snmpv3.c

snmp up 2

                    "NOT setting engineIDNic, engineID already set\n"));
    }
}

/*******************************************************************-o-******
 * engineID_conf
 *
 * Parameters:
 *	*word
 *	*cptr
 *
 * This function reads a string from the configuration file and uses that
 * string to initialize the engineID.  It's assumed to be human readable.
 */
void
engineID_conf(const char *word, char *cptr)
{
    setup_engineID(NULL, cptr);
    DEBUGMSGTL(("snmpv3", "initialized engineID with: %s\n", cptr));
}

void
version_conf(const char *word, char *cptr)
{
    if (strcmp(cptr, "1") == 0) {
        netsnmp_ds_set_int(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_SNMPVERSION, 
			   NETSNMP_DS_SNMP_VERSION_1);       /* bogus value */
    } else if (strcasecmp(cptr, "2c") == 0) {
        netsnmp_ds_set_int(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_SNMPVERSION, 
			   NETSNMP_DS_SNMP_VERSION_2c);
    } else if (strcmp(cptr, "3") == 0) {
        netsnmp_ds_set_int(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_SNMPVERSION, 
			   NETSNMP_DS_SNMP_VERSION_3);
    } else {
        config_perror("Unknown version specification");
        return;
    }
    DEBUGMSGTL(("snmpv3", "set default version to %d\n",
                netsnmp_ds_get_int(NETSNMP_DS_LIBRARY_ID, 
				   NETSNMP_DS_LIB_SNMPVERSION)));
}

/*
 * engineID_old_conf(const char *, char *):
 * 
 * Reads a octet string encoded engineID into the oldEngineID and
 * oldEngineIDLen pointers.
 */
void
oldengineID_conf(const char *word, char *cptr)
{
    read_config_read_octet_string(cptr, &oldEngineID, &oldEngineIDLength);
}


/*******************************************************************-o-******
 * init_snmpv3
 *
 * Parameters:
 *	*type	Label for the config file "type" used by calling entity.
 *      
 * Set time and engineID.
 * Set parsing functions for config file tokens.
 * Initialize SNMP Crypto API (SCAPI).
 */
void
init_snmpv3(const char *type)
{

    gettimeofday(&snmpv3starttime, NULL);

    if (!type)
        type = "__snmpapp__";

    /*
     * we need to be called back later 
     */
    snmp_register_callback(SNMP_CALLBACK_LIBRARY,
                           SNMP_CALLBACK_POST_READ_CONFIG,
                           init_snmpv3_post_config, NULL);
    snmp_register_callback(SNMP_CALLBACK_LIBRARY,
                           SNMP_CALLBACK_POST_PREMIB_READ_CONFIG,
                           init_snmpv3_post_premib_config, NULL);
    /*
     * we need to be called back later 
     */
    snmp_register_callback(SNMP_CALLBACK_LIBRARY, SNMP_CALLBACK_STORE_DATA,
                           snmpv3_store, (void *) strdup(type));

    /*
     * initialize submodules 
     */
    /*
     * NOTE: this must be after the callbacks are registered above,
     * since they need to be called before the USM callbacks. 
     */
    init_secmod();

    /*
     * register all our configuration handlers (ack, there's a lot) 
     */

    /*
     * handle engineID setup before everything else which may depend on it 
     */
    register_prenetsnmp_mib_handler(type, "engineID", engineID_conf, NULL,
                                    "string");
    register_prenetsnmp_mib_handler(type, "oldEngineID", oldengineID_conf,
                                    NULL, NULL);
    register_prenetsnmp_mib_handler(type, "engineIDType",
                                    engineIDType_conf, NULL, "num");
    register_prenetsnmp_mib_handler(type, "engineIDNic", engineIDNic_conf,
                                    NULL, "string");
    register_config_handler(type, "engineBoots", engineBoots_conf, NULL,
                            NULL);

    /*
     * default store config entries 
     */
    netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "defSecurityName",
			       NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_SECNAME);
    netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "defContext", 
			       NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_CONTEXT);
    netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "defPassphrase",
			     NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_PASSPHRASE);
    netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "defAuthPassphrase",
			 NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_AUTHPASSPHRASE);
    netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "defPrivPassphrase",
			 NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_PRIVPASSPHRASE);
    register_config_handler("snmp", "defVersion", version_conf, NULL,
                            "1|2c|3");

    register_config_handler("snmp", "defAuthType", snmpv3_authtype_conf,
                            NULL, "MD5|SHA");
    register_config_handler("snmp", "defPrivType", snmpv3_privtype_conf,
                            NULL,
#ifdef HAVE_AES
                            "DES (AES support not available)");
#else
                            "DES|AES128|AES192|AES256");
#endif
    register_config_handler("snmp", "defSecurityLevel",
                            snmpv3_secLevel_conf, NULL,
                            "noAuthNoPriv|authNoPriv|authPriv");
    register_config_handler(type, "userSetAuthPass", usm_set_password,
                            NULL, NULL);
    register_config_handler(type, "userSetPrivPass", usm_set_password,
                            NULL, NULL);
    register_config_handler(type, "userSetAuthKey", usm_set_password, NULL,
                            NULL);
    register_config_handler(type, "userSetPrivKey", usm_set_password, NULL,
                            NULL);
    register_config_handler(type, "userSetAuthLocalKey", usm_set_password,
                            NULL, NULL);
    register_config_handler(type, "userSetPrivLocalKey", usm_set_password,
                            NULL, NULL);
}

/*
 * initializations for SNMPv3 to be called after the configuration files
 * have been read.
 */

int
init_snmpv3_post_config(int majorid, int minorid, void *serverarg,
                        void *clientarg)
{

    size_t          engineIDLen;
    u_char         *c_engineID;

    c_engineID = snmpv3_generate_engineID(&engineIDLen);

    if (engineIDLen == 0) {
        /*
         * Somethine went wrong - help! 
         */
        return SNMPERR_GENERR;
    }

    /*
     * if our engineID has changed at all, the boots record must be set to 1 
     */
    if (engineIDLen != (int) oldEngineIDLength ||
        oldEngineID == NULL || c_engineID == NULL ||
        memcmp(oldEngineID, c_engineID, engineIDLen) != 0) {
        engineBoots = 1;
    }

    /*
     * set our local engineTime in the LCD timing cache 
     */
    set_enginetime(c_engineID, engineIDLen,
                   snmpv3_local_snmpEngineBoots(),
                   snmpv3_local_snmpEngineTime(), TRUE);

    free(c_engineID);
    return SNMPERR_SUCCESS;
}

int
init_snmpv3_post_premib_config(int majorid, int minorid, void *serverarg,
                               void *clientarg)
{
    if (!engineIDIsSet)
        setup_engineID(NULL, NULL);

    return SNMPERR_SUCCESS;
}

/*******************************************************************-o-******
 * store_snmpv3
 *
 * Parameters:
 *	*type
 */
int
snmpv3_store(int majorID, int minorID, void *serverarg, void *clientarg)
{
    char            line[SNMP_MAXBUF_SMALL];
    u_char          c_engineID[SNMP_MAXBUF_SMALL];
    int             engineIDLen;
    const char     *type = (const char *) clientarg;

    if (type == NULL)           /* should never happen, since the arg is ours */
        type = "unknown";

    sprintf(line, "engineBoots %ld", engineBoots);
    read_config_store(type, line);

    engineIDLen = snmpv3_get_engineID(c_engineID, SNMP_MAXBUF_SMALL);

    if (engineIDLen) {
        /*
         * store the engineID used for this run 
         */
        sprintf(line, "oldEngineID ");
        read_config_save_octet_string(line + strlen(line), c_engineID,
                                      engineIDLen);
        read_config_store(type, line);
    }
    return SNMPERR_SUCCESS;
}                               /* snmpv3_store() */

u_long
snmpv3_local_snmpEngineBoots(void)
{
    return engineBoots;
}


/*******************************************************************-o-******
 * snmpv3_get_engineID
 *
 * Parameters:
 *	*buf
 *	 buflen
 *      
 * Returns:
 *	Length of engineID	On Success
 *	SNMPERR_GENERR		Otherwise.
 *
 *
 * Store engineID in buf; return the length.
 *
 */
size_t
snmpv3_get_engineID(u_char * buf, size_t buflen)
{
    /*
     * Sanity check.
     */
    if (!buf || (buflen < engineIDLength)) {
        return 0;
    }

    memcpy(buf, engineID, engineIDLength);
    return engineIDLength;

}                               /* end snmpv3_get_engineID() */

/*******************************************************************-o-******
 * snmpv3_clone_engineID
 *
 * Parameters:
 *	**dest
 *       *dest_len
 *       src
 *	 srclen
 *      
 * Returns:
 *	Length of engineID	On Success
 *	0		        Otherwise.
 *
 *
 * Clones engineID, creates memory
 *
 */
int
snmpv3_clone_engineID(u_char ** dest, size_t * destlen, u_char * src,
                      size_t srclen)
{
    if (!dest || !destlen)
        return 0;

    if (*dest) {
        SNMP_FREE(*dest);
        *dest = NULL;
    }
    *destlen = 0;

    if (srclen && src) {
        *dest = (u_char *) malloc(srclen);
        if (*dest == NULL)
            return 0;
        memmove(*dest, src, srclen);
        *destlen = srclen;
    }
    return *destlen;
}                               /* end snmpv3_clone_engineID() */


/*******************************************************************-o-******
 * snmpv3_generate_engineID
 *
 * Parameters:
 *	*length
 *      
 * Returns:
 *	Pointer to copy of engineID	On Success.
 *	NULL				If malloc() or snmpv3_get_engineID()
 *						fail.
 *
 * Generates a malloced copy of our engineID.
 *
 * 'length' is set to the length of engineID  -OR-  < 0 on failure.
 */
u_char         *
snmpv3_generate_engineID(size_t * length)
{
    u_char         *newID;
    newID = (u_char *) malloc(engineIDLength);

    if (newID) {
        *length = snmpv3_get_engineID(newID, engineIDLength);
    }

    if (*length == 0) {
        SNMP_FREE(newID);
        newID = NULL;
    }

    return newID;

}                               /* end snmpv3_generate_engineID() */

/*
 * snmpv3_local_snmpEngineTime(): return the number of seconds since the
 * snmpv3 engine last incremented engine_boots 
 */
u_long
snmpv3_local_snmpEngineTime(void)
{
    struct timeval  now;

    gettimeofday(&now, NULL);
    return calculate_time_diff(&now, &snmpv3starttime) / 100;
}


/*
 * Code only for Linux systems 
 */
#if defined(IFHWADDRLEN) && defined(SIOCGIFHWADDR)
static int
getHwAddress(const char *networkDevice, /* e.g. "eth0", "eth1" */
             char *addressOut)
{                               /* return address. Len=IFHWADDRLEN */
    /*
     * getHwAddress(...)
     * *
     * *  This function will return a Network Interfaces Card's Hardware
     * *  address (aka MAC address).
     * *
     * *  Input Parameter(s):
     * *      networkDevice - a null terminated string with the name of a network
     * *                      device.  Examples: eth0, eth1, etc...
     * *
     * *  Output Parameter(s):
     * *      addressOut -    This is the binary value of the hardware address.
     * *                      This value is NOT converted into a hexadecimal string.
     * *                      The caller must pre-allocate for a return value of
     * *                      length IFHWADDRLEN
     * *
     * *  Return value:   This function will return zero (0) for success.  If
     * *                  an error occurred the function will return -1.
     * *
     * *  Caveats:    This has only been tested on Ethernet networking cards.
     */
    int             sock;       /* our socket */
    struct ifreq    request;    /* struct which will have HW address */

    if ((NULL == networkDevice) || (NULL == addressOut)) {
        return -1;
    }
    /*
     * In order to find out the hardware (MAC) address of our system under
     * * Linux we must do the following:
     * * 1.  Create a socket
     * * 2.  Do an ioctl(...) call with the SIOCGIFHWADDRLEN operation.
     */
    sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0) {
        return -1;
    }
    /*
     * erase the request block 
     */
    memset(&request, 0, sizeof(request));
    /*
     * copy the name of the net device we want to find the HW address for 
     */
    strncpy(request.ifr_name, networkDevice, IFNAMSIZ - 1);
    /*
     * Get the HW address 
     */
    if (ioctl(sock, SIOCGIFHWADDR, &request)) {
        close(sock);
        return -1;
    }
    close(sock);
    memcpy(addressOut, request.ifr_hwaddr.sa_data, IFHWADDRLEN);
    return 0;
}
#endif

#ifdef SNMP_TESTING_CODE
/*
 * snmpv3_set_engineBootsAndTime(): this function does not exist.  Go away. 
 */
/*
 * It certainly should never be used, unless in a testing scenero,
 * which is why it was created 
 */
void
snmpv3_set_engineBootsAndTime(int boots, int ttime)
{
    engineBoots = boots;
    gettimeofday(&snmpv3starttime, NULL);
    snmpv3starttime.tv_sec -= ttime;
}
#endif