header_complex.c

snmp的源代码,已经在我的ubuntu下编译通过

        *var_len = sizeof(long);

    for (nptr = datalist; nptr != NULL && found == NULL; nptr = nptr->next) {
        if (vp) {
            memcpy(indexOid, vp->name, vp->namelen * sizeof(oid));
            memcpy(indexOid + vp->namelen, nptr->name,
                   nptr->namelen * sizeof(oid));
            len = vp->namelen + nptr->namelen;
        } else {
            memcpy(indexOid, nptr->name, nptr->namelen * sizeof(oid));
            len = nptr->namelen;
        }
        result = snmp_oid_compare(name, *length, indexOid, len);
        DEBUGMSGTL(("header_complex", "Checking: "));
        DEBUGMSGOID(("header_complex", indexOid, len));
        DEBUGMSG(("header_complex", "\n"));

        if (exact) {
            if (result == 0) {
                found = nptr;
            }
        } else {
            if (result == 0) {
                /*
                 * found an exact match.  Need the next one for !exact 
                 */
                if (nptr->next)
                    found = nptr->next;
            } else if (result == -1) {
                found = nptr;
            }
        }
    }
    if (found) {
        if (vp) {
            memcpy(name, vp->name, vp->namelen * sizeof(oid));
            memcpy(name + vp->namelen, found->name,
                   found->namelen * sizeof(oid));
            *length = vp->namelen + found->namelen;
        } else {
            memcpy(name, found->name, found->namelen * sizeof(oid));
            *length = found->namelen;
        }
        return found->data;
    }

    return NULL;
}

struct header_complex_index *
header_complex_add_data(struct header_complex_index **thedata,
                        netsnmp_variable_list * var, void *data)
{
    oid             newoid[MAX_OID_LEN];
    size_t          newoid_len;
    struct header_complex_index *ret;

    if (thedata == NULL || var == NULL || data == NULL)
        return NULL;

    header_complex_generate_oid(newoid, &newoid_len, NULL, 0, var);
    ret =
        header_complex_add_data_by_oid(thedata, newoid, newoid_len, data);
    /*
     * free the variable list, but not the enclosed data!  it's not ours! 
     */
    snmp_free_varbind(var);
    return (ret);
}

struct header_complex_index *
header_complex_add_data_by_oid(struct header_complex_index **thedata,
                               oid * newoid, size_t newoid_len, void *data)
{
    struct header_complex_index *hciptrn, *hciptrp, *ourself;

    if (thedata == NULL || newoid == NULL || data == NULL)
        return NULL;

    for (hciptrn = *thedata, hciptrp = NULL;
         hciptrn != NULL; hciptrp = hciptrn, hciptrn = hciptrn->next)
        /*
         * XXX: check for == and error (overlapping table entries) 
         */
        if (snmp_oid_compare
            (hciptrn->name, hciptrn->namelen, newoid, newoid_len)
            > 0)
            break;

    /*
     * nptr should now point to the spot that we need to add ourselves
     * in front of, and pptr should be our new 'prev'. 
     */

    /*
     * create ourselves 
     */
    ourself = (struct header_complex_index *)
        SNMP_MALLOC_STRUCT(header_complex_index);

    /*
     * change our pointers 
     */
    ourself->prev = hciptrp;
    ourself->next = hciptrn;

    if (ourself->next)
        ourself->next->prev = ourself;

    if (ourself->prev)
        ourself->prev->next = ourself;

    ourself->data = data;
    ourself->name = snmp_duplicate_objid(newoid, newoid_len);
    ourself->namelen = newoid_len;

    /*
     * rewind to the head of the list and return it (since the new head
     * could be us, we need to notify the above routine who the head now is. 
     */
    for (hciptrp = ourself; hciptrp->prev != NULL;
         hciptrp = hciptrp->prev);

    *thedata = hciptrp;
    DEBUGMSGTL(("header_complex_add_data", "adding something...\n"));

    return hciptrp;
}

/*
 * extracts an entry from the storage space (removing it from future
 * accesses) and returns the data stored there
 * 
 * Modifies "thetop" pointer as needed (and if present) if were
 * extracting the first node.
 */

void           *
header_complex_extract_entry(struct header_complex_index **thetop,
                             struct header_complex_index *thespot)
{
    struct header_complex_index *hciptrp, *hciptrn;
    void           *retdata = thespot->data;

    if (thespot == NULL) {
        DEBUGMSGTL(("header_complex_extract_entry",
                    "Null pointer asked to be extracted\n"));
        return NULL;
    }

    hciptrp = thespot->prev;
    hciptrn = thespot->next;

    if (hciptrp)
        hciptrp->next = hciptrn;
    else if (thetop)
        *thetop = hciptrn;

    if (hciptrn)
        hciptrn->prev = hciptrp;

    if (thespot->name)
        free(thespot->name);

    free(thespot);
    return retdata;
}

/*
 * wipe out a single entry 
 */
void
header_complex_free_entry(struct header_complex_index *theentry,
                          HeaderComplexCleaner * cleaner)
{
    void           *data;
    data = header_complex_extract_entry(NULL, theentry);
    (*cleaner) (data);
}

/*
 * completely wipe out all entries in our data store 
 */
void
header_complex_free_all(struct header_complex_index *thestuff,
                        HeaderComplexCleaner * cleaner)
{
    struct header_complex_index *hciptr, *hciptrn;

    for (hciptr = thestuff; hciptr != NULL; hciptr = hciptrn) {
        hciptrn = hciptr->next; /* need to extract this before deleting it */
        header_complex_free_entry(hciptr, cleaner);
    }
}

struct header_complex_index *
header_complex_find_entry(struct header_complex_index *thestuff,
                          void *theentry)
{
    struct header_complex_index *hciptr;

    for (hciptr = thestuff; hciptr != NULL && hciptr->data != theentry;
         hciptr = hciptr->next);
    return hciptr;
}

#ifdef TESTING

void
header_complex_dump(struct header_complex_index *thestuff)
{
    struct header_complex_index *hciptr;
    oid             oidsave[MAX_OID_LEN];
    size_t          len;

    for (hciptr = thestuff; hciptr != NULL; hciptr = hciptr->next) {
        DEBUGMSGTL(("header_complex_dump", "var:  "));
        header_complex_generate_oid(oidsave, &len, NULL, 0, hciptr->);
        DEBUGMSGOID(("header_complex_dump", oidsave, len));
        DEBUGMSG(("header_complex_dump", "\n"));
    }
}

main()
{
    oid             oidsave[MAX_OID_LEN];
    int             len = MAX_OID_LEN, len2;
    netsnmp_variable_list *vars;
    long            ltmp = 4242, ltmp2 = 88, ltmp3 = 1, ltmp4 = 4200;
    oid             ourprefix[] = { 1, 2, 3, 4 };
    oid             testparse[] = { 4, 116, 101, 115, 116, 4200 };
    int             ret;

    char           *string = "wes", *string2 = "dawn", *string3 = "test";

    struct header_complex_index *thestorage = NULL;

    debug_register_tokens("header_complex");
    snmp_set_do_debugging(1);

    vars = NULL;
    len2 = sizeof(ltmp);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_INTEGER, (char *) &ltmp,
                              len2);
    header_complex_add_data(&thestorage, vars, ourprefix);

    vars = NULL;
    len2 = strlen(string);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_OCTET_STR, string, len2);
    header_complex_add_data(&thestorage, vars, ourprefix);

    vars = NULL;
    len2 = sizeof(ltmp2);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_INTEGER, (char *) &ltmp2,
                              len2);
    header_complex_add_data(&thestorage, vars, ourprefix);

    vars = NULL;
    len2 = strlen(string2);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_OCTET_STR, string2,
                              len2);
    header_complex_add_data(&thestorage, vars, ourprefix);

    vars = NULL;
    len2 = sizeof(ltmp3);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_INTEGER, (char *) &ltmp3,
                              len2);
    header_complex_add_data(&thestorage, vars, ourprefix);

    vars = NULL;
    len2 = strlen(string3);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_OCTET_STR, string3,
                              len2);
    len2 = sizeof(ltmp4);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_INTEGER, (char *) &ltmp4,
                              len2);
    header_complex_add_data(&thestorage, vars, ourprefix);

    header_complex_dump(thestorage);

    vars = NULL;
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_OCTET_STR, NULL, 0);
    snmp_varlist_add_variable(&vars, NULL, 0, ASN_INTEGER, NULL, 0);
    ret =
        header_complex_parse_oid(testparse,
                                 sizeof(testparse) / sizeof(oid), vars);
    DEBUGMSGTL(("header_complex_test", "parse returned %d...\n", ret));

}
#endif