From: Pablo Neira Ayuso Date: Thu, 13 Feb 2025 17:56:46 +0000 (+0100) Subject: src: add symbol range expression to further compact intervals X-Git-Tag: v1.1.2~83 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=347039f64509;p=thirdparty%2Fnftables.git src: add symbol range expression to further compact intervals Update parser to use a new symbol range expression with smaller memory footprint than range expression + two symbol expressions. The evaluation step translates this into EXPR_RANGE_VALUE for interval sets. Note that maps or concatenations still use the less compact range expressions representation, those require more work to use this new symbol range expression. The parser also uses the classic range expression if variables are used. Testing with a 100k intervals, worst case scenario: no prefix or singleton elements. This shows a reduction from 49.58 Mbytes to 35.47 Mbytes (-29.56% memory footprint for this case). This follow up work to previous commits: 91dc281a82ea ("src: rework singleton interval transformation to reduce memory consumption") c9ee9032b0ee ("src: add EXPR_RANGE_VALUE expression and use it") Signed-off-by: Pablo Neira Ayuso --- diff --git a/include/expression.h b/include/expression.h index f2b45250..84727486 100644 --- a/include/expression.h +++ b/include/expression.h @@ -49,6 +49,7 @@ * @EXPR_SET_ELEM_CATCHALL catchall element expression * @EXPR_FLAGCMP flagcmp expression * @EXPR_RANGE_VALUE constant range expression + * @EXPR_RANGE_SYMBOL unparse symbol range expression */ enum expr_types { EXPR_INVALID, @@ -82,6 +83,7 @@ enum expr_types { EXPR_SET_ELEM_CATCHALL, EXPR_FLAGCMP, EXPR_RANGE_VALUE, + EXPR_RANGE_SYMBOL, EXPR_MAX = EXPR_FLAGCMP }; @@ -261,9 +263,12 @@ struct expr { union { struct { - /* EXPR_SYMBOL */ + /* EXPR_SYMBOL, EXPR_RANGE_SYMBOL */ const struct scope *scope; - const char *identifier; + union { + const char *identifier; + const char *identifier_range[2]; + }; enum symbol_types symtype; }; struct { @@ -486,6 +491,10 @@ extern struct expr *constant_range_expr_alloc(const struct location *loc, unsigned int len, mpz_t low, mpz_t high); +struct expr *symbol_range_expr_alloc(const struct location *loc, + enum symbol_types type, const struct scope *scope, + const char *identifier_low, const char *identifier_high); + extern struct expr *flag_expr_alloc(const struct location *loc, const struct datatype *dtype, enum byteorder byteorder, diff --git a/src/evaluate.c b/src/evaluate.c index 69240188..3cf58d85 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -2319,6 +2319,51 @@ static int expr_evaluate_mapping(struct eval_ctx *ctx, struct expr **expr) return 0; } +static int expr_evaluate_symbol_range(struct eval_ctx *ctx, struct expr **exprp) +{ + struct expr *left, *right, *range; + struct expr *expr = *exprp; + + left = symbol_expr_alloc(&expr->location, expr->symtype, (struct scope *)expr->scope, expr->identifier_range[0]); + if (expr_evaluate_symbol(ctx, &left) < 0) { + expr_free(left); + return -1; + } + + right = symbol_expr_alloc(&expr->location, expr->symtype, (struct scope *)expr->scope, expr->identifier_range[1]); + if (expr_evaluate_symbol(ctx, &right) < 0) { + expr_free(left); + expr_free(right); + return -1; + } + + /* concatenation and maps need more work to use constant_range_expr. */ + if (ctx->set && !set_is_map(ctx->set->flags) && + set_is_non_concat_range(ctx->set) && + left->etype == EXPR_VALUE && + right->etype == EXPR_VALUE) { + range = constant_range_expr_alloc(&expr->location, left->dtype, + left->byteorder, + left->len, + left->value, + right->value); + expr_free(left); + expr_free(right); + expr_free(expr); + *exprp = range; + return 0; + } + + range = range_expr_alloc(&expr->location, left, right); + expr_free(expr); + *exprp = range; + + if (expr_evaluate(ctx, exprp) < 0) + return -1; + + return 0; +} + /* We got datatype context via statement. If the basetype is compatible, set * this expression datatype to the one of the statement to make it datatype * compatible. This is a more conservative approach than enabling datatype @@ -3027,6 +3072,8 @@ static int expr_evaluate(struct eval_ctx *ctx, struct expr **expr) return expr_evaluate_set_elem_catchall(ctx, expr); case EXPR_FLAGCMP: return expr_evaluate_flagcmp(ctx, expr); + case EXPR_RANGE_SYMBOL: + return expr_evaluate_symbol_range(ctx, expr); default: BUG("unknown expression type %s\n", expr_name(*expr)); } diff --git a/src/expression.c b/src/expression.c index b98b3d96..53d4c521 100644 --- a/src/expression.c +++ b/src/expression.c @@ -620,6 +620,50 @@ struct expr *constant_range_expr_alloc(const struct location *loc, return expr; } +static void symbol_range_expr_print(const struct expr *expr, struct output_ctx *octx) +{ + nft_print(octx, "%s", expr->identifier_range[0]); + nft_print(octx, "-"); + nft_print(octx, "%s", expr->identifier_range[1]); +} + +static void symbol_range_expr_clone(struct expr *new, const struct expr *expr) +{ + new->symtype = expr->symtype; + new->scope = expr->scope; + new->identifier_range[0] = xstrdup(expr->identifier_range[0]); + new->identifier_range[1] = xstrdup(expr->identifier_range[1]); +} + +static void symbol_range_expr_destroy(struct expr *expr) +{ + free_const(expr->identifier_range[0]); + free_const(expr->identifier_range[1]); +} + +static const struct expr_ops symbol_range_expr_ops = { + .type = EXPR_RANGE_SYMBOL, + .name = "range_symbol", + .print = symbol_range_expr_print, + .clone = symbol_range_expr_clone, + .destroy = symbol_range_expr_destroy, +}; + +struct expr *symbol_range_expr_alloc(const struct location *loc, + enum symbol_types type, const struct scope *scope, + const char *identifier_low, const char *identifier_high) +{ + struct expr *expr; + + expr = expr_alloc(loc, EXPR_RANGE_SYMBOL, &invalid_type, + BYTEORDER_INVALID, 0); + expr->symtype = type; + expr->scope = scope; + expr->identifier_range[0] = xstrdup(identifier_low); + expr->identifier_range[1] = xstrdup(identifier_high); + return expr; +} + /* * Allocate a constant expression with a single bit set at position n. */ @@ -1699,6 +1743,7 @@ static const struct expr_ops *__expr_ops_by_type(enum expr_types etype) case EXPR_SET_ELEM_CATCHALL: return &set_elem_catchall_expr_ops; case EXPR_FLAGCMP: return &flagcmp_expr_ops; case EXPR_RANGE_VALUE: return &constant_range_expr_ops; + case EXPR_RANGE_SYMBOL: return &symbol_range_expr_ops; } return NULL; diff --git a/src/optimize.c b/src/optimize.c index 03c8bad2..230fe4a2 100644 --- a/src/optimize.c +++ b/src/optimize.c @@ -139,6 +139,7 @@ static bool stmt_expr_supported(const struct expr *expr) { switch (expr->right->etype) { case EXPR_SYMBOL: + case EXPR_RANGE_SYMBOL: case EXPR_RANGE: case EXPR_PREFIX: case EXPR_SET: @@ -630,6 +631,7 @@ static void __merge_concat(const struct optimize_ctx *ctx, uint32_t i, case EXPR_SYMBOL: case EXPR_VALUE: case EXPR_PREFIX: + case EXPR_RANGE_SYMBOL: case EXPR_RANGE: clone = expr_clone(stmt_a->expr->right); compound_expr_add(concat, clone); @@ -730,6 +732,7 @@ static void build_verdict_map(struct expr *expr, struct stmt *verdict, stmt_free(counter); break; case EXPR_PREFIX: + case EXPR_RANGE_SYMBOL: case EXPR_RANGE: case EXPR_VALUE: case EXPR_SYMBOL: diff --git a/src/parser_bison.y b/src/parser_bison.y index fa8dc83f..f5512783 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -4425,7 +4425,16 @@ prefix_rhs_expr : basic_rhs_expr SLASH NUM range_rhs_expr : basic_rhs_expr DASH basic_rhs_expr { - $$ = range_expr_alloc(&@$, $1, $3); + if ($1->etype == EXPR_SYMBOL && + $1->symtype == SYMBOL_VALUE && + $3->etype == EXPR_SYMBOL && + $3->symtype == SYMBOL_VALUE) { + $$ = symbol_range_expr_alloc(&@$, $1->symtype, $1->scope, $1->identifier, $3->identifier); + expr_free($1); + expr_free($3); + } else { + $$ = range_expr_alloc(&@$, $1, $3); + } } ;