netfilter: nftables: netlink support for several set element expressions

This patch adds three new netlink attributes to encapsulate a list of
expressions per set elements:

- NFTA_SET_EXPRESSIONS: this attribute provides the set definition in
  terms of expressions. New set elements get attached the list of
  expressions that is specified by this new netlink attribute.
- NFTA_SET_ELEM_EXPRESSIONS: this attribute allows users to restore (or
  initialize) the stateful information of set elements when adding an
  element to the set.
- NFTA_DYNSET_EXPRESSIONS: this attribute specifies the list of
  expressions that the set element gets when it is inserted from the
  packet path.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2020-12-07 17:37:14 +01:00
Родитель 563125a73a
Коммит 48b0ae046e
3 изменённых файлов: 149 добавлений и 6 удалений

Просмотреть файл

@ -361,6 +361,7 @@ enum nft_set_field_attributes {
* @NFTA_SET_OBJ_TYPE: stateful object type (NLA_U32: NFT_OBJECT_*)
* @NFTA_SET_HANDLE: set handle (NLA_U64)
* @NFTA_SET_EXPR: set expression (NLA_NESTED: nft_expr_attributes)
* @NFTA_SET_EXPRESSIONS: list of expressions (NLA_NESTED: nft_list_attributes)
*/
enum nft_set_attributes {
NFTA_SET_UNSPEC,
@ -381,6 +382,7 @@ enum nft_set_attributes {
NFTA_SET_OBJ_TYPE,
NFTA_SET_HANDLE,
NFTA_SET_EXPR,
NFTA_SET_EXPRESSIONS,
__NFTA_SET_MAX
};
#define NFTA_SET_MAX (__NFTA_SET_MAX - 1)
@ -406,6 +408,7 @@ enum nft_set_elem_flags {
* @NFTA_SET_ELEM_EXPR: expression (NLA_NESTED: nft_expr_attributes)
* @NFTA_SET_ELEM_OBJREF: stateful object reference (NLA_STRING)
* @NFTA_SET_ELEM_KEY_END: closing key value (NLA_NESTED: nft_data)
* @NFTA_SET_ELEM_EXPRESSIONS: list of expressions (NLA_NESTED: nft_list_attributes)
*/
enum nft_set_elem_attributes {
NFTA_SET_ELEM_UNSPEC,
@ -419,6 +422,7 @@ enum nft_set_elem_attributes {
NFTA_SET_ELEM_PAD,
NFTA_SET_ELEM_OBJREF,
NFTA_SET_ELEM_KEY_END,
NFTA_SET_ELEM_EXPRESSIONS,
__NFTA_SET_ELEM_MAX
};
#define NFTA_SET_ELEM_MAX (__NFTA_SET_ELEM_MAX - 1)
@ -715,6 +719,7 @@ enum nft_dynset_flags {
* @NFTA_DYNSET_TIMEOUT: timeout value for the new element (NLA_U64)
* @NFTA_DYNSET_EXPR: expression (NLA_NESTED: nft_expr_attributes)
* @NFTA_DYNSET_FLAGS: flags (NLA_U32)
* @NFTA_DYNSET_EXPRESSIONS: list of expressions (NLA_NESTED: nft_list_attributes)
*/
enum nft_dynset_attributes {
NFTA_DYNSET_UNSPEC,
@ -727,6 +732,7 @@ enum nft_dynset_attributes {
NFTA_DYNSET_EXPR,
NFTA_DYNSET_PAD,
NFTA_DYNSET_FLAGS,
NFTA_DYNSET_EXPRESSIONS,
__NFTA_DYNSET_MAX,
};
#define NFTA_DYNSET_MAX (__NFTA_DYNSET_MAX - 1)

Просмотреть файл

@ -3566,6 +3566,7 @@ static const struct nla_policy nft_set_policy[NFTA_SET_MAX + 1] = {
[NFTA_SET_OBJ_TYPE] = { .type = NLA_U32 },
[NFTA_SET_HANDLE] = { .type = NLA_U64 },
[NFTA_SET_EXPR] = { .type = NLA_NESTED },
[NFTA_SET_EXPRESSIONS] = { .type = NLA_NESTED },
};
static const struct nla_policy nft_set_desc_policy[NFTA_SET_DESC_MAX + 1] = {
@ -3773,6 +3774,7 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
u32 portid = ctx->portid;
struct nlattr *nest;
u32 seq = ctx->seq;
int i;
event = nfnl_msg_type(NFNL_SUBSYS_NFTABLES, event);
nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct nfgenmsg),
@ -3847,6 +3849,17 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
goto nla_put_failure;
nla_nest_end(skb, nest);
} else if (set->num_exprs > 1) {
nest = nla_nest_start_noflag(skb, NFTA_SET_EXPRESSIONS);
if (nest == NULL)
goto nla_put_failure;
for (i = 0; i < set->num_exprs; i++) {
if (nft_expr_dump(skb, NFTA_LIST_ELEM,
set->exprs[i]) < 0)
goto nla_put_failure;
}
nla_nest_end(skb, nest);
}
nlmsg_end(skb, nlh);
@ -4215,7 +4228,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
return err;
}
if (nla[NFTA_SET_EXPR])
if (nla[NFTA_SET_EXPR] || nla[NFTA_SET_EXPRESSIONS])
desc.expr = true;
table = nft_table_lookup(net, nla[NFTA_SET_TABLE], family, genmask);
@ -4281,6 +4294,29 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
}
set->exprs[0] = expr;
set->num_exprs++;
} else if (nla[NFTA_SET_EXPRESSIONS]) {
struct nft_expr *expr;
struct nlattr *tmp;
int left;
i = 0;
nla_for_each_nested(tmp, nla[NFTA_SET_EXPRESSIONS], left) {
if (i == NFT_SET_EXPR_MAX) {
err = -E2BIG;
goto err_set_init;
}
if (nla_type(tmp) != NFTA_LIST_ELEM) {
err = -EINVAL;
goto err_set_init;
}
expr = nft_set_elem_expr_alloc(&ctx, set, tmp);
if (IS_ERR(expr)) {
err = PTR_ERR(expr);
goto err_set_init;
}
set->exprs[i++] = expr;
set->num_exprs++;
}
}
udata = NULL;
@ -4540,6 +4576,7 @@ static const struct nla_policy nft_set_elem_policy[NFTA_SET_ELEM_MAX + 1] = {
[NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING,
.len = NFT_OBJ_MAXNAMELEN - 1 },
[NFTA_SET_ELEM_KEY_END] = { .type = NLA_NESTED },
[NFTA_SET_ELEM_EXPRESSIONS] = { .type = NLA_NESTED },
};
static const struct nla_policy nft_set_elem_list_policy[NFTA_SET_ELEM_LIST_MAX + 1] = {
@ -4580,6 +4617,7 @@ static int nft_set_elem_expr_dump(struct sk_buff *skb,
struct nft_set_elem_expr *elem_expr;
u32 size, num_exprs = 0;
struct nft_expr *expr;
struct nlattr *nest;
elem_expr = nft_set_ext_expr(ext);
nft_setelem_expr_foreach(expr, elem_expr, size)
@ -4591,9 +4629,22 @@ static int nft_set_elem_expr_dump(struct sk_buff *skb,
return -1;
return 0;
}
} else if (num_exprs > 1) {
nest = nla_nest_start_noflag(skb, NFTA_SET_ELEM_EXPRESSIONS);
if (nest == NULL)
goto nla_put_failure;
nft_setelem_expr_foreach(expr, elem_expr, size) {
expr = nft_setelem_expr_at(elem_expr, size);
if (nft_expr_dump(skb, NFTA_LIST_ELEM, expr) < 0)
goto nla_put_failure;
}
nla_nest_end(skb, nest);
}
return 0;
nla_put_failure:
return -1;
}
static int nf_tables_fill_setelem(struct sk_buff *skb,
@ -5268,7 +5319,8 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
nla[NFTA_SET_ELEM_TIMEOUT] ||
nla[NFTA_SET_ELEM_EXPIRATION] ||
nla[NFTA_SET_ELEM_USERDATA] ||
nla[NFTA_SET_ELEM_EXPR]))
nla[NFTA_SET_ELEM_EXPR] ||
nla[NFTA_SET_ELEM_EXPRESSIONS]))
return -EINVAL;
timeout = 0;
@ -5310,6 +5362,41 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
err = -EOPNOTSUPP;
goto err_set_elem_expr;
}
} else if (nla[NFTA_SET_ELEM_EXPRESSIONS]) {
struct nft_expr *expr;
struct nlattr *tmp;
int left;
if (set->num_exprs == 0)
return -EOPNOTSUPP;
i = 0;
nla_for_each_nested(tmp, nla[NFTA_SET_ELEM_EXPRESSIONS], left) {
if (i == set->num_exprs) {
err = -E2BIG;
goto err_set_elem_expr;
}
if (nla_type(tmp) != NFTA_LIST_ELEM) {
err = -EINVAL;
goto err_set_elem_expr;
}
expr = nft_set_elem_expr_alloc(ctx, set, tmp);
if (IS_ERR(expr)) {
err = PTR_ERR(expr);
goto err_set_elem_expr;
}
expr_array[i] = expr;
if (expr->ops != set->exprs[i]->ops) {
err = -EOPNOTSUPP;
goto err_set_elem_expr;
}
i++;
}
if (set->num_exprs != i) {
err = -EOPNOTSUPP;
goto err_set_elem_expr;
}
} else if (set->num_exprs > 0) {
err = nft_set_elem_expr_clone(ctx, set, expr_array);
if (err < 0)

Просмотреть файл

@ -153,6 +153,7 @@ static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
[NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
[NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
[NFTA_DYNSET_EXPRESSIONS] = { .type = NLA_NESTED },
};
static int nft_dynset_init(const struct nft_ctx *ctx,
@ -232,12 +233,13 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
} else if (set->flags & NFT_SET_MAP)
return -EINVAL;
if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) &&
!(set->flags & NFT_SET_EVAL))
return -EINVAL;
if (tb[NFTA_DYNSET_EXPR]) {
struct nft_expr *dynset_expr;
if (!(set->flags & NFT_SET_EVAL))
return -EINVAL;
dynset_expr = nft_dynset_expr_alloc(ctx, set,
tb[NFTA_DYNSET_EXPR], 0);
if (IS_ERR(dynset_expr))
@ -252,6 +254,40 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
err = -EOPNOTSUPP;
goto err_expr_free;
}
} else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
struct nft_expr *dynset_expr;
struct nlattr *tmp;
int left;
i = 0;
nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
if (i == NFT_SET_EXPR_MAX) {
err = -E2BIG;
goto err_expr_free;
}
if (nla_type(tmp) != NFTA_LIST_ELEM) {
err = -EINVAL;
goto err_expr_free;
}
dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i);
if (IS_ERR(dynset_expr)) {
err = PTR_ERR(dynset_expr);
goto err_expr_free;
}
priv->expr_array[i] = dynset_expr;
priv->num_exprs++;
if (set->num_exprs &&
dynset_expr->ops != set->exprs[i]->ops) {
err = -EOPNOTSUPP;
goto err_expr_free;
}
i++;
}
if (set->num_exprs && set->num_exprs != i) {
err = -EOPNOTSUPP;
goto err_expr_free;
}
}
nft_set_ext_prepare(&priv->tmpl);
@ -318,6 +354,7 @@ static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_dynset *priv = nft_expr_priv(expr);
u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
int i;
if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
goto nla_put_failure;
@ -335,6 +372,19 @@ static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
if (priv->num_exprs == 1) {
if (nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr_array[0]))
goto nla_put_failure;
} else if (priv->num_exprs > 1) {
struct nlattr *nest;
nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS);
if (!nest)
goto nla_put_failure;
for (i = 0; i < priv->num_exprs; i++) {
if (nft_expr_dump(skb, NFTA_LIST_ELEM,
priv->expr_array[i]))
goto nla_put_failure;
}
nla_nest_end(skb, nest);
}
if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
goto nla_put_failure;