* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
+#include <asm/unaligned.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
u8 len;
u8 op;
enum nft_registers dreg:8;
+ enum nft_registers sreg:8;
u8 flags;
};
regs->verdict.code = NFT_BREAK;
}
+static void *
+nft_tcp_header_pointer(const struct nft_pktinfo *pkt,
+ unsigned int len, void *buffer, unsigned int *tcphdr_len)
+{
+ struct tcphdr *tcph;
+
+ if (!pkt->tprot_set || pkt->tprot != IPPROTO_TCP)
+ return NULL;
+
+ tcph = skb_header_pointer(pkt->skb, pkt->xt.thoff, sizeof(*tcph), buffer);
+ if (!tcph)
+ return NULL;
+
+ *tcphdr_len = __tcp_hdrlen(tcph);
+ if (*tcphdr_len < sizeof(*tcph) || *tcphdr_len > len)
+ return NULL;
+
+ return skb_header_pointer(pkt->skb, pkt->xt.thoff, *tcphdr_len, buffer);
+}
+
static void nft_exthdr_tcp_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
struct tcphdr *tcph;
u8 *opt;
- if (!pkt->tprot_set || pkt->tprot != IPPROTO_TCP)
- goto err;
-
- tcph = skb_header_pointer(pkt->skb, pkt->xt.thoff, sizeof(*tcph), buff);
- if (!tcph)
- goto err;
-
- tcphdr_len = __tcp_hdrlen(tcph);
- if (tcphdr_len < sizeof(*tcph))
- goto err;
-
- tcph = skb_header_pointer(pkt->skb, pkt->xt.thoff, tcphdr_len, buff);
+ tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
if (!tcph)
goto err;
regs->verdict.code = NFT_BREAK;
}
+static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ u8 buff[sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE];
+ struct nft_exthdr *priv = nft_expr_priv(expr);
+ unsigned int i, optl, tcphdr_len, offset;
+ struct tcphdr *tcph;
+ u8 *opt;
+ u32 src;
+
+ tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
+ if (!tcph)
+ return;
+
+ opt = (u8 *)tcph;
+ for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
+ union {
+ u8 octet;
+ __be16 v16;
+ __be32 v32;
+ } old, new;
+
+ optl = optlen(opt, i);
+
+ if (priv->type != opt[i])
+ continue;
+
+ if (i + optl > tcphdr_len || priv->len + priv->offset > optl)
+ return;
+
+ if (!skb_make_writable(pkt->skb, pkt->xt.thoff + i + priv->len))
+ return;
+
+ tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff,
+ &tcphdr_len);
+ if (!tcph)
+ return;
+
+ src = regs->data[priv->sreg];
+ offset = i + priv->offset;
+
+ switch (priv->len) {
+ case 2:
+ old.v16 = get_unaligned((u16 *)(opt + offset));
+ new.v16 = src;
+
+ switch (priv->type) {
+ case TCPOPT_MSS:
+ /* increase can cause connection to stall */
+ if (ntohs(old.v16) <= ntohs(new.v16))
+ return;
+ break;
+ }
+
+ if (old.v16 == new.v16)
+ return;
+
+ put_unaligned(new.v16, (u16*)(opt + offset));
+ inet_proto_csum_replace2(&tcph->check, pkt->skb,
+ old.v16, new.v16, false);
+ break;
+ case 4:
+ new.v32 = src;
+ old.v32 = get_unaligned((u32 *)(opt + offset));
+
+ if (old.v32 == new.v32)
+ return;
+
+ put_unaligned(new.v32, (u32*)(opt + offset));
+ inet_proto_csum_replace4(&tcph->check, pkt->skb,
+ old.v32, new.v32, false);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+
+ return;
+ }
+}
+
static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
[NFTA_EXTHDR_DREG] = { .type = NLA_U32 },
[NFTA_EXTHDR_TYPE] = { .type = NLA_U8 },
NFT_DATA_VALUE, priv->len);
}
-static int nft_exthdr_dump(struct sk_buff *skb, const struct nft_expr *expr)
+static int nft_exthdr_tcp_set_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
{
- const struct nft_exthdr *priv = nft_expr_priv(expr);
+ struct nft_exthdr *priv = nft_expr_priv(expr);
+ u32 offset, len, flags = 0, op = NFT_EXTHDR_OP_IPV6;
+ int err;
- if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
- goto nla_put_failure;
+ if (!tb[NFTA_EXTHDR_SREG] ||
+ !tb[NFTA_EXTHDR_TYPE] ||
+ !tb[NFTA_EXTHDR_OFFSET] ||
+ !tb[NFTA_EXTHDR_LEN])
+ return -EINVAL;
+
+ if (tb[NFTA_EXTHDR_DREG] || tb[NFTA_EXTHDR_FLAGS])
+ return -EINVAL;
+
+ err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
+ if (err < 0)
+ return err;
+
+ err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
+ if (err < 0)
+ return err;
+
+ if (offset < 2)
+ return -EOPNOTSUPP;
+
+ switch (len) {
+ case 2: break;
+ case 4: break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ err = nft_parse_u32_check(tb[NFTA_EXTHDR_OP], U8_MAX, &op);
+ if (err < 0)
+ return err;
+
+ priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
+ priv->offset = offset;
+ priv->len = len;
+ priv->sreg = nft_parse_register(tb[NFTA_EXTHDR_SREG]);
+ priv->flags = flags;
+ priv->op = op;
+
+ return nft_validate_register_load(priv->sreg, priv->len);
+}
+
+static int nft_exthdr_dump_common(struct sk_buff *skb, const struct nft_exthdr *priv)
+{
if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
return -1;
}
+static int nft_exthdr_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_exthdr *priv = nft_expr_priv(expr);
+
+ if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
+ return -1;
+
+ return nft_exthdr_dump_common(skb, priv);
+}
+
+static int nft_exthdr_dump_set(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_exthdr *priv = nft_expr_priv(expr);
+
+ if (nft_dump_register(skb, NFTA_EXTHDR_SREG, priv->sreg))
+ return -1;
+
+ return nft_exthdr_dump_common(skb, priv);
+}
+
static struct nft_expr_type nft_exthdr_type;
static const struct nft_expr_ops nft_exthdr_ipv6_ops = {
.type = &nft_exthdr_type,
.dump = nft_exthdr_dump,
};
+static const struct nft_expr_ops nft_exthdr_tcp_set_ops = {
+ .type = &nft_exthdr_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
+ .eval = nft_exthdr_tcp_set_eval,
+ .init = nft_exthdr_tcp_set_init,
+ .dump = nft_exthdr_dump_set,
+};
+
static const struct nft_expr_ops *
nft_exthdr_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
if (!tb[NFTA_EXTHDR_OP])
return &nft_exthdr_ipv6_ops;
- op = ntohl(nla_get_u32(tb[NFTA_EXTHDR_OP]));
+ if (tb[NFTA_EXTHDR_SREG] && tb[NFTA_EXTHDR_DREG])
+ return ERR_PTR(-EOPNOTSUPP);
+
+ op = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OP]));
switch (op) {
case NFT_EXTHDR_OP_TCPOPT:
- return &nft_exthdr_tcp_ops;
+ if (tb[NFTA_EXTHDR_SREG])
+ return &nft_exthdr_tcp_set_ops;
+ if (tb[NFTA_EXTHDR_DREG])
+ return &nft_exthdr_tcp_ops;
+ break;
case NFT_EXTHDR_OP_IPV6:
- return &nft_exthdr_ipv6_ops;
+ if (tb[NFTA_EXTHDR_DREG])
+ return &nft_exthdr_ipv6_ops;
+ break;
}
return ERR_PTR(-EOPNOTSUPP);
projects / mirror_ubuntu-bionic-kernel.git / blobdiff