From 200da4866ada06b2ee0f708c93dbdf9dcd0fcfe4 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 20 Sep 2016 17:53:21 +0200 Subject: src: add range expression Add range expression available that is scheduled for linux kernel 4.9. This range expression allows us to check if a given value placed in a register is within/outside a specified interval. Signed-off-by: Pablo Neira Ayuso --- include/libnftnl/expr.h | 7 + include/linux/netfilter/nf_tables.h | 29 ++++ src/Makefile.am | 1 + src/expr/range.c | 288 ++++++++++++++++++++++++++++++++++++ src/expr_ops.c | 2 + tests/Makefile.am | 4 + tests/nft-expr_range-test.c | 109 ++++++++++++++ tests/test-script.sh | 1 + 8 files changed, 441 insertions(+) create mode 100644 src/expr/range.c create mode 100644 tests/nft-expr_range-test.c diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h index 4ce2592..edf86a9 100644 --- a/include/libnftnl/expr.h +++ b/include/libnftnl/expr.h @@ -69,6 +69,13 @@ enum { NFTNL_EXPR_CMP_DATA, }; +enum { + NFTNL_EXPR_RANGE_SREG = NFTNL_EXPR_BASE, + NFTNL_EXPR_RANGE_OP, + NFTNL_EXPR_RANGE_FROM_DATA, + NFTNL_EXPR_RANGE_TO_DATA, +}; + enum { NFTNL_EXPR_IMM_DREG = NFTNL_EXPR_BASE, NFTNL_EXPR_IMM_DATA, diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h index 681082e..30e3b21 100644 --- a/include/linux/netfilter/nf_tables.h +++ b/include/linux/netfilter/nf_tables.h @@ -546,6 +546,35 @@ enum nft_cmp_attributes { }; #define NFTA_CMP_MAX (__NFTA_CMP_MAX - 1) +/** + * enum nft_range_ops - nf_tables range operator + * + * @NFT_RANGE_EQ: equal + * @NFT_RANGE_NEQ: not equal + */ +enum nft_range_ops { + NFT_RANGE_EQ, + NFT_RANGE_NEQ, +}; + +/** + * enum nft_range_attributes - nf_tables range expression netlink attributes + * + * @NFTA_RANGE_SREG: source register of data to compare (NLA_U32: nft_registers) + * @NFTA_RANGE_OP: cmp operation (NLA_U32: nft_cmp_ops) + * @NFTA_RANGE_FROM_DATA: data range from (NLA_NESTED: nft_data_attributes) + * @NFTA_RANGE_TO_DATA: data range to (NLA_NESTED: nft_data_attributes) + */ +enum nft_range_attributes { + NFTA_RANGE_UNSPEC, + NFTA_RANGE_SREG, + NFTA_RANGE_OP, + NFTA_RANGE_FROM_DATA, + NFTA_RANGE_TO_DATA, + __NFTA_RANGE_MAX +}; +#define NFTA_RANGE_MAX (__NFTA_RANGE_MAX - 1) + enum nft_lookup_flags { NFT_LOOKUP_F_INV = (1 << 0), }; diff --git a/src/Makefile.am b/src/Makefile.am index 4ab8fca..eac7a56 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -24,6 +24,7 @@ libnftnl_la_SOURCES = utils.c \ expr/bitwise.c \ expr/byteorder.c \ expr/cmp.c \ + expr/range.c \ expr/counter.c \ expr/ct.c \ expr/data_reg.c \ diff --git a/src/expr/range.c b/src/expr/range.c new file mode 100644 index 0000000..1489d58 --- /dev/null +++ b/src/expr/range.c @@ -0,0 +1,288 @@ +/* + * (C) 2016 by Pablo Neira Ayuso + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include "internal.h" + +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +struct nftnl_expr_range { + union nftnl_data_reg data_from; + union nftnl_data_reg data_to; + enum nft_registers sreg; + enum nft_range_ops op; +}; + +static int nftnl_expr_range_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_RANGE_SREG: + range->sreg = *((uint32_t *)data); + break; + case NFTNL_EXPR_RANGE_OP: + range->op = *((uint32_t *)data); + break; + case NFTNL_EXPR_RANGE_FROM_DATA: + memcpy(&range->data_from.val, data, data_len); + range->data_from.len = data_len; + break; + case NFTNL_EXPR_RANGE_TO_DATA: + memcpy(&range->data_to.val, data, data_len); + range->data_to.len = data_len; + break; + default: + return -1; + } + return 0; +} + +static const void *nftnl_expr_range_get(const struct nftnl_expr *e, + uint16_t type, uint32_t *data_len) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_RANGE_SREG: + *data_len = sizeof(range->sreg); + return &range->sreg; + case NFTNL_EXPR_RANGE_OP: + *data_len = sizeof(range->op); + return &range->op; + case NFTNL_EXPR_RANGE_FROM_DATA: + *data_len = range->data_from.len; + return &range->data_from.val; + case NFTNL_EXPR_RANGE_TO_DATA: + *data_len = range->data_to.len; + return &range->data_to.val; + } + return NULL; +} + +static int nftnl_expr_range_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFTA_RANGE_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_RANGE_SREG: + case NFTA_RANGE_OP: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_RANGE_FROM_DATA: + case NFTA_RANGE_TO_DATA: + if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_range_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_RANGE_SREG)) + mnl_attr_put_u32(nlh, NFTA_RANGE_SREG, htonl(range->sreg)); + if (e->flags & (1 << NFTNL_EXPR_RANGE_OP)) + mnl_attr_put_u32(nlh, NFTA_RANGE_OP, htonl(range->op)); + if (e->flags & (1 << NFTNL_EXPR_RANGE_FROM_DATA)) { + struct nlattr *nest; + + nest = mnl_attr_nest_start(nlh, NFTA_RANGE_FROM_DATA); + mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_from.len, + range->data_from.val); + mnl_attr_nest_end(nlh, nest); + } + if (e->flags & (1 << NFTNL_EXPR_RANGE_TO_DATA)) { + struct nlattr *nest; + + nest = mnl_attr_nest_start(nlh, NFTA_RANGE_TO_DATA); + mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_to.len, + range->data_to.val); + mnl_attr_nest_end(nlh, nest); + } +} + +static int +nftnl_expr_range_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + struct nlattr *tb[NFTA_RANGE_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_range_cb, tb) < 0) + return -1; + + if (tb[NFTA_RANGE_SREG]) { + range->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_SREG])); + e->flags |= (1 << NFTA_RANGE_SREG); + } + if (tb[NFTA_RANGE_OP]) { + range->op = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_OP])); + e->flags |= (1 << NFTA_RANGE_OP); + } + if (tb[NFTA_RANGE_FROM_DATA]) { + ret = nftnl_parse_data(&range->data_from, + tb[NFTA_RANGE_FROM_DATA], NULL); + e->flags |= (1 << NFTA_RANGE_FROM_DATA); + } + if (tb[NFTA_RANGE_TO_DATA]) { + ret = nftnl_parse_data(&range->data_to, + tb[NFTA_RANGE_TO_DATA], NULL); + e->flags |= (1 << NFTA_RANGE_TO_DATA); + } + + return ret; +} + +static char *expr_range_str[] = { + [NFT_RANGE_EQ] = "eq", + [NFT_RANGE_NEQ] = "neq", +}; + +static const char *range2str(uint32_t op) +{ + if (op > NFT_RANGE_NEQ) + return "unknown"; + + return expr_range_str[op]; +} + +static inline int nftnl_str2range(const char *op) +{ + if (strcmp(op, "eq") == 0) + return NFT_RANGE_EQ; + else if (strcmp(op, "neq") == 0) + return NFT_RANGE_NEQ; + else { + errno = EINVAL; + return -1; + } +} + +static int nftnl_expr_range_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + struct nftnl_expr_range *range = nftnl_expr_data(e); + const char *op; + uint32_t uval32; + int base; + + if (nftnl_jansson_parse_val(root, "sreg", NFTNL_TYPE_U32, &uval32, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_RANGE_SREG, uval32); + + op = nftnl_jansson_parse_str(root, "op", err); + if (op != NULL) { + base = nftnl_str2range(op); + if (base < 0) + return -1; + + nftnl_expr_set_u32(e, NFTNL_EXPR_RANGE_OP, base); + } + + if (nftnl_jansson_data_reg_parse(root, "data_from", + &range->data_from, err) == DATA_VALUE) + e->flags |= (1 << NFTNL_EXPR_RANGE_FROM_DATA); + + if (nftnl_jansson_data_reg_parse(root, "data_to", + &range->data_to, err) == DATA_VALUE) + e->flags |= (1 << NFTNL_EXPR_RANGE_TO_DATA); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int nftnl_expr_range_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_RANGE_SREG)) + nftnl_buf_u32(&b, type, range->sreg, SREG); + if (e->flags & (1 << NFTNL_EXPR_RANGE_OP)) + nftnl_buf_str(&b, type, range2str(range->op), OP); + if (e->flags & (1 << NFTNL_EXPR_RANGE_FROM_DATA)) + nftnl_buf_reg(&b, type, &range->data_from, DATA_VALUE, DATA); + if (e->flags & (1 << NFTNL_EXPR_RANGE_TO_DATA)) + nftnl_buf_reg(&b, type, &range->data_to, DATA_VALUE, DATA); + + return nftnl_buf_done(&b); +} + +static int nftnl_expr_range_snprintf_default(char *buf, size_t size, + const struct nftnl_expr *e) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + int len = size, offset = 0, ret; + + ret = snprintf(buf, len, "%s reg %u ", + expr_range_str[range->op], range->sreg); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + ret = nftnl_data_reg_snprintf(buf + offset, len, &range->data_from, + NFTNL_OUTPUT_DEFAULT, 0, DATA_VALUE); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + ret = nftnl_data_reg_snprintf(buf + offset, len, &range->data_to, + NFTNL_OUTPUT_DEFAULT, 0, DATA_VALUE); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + return offset; +} + +static int nftnl_expr_range_snprintf(char *buf, size_t size, uint32_t type, + uint32_t flags, const struct nftnl_expr *e) +{ + switch (type) { + case NFTNL_OUTPUT_DEFAULT: + return nftnl_expr_range_snprintf_default(buf, size, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_range_export(buf, size, e, type); + default: + break; + } + return -1; +} + +struct expr_ops expr_ops_range = { + .name = "range", + .alloc_len = sizeof(struct nftnl_expr_range), + .max_attr = NFTA_RANGE_MAX, + .set = nftnl_expr_range_set, + .get = nftnl_expr_range_get, + .parse = nftnl_expr_range_parse, + .build = nftnl_expr_range_build, + .snprintf = nftnl_expr_range_snprintf, + .json_parse = nftnl_expr_range_json_parse, +}; diff --git a/src/expr_ops.c b/src/expr_ops.c index 2a047d2..55748d6 100644 --- a/src/expr_ops.c +++ b/src/expr_ops.c @@ -22,6 +22,7 @@ extern struct expr_ops expr_ops_meta; extern struct expr_ops expr_ops_ng; extern struct expr_ops expr_ops_nat; extern struct expr_ops expr_ops_payload; +extern struct expr_ops expr_ops_range; extern struct expr_ops expr_ops_redir; extern struct expr_ops expr_ops_reject; extern struct expr_ops expr_ops_queue; @@ -49,6 +50,7 @@ static struct expr_ops *expr_ops[] = { &expr_ops_ng, &expr_ops_nat, &expr_ops_payload, + &expr_ops_range, &expr_ops_redir, &expr_ops_reject, &expr_ops_queue, diff --git a/tests/Makefile.am b/tests/Makefile.am index 99d2974..d518959 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -27,6 +27,7 @@ check_PROGRAMS = nft-parsing-test \ nft-expr_nat-test \ nft-expr_payload-test \ nft-expr_queue-test \ + nft-expr_range-test \ nft-expr_quota-test \ nft-expr_redir-test \ nft-expr_reject-test \ @@ -108,6 +109,9 @@ nft_expr_queue_test_LDADD = ../src/libnftnl.la ${LIBMNL_LIBS} nft_expr_quota_test_SOURCES = nft-expr_quota-test.c nft_expr_quota_test_LDADD = ../src/libnftnl.la ${LIBMNL_LIBS} +nft_expr_range_test_SOURCES = nft-expr_range-test.c +nft_expr_range_test_LDADD = ../src/libnftnl.la ${LIBMNL_LIBS} + nft_expr_reject_test_SOURCES = nft-expr_reject-test.c nft_expr_reject_test_LDADD = ../src/libnftnl.la ${LIBMNL_LIBS} diff --git a/tests/nft-expr_range-test.c b/tests/nft-expr_range-test.c new file mode 100644 index 0000000..b92dfc0 --- /dev/null +++ b/tests/nft-expr_range-test.c @@ -0,0 +1,109 @@ +/* + * (C) 2013 by Ana Rey Botello + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static int test_ok = 1; + +static void print_err(const char *msg) +{ + test_ok = 0; + printf("\033[31mERROR:\e[0m %s\n", msg); +} + +static void range_nftnl_expr(struct nftnl_expr *rule_a, + struct nftnl_expr *rule_b) +{ + uint32_t data_a, data_b; + + nftnl_expr_get(rule_a, NFTNL_EXPR_RANGE_FROM_DATA, &data_a); + nftnl_expr_get(rule_b, NFTNL_EXPR_RANGE_FROM_DATA, &data_b); + if (data_a != data_b) + print_err("Size of NFTNL_EXPR_RANGE_FROM_DATA mismatches"); + nftnl_expr_get(rule_a, NFTNL_EXPR_RANGE_TO_DATA, &data_a); + nftnl_expr_get(rule_b, NFTNL_EXPR_RANGE_TO_DATA, &data_b); + if (data_a != data_b) + print_err("Size of NFTNL_EXPR_RANGE_TO_DATA mismatches"); + if (nftnl_expr_get_u32(rule_a, NFTNL_EXPR_RANGE_SREG) != + nftnl_expr_get_u32(rule_b, NFTNL_EXPR_RANGE_SREG)) + print_err("Expr NFTNL_EXPR_RANGE_SREG mismatches"); + if (nftnl_expr_get_u32(rule_a, NFTNL_EXPR_RANGE_OP) != + nftnl_expr_get_u32(rule_b, NFTNL_EXPR_RANGE_OP)) + print_err("Expr NFTNL_EXPR_RANGE_OP mismatches"); +} + +int main(int argc, char *argv[]) +{ + struct nftnl_rule *a, *b; + struct nftnl_expr *ex; + struct nlmsghdr *nlh; + char buf[4096]; + struct nftnl_expr_iter *iter_a, *iter_b; + struct nftnl_expr *rule_a, *rule_b; + uint32_t data_a = 0x01010101, data_b = 0x02020202; + + a = nftnl_rule_alloc(); + b = nftnl_rule_alloc(); + if (a == NULL || b == NULL) + print_err("OOM"); + ex = nftnl_expr_alloc("range"); + if (ex == NULL) + print_err("OOM"); + + nftnl_expr_set(ex, NFTNL_EXPR_RANGE_FROM_DATA, + &data_a, sizeof(data_a)); + nftnl_expr_set(ex, NFTNL_EXPR_RANGE_TO_DATA, + &data_b, sizeof(data_b)); + nftnl_expr_set_u32(ex, NFTNL_EXPR_RANGE_SREG, 0x12345678); + nftnl_expr_set_u32(ex, NFTNL_EXPR_RANGE_OP, 0x78123456); + + nftnl_rule_add_expr(a, ex); + + nlh = nftnl_rule_nlmsg_build_hdr(buf, NFT_MSG_NEWRULE, AF_INET, 0, 1234); + nftnl_rule_nlmsg_build_payload(nlh, a); + + if (nftnl_rule_nlmsg_parse(nlh, b) < 0) + print_err("parsing problems"); + + iter_a = nftnl_expr_iter_create(a); + iter_b = nftnl_expr_iter_create(b); + if (iter_a == NULL || iter_b == NULL) + print_err("OOM"); + rule_a = nftnl_expr_iter_next(iter_a); + rule_b = nftnl_expr_iter_next(iter_b); + if (rule_a == NULL || rule_b == NULL) + print_err("OOM"); + + range_nftnl_expr(rule_a, rule_b); + + if (nftnl_expr_iter_next(iter_a) != NULL || + nftnl_expr_iter_next(iter_b) != NULL) + print_err("More 1 expr."); + + nftnl_expr_iter_destroy(iter_a); + nftnl_expr_iter_destroy(iter_b); + nftnl_rule_free(a); + nftnl_rule_free(b); + + if (!test_ok) + exit(EXIT_FAILURE); + + printf("%s: \033[32mOK\e[0m\n", argv[0]); + return EXIT_SUCCESS; +} diff --git a/tests/test-script.sh b/tests/test-script.sh index 1c93e93..3244f80 100755 --- a/tests/test-script.sh +++ b/tests/test-script.sh @@ -16,6 +16,7 @@ ./nft-expr_meta-test ./nft-expr_numgen-test ./nft-expr_queue-test +./nft-expr_range-test ./nft-expr_redir-test ./nft-expr_nat-test ./nft-expr_payload-test -- cgit v1.2.3