source: libpacketdump/parser.y @ fab1d42

%{
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <netinet/in.h>
    #include <sys/socket.h>
    #include <arpa/inet.h>
    #include <assert.h>
    #include "grammar.h"
    #include "libpacketdump.h"
    #include "bitbuffer.h"

    #define YYERROR_VERBOSE 1

    
    int yylex(void);

    char *file;
    element_t *el_list = NULL;

    /* i didnt want these to be global, but i think they have to be? :/ */
    static bitbuffer_t buffer = 0;
    static int bits = 0;
%}


%union {
    int intval;
    char *textval;
    element_t *ptr;
}

%token TOK_BIGENDIAN TOK_LITTLEENDIAN TOK_NEXT TOK_OUTPUT_INT TOK_OUTPUT_HEX TOK_OUTPUT_IPV4 TOK_OUTPUT_FLAG TOK_CONSTANT TOK_IDENTIFIER TOK_OUTPUT_MAC TOK_OUTPUT_NONE

%type <intval> TOK_BIGENDIAN TOK_LITTLEENDIAN TOK_NEXT TOK_OUTPUT_INT TOK_OUTPUT_HEX TOK_OUTPUT_IPV4 TOK_OUTPUT_FLAG TOK_OUTPUT_NONE TOK_CONSTANT output byteorder size '"'
%type <textval> TOK_IDENTIFIER identifier
%type <ptr> element nextfile elements

%%

config:     elements nextfile { /*print_list(el_list);*/ }
           ;
        
elements:   element 
          | elements element { }
          ;

element:    byteorder size output identifier { 
                node_t *n;
                element_t *el;
                /* create a new field node... */
                field_t *new_field = (field_t *)malloc(sizeof(field_t)); 
                new_field->order = $1;
                new_field->size = $2;
                new_field->display = $3;
                new_field->identifier = $4;

                /* to go inside a new node... */
                n = (node_t *)malloc(sizeof(node_t));
                n->field = new_field;

                /* to go inside a new element */
                el = (element_t *)malloc(sizeof(element_t));            
                el->type = FIELD;
                el->next = NULL;
                el->data = n;
                
                /* and stick the new element on the end of our list */
                el_list = append(el_list, el);
            }
          ;

byteorder: TOK_BIGENDIAN { $$ = BIGENDIAN; }
            | TOK_LITTLEENDIAN { $$ = LITTLEENDIAN; }
          ;

size:   TOK_CONSTANT { $$ = yylval.intval; }
        ;

output:   TOK_OUTPUT_HEX    { $$ = DISPLAY_HEX; }
        | TOK_OUTPUT_INT    { $$ = DISPLAY_INT; }
        | TOK_OUTPUT_IPV4   { $$ = DISPLAY_IPV4; }
        | TOK_OUTPUT_FLAG   { $$ = DISPLAY_FLAG; }
        | TOK_OUTPUT_MAC    { $$ = DISPLAY_MAC; }
        | TOK_OUTPUT_NONE   { $$ = DISPLAY_NONE; }
        ;


identifier: TOK_IDENTIFIER { $$ = strdup($1); }
            ;


nextfile:   TOK_NEXT identifier identifier { 

                element_t *tmp;
                node_t *n;
                element_t *el;
                next_t *nextheader = (next_t *)malloc(sizeof(next_t)); 
                nextheader->prefix = $2;
                nextheader->fieldname = $3;
                nextheader->target = NULL;
                
                for(tmp = el_list ;; tmp=tmp->next)
                {
                    /* 
                     * if we hit the end of the list or a nextheader then
                     * the field name we are looking for doesn't exist
                     * - this is an error but we can carry on and just
                     * not bother parsing anything after this header
                     */
                    if(tmp == NULL || tmp->type == NEXTHEADER)
                    {
                        fprintf(stderr, "XXX No field match found for "
                                        "nextfield '%s'...ignoring\n", $3);
                        $$ = NULL;
                        break;
                    }
                    
                    /* 
                     * if the field name matches the one we are looking at,
                     * store a pointer to it so we can steal its value later
                     */
                    if(strcmp($3, tmp->data->field->identifier) == 0)
                    {
                        nextheader->target = tmp->data->field;
                        break;
                    }
                }
                
                n = (node_t *)malloc(sizeof(node_t));
                n->nextheader = nextheader;

                el = (element_t *)malloc(sizeof(element_t));            
                el->type = NEXTHEADER;
                el->next = NULL;
                el->data = n;
                
                el_list = append(el_list, el);
            }
        |   { /*printf("no next file...\n");*/ $$ = NULL; }
        ;


%%