From b4edb4fc558ac177b66a867fa058c7624840d895 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 27 Nov 2016 23:27:00 +0100 Subject: expr: add stateful object reference expression This patch adds a new "objref" expression that you can use to refer to stateful objects from rules. Signed-off-by: Pablo Neira Ayuso --- src/Makefile.am | 1 + src/expr/objref.c | 215 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ src/expr_ops.c | 2 + src/object.c | 5 ++ 4 files changed, 223 insertions(+) create mode 100644 src/expr/objref.c (limited to 'src') diff --git a/src/Makefile.am b/src/Makefile.am index 909c6a6..485a8c4 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -42,6 +42,7 @@ libnftnl_la_SOURCES = utils.c \ expr/meta.c \ expr/numgen.c \ expr/nat.c \ + expr/objref.c \ expr/payload.c \ expr/queue.c \ expr/quota.c \ diff --git a/src/expr/objref.c b/src/expr/objref.c new file mode 100644 index 0000000..01bea7b --- /dev/null +++ b/src/expr/objref.c @@ -0,0 +1,215 @@ +/* + * (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 +#include +#include +#include +#include + +#include + +#include "internal.h" +#include +#include +#include + +struct nftnl_expr_objref { + struct { + uint32_t type; + const char *name; + } imm; +}; + +static int nftnl_expr_objref_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_objref *objref = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_OBJREF_IMM_TYPE: + objref->imm.type = *((uint32_t *)data); + break; + case NFTNL_EXPR_OBJREF_IMM_NAME: + objref->imm.name = strdup(data); + if (!objref->imm.name) + return -1; + break; + default: + return -1; + } + return 0; +} + +static const void *nftnl_expr_objref_get(const struct nftnl_expr *e, + uint16_t type, uint32_t *data_len) +{ + struct nftnl_expr_objref *objref = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_OBJREF_IMM_TYPE: + *data_len = sizeof(objref->imm.type); + return &objref->imm.type; + case NFTNL_EXPR_OBJREF_IMM_NAME: + *data_len = strlen(objref->imm.name) + 1; + return objref->imm.name; + } + return NULL; +} + +static int nftnl_expr_objref_cb(const struct nlattr *attr, void *data) +{ + int type = mnl_attr_get_type(attr); + const struct nlattr **tb = data; + + if (mnl_attr_type_valid(attr, NFTA_OBJREF_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_OBJREF_IMM_TYPE: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_OBJREF_IMM_NAME: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void nftnl_expr_objref_build(struct nlmsghdr *nlh, + const struct nftnl_expr *e) +{ + struct nftnl_expr_objref *objref = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_OBJREF_IMM_TYPE)) + mnl_attr_put_u32(nlh, NFTA_OBJREF_IMM_TYPE, + htonl(objref->imm.type)); + if (e->flags & (1 << NFTNL_EXPR_OBJREF_IMM_NAME)) + mnl_attr_put_str(nlh, NFTA_OBJREF_IMM_NAME, objref->imm.name); +} + +static int nftnl_expr_objref_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_objref *objref = nftnl_expr_data(e); + struct nlattr *tb[NFTA_OBJREF_MAX + 1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_objref_cb, tb) < 0) + return -1; + + if (tb[NFTA_OBJREF_IMM_TYPE]) { + objref->imm.type = + ntohl(mnl_attr_get_u32(tb[NFTA_OBJREF_IMM_TYPE])); + e->flags |= (1 << NFTNL_EXPR_OBJREF_IMM_TYPE); + } + if (tb[NFTA_OBJREF_IMM_NAME]) { + objref->imm.name = + strdup(mnl_attr_get_str(tb[NFTA_OBJREF_IMM_NAME])); + e->flags |= (1 << NFTNL_EXPR_OBJREF_IMM_NAME); + } + + return 0; +} + +static int +nftnl_expr_objref_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + uint32_t uval32; + const char *str; + + if (nftnl_jansson_node_exist(root, "name")) { + str = nftnl_jansson_parse_str(root, "name", err); + if (str == NULL) + return -1; + + nftnl_expr_set_str(e, NFTNL_EXPR_OBJREF_IMM_NAME, str); + } + + if (nftnl_jansson_parse_val(root, "type", NFTNL_TYPE_U32, &uval32, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_OBJREF_IMM_TYPE, uval32); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int nftnl_expr_objref_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_objref *objref = nftnl_expr_data(e); + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_OBJREF_IMM_TYPE)) + nftnl_buf_u32(&b, type, objref->imm.type, BYTES); + if (e->flags & (1 << NFTNL_EXPR_OBJREF_IMM_NAME)) + nftnl_buf_str(&b, type, objref->imm.name, NAME); + + return nftnl_buf_done(&b); +} + +static int nftnl_expr_objref_snprintf_default(char *buf, size_t len, + const struct nftnl_expr *e) +{ + struct nftnl_expr_objref *objref = nftnl_expr_data(e); + + return snprintf(buf, len, "type %u name %s ", + objref->imm.type, objref->imm.name); +} + +static int nftnl_expr_objref_snprintf(char *buf, size_t len, uint32_t type, + uint32_t flags, + const struct nftnl_expr *e) +{ + switch (type) { + case NFTNL_OUTPUT_DEFAULT: + return nftnl_expr_objref_snprintf_default(buf, len, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_objref_export(buf, len, e, type); + default: + break; + } + return -1; +} + +static bool nftnl_expr_objref_cmp(const struct nftnl_expr *e1, + const struct nftnl_expr *e2) +{ + struct nftnl_expr_objref *c1 = nftnl_expr_data(e1); + struct nftnl_expr_objref *c2 = nftnl_expr_data(e2); + bool eq = true; + + if (e1->flags & (1 << NFTNL_EXPR_OBJREF_IMM_TYPE)) + eq &= (c1->imm.type == c2->imm.type); + if (e1->flags & (1 << NFTNL_EXPR_OBJREF_IMM_NAME)) + eq &= !strcmp(c1->imm.name, c2->imm.name); + + return eq; +} + +struct expr_ops expr_ops_objref = { + .name = "objref", + .alloc_len = sizeof(struct nftnl_expr_objref), + .max_attr = NFTA_OBJREF_MAX, + .cmp = nftnl_expr_objref_cmp, + .set = nftnl_expr_objref_set, + .get = nftnl_expr_objref_get, + .parse = nftnl_expr_objref_parse, + .build = nftnl_expr_objref_build, + .snprintf = nftnl_expr_objref_snprintf, + .json_parse = nftnl_expr_objref_json_parse, +}; diff --git a/src/expr_ops.c b/src/expr_ops.c index 4d7d1fa..7a0e1e3 100644 --- a/src/expr_ops.c +++ b/src/expr_ops.c @@ -21,6 +21,7 @@ extern struct expr_ops expr_ops_match; 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_objref; extern struct expr_ops expr_ops_payload; extern struct expr_ops expr_ops_range; extern struct expr_ops expr_ops_redir; @@ -67,6 +68,7 @@ static struct expr_ops *expr_ops[] = { &expr_ops_dynset, &expr_ops_hash, &expr_ops_fib, + &expr_ops_objref, NULL, }; diff --git a/src/object.c b/src/object.c index 0190e94..0d3dc2b 100644 --- a/src/object.c +++ b/src/object.c @@ -276,6 +276,7 @@ static int nftnl_jansson_parse_obj(struct nftnl_obj *t, json_t *tree, struct nftnl_parse_err *err) { const char *str; + uint32_t type; json_t *root; root = nftnl_jansson_get_node(tree, "obj", err); @@ -290,6 +291,10 @@ static int nftnl_jansson_parse_obj(struct nftnl_obj *t, json_t *tree, if (str != NULL) nftnl_obj_set_str(t, NFTNL_OBJ_NAME, str); + if (nftnl_jansson_parse_val(root, "type", NFTNL_TYPE_U32, &type, + err) < 0) + nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, type); + return 0; } #endif -- cgit v1.2.3