![Jamal Hadi Salim](/assets/img/avatar_default.png)
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
624 lines
14 KiB
C
624 lines
14 KiB
C
/*
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* Checksum updating actions
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*
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* Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/netlink.h>
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#include <net/netlink.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <net/icmp.h>
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#include <linux/icmpv6.h>
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#include <linux/igmp.h>
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#include <net/tcp.h>
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#include <net/udp.h>
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#include <net/ip6_checksum.h>
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#include <net/act_api.h>
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#include <linux/tc_act/tc_csum.h>
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#include <net/tc_act/tc_csum.h>
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#define CSUM_TAB_MASK 15
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static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
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[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
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};
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static int csum_net_id;
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static int tcf_csum_init(struct net *net, struct nlattr *nla,
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struct nlattr *est, struct tc_action *a, int ovr,
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int bind)
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{
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struct tc_action_net *tn = net_generic(net, csum_net_id);
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struct nlattr *tb[TCA_CSUM_MAX + 1];
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struct tc_csum *parm;
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struct tcf_csum *p;
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int ret = 0, err;
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if (nla == NULL)
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return -EINVAL;
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err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy);
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if (err < 0)
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return err;
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if (tb[TCA_CSUM_PARMS] == NULL)
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return -EINVAL;
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parm = nla_data(tb[TCA_CSUM_PARMS]);
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if (!tcf_hash_check(tn, parm->index, a, bind)) {
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ret = tcf_hash_create(tn, parm->index, est, a,
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sizeof(*p), bind, false);
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if (ret)
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return ret;
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ret = ACT_P_CREATED;
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} else {
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if (bind)/* dont override defaults */
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return 0;
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tcf_hash_release(a, bind);
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if (!ovr)
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return -EEXIST;
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}
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p = to_tcf_csum(a);
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spin_lock_bh(&p->tcf_lock);
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p->tcf_action = parm->action;
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p->update_flags = parm->update_flags;
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spin_unlock_bh(&p->tcf_lock);
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if (ret == ACT_P_CREATED)
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tcf_hash_insert(tn, a);
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return ret;
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}
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/**
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* tcf_csum_skb_nextlayer - Get next layer pointer
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* @skb: sk_buff to use
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* @ihl: previous summed headers length
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* @ipl: complete packet length
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* @jhl: next header length
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*
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* Check the expected next layer availability in the specified sk_buff.
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* Return the next layer pointer if pass, NULL otherwise.
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*/
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static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl,
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unsigned int jhl)
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{
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int ntkoff = skb_network_offset(skb);
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int hl = ihl + jhl;
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if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
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skb_try_make_writable(skb, hl + ntkoff))
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return NULL;
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else
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return (void *)(skb_network_header(skb) + ihl);
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}
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static int tcf_csum_ipv4_icmp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl)
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{
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struct icmphdr *icmph;
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icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
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if (icmph == NULL)
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return 0;
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icmph->checksum = 0;
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skb->csum = csum_partial(icmph, ipl - ihl, 0);
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icmph->checksum = csum_fold(skb->csum);
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skb->ip_summed = CHECKSUM_NONE;
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return 1;
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}
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static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl)
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{
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struct igmphdr *igmph;
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igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
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if (igmph == NULL)
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return 0;
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igmph->csum = 0;
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skb->csum = csum_partial(igmph, ipl - ihl, 0);
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igmph->csum = csum_fold(skb->csum);
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skb->ip_summed = CHECKSUM_NONE;
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return 1;
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}
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static int tcf_csum_ipv6_icmp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl)
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{
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struct icmp6hdr *icmp6h;
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const struct ipv6hdr *ip6h;
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icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
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if (icmp6h == NULL)
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return 0;
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ip6h = ipv6_hdr(skb);
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icmp6h->icmp6_cksum = 0;
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skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
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icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
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ipl - ihl, IPPROTO_ICMPV6,
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skb->csum);
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skb->ip_summed = CHECKSUM_NONE;
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return 1;
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}
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static int tcf_csum_ipv4_tcp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl)
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{
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struct tcphdr *tcph;
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const struct iphdr *iph;
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tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
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if (tcph == NULL)
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return 0;
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iph = ip_hdr(skb);
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tcph->check = 0;
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skb->csum = csum_partial(tcph, ipl - ihl, 0);
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tcph->check = tcp_v4_check(ipl - ihl,
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iph->saddr, iph->daddr, skb->csum);
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skb->ip_summed = CHECKSUM_NONE;
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return 1;
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}
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static int tcf_csum_ipv6_tcp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl)
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{
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struct tcphdr *tcph;
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const struct ipv6hdr *ip6h;
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tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
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if (tcph == NULL)
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return 0;
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ip6h = ipv6_hdr(skb);
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tcph->check = 0;
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skb->csum = csum_partial(tcph, ipl - ihl, 0);
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tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
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ipl - ihl, IPPROTO_TCP,
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skb->csum);
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skb->ip_summed = CHECKSUM_NONE;
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return 1;
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}
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static int tcf_csum_ipv4_udp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl, int udplite)
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{
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struct udphdr *udph;
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const struct iphdr *iph;
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u16 ul;
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/*
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* Support both UDP and UDPLITE checksum algorithms, Don't use
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* udph->len to get the real length without any protocol check,
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* UDPLITE uses udph->len for another thing,
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* Use iph->tot_len, or just ipl.
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*/
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udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
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if (udph == NULL)
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return 0;
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iph = ip_hdr(skb);
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ul = ntohs(udph->len);
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if (udplite || udph->check) {
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udph->check = 0;
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if (udplite) {
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if (ul == 0)
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skb->csum = csum_partial(udph, ipl - ihl, 0);
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else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
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skb->csum = csum_partial(udph, ul, 0);
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else
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goto ignore_obscure_skb;
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} else {
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if (ul != ipl - ihl)
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goto ignore_obscure_skb;
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skb->csum = csum_partial(udph, ul, 0);
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}
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udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
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ul, iph->protocol,
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skb->csum);
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if (!udph->check)
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udph->check = CSUM_MANGLED_0;
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}
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skb->ip_summed = CHECKSUM_NONE;
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ignore_obscure_skb:
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return 1;
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}
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static int tcf_csum_ipv6_udp(struct sk_buff *skb,
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unsigned int ihl, unsigned int ipl, int udplite)
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{
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struct udphdr *udph;
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const struct ipv6hdr *ip6h;
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u16 ul;
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/*
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* Support both UDP and UDPLITE checksum algorithms, Don't use
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* udph->len to get the real length without any protocol check,
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* UDPLITE uses udph->len for another thing,
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* Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
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*/
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udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
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if (udph == NULL)
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return 0;
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ip6h = ipv6_hdr(skb);
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ul = ntohs(udph->len);
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udph->check = 0;
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if (udplite) {
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if (ul == 0)
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skb->csum = csum_partial(udph, ipl - ihl, 0);
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else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
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skb->csum = csum_partial(udph, ul, 0);
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else
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goto ignore_obscure_skb;
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} else {
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if (ul != ipl - ihl)
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goto ignore_obscure_skb;
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skb->csum = csum_partial(udph, ul, 0);
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}
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udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
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udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
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skb->csum);
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if (!udph->check)
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udph->check = CSUM_MANGLED_0;
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skb->ip_summed = CHECKSUM_NONE;
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ignore_obscure_skb:
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return 1;
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}
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static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
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{
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const struct iphdr *iph;
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int ntkoff;
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ntkoff = skb_network_offset(skb);
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if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
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goto fail;
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iph = ip_hdr(skb);
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switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
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case IPPROTO_ICMP:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
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if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
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ntohs(iph->tot_len)))
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goto fail;
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break;
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case IPPROTO_IGMP:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
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if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
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ntohs(iph->tot_len)))
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goto fail;
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break;
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case IPPROTO_TCP:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
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if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
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ntohs(iph->tot_len)))
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goto fail;
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break;
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case IPPROTO_UDP:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
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if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
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ntohs(iph->tot_len), 0))
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goto fail;
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break;
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case IPPROTO_UDPLITE:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
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if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
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ntohs(iph->tot_len), 1))
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goto fail;
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break;
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}
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if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
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if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
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goto fail;
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ip_send_check(ip_hdr(skb));
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}
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return 1;
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fail:
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return 0;
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}
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static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh,
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unsigned int ixhl, unsigned int *pl)
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{
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int off, len, optlen;
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unsigned char *xh = (void *)ip6xh;
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off = sizeof(*ip6xh);
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len = ixhl - off;
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while (len > 1) {
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switch (xh[off]) {
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case IPV6_TLV_PAD1:
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optlen = 1;
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break;
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case IPV6_TLV_JUMBO:
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optlen = xh[off + 1] + 2;
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if (optlen != 6 || len < 6 || (off & 3) != 2)
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/* wrong jumbo option length/alignment */
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return 0;
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*pl = ntohl(*(__be32 *)(xh + off + 2));
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goto done;
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default:
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optlen = xh[off + 1] + 2;
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if (optlen > len)
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/* ignore obscure options */
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goto done;
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break;
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}
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off += optlen;
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len -= optlen;
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}
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done:
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return 1;
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}
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static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
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{
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struct ipv6hdr *ip6h;
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struct ipv6_opt_hdr *ip6xh;
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unsigned int hl, ixhl;
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unsigned int pl;
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int ntkoff;
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u8 nexthdr;
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ntkoff = skb_network_offset(skb);
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hl = sizeof(*ip6h);
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if (!pskb_may_pull(skb, hl + ntkoff))
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goto fail;
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ip6h = ipv6_hdr(skb);
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pl = ntohs(ip6h->payload_len);
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nexthdr = ip6h->nexthdr;
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do {
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switch (nexthdr) {
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case NEXTHDR_FRAGMENT:
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goto ignore_skb;
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case NEXTHDR_ROUTING:
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case NEXTHDR_HOP:
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case NEXTHDR_DEST:
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if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
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goto fail;
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ip6xh = (void *)(skb_network_header(skb) + hl);
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ixhl = ipv6_optlen(ip6xh);
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if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
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goto fail;
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ip6xh = (void *)(skb_network_header(skb) + hl);
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if ((nexthdr == NEXTHDR_HOP) &&
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!(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
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goto fail;
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nexthdr = ip6xh->nexthdr;
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hl += ixhl;
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break;
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case IPPROTO_ICMPV6:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
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if (!tcf_csum_ipv6_icmp(skb,
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hl, pl + sizeof(*ip6h)))
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goto fail;
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goto done;
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case IPPROTO_TCP:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
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if (!tcf_csum_ipv6_tcp(skb,
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hl, pl + sizeof(*ip6h)))
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goto fail;
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goto done;
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case IPPROTO_UDP:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
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if (!tcf_csum_ipv6_udp(skb, hl,
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pl + sizeof(*ip6h), 0))
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goto fail;
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goto done;
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case IPPROTO_UDPLITE:
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if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
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if (!tcf_csum_ipv6_udp(skb, hl,
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pl + sizeof(*ip6h), 1))
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goto fail;
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goto done;
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default:
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goto ignore_skb;
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}
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} while (pskb_may_pull(skb, hl + 1 + ntkoff));
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done:
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ignore_skb:
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return 1;
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fail:
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return 0;
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}
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static int tcf_csum(struct sk_buff *skb,
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const struct tc_action *a, struct tcf_result *res)
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{
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struct tcf_csum *p = a->priv;
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int action;
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u32 update_flags;
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spin_lock(&p->tcf_lock);
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tcf_lastuse_update(&p->tcf_tm);
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bstats_update(&p->tcf_bstats, skb);
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action = p->tcf_action;
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update_flags = p->update_flags;
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spin_unlock(&p->tcf_lock);
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if (unlikely(action == TC_ACT_SHOT))
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goto drop;
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|
|
|
switch (tc_skb_protocol(skb)) {
|
|
case cpu_to_be16(ETH_P_IP):
|
|
if (!tcf_csum_ipv4(skb, update_flags))
|
|
goto drop;
|
|
break;
|
|
case cpu_to_be16(ETH_P_IPV6):
|
|
if (!tcf_csum_ipv6(skb, update_flags))
|
|
goto drop;
|
|
break;
|
|
}
|
|
|
|
return action;
|
|
|
|
drop:
|
|
spin_lock(&p->tcf_lock);
|
|
p->tcf_qstats.drops++;
|
|
spin_unlock(&p->tcf_lock);
|
|
return TC_ACT_SHOT;
|
|
}
|
|
|
|
static int tcf_csum_dump(struct sk_buff *skb,
|
|
struct tc_action *a, int bind, int ref)
|
|
{
|
|
unsigned char *b = skb_tail_pointer(skb);
|
|
struct tcf_csum *p = a->priv;
|
|
struct tc_csum opt = {
|
|
.update_flags = p->update_flags,
|
|
.index = p->tcf_index,
|
|
.action = p->tcf_action,
|
|
.refcnt = p->tcf_refcnt - ref,
|
|
.bindcnt = p->tcf_bindcnt - bind,
|
|
};
|
|
struct tcf_t t;
|
|
|
|
if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
|
|
goto nla_put_failure;
|
|
|
|
tcf_tm_dump(&t, &p->tcf_tm);
|
|
if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
|
|
goto nla_put_failure;
|
|
|
|
return skb->len;
|
|
|
|
nla_put_failure:
|
|
nlmsg_trim(skb, b);
|
|
return -1;
|
|
}
|
|
|
|
static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
|
|
struct netlink_callback *cb, int type,
|
|
struct tc_action *a)
|
|
{
|
|
struct tc_action_net *tn = net_generic(net, csum_net_id);
|
|
|
|
return tcf_generic_walker(tn, skb, cb, type, a);
|
|
}
|
|
|
|
static int tcf_csum_search(struct net *net, struct tc_action *a, u32 index)
|
|
{
|
|
struct tc_action_net *tn = net_generic(net, csum_net_id);
|
|
|
|
return tcf_hash_search(tn, a, index);
|
|
}
|
|
|
|
static struct tc_action_ops act_csum_ops = {
|
|
.kind = "csum",
|
|
.type = TCA_ACT_CSUM,
|
|
.owner = THIS_MODULE,
|
|
.act = tcf_csum,
|
|
.dump = tcf_csum_dump,
|
|
.init = tcf_csum_init,
|
|
.walk = tcf_csum_walker,
|
|
.lookup = tcf_csum_search,
|
|
};
|
|
|
|
static __net_init int csum_init_net(struct net *net)
|
|
{
|
|
struct tc_action_net *tn = net_generic(net, csum_net_id);
|
|
|
|
return tc_action_net_init(tn, &act_csum_ops, CSUM_TAB_MASK);
|
|
}
|
|
|
|
static void __net_exit csum_exit_net(struct net *net)
|
|
{
|
|
struct tc_action_net *tn = net_generic(net, csum_net_id);
|
|
|
|
tc_action_net_exit(tn);
|
|
}
|
|
|
|
static struct pernet_operations csum_net_ops = {
|
|
.init = csum_init_net,
|
|
.exit = csum_exit_net,
|
|
.id = &csum_net_id,
|
|
.size = sizeof(struct tc_action_net),
|
|
};
|
|
|
|
MODULE_DESCRIPTION("Checksum updating actions");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static int __init csum_init_module(void)
|
|
{
|
|
return tcf_register_action(&act_csum_ops, &csum_net_ops);
|
|
}
|
|
|
|
static void __exit csum_cleanup_module(void)
|
|
{
|
|
tcf_unregister_action(&act_csum_ops, &csum_net_ops);
|
|
}
|
|
|
|
module_init(csum_init_module);
|
|
module_exit(csum_cleanup_module);
|