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Diffstat (limited to 'ntpsnmpd/ntpSnmpSubagentObject.c')
| -rw-r--r-- | ntpsnmpd/ntpSnmpSubagentObject.c | 549 |
1 files changed, 549 insertions, 0 deletions
diff --git a/ntpsnmpd/ntpSnmpSubagentObject.c b/ntpsnmpd/ntpSnmpSubagentObject.c new file mode 100644 index 0000000..f65fedf --- /dev/null +++ b/ntpsnmpd/ntpSnmpSubagentObject.c @@ -0,0 +1,549 @@ +/***************************************************************************** + * + * ntpSnmpSubAgentObject.c + * + * This file provides the callback functions for net-snmp and registers the + * serviced MIB objects with the master agent. + * + * Each object has its own callback function that is called by the + * master agent process whenever someone queries the corresponding MIB + * object. + * + * At the moment this triggers a full send/receive procedure for each + * queried MIB object, one of the things that are still on my todo list: + * a caching mechanism that reduces the number of requests sent to the + * ntpd process. + * + ****************************************************************************/ +#include <ntp_snmp.h> +#include <ctype.h> +#include <ntp.h> +#include <libntpq.h> + +/* general purpose buffer length definition */ +#define NTPQ_BUFLEN 2048 + +char ntpvalue[NTPQ_BUFLEN]; + + +/***************************************************************************** + * + * ntpsnmpd_parse_string + * + * This function will parse a given NULL terminated string and cut it + * into a fieldname and a value part (using the '=' as the delimiter. + * The fieldname will be converted to uppercase and all whitespace + * characters are removed from it. + * The value part is stripped, e.g. all whitespace characters are removed + * from the beginning and end of the string. + * If the value is started and ended with quotes ("), they will be removed + * and everything between the quotes is left untouched (including + * whitespace) + * Example: + * server host name = hello world! + * will result in a field string "SERVERHOSTNAME" and a value + * of "hello world!". + * My first Parameter = " is this! " + * results in a field string "MYFIRSTPARAMETER" and a value " is this! " + **************************************************************************** + * Parameters: + * string const char * The source string to parse. + * NOTE: must be NULL terminated! + * field char * The buffer for the field name. + * fieldsize size_t The size of the field buffer. + * value char * The buffer for the value. + * valuesize size_t The size of the value buffer. + * + * Returns: + * size_t length of value string + ****************************************************************************/ + +size_t +ntpsnmpd_parse_string( + const char * string, + char * field, + size_t fieldsize, + char * value, + size_t valuesize + ) +{ + int i; + int j; + int loop; + size_t str_cnt; + size_t val_cnt; + + /* we need at least one byte to work with to simplify */ + if (fieldsize < 1 || valuesize < 1) + return 0; + + str_cnt = strlen(string); + + /* Parsing the field name */ + j = 0; + loop = TRUE; + for (i = 0; loop && i <= str_cnt; i++) { + switch (string[i]) { + + case '\t': /* Tab */ + case '\n': /* LF */ + case '\r': /* CR */ + case ' ': /* Space */ + break; + + case '=': + loop = FALSE; + break; + + default: + if (j < fieldsize) + field[j++] = toupper(string[i]); + } + } + + j = min(j, fieldsize - 1); + field[j] = '\0'; + + /* Now parsing the value */ + value[0] = '\0'; + j = 0; + for (val_cnt = 0; i < str_cnt; i++) { + if (string[i] > 0x0D && string[i] != ' ') + val_cnt = min(j + 1, valuesize - 1); + + if (value[0] != '\0' || + (string[i] > 0x0D && string[i] != ' ')) { + if (j < valuesize) + value[j++] = string[i]; + } + } + value[val_cnt] = '\0'; + + if (value[0] == '"') { + val_cnt--; + strlcpy(value, &value[1], valuesize); + if (val_cnt > 0 && value[val_cnt - 1] == '"') { + val_cnt--; + value[val_cnt] = '\0'; + } + } + + return val_cnt; +} + + +/***************************************************************************** + * + * ntpsnmpd_cut_string + * + * This function will parse a given NULL terminated string and cut it + * into fields using the specified delimiter character. + * It will then copy the requested field into a destination buffer + * Example: + * ntpsnmpd_cut_string(read:my:lips:fool, RESULT, ':', 2, sizeof(RESULT)) + * will copy "lips" to RESULT. + **************************************************************************** + * Parameters: + * src const char * The name of the source string variable + * NOTE: must be NULL terminated! + * dest char * The name of the string which takes the + * requested field content + * delim char The delimiter character + * fieldnumber int The number of the required field + * (start counting with 0) + * maxsize size_t The maximum size of dest + * + * Returns: + * size_t length of resulting dest string + ****************************************************************************/ + +size_t +ntpsnmpd_cut_string( + const char * string, + char * dest, + char delim, + int fieldnumber, + size_t maxsize + ) +{ + size_t i; + size_t j; + int l; + size_t str_cnt; + + if (maxsize < 1) + return 0; + + str_cnt = strlen(string); + j = 0; + memset(dest, 0, maxsize); + + /* Parsing the field name */ + for (i = 0, l = 0; i < str_cnt && l <= fieldnumber; i++) { + if (string[i] == delim) + l++; /* next field */ + else if (l == fieldnumber && j < maxsize) + dest[j++] = string[i]; + } + j = min(j, maxsize - 1); + dest[j] = '\0'; + + return j; +} + + +/***************************************************************************** + * + * read_ntp_value + * + * This function retrieves the value for a given variable, currently + * this only supports sysvars. It starts a full mode 6 send/receive/parse + * iteration and needs to be optimized, e.g. by using a caching mechanism + * + **************************************************************************** + * Parameters: + * variable char* The name of the required variable + * rbuffer char* The buffer where the value goes + * maxlength int Max. number of bytes for resultbuf + * + * Returns: + * u_int number of chars that have been copied to + * rbuffer + ****************************************************************************/ + +size_t +read_ntp_value( + const char * variable, + char * value, + size_t valuesize + ) +{ + size_t sv_len; + char sv_data[NTPQ_BUFLEN]; + + memset(sv_data, 0, sizeof(sv_data)); + sv_len = ntpq_read_sysvars(sv_data, sizeof(sv_data)); + + if (0 == sv_len) + return 0; + else + return ntpq_getvar(sv_data, sv_len, variable, value, + valuesize); +} + + +/***************************************************************************** + * + * The get_xxx functions + * + * The following function calls are callback functions that will be + * used by the master agent process to retrieve a value for a requested + * MIB object. + * + ****************************************************************************/ + + +int get_ntpEntSoftwareName (netsnmp_mib_handler *handler, + netsnmp_handler_registration *reginfo, + netsnmp_agent_request_info *reqinfo, + netsnmp_request_info *requests) +{ + char ntp_softwarename[NTPQ_BUFLEN]; + + memset (ntp_softwarename, 0, NTPQ_BUFLEN); + + switch (reqinfo->mode) { + case MODE_GET: + { + if ( read_ntp_value("product", ntpvalue, NTPQ_BUFLEN) ) + { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntpvalue, + strlen(ntpvalue) + ); + } + else if ( read_ntp_value("version", ntpvalue, NTPQ_BUFLEN) ) + { + ntpsnmpd_cut_string(ntpvalue, ntp_softwarename, ' ', 0, sizeof(ntp_softwarename)-1); + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntp_softwarename, + strlen(ntp_softwarename) + ); + } else { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)"N/A", + 3 + ); + } + break; + + } + + + default: + /* If we cannot get the information we need, we will return a generic error to the SNMP client */ + return SNMP_ERR_GENERR; + } + + return SNMP_ERR_NOERROR; +} + + +int get_ntpEntSoftwareVersion (netsnmp_mib_handler *handler, + netsnmp_handler_registration *reginfo, + netsnmp_agent_request_info *reqinfo, + netsnmp_request_info *requests) +{ + + switch (reqinfo->mode) { + case MODE_GET: + { + + if ( read_ntp_value("version", ntpvalue, NTPQ_BUFLEN) ) + { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntpvalue, + strlen(ntpvalue) + ); + } else { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)"N/A", + 3 + ); + } + break; + + } + + + default: + /* If we cannot get the information we need, we will return a generic error to the SNMP client */ + return SNMP_ERR_GENERR; + } + + return SNMP_ERR_NOERROR; +} + + +int get_ntpEntSoftwareVendor (netsnmp_mib_handler *handler, + netsnmp_handler_registration *reginfo, + netsnmp_agent_request_info *reqinfo, + netsnmp_request_info *requests) +{ + + switch (reqinfo->mode) { + case MODE_GET: + { + + if ( read_ntp_value("vendor", ntpvalue, NTPQ_BUFLEN) ) + { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntpvalue, + strlen(ntpvalue) + ); + } else { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)"N/A", + 3 + ); + } + break; + + default: + /* If we cannot get the information we need, we will return a generic error to the SNMP client */ + return SNMP_ERR_GENERR; + } + } + return SNMP_ERR_NOERROR; +} + + +int get_ntpEntSystemType (netsnmp_mib_handler *handler, + netsnmp_handler_registration *reginfo, + netsnmp_agent_request_info *reqinfo, + netsnmp_request_info *requests) +{ + + switch (reqinfo->mode) { + case MODE_GET: + { + + if ( read_ntp_value("systemtype", ntpvalue, NTPQ_BUFLEN) ) + { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntpvalue, + strlen(ntpvalue) + ); + } + + if ( read_ntp_value("system", ntpvalue, NTPQ_BUFLEN) ) + { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntpvalue, + strlen(ntpvalue) + ); + } else { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)"N/A", + 3 + ); + } + break; + + } + + + default: + /* If we cannot get the information we need, we will return a generic error to the SNMP client */ + return SNMP_ERR_GENERR; + } + + return SNMP_ERR_NOERROR; +} + + +/* + * ntpEntTimeResolution + * "The time resolution in integer format, where the resolution + * is represented as divisions of a second, e.g., a value of 1000 + * translates to 1.0 ms." + * + * ntpEntTimeResolution is a challenge for ntpd, as the resolution is + * not known nor exposed by ntpd, only the measured precision (time to + * read the clock). + * + * Logically the resolution must be at least the precision, so report + * it as our best approximation of resolution until/unless ntpd provides + * better. + */ +int +get_ntpEntTimeResolution( + netsnmp_mib_handler * handler, + netsnmp_handler_registration * reginfo, + netsnmp_agent_request_info * reqinfo, + netsnmp_request_info * requests + ) +{ + int precision; + u_int32 resolution; + + switch (reqinfo->mode) { + + case MODE_GET: + if (!read_ntp_value("precision", ntpvalue, + sizeof(ntpvalue))) + return SNMP_ERR_GENERR; + if (1 != sscanf(ntpvalue, "%d", &precision)) + return SNMP_ERR_GENERR; + if (precision >= 0) + return SNMP_ERR_GENERR; + precision = max(precision, -31); + resolution = 1 << -precision; + snmp_set_var_typed_value( + requests->requestvb, + ASN_UNSIGNED, + (void *)&resolution, + sizeof(resolution)); + break; + + default: + return SNMP_ERR_GENERR; + } + + return SNMP_ERR_NOERROR; +} + + +/* + * ntpEntTimePrecision + * "The entity's precision in integer format, shows the precision. + * A value of -5 would mean 2^-5 = 31.25 ms." + */ +int +get_ntpEntTimePrecision( + netsnmp_mib_handler * handler, + netsnmp_handler_registration * reginfo, + netsnmp_agent_request_info * reqinfo, + netsnmp_request_info * requests + ) +{ + int precision; + int32 precision32; + + switch (reqinfo->mode) { + + case MODE_GET: + if (!read_ntp_value("precision", ntpvalue, + sizeof(ntpvalue))) + return SNMP_ERR_GENERR; + if (1 != sscanf(ntpvalue, "%d", &precision)) + return SNMP_ERR_GENERR; + precision32 = (int32)precision; + snmp_set_var_typed_value( + requests->requestvb, + ASN_INTEGER, + (void *)&precision32, + sizeof(precision32)); + break; + + default: + return SNMP_ERR_GENERR; + } + + return SNMP_ERR_NOERROR; +} + + +int get_ntpEntTimeDistance (netsnmp_mib_handler *handler, + netsnmp_handler_registration *reginfo, + netsnmp_agent_request_info *reqinfo, + netsnmp_request_info *requests) +{ + switch (reqinfo->mode) { + case MODE_GET: + { + + if ( read_ntp_value("rootdelay", ntpvalue, NTPQ_BUFLEN) ) + { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)ntpvalue, + strlen(ntpvalue) + ); + } else { + snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR, + (u_char *)"N/A", + 3 + ); + } + break; + + } + + + default: + /* If we cannot get the information we need, we will return a generic error to the SNMP client */ + return SNMP_ERR_GENERR; + } + + return SNMP_ERR_NOERROR; +} + + +/* + * + * Initialize sub agent + */ + +void +init_ntpSnmpSubagentObject(void) +{ + /* Register all MIB objects with the agentx master */ + NTP_OID_RO( ntpEntSoftwareName, 1, 1, 1, 0); + NTP_OID_RO( ntpEntSoftwareVersion, 1, 1, 2, 0); + NTP_OID_RO( ntpEntSoftwareVendor, 1, 1, 3, 0); + NTP_OID_RO( ntpEntSystemType, 1, 1, 4, 0); + NTP_OID_RO( ntpEntTimeResolution, 1, 1, 5, 0); + NTP_OID_RO( ntpEntTimePrecision, 1, 1, 6, 0); + NTP_OID_RO( ntpEntTimeDistance, 1, 1, 7, 0); +} + |