client_intf.c

开发snmp的开发包有两个开放的SNMP开发库

#include <Python.h>

#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
#ifdef I_SYS_TIME
#include <sys/time.h>
#endif
#include <netdb.h>
#include <stdlib.h>

#ifdef HAVE_REGEX_H
#include <regex.h>
#endif

#define SUCCESS 1
#define FAILURE 0

#define VARBIND_TAG_F 0
#define VARBIND_IID_F 1
#define VARBIND_VAL_F 2
#define VARBIND_TYPE_F 3

#define TYPE_UNKNOWN 0
#define MAX_TYPE_NAME_LEN 32
#define STR_BUF_SIZE (MAX_TYPE_NAME_LEN * MAX_OID_LEN)
#define ENG_ID_BUF_SIZE 32

#define NO_RETRY_NOSUCH 0

/* these should be part of transform_oids.h ? */
#define USM_AUTH_PROTO_MD5_LEN 10
#define USM_AUTH_PROTO_SHA_LEN 10
#define USM_PRIV_PROTO_DES_LEN 10

#define STRLEN(x) (x ? strlen(x) : 0)

typedef netsnmp_session SnmpSession;
typedef struct tree SnmpMibNode;
static void __recalc_timeout (struct timeval*,struct timeval*,
                                struct timeval*,struct timeval*, int* );
static in_addr_t __parse_address (char*);
static int __is_numeric_oid (char*);
static int __is_leaf (struct tree*);
static int __translate_appl_type (char*);
static int __translate_asn_type (int);
static int __snprint_value (char *, size_t,
                              netsnmp_variable_list*, struct tree *,
                             int, int);
static int __sprint_num_objid (char *, oid *, int);
static int __scan_num_objid (char *, oid *, size_t *);
static int __get_type_str (int, char *);
static int __get_label_iid (char *, char **, char **, int);
static int __oid_cmp (oid *, int, oid *, int);
static int __tp_sprint_num_objid (char*,SnmpMibNode *);
static SnmpMibNode * __get_next_mib_node (SnmpMibNode *);
static struct tree * __oid2tp (oid*, int, struct tree *, int*);
static struct tree * __tag2oid (char *, char *, oid  *, int  *, int *, int);
static int __concat_oid_str (oid *, int *, char *);
static int __add_var_val_str (netsnmp_pdu *, oid *, int, char *,
                                 int, int);
#define USE_NUMERIC_OIDS 0x08
#define NON_LEAF_NAME 0x04
#define USE_LONG_NAMES 0x02
#define FAIL_ON_NULL_IID 0x01
#define NO_FLAGS 0x00


/* Wrapper around fprintf(stderr, ...) for clean and easy debug output. */
static int _debug_level = 0;
#ifdef	DEBUGGING
#define	DBPRT(severity, otherargs)					\
	do {								\
	    if (_debug_level && severity <= _debug_level) {		\
	      (void)printf(otherargs);					\
	    }								\
	} while (/*CONSTCOND*/0)
#else	/* DEBUGGING */
#define	DBPRT(severity, otherargs)	/* Ignore */
#endif	/* DEBUGGING */

#define SAFE_FREE(x) do {if (x != NULL) free(x);} while(/*CONSTCOND*/0)

void
__libraries_init(char *appname)
{
  static int have_inited = 0;

  if (have_inited)
    return;
  have_inited = 1;

  snmp_set_quick_print(1);
  snmp_enable_stderrlog();
  init_snmp(appname);
    
  netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_DONT_BREAKDOWN_OIDS, 1);
  netsnmp_ds_set_int(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_PRINT_SUFFIX_ONLY, 1);
  netsnmp_ds_set_int(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_OID_OUTPUT_FORMAT,
		     NETSNMP_OID_OUTPUT_SUFFIX);
}

static void
__recalc_timeout (tvp, ctvp, ltvp, itvp, block)
struct timeval* tvp;
struct timeval* ctvp;
struct timeval* ltvp;
struct timeval* itvp;
int *block;
{
   struct timeval now;

   if (!timerisset(itvp)) return;  /* interval zero means loop forever */
   *block = 0;
   gettimeofday(&now,(struct timezone *)0);

   if (ctvp->tv_sec < 0) { /* first time or callback just fired */
      timersub(&now,ltvp,ctvp);
      timersub(ctvp,itvp,ctvp);
      timersub(itvp,ctvp,ctvp);
      timeradd(ltvp,itvp,ltvp);
   } else {
      timersub(&now,ltvp,ctvp);
      timersub(itvp,ctvp,ctvp);
   }

   /* flag is set for callback but still hasnt fired so set to something
    * small and we will service packets first if there are any ready
    * (also guard against negative timeout - should never happen?)
    */
   if (!timerisset(ctvp) || ctvp->tv_sec < 0 || ctvp->tv_usec < 0) {
      ctvp->tv_sec = 0;
      ctvp->tv_usec = 10;
   }

   /* if snmp timeout > callback timeout or no more requests to process */
   if (timercmp(tvp, ctvp, >) || !timerisset(tvp)) {
      *tvp = *ctvp; /* use the smaller non-zero timeout */
      timerclear(ctvp); /* used as a flag to let callback fire on timeout */
   }
}

static in_addr_t
__parse_address(address)
char *address;
{
    in_addr_t addr;
    struct sockaddr_in saddr;
    struct hostent *hp;

    if ((addr = inet_addr(address)) != -1)
	return addr;
    hp = gethostbyname(address);
    if (hp == NULL){
        return (-1); /* error value */
    } else {
	memcpy(&saddr.sin_addr, hp->h_addr, hp->h_length);
	return saddr.sin_addr.s_addr;
    }

}

static int
__is_numeric_oid (oidstr)
char* oidstr;
{
  if (!oidstr) return 0;
  for (; *oidstr; oidstr++) {
     if (isalpha((int)*oidstr)) return 0;
  }
  return(1);
}

static int
__is_leaf (tp)
struct tree* tp;
{
   char buf[MAX_TYPE_NAME_LEN];
   return (tp && (__get_type_str(tp->type,buf) || 
		  (tp->parent && __get_type_str(tp->parent->type,buf) )));
}

static SnmpMibNode*
__get_next_mib_node (tp)
SnmpMibNode* tp;
{
   /* printf("tp = %lX, parent = %lX, peer = %lX, child = %lX\n",
              tp, tp->parent, tp->next_peer, tp->child_list); */
   if (tp->child_list) return(tp->child_list);
   if (tp->next_peer) return(tp->next_peer);
   if (!tp->parent) return(NULL);
   for (tp = tp->parent; !tp->next_peer; tp = tp->parent) {
      if (!tp->parent) return(NULL);
   }
   return(tp->next_peer);
}

static int
__translate_appl_type(typestr)
char* typestr;
{
	if (typestr == NULL || *typestr == '\0') return TYPE_UNKNOWN;

	if (!strncasecmp(typestr,"INTEGER32",8))
            return(TYPE_INTEGER32);
	if (!strncasecmp(typestr,"INTEGER",3))
            return(TYPE_INTEGER);
	if (!strncasecmp(typestr,"UNSIGNED32",3))
            return(TYPE_UNSIGNED32);
	if (!strcasecmp(typestr,"COUNTER")) /* check all in case counter64 */
            return(TYPE_COUNTER);
	if (!strncasecmp(typestr,"GAUGE",3))
            return(TYPE_GAUGE);
	if (!strncasecmp(typestr,"IPADDR",3))
            return(TYPE_IPADDR);
	if (!strncasecmp(typestr,"OCTETSTR",3))
            return(TYPE_OCTETSTR);
	if (!strncasecmp(typestr,"TICKS",3))
            return(TYPE_TIMETICKS);
	if (!strncasecmp(typestr,"OPAQUE",3))
            return(TYPE_OPAQUE);
	if (!strncasecmp(typestr,"OBJECTID",3))
            return(TYPE_OBJID);
	if (!strncasecmp(typestr,"NETADDR",3))
	    return(TYPE_NETADDR);
	if (!strncasecmp(typestr,"COUNTER64",3))
	    return(TYPE_COUNTER64);
	if (!strncasecmp(typestr,"NULL",3))
	    return(TYPE_NULL);
	if (!strncasecmp(typestr,"BITS",3))
	    return(TYPE_BITSTRING);
	if (!strncasecmp(typestr,"ENDOFMIBVIEW",3))
	    return(SNMP_ENDOFMIBVIEW);
	if (!strncasecmp(typestr,"NOSUCHOBJECT",7))
	    return(SNMP_NOSUCHOBJECT);
	if (!strncasecmp(typestr,"NOSUCHINSTANCE",7))
	    return(SNMP_NOSUCHINSTANCE);
	if (!strncasecmp(typestr,"UINTEGER",3))
	    return(TYPE_UINTEGER); /* historic - should not show up */
                                   /* but it does?                  */
	if (!strncasecmp(typestr, "NOTIF", 3))
		return(TYPE_NOTIFTYPE);
	if (!strncasecmp(typestr, "TRAP", 4))
		return(TYPE_TRAPTYPE);
        return(TYPE_UNKNOWN);
}

static int
__translate_asn_type(type)
int type;
{
   switch (type) {
        case ASN_INTEGER:
            return(TYPE_INTEGER);
	    break;
	case ASN_OCTET_STR:
            return(TYPE_OCTETSTR);
	    break;
	case ASN_OPAQUE:
            return(TYPE_OPAQUE);
	    break;
	case ASN_OBJECT_ID:
            return(TYPE_OBJID);
	    break;
	case ASN_TIMETICKS:
            return(TYPE_TIMETICKS);
	    break;
	case ASN_GAUGE:
            return(TYPE_GAUGE);
	    break;
	case ASN_COUNTER:
            return(TYPE_COUNTER);
	    break;
	case ASN_IPADDRESS:
            return(TYPE_IPADDR);
	    break;
	case ASN_BIT_STR:
            return(TYPE_BITSTRING);
	    break;
	case ASN_NULL:
            return(TYPE_NULL);
	    break;
	/* no translation for these exception type values */
	case SNMP_ENDOFMIBVIEW:
	case SNMP_NOSUCHOBJECT:
	case SNMP_NOSUCHINSTANCE:
	    return(type);
	    break;
	case ASN_UINTEGER:
            return(TYPE_UINTEGER);
	    break;
	case ASN_COUNTER64:
            return(TYPE_COUNTER64);
	    break;
	default:
            return(TYPE_OTHER);
            fprintf(stderr, "translate_asn_type: unhandled asn type (%d)\n",type);
            break;
        }
}

#define USE_BASIC 0
#define USE_ENUMS 1
#define USE_SPRINT_VALUE 2
static int
__snprint_value (buf, buf_len, var, tp, type, flag)
char * buf;
size_t buf_len;
netsnmp_variable_list * var;
struct tree * tp;
int type;
int flag;
{
   int len = 0;
   u_char* ip;
   struct enum_list *ep;


   buf[0] = '\0';
   if (flag == USE_SPRINT_VALUE) {
	snprint_value(buf, buf_len, var->name, var->name_length, var);
	len = STRLEN(buf);
   } else {
     switch (var->type) {
        case ASN_INTEGER:
           if (flag == USE_ENUMS) {
              for(ep = tp->enums; ep; ep = ep->next) {
                 if (ep->value == *var->val.integer) {
                    strcpy(buf, ep->label);
                    len = STRLEN(buf);
                    break;
                 }
              }
           }
           if (!len) {
              sprintf(buf,"%ld", *var->val.integer);
              len = STRLEN(buf);
           }
           break;

        case ASN_GAUGE:
        case ASN_COUNTER:
        case ASN_TIMETICKS:
        case ASN_UINTEGER:
           sprintf(buf,"%lu", (unsigned long) *var->val.integer);
           len = STRLEN(buf);
           break;

        case ASN_OCTET_STR:
        case ASN_OPAQUE:
           memcpy(buf, (char*)var->val.string, var->val_len);
           len = var->val_len;
           break;

        case ASN_IPADDRESS:
          ip = (u_char*)var->val.string;
          sprintf(buf, "%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
          len = STRLEN(buf);
          break;

        case ASN_NULL:
           break;

        case ASN_OBJECT_ID:
          __sprint_num_objid(buf, (oid *)(var->val.objid),
                             var->val_len/sizeof(oid));
          len = STRLEN(buf);
          break;

	case SNMP_ENDOFMIBVIEW:
          sprintf(buf,"%s", "ENDOFMIBVIEW");
	  break;
	case SNMP_NOSUCHOBJECT:
	  sprintf(buf,"%s", "NOSUCHOBJECT");
	  break;
	case SNMP_NOSUCHINSTANCE:
	  sprintf(buf,"%s", "NOSUCHINSTANCE");
	  break;

        case ASN_COUNTER64:
#ifdef OPAQUE_SPECIAL_TYPES
        case ASN_OPAQUE_COUNTER64:
        case ASN_OPAQUE_U64:
#endif
          printU64(buf,(struct counter64 *)var->val.counter64);
          len = STRLEN(buf);
          break;

#ifdef OPAQUE_SPECIAL_TYPES
        case ASN_OPAQUE_I64:
          printI64(buf,(struct counter64 *)var->val.counter64);
          len = STRLEN(buf);
          break;
#endif

        case ASN_BIT_STR:
            snprint_bitstring(buf, sizeof(buf), var, NULL, NULL, NULL);
            len = STRLEN(buf);
            break;
#ifdef OPAQUE_SPECIAL_TYPES
        case ASN_OPAQUE_FLOAT:
	  if (var->val.floatVal)
	    sprintf(buf,"%f", *var->val.floatVal);
         break;
         
        case ASN_OPAQUE_DOUBLE:
	  if (var->val.doubleVal)
	    sprintf(buf,"%f", *var->val.doubleVal);
         break;
#endif
         
        case ASN_NSAP:
        default:
	  fprintf(stderr,"snprint_value: asn type not handled %d\n",var->type);
     }
   }
   return(len);
}

static int
__sprint_num_objid (buf, objid, len)
char *buf;
oid *objid;
int len;
{
   int i;
   buf[0] = '\0';
   for (i=0; i < len; i++) {
	sprintf(buf,".%lu",*objid++);
	buf += STRLEN(buf);
   }
   return SUCCESS;
}

static int
__tp_sprint_num_objid (buf, tp)
char *buf;
SnmpMibNode *tp;
{
   oid newname[MAX_OID_LEN], *op;
   /* code taken from get_node in snmp_client.c */
   for (op = newname + MAX_OID_LEN - 1; op >= newname; op--) {
      *op = tp->subid;
      tp = tp->parent;
      if (tp == NULL) break;
   }
   return __sprint_num_objid(buf, op, newname + MAX_OID_LEN - op);
}

static int
__scan_num_objid (buf, objid, len)
char *buf;
oid *objid;
size_t *len;
{
   char *cp;
   *len = 0;
   if (*buf == '.') buf++;
   cp = buf;
   while (*buf) {
      if (*buf++ == '.') {
         sscanf(cp, "%lu", objid++);
         /* *objid++ = atoi(cp); */
         (*len)++;
         cp = buf;
      } else {