diff options
Diffstat (limited to 'net/netfilter/nft_exthdr.c')
| -rw-r--r-- | net/netfilter/nft_exthdr.c | 840 |
1 files changed, 840 insertions, 0 deletions
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c new file mode 100644 index 000000000..de588f7b6 --- /dev/null +++ b/net/netfilter/nft_exthdr.c @@ -0,0 +1,840 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> + * + * Development of this code funded by Astaro AG (http://www.astaro.com/) + */ + +#include <asm/unaligned.h> +#include <linux/kernel.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <linux/dccp.h> +#include <linux/sctp.h> +#include <net/netfilter/nf_tables_core.h> +#include <net/netfilter/nf_tables.h> +#include <net/sctp/sctp.h> +#include <net/tcp.h> + +struct nft_exthdr { + u8 type; + u8 offset; + u8 len; + u8 op; + u8 dreg; + u8 sreg; + u8 flags; +}; + +static unsigned int optlen(const u8 *opt, unsigned int offset) +{ + /* Beware zero-length options: make finite progress */ + if (opt[offset] <= TCPOPT_NOP || opt[offset + 1] == 0) + return 1; + else + return opt[offset + 1]; +} + +static int nft_skb_copy_to_reg(const struct sk_buff *skb, int offset, u32 *dest, unsigned int len) +{ + if (len % NFT_REG32_SIZE) + dest[len / NFT_REG32_SIZE] = 0; + + return skb_copy_bits(skb, offset, dest, len); +} + +static void nft_exthdr_ipv6_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + u32 *dest = ®s->data[priv->dreg]; + unsigned int offset = 0; + int err; + + if (pkt->skb->protocol != htons(ETH_P_IPV6)) + goto err; + + err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL); + if (priv->flags & NFT_EXTHDR_F_PRESENT) { + nft_reg_store8(dest, err >= 0); + return; + } else if (err < 0) { + goto err; + } + offset += priv->offset; + + if (nft_skb_copy_to_reg(pkt->skb, offset, dest, priv->len) < 0) + goto err; + return; +err: + regs->verdict.code = NFT_BREAK; +} + +/* find the offset to specified option. + * + * If target header is found, its offset is set in *offset and return option + * number. Otherwise, return negative error. + * + * If the first fragment doesn't contain the End of Options it is considered + * invalid. + */ +static int ipv4_find_option(struct net *net, struct sk_buff *skb, + unsigned int *offset, int target) +{ + unsigned char optbuf[sizeof(struct ip_options) + 40]; + struct ip_options *opt = (struct ip_options *)optbuf; + struct iphdr *iph, _iph; + unsigned int start; + bool found = false; + __be32 info; + int optlen; + + iph = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (!iph) + return -EBADMSG; + start = sizeof(struct iphdr); + + optlen = iph->ihl * 4 - (int)sizeof(struct iphdr); + if (optlen <= 0) + return -ENOENT; + + memset(opt, 0, sizeof(struct ip_options)); + /* Copy the options since __ip_options_compile() modifies + * the options. + */ + if (skb_copy_bits(skb, start, opt->__data, optlen)) + return -EBADMSG; + opt->optlen = optlen; + + if (__ip_options_compile(net, opt, NULL, &info)) + return -EBADMSG; + + switch (target) { + case IPOPT_SSRR: + case IPOPT_LSRR: + if (!opt->srr) + break; + found = target == IPOPT_SSRR ? opt->is_strictroute : + !opt->is_strictroute; + if (found) + *offset = opt->srr + start; + break; + case IPOPT_RR: + if (!opt->rr) + break; + *offset = opt->rr + start; + found = true; + break; + case IPOPT_RA: + if (!opt->router_alert) + break; + *offset = opt->router_alert + start; + found = true; + break; + default: + return -EOPNOTSUPP; + } + return found ? target : -ENOENT; +} + +static void nft_exthdr_ipv4_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + u32 *dest = ®s->data[priv->dreg]; + struct sk_buff *skb = pkt->skb; + unsigned int offset; + int err; + + if (skb->protocol != htons(ETH_P_IP)) + goto err; + + err = ipv4_find_option(nft_net(pkt), skb, &offset, priv->type); + if (priv->flags & NFT_EXTHDR_F_PRESENT) { + nft_reg_store8(dest, err >= 0); + return; + } else if (err < 0) { + goto err; + } + offset += priv->offset; + + if (nft_skb_copy_to_reg(pkt->skb, offset, dest, priv->len) < 0) + goto err; + return; +err: + 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 != IPPROTO_TCP || pkt->fragoff) + return NULL; + + tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt), 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, nft_thoff(pkt), *tcphdr_len, buffer); +} + +static void nft_exthdr_tcp_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; + u32 *dest = ®s->data[priv->dreg]; + struct tcphdr *tcph; + u8 *opt; + + tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len); + if (!tcph) + goto err; + + opt = (u8 *)tcph; + for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) { + optl = optlen(opt, i); + + if (priv->type != opt[i]) + continue; + + if (i + optl > tcphdr_len || priv->len + priv->offset > optl) + goto err; + + offset = i + priv->offset; + if (priv->flags & NFT_EXTHDR_F_PRESENT) { + nft_reg_store8(dest, 1); + } else { + if (priv->len % NFT_REG32_SIZE) + dest[priv->len / NFT_REG32_SIZE] = 0; + memcpy(dest, opt + offset, priv->len); + } + + return; + } + +err: + if (priv->flags & NFT_EXTHDR_F_PRESENT) + *dest = 0; + else + 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; + + tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len); + if (!tcph) + goto err; + + if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len)) + goto err; + + tcph = (struct tcphdr *)(pkt->skb->data + nft_thoff(pkt)); + opt = (u8 *)tcph; + + for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) { + union { + __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) + goto err; + + offset = i + priv->offset; + + switch (priv->len) { + case 2: + old.v16 = (__force __be16)get_unaligned((u16 *)(opt + offset)); + new.v16 = (__force __be16)nft_reg_load16( + ®s->data[priv->sreg]); + + 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, (__be16*)(opt + offset)); + inet_proto_csum_replace2(&tcph->check, pkt->skb, + old.v16, new.v16, false); + break; + case 4: + new.v32 = nft_reg_load_be32(®s->data[priv->sreg]); + old.v32 = (__force __be32)get_unaligned((u32 *)(opt + offset)); + + if (old.v32 == new.v32) + return; + + put_unaligned(new.v32, (__be32*)(opt + offset)); + inet_proto_csum_replace4(&tcph->check, pkt->skb, + old.v32, new.v32, false); + break; + default: + WARN_ON_ONCE(1); + break; + } + + return; + } + return; +err: + regs->verdict.code = NFT_BREAK; +} + +static void nft_exthdr_tcp_strip_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, tcphdr_len, optl; + struct tcphdr *tcph; + u8 *opt; + + tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len); + if (!tcph) + goto err; + + if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len)) + goto drop; + + tcph = (struct tcphdr *)(pkt->skb->data + nft_thoff(pkt)); + opt = (u8 *)tcph; + + for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) { + unsigned int j; + + optl = optlen(opt, i); + if (priv->type != opt[i]) + continue; + + if (i + optl > tcphdr_len) + goto drop; + + for (j = 0; j < optl; ++j) { + u16 n = TCPOPT_NOP; + u16 o = opt[i+j]; + + if ((i + j) % 2 == 0) { + o <<= 8; + n <<= 8; + } + inet_proto_csum_replace2(&tcph->check, pkt->skb, htons(o), + htons(n), false); + } + memset(opt + i, TCPOPT_NOP, optl); + return; + } + + /* option not found, continue. This allows to do multiple + * option removals per rule. + */ + return; +err: + regs->verdict.code = NFT_BREAK; + return; +drop: + /* can't remove, no choice but to drop */ + regs->verdict.code = NF_DROP; +} + +static void nft_exthdr_sctp_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + unsigned int offset = nft_thoff(pkt) + sizeof(struct sctphdr); + struct nft_exthdr *priv = nft_expr_priv(expr); + u32 *dest = ®s->data[priv->dreg]; + const struct sctp_chunkhdr *sch; + struct sctp_chunkhdr _sch; + + if (pkt->tprot != IPPROTO_SCTP) + goto err; + + do { + sch = skb_header_pointer(pkt->skb, offset, sizeof(_sch), &_sch); + if (!sch || !sch->length) + break; + + if (sch->type == priv->type) { + if (priv->flags & NFT_EXTHDR_F_PRESENT) { + nft_reg_store8(dest, true); + return; + } + if (priv->offset + priv->len > ntohs(sch->length) || + offset + ntohs(sch->length) > pkt->skb->len) + break; + + if (nft_skb_copy_to_reg(pkt->skb, offset + priv->offset, + dest, priv->len) < 0) + break; + return; + } + offset += SCTP_PAD4(ntohs(sch->length)); + } while (offset < pkt->skb->len); +err: + if (priv->flags & NFT_EXTHDR_F_PRESENT) + nft_reg_store8(dest, false); + else + regs->verdict.code = NFT_BREAK; +} + +static void nft_exthdr_dccp_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + unsigned int thoff, dataoff, optoff, optlen, i; + u32 *dest = ®s->data[priv->dreg]; + const struct dccp_hdr *dh; + struct dccp_hdr _dh; + + if (pkt->tprot != IPPROTO_DCCP || pkt->fragoff) + goto err; + + thoff = nft_thoff(pkt); + + dh = skb_header_pointer(pkt->skb, thoff, sizeof(_dh), &_dh); + if (!dh) + goto err; + + dataoff = dh->dccph_doff * sizeof(u32); + optoff = __dccp_hdr_len(dh); + if (dataoff <= optoff) + goto err; + + optlen = dataoff - optoff; + + for (i = 0; i < optlen; ) { + /* Options 0 (DCCPO_PADDING) - 31 (DCCPO_MAX_RESERVED) are 1B in + * the length; the remaining options are at least 2B long. In + * all cases, the first byte contains the option type. In + * multi-byte options, the second byte contains the option + * length, which must be at least two: 1 for the type plus 1 for + * the length plus 0-253 for any following option data. We + * aren't interested in the option data, only the type and the + * length, so we don't need to read more than two bytes at a + * time. + */ + unsigned int buflen = optlen - i; + u8 buf[2], *bufp; + u8 type, len; + + if (buflen > sizeof(buf)) + buflen = sizeof(buf); + + bufp = skb_header_pointer(pkt->skb, thoff + optoff + i, buflen, + &buf); + if (!bufp) + goto err; + + type = bufp[0]; + + if (type == priv->type) { + nft_reg_store8(dest, 1); + return; + } + + if (type <= DCCPO_MAX_RESERVED) { + i++; + continue; + } + + if (buflen < 2) + goto err; + + len = bufp[1]; + + if (len < 2) + goto err; + + i += len; + } + +err: + *dest = 0; +} + +static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = { + [NFTA_EXTHDR_DREG] = { .type = NLA_U32 }, + [NFTA_EXTHDR_TYPE] = { .type = NLA_U8 }, + [NFTA_EXTHDR_OFFSET] = { .type = NLA_U32 }, + [NFTA_EXTHDR_LEN] = { .type = NLA_U32 }, + [NFTA_EXTHDR_FLAGS] = { .type = NLA_U32 }, + [NFTA_EXTHDR_OP] = { .type = NLA_U32 }, + [NFTA_EXTHDR_SREG] = { .type = NLA_U32 }, +}; + +static int nft_exthdr_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + u32 offset, len, flags = 0, op = NFT_EXTHDR_OP_IPV6; + int err; + + if (!tb[NFTA_EXTHDR_DREG] || + !tb[NFTA_EXTHDR_TYPE] || + !tb[NFTA_EXTHDR_OFFSET] || + !tb[NFTA_EXTHDR_LEN]) + 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 (tb[NFTA_EXTHDR_FLAGS]) { + err = nft_parse_u32_check(tb[NFTA_EXTHDR_FLAGS], U8_MAX, &flags); + if (err < 0) + return err; + + if (flags & ~NFT_EXTHDR_F_PRESENT) + return -EINVAL; + } + + if (tb[NFTA_EXTHDR_OP]) { + 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->flags = flags; + priv->op = op; + + return nft_parse_register_store(ctx, tb[NFTA_EXTHDR_DREG], + &priv->dreg, NULL, NFT_DATA_VALUE, + priv->len); +} + +static int nft_exthdr_tcp_set_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + u32 offset, len, flags = 0, op = NFT_EXTHDR_OP_IPV6; + int err; + + 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->flags = flags; + priv->op = op; + + return nft_parse_register_load(tb[NFTA_EXTHDR_SREG], &priv->sreg, + priv->len); +} + +static int nft_exthdr_tcp_strip_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + + if (tb[NFTA_EXTHDR_SREG] || + tb[NFTA_EXTHDR_DREG] || + tb[NFTA_EXTHDR_FLAGS] || + tb[NFTA_EXTHDR_OFFSET] || + tb[NFTA_EXTHDR_LEN]) + return -EINVAL; + + if (!tb[NFTA_EXTHDR_TYPE]) + return -EINVAL; + + priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]); + priv->op = NFT_EXTHDR_OP_TCPOPT; + + return 0; +} + +static int nft_exthdr_ipv4_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + int err = nft_exthdr_init(ctx, expr, tb); + + if (err < 0) + return err; + + switch (priv->type) { + case IPOPT_SSRR: + case IPOPT_LSRR: + case IPOPT_RR: + case IPOPT_RA: + break; + default: + return -EOPNOTSUPP; + } + return 0; +} + +static int nft_exthdr_dccp_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_exthdr *priv = nft_expr_priv(expr); + int err = nft_exthdr_init(ctx, expr, tb); + + if (err < 0) + return err; + + if (!(priv->flags & NFT_EXTHDR_F_PRESENT)) + return -EOPNOTSUPP; + + return 0; +} + +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))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_EXTHDR_FLAGS, htonl(priv->flags))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_EXTHDR_OP, htonl(priv->op))) + goto nla_put_failure; + return 0; + +nla_put_failure: + 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 int nft_exthdr_dump_strip(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_exthdr *priv = nft_expr_priv(expr); + + return nft_exthdr_dump_common(skb, priv); +} + +static bool nft_exthdr_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_exthdr *priv = nft_expr_priv(expr); + const struct nft_exthdr *exthdr; + + if (!nft_reg_track_cmp(track, expr, priv->dreg)) { + nft_reg_track_update(track, expr, priv->dreg, priv->len); + return false; + } + + exthdr = nft_expr_priv(track->regs[priv->dreg].selector); + if (priv->type != exthdr->type || + priv->op != exthdr->op || + priv->flags != exthdr->flags || + priv->offset != exthdr->offset || + priv->len != exthdr->len) { + nft_reg_track_update(track, expr, priv->dreg, priv->len); + return false; + } + + if (!track->regs[priv->dreg].bitwise) + return true; + + return nft_expr_reduce_bitwise(track, expr); +} + +static const struct nft_expr_ops nft_exthdr_ipv6_ops = { + .type = &nft_exthdr_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), + .eval = nft_exthdr_ipv6_eval, + .init = nft_exthdr_init, + .dump = nft_exthdr_dump, + .reduce = nft_exthdr_reduce, +}; + +static const struct nft_expr_ops nft_exthdr_ipv4_ops = { + .type = &nft_exthdr_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), + .eval = nft_exthdr_ipv4_eval, + .init = nft_exthdr_ipv4_init, + .dump = nft_exthdr_dump, + .reduce = nft_exthdr_reduce, +}; + +static const struct nft_expr_ops nft_exthdr_tcp_ops = { + .type = &nft_exthdr_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), + .eval = nft_exthdr_tcp_eval, + .init = nft_exthdr_init, + .dump = nft_exthdr_dump, + .reduce = nft_exthdr_reduce, +}; + +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, + .reduce = NFT_REDUCE_READONLY, +}; + +static const struct nft_expr_ops nft_exthdr_tcp_strip_ops = { + .type = &nft_exthdr_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), + .eval = nft_exthdr_tcp_strip_eval, + .init = nft_exthdr_tcp_strip_init, + .dump = nft_exthdr_dump_strip, + .reduce = NFT_REDUCE_READONLY, +}; + +static const struct nft_expr_ops nft_exthdr_sctp_ops = { + .type = &nft_exthdr_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), + .eval = nft_exthdr_sctp_eval, + .init = nft_exthdr_init, + .dump = nft_exthdr_dump, + .reduce = nft_exthdr_reduce, +}; + +static const struct nft_expr_ops nft_exthdr_dccp_ops = { + .type = &nft_exthdr_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), + .eval = nft_exthdr_dccp_eval, + .init = nft_exthdr_dccp_init, + .dump = nft_exthdr_dump, + .reduce = nft_exthdr_reduce, +}; + +static const struct nft_expr_ops * +nft_exthdr_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + u32 op; + + if (!tb[NFTA_EXTHDR_OP]) + return &nft_exthdr_ipv6_ops; + + 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: + if (tb[NFTA_EXTHDR_SREG]) + return &nft_exthdr_tcp_set_ops; + if (tb[NFTA_EXTHDR_DREG]) + return &nft_exthdr_tcp_ops; + return &nft_exthdr_tcp_strip_ops; + case NFT_EXTHDR_OP_IPV6: + if (tb[NFTA_EXTHDR_DREG]) + return &nft_exthdr_ipv6_ops; + break; + case NFT_EXTHDR_OP_IPV4: + if (ctx->family != NFPROTO_IPV6) { + if (tb[NFTA_EXTHDR_DREG]) + return &nft_exthdr_ipv4_ops; + } + break; + case NFT_EXTHDR_OP_SCTP: + if (tb[NFTA_EXTHDR_DREG]) + return &nft_exthdr_sctp_ops; + break; + case NFT_EXTHDR_OP_DCCP: + if (tb[NFTA_EXTHDR_DREG]) + return &nft_exthdr_dccp_ops; + break; + } + + return ERR_PTR(-EOPNOTSUPP); +} + +struct nft_expr_type nft_exthdr_type __read_mostly = { + .name = "exthdr", + .select_ops = nft_exthdr_select_ops, + .policy = nft_exthdr_policy, + .maxattr = NFTA_EXTHDR_MAX, + .owner = THIS_MODULE, +}; 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