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-rw-r--r--net/netfilter/nft_bitwise.c533
1 files changed, 533 insertions, 0 deletions
diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c
new file mode 100644
index 000000000..b84312df9
--- /dev/null
+++ b/net/netfilter/nft_bitwise.c
@@ -0,0 +1,533 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_offload.h>
+
+struct nft_bitwise {
+ u8 sreg;
+ u8 dreg;
+ enum nft_bitwise_ops op:8;
+ u8 len;
+ struct nft_data mask;
+ struct nft_data xor;
+ struct nft_data data;
+};
+
+static void nft_bitwise_eval_bool(u32 *dst, const u32 *src,
+ const struct nft_bitwise *priv)
+{
+ unsigned int i;
+
+ for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++)
+ dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
+}
+
+static void nft_bitwise_eval_lshift(u32 *dst, const u32 *src,
+ const struct nft_bitwise *priv)
+{
+ u32 shift = priv->data.data[0];
+ unsigned int i;
+ u32 carry = 0;
+
+ for (i = DIV_ROUND_UP(priv->len, sizeof(u32)); i > 0; i--) {
+ dst[i - 1] = (src[i - 1] << shift) | carry;
+ carry = src[i - 1] >> (BITS_PER_TYPE(u32) - shift);
+ }
+}
+
+static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src,
+ const struct nft_bitwise *priv)
+{
+ u32 shift = priv->data.data[0];
+ unsigned int i;
+ u32 carry = 0;
+
+ for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) {
+ dst[i] = carry | (src[i] >> shift);
+ carry = src[i] << (BITS_PER_TYPE(u32) - shift);
+ }
+}
+
+void nft_bitwise_eval(const struct nft_expr *expr,
+ struct nft_regs *regs, const struct nft_pktinfo *pkt)
+{
+ const struct nft_bitwise *priv = nft_expr_priv(expr);
+ const u32 *src = &regs->data[priv->sreg];
+ u32 *dst = &regs->data[priv->dreg];
+
+ switch (priv->op) {
+ case NFT_BITWISE_BOOL:
+ nft_bitwise_eval_bool(dst, src, priv);
+ break;
+ case NFT_BITWISE_LSHIFT:
+ nft_bitwise_eval_lshift(dst, src, priv);
+ break;
+ case NFT_BITWISE_RSHIFT:
+ nft_bitwise_eval_rshift(dst, src, priv);
+ break;
+ }
+}
+
+static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
+ [NFTA_BITWISE_SREG] = { .type = NLA_U32 },
+ [NFTA_BITWISE_DREG] = { .type = NLA_U32 },
+ [NFTA_BITWISE_LEN] = { .type = NLA_U32 },
+ [NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
+ [NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
+ [NFTA_BITWISE_OP] = { .type = NLA_U32 },
+ [NFTA_BITWISE_DATA] = { .type = NLA_NESTED },
+};
+
+static int nft_bitwise_init_bool(struct nft_bitwise *priv,
+ const struct nlattr *const tb[])
+{
+ struct nft_data_desc mask = {
+ .type = NFT_DATA_VALUE,
+ .size = sizeof(priv->mask),
+ .len = priv->len,
+ };
+ struct nft_data_desc xor = {
+ .type = NFT_DATA_VALUE,
+ .size = sizeof(priv->xor),
+ .len = priv->len,
+ };
+ int err;
+
+ if (tb[NFTA_BITWISE_DATA])
+ return -EINVAL;
+
+ if (!tb[NFTA_BITWISE_MASK] ||
+ !tb[NFTA_BITWISE_XOR])
+ return -EINVAL;
+
+ err = nft_data_init(NULL, &priv->mask, &mask, tb[NFTA_BITWISE_MASK]);
+ if (err < 0)
+ return err;
+
+ err = nft_data_init(NULL, &priv->xor, &xor, tb[NFTA_BITWISE_XOR]);
+ if (err < 0)
+ goto err_xor_err;
+
+ return 0;
+
+err_xor_err:
+ nft_data_release(&priv->mask, mask.type);
+
+ return err;
+}
+
+static int nft_bitwise_init_shift(struct nft_bitwise *priv,
+ const struct nlattr *const tb[])
+{
+ struct nft_data_desc desc = {
+ .type = NFT_DATA_VALUE,
+ .size = sizeof(priv->data),
+ .len = sizeof(u32),
+ };
+ int err;
+
+ if (tb[NFTA_BITWISE_MASK] ||
+ tb[NFTA_BITWISE_XOR])
+ return -EINVAL;
+
+ if (!tb[NFTA_BITWISE_DATA])
+ return -EINVAL;
+
+ err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_BITWISE_DATA]);
+ if (err < 0)
+ return err;
+
+ if (priv->data.data[0] >= BITS_PER_TYPE(u32)) {
+ nft_data_release(&priv->data, desc.type);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int nft_bitwise_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_bitwise *priv = nft_expr_priv(expr);
+ u32 len;
+ int err;
+
+ err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
+ if (err < 0)
+ return err;
+
+ priv->len = len;
+
+ err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg,
+ priv->len);
+ if (err < 0)
+ return err;
+
+ err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG],
+ &priv->dreg, NULL, NFT_DATA_VALUE,
+ priv->len);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_BITWISE_OP]) {
+ priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP]));
+ switch (priv->op) {
+ case NFT_BITWISE_BOOL:
+ case NFT_BITWISE_LSHIFT:
+ case NFT_BITWISE_RSHIFT:
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ } else {
+ priv->op = NFT_BITWISE_BOOL;
+ }
+
+ switch(priv->op) {
+ case NFT_BITWISE_BOOL:
+ err = nft_bitwise_init_bool(priv, tb);
+ break;
+ case NFT_BITWISE_LSHIFT:
+ case NFT_BITWISE_RSHIFT:
+ err = nft_bitwise_init_shift(priv, tb);
+ break;
+ }
+
+ return err;
+}
+
+static int nft_bitwise_dump_bool(struct sk_buff *skb,
+ const struct nft_bitwise *priv)
+{
+ if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
+ NFT_DATA_VALUE, priv->len) < 0)
+ return -1;
+
+ if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
+ NFT_DATA_VALUE, priv->len) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int nft_bitwise_dump_shift(struct sk_buff *skb,
+ const struct nft_bitwise *priv)
+{
+ if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data,
+ NFT_DATA_VALUE, sizeof(u32)) < 0)
+ return -1;
+ return 0;
+}
+
+static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_bitwise *priv = nft_expr_priv(expr);
+ int err = 0;
+
+ if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
+ return -1;
+ if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
+ return -1;
+ if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
+ return -1;
+ if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op)))
+ return -1;
+
+ switch (priv->op) {
+ case NFT_BITWISE_BOOL:
+ err = nft_bitwise_dump_bool(skb, priv);
+ break;
+ case NFT_BITWISE_LSHIFT:
+ case NFT_BITWISE_RSHIFT:
+ err = nft_bitwise_dump_shift(skb, priv);
+ break;
+ }
+
+ return err;
+}
+
+static struct nft_data zero;
+
+static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
+ struct nft_flow_rule *flow,
+ const struct nft_expr *expr)
+{
+ const struct nft_bitwise *priv = nft_expr_priv(expr);
+ struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
+
+ if (priv->op != NFT_BITWISE_BOOL)
+ return -EOPNOTSUPP;
+
+ if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
+ priv->sreg != priv->dreg || priv->len != reg->len)
+ return -EOPNOTSUPP;
+
+ memcpy(&reg->mask, &priv->mask, sizeof(priv->mask));
+
+ return 0;
+}
+
+static bool nft_bitwise_reduce(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ const struct nft_bitwise *priv = nft_expr_priv(expr);
+ const struct nft_bitwise *bitwise;
+ unsigned int regcount;
+ u8 dreg;
+ int i;
+
+ if (!track->regs[priv->sreg].selector)
+ return false;
+
+ bitwise = nft_expr_priv(track->regs[priv->dreg].selector);
+ if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
+ track->regs[priv->sreg].num_reg == 0 &&
+ track->regs[priv->dreg].bitwise &&
+ track->regs[priv->dreg].bitwise->ops == expr->ops &&
+ priv->sreg == bitwise->sreg &&
+ priv->dreg == bitwise->dreg &&
+ priv->op == bitwise->op &&
+ priv->len == bitwise->len &&
+ !memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) &&
+ !memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) &&
+ !memcmp(&priv->data, &bitwise->data, sizeof(priv->data))) {
+ track->cur = expr;
+ return true;
+ }
+
+ if (track->regs[priv->sreg].bitwise ||
+ track->regs[priv->sreg].num_reg != 0) {
+ nft_reg_track_cancel(track, priv->dreg, priv->len);
+ return false;
+ }
+
+ if (priv->sreg != priv->dreg) {
+ nft_reg_track_update(track, track->regs[priv->sreg].selector,
+ priv->dreg, priv->len);
+ }
+
+ dreg = priv->dreg;
+ regcount = DIV_ROUND_UP(priv->len, NFT_REG32_SIZE);
+ for (i = 0; i < regcount; i++, dreg++)
+ track->regs[dreg].bitwise = expr;
+
+ return false;
+}
+
+static const struct nft_expr_ops nft_bitwise_ops = {
+ .type = &nft_bitwise_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
+ .eval = nft_bitwise_eval,
+ .init = nft_bitwise_init,
+ .dump = nft_bitwise_dump,
+ .reduce = nft_bitwise_reduce,
+ .offload = nft_bitwise_offload,
+};
+
+static int
+nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out)
+{
+ struct nft_data data;
+ struct nft_data_desc desc = {
+ .type = NFT_DATA_VALUE,
+ .size = sizeof(data),
+ .len = sizeof(u32),
+ };
+ int err;
+
+ err = nft_data_init(NULL, &data, &desc, tb);
+ if (err < 0)
+ return err;
+
+ *out = data.data[0];
+
+ return 0;
+}
+
+static int nft_bitwise_fast_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
+ int err;
+
+ err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg,
+ sizeof(u32));
+ if (err < 0)
+ return err;
+
+ err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg,
+ NULL, NFT_DATA_VALUE, sizeof(u32));
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_BITWISE_DATA])
+ return -EINVAL;
+
+ if (!tb[NFTA_BITWISE_MASK] ||
+ !tb[NFTA_BITWISE_XOR])
+ return -EINVAL;
+
+ err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask);
+ if (err < 0)
+ return err;
+
+ err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static int
+nft_bitwise_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
+ struct nft_data data;
+
+ if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
+ return -1;
+ if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
+ return -1;
+ if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32))))
+ return -1;
+ if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_BOOL)))
+ return -1;
+
+ data.data[0] = priv->mask;
+ if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data,
+ NFT_DATA_VALUE, sizeof(u32)) < 0)
+ return -1;
+
+ data.data[0] = priv->xor;
+ if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data,
+ NFT_DATA_VALUE, sizeof(u32)) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx,
+ struct nft_flow_rule *flow,
+ const struct nft_expr *expr)
+{
+ const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
+ struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
+
+ if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32))
+ return -EOPNOTSUPP;
+
+ reg->mask.data[0] = priv->mask;
+ return 0;
+}
+
+static bool nft_bitwise_fast_reduce(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
+ const struct nft_bitwise_fast_expr *bitwise;
+
+ if (!track->regs[priv->sreg].selector)
+ return false;
+
+ bitwise = nft_expr_priv(track->regs[priv->dreg].selector);
+ if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
+ track->regs[priv->dreg].bitwise &&
+ track->regs[priv->dreg].bitwise->ops == expr->ops &&
+ priv->sreg == bitwise->sreg &&
+ priv->dreg == bitwise->dreg &&
+ priv->mask == bitwise->mask &&
+ priv->xor == bitwise->xor) {
+ track->cur = expr;
+ return true;
+ }
+
+ if (track->regs[priv->sreg].bitwise) {
+ nft_reg_track_cancel(track, priv->dreg, NFT_REG32_SIZE);
+ return false;
+ }
+
+ if (priv->sreg != priv->dreg) {
+ track->regs[priv->dreg].selector =
+ track->regs[priv->sreg].selector;
+ }
+ track->regs[priv->dreg].bitwise = expr;
+
+ return false;
+}
+
+const struct nft_expr_ops nft_bitwise_fast_ops = {
+ .type = &nft_bitwise_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)),
+ .eval = NULL, /* inlined */
+ .init = nft_bitwise_fast_init,
+ .dump = nft_bitwise_fast_dump,
+ .reduce = nft_bitwise_fast_reduce,
+ .offload = nft_bitwise_fast_offload,
+};
+
+static const struct nft_expr_ops *
+nft_bitwise_select_ops(const struct nft_ctx *ctx,
+ const struct nlattr * const tb[])
+{
+ int err;
+ u32 len;
+
+ if (!tb[NFTA_BITWISE_LEN] ||
+ !tb[NFTA_BITWISE_SREG] ||
+ !tb[NFTA_BITWISE_DREG])
+ return ERR_PTR(-EINVAL);
+
+ err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ if (len != sizeof(u32))
+ return &nft_bitwise_ops;
+
+ if (tb[NFTA_BITWISE_OP] &&
+ ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_BOOL)
+ return &nft_bitwise_ops;
+
+ return &nft_bitwise_fast_ops;
+}
+
+struct nft_expr_type nft_bitwise_type __read_mostly = {
+ .name = "bitwise",
+ .select_ops = nft_bitwise_select_ops,
+ .policy = nft_bitwise_policy,
+ .maxattr = NFTA_BITWISE_MAX,
+ .owner = THIS_MODULE,
+};
+
+bool nft_expr_reduce_bitwise(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ const struct nft_expr *last = track->last;
+ const struct nft_expr *next;
+
+ if (expr == last)
+ return false;
+
+ next = nft_expr_next(expr);
+ if (next->ops == &nft_bitwise_ops)
+ return nft_bitwise_reduce(track, next);
+ else if (next->ops == &nft_bitwise_fast_ops)
+ return nft_bitwise_fast_reduce(track, next);
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(nft_expr_reduce_bitwise);
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-25 01:17:15 +0000