[thirdparty/bird.git] / filter / filter.c

/*
 *	Filters: utility functions
 *
 *	Copyright 1998 Pavel Machek <pavel@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 *
 *	FIXME: local namespace for functions
 *
 * 	Notice that pair is stored as integer: first << 16 | second
 */

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/signal.h>
#include <setjmp.h>

#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/socket.h"
#include "lib/string.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "conf/conf.h"
#include "filter/filter.h"

struct f_inst *startup_func = NULL;

#define runtime(x) do { \
    log( L_ERR x ); \
    res.type = T_RETURN; \
    res.val.i = F_ERROR; \
    return res; \
  } while(0)

#define ARG(x,y) \
	x = interpret(what->y); \
	if (x.type == T_RETURN) \
		return x;

#define ONEARG ARG(v1, a1.p)
#define TWOARGS ARG(v1, a1.p) \
		ARG(v2, a2.p)
#define TWOARGS_C TWOARGS \
                  if (v1.type != v2.type) \
		    runtime( "Can not operate with values of incompatible types" );

#define CMP_ERROR 999

/* Compare two values, returns -1, 0, 1 compared, ERROR 999 */
int
val_compare(struct f_val v1, struct f_val v2)
{
  if ((v1.type == T_VOID) && (v2.type == T_VOID))
    return 0;
  if (v1.type == T_VOID)	/* Hack for else */
    return -1;
  if (v2.type == T_VOID)
    return 1;

  if (v1.type != v2.type)
    return CMP_ERROR;
  switch (v1.type) {
  case T_INT: 
  case T_PAIR:
    if (v1.val.i == v2.val.i) return 0;
    if (v1.val.i < v2.val.i) return -1;
    return 1;
  case T_IP:
    return ipa_compare(v1.val.ip, v2.val.ip);
  default: { printf( "Error comparing\n" ); return CMP_ERROR; }
  }
}

int
val_in_range(struct f_val v1, struct f_val v2)
{
  if (((v1.type == T_INT) || (v1.type == T_IP)) && (v2.type == T_SET))
    return !! find_tree(v2.val.t, v1);
  return CMP_ERROR;
}

static void
tree_print(struct f_tree *t)
{
  if (!t) {
    printf( "() " );
    return;
  }
  printf( "[ " );
  tree_print( t->left );
  printf( ", " ); val_print( t->from ); printf( ".." ); val_print( t->to ); printf( ", " );
  tree_print( t->right );
  printf( "] " );
}

void
val_print(struct f_val v)
{
  char buf[2048];
#define PRINTF(a...) bsnprintf( buf, 2040, a )
  buf[0] = 0;
  switch (v.type) {
  case T_VOID: PRINTF( "(void)" ); break;
  case T_BOOL: PRINTF( v.val.i ? "TRUE" : "FALSE" ); break;
  case T_INT: PRINTF( "%d ", v.val.i ); break;
  case T_STRING: PRINTF( "%s", v.val.s ); break;
  case T_IP: PRINTF( "%I", v.val.ip ); break;
  case T_PREFIX: PRINTF( "%I/%d", v.val.px.ip, v.val.px.len ); break;
  case T_PAIR: PRINTF( "(%d,%d)", v.val.i >> 16, v.val.i & 0xffff ); break;
  case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
  default: PRINTF( "[unknown type %x]", v.type );
  }
  printf( buf );
}

static struct rte **f_rte;

static struct f_val interpret(struct f_inst *what);

static struct f_val
interpret(struct f_inst *what)
{
  struct symbol *sym;
  struct f_val v1, v2, res;
  int i,j,k;

  res.type = T_VOID;
  if (!what)
    return res;

  switch(what->code) {
  case ',':
    TWOARGS;
    break;

/* Binary operators */
  case '+':
    TWOARGS_C;
    switch (res.type = v1.type) {
    case T_VOID: runtime( "Can not operate with values of type void" );
    case T_INT: res.val.i = v1.val.i + v2.val.i; break;
    default: runtime( "Usage of unknown type" );
    }
    break;
  case '/':
    TWOARGS_C;
    switch (res.type = v1.type) {
    case T_VOID: runtime( "Can not operate with values of type void" );
    case T_INT: res.val.i = v1.val.i / v2.val.i; break;
    case T_IP: if (v2.type != T_INT)
                 runtime( "Operator / is <ip>/<int>" );
               break;
    default: runtime( "Usage of unknown type" );
    }
    break;

/* Relational operators */

#define COMPARE(x) \
    TWOARGS_C; \
    res.type = T_BOOL; \
    i = val_compare(v1, v2); \
    if (i==CMP_ERROR) \
      runtime( "Error in comparation" ); \
    res.val.i = (x); \
    break;

  case '!=': COMPARE(i!=0);
  case '==': COMPARE(i==0);
  case '<': COMPARE(i==-1);
  case '<=': COMPARE(i!=1);

    /* FIXME: Should be able to work with prefixes of limited sizes */
  case '~':
    TWOARGS;
    res.type = T_BOOL;
    res.val.i = val_in_range(v1, v2);
    if (res.val.i == CMP_ERROR)
      runtime( "~ applied on unknown type pair" );
    break;

  /* Set to indirect value, a1 = variable, a2 = value */
  case 's':
    ARG(v2, a2.p);
    sym = what->a1.p;
    switch (res.type = v2.type) {
    case T_VOID: runtime( "Can not assign void values" );
    case T_INT: 
    case T_IP: 
    case T_PREFIX: 
    case T_PAIR: 
      if (sym->class != (SYM_VARIABLE | v2.type))
	runtime( "Variable of bad type" );
      * (struct f_val *) sym->aux2 = v2; 
      break;
    default:
      bug( "Set to invalid type\n" );
    }
    break;

  case 'c':	/* integer (or simple type) constant */
    res.type = what->a1.i;
    res.val.i = what->a2.i;
    break;
  case 'C':
    res = * ((struct f_val *) what->a1.p);
    break;
  case 'p':
    ONEARG;
    val_print(v1);
    break;
  case '?':	/* ? has really strange error value, so we can implement if ... else nicely :-) */
    ONEARG;
    if (v1.type != T_BOOL)
      runtime( "If requires bool expression" );
    if (v1.val.i) {
      ARG(res,a2.p);
      res.val.i = 0;
    } else res.val.i = 1;
    res.type = T_BOOL;
    break;
  case '0':
    printf( "No operation\n" );
    break;
  case 'p,':
    ONEARG;
    if (what->a2.i != F_NONL)
      printf( "\n" );

    switch (what->a2.i) {
    case F_QUITBIRD:
      die( "Filter asked me to die" );
    case F_ACCEPT:
      /* Should take care about turning ACCEPT into MODIFY */
    case F_ERROR:
    case F_REJECT:
      res.type = T_RETURN;
      res.val.i = what->a1.i;
      break;
    case F_NONL:
    case F_NOP:
      break;
    default:
      bug( "unknown return type: can not happen");
    }
    break;
  case 'a':	/* rta access */
    {
      struct rta *rta = (*f_rte)->attrs;
      res.type = what->a1.i;
      switch(res.type) {
      case T_IP:
	res.val.ip = * (ip_addr *) ((char *) rta + what->a2.i);
	break;
      case T_PREFIX:	/* Warning: this works only for prefix of network */
	{
	  res.val.px.ip = (*f_rte)->net->n.prefix;
	  res.val.px.len = (*f_rte)->net->n.pxlen;
	  break;
	}
      default:
	bug( "Invalid type for rta access" );
      }
    }
    break;
  case 'cp':	/* Convert prefix to ... */
    ONEARG;
    if (v1.type != T_PREFIX)
      runtime( "Can not convert non-prefix this way" );
    res.type = what->a2.i;
    switch(res.type) {
    case T_INT:	res.val.i = v1.val.px.len; break;
    case T_IP: res.val.ip = v1.val.px.ip; break;
    default: bug( "Unknown prefix to conversion\n" );
    }
    break;
  case 'ca': /* CALL */
    ONEARG;
    res = interpret(what->a2.p);
    break;
  case 'SW':
    ONEARG;
    {
      struct f_tree *t = find_tree(what->a2.p, v1);
      if (!t) {
	v1.type = T_VOID;
	t = find_tree(what->a2.p, v1);
	if (!t) {
	  printf( "No else statement?\n ");
	  break;
	}
      }	
      if (!t->data)
	die( "Impossible: no code associated!\n" );
      return interpret(t->data);
    }
    break;
  case 'iM': /* IP.MASK(val) */
    TWOARGS_C;
    bug( "Should implement ip.mask\n" );
    break;
  default:
    bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
  }
  if (what->next)
    return interpret(what->next);
  return res;
}

int
f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool)
{
  struct f_inst *inst;
  struct f_val res;
  debug( "Running filter `%s'...", filter->name );

  f_rte = rte;
  inst = filter->root;
  res = interpret(inst);
  if (res.type != T_RETURN)
    return F_ERROR;
  debug( "done (%d)\n", res.val.i );
  return res.val.i;
}


void
filters_postconfig(void)
{
  struct f_val res;
  if (startup_func) {
    printf( "Launching startup function...\n" );
    res = interpret(startup_func);
    if (res.type == F_ERROR)
      die( "Startup function resulted in error." );
    printf( "done\n" );
  }
}
Commit	Line	Data
23b1539b PM	1	/*
	2	* Filters: utility functions
	3	*
	4	* Copyright 1998 Pavel Machek <pavel@ucw.cz>
	5	*
	6	* Can be freely distributed and used under the terms of the GNU GPL.
29818140 PM	7	*
29818140 PM	8	* FIXME: local namespace for functions
720d911d PM	9	*
720d911d PM	10	* Notice that pair is stored as integer: first << 16 \| second
23b1539b PM	11	*/
	12
	13	#include <stdio.h>
	14	#include <fcntl.h>
	15	#include <unistd.h>
	16	#include <sys/signal.h>
	17	#include <setjmp.h>
	18
	19	#include "nest/bird.h"
	20	#include "lib/lists.h"
	21	#include "lib/resource.h"
	22	#include "lib/socket.h"
38506f71	23	#include "lib/string.h"
23b1539b PM	24	#include "nest/route.h"
	25	#include "nest/protocol.h"
	26	#include "nest/iface.h"
	27	#include "conf/conf.h"
	28	#include "filter/filter.h"
	29
	30	struct f_inst *startup_func = NULL;
	31
	32	#define runtime(x) do { \
	33	log( L_ERR x ); \
	34	res.type = T_RETURN; \
	35	res.val.i = F_ERROR; \
	36	return res; \
	37	} while(0)
	38
	39	#define ARG(x,y) \
	40	x = interpret(what->y); \
	41	if (x.type == T_RETURN) \
	42	return x;
	43
2db3b288 PM	44	#define ONEARG ARG(v1, a1.p)
	45	#define TWOARGS ARG(v1, a1.p) \
	46	ARG(v2, a2.p)
23b1539b PM	47	#define TWOARGS_C TWOARGS \
	48	if (v1.type != v2.type) \
	49	runtime( "Can not operate with values of incompatible types" );
	50
38506f71 PM	51	#define CMP_ERROR 999
	52
	53	/* Compare two values, returns -1, 0, 1 compared, ERROR 999 */
	54	int
	55	val_compare(struct f_val v1, struct f_val v2)
	56	{
41be4444 PM	57	if ((v1.type == T_VOID) && (v2.type == T_VOID))
	58	return 0;
	59	if (v1.type == T_VOID) /* Hack for else */
	60	return -1;
	61	if (v2.type == T_VOID)
	62	return 1;
	63
7db7b7db PM	64	if (v1.type != v2.type)
7db7b7db PM	65	return CMP_ERROR;
38506f71 PM	66	switch (v1.type) {
38506f71 PM	67	case T_INT:
d3dd620b	68	case T_PAIR:
38506f71 PM	69	if (v1.val.i == v2.val.i) return 0;
	70	if (v1.val.i < v2.val.i) return -1;
	71	return 1;
43fc099b PM	72	case T_IP:
43fc099b PM	73	return ipa_compare(v1.val.ip, v2.val.ip);
41be4444	74	default: { printf( "Error comparing\n" ); return CMP_ERROR; }
38506f71 PM	75	}
	76	}
	77
7db7b7db PM	78	int
	79	val_in_range(struct f_val v1, struct f_val v2)
	80	{
	81	if (((v1.type == T_INT) \|\| (v1.type == T_IP)) && (v2.type == T_SET))
	82	return !! find_tree(v2.val.t, v1);
	83	return CMP_ERROR;
	84	}
	85
38506f71 PM	86	static void
	87	tree_print(struct f_tree *t)
	88	{
	89	if (!t) {
	90	printf( "() " );
	91	return;
	92	}
	93	printf( "[ " );
	94	tree_print( t->left );
	95	printf( ", " ); val_print( t->from ); printf( ".." ); val_print( t->to ); printf( ", " );
	96	tree_print( t->right );
	97	printf( "] " );
	98	}
	99
	100	void
	101	val_print(struct f_val v)
	102	{
	103	char buf[2048];
	104	#define PRINTF(a...) bsnprintf( buf, 2040, a )
	105	buf[0] = 0;
	106	switch (v.type) {
	107	case T_VOID: PRINTF( "(void)" ); break;
	108	case T_BOOL: PRINTF( v.val.i ? "TRUE" : "FALSE" ); break;
	109	case T_INT: PRINTF( "%d ", v.val.i ); break;
	110	case T_STRING: PRINTF( "%s", v.val.s ); break;
	111	case T_IP: PRINTF( "%I", v.val.ip ); break;
720d911d PM	112	case T_PREFIX: PRINTF( "%I/%d", v.val.px.ip, v.val.px.len ); break;
720d911d PM	113	case T_PAIR: PRINTF( "(%d,%d)", v.val.i >> 16, v.val.i & 0xffff ); break;
38506f71 PM	114	case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
	115	default: PRINTF( "[unknown type %x]", v.type );
	116	}
	117	printf( buf );
	118	}
	119
36bbfc70 PM	120	static struct rte **f_rte;
36bbfc70 PM	121
7db7b7db PM	122	static struct f_val interpret(struct f_inst *what);
7db7b7db PM	123
23b1539b PM	124	static struct f_val
	125	interpret(struct f_inst *what)
	126	{
	127	struct symbol *sym;
	128	struct f_val v1, v2, res;
38506f71	129	int i,j,k;
23b1539b PM	130
	131	res.type = T_VOID;
	132	if (!what)
	133	return res;
	134
	135	switch(what->code) {
	136	case ',':
	137	TWOARGS;
	138	break;
	139
	140	/* Binary operators */
	141	case '+':
	142	TWOARGS_C;
	143	switch (res.type = v1.type) {
	144	case T_VOID: runtime( "Can not operate with values of type void" );
	145	case T_INT: res.val.i = v1.val.i + v2.val.i; break;
	146	default: runtime( "Usage of unknown type" );
	147	}
	148	break;
	149	case '/':
	150	TWOARGS_C;
	151	switch (res.type = v1.type) {
	152	case T_VOID: runtime( "Can not operate with values of type void" );
	153	case T_INT: res.val.i = v1.val.i / v2.val.i; break;
	154	case T_IP: if (v2.type != T_INT)
	155	runtime( "Operator / is <ip>/<int>" );
	156	break;
	157	default: runtime( "Usage of unknown type" );
	158	}
	159	break;
	160
	161	/* Relational operators */
38506f71 PM	162
	163	#define COMPARE(x) \
	164	TWOARGS_C; \
	165	res.type = T_BOOL; \
	166	i = val_compare(v1, v2); \
	167	if (i==CMP_ERROR) \
	168	runtime( "Error in comparation" ); \
	169	res.val.i = (x); \
23b1539b	170	break;
38506f71 PM	171
	172	case '!=': COMPARE(i!=0);
	173	case '==': COMPARE(i==0);
	174	case '<': COMPARE(i==-1);
	175	case '<=': COMPARE(i!=1);
	176
29818140	177	/* FIXME: Should be able to work with prefixes of limited sizes */
38506f71 PM	178	case '~':
38506f71 PM	179	TWOARGS;
23b1539b	180	res.type = T_BOOL;
7db7b7db PM	181	res.val.i = val_in_range(v1, v2);
	182	if (res.val.i == CMP_ERROR)
	183	runtime( "~ applied on unknown type pair" );
23b1539b PM	184	break;
23b1539b PM	185
d3dd620b	186	/* Set to indirect value, a1 = variable, a2 = value */
23b1539b	187	case 's':
2db3b288 PM	188	ARG(v2, a2.p);
2db3b288 PM	189	sym = what->a1.p;
23b1539b PM	190	switch (res.type = v2.type) {
	191	case T_VOID: runtime( "Can not assign void values" );
	192	case T_INT:
d3dd620b PM	193	case T_IP:
	194	case T_PREFIX:
	195	case T_PAIR:
	196	if (sym->class != (SYM_VARIABLE \| v2.type))
23b1539b	197	runtime( "Variable of bad type" );
d3dd620b	198	* (struct f_val *) sym->aux2 = v2;
23b1539b	199	break;
d3dd620b PM	200	default:
d3dd620b PM	201	bug( "Set to invalid type\n" );
23b1539b PM	202	}
	203	break;
	204
d3dd620b	205	case 'c': /* integer (or simple type) constant */
2db3b288	206	res.type = what->a1.i;
d3dd620b	207	res.val.i = what->a2.i;
23b1539b	208	break;
38506f71 PM	209	case 'C':
	210	res = * ((struct f_val *) what->a1.p);
	211	break;
23b1539b PM	212	case 'p':
23b1539b PM	213	ONEARG;
38506f71	214	val_print(v1);
23b1539b PM	215	break;
	216	case '?': /* ? has really strange error value, so we can implement if ... else nicely :-) */
	217	ONEARG;
	218	if (v1.type != T_BOOL)
	219	runtime( "If requires bool expression" );
	220	if (v1.val.i) {
2db3b288	221	ARG(res,a2.p);
23b1539b PM	222	res.val.i = 0;
	223	} else res.val.i = 1;
	224	res.type = T_BOOL;
	225	break;
	226	case '0':
	227	printf( "No operation\n" );
	228	break;
	229	case 'p,':
	230	ONEARG;
d3dd620b PM	231	if (what->a2.i != F_NONL)
d3dd620b PM	232	printf( "\n" );
23b1539b	233
2db3b288	234	switch (what->a2.i) {
23b1539b PM	235	case F_QUITBIRD:
	236	die( "Filter asked me to die" );
	237	case F_ACCEPT:
	238	/* Should take care about turning ACCEPT into MODIFY */
	239	case F_ERROR:
	240	case F_REJECT:
	241	res.type = T_RETURN;
2db3b288	242	res.val.i = what->a1.i;
23b1539b	243	break;
d3dd620b	244	case F_NONL:
23b1539b PM	245	case F_NOP:
	246	break;
	247	default:
	248	bug( "unknown return type: can not happen");
	249	}
	250	break;
36bbfc70 PM	251	case 'a': /* rta access */
	252	{
	253	struct rta rta = (f_rte)->attrs;
	254	res.type = what->a1.i;
	255	switch(res.type) {
	256	case T_IP:
	257	res.val.ip = * (ip_addr ) ((char ) rta + what->a2.i);
	258	break;
	259	case T_PREFIX: /* Warning: this works only for prefix of network */
	260	{
	261	res.val.px.ip = (*f_rte)->net->n.prefix;
	262	res.val.px.len = (*f_rte)->net->n.pxlen;
	263	break;
	264	}
	265	default:
	266	bug( "Invalid type for rta access" );
	267	}
	268	}
	269	break;
	270	case 'cp': /* Convert prefix to ... */
	271	ONEARG;
	272	if (v1.type != T_PREFIX)
	273	runtime( "Can not convert non-prefix this way" );
	274	res.type = what->a2.i;
	275	switch(res.type) {
	276	case T_INT: res.val.i = v1.val.px.len; break;
	277	case T_IP: res.val.ip = v1.val.px.ip; break;
	278	default: bug( "Unknown prefix to conversion\n" );
	279	}
	280	break;
6542ece9 PM	281	case 'ca': /* CALL */
	282	ONEARG;
	283	res = interpret(what->a2.p);
	284	break;
41be4444	285	case 'SW':
7db7b7db	286	ONEARG;
41be4444 PM	287	{
	288	struct f_tree *t = find_tree(what->a2.p, v1);
	289	if (!t) {
	290	v1.type = T_VOID;
	291	t = find_tree(what->a2.p, v1);
	292	if (!t) {
	293	printf( "No else statement?\n ");
	294	break;
	295	}
	296	}
	297	if (!t->data)
	298	die( "Impossible: no code associated!\n" );
	299	return interpret(t->data);
	300	}
7db7b7db	301	break;
d3dd620b PM	302	case 'iM': /* IP.MASK(val) */
	303	TWOARGS_C;
	304	bug( "Should implement ip.mask\n" );
	305	break;
23b1539b PM	306	default:
	307	bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
	308	}
	309	if (what->next)
	310	return interpret(what->next);
	311	return res;
	312	}
	313
	314	int
	315	f_run(struct filter filter, struct rte rte, struct ea_list tmp_attrs, struct linpool tmp_pool)
	316	{
	317	struct f_inst *inst;
	318	struct f_val res;
	319	debug( "Running filter `%s'...", filter->name );
	320
36bbfc70	321	f_rte = rte;
23b1539b PM	322	inst = filter->root;
	323	res = interpret(inst);
	324	if (res.type != T_RETURN)
	325	return F_ERROR;
	326	debug( "done (%d)\n", res.val.i );
	327	return res.val.i;
	328	}
	329
	330
	331	void
	332	filters_postconfig(void)
	333	{
	334	struct f_val res;
8ba2cc06 PM	335	if (startup_func) {
8ba2cc06 PM	336	printf( "Launching startup function...\n" );
23b1539b	337	res = interpret(startup_func);
bad631e0	338	if (res.type == F_ERROR)
8ba2cc06 PM	339	die( "Startup function resulted in error." );
	340	printf( "done\n" );
	341	}
23b1539b	342	}