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|
/*
* lib/route/cls/ematch_syntax.y ematch expression syntax
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2010 Thomas Graf <tgraf@suug.ch>
*/
%{
#include <netlink-local.h>
#include <netlink-tc.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink/route/pktloc.h>
#include <netlink/route/cls/ematch.h>
#include <netlink/route/cls/ematch/cmp.h>
#include <netlink/route/cls/ematch/nbyte.h>
#include <netlink/route/cls/ematch/text.h>
%}
%error-verbose
%define api.pure
%name-prefix "ematch_"
%parse-param {void *scanner}
%parse-param {char **errp}
%parse-param {struct nl_list_head *root}
%lex-param {void *scanner}
%union {
struct tcf_em_cmp cmp;
struct ematch_quoted q;
struct rtnl_ematch * e;
struct rtnl_pktloc * loc;
uint32_t i;
char * s;
}
%{
extern int ematch_lex(YYSTYPE *, void *);
static void yyerror(void *scanner, char **errp, struct nl_list_head *root, const char *msg)
{
if (msg)
asprintf(errp, "%s", msg);
}
%}
%token <i> ERROR LOGIC NOT OPERAND NUMBER ALIGN LAYER
%token <i> KW_OPEN "("
%token <i> KW_CLOSE ")"
%token <i> KW_PLUS "+"
%token <i> KW_MASK "mask"
%token <i> KW_AT "at"
%token <i> EMATCH_CMP "cmp"
%token <i> EMATCH_NBYTE "pattern"
%token <i> EMATCH_TEXT "text"
%token <i> KW_EQ "="
%token <i> KW_GT ">"
%token <i> KW_LT "<"
%token <i> KW_FROM "from"
%token <i> KW_TO "to"
%token <s> STR
%token <q> QUOTED
%type <i> mask align operand
%type <e> expr match ematch
%type <cmp> cmp_expr cmp_match
%type <loc> pktloc text_from text_to
%type <q> pattern
%destructor { free($$); NL_DBG(2, "string destructor\n"); } <s>
%destructor { rtnl_pktloc_put($$); NL_DBG(2, "pktloc destructor\n"); } <loc>
%destructor { free($$.data); NL_DBG(2, "quoted destructor\n"); } <q>
%start input
%%
input:
/* empty */
| expr
{
nl_list_add_tail(root, &$1->e_list);
}
;
expr:
match
{
$$ = $1;
}
| match LOGIC expr
{
rtnl_ematch_set_flags($1, $2);
/* make ematch new head */
nl_list_add_tail(&$1->e_list, &$3->e_list);
$$ = $1;
}
;
match:
NOT ematch
{
rtnl_ematch_set_flags($2, TCF_EM_INVERT);
$$ = $2;
}
| ematch
{
$$ = $1;
}
;
ematch:
/* CMP */
cmp_match
{
struct rtnl_ematch *e;
if (!(e = rtnl_ematch_alloc())) {
asprintf(errp, "Unable to allocate ematch object");
YYABORT;
}
if (rtnl_ematch_set_kind(e, TCF_EM_CMP) < 0)
BUG();
rtnl_ematch_cmp_set(e, &$1);
$$ = e;
}
| EMATCH_NBYTE "(" pktloc KW_EQ pattern ")"
{
struct rtnl_ematch *e;
if (!(e = rtnl_ematch_alloc())) {
asprintf(errp, "Unable to allocate ematch object");
YYABORT;
}
if (rtnl_ematch_set_kind(e, TCF_EM_NBYTE) < 0)
BUG();
rtnl_ematch_nbyte_set_offset(e, $3->layer, $3->offset);
rtnl_pktloc_put($3);
rtnl_ematch_nbyte_set_pattern(e, (uint8_t *) $5.data, $5.index);
$$ = e;
}
| EMATCH_TEXT "(" STR QUOTED text_from text_to ")"
{
struct rtnl_ematch *e;
if (!(e = rtnl_ematch_alloc())) {
asprintf(errp, "Unable to allocate ematch object");
YYABORT;
}
if (rtnl_ematch_set_kind(e, TCF_EM_TEXT) < 0)
BUG();
rtnl_ematch_text_set_algo(e, $3);
rtnl_ematch_text_set_pattern(e, $4.data, $4.index);
if ($5) {
rtnl_ematch_text_set_from(e, $5->layer, $5->offset);
rtnl_pktloc_put($5);
}
if ($6) {
rtnl_ematch_text_set_to(e, $6->layer, $6->offset);
rtnl_pktloc_put($6);
}
$$ = e;
}
/* CONTAINER */
| "(" expr ")"
{
struct rtnl_ematch *e;
if (!(e = rtnl_ematch_alloc())) {
asprintf(errp, "Unable to allocate ematch object");
YYABORT;
}
if (rtnl_ematch_set_kind(e, TCF_EM_CONTAINER) < 0)
BUG();
/* Make e->childs the list head of a the ematch sequence */
nl_list_add_tail(&e->e_childs, &$2->e_list);
$$ = e;
}
;
/*
* CMP match
*
* match := cmp(expr) | expr
* expr := pktloc (=|>|<) NUMBER
* pktloc := alias | definition
*
*/
cmp_match:
EMATCH_CMP "(" cmp_expr ")"
{ $$ = $3; }
| cmp_expr
{ $$ = $1; }
;
cmp_expr:
pktloc operand NUMBER
{
if ($1->align == TCF_EM_ALIGN_U16 ||
$1->align == TCF_EM_ALIGN_U32)
$$.flags = TCF_EM_CMP_TRANS;
memset(&$$, 0, sizeof($$));
$$.mask = $1->mask;
$$.off = $1->offset;
$$.align = $1->align;
$$.layer = $1->layer;
$$.opnd = $2;
$$.val = $3;
rtnl_pktloc_put($1);
}
;
text_from:
/* empty */
{ $$ = NULL; }
| "from" pktloc
{ $$ = $2; }
;
text_to:
/* empty */
{ $$ = NULL; }
| "to" pktloc
{ $$ = $2; }
;
/*
* pattern
*/
pattern:
QUOTED
{
$$ = $1;
}
| STR
{
struct nl_addr *addr;
if (nl_addr_parse($1, AF_UNSPEC, &addr) == 0) {
$$.len = nl_addr_get_len(addr);
$$.index = min_t(int, $$.len, nl_addr_get_prefixlen(addr)/8);
if (!($$.data = calloc(1, $$.len))) {
nl_addr_put(addr);
YYABORT;
}
memcpy($$.data, nl_addr_get_binary_addr(addr), $$.len);
nl_addr_put(addr);
} else {
asprintf(errp, "invalid pattern \"%s\"", $1);
YYABORT;
}
}
;
/*
* packet location
*/
pktloc:
STR
{
struct rtnl_pktloc *loc;
if (rtnl_pktloc_lookup($1, &loc) < 0) {
asprintf(errp, "Packet location \"%s\" not found", $1);
YYABORT;
}
$$ = loc;
}
/* [u8|u16|u32|NUM at] LAYER + OFFSET [mask MASK] */
| align LAYER "+" NUMBER mask
{
struct rtnl_pktloc *loc;
if ($5 && (!$1 || $1 > TCF_EM_ALIGN_U32)) {
asprintf(errp, "mask only allowed for alignments u8|u16|u32");
YYABORT;
}
if (!(loc = rtnl_pktloc_alloc())) {
asprintf(errp, "Unable to allocate packet location object");
YYABORT;
}
loc->name = strdup("<USER-DEFINED>");
loc->align = $1;
loc->layer = $2;
loc->offset = $4;
loc->mask = $5;
$$ = loc;
}
;
align:
/* empty */
{ $$ = 0; }
| ALIGN "at"
{ $$ = $1; }
| NUMBER "at"
{ $$ = $1; }
;
mask:
/* empty */
{ $$ = 0; }
| "mask" NUMBER
{ $$ = $2; }
;
operand:
KW_EQ
{ $$ = TCF_EM_OPND_EQ; }
| KW_GT
{ $$ = TCF_EM_OPND_GT; }
| KW_LT
{ $$ = TCF_EM_OPND_LT; }
;
|