From 7898b0fb2018ecec894e8bf6cf1c1102a7b4c9ee Mon Sep 17 00:00:00 2001 From: Laura Garcia Liebana Date: Tue, 13 Sep 2016 13:50:41 +0200 Subject: expr: numgen: add number generation offset Add support to pass through an offset value to the counter initialization. With this feature, the sysadmin is able to apply a value to be added to the generated number. Example: meta mark set numgen inc mod 2 offset 100 This will generate marks with series 100, 101, 100, 101, ... Suggested-by: Pablo Neira Ayuso Signed-off-by: Laura Garcia Liebana Signed-off-by: Pablo Neira Ayuso --- include/libnftnl/expr.h | 1 + include/linux/netfilter/nf_tables.h | 2 ++ src/expr/numgen.c | 39 +++++++++++++++++++++++++++++++------ tests/nft-expr_numgen-test.c | 4 ++++ 4 files changed, 40 insertions(+), 6 deletions(-) diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h index 8b35203..a8206ba 100644 --- a/include/libnftnl/expr.h +++ b/include/libnftnl/expr.h @@ -54,6 +54,7 @@ enum { NFTNL_EXPR_NG_DREG = NFTNL_EXPR_BASE, NFTNL_EXPR_NG_MODULUS, NFTNL_EXPR_NG_TYPE, + NFTNL_EXPR_NG_OFFSET, }; enum { diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h index e608054..038895b 100644 --- a/include/linux/netfilter/nf_tables.h +++ b/include/linux/netfilter/nf_tables.h @@ -1130,12 +1130,14 @@ enum nft_trace_types { * @NFTA_NG_DREG: destination register (NLA_U32) * @NFTA_NG_MODULUS: maximum value to be returned (NLA_U32) * @NFTA_NG_TYPE: operation type (NLA_U32) + * @NFTA_NG_OFFSET: offset to be added to the counter (NLA_U32) */ enum nft_ng_attributes { NFTA_NG_UNSPEC, NFTA_NG_DREG, NFTA_NG_MODULUS, NFTA_NG_TYPE, + NFTA_NG_OFFSET, __NFTA_NG_MAX }; #define NFTA_NG_MAX (__NFTA_NG_MAX - 1) diff --git a/src/expr/numgen.c b/src/expr/numgen.c index a23be53..8b667c2 100644 --- a/src/expr/numgen.c +++ b/src/expr/numgen.c @@ -24,6 +24,7 @@ struct nftnl_expr_ng { enum nft_registers dreg; unsigned int modulus; enum nft_ng_types type; + unsigned int offset; }; static int @@ -42,6 +43,9 @@ nftnl_expr_ng_set(struct nftnl_expr *e, uint16_t type, case NFTNL_EXPR_NG_TYPE: ng->type = *((uint32_t *)data); break; + case NFTNL_EXPR_NG_OFFSET: + ng->offset = *((uint32_t *)data); + break; default: return -1; } @@ -64,6 +68,9 @@ nftnl_expr_ng_get(const struct nftnl_expr *e, uint16_t type, case NFTNL_EXPR_NG_TYPE: *data_len = sizeof(ng->type); return &ng->type; + case NFTNL_EXPR_NG_OFFSET: + *data_len = sizeof(ng->offset); + return &ng->offset; } return NULL; } @@ -80,6 +87,7 @@ static int nftnl_expr_ng_cb(const struct nlattr *attr, void *data) case NFTA_NG_DREG: case NFTA_NG_MODULUS: case NFTA_NG_TYPE: + case NFTA_NG_OFFSET: if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) abi_breakage(); break; @@ -100,6 +108,8 @@ nftnl_expr_ng_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) mnl_attr_put_u32(nlh, NFTA_NG_MODULUS, htonl(ng->modulus)); if (e->flags & (1 << NFTNL_EXPR_NG_TYPE)) mnl_attr_put_u32(nlh, NFTA_NG_TYPE, htonl(ng->type)); + if (e->flags & (1 << NFTNL_EXPR_NG_OFFSET)) + mnl_attr_put_u32(nlh, NFTA_NG_OFFSET, htonl(ng->offset)); } static int @@ -124,6 +134,10 @@ nftnl_expr_ng_parse(struct nftnl_expr *e, struct nlattr *attr) ng->type = ntohl(mnl_attr_get_u32(tb[NFTA_NG_TYPE])); e->flags |= (1 << NFTNL_EXPR_NG_TYPE); } + if (tb[NFTA_NG_OFFSET]) { + ng->offset = ntohl(mnl_attr_get_u32(tb[NFTA_NG_OFFSET])); + e->flags |= (1 << NFTNL_EXPR_NG_OFFSET); + } return ret; } @@ -132,7 +146,7 @@ static int nftnl_expr_ng_json_parse(struct nftnl_expr *e, json_t *root, struct nftnl_parse_err *err) { #ifdef JSON_PARSING - uint32_t dreg, modulus, type; + uint32_t dreg, modulus, type, offset; if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32, &dreg, err) == 0) @@ -146,6 +160,10 @@ static int nftnl_expr_ng_json_parse(struct nftnl_expr *e, json_t *root, &type, err) == 0) nftnl_expr_set_u32(e, NFTNL_EXPR_NG_TYPE, type); + if (nftnl_jansson_parse_val(root, "offset", NFTNL_TYPE_U32, + &offset, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_OFFSET, offset); + return 0; #else errno = EOPNOTSUPP; @@ -159,7 +177,7 @@ static int nftnl_expr_ng_xml_parse(struct nftnl_expr *e, struct nftnl_parse_err *err) { #ifdef XML_PARSING - uint32_t dreg, modulus, type; + uint32_t dreg, modulus, type, offset; if (nftnl_mxml_reg_parse(tree, "dreg", &dreg, MXML_DESCEND_FIRST, NFTNL_XML_MAND, err) == 0) @@ -175,6 +193,11 @@ static int nftnl_expr_ng_xml_parse(struct nftnl_expr *e, err) == 0) nftnl_expr_set_u32(e, NFTNL_EXPR_NG_TYPE, type); + if (nftnl_mxml_num_parse(tree, "offset", MXML_DESCEND_FIRST, BASE_DEC, + &offset, NFTNL_TYPE_U32, NFTNL_XML_MAND, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_OFFSET, offset); + return 0; #else errno = EOPNOTSUPP; @@ -191,13 +214,13 @@ nftnl_expr_ng_snprintf_default(char *buf, size_t size, switch (ng->type) { case NFT_NG_INCREMENTAL: - ret = snprintf(buf, len, "reg %u = inc mod %u ", ng->dreg, - ng->modulus); + ret = snprintf(buf, len, "reg %u = %u + inc mod %u ", ng->dreg, + ng->offset, ng->modulus); SNPRINTF_BUFFER_SIZE(ret, size, len, offset); break; case NFT_NG_RANDOM: - ret = snprintf(buf, len, "reg %u = random mod %u ", ng->dreg, - ng->modulus); + ret = snprintf(buf, len, "reg %u = %u + random mod %u ", + ng->dreg, ng->offset, ng->modulus); SNPRINTF_BUFFER_SIZE(ret, size, len, offset); break; default: @@ -220,6 +243,8 @@ static int nftnl_expr_ng_export(char *buf, size_t size, nftnl_buf_u32(&b, type, ng->modulus, MODULUS); if (e->flags & (1 << NFTNL_EXPR_NG_TYPE)) nftnl_buf_u32(&b, type, ng->type, TYPE); + if (e->flags & (1 << NFTNL_EXPR_NG_OFFSET)) + nftnl_buf_u32(&b, type, ng->type, OFFSET); return nftnl_buf_done(&b); } @@ -253,6 +278,8 @@ static bool nftnl_expr_ng_cmp(const struct nftnl_expr *e1, eq &= (n1->modulus == n2->modulus); if (e1->flags & (1 << NFTNL_EXPR_NG_TYPE)) eq &= (n1->type == n2->type); + if (e1->flags & (1 << NFTNL_EXPR_NG_OFFSET)) + eq &= (n1->offset == n2->offset); return eq; } diff --git a/tests/nft-expr_numgen-test.c b/tests/nft-expr_numgen-test.c index 7092c8d..0d0a3bb 100644 --- a/tests/nft-expr_numgen-test.c +++ b/tests/nft-expr_numgen-test.c @@ -39,6 +39,9 @@ static void cmp_nftnl_expr(struct nftnl_expr *rule_a, if (nftnl_expr_get_u32(rule_a, NFTNL_EXPR_NG_TYPE) != nftnl_expr_get_u32(rule_b, NFTNL_EXPR_NG_TYPE)) print_err("Expr NFTNL_EXPR_NG_TYPE mismatches"); + if (nftnl_expr_get_u32(rule_a, NFTNL_EXPR_NG_OFFSET) != + nftnl_expr_get_u32(rule_b, NFTNL_EXPR_NG_OFFSET)) + print_err("Expr NFTNL_EXPR_NG_OFFSET mismatches"); } int main(int argc, char *argv[]) @@ -61,6 +64,7 @@ int main(int argc, char *argv[]) nftnl_expr_set_u32(ex, NFTNL_EXPR_NG_DREG, 0x1234568); nftnl_expr_set_u32(ex, NFTNL_EXPR_NG_MODULUS, 0x78123456); nftnl_expr_set_u32(ex, NFTNL_EXPR_NG_TYPE, NFT_NG_INCREMENTAL); + nftnl_expr_set_u32(ex, NFTNL_EXPR_NG_OFFSET, 0x1000000); nftnl_rule_add_expr(a, ex); -- cgit v1.2.3