cregit-Linux how code gets into the kernel

Release 4.14 net/netfilter/nft_rt.c

Directory: net/netfilter
/*
 * Copyright (c) 2016 Anders K. Pedersen <akp@cohaesio.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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/dst.h>
#include <net/ip6_route.h>
#include <net/route.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>


struct nft_rt {
	
enum nft_rt_keys	key:8;
	
enum nft_registers	dreg:8;
};


static u16 get_tcpmss(const struct nft_pktinfo *pkt, const struct dst_entry *skbdst) { u32 minlen = sizeof(struct ipv6hdr), mtu = dst_mtu(skbdst); const struct sk_buff *skb = pkt->skb; const struct nf_afinfo *ai; struct flowi fl; memset(&fl, 0, sizeof(fl)); switch (nft_pf(pkt)) { case NFPROTO_IPV4: fl.u.ip4.daddr = ip_hdr(skb)->saddr; minlen = sizeof(struct iphdr) + sizeof(struct tcphdr); break; case NFPROTO_IPV6: fl.u.ip6.daddr = ipv6_hdr(skb)->saddr; minlen = sizeof(struct ipv6hdr) + sizeof(struct tcphdr); break; } ai = nf_get_afinfo(nft_pf(pkt)); if (ai) { struct dst_entry *dst = NULL; ai->route(nft_net(pkt), &dst, &fl, false); if (dst) { mtu = min(mtu, dst_mtu(dst)); dst_release(dst); } } if (mtu <= minlen || mtu > 0xffff) return TCP_MSS_DEFAULT; return mtu - minlen; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Westphal224100.00%2100.00%
Total224100.00%2100.00%


static void nft_rt_get_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { const struct nft_rt *priv = nft_expr_priv(expr); const struct sk_buff *skb = pkt->skb; u32 *dest = &regs->data[priv->dreg]; const struct dst_entry *dst; dst = skb_dst(skb); if (!dst) goto err; switch (priv->key) { #ifdef CONFIG_IP_ROUTE_CLASSID case NFT_RT_CLASSID: *dest = dst->tclassid; break; #endif case NFT_RT_NEXTHOP4: if (nft_pf(pkt) != NFPROTO_IPV4) goto err; *dest = (__force u32)rt_nexthop((const struct rtable *)dst, ip_hdr(skb)->daddr); break; case NFT_RT_NEXTHOP6: if (nft_pf(pkt) != NFPROTO_IPV6) goto err; memcpy(dest, rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr), sizeof(struct in6_addr)); break; case NFT_RT_TCPMSS: nft_reg_store16(dest, get_tcpmss(pkt, dst)); break; default: WARN_ON(1); goto err; } return; err: regs->verdict.code = NFT_BREAK; }

Contributors

PersonTokensPropCommitsCommitProp
Anders K. Pedersen19888.00%120.00%
Florian Westphal208.89%240.00%
Pablo Neira Ayuso62.67%120.00%
Stephen Hemminger10.44%120.00%
Total225100.00%5100.00%

static const struct nla_policy nft_rt_policy[NFTA_RT_MAX + 1] = { [NFTA_RT_DREG] = { .type = NLA_U32 }, [NFTA_RT_KEY] = { .type = NLA_U32 }, };
static int nft_rt_get_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) { struct nft_rt *priv = nft_expr_priv(expr); unsigned int len; if (tb[NFTA_RT_KEY] == NULL || tb[NFTA_RT_DREG] == NULL) return -EINVAL; priv->key = ntohl(nla_get_be32(tb[NFTA_RT_KEY])); switch (priv->key) { #ifdef CONFIG_IP_ROUTE_CLASSID case NFT_RT_CLASSID: #endif case NFT_RT_NEXTHOP4: len = sizeof(u32); break; case NFT_RT_NEXTHOP6: len = sizeof(struct in6_addr); break; case NFT_RT_TCPMSS: len = sizeof(u16); break; default: return -EOPNOTSUPP; } priv->dreg = nft_parse_register(tb[NFTA_RT_DREG]); return nft_validate_register_store(ctx, priv->dreg, NULL, NFT_DATA_VALUE, len); }

Contributors

PersonTokensPropCommitsCommitProp
Anders K. Pedersen14692.41%133.33%
Florian Westphal116.96%133.33%
Stephen Hemminger10.63%133.33%
Total158100.00%3100.00%


static int nft_rt_get_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_rt *priv = nft_expr_priv(expr); if (nla_put_be32(skb, NFTA_RT_KEY, htonl(priv->key))) goto nla_put_failure; if (nft_dump_register(skb, NFTA_RT_DREG, priv->dreg)) goto nla_put_failure; return 0; nla_put_failure: return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Anders K. Pedersen7198.61%150.00%
Stephen Hemminger11.39%150.00%
Total72100.00%2100.00%


static int nft_rt_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nft_data **data) { const struct nft_rt *priv = nft_expr_priv(expr); unsigned int hooks; switch (priv->key) { case NFT_RT_NEXTHOP4: case NFT_RT_NEXTHOP6: case NFT_RT_CLASSID: return 0; case NFT_RT_TCPMSS: hooks = (1 << NF_INET_FORWARD) | (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_POST_ROUTING); break; default: return -EINVAL; } return nft_chain_validate_hooks(ctx->chain, hooks); }

Contributors

PersonTokensPropCommitsCommitProp
Florian Westphal99100.00%1100.00%
Total99100.00%1100.00%

static struct nft_expr_type nft_rt_type; static const struct nft_expr_ops nft_rt_get_ops = { .type = &nft_rt_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_rt)), .eval = nft_rt_get_eval, .init = nft_rt_get_init, .dump = nft_rt_get_dump, .validate = nft_rt_validate, }; static struct nft_expr_type nft_rt_type __read_mostly = { .name = "rt", .ops = &nft_rt_get_ops, .policy = nft_rt_policy, .maxattr = NFTA_RT_MAX, .owner = THIS_MODULE, };
static int __init nft_rt_module_init(void) { return nft_register_expr(&nft_rt_type); }

Contributors

PersonTokensPropCommitsCommitProp
Anders K. Pedersen16100.00%1100.00%
Total16100.00%1100.00%


static void __exit nft_rt_module_exit(void) { nft_unregister_expr(&nft_rt_type); }

Contributors

PersonTokensPropCommitsCommitProp
Anders K. Pedersen15100.00%1100.00%
Total15100.00%1100.00%

module_init(nft_rt_module_init); module_exit(nft_rt_module_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Anders K. Pedersen <akp@cohaesio.com>"); MODULE_ALIAS_NFT_EXPR("rt");

Overall Contributors

PersonTokensPropCommitsCommitProp
Anders K. Pedersen63663.28%116.67%
Florian Westphal36035.82%350.00%
Pablo Neira Ayuso60.60%116.67%
Stephen Hemminger30.30%116.67%
Total1005100.00%6100.00%
Directory: net/netfilter
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