src: support for stateful objects

This patch allows you to add, to delete and to get stateful objects,
this support two object types: counter and quota.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 573 insertions, 0 deletions

diff --git a/src/object.c b/src/object.c
new file mode 100644
index 0000000..0190e94
--- /dev/null
+++ b/src/object.c
@@ -0,0 +1,573 @@
+/*
+ * (C) 2012-2016 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * 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 <time.h>
+#include <endian.h>
+#include <stdint.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <errno.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include <libnftnl/object.h>
+#include <buffer.h>
+#include "obj.h"
+
+static struct obj_ops *obj_ops[] = {
+	[NFT_OBJECT_COUNTER]	= &obj_ops_counter,
+	[NFT_OBJECT_QUOTA]	= &obj_ops_quota,
+};
+
+static struct obj_ops *nftnl_obj_ops_lookup(uint32_t type)
+{
+	if (type > NFT_OBJECT_QUOTA)
+		return NULL;
+
+	return obj_ops[type];
+}
+
+struct nftnl_obj *nftnl_obj_alloc(void)
+{
+	return calloc(1, sizeof(struct nftnl_obj));
+}
+EXPORT_SYMBOL(nftnl_obj_alloc);
+
+void nftnl_obj_free(const struct nftnl_obj *obj)
+{
+	if (obj->flags & (1 << NFTNL_OBJ_TABLE))
+		xfree(obj->table);
+	if (obj->flags & (1 << NFTNL_OBJ_NAME))
+		xfree(obj->name);
+
+	xfree(obj);
+}
+EXPORT_SYMBOL(nftnl_obj_free);
+
+bool nftnl_obj_is_set(const struct nftnl_obj *obj, uint16_t attr)
+{
+	return obj->flags & (1 << attr);
+}
+EXPORT_SYMBOL(nftnl_obj_is_set);
+
+static uint32_t nftnl_obj_validate[NFTNL_OBJ_MAX + 1] = {
+	[NFTNL_OBJ_FAMILY]	= sizeof(uint32_t),
+	[NFTNL_OBJ_USE]		= sizeof(uint32_t),
+};
+
+void nftnl_obj_set_data(struct nftnl_obj *obj, uint16_t attr,
+			const void *data, uint32_t data_len)
+{
+	if (attr < NFTNL_OBJ_MAX)
+		nftnl_assert_validate(data, nftnl_obj_validate, attr, data_len);
+
+	switch (attr) {
+	case NFTNL_OBJ_TABLE:
+		xfree(obj->table);
+		obj->table = strdup(data);
+		break;
+	case NFTNL_OBJ_NAME:
+		xfree(obj->name);
+		obj->name = strdup(data);
+		break;
+	case NFTNL_OBJ_TYPE:
+		obj->ops = nftnl_obj_ops_lookup(*((uint32_t *)data));
+		break;
+	case NFTNL_OBJ_FAMILY:
+		obj->family = *((uint32_t *)data);
+		break;
+	case NFTNL_OBJ_USE:
+		obj->use = *((uint32_t *)data);
+		break;
+	default:
+		if (obj->ops)
+			obj->ops->set(obj, attr, data, data_len);
+		break;
+	}
+	obj->flags |= (1 << attr);
+}
+EXPORT_SYMBOL(nftnl_obj_set_data);
+
+void nftnl_obj_set(struct nftnl_obj *obj, uint16_t attr, const void *data)
+{
+	nftnl_obj_set_data(obj, attr, data, nftnl_obj_validate[attr]);
+}
+EXPORT_SYMBOL(nftnl_obj_set);
+
+void nftnl_obj_set_u32(struct nftnl_obj *obj, uint16_t attr, uint32_t val)
+{
+	nftnl_obj_set_data(obj, attr, &val, sizeof(uint32_t));
+}
+EXPORT_SYMBOL(nftnl_obj_set_u32);
+
+void nftnl_obj_set_u64(struct nftnl_obj *obj, uint16_t attr, uint64_t val)
+{
+	nftnl_obj_set_data(obj, attr, &val, sizeof(uint64_t));
+}
+EXPORT_SYMBOL(nftnl_obj_set_u64);
+
+void nftnl_obj_set_str(struct nftnl_obj *obj, uint16_t attr, const char *str)
+{
+	nftnl_obj_set_data(obj, attr, str, 0);
+}
+EXPORT_SYMBOL(nftnl_obj_set_str);
+
+const void *nftnl_obj_get_data(struct nftnl_obj *obj, uint16_t attr,
+			       uint32_t *data_len)
+{
+	if (!(obj->flags & (1 << attr)))
+		return NULL;
+
+	switch(attr) {
+	case NFTNL_OBJ_TABLE:
+		return obj->table;
+	case NFTNL_OBJ_NAME:
+		return obj->name;
+	case NFTNL_OBJ_TYPE:
+		if (!obj->ops)
+			return NULL;
+
+		*data_len = sizeof(uint32_t);
+		return &obj->ops->type;
+	case NFTNL_OBJ_FAMILY:
+		*data_len = sizeof(uint32_t);
+		return &obj->family;
+	case NFTNL_OBJ_USE:
+		*data_len = sizeof(uint32_t);
+		return &obj->use;
+	default:
+		if (obj->ops)
+			return obj->ops->get(obj, attr, data_len);
+		break;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(nftnl_obj_get_data);
+
+const void *nftnl_obj_get(struct nftnl_obj *obj, uint16_t attr)
+{
+	uint32_t data_len;
+	return nftnl_obj_get_data(obj, attr, &data_len);
+}
+EXPORT_SYMBOL(nftnl_obj_get);
+
+uint32_t nftnl_obj_get_u32(struct nftnl_obj *obj, uint16_t attr)
+{
+	const void *ret = nftnl_obj_get(obj, attr);
+	return ret == NULL ? 0 : *((uint32_t *)ret);
+}
+EXPORT_SYMBOL(nftnl_obj_get_u32);
+
+uint64_t nftnl_obj_get_u64(struct nftnl_obj *obj, uint16_t attr)
+{
+	const void *ret = nftnl_obj_get(obj, attr);
+	return ret == NULL ? 0 : *((uint64_t *)ret);
+}
+EXPORT_SYMBOL(nftnl_obj_get_u64);
+
+const char *nftnl_obj_get_str(struct nftnl_obj *obj, uint16_t attr)
+{
+	return nftnl_obj_get(obj, attr);
+}
+EXPORT_SYMBOL(nftnl_obj_get_str);
+
+void nftnl_obj_nlmsg_build_payload(struct nlmsghdr *nlh,
+				   const struct nftnl_obj *obj)
+{
+	if (obj->flags & (1 << NFTNL_OBJ_TABLE))
+		mnl_attr_put_strz(nlh, NFTA_OBJ_TABLE, obj->table);
+	if (obj->flags & (1 << NFTNL_OBJ_NAME))
+		mnl_attr_put_strz(nlh, NFTA_OBJ_NAME, obj->name);
+	if (obj->flags & (1 << NFTNL_OBJ_TYPE))
+		mnl_attr_put_u32(nlh, NFTA_OBJ_TYPE, htonl(obj->ops->type));
+
+	if (obj->ops) {
+		struct nlattr *nest = mnl_attr_nest_start(nlh, NFTA_OBJ_DATA);
+
+		obj->ops->build(nlh, obj);
+		mnl_attr_nest_end(nlh, nest);
+	}
+}
+EXPORT_SYMBOL(nftnl_obj_nlmsg_build_payload);
+
+static int nftnl_obj_parse_attr_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_OBJ_MAX) < 0)
+		return MNL_CB_OK;
+
+	switch(type) {
+	case NFTA_OBJ_TABLE:
+	case NFTA_OBJ_NAME:
+		if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
+			abi_breakage();
+		break;
+	case NFTA_OBJ_DATA:
+		if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0)
+			abi_breakage();
+		break;
+	case NFTA_OBJ_USE:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+			abi_breakage();
+		break;
+	}
+
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+int nftnl_obj_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_obj *obj)
+{
+	struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
+	struct nlattr *tb[NFTA_OBJ_MAX + 1] = {};
+	int err;
+
+	if (mnl_attr_parse(nlh, sizeof(*nfg), nftnl_obj_parse_attr_cb, tb) < 0)
+		return -1;
+
+	if (tb[NFTA_OBJ_TABLE]) {
+		obj->table = strdup(mnl_attr_get_str(tb[NFTA_OBJ_TABLE]));
+		obj->flags |= (1 << NFTNL_OBJ_TABLE);
+	}
+	if (tb[NFTA_OBJ_NAME]) {
+		obj->name = strdup(mnl_attr_get_str(tb[NFTA_OBJ_NAME]));
+		obj->flags |= (1 << NFTNL_OBJ_NAME);
+	}
+	if (tb[NFTA_OBJ_TYPE]) {
+		uint32_t type = ntohl(mnl_attr_get_u32(tb[NFTA_OBJ_TYPE]));
+
+		obj->ops = nftnl_obj_ops_lookup(type);
+		obj->flags |= (1 << NFTNL_OBJ_TYPE);
+	}
+	if (tb[NFTA_OBJ_DATA]) {
+		if (obj->ops) {
+			err = obj->ops->parse(obj, tb[NFTA_OBJ_DATA]);
+			if (err < 0)
+				return err;
+		}
+	}
+	if (tb[NFTA_OBJ_USE]) {
+		obj->use = ntohl(mnl_attr_get_u32(tb[NFTA_OBJ_USE]));
+		obj->flags |= (1 << NFTNL_OBJ_USE);
+	}
+
+	obj->family = nfg->nfgen_family;
+	obj->flags |= (1 << NFTNL_OBJ_FAMILY);
+
+	return 0;
+}
+EXPORT_SYMBOL(nftnl_obj_nlmsg_parse);
+
+#ifdef JSON_PARSING
+static int nftnl_jansson_parse_obj(struct nftnl_obj *t, json_t *tree,
+			    struct nftnl_parse_err *err)
+{
+	const char *str;
+	json_t *root;
+
+	root = nftnl_jansson_get_node(tree, "obj", err);
+	if (root == NULL)
+		return -1;
+
+	str = nftnl_jansson_parse_str(root, "table", err);
+	if (str != NULL)
+		nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, str);
+
+	str = nftnl_jansson_parse_str(root, "name", err);
+	if (str != NULL)
+		nftnl_obj_set_str(t, NFTNL_OBJ_NAME, str);
+
+	return 0;
+}
+#endif
+
+static int nftnl_obj_json_parse(struct nftnl_obj *t, const void *json,
+				struct nftnl_parse_err *err,
+				enum nftnl_parse_input input)
+{
+#ifdef JSON_PARSING
+	json_t *tree;
+	json_error_t error;
+	int ret;
+
+	tree = nftnl_jansson_create_root(json, &error, err, input);
+	if (tree == NULL)
+		return -1;
+
+	ret = nftnl_jansson_parse_obj(t, tree, err);
+
+	nftnl_jansson_free_root(tree);
+
+	return ret;
+#else
+	errno = EOPNOTSUPP;
+	return -1;
+#endif
+}
+
+static int nftnl_obj_do_parse(struct nftnl_obj *obj, enum nftnl_parse_type type,
+			      const void *data, struct nftnl_parse_err *err,
+			      enum nftnl_parse_input input)
+{
+	struct nftnl_parse_err perr;
+	int ret;
+
+	switch (type) {
+	case NFTNL_PARSE_JSON:
+		ret = nftnl_obj_json_parse(obj, data, &perr, input);
+		break;
+	case NFTNL_PARSE_XML:
+	default:
+		ret = -1;
+		errno = EOPNOTSUPP;
+		break;
+	}
+
+	if (err != NULL)
+		*err = perr;
+
+	return ret;
+}
+
+int nftnl_obj_parse(struct nftnl_obj *obj, enum nftnl_parse_type type,
+		      const char *data, struct nftnl_parse_err *err)
+{
+	return nftnl_obj_do_parse(obj, type, data, err, NFTNL_PARSE_BUFFER);
+}
+EXPORT_SYMBOL(nftnl_obj_parse);
+
+int nftnl_obj_parse_file(struct nftnl_obj *obj, enum nftnl_parse_type type,
+			   FILE *fp, struct nftnl_parse_err *err)
+{
+	return nftnl_obj_do_parse(obj, type, fp, err, NFTNL_PARSE_FILE);
+}
+EXPORT_SYMBOL(nftnl_obj_parse_file);
+
+static int nftnl_obj_export(char *buf, size_t size,
+			    const struct nftnl_obj *obj,
+			    uint32_t type, uint32_t flags)
+{
+	int ret = 0;
+
+	NFTNL_BUF_INIT(b, buf, size);
+
+	nftnl_buf_open(&b, type, TABLE);
+	if (obj->flags & (1 << NFTNL_OBJ_TABLE))
+		nftnl_buf_str(&b, type, obj->name, NAME);
+	if (obj->flags & (1 << NFTNL_OBJ_NAME))
+		nftnl_buf_str(&b, type, obj->name, NAME);
+	if (obj->flags & (1 << NFTNL_OBJ_FAMILY))
+		nftnl_buf_str(&b, type, nftnl_family2str(obj->family), FAMILY);
+	if (obj->flags & (1 << NFTNL_OBJ_USE))
+		nftnl_buf_u32(&b, type, obj->use, USE);
+
+	if (obj->ops)
+		ret = obj->ops->snprintf(buf + b.len, size - b.len, type,
+					 flags, obj);
+
+	b.len += ret;
+	nftnl_buf_close(&b, type, TABLE);
+
+	return nftnl_buf_done(&b);
+}
+
+static int nftnl_obj_snprintf_dflt(char *buf, size_t size,
+				   const struct nftnl_obj *obj,
+				   uint32_t type, uint32_t flags)
+{
+	int ret, len = size, offset = 0;
+
+	ret = snprintf(buf, size, "table %s name %s use %u [ %s ",
+		       obj->table, obj->name, obj->use, obj->ops->name);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	if (obj->ops) {
+		ret = obj->ops->snprintf(buf + offset, offset, type, flags, obj);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+	ret = snprintf(buf + offset, offset, "]");
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	return offset;
+}
+
+static int nftnl_obj_cmd_snprintf(char *buf, size_t size,
+				    const struct nftnl_obj *obj, uint32_t cmd,
+				    uint32_t type, uint32_t flags)
+{
+	int ret, len = size, offset = 0;
+
+	ret = nftnl_cmd_header_snprintf(buf + offset, len, cmd, type, flags);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	switch (type) {
+	case NFT_OUTPUT_DEFAULT:
+		ret = nftnl_obj_snprintf_dflt(buf + offset, len, obj, type,
+					      flags);
+		break;
+	case NFT_OUTPUT_JSON:
+		ret = nftnl_obj_export(buf + offset, len, obj, type, flags);
+		break;
+	case NFT_OUTPUT_XML:
+	default:
+		return -1;
+	}
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	ret = nftnl_cmd_footer_snprintf(buf + offset, len, cmd, type, flags);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	return offset;
+}
+
+int nftnl_obj_snprintf(char *buf, size_t size, const struct nftnl_obj *obj,
+		       uint32_t type, uint32_t flags)
+{
+	return nftnl_obj_cmd_snprintf(buf, size, obj, nftnl_flag2cmd(flags),
+				      type, flags);
+}
+EXPORT_SYMBOL(nftnl_obj_snprintf);
+
+static int nftnl_obj_do_snprintf(char *buf, size_t size, const void *obj,
+				 uint32_t cmd, uint32_t type, uint32_t flags)
+{
+	return nftnl_obj_snprintf(buf, size, obj, type, flags);
+}
+
+int nftnl_obj_fprintf(FILE *fp, const struct nftnl_obj *obj, uint32_t type,
+		      uint32_t flags)
+{
+	return nftnl_fprintf(fp, obj, NFT_CMD_UNSPEC, type, flags,
+			     nftnl_obj_do_snprintf);
+}
+EXPORT_SYMBOL(nftnl_obj_fprintf);
+
+struct nftnl_obj_list {
+	struct list_head list;
+};
+
+struct nftnl_obj_list *nftnl_obj_list_alloc(void)
+{
+	struct nftnl_obj_list *list;
+
+	list = calloc(1, sizeof(struct nftnl_obj_list));
+	if (list == NULL)
+		return NULL;
+
+	INIT_LIST_HEAD(&list->list);
+
+	return list;
+}
+EXPORT_SYMBOL(nftnl_obj_list_alloc);
+
+void nftnl_obj_list_free(struct nftnl_obj_list *list)
+{
+	struct nftnl_obj *r, *tmp;
+
+	list_for_each_entry_safe(r, tmp, &list->list, head) {
+		list_del(&r->head);
+		nftnl_obj_free(r);
+	}
+	xfree(list);
+}
+EXPORT_SYMBOL(nftnl_obj_list_free);
+
+int nftnl_obj_list_is_empty(struct nftnl_obj_list *list)
+{
+	return list_empty(&list->list);
+}
+EXPORT_SYMBOL(nftnl_obj_list_is_empty);
+
+void nftnl_obj_list_add(struct nftnl_obj *r, struct nftnl_obj_list *list)
+{
+	list_add(&r->head, &list->list);
+}
+EXPORT_SYMBOL(nftnl_obj_list_add);
+
+void nftnl_obj_list_add_tail(struct nftnl_obj *r,
+			       struct nftnl_obj_list *list)
+{
+	list_add_tail(&r->head, &list->list);
+}
+EXPORT_SYMBOL(nftnl_obj_list_add_tail);
+
+void nftnl_obj_list_del(struct nftnl_obj *t)
+{
+	list_del(&t->head);
+}
+EXPORT_SYMBOL(nftnl_obj_list_del);
+
+int nftnl_obj_list_foreach(struct nftnl_obj_list *table_list,
+			     int (*cb)(struct nftnl_obj *t, void *data),
+			     void *data)
+{
+	struct nftnl_obj *cur, *tmp;
+	int ret;
+
+	list_for_each_entry_safe(cur, tmp, &table_list->list, head) {
+		ret = cb(cur, data);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(nftnl_obj_list_foreach);
+
+struct nftnl_obj_list_iter {
+	struct nftnl_obj_list	*list;
+	struct nftnl_obj	*cur;
+};
+
+struct nftnl_obj_list_iter *
+nftnl_obj_list_iter_create(struct nftnl_obj_list *l)
+{
+	struct nftnl_obj_list_iter *iter;
+
+	iter = calloc(1, sizeof(struct nftnl_obj_list_iter));
+	if (iter == NULL)
+		return NULL;
+
+	iter->list = l;
+	if (nftnl_obj_list_is_empty(l))
+		iter->cur = NULL;
+	else
+		iter->cur = list_entry(l->list.next, struct nftnl_obj, head);
+
+	return iter;
+}
+EXPORT_SYMBOL(nftnl_obj_list_iter_create);
+
+struct nftnl_obj *nftnl_obj_list_iter_next(struct nftnl_obj_list_iter *iter)
+{
+	struct nftnl_obj *r = iter->cur;
+
+	if (r == NULL)
+		return NULL;
+
+	/* get next table, if any */
+	iter->cur = list_entry(iter->cur->head.next, struct nftnl_obj, head);
+	if (&iter->cur->head == iter->list->list.next)
+		return NULL;
+
+	return r;
+}
+EXPORT_SYMBOL(nftnl_obj_list_iter_next);
+
+void nftnl_obj_list_iter_destroy(struct nftnl_obj_list_iter *iter)
+{
+	xfree(iter);
+}
+EXPORT_SYMBOL(nftnl_obj_list_iter_destroy);