From d4d7562806b7306d6e5ed9b759906e264b743dc5 Mon Sep 17 00:00:00 2001 From: Pavel Machek Date: Thu, 2 Mar 2000 22:23:18 +0000 Subject: Avoid being exponential, do not allow ! = --- filter/config.Y | 41 ++++++++++++++++++++--------------------- filter/filter.c | 14 ++++++++++---- filter/test.conf | 2 +- 3 files changed, 31 insertions(+), 26 deletions(-) diff --git a/filter/config.Y b/filter/config.Y index c4633fc..dc7cc5a 100644 --- a/filter/config.Y +++ b/filter/config.Y @@ -8,10 +8,7 @@ FIXME (nonurgent): define keyword FIXME (for BGP): whole system of paths, path ~ string, path.prepend(), path.originate FIXME: create community lists - FIXME: '! =' should not be permitted. Ze `!=' by nemelo byt totez jako `! =' Nadefinujes si pres %token novy token a do cf-lex.l pridas nove pravidlo, ktere jej rozpoznava. Napriklad != return NEQ; FIXME: IP addresses in ipv6 - - FIXME: how can functions return value? */ CF_HDR @@ -42,6 +39,8 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, CONST, UNSET, RETURN, %nonassoc THEN %nonassoc ELSE +%token GEQ LEQ NEQ + %type term block cmds cmd function_body constant print_one print_list var_list var_listn dynamic_attr function_call %type filter filter_body where_filter %type type break_command pair @@ -56,7 +55,7 @@ filter_def: FILTER SYM { cf_push_scope( $2 ); } filter_body { cf_define_symbol($2, SYM_FILTER, $4); $4->name = $2->name; - printf( "We have new filter defined (%s)\n", $2->name ); + DBG( "We have new filter defined (%s)\n", $2->name ); cf_pop_scope(); } ; @@ -81,7 +80,7 @@ type: one_decl: type SYM { cf_define_symbol($2, SYM_VARIABLE | $1, NULL); - printf( "New variable %s type %x\n", $2->name, $1 ); + DBG( "New variable %s type %x\n", $2->name, $1 ); $2->aux = 0; { struct f_val * val; @@ -109,7 +108,6 @@ declsn: one_decl { $$ = $1; } } ; - filter_body: function_body { struct filter *f = cfg_alloc(sizeof(struct filter)); @@ -152,7 +150,7 @@ where_filter: ; function_params: - '(' declsn ')' { printf( "Have function parameters\n" ); $$=$2; } + '(' declsn ')' { DBG( "Have function parameters\n" ); $$=$2; } | '(' ')' { $$=NULL; } ; @@ -164,14 +162,14 @@ function_body: CF_ADDTO(conf, function_def) function_def: - FUNCTION SYM { printf( "Begining of function %s\n", $2->name ); cf_push_scope($2); } function_params function_body { + FUNCTION SYM { DBG( "Begining of function %s\n", $2->name ); cf_push_scope($2); } function_params function_body { extern struct f_inst *startup_func; cf_define_symbol($2, SYM_FUNCTION, $5); if (!strcasecmp($2->name, "startup")) startup_func = $5; $2->aux = (int) $4; $2->aux2 = $5; - printf("Hmm, we've got one function here - %s\n", $2->name); + DBG("Hmm, we've got one function here - %s\n", $2->name); cf_pop_scope(); } ; @@ -263,7 +261,7 @@ constant: | pair { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_PAIR; $$->a2.i = $1; } | ipa { NEW_F_VAL; $$ = f_new_inst(); $$->code = 'C'; $$->a1.p = val; *val = $1; } | prefix_s {NEW_F_VAL; $$ = f_new_inst(); $$->code = 'C'; $$->a1.p = val; *val = $1; } - | '[' set_items ']' { printf( "We've got a set here..." ); $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_SET; $$->a2.p = build_tree($2); printf( "ook\n" ); } + | '[' set_items ']' { DBG( "We've got a set here..." ); $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_SET; $$->a2.p = build_tree($2); DBG( "ook\n" ); } | ENUM { $$ = f_new_inst(); $$->code = 'c'; $$->aux = $1 >> 16; $$->a2.i = $1 & 0xffff; } ; @@ -283,7 +281,7 @@ function_call: struct f_inst *inst = $3; if ($1->class != SYM_FUNCTION) cf_error("You can not call something which is not function. Really."); - printf("You are calling function %s\n", $1->name); + DBG("You are calling function %s\n", $1->name); $$ = f_new_inst(); $$->code = P('c','a'); $$->a1.p = inst; @@ -292,7 +290,7 @@ function_call: while (sym || inst) { if (!sym || !inst) cf_error("wrong number of arguments for function %s.", $1->name); - printf( "You should pass parameter called %s\n", sym->name); + DBG( "You should pass parameter called %s\n", sym->name); inst->a1.p = sym; sym = (void *) sym->aux; inst = inst->next; @@ -300,17 +298,18 @@ function_call: } ; +/* NEQ, LEQ and GEQ are responsible for 42 shift/reduce conflicts */ term: '(' term ')' { $$ = $2; } - | term '+' term { $$ = f_new_inst(); $$->code = '+'; $$->a1.p = $1; $$->a2.p = $3; } + | term '+' term { $$ = f_new_inst(); $$->code = '+'; $$->a1.p = $1; $$->a2.p = $3; } | term '=' term { $$ = f_new_inst(); $$->code = P('=','='); $$->a1.p = $1; $$->a2.p = $3; } - | term '!' '=' term { $$ = f_new_inst(); $$->code = P('!','='); $$->a1.p = $1; $$->a2.p = $4; } - | term '<' term { $$ = f_new_inst(); $$->code = '<'; $$->a1.p = $1; $$->a2.p = $3; } - | term '<' '=' term { $$ = f_new_inst(); $$->code = P('<','='); $$->a1.p = $1; $$->a2.p = $4; } - | term '>' term { $$ = f_new_inst(); $$->code = '<'; $$->a1.p = $3; $$->a2.p = $1; } - | term '>' '=' term { $$ = f_new_inst(); $$->code = P('<','='); $$->a1.p = $4; $$->a2.p = $1; } - | term '~' term { $$ = f_new_inst(); $$->code = '~'; $$->a1.p = $1; $$->a2.p = $3; } + | term NEQ term { $$ = f_new_inst(); $$->code = P('!','='); $$->a1.p = $1; $$->a2.p = $3; } + | term '<' term { $$ = f_new_inst(); $$->code = '<'; $$->a1.p = $1; $$->a2.p = $3; } + | term LEQ term { $$ = f_new_inst(); $$->code = P('<','='); $$->a1.p = $1; $$->a2.p = $3; } + | term '>' term { $$ = f_new_inst(); $$->code = '<'; $$->a1.p = $3; $$->a2.p = $1; } + | term GEQ term { $$ = f_new_inst(); $$->code = P('<','='); $$->a1.p = $3; $$->a2.p = $1; } + | term '~' term { $$ = f_new_inst(); $$->code = '~'; $$->a1.p = $1; $$->a2.p = $3; } | DEFINED '(' term ')' { $$ = f_new_inst(); $$->code = P('d','e'); $$->a1.p = $3; } | constant { $$ = $1; } @@ -404,7 +403,7 @@ cmd: } | SYM '=' term ';' { $$ = f_new_inst(); - printf( "Ook, we'll set value\n" ); + DBG( "Ook, we'll set value\n" ); if (($1->class & ~T_MASK) != SYM_VARIABLE) cf_error( "You may only set variables, and this is %x.\n", $1->class ); $$->code = 's'; @@ -413,7 +412,7 @@ cmd: } | RETURN term ';' { $$ = f_new_inst(); - printf( "Ook, we'll return the value\n" ); + DBG( "Ook, we'll return the value\n" ); $$->code = 'r'; $$->a1.p = $2; } diff --git a/filter/filter.c b/filter/filter.c index f0de20d..7e52664 100644 --- a/filter/filter.c +++ b/filter/filter.c @@ -446,14 +446,16 @@ interpret(struct f_inst *what) int i_same(struct f_inst *f1, struct f_inst *f2) { - if (!f1) - return 1; if ((!!f1) != (!!f2)) return 0; + if (!f1) + return 1; if (f1->aux != f2->aux) return 0; if (f1->code != f2->code) return 0; + if (f1 == f2) /* It looks strange, but it is possible with call rewriting trickery */ + return 1; switch(f1->code) { case ',': /* fall through */ @@ -495,8 +497,12 @@ i_same(struct f_inst *f1, struct f_inst *f2) case 'r': ONEARG; break; case P('c','p'): ONEARG; break; - case P('c','a'): /* CALL, FIXME: exponential in some cases */ - ONEARG; if (!i_same(f1->a2.p, f2->a2.p)) return 0; break; + case P('c','a'): /* Call rewriting trickery to avoid exponential behaviour */ + ONEARG; + if (!i_same(f1->a2.p, f2->a2.p)) + return 0; + f2->a2.p = f1->a2.p; + break; case P('S','W'): ONEARG; if (!same_tree(f1->a2.p, f2->a2.p)) return 0; break; case P('i','M'): TWOARGS; break; default: diff --git a/filter/test.conf b/filter/test.conf index e42fead..22dba29 100644 --- a/filter/test.conf +++ b/filter/test.conf @@ -44,7 +44,7 @@ ip p; if 1234 = i then printn "."; else { print "*** FAIL: if 1 else"; } if 1 <= 1 then printn "."; else { print "*** FAIL: test 3"; } if 1234 < 1234 then { print "*** FAIL: test 4"; quitbird; } else print "ok"; - print " data types; must be true: " 1.2.3.4 = 1.2.3.4 "," 1 ~ [1,2,3] "," 5 ~ [1..20] "," 2 ~ [ 1, 2, 3 ] "," 5 ~ [ 4 .. 7 ] "," 1.2.3.4 ~ [ 1.2.3.3..1.2.3.5 ] "," 1.2.3.4 ~ 1.0.0.0/8 "," 1.0.0.0/8 ~ 1.0.0.0/8 "," 1.0.0.0/8 ~ [ 1.0.0.0/8+ ] "," 1.2.0.0/16 ~ [ 1.0.0.0/8{ 15 , 16 } ] "," defined(1) "," defined(1.2.3.4); + print " data types; must be true: " 1.2.3.4 = 1.2.3.4 "," 1 ~ [1,2,3] "," 5 ~ [1..20] "," 2 ~ [ 1, 2, 3 ] "," 5 ~ [ 4 .. 7 ] "," 1.2.3.4 ~ [ 1.2.3.3..1.2.3.5 ] "," 1.2.3.4 ~ 1.0.0.0/8 "," 1.0.0.0/8 ~ 1.0.0.0/8 "," 1.0.0.0/8 ~ [ 1.0.0.0/8+ ] "," 1.2.0.0/16 ~ [ 1.0.0.0/8{ 15 , 16 } ] "," defined(1) "," defined(1.2.3.4) "," 1 != 2 "," 1 <= 2; print " data types: must be false: " 1 ~ [ 2, 3, 4 ] "," 5 ~ [ 2, 3, 4, 7..11 ] "," 1.2.3.4 ~ [ 1.2.3.3, 1.2.3.5 ] "," (1,2) > (2,2) "," (1,1) > (1,1) "," 1.0.0.0/8 ~ [ 1.0.0.0/8- ] "," 1.2.0.0/17 ~ [ 1.0.0.0/8{ 15 , 16 } ]; px = 1.2.0.0/18; -- cgit v1.2.3