From 3a86406729782ee2671ec7161c76529c2e4a44e4 Mon Sep 17 00:00:00 2001 From: Laura Garcia Liebana Date: Tue, 28 Feb 2017 18:42:50 +0100 Subject: src: hash: support of symmetric hash This patch provides symmetric hash support according to source ip address and port, and destination ip address and port. The new attribute NFTA_HASH_TYPE has been included to support different types of hashing functions. Currently supported NFT_HASH_JENKINS through jhash and NFT_HASH_SYM through symhash. The main difference between both types are: - jhash requires an expression with sreg, symhash doesn't. - symhash supports modulus and offset, but not seed. Examples: nft add rule ip nat prerouting ct mark set jhash ip saddr mod 2 nft add rule ip nat prerouting ct mark set symhash mod 2 Signed-off-by: Laura Garcia Liebana Signed-off-by: Pablo Neira Ayuso --- include/expression.h | 1 + include/hash.h | 2 +- include/linux/netfilter/nf_tables.h | 13 +++++++++++++ src/evaluate.c | 3 ++- src/hash.c | 28 +++++++++++++++++++++------- src/netlink_delinearize.c | 35 +++++++++++++++++++++-------------- src/netlink_linearize.c | 19 ++++++++++++------- src/parser_bison.y | 16 ++++++++++------ src/scanner.l | 1 + tests/py/ip/hash.t | 1 + tests/py/ip/hash.t.payload | 4 ++++ 11 files changed, 87 insertions(+), 36 deletions(-) diff --git a/include/expression.h b/include/expression.h index 83ecf111..4f2948cc 100644 --- a/include/expression.h +++ b/include/expression.h @@ -309,6 +309,7 @@ struct expr { uint32_t mod; uint32_t seed; uint32_t offset; + enum nft_hash_types type; } hash; struct { /* EXPR_FIB */ diff --git a/include/hash.h b/include/hash.h index 8bf53e2e..7f9c6f13 100644 --- a/include/hash.h +++ b/include/hash.h @@ -3,6 +3,6 @@ extern struct expr *hash_expr_alloc(const struct location *loc, uint32_t modulus, uint32_t seed, - uint32_t offset); + uint32_t offset, enum nft_hash_types type); #endif /* NFTABLES_HASH_H */ diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h index 05215d30..4f7d7568 100644 --- a/include/linux/netfilter/nf_tables.h +++ b/include/linux/netfilter/nf_tables.h @@ -815,6 +815,17 @@ enum nft_rt_keys { NFT_RT_NEXTHOP6, }; +/** + * enum nft_hash_types - nf_tables hash expression types + * + * @NFT_HASH_JENKINS: Jenkins Hash + * @NFT_HASH_SYM: Symmetric Hash + */ +enum nft_hash_types { + NFT_HASH_JENKINS, + NFT_HASH_SYM, +}; + /** * enum nft_hash_attributes - nf_tables hash expression netlink attributes * @@ -824,6 +835,7 @@ enum nft_rt_keys { * @NFTA_HASH_MODULUS: modulus value (NLA_U32) * @NFTA_HASH_SEED: seed value (NLA_U32) * @NFTA_HASH_OFFSET: add this offset value to hash result (NLA_U32) + * @NFTA_HASH_TYPE: hash operation (NLA_U32: nft_hash_types) */ enum nft_hash_attributes { NFTA_HASH_UNSPEC, @@ -833,6 +845,7 @@ enum nft_hash_attributes { NFTA_HASH_MODULUS, NFTA_HASH_SEED, NFTA_HASH_OFFSET, + NFTA_HASH_TYPE, __NFTA_HASH_MAX, }; #define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1) diff --git a/src/evaluate.c b/src/evaluate.c index 54985166..efcafc72 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1288,7 +1288,8 @@ static int expr_evaluate_hash(struct eval_ctx *ctx, struct expr **exprp) expr_dtype_integer_compatible(ctx, expr); expr_set_context(&ctx->ectx, NULL, 0); - if (expr_evaluate(ctx, &expr->hash.expr) < 0) + if (expr->hash.expr && + expr_evaluate(ctx, &expr->hash.expr) < 0) return -1; /* expr_evaluate_primary() sets the context to what to the input diff --git a/src/hash.c b/src/hash.c index d26b2eda..a7a96122 100644 --- a/src/hash.c +++ b/src/hash.c @@ -17,10 +17,18 @@ static void hash_expr_print(const struct expr *expr) { - printf("jhash "); - expr_print(expr->hash.expr); + switch (expr->hash.type) { + case NFT_HASH_SYM: + printf("symhash"); + break; + case NFT_HASH_JENKINS: + default: + printf("jhash "); + expr_print(expr->hash.expr); + } + printf(" mod %u", expr->hash.mod); - if (expr->hash.seed) + if (expr->hash.type & NFT_HASH_JENKINS && expr->hash.seed) printf(" seed 0x%x", expr->hash.seed); if (expr->hash.offset) printf(" offset %u", expr->hash.offset); @@ -28,18 +36,22 @@ static void hash_expr_print(const struct expr *expr) static bool hash_expr_cmp(const struct expr *e1, const struct expr *e2) { - return expr_cmp(e1->hash.expr, e2->hash.expr) && + return (e1->hash.expr || + expr_cmp(e1->hash.expr, e2->hash.expr)) && e1->hash.mod == e2->hash.mod && e1->hash.seed == e2->hash.seed && - e1->hash.offset == e2->hash.offset; + e1->hash.offset == e2->hash.offset && + e1->hash.type == e2->hash.type; } static void hash_expr_clone(struct expr *new, const struct expr *expr) { - new->hash.expr = expr_clone(expr->hash.expr); + if (expr->hash.expr) + new->hash.expr = expr_clone(expr->hash.expr); new->hash.mod = expr->hash.mod; new->hash.seed = expr->hash.seed; new->hash.offset = expr->hash.offset; + new->hash.type = expr->hash.type; } static const struct expr_ops hash_expr_ops = { @@ -51,7 +63,8 @@ static const struct expr_ops hash_expr_ops = { }; struct expr *hash_expr_alloc(const struct location *loc, uint32_t mod, - uint32_t seed, uint32_t offset) + uint32_t seed, uint32_t offset, + enum nft_hash_types type) { struct expr *expr; @@ -60,6 +73,7 @@ struct expr *hash_expr_alloc(const struct location *loc, uint32_t mod, expr->hash.mod = mod; expr->hash.seed = seed; expr->hash.offset = offset; + expr->hash.type = type; return expr; } diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c index 39347e01..36e8fe3c 100644 --- a/src/netlink_delinearize.c +++ b/src/netlink_delinearize.c @@ -523,27 +523,33 @@ static void netlink_parse_hash(struct netlink_parse_ctx *ctx, enum nft_registers sreg, dreg; struct expr *expr, *hexpr; uint32_t mod, seed, len, offset; + enum nft_hash_types type; - sreg = netlink_parse_register(nle, NFTNL_EXPR_HASH_SREG); - hexpr = netlink_get_register(ctx, loc, sreg); - if (hexpr == NULL) - return netlink_error(ctx, loc, - "hash statement has no expression"); - + type = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_TYPE); offset = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_OFFSET); seed = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_SEED); mod = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_MODULUS); - len = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_LEN) * BITS_PER_BYTE; - if (hexpr->len < len) { - hexpr = netlink_parse_concat_expr(ctx, loc, sreg, len); + expr = hash_expr_alloc(loc, mod, seed, offset, type); + + if (type != NFT_HASH_SYM) { + sreg = netlink_parse_register(nle, NFTNL_EXPR_HASH_SREG); + hexpr = netlink_get_register(ctx, loc, sreg); + if (hexpr == NULL) - return; + return + netlink_error(ctx, loc, + "hash statement has no expression"); + len = nftnl_expr_get_u32(nle, + NFTNL_EXPR_HASH_LEN) * BITS_PER_BYTE; + if (hexpr->len < len) { + hexpr = netlink_parse_concat_expr(ctx, loc, sreg, len); + if (hexpr == NULL) + return; + } + expr->hash.expr = hexpr; } - expr = hash_expr_alloc(loc, mod, seed, offset); - expr->hash.expr = hexpr; - dreg = netlink_parse_register(nle, NFTNL_EXPR_HASH_DREG); netlink_set_register(ctx, dreg, expr); } @@ -1826,7 +1832,8 @@ static void expr_postprocess(struct rule_pp_ctx *ctx, struct expr **exprp) case EXPR_FIB: break; case EXPR_HASH: - expr_postprocess(ctx, &expr->hash.expr); + if (expr->hash.expr) + expr_postprocess(ctx, &expr->hash.expr); break; case EXPR_CT: ct_expr_update_type(&ctx->pctx, expr); diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c index 48f34c25..293150e2 100644 --- a/src/netlink_linearize.c +++ b/src/netlink_linearize.c @@ -125,18 +125,23 @@ static void netlink_gen_hash(struct netlink_linearize_ctx *ctx, enum nft_registers sreg; struct nftnl_expr *nle; - sreg = get_register(ctx, expr->hash.expr); - netlink_gen_expr(ctx, expr->hash.expr, sreg); - release_register(ctx, expr->hash.expr); - nle = alloc_nft_expr("hash"); - netlink_put_register(nle, NFTNL_EXPR_HASH_SREG, sreg); + + if (expr->hash.expr) { + sreg = get_register(ctx, expr->hash.expr); + netlink_gen_expr(ctx, expr->hash.expr, sreg); + release_register(ctx, expr->hash.expr); + netlink_put_register(nle, NFTNL_EXPR_HASH_SREG, sreg); + + nftnl_expr_set_u32(nle, NFTNL_EXPR_HASH_LEN, + div_round_up(expr->hash.expr->len, + BITS_PER_BYTE)); + } netlink_put_register(nle, NFTNL_EXPR_HASH_DREG, dreg); - nftnl_expr_set_u32(nle, NFTNL_EXPR_HASH_LEN, - div_round_up(expr->hash.expr->len, BITS_PER_BYTE)); nftnl_expr_set_u32(nle, NFTNL_EXPR_HASH_MODULUS, expr->hash.mod); nftnl_expr_set_u32(nle, NFTNL_EXPR_HASH_SEED, expr->hash.seed); nftnl_expr_set_u32(nle, NFTNL_EXPR_HASH_OFFSET, expr->hash.offset); + nftnl_expr_set_u32(nle, NFTNL_EXPR_HASH_TYPE, expr->hash.type); nftnl_rule_add_expr(ctx->nlr, nle); } diff --git a/src/parser_bison.y b/src/parser_bison.y index 15931e96..dff8a5ab 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -437,6 +437,7 @@ static void location_update(struct location *loc, struct location *rhs, int n) %token OFFSET "offset" %token JHASH "jhash" +%token SYMHASH "symhash" %token SEED "seed" %token POSITION "position" @@ -512,7 +513,7 @@ static void location_update(struct location *loc, struct location *rhs, int n) %destructor { stmt_free($$); } reject_stmt reject_stmt_alloc %type nat_stmt nat_stmt_alloc masq_stmt masq_stmt_alloc redir_stmt redir_stmt_alloc %destructor { stmt_free($$); } nat_stmt nat_stmt_alloc masq_stmt masq_stmt_alloc redir_stmt redir_stmt_alloc -%type nf_nat_flags nf_nat_flag offset_opt +%type nf_nat_flags nf_nat_flag offset_opt seed_opt %type queue_stmt queue_stmt_alloc %destructor { stmt_free($$); } queue_stmt queue_stmt_alloc %type queue_stmt_flags queue_stmt_flag @@ -2916,15 +2917,18 @@ numgen_expr : NUMGEN numgen_type MOD NUM offset_opt } ; -hash_expr : JHASH expr MOD NUM SEED NUM offset_opt +seed_opt : /* empty */ { $$ = 0; } + | SEED NUM { $$ = $2; } + ; + +hash_expr : JHASH expr MOD NUM seed_opt offset_opt { - $$ = hash_expr_alloc(&@$, $4, $6, $7); + $$ = hash_expr_alloc(&@$, $4, $5, $6, NFT_HASH_JENKINS); $$->hash.expr = $2; } - | JHASH expr MOD NUM offset_opt + | SYMHASH MOD NUM offset_opt { - $$ = hash_expr_alloc(&@$, $4, 0, $5); - $$->hash.expr = $2; + $$ = hash_expr_alloc(&@$, $3, 0, $4, NFT_HASH_SYM); } ; diff --git a/src/scanner.l b/src/scanner.l index b70e1a80..003f15eb 100644 --- a/src/scanner.l +++ b/src/scanner.l @@ -488,6 +488,7 @@ addrstring ({macaddr}|{ip4addr}|{ip6addr}) "offset" { return OFFSET; } "jhash" { return JHASH; } +"symhash" { return SYMHASH; } "seed" { return SEED; } "dup" { return DUP; } diff --git a/tests/py/ip/hash.t b/tests/py/ip/hash.t index 0d01a11d..2becef62 100644 --- a/tests/py/ip/hash.t +++ b/tests/py/ip/hash.t @@ -6,3 +6,4 @@ ct mark set jhash ip saddr . ip daddr mod 2;ok ct mark set jhash ip saddr . ip daddr mod 2 seed 0xdeadbeef offset 100;ok ct mark set jhash ip saddr . ip daddr mod 2 offset 100;ok dnat to jhash ip saddr mod 2 seed 0xdeadbeef map { 0 : 192.168.20.100, 1 : 192.168.30.100 };ok +ct mark set symhash mod 2 offset 100;ok diff --git a/tests/py/ip/hash.t.payload b/tests/py/ip/hash.t.payload index 8c28ad98..21227e91 100644 --- a/tests/py/ip/hash.t.payload +++ b/tests/py/ip/hash.t.payload @@ -36,3 +36,7 @@ ip test-ip4 pre [ lookup reg 1 set __map%d dreg 1 ] [ nat dnat ip addr_min reg 1 addr_max reg 0 ] +# ct mark set symhash mod 2 offset 100 +ip test-ip4 pre + [ hash reg 1 = symhash() % mod 2 offset 100 ] + [ ct set mark with reg 1 ] -- cgit v1.2.3