用模板mib2c.iterate.conf生成表过程

1. 写mib 库文件  bvcom-AD988-MIB.txt 

2.复制mib库文件到/usr/local/share/snmp/mibs/

3.加载mib库（修改snmp.conf文件）
cat /usr/local/share/snmp/snmp.conf
mibs +bvcom-AD988-MIB.txt

4. 检查mib是否正常加载 snmptranslate -IR -Tp vsDevice

5. 查看mib2c支持的模板
border@debian:/work/border/snmp/example-demon$ ls /usr/local/share/snmp/ 
mib2c.access_functions.conf    mib2c.create-dataset.conf  mib2c.scalar.conf
mib2c.array-user.conf          mib2c-data                 mib2c.table_data.conf
mib2c.check_values.conf        mib2c.genhtml.conf         mibs
mib2c.check_values_local.conf  mib2c.int_watch.conf       snmp.conf
mib2c.column_defines.conf      mib2c.iterate_access.conf  snmp.conf~
mib2c.column_enums.conf        mib2c.iterate.conf         snmpconf-data
mib2c.column_storage.conf      mib2c.mfd.conf             snmpd.conf
mib2c.conf                     mib2c.notify.conf          snmp_perl.pl
mib2c.container.conf           mib2c.old-api.conf         snmp_perl_trapd.pl

6. 通过模板生成.c 和 .h 文件（）
border@debian:/work/border/snmp/example-demon$ mib2c -c mib2c.iterate.conf vsDevice

7. 通过 snmp_agent_api 编写守护程序 AD988DM.c
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <signal.h>
#include "vsDevice.h" 

static int keep_running;

RETSIGTYPE
stop_server(int a) {
    keep_running = 0;
}

int
main (int argc, char **argv) {

    int agentx_subagent=0; /* change this if you want to be a SNMP master agent */
    int background = 0; /* change this if you want to run in the background */
    int syslog = 0; /* change this if you want to use syslog */

    /* print log errors to syslog or stderr */

    if (syslog)
        snmp_enable_calllog();
    else
        snmp_enable_stderrlog();

    /* we're an agentx subagent? */
    if (agentx_subagent) {
        /* make us a agentx client. */
        netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, NETSNMP_DS_AGENT_ROLE, 1);
    }

    /* run in background, if requested */
    if (background && netsnmp_daemonize(1, !syslog))
        exit(1);


    /* Initialize tcpip, if necessary */
    SOCK_STARTUP;

    /* Initialize the agent library */
    init_agent("AD988DM"); // 配置文件名

    /* Initialize our mib code here */
    printf("Before init ViewScenes \n");

    init_vsDevice(); // 加载节点信息
    
    printf("End init ViewScenes \n");

    /* initialize vacm/usm access control  */
    if (!agentx_subagent) {
        void  init_vacm_vars();
        void  init_usmUser();
    }

    /* Example-demon will be used to read example-demon.conf files. */
    init_snmp("AD988DM");

    /* If we're going to be a snmp master agent, initial the ports */
    if (!agentx_subagent)
        init_master_agent();  /* open the port to listen on (defaults to udp:161) */

    printf("---------------------\n");
    /* In case we recevie a request to stop (kill -TERM or kill -INT) */
    keep_running = 1;
    signal(SIGTERM, stop_server);

    signal(SIGINT, stop_server);

    snmp_log(LOG_INFO,"AD988DM is up and running.\n");

    /* your main loop here... */
    while(keep_running) {
        /* if you use select(), see snmp_select_info() in snmp_api(3) */
        /*     --- OR ---  */
        agent_check_and_process(1); /* 0 == don't block */

    }

    /* at shutdown time */
    snmp_shutdown("AD988DM");
    SOCK_CLEANUP;
    return 0;
}
8. 编写Makefile文件，应用于编译。主要是make时候用到。
#
# Warning: you may need more libraries than are included here on the
# build line.  The agent frequently needs various libraries in order
# to compile pieces of it, but is OS dependent and we can't list all
# the combinations here.  Instead, look at the libraries that were
# used when linking the snmpd master agent and copy those to this
# file.
#

CC=gcc

OBJS2=AD988DM.o vsDevice.o

TARGETS=AD988DM

CFLAGS=-I. `net-snmp-config --cflags`
BUILDLIBS=`net-snmp-config --libs`
BUILDAGENTLIBS=`net-snmp-config --agent-libs`

# shared library flags (assumes gcc)
DLFLAGS=-fPIC -shared

all: $(TARGETS)

AD988DM: $(OBJS2)
	$(CC) -o AD988DM $(OBJS2)  $(BUILDAGENTLIBS)

clean:
	rm $(OBJS2) $(OBJS2) $(TARGETS)
9. 编写配置文件AD988DM.conf 并copy到 ~./snmp目录下。

###############################################################################
# Access Control
###############################################################################

#       sec.name  source          community
com2sec local     localhost       public
com2sec mynetwork 192.168.0.0/24      public

####
# Second, map the security names into group names:

#             	sec.model  sec.name
group MyRWGroup	v1         local
group MyRWGroup	v2c        local
group MyRWGroup	usm        local
group MyROGroup v1         mynetwork
group MyROGroup v2c        mynetwork
group MyROGroup usm        mynetwork

####
# Third, create a view for us to let the groups have rights to:

#           incl/excl subtree                          mask
view all    included  .1                               80

####
# Finally, grant the 2 groups access to the 1 view with different
# write permissions:

#                context sec.model sec.level match  read   write  notif
access MyROGroup ""      any       noauth    exact  all    none   none
access MyRWGroup ""      any       noauth    exact  all    all    none

agentaddress 161;

10.修改vsDevice.c（这是最重要一步，举其中的一个表为例，其他类推）
/** Initializes the vsDevice module */
void
init_vsDevice(void)
{
  /* here we initialize all the tables we're planning on supporting */
    initialize_table_vsDevTypeTable();
    initialize_table_vsDeviceTable();
    initialize_table_vsDevElementTable();
}

 // # Determine the first/last column names
/* Typical data structure for a row entry */
struct vsDevTypeTable_entry {
    /* Index values */
    long vsDevTypeIndex;

    /* Column values */
   // long vsDevTypeIndex;
    char vsDevTypeName[30];
    size_t vsDevTypeName_len;
    long vsDevTypeNum;

    /* Illustrate using a simple linked list */
    int   valid;
    struct vsDevTypeTable_entry *next;
};

struct vsDevTypeTable_entry  *vsDevTypeTable_head;

/* create a new row in the (unsorted) table */
struct vsDevTypeTable_entry *
vsDevTypeTable_createEntry(
                 long  vsDevTypeIndex,
///////////////////////////////////////////////////////添加的部分
                 char  *vsDevTypeName,
                 long  vsDevTypeNum
/////////////////////////////////////////////////////

                ) {
    struct vsDevTypeTable_entry *entry;

    entry = SNMP_MALLOC_TYPEDEF(struct vsDevTypeTable_entry);
    if (!entry)
        return NULL;

    entry->vsDevTypeIndex = vsDevTypeIndex;

////////////////////////////////////////////////////添加的部分
    strcpy((u_char*)entry->vsDevTypeName,vsDevTypeName);
    entry->vsDevTypeNum = vsDevTypeNum;
//////////////////////////////////////////////////// 
   entry->next = vsDevTypeTable_head;
    vsDevTypeTable_head = entry;
    return entry;

}


/** Initialize the vsDevTypeTable table by defining its contents and how it's structured */
void
initialize_table_vsDevTypeTable(void)
{
    static oid vsDevTypeTable_oid[] = {1,3,6,1,4,1,500000,9,3,1,2};
    size_t vsDevTypeTable_oid_len   = OID_LENGTH(vsDevTypeTable_oid);
    netsnmp_handler_registration    *reg;
    netsnmp_iterator_info           *iinfo;

    netsnmp_table_registration_info *table_info;

    reg = netsnmp_create_handler_registration(
              "vsDevTypeTable",     vsDevTypeTable_handler,
              vsDevTypeTable_oid, vsDevTypeTable_oid_len,
              HANDLER_CAN_RONLY
              );

    table_info = SNMP_MALLOC_TYPEDEF( netsnmp_table_registration_info );
    netsnmp_table_helper_add_indexes(table_info,
                           ASN_INTEGER,  /* index: vsDevTypeIndex */
                           0);
    table_info->min_column = COLUMN_VSDEVTYPEINDEX;
    table_info->max_column = COLUMN_VSDEVTYPENUM;
    
    iinfo = SNMP_MALLOC_TYPEDEF( netsnmp_iterator_info );
    iinfo->get_first_data_point = vsDevTypeTable_get_first_data_point;
    iinfo->get_next_data_point  = vsDevTypeTable_get_next_data_point;
    iinfo->table_reginfo        = table_info;
    
    netsnmp_register_table_iterator( reg, iinfo );

    /* Initialise the contents of the table here */
    vsDevTypeTable_createEntry(1, "sunligang", 24);//添加的部分
}

    
/* remove a row from the table */
void
vsDevTypeTable_removeEntry( struct vsDevTypeTable_entry *entry ) {
    struct vsDevTypeTable_entry *ptr, *prev;

    if (!entry)
        return;    /* Nothing to remove */

    for ( ptr  = vsDevTypeTable_head, prev = NULL;
          ptr != NULL;
          prev = ptr, ptr = ptr->next ) {
        if ( ptr == entry )
            break;
    }
    if ( !ptr )
        return;    /* Can't find it */

    if ( prev == NULL )
        vsDevTypeTable_head = ptr->next;
    else
        prev->next = ptr->next;

    SNMP_FREE( entry );   /* XXX - release any other internal resources */
}


/* Example iterator hook routines - using 'get_next' to do most of the work */
netsnmp_variable_list *
vsDevTypeTable_get_first_data_point(void **my_loop_context,
                          void **my_data_context,
                          netsnmp_variable_list *put_index_data,
                          netsnmp_iterator_info *mydata)
{
    *my_loop_context = vsDevTypeTable_head;
    return vsDevTypeTable_get_next_data_point(my_loop_context, my_data_context,
                                    put_index_data,  mydata );
}

netsnmp_variable_list *
vsDevTypeTable_get_next_data_point(void **my_loop_context,
                          void **my_data_context,
                          netsnmp_variable_list *put_index_data,
                          netsnmp_iterator_info *mydata)
{
    struct vsDevTypeTable_entry *entry = (struct vsDevTypeTable_entry *)*my_loop_context;
    netsnmp_variable_list *idx = put_index_data;

    if ( entry ) {
        snmp_set_var_typed_integer( idx, ASN_INTEGER, entry->vsDevTypeIndex );
        idx = idx->next_variable;
        *my_data_context = (void *)entry;
        *my_loop_context = (void *)entry->next;
        return put_index_data;
    } else {
        return NULL;
    }
}


/** handles requests for the vsDevTypeTable table */
int
vsDevTypeTable_handler(
    netsnmp_mib_handler               *handler,
    netsnmp_handler_registration      *reginfo,
    netsnmp_agent_request_info        *reqinfo,
    netsnmp_request_info              *requests) {

    netsnmp_request_info       *request;
    netsnmp_table_request_info *table_info;
    struct vsDevTypeTable_entry          *table_entry;

    switch (reqinfo->mode) {
        /*
         * Read-support (also covers GetNext requests)
         */
    case MODE_GET:
        for (request=requests; request; request=request->next) {
            table_entry = (struct vsDevTypeTable_entry *)
                              netsnmp_extract_iterator_context(request);
            table_info  =     netsnmp_extract_table_info(      request);
    
            switch (table_info->colnum) {
            case COLUMN_VSDEVTYPEINDEX:
                if ( !table_entry ) {
                    netsnmp_set_request_error(reqinfo, request,
                                              SNMP_NOSUCHINSTANCE);
                    continue;
                }
                snmp_set_var_typed_integer( request->requestvb, ASN_INTEGER,
                                            table_entry->vsDevTypeIndex);
                break;
            case COLUMN_VSDEVTYPENAME:
                if ( !table_entry ) {
                    netsnmp_set_request_error(reqinfo, request,
                                              SNMP_NOSUCHINSTANCE);
                    continue;
                }
                snmp_set_var_typed_value( request->requestvb, ASN_OCTET_STR,
                                 (u_char*)table_entry->vsDevTypeName,
                                          strlen(table_entry->vsDevTypeName));//添加的部分，最后一个变量是长度，需要修改
                break;
            case COLUMN_VSDEVTYPENUM:
                if ( !table_entry ) {
                    netsnmp_set_request_error(reqinfo, request,
                                              SNMP_NOSUCHINSTANCE);
                    continue;
                }
                snmp_set_var_typed_integer( request->requestvb, ASN_INTEGER,
                                            table_entry->vsDevTypeNum);
                break;
            default:
                netsnmp_set_request_error(reqinfo, request,
                                          SNMP_NOSUCHOBJECT);
                break;
            }
        }
        break;

    }
    return SNMP_ERR_NOERROR;
}
 
/*以上是第一个表的内容，已经成功取得*/


操作如下：
1.slg@slg-desktop:~/snmpan/slg/AD988DM/doc$ snmpwalk -v 2c -c public localhost vsDevTypeTable
bvcom-AD988-MIB::vsDevTypeIndex.1 = INTEGER: 1
bvcom-AD988-MIB::vsDevTypeName.1 = STRING: "sunligang"
bvcom-AD988-MIB::vsDevTypeNum.1 = INTEGER: 24
2.slg@slg-desktop:~/snmpan/slg/AD988DM/doc$ snmpwalk -v 2c -c public localhost vsDevice
bvcom-AD988-MIB::vsDevTypeIndex.1 = INTEGER: 1
bvcom-AD988-MIB::vsDevTypeName.1 = STRING: "sunligang"
bvcom-AD988-MIB::vsDevTypeNum.1 = INTEGER: 24
bvcom-AD988-MIB::vsDevTypeIndex.1 = INTEGER: 1
bvcom-AD988-MIB::vsDeviceIndex.1 = INTEGER: 2
bvcom-AD988-MIB::vsDeviceName.1 = STRING: "sunligang"
bvcom-AD988-MIB::vsDeviceStatusVal.1 = INTEGER: 22
bvcom-AD988-MIB::vsDeviceStatus.1 = STRING: "bvcom"
bvcom-AD988-MIB::vsDevTypeIndex.1 = INTEGER: 1
bvcom-AD988-MIB::vsDeviceIndex.1 = INTEGER: 2
bvcom-AD988-MIB::vsDeviceElementIndex.1 = INTEGER: 3
bvcom-AD988-MIB::vsDeviceElementName.1 = STRING: "sunligang"
bvcom-AD988-MIB::vsDeviceElementStatusVal.1 = INTEGER: 24
bvcom-AD988-MIB::vsDeviceElementStatus.1 = STRING: "zhangcl"
bvcom-AD988-MIB::vsDeviceElementStatus.1 = No mo







3.6         代码的合并

在实现整个mib时，只需把简单变量的初始化函数和表实现的初始化函数合并。在这里简单变量的初始化函数为：void init_foxmail。把表的初始化函数void initialize_table_ExampleTable放到init_foxmail内部 ，再将init_foxmail作为主函数的初始化函数，修改相关头文件的引用，代码的简单合并就完成了。最后以主函数建立工程编译全部文件。




实现v3：
在配置文件中添加：
rwuser bvcomslg
createUser bvcomslg MD5 "bvcomslg" DES

运行结果：
slg@slg-desktop:~/snmpan/slg/AD988DM$ snmpget -v3 -l authPriv -u bvcomslg -A bvcomslg -X bvcomslg localhost vsDevTypeName.2
bvcom-AD988-MIB::vsDevTypeName.2 = STRING: "sunligang"
slg@slg-desktop:~/snmpan/slg/AD988DM$ snmpwalk -v3 -l authPriv -u bvcomslg -A bvcomslg -X bvcomslg localhost vsDevice
bvcom-AD988-MIB::vsDevTypeNumber.0 = INTEGER: 0
bvcom-AD988-MIB::vsDevTypeIndex.2 = INTEGER: 2
bvcom-AD988-MIB::vsDevTypeName.2 = STRING: "sunligang"
bvcom-AD988-MIB::vsDevTypeNum.2 = INTEGER: 24
bvcom-AD988-MIB::vsDeviceNumber.0 = INTEGER: 0
bvcom-AD988-MIB::vsDevTypeIndex.2 = INTEGER: 2
bvcom-AD988-MIB::vsDeviceIndex.2 = INTEGER: 2
bvcom-AD988-MIB::vsDeviceName.2 = STRING: "sunligang"