smux.c

snmp的源代码,已经在我的ubuntu下编译通过

     */
    len = SMUXMAXPKTSIZE;
    DEBUGMSGTL(("smux",
                "[smux_parse_var] Asn coded len of var %d, type %d\n",
                var_val_len, (int) *vartype));

    switch ((short) *vartype) {
    case ASN_INTEGER:
        *varlength = sizeof(long);
        asn_parse_int(var_val, &len, vartype,
                      (long *) &smux_long, *varlength);
        return (u_char *) & smux_long;
        break;
    case ASN_COUNTER:
    case ASN_GAUGE:
    case ASN_TIMETICKS:
    case ASN_UINTEGER:
        *varlength = sizeof(u_long);
        asn_parse_unsigned_int(var_val, &len, vartype,
                               (u_long *) & smux_ulong, *varlength);
        return (u_char *) & smux_ulong;
        break;
    case ASN_COUNTER64:
        *varlength = sizeof(smux_counter64);
        asn_parse_unsigned_int64(var_val, &len, vartype,
                                 (struct counter64 *) &smux_counter64,
                                 *varlength);
        return (u_char *) & smux_counter64;
        break;
    case ASN_IPADDRESS:
        *varlength = 4;
        /*
         * consume the tag and length, but just copy here
         * because we know it is an ip address
         */
        if ((var_val = asn_parse_header(var_val, &len, &type)) == NULL)
            return NULL;
        memcpy((u_char *) & (smux_sa.sin_addr.s_addr), var_val,
               *varlength);
        return (u_char *) & (smux_sa.sin_addr.s_addr);
        break;
    case ASN_OCTET_STR:
        /*
         * XXX 
         */
        if (len == 0)
            return NULL;
        str_len = SMUXMAXSTRLEN;
        asn_parse_string(var_val, &len, vartype, smux_str, &str_len);
        *varlength = str_len;
        return smux_str;
        break;
    case ASN_OPAQUE:
    case ASN_NSAP:
    case ASN_OBJECT_ID:
        objid_len = MAX_OID_LEN;
        asn_parse_objid(var_val, &len, vartype, smux_objid, &objid_len);
        *varlength = objid_len * sizeof(oid);
        return (u_char *) smux_objid;
        break;
    case SNMP_NOSUCHOBJECT:
    case SNMP_NOSUCHINSTANCE:
    case SNMP_ENDOFMIBVIEW:
    case ASN_NULL:
        return NULL;
        break;
    case ASN_BIT_STR:
        /*
         * XXX 
         */
        if (len == 0)
            return NULL;
        str_len = SMUXMAXSTRLEN;
        asn_parse_bitstring(var_val, &len, vartype, smux_str, &str_len);
        *varlength = str_len;
        return (u_char *) smux_str;
        break;
    default:
        snmp_log(LOG_ERR, "bad type returned (%x)\n", *vartype);
        return NULL;
        break;
    }
}

/*
 * XXX This is a bad hack - do not want to muck with ucd code 
 */
static int
smux_build(u_char type,
           u_long reqid,
           oid * objid,
           size_t * oidlen,
           u_char val_type,
           u_char * val, size_t val_len, u_char * packet, size_t * length)
{
    u_char         *ptr, *save1, *save2;
    size_t          len;
    long            errstat = 0;
    long            errindex = 0;

    /*
     * leave space for Seq and length 
     */
    save1 = packet;
    ptr = packet + 4;
    len = *length - 4;

    /*
     * build reqid 
     */
    ptr = asn_build_unsigned_int(ptr, &len,
                                 (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
                                           ASN_INTEGER), &reqid,
                                 sizeof(reqid));
    if (ptr == NULL) {
        return -1;
    }

    /*
     * build err stat 
     */
    ptr = asn_build_int(ptr, &len,
                        (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
                                  ASN_INTEGER), &errstat, sizeof(errstat));
    if (ptr == NULL) {
        return -1;
    }

    /*
     * build err index 
     */
    ptr = asn_build_int(ptr, &len,
                        (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
                                  ASN_INTEGER), &errindex,
                        sizeof(errindex));
    if (ptr == NULL) {
        return -1;
    }

    save2 = ptr;
    ptr += 4;
    len -= 4;

    if (type != SMUX_SET) {
        val_type = ASN_NULL;
        val_len = 0;
    }

    /*
     * build var list : snmp_build_var_op not liked by gated XXX 
     */
    ptr = snmp_build_var_op(ptr, objid, oidlen, val_type, val_len,
                            val, &len);
    if (ptr == NULL) {
        return -1;
    }

    len = ptr - save1;
    asn_build_sequence(save1, &len, type, (ptr - save1 - 4));

    len = ptr - save2;
    asn_build_sequence(save2, &len,
                       (ASN_SEQUENCE | ASN_CONSTRUCTOR),
                       (ptr - save2 - 4));

    *length = ptr - packet;

    return 0;
}

static void
smux_peer_cleanup(int sd)
{
    smux_reg       *nrptr, *rptr, *rptr2;
    int             nfound, i;

    nfound = 0;

    /*
     * close the descriptor 
     */
    close(sd);

    /*
     * delete all of the passive registrations that this peer owns 
     */
    for (rptr = PassiveRegs; rptr; rptr = nrptr) {
        nrptr = rptr->sr_next;
        if (rptr->sr_fd == sd) {
            smux_list_detach(&PassiveRegs, &rptr);
            free(rptr);
        }
        rptr = nrptr;
    }
    /*
     * find replacements for all of the active registrations found 
     */
    for (rptr = ActiveRegs; rptr; rptr = rptr2) {
        rptr2 = rptr->sr_next;
        if (rptr->sr_fd == sd) {
            smux_list_detach(&ActiveRegs, &rptr);
            unregister_mib(rptr->sr_name, rptr->sr_name_len);
            if ((nrptr = smux_find_replacement(rptr->sr_name,
                                               rptr->sr_name_len)) !=
                NULL) {
                smux_list_detach(&PassiveRegs, &nrptr);
                smux_list_add(&ActiveRegs, nrptr);
                register_mib("smux", (struct variable *)
                             smux_variables, sizeof(struct variable2),
                             1, nrptr->sr_name, nrptr->sr_name_len);
            }
            free(rptr);
        }
    }

    /*
     * decrement the peer count 
     */
    npeers--;

    /*
     * make his auth available again 
     */
    for (i = 0; i < nauths; i++) {
        if (Auths[i]->sa_active_fd == sd) {
            char            oid_name[128];
            Auths[i]->sa_active_fd = -1;
            snprint_objid(oid_name, sizeof(oid_name), Auths[i]->sa_oid,
                          Auths[i]->sa_oid_len);
            snmp_log(LOG_INFO, "peer disconnected: %s\n", oid_name);
        }
    }
}

int
smux_send_rrsp(int sd, int pri)
{
    u_char          outdata[2 + sizeof(int)];
    u_char         *ptr = outdata;
    int             intsize = sizeof(int);
    u_int           mask = ((u_int) 0xFF) << (8 * (sizeof(int) - 1));
    /*
     * e.g. mask is 0xFF000000 on a 32-bit machine 
     */
    int             sent;

    /*
     * This is kind of like calling asn_build_int(), but the
     * encoding will always be the size of an integer on this
     * machine, never shorter.
     */
    *ptr++ = (u_char) SMUX_RRSP;
    *ptr++ = (u_char) intsize;

    /*
     * Copy each byte, most significant first. 
     */
    while (intsize--) {
        *ptr++ = (u_char) ((pri & mask) >> (8 * (sizeof(int) - 1)));
        pri <<= 8;
    }

    sent = send(sd, (char *) outdata, sizeof outdata, 0);
    if (sent < 0) {
        DEBUGMSGTL(("smux", "[smux_send_rrsp] send failed\n"));
    }
    return (sent);
}

static u_char  *
smux_trap_process(u_char * rsp, size_t * len)
{
    oid             sa_enterpriseoid[MAX_OID_LEN], var_name[MAX_OID_LEN];
    size_t          datalen, var_name_len, var_val_len, maxlen;
    size_t          sa_enterpriseoid_len;
    u_char          vartype, *ptr, *var_val;

    long            trap, specific;
    u_long          timestamp;

    netsnmp_variable_list *snmptrap_head, *snmptrap_ptr, *snmptrap_tmp;
    snmptrap_head = NULL;
    snmptrap_ptr = NULL;

    ptr = rsp;

    /*
     * parse the sub-agent enterprise oid 
     */
    sa_enterpriseoid_len = MAX_OID_LEN;
    if ((ptr = asn_parse_objid(ptr, len,
                               &vartype, (oid *) & sa_enterpriseoid,
                               &sa_enterpriseoid_len)) == NULL) {
        DEBUGMSGTL(("smux",
                    "[smux_trap_process] asn_parse_objid failed\n"));
        return NULL;
    }

    /*
     * parse the agent-addr ipAddress 
     */
    datalen = SMUXMAXSTRLEN;
    if (((ptr = asn_parse_string(ptr, len,
                                 &vartype, smux_str,
                                 &datalen)) == NULL) ||
        (vartype != (u_char) ASN_IPADDRESS)) {
        DEBUGMSGTL(("smux",
                    "[smux_trap_process] asn_parse_string failed\n"));
        return NULL;
    }

    /*
     * parse the generic trap int 
     */
    datalen = sizeof(long);
    if ((ptr = asn_parse_int(ptr, len, &vartype, &trap, datalen)) == NULL) {
        DEBUGMSGTL(("smux",
                    "[smux_trap_process] asn_parse_int generic failed\n"));
        return NULL;
    }

    /*
     * parse the specific trap int 
     */
    datalen = sizeof(long);
    if ((ptr = asn_parse_int(ptr, len,
                             &vartype, &specific, datalen)) == NULL) {
        DEBUGMSGTL(("smux",
                    "[smux_trap_process] asn_parse_int specific failed\n"));
        return NULL;
    }

    /*
     * parse the timeticks timestamp 
     */
    datalen = sizeof(u_long);
    if (((ptr = asn_parse_unsigned_int(ptr, len,
                                       &vartype, (u_long *) & timestamp,
                                       datalen)) == NULL) ||
        (vartype != (u_char) ASN_TIMETICKS)) {
        DEBUGMSGTL(("smux",
                    "[smux_trap_process] asn_parse_unsigned_int (timestamp) failed\n"));
        return NULL;
    }

    /*
     * parse out the overall sequence 
     */
    ptr = asn_parse_header(ptr, len, &vartype);
    if (ptr == NULL || vartype != (ASN_SEQUENCE | ASN_CONSTRUCTOR)) {
        return NULL;
    }

    /*
     * parse the variable bindings 
     */
    while (ptr && *len) {

        /*
         * get the objid and the asn1 coded value 
         */
        var_name_len = MAX_OID_LEN;
        ptr = snmp_parse_var_op(ptr, var_name, &var_name_len, &vartype,
                                &var_val_len, (u_char **) & var_val, len);

        if (ptr == NULL) {
            return NULL;
        }

        maxlen = SMUXMAXPKTSIZE;
        switch ((short) vartype) {
        case ASN_INTEGER:
            var_val_len = sizeof(long);
            asn_parse_int(var_val, &maxlen, &vartype,
                          (long *) &smux_long, var_val_len);
            var_val = (u_char *) & smux_long;
            break;
        case ASN_COUNTER:
        case ASN_GAUGE:
        case ASN_TIMETICKS:
        case ASN_UINTEGER:
            var_val_len = sizeof(u_long);
            asn_parse_unsigned_int(var_val, &maxlen, &vartype,
                                   (u_long *) & smux_ulong, var_val_len);
            var_val = (u_char *) & smux_ulong;
            break;
        case ASN_COUNTER64:
            var_val_len = sizeof(smux_counter64);
            asn_parse_unsigned_int64(var_val, &maxlen, &vartype,
                                     (struct counter64 *) &smux_counter64,
                                     var_val_len);
            var_val = (u_char *) & smux_counter64;
            break;
        case ASN_IPADDRESS:
            var_val_len = 4;
            /*
             * consume the tag and length, but just copy here
             * because we know it is an ip address
             */
            if ((var_val =
                 asn_parse_header(var_val, &maxlen, &vartype)) == NULL)
                return NULL;
            memcpy((u_char *) & (smux_sa.sin_addr.s_addr), var_val,
                   var_val_len);
            var_val = (u_char *) & (smux_sa.sin_addr.s_addr);
            break;
        case ASN_OPAQUE:
        case ASN_OCTET_STR:
            /*
             * XXX 
             */
            if (len == 0)
                return NULL;
            var_val_len = SMUXMAXSTRLEN;
            asn_parse_string(var_val, &maxlen, &vartype,
                             smux_str, &var_val_len);
            var_val = smux_str;
            break;
        case ASN_OBJECT_ID:
            var_val_len = MAX_OID_LEN;
            asn_parse_objid(var_val, &maxlen, &vartype,
                            smux_objid, &var_val_len);
            var_val_len *= sizeof(oid);
            var_val = (u_char *) smux_objid;
            break;
        case SNMP_NOSUCHOBJECT:
        case SNMP_NOSUCHINSTANCE:
        case SNMP_ENDOFMIBVIEW:
        case ASN_NULL:
            var_val = NULL;
            break;
        case ASN_BIT_STR:
            /*
             * XXX 
             */
            if (len == 0)
                return NULL;
            var_val_len = SMUXMAXSTRLEN;
            asn_parse_bitstring(var_val, &maxlen, &vartype,
                                smux_str, &var_val_len);
            var_val = (u_char *) smux_str;
            break;
        case ASN_NSAP:
        default:
            snmp_log(LOG_ERR, "bad type returned (%x)\n", vartype);
            var_val = NULL;
            break;
        }

        snmptrap_tmp =
            (netsnmp_variable_list *)
            malloc(sizeof(netsnmp_variable_list));
        if (snmptrap_tmp == NULL)
            return NULL;
        memset(snmptrap_tmp, 0, sizeof(netsnmp_variable_list));
        if (snmptrap_head == NULL) {
            snmptrap_head = snmptrap_tmp;
            snmptrap_ptr = snmptrap_head;
        } else {
            snmptrap_ptr->next_variable = snmptrap_tmp;
            snmptrap_ptr = snmptrap_ptr->next_variable;
        }

        snmp_set_var_objid(snmptrap_ptr, var_name, var_name_len);
        snmp_set_var_value(snmptrap_ptr, (char *) var_val, var_val_len);
        snmptrap_ptr->type = vartype;
        snmptrap_ptr->next_variable = NULL;

    }

    /*
     * send the traps 
     */
    send_enterprise_trap_vars(trap, specific, (oid *) & sa_enterpriseoid,
                              sa_enterpriseoid_len, snmptrap_head);

    /*
     * free trap variables 
     */
    snmp_free_varbind(snmptrap_head);

    return ptr;

}