

#endif /* support for community based SNMP */

}

#if !defined(NETSNMP_DISABLE_SNMPV1) || !defined(NETSNMP_DISABLE_SNMPV2C)

/*

 * Return 0 if there are no com2sec entries, or return 1 if there ARE com2sec

 * entries.  On return, if a com2sec entry matched the passed parameters,

 * then *secName points at the appropriate security name, or is NULL if the

 * parameters did not match any com2sec entry.

 */

int

netsnmp_udp6_getSecName(void *opaque, int olength,

                        const char *community,

                        int community_len,

                        const char **secName, const char **contextName)

{

    const com2Sec6Entry *c;

    struct sockaddr_in6 *from = (struct sockaddr_in6 *) opaque;

    char           *ztcommunity = NULL;

    char            str6[INET6_ADDRSTRLEN];

    if (secName != NULL) {

        *secName = NULL;  /* Haven't found anything yet */

    }

    /*

     * Special case if there are NO entries (as opposed to no MATCHING

     * entries).

     */

    if (com2Sec6List == NULL) {

        DEBUGMSGTL(("netsnmp_udp6_getSecName", "no com2sec entries\n"));

        return 0;

    }

    /*

     * If there is no IPv6 source address, then there can be no valid security

     * name.

     */

    if (opaque == NULL || olength != sizeof(struct sockaddr_in6)

        || from->sin6_family != PF_INET6) {

        DEBUGMSGTL(("netsnmp_udp6_getSecName",

                    "no IPv6 source address in PDU?\n"));

        return 1;

    }

    ztcommunity = (char *) malloc(community_len + 1);

    if (ztcommunity != NULL) {

        memcpy(ztcommunity, community, community_len);

        ztcommunity[community_len] = '\0';

    }

    inet_ntop(AF_INET6, &from->sin6_addr, str6, sizeof(str6));

    DEBUGMSGTL(("netsnmp_udp6_getSecName", "resolve <\"%s\", %s>\n",

                ztcommunity ? ztcommunity : "<malloc error>", str6));

    for (c = com2Sec6List; c != NULL; c = c->next) {

        {

            char buf1[INET6_ADDRSTRLEN];

            char buf2[INET6_ADDRSTRLEN];

            DEBUGMSGTL(("netsnmp_udp6_getSecName",