From cf8e0db8aacbafac5acb1f42afd62d8215ca5863 Mon Sep 17 00:00:00 2001 From: Shivani Bhardwaj Date: Sat, 23 Jan 2016 02:25:55 +0530 Subject: src: Add support for masquerade port selection Provide full support for masquerading by allowing port range selection, eg. # nft add rule nat postrouting ip protocol tcp masquerade to :1024-10024 Signed-off-by: Shivani Bhardwaj Signed-off-by: Pablo Neira Ayuso --- include/statement.h | 1 + src/evaluate.c | 6 ++++++ src/netlink_delinearize.c | 29 +++++++++++++++++++++++++++-- src/netlink_linearize.c | 24 ++++++++++++++++++++++++ src/parser_bison.y | 23 +++++++++++++++++------ src/statement.c | 11 +++++++++++ 6 files changed, 86 insertions(+), 8 deletions(-) diff --git a/include/statement.h b/include/statement.h index 102d95f1..e7872b0b 100644 --- a/include/statement.h +++ b/include/statement.h @@ -86,6 +86,7 @@ extern struct stmt *nat_stmt_alloc(const struct location *loc); struct masq_stmt { uint32_t flags; + struct expr *proto; }; extern struct stmt *masq_stmt_alloc(const struct location *loc); diff --git a/src/evaluate.c b/src/evaluate.c index 28e17cb2..b17cc82f 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1881,6 +1881,12 @@ static int stmt_evaluate_masq(struct eval_ctx *ctx, struct stmt *stmt) if (err < 0) return err; + if (stmt->masq.proto != NULL) { + err = nat_evaluate_transport(ctx, stmt, &stmt->masq.proto); + if (err < 0) + return err; + } + stmt->flags |= STMT_F_TERMINAL; return 0; } diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c index fae6e33d..d431588f 100644 --- a/src/netlink_delinearize.c +++ b/src/netlink_delinearize.c @@ -726,16 +726,41 @@ static void netlink_parse_masq(struct netlink_parse_ctx *ctx, const struct location *loc, const struct nftnl_expr *nle) { + enum nft_registers reg1, reg2; + struct expr *proto; struct stmt *stmt; - uint32_t flags; + uint32_t flags = 0; - flags = 0; if (nftnl_expr_is_set(nle, NFTNL_EXPR_MASQ_FLAGS)) flags = nftnl_expr_get_u32(nle, NFTNL_EXPR_MASQ_FLAGS); stmt = masq_stmt_alloc(loc); stmt->masq.flags = flags; + reg1 = netlink_parse_register(nle, NFTNL_EXPR_MASQ_REG_PROTO_MIN); + if (reg1) { + proto = netlink_get_register(ctx, loc, reg1); + if (proto == NULL) + return netlink_error(ctx, loc, + "MASQUERADE statement" + "has no proto expression"); + expr_set_type(proto, &inet_service_type, BYTEORDER_BIG_ENDIAN); + stmt->masq.proto = proto; + } + + reg2 = netlink_parse_register(nle, NFTNL_EXPR_MASQ_REG_PROTO_MAX); + if (reg2 && reg2 != reg1) { + proto = netlink_get_register(ctx, loc, reg2); + if (proto == NULL) + return netlink_error(ctx, loc, + "MASQUERADE statement" + "has no proto expression"); + expr_set_type(proto, &inet_service_type, BYTEORDER_BIG_ENDIAN); + if (stmt->masq.proto != NULL) + proto = range_expr_alloc(loc, stmt->masq.proto, proto); + stmt->masq.proto = proto; + } + list_add_tail(&stmt->list, &ctx->rule->stmts); } diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c index 7ff3b004..07f70e06 100644 --- a/src/netlink_linearize.c +++ b/src/netlink_linearize.c @@ -916,12 +916,36 @@ static void netlink_gen_nat_stmt(struct netlink_linearize_ctx *ctx, static void netlink_gen_masq_stmt(struct netlink_linearize_ctx *ctx, const struct stmt *stmt) { + enum nft_registers pmin_reg, pmax_reg; struct nftnl_expr *nle; + int registers = 0; nle = alloc_nft_expr("masq"); if (stmt->masq.flags != 0) nftnl_expr_set_u32(nle, NFTNL_EXPR_MASQ_FLAGS, stmt->masq.flags); + if (stmt->masq.proto) { + pmin_reg = get_register(ctx, NULL); + registers++; + + if (stmt->masq.proto->ops->type == EXPR_RANGE) { + pmax_reg = get_register(ctx, NULL); + registers++; + + netlink_gen_expr(ctx, stmt->masq.proto->left, pmin_reg); + netlink_gen_expr(ctx, stmt->masq.proto->right, pmax_reg); + netlink_put_register(nle, NFTNL_EXPR_MASQ_REG_PROTO_MIN, pmin_reg); + netlink_put_register(nle, NFTNL_EXPR_MASQ_REG_PROTO_MAX, pmax_reg); + } else { + netlink_gen_expr(ctx, stmt->masq.proto, pmin_reg); + netlink_put_register(nle, NFTNL_EXPR_MASQ_REG_PROTO_MIN, pmin_reg); + } + } + + while (registers > 0) { + release_register(ctx, NULL); + registers--; + } nftnl_rule_add_expr(ctx->nlr, nle); } diff --git a/src/parser_bison.y b/src/parser_bison.y index 05ade0fa..d41fc0ab 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -1644,17 +1644,28 @@ nat_stmt_args : stmt_expr } ; -masq_stmt : masq_stmt_alloc - | masq_stmt_alloc nf_nat_flags - { - $$ = $1; - $$->masq.flags = $2; - } +masq_stmt : masq_stmt_alloc masq_stmt_args + | masq_stmt_alloc ; masq_stmt_alloc : MASQUERADE { $$ = masq_stmt_alloc(&@$); } ; +masq_stmt_args : TO COLON stmt_expr + { + $0->masq.proto = $3; + } + | TO COLON stmt_expr nf_nat_flags + { + $0->masq.proto = $3; + $0->masq.flags = $4; + } + | nf_nat_flags + { + $0->masq.flags = $1; + } + ; + redir_stmt : redir_stmt_alloc redir_stmt_arg | redir_stmt_alloc ; diff --git a/src/statement.c b/src/statement.c index ca924410..2a6f19f8 100644 --- a/src/statement.c +++ b/src/statement.c @@ -385,13 +385,24 @@ static void masq_stmt_print(const struct stmt *stmt) { printf("masquerade"); + if (stmt->masq.proto) { + printf(" to :"); + expr_print(stmt->masq.proto); + } + print_nf_nat_flags(stmt->masq.flags); } +static void masq_stmt_destroy(struct stmt *stmt) +{ + expr_free(stmt->masq.proto); +} + static const struct stmt_ops masq_stmt_ops = { .type = STMT_MASQ, .name = "masq", .print = masq_stmt_print, + .destroy = masq_stmt_destroy, }; struct stmt *masq_stmt_alloc(const struct location *loc) -- cgit v1.2.3