bird/conf/confbase.Y
2000-06-03 18:23:00 +00:00

187 lines
4.1 KiB
Text

/*
* BIRD -- Configuration Parser Top
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Parser
*
* Both the configuration and CLI commands are analysed using a syntax
* driven parser generated by the |bison| tool from a grammar which
* is constructed from information gathered from grammar snippets by
* the |gen_parser.m4| script.
*
* Grammar snippets are files (usually with extension |.Y|) contributed
* by various BIRD modules to provide information about syntax of their
* configuration and their CLI commands. Each snipped consists of several
* section, each of them starting with a special keyword: |CF_HDR| for
* a list of |#include| directives needed by the C code, |CF_DEFINES|
* for a list of C declarations, |CF_DECLS| for |bison| declarations
* including keyword definitions specified as |CF_KEYWORDS|, |CF_GRAMMAR|
* for the grammar rules, |CF_CODE| for auxillary C code and finally
* |CF_END| at the end of the snippet.
*
* To create references between the snippets, it's possible to define
* multi-part rules by utilizing the |CF_ADDTO| macro which adds a new
* alternative to a multi-part rule.
*
* CLI commands are defined using a |CF_CLI| macro. Its parameters are:
* the list of keywords determining the command, the list of paramaters,
* help text for the parameters and help text for the command.
*
* Values of |enum| filter types can be defined using |CF_ENUM| with
* the following parameters: name of filter type, prefix common for all
* literals of this type, names of all the possible values.
*/
CF_HDR
#include "nest/bird.h"
#include "conf/conf.h"
#include "lib/resource.h"
#include "lib/socket.h"
#include "lib/timer.h"
#include "lib/string.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "nest/route.h"
#include "nest/cli.h"
#include "filter/filter.h"
/* FIXME: Turn on YYERROR_VERBOSE and work around lots of bison bugs? */
CF_DECLS
%union {
int i;
u32 i32;
ip_addr a;
struct symbol *s;
char *t;
struct rtable_config *r;
struct f_inst *x;
struct filter *f;
struct f_tree *e;
struct f_val v;
struct f_path_mask *h;
struct password_item *p;
struct rt_show_data *ra;
void *g;
bird_clock_t time;
struct prefix px;
}
%token END CLI_MARKER INVALID_TOKEN
%token GEQ LEQ NEQ AND OR
%token <i> NUM ENUM
%token <i32> RTRID
%token <a> IPA
%token <s> SYM
%token <t> TEXT
%type <i> expr bool pxlen
%type <time> datetime
%type <a> ipa
%type <px> prefix prefix_or_ipa
%nonassoc PREFIX_DUMMY
%nonassoc '=' '<' '>' '~' '.' GEQ LEQ NEQ AND OR
%left '+' '-'
%left '*' '/' '%'
%left '!'
CF_KEYWORDS(DEFINE, ON, OFF, YES, NO)
CF_GRAMMAR
/* Basic config file structure */
config: conf_entries END { return 0; }
| CLI_MARKER cli_cmd { return 0; }
;
conf_entries:
/* EMPTY */
| conf_entries conf
;
CF_ADDTO(conf, ';')
/* Constant expressions */
expr:
NUM
| '(' term ')' { $$ = f_eval_int($2); }
| SYM { if ($1->class != SYM_NUMBER) cf_error("Number expected"); else $$ = $1->aux; }
;
CF_ADDTO(conf, definition)
definition:
DEFINE SYM '=' expr ';' {
cf_define_symbol($2, SYM_NUMBER, NULL);
$2->aux = $4;
}
| DEFINE SYM '=' IPA ';' {
cf_define_symbol($2, SYM_IPA, cfg_alloc(sizeof(ip_addr)));
*(ip_addr *)$2->def = $4;
}
;
/* Switches */
bool:
expr {$$ = !!$1; }
| ON { $$ = 1; }
| YES { $$ = 1; }
| OFF { $$ = 0; }
| NO { $$ = 0; }
| /* Silence means agreement */ { $$ = 1; }
;
/* Addresses, prefixes and netmasks */
ipa:
IPA
| SYM {
if ($1->class != SYM_IPA) cf_error("IP address expected");
$$ = *(ip_addr *)$1->def;
}
;
prefix:
ipa pxlen {
if (!ip_is_prefix($1, $2)) cf_error("Invalid prefix");
$$.addr = $1; $$.len = $2;
}
;
prefix_or_ipa:
prefix
| ipa { $$.addr = $1; $$.len = BITS_PER_IP_ADDRESS; }
;
pxlen:
'/' expr {
if ($2 < 0 || $2 > BITS_PER_IP_ADDRESS) cf_error("Invalid prefix length %d", $2);
$$ = $2;
}
| ':' ipa {
$$ = ipa_mklen($2);
if ($$ < 0) cf_error("Invalid netmask %I", $2);
}
;
datetime:
TEXT {
$$ = tm_parse_date($1);
if (!$$)
cf_error("Invalid date");
}
;
CF_CODE
CF_END