struct list_head head;
struct nft_expr_ops ops;
unsigned int refcnt;
+
+ /* Unlike other expressions, ops doesn't have static storage duration.
+ * nft core assumes they do. We use kfree_rcu so that nft core can
+ * can check expr->ops->size even after nft_compat->destroy() frees
+ * the nft_xt struct that holds the ops structure.
+ */
+ struct rcu_head rcu_head;
+};
+
+/* Used for matches where *info is larger than X byte */
+#define NFT_MATCH_LARGE_THRESH 192
+
+struct nft_xt_match_priv {
+ void *info;
};
-static void nft_xt_put(struct nft_xt *xt)
+static bool nft_xt_put(struct nft_xt *xt)
{
if (--xt->refcnt == 0) {
list_del(&xt->head);
- kfree(xt);
+ kfree_rcu(xt, rcu_head);
+ return true;
}
+
+ return false;
}
static int nft_compat_chain_validate_dependency(const char *tablename,
struct xt_target *target = expr->ops->data;
struct xt_tgchk_param par;
size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
+ struct nft_xt *nft_xt;
u16 proto = 0;
bool inv = false;
union nft_entry e = {};
if (ctx->nla[NFTA_RULE_COMPAT]) {
ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
if (ret < 0)
- goto err;
+ return ret;
}
nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
ret = xt_check_target(&par, size, proto, inv);
if (ret < 0)
- goto err;
+ return ret;
/* The standard target cannot be used */
- if (target->target == NULL) {
- ret = -EINVAL;
- goto err;
- }
+ if (!target->target)
+ return -EINVAL;
+ nft_xt = container_of(expr->ops, struct nft_xt, ops);
+ nft_xt->refcnt++;
return 0;
-err:
- module_put(target->me);
- return ret;
}
static void
if (par.target->destroy != NULL)
par.target->destroy(&par);
- nft_xt_put(container_of(expr->ops, struct nft_xt, ops));
- module_put(target->me);
+ if (nft_xt_put(container_of(expr->ops, struct nft_xt, ops)))
+ module_put(target->me);
}
static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
return 0;
}
-static void nft_match_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_pktinfo *pkt)
+static void __nft_match_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt,
+ void *info)
{
- void *info = nft_expr_priv(expr);
struct xt_match *match = expr->ops->data;
struct sk_buff *skb = pkt->skb;
bool ret;
}
}
+static void nft_match_large_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_xt_match_priv *priv = nft_expr_priv(expr);
+
+ __nft_match_eval(expr, regs, pkt, priv->info);
+}
+
+static void nft_match_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr));
+}
+
static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
[NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
[NFTA_MATCH_REV] = { .type = NLA_U32 },
}
static int
-nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
- const struct nlattr * const tb[])
+__nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[],
+ void *info)
{
- void *info = nft_expr_priv(expr);
struct xt_match *match = expr->ops->data;
struct xt_mtchk_param par;
size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
+ struct nft_xt *nft_xt;
u16 proto = 0;
bool inv = false;
union nft_entry e = {};
if (ctx->nla[NFTA_RULE_COMPAT]) {
ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
if (ret < 0)
- goto err;
+ return ret;
}
nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
ret = xt_check_match(&par, size, proto, inv);
if (ret < 0)
- goto err;
+ return ret;
+ nft_xt = container_of(expr->ops, struct nft_xt, ops);
+ nft_xt->refcnt++;
return 0;
-err:
- module_put(match->me);
+}
+
+static int
+nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr));
+}
+
+static int
+nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_xt_match_priv *priv = nft_expr_priv(expr);
+ struct xt_match *m = expr->ops->data;
+ int ret;
+
+ priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL);
+ if (!priv->info)
+ return -ENOMEM;
+
+ ret = __nft_match_init(ctx, expr, tb, priv->info);
+ if (ret)
+ kfree(priv->info);
return ret;
}
static void
-nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
+__nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ void *info)
{
struct xt_match *match = expr->ops->data;
- void *info = nft_expr_priv(expr);
struct xt_mtdtor_param par;
par.net = ctx->net;
if (par.match->destroy != NULL)
par.match->destroy(&par);
- nft_xt_put(container_of(expr->ops, struct nft_xt, ops));
- module_put(match->me);
+ if (nft_xt_put(container_of(expr->ops, struct nft_xt, ops)))
+ module_put(match->me);
}
-static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
+static void
+nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
+{
+ __nft_match_destroy(ctx, expr, nft_expr_priv(expr));
+}
+
+static void
+nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
+{
+ struct nft_xt_match_priv *priv = nft_expr_priv(expr);
+
+ __nft_match_destroy(ctx, expr, priv->info);
+ kfree(priv->info);
+}
+
+static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr,
+ void *info)
{
- void *info = nft_expr_priv(expr);
struct xt_match *match = expr->ops->data;
if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
return -1;
}
+static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ return __nft_match_dump(skb, expr, nft_expr_priv(expr));
+}
+
+static int nft_match_large_dump(struct sk_buff *skb, const struct nft_expr *e)
+{
+ struct nft_xt_match_priv *priv = nft_expr_priv(e);
+
+ return __nft_match_dump(skb, e, priv->info);
+}
+
static int nft_match_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
struct nft_xt *nft_match;
struct xt_match *match;
+ unsigned int matchsize;
char *mt_name;
u32 rev, family;
int err;
list_for_each_entry(nft_match, &nft_match_list, head) {
struct xt_match *match = nft_match->ops.data;
- if (nft_match_cmp(match, mt_name, rev, family)) {
- if (!try_module_get(match->me))
- return ERR_PTR(-ENOENT);
-
- nft_match->refcnt++;
+ if (nft_match_cmp(match, mt_name, rev, family))
return &nft_match->ops;
- }
}
match = xt_request_find_match(family, mt_name, rev);
goto err;
}
- nft_match->refcnt = 1;
+ nft_match->refcnt = 0;
nft_match->ops.type = &nft_match_type;
- nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
nft_match->ops.eval = nft_match_eval;
nft_match->ops.init = nft_match_init;
nft_match->ops.destroy = nft_match_destroy;
nft_match->ops.validate = nft_match_validate;
nft_match->ops.data = match;
+ matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
+ if (matchsize > NFT_MATCH_LARGE_THRESH) {
+ matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv));
+
+ nft_match->ops.eval = nft_match_large_eval;
+ nft_match->ops.init = nft_match_large_init;
+ nft_match->ops.destroy = nft_match_large_destroy;
+ nft_match->ops.dump = nft_match_large_dump;
+ }
+
+ nft_match->ops.size = matchsize;
+
list_add(&nft_match->head, &nft_match_list);
return &nft_match->ops;
list_for_each_entry(nft_target, &nft_target_list, head) {
struct xt_target *target = nft_target->ops.data;
- if (nft_target_cmp(target, tg_name, rev, family)) {
- if (!try_module_get(target->me))
- return ERR_PTR(-ENOENT);
-
- nft_target->refcnt++;
+ if (nft_target_cmp(target, tg_name, rev, family))
return &nft_target->ops;
- }
}
target = xt_request_find_target(family, tg_name, rev);
goto err;
}
- nft_target->refcnt = 1;
+ nft_target->refcnt = 0;
nft_target->ops.type = &nft_target_type;
nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
nft_target->ops.init = nft_target_init;
static void __exit nft_compat_module_exit(void)
{
+ struct nft_xt *xt, *next;
+
+ /* list should be empty here, it can be non-empty only in case there
+ * was an error that caused nft_xt expr to not be initialized fully
+ * and noone else requested the same expression later.
+ *
+ * In this case, the lists contain 0-refcount entries that still
+ * hold module reference.
+ */
+ list_for_each_entry_safe(xt, next, &nft_target_list, head) {
+ struct xt_target *target = xt->ops.data;
+
+ if (WARN_ON_ONCE(xt->refcnt))
+ continue;
+ module_put(target->me);
+ kfree(xt);
+ }
+
+ list_for_each_entry_safe(xt, next, &nft_match_list, head) {
+ struct xt_match *match = xt->ops.data;
+
+ if (WARN_ON_ONCE(xt->refcnt))
+ continue;
+ module_put(match->me);
+ kfree(xt);
+ }
nfnetlink_subsys_unregister(&nfnl_compat_subsys);
nft_unregister_expr(&nft_target_type);
nft_unregister_expr(&nft_match_type);
projects / mirror_ubuntu-bionic-kernel.git / blobdiff