parse.c

snmp up 2

 * Takes a list of the form:
 * { iso org(3) dod(6) 1 }
 * and creates several nodes, one for each parent-child pair.
 * Returns 0 on error.
 */
static int
getoid(FILE * fp, struct subid_s *id,   /* an array of subids */
       int length)
{                               /* the length of the array */
    register int    count;
    int             type;
    char            token[MAXTOKEN];

    if ((type = get_token(fp, token, MAXTOKEN)) != LEFTBRACKET) {
        print_error("Expected \"{\"", token, type);
        return 0;
    }
    type = get_token(fp, token, MAXTOKEN);
    for (count = 0; count < length; count++, id++) {
        id->label = NULL;
        id->modid = current_module;
        id->subid = -1;
        if (type == RIGHTBRACKET)
            return count;
        if (type == LABEL) {
            /*
             * this entry has a label 
             */
            id->label = strdup(token);
            type = get_token(fp, token, MAXTOKEN);
            if (type == LEFTPAREN) {
                type = get_token(fp, token, MAXTOKEN);
                if (type == NUMBER) {
                    id->subid = strtoul(token, NULL, 10);
                    if ((type =
                         get_token(fp, token, MAXTOKEN)) != RIGHTPAREN) {
                        print_error("Expected a closing parenthesis",
                                    token, type);
                        return 0;
                    }
                } else {
                    print_error("Expected a number", token, type);
                    return 0;
                }
            } else {
                continue;
            }
        } else if (type == NUMBER) {
            /*
             * this entry  has just an integer sub-identifier 
             */
            id->subid = strtoul(token, NULL, 10);
        } else {
            print_error("Expected label or number", token, type);
            return 0;
        }
        type = get_token(fp, token, MAXTOKEN);
    }
    print_error("Too long OID", token, type);
    return 0;
}

/*
 * Parse a sequence of object subidentifiers for the given name.
 * The "label OBJECT IDENTIFIER ::=" portion has already been parsed.
 *
 * The majority of cases take this form :
 * label OBJECT IDENTIFIER ::= { parent 2 }
 * where a parent label and a child subidentifier number are specified.
 *
 * Variations on the theme include cases where a number appears with
 * the parent, or intermediate subidentifiers are specified by label,
 * by number, or both.
 *
 * Here are some representative samples :
 * internet        OBJECT IDENTIFIER ::= { iso org(3) dod(6) 1 }
 * mgmt            OBJECT IDENTIFIER ::= { internet 2 }
 * rptrInfoHealth  OBJECT IDENTIFIER ::= { snmpDot3RptrMgt 0 4 }
 *
 * Here is a very rare form :
 * iso             OBJECT IDENTIFIER ::= { 1 }
 *
 * Returns NULL on error.  When this happens, memory may be leaked.
 */
static struct node *
parse_objectid(FILE * fp, char *name)
{
    register int    count;
    register struct subid_s *op, *nop;
    int             length;
    struct subid_s  loid[32];
    struct node    *np, *root = NULL, *oldnp = NULL;
    struct tree    *tp;

    if ((length = getoid(fp, loid, 32)) == 0) {
        print_error("Bad object identifier", NULL, CONTINUE);
        return NULL;
    }

    /*
     * Handle numeric-only object identifiers,
     *  by labelling the first sub-identifier
     */
    op = loid;
    if (!op->label)
        for (tp = tree_head; tp; tp = tp->next_peer)
            if ((int) tp->subid == op->subid) {
                op->label = strdup(tp->label);
                break;
            }

    /*
     * Handle  "label OBJECT-IDENTIFIER ::= { subid }"
     */
    if (length == 1) {
        op = loid;
        np = alloc_node(op->modid);
        if (np == NULL)
            return (NULL);
        np->subid = op->subid;
        np->label = strdup(name);
        np->parent = op->label;
        return np;
    }

    /*
     * For each parent-child subid pair in the subid array,
     * create a node and link it into the node list.
     */
    for (count = 0, op = loid, nop = loid + 1; count < (length - 1);
         count++, op++, nop++) {
        /*
         * every node must have parent's name and child's name or number 
         */
        /*
         * XX the next statement is always true -- does it matter ?? 
         */
        if (op->label && (nop->label || (nop->subid != -1))) {
            np = alloc_node(nop->modid);
            if (np == NULL)
                return (NULL);
            if (root == NULL)
                root = np;

            np->parent = strdup(op->label);
            if (count == (length - 2)) {
                /*
                 * The name for this node is the label for this entry 
                 */
                np->label = strdup(name);
            } else {
                if (!nop->label) {
                    nop->label = (char *) malloc(20 + ANON_LEN);
                    if (nop->label == NULL)
                        return (NULL);
                    sprintf(nop->label, "%s%d", ANON, anonymous++);
                }
                np->label = strdup(nop->label);
            }
            if (nop->subid != -1)
                np->subid = nop->subid;
            else
                print_error("Warning: This entry is pretty silly",
                            np->label, CONTINUE);

            /*
             * set up next entry 
             */
            if (oldnp)
                oldnp->next = np;
            oldnp = np;
        }                       /* end if(op->label... */
    }

    /*
     * free the loid array 
     */
    for (count = 0, op = loid; count < length; count++, op++) {
        if (op->label)
            free(op->label);
    }

    return root;
}

static int
get_tc(const char *descriptor,
       int modid,
       int *tc_index,
       struct enum_list **ep, struct range_list **rp, char **hint)
{
    int             i;
    struct tc      *tcp;

    i = get_tc_index(descriptor, modid);
    if (tc_index)
        *tc_index = i;
    if (i != -1) {
        tcp = &tclist[i];
        if (ep) {
            free_enums(ep);
            *ep = copy_enums(tcp->enums);
        }
        if (rp) {
            free_ranges(rp);
            *rp = copy_ranges(tcp->ranges);
        }
        if (hint) {
            if (*hint)
                free(*hint);
            *hint = (tcp->hint ? strdup(tcp->hint) : NULL);
        }
        return tcp->type;
    }
    return LABEL;
}

/*
 * return index into tclist of given TC descriptor
 * return -1 if not found
 */
static int
get_tc_index(const char *descriptor, int modid)
{
    int             i;
    struct tc      *tcp;
    struct module  *mp;
    struct module_import *mip;

    /*
     * Check that the descriptor isn't imported
     *  by searching the import list
     */

    for (mp = module_head; mp; mp = mp->next)
        if (mp->modid == modid)
            break;
    if (mp)
        for (i = 0, mip = mp->imports; i < mp->no_imports; ++i, ++mip) {
            if (!label_compare(mip->label, descriptor)) {
                /*
                 * Found it - so amend the module ID 
                 */
                modid = mip->modid;
                break;
            }
        }


    for (i = 0, tcp = tclist; i < MAXTC; i++, tcp++) {
        if (tcp->type == 0)
            break;
        if (!label_compare(descriptor, tcp->descriptor) &&
            ((modid == tcp->modid) || (modid == -1))) {
            return i;
        }
    }
    return -1;
}

/*
 * translate integer tc_index to string identifier from tclist
 * *
 * * Returns pointer to string in table (should not be modified) or NULL
 */
const char     *
get_tc_descriptor(int tc_index)
{
    if (tc_index < 0 || tc_index >= MAXTC)
        return NULL;
    return (tclist[tc_index].descriptor);
}


/*
 * Parses an enumeration list of the form:
 *        { label(value) label(value) ... }
 * The initial { has already been parsed.
 * Returns NULL on error.
 */

static struct enum_list *
parse_enumlist(FILE * fp, struct enum_list **retp)
{
    register int    type;
    char            token[MAXTOKEN];
    struct enum_list *ep = NULL, **epp = &ep;

    free_enums(retp);

    while ((type = get_token(fp, token, MAXTOKEN)) != ENDOFFILE) {
        if (type == RIGHTBRACKET)
            break;
        if (type == LABEL) {
            /*
             * this is an enumerated label 
             */
            *epp =
                (struct enum_list *) calloc(1, sizeof(struct enum_list));
            if (*epp == NULL)
                return (NULL);
            /*
             * a reasonable approximation for the length 
             */
            (*epp)->label = strdup(token);
            type = get_token(fp, token, MAXTOKEN);
            if (type != LEFTPAREN) {
                print_error("Expected \"(\"", token, type);
                return NULL;
            }
            type = get_token(fp, token, MAXTOKEN);
            if (type != NUMBER) {
                print_error("Expected integer", token, type);
                return NULL;
            }
            (*epp)->value = strtol(token, NULL, 10);
            type = get_token(fp, token, MAXTOKEN);
            if (type != RIGHTPAREN) {
                print_error("Expected \")\"", token, type);
                return NULL;
            }
            epp = &(*epp)->next;
        }
    }
    if (type == ENDOFFILE) {
        print_error("Expected \"}\"", token, type);
        return NULL;
    }
    *retp = ep;
    return ep;
}

static struct range_list *
parse_ranges(FILE * fp, struct range_list **retp)
{
    int             low, high;
    char            nexttoken[MAXTOKEN];
    int             nexttype;
    struct range_list *rp = NULL, **rpp = &rp;
    int             size = 0, taken = 1;

    free_ranges(retp);

    nexttype = get_token(fp, nexttoken, MAXTOKEN);
    if (nexttype == SIZE) {
        size = 1;
        taken = 0;
        nexttype = get_token(fp, nexttoken, MAXTOKEN);
        if (nexttype != LEFTPAREN)
            print_error("Expected \"(\" after SIZE", nexttoken, nexttype);
    }

    do {
        if (!taken)
            nexttype = get_token(fp, nexttoken, MAXTOKEN);
        else
            taken = 0;
        high = low = strtol(nexttoken, NULL, 10);
        nexttype = get_token(fp, nexttoken, MAXTOKEN);
        if (nexttype == RANGE) {
            nexttype = get_token(fp, nexttoken, MAXTOKEN);
            high = strtol(nexttoken, NULL, 10);
            nexttype = get_token(fp, nexttoken, MAXTOKEN);
        }
        *rpp = (struct range_list *) calloc(1, sizeof(struct range_list));
        if (*rpp == NULL)
            break;
        (*rpp)->low = low;
        (*rpp)->high = high;
        rpp = &(*rpp)->next;

    } while (nexttype == BAR);
    if (size) {
        if (nexttype != RIGHTPAREN)
            print_error("Expected \")\" after SIZE", nexttoken, nexttype);
        nexttype = get_token(fp, nexttoken, nexttype);
    }
    if (nexttype != RIGHTPAREN)
        print_error("Expected \")\"", nexttoken, nexttype);

    *retp = rp;
    return rp;
}

/*
 * Parses an asn type.  Structures are ignored by this parser.
 * Returns NULL on error.
 */
static struct node *
parse_asntype(FILE * fp, char *name, int *ntype, char *ntoken)
{
    int             type, i;
    char            token[MAXTOKEN];
    char            quoted_string_buffer[MAXQUOTESTR];
    char           *hint = NULL;
    struct tc      *tcp;
    int             level;

    type = get_token(fp, token, MAXTOKEN);
    if (type == SEQUENCE || type == CHOICE) {
        level = 0;
        while ((type = get_token(fp, token, MAXTOKEN)) != ENDOFFILE) {
            if (type == LEFTBRACKET) {
                level++;
            } else if (type == RIGHTBRACKET && --level == 0) {
                *ntype = get_token(fp, ntoken, MAXTOKEN);
                return NULL;
            }
        }
        print_error("Expected \"}\"", token, type);
        return NULL;
    } else if (type == LEFTBRACKET) {
        struct node    *np;
        int             ch_next = '{';
        ungetc(ch_next, fp);
        np = parse_objectid(fp, name);
        if (np != NULL) {
            *ntype = get_token(fp, ntoken, MAXTOKEN);
            return np;
        }
        return NULL;
    } else if (type == LEFTSQBRACK) {
        int             size = 0;
        do {
            type = get_token(fp, token, MAXTOKEN);
        } while (type != ENDOFFILE && type != RIGHTSQBRACK);
        if (type != RIGHTSQBRACK) {
            print_error("Expected \"]\"", token, type);
            return NULL;
        }
        type = get_token(fp, token, MAXTOKEN);
        if (type == IMPLICIT)
            type = get_token(fp, token, MAXTOKEN);
        *ntype = get_token(fp, ntoken, MAXTOKEN);
        if (*ntype == LEFTPAREN) {
            switch (type) {
            case OCTETSTR:
                *ntype = get_token(fp, ntoken, MAXTOKEN);
                if (*ntype != SIZE) {