#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/netlink.h>
#include <net/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/icmp.h>
#include <linux/icmpv6.h>
#include <linux/igmp.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/ip6_checksum.h>
#include <net/sctp/checksum.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>
#include <linux/tc_act/tc_csum.h>
#include <net/tc_act/tc_csum.h>
#include <net/tc_wrapper.h>
static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
};
static struct tc_action_ops act_csum_ops;
static int tcf_csum_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
struct tcf_proto *tp,
u32 flags, struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
bool bind = flags & TCA_ACT_FLAGS_BIND;
struct tcf_csum_params *params_new;
struct nlattr *tb[TCA_CSUM_MAX + 1];
struct tcf_chain *goto_ch = NULL;
struct tc_csum *parm;
struct tcf_csum *p;
int ret = 0, err;
u32 index;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested_deprecated(tb, TCA_CSUM_MAX, nla, csum_policy,
NULL);
if (err < 0)
return err;
if (tb[TCA_CSUM_PARMS] == NULL)
return -EINVAL;
parm = nla_data(tb[TCA_CSUM_PARMS]);
index = parm->index;
err = tcf_idr_check_alloc(tn, &index, a, bind);
if (!err) {
ret = tcf_idr_create_from_flags(tn, index, est, a,
&act_csum_ops, bind, flags);
if (ret) {
tcf_idr_cleanup(tn, index);
return ret;
}
ret = ACT_P_CREATED;
} else if (err > 0) {
if (bind)
return 0;
if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
tcf_idr_release(*a, bind);
return -EEXIST;
}
} else {
return err;
}
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
if (err < 0)
goto release_idr;
p = to_tcf_csum(*a);
params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
if (unlikely(!params_new)) {
err = -ENOMEM;
goto put_chain;
}
params_new->update_flags = parm->update_flags;
spin_lock_bh(&p->tcf_lock);
goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
params_new = rcu_replace_pointer(p->params, params_new,
lockdep_is_held(&p->tcf_lock));
spin_unlock_bh(&p->tcf_lock);
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
if (params_new)
kfree_rcu(params_new, rcu);
return ret;
put_chain:
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
release_idr:
tcf_idr_release(*a, bind);
return err;
}
static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
unsigned int ihl, unsigned int ipl,
unsigned int jhl)
{
int ntkoff = skb_network_offset(skb);
int hl = ihl + jhl;
if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
skb_try_make_writable(skb, hl + ntkoff))
return NULL;
else
return (void *)(skb_network_header(skb) + ihl);
}
static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl)
{
struct icmphdr *icmph;
icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
if (icmph == NULL)
return 0;
icmph->checksum = 0;
skb->csum = csum_partial(icmph, ipl - ihl, 0);
icmph->checksum = csum_fold(skb->csum);
skb->ip_summed = CHECKSUM_NONE;
return 1;
}
static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
unsigned int ihl, unsigned int ipl)
{
struct igmphdr *igmph;
igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
if (igmph == NULL)
return 0;
igmph->csum = 0;
skb->csum = csum_partial(igmph, ipl - ihl, 0);
igmph->csum = csum_fold(skb->csum);
skb->ip_summed = CHECKSUM_NONE;
return 1;
}
static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl)
{
struct icmp6hdr *icmp6h;
const struct ipv6hdr *ip6h;
icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
if (icmp6h == NULL)
return 0;
ip6h = ipv6_hdr(skb);
icmp6h->icmp6_cksum = 0;
skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
ipl - ihl, IPPROTO_ICMPV6,
skb->csum);
skb->ip_summed = CHECKSUM_NONE;
return 1;
}
static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl)
{
struct tcphdr *tcph;
const struct iphdr *iph;
if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
return 1;
tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
if (tcph == NULL)
return 0;
iph = ip_hdr(skb);
tcph->check = 0;
skb->csum = csum_partial(tcph, ipl - ihl, 0);
tcph->check = tcp_v4_check(ipl - ihl,
iph->saddr, iph->daddr, skb->csum);
skb->ip_summed = CHECKSUM_NONE;
return 1;
}
static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl)
{
struct tcphdr *tcph;
const struct ipv6hdr *ip6h;
if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
return 1;
tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
if (tcph == NULL)
return 0;
ip6h = ipv6_hdr(skb);
tcph->check = 0;
skb->csum = csum_partial(tcph, ipl - ihl, 0);
tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
ipl - ihl, IPPROTO_TCP,
skb->csum);
skb->ip_summed = CHECKSUM_NONE;
return 1;
}
static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl, int udplite)
{
struct udphdr *udph;
const struct iphdr *iph;
u16 ul;
if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
return 1;
udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
if (udph == NULL)
return 0;
iph = ip_hdr(skb);
ul = ntohs(udph->len);
if (udplite || udph->check) {
udph->check = 0;
if (udplite) {
if (ul == 0)
skb->csum = csum_partial(udph, ipl - ihl, 0);
else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
skb->csum = csum_partial(udph, ul, 0);
else
goto ignore_obscure_skb;
} else {
if (ul != ipl - ihl)
goto ignore_obscure_skb;
skb->csum = csum_partial(udph, ul, 0);
}
udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
ul, iph->protocol,
skb->csum);
if (!udph->check)
udph->check = CSUM_MANGLED_0;
}
skb->ip_summed = CHECKSUM_NONE;
ignore_obscure_skb:
return 1;
}
static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl, int udplite)
{
struct udphdr *udph;
const struct ipv6hdr *ip6h;
u16 ul;
if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
return 1;
udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
if (udph == NULL)
return 0;
ip6h = ipv6_hdr(skb);
ul = ntohs(udph->len);
udph->check = 0;
if (udplite) {
if (ul == 0)
skb->csum = csum_partial(udph, ipl - ihl, 0);
else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
skb->csum = csum_partial(udph, ul, 0);
else
goto ignore_obscure_skb;
} else {
if (ul != ipl - ihl)
goto ignore_obscure_skb;
skb->csum = csum_partial(udph, ul, 0);
}
udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
skb->csum);
if (!udph->check)
udph->check = CSUM_MANGLED_0;
skb->ip_summed = CHECKSUM_NONE;
ignore_obscure_skb:
return 1;
}
static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
unsigned int ipl)
{
struct sctphdr *sctph;
if (skb_is_gso(skb) && skb_is_gso_sctp(skb))
return 1;
sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
if (!sctph)
return 0;
sctph->checksum = sctp_compute_cksum(skb,
skb_network_offset(skb) + ihl);
skb_reset_csum_not_inet(skb);
return 1;
}
static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
{
const struct iphdr *iph;
int ntkoff;
ntkoff = skb_network_offset(skb);
if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
goto fail;
iph = ip_hdr(skb);
switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
case IPPROTO_ICMP:
if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
ntohs(iph->tot_len)))
goto fail;
break;
case IPPROTO_IGMP:
if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
ntohs(iph->tot_len)))
goto fail;
break;
case IPPROTO_TCP:
if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
ntohs(iph->tot_len)))
goto fail;
break;
case IPPROTO_UDP:
if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
ntohs(iph->tot_len), 0))
goto fail;
break;
case IPPROTO_UDPLITE:
if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
ntohs(iph->tot_len), 1))
goto fail;
break;
case IPPROTO_SCTP:
if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
!tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
goto fail;
break;
}
if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
goto fail;
ip_send_check(ip_hdr(skb));
}
return 1;
fail:
return 0;
}
static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
unsigned int *pl)
{
int off, len, optlen;
unsigned char *xh = (void *)ip6xh;
off = sizeof(*ip6xh);
len = ixhl - off;
while (len > 1) {
switch (xh[off]) {
case IPV6_TLV_PAD1:
optlen = 1;
break;
case IPV6_TLV_JUMBO:
optlen = xh[off + 1] + 2;
if (optlen != 6 || len < 6 || (off & 3) != 2)
return 0;
*pl = ntohl(*(__be32 *)(xh + off + 2));
goto done;
default:
optlen = xh[off + 1] + 2;
if (optlen > len)
goto done;
break;
}
off += optlen;
len -= optlen;
}
done:
return 1;
}
static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
{
struct ipv6hdr *ip6h;
struct ipv6_opt_hdr *ip6xh;
unsigned int hl, ixhl;
unsigned int pl;
int ntkoff;
u8 nexthdr;
ntkoff = skb_network_offset(skb);
hl = sizeof(*ip6h);
if (!pskb_may_pull(skb, hl + ntkoff))
goto fail;
ip6h = ipv6_hdr(skb);
pl = ntohs(ip6h->payload_len);
nexthdr = ip6h->nexthdr;
do {
switch (nexthdr) {
case NEXTHDR_FRAGMENT:
goto ignore_skb;
case NEXTHDR_ROUTING:
case NEXTHDR_HOP:
case NEXTHDR_DEST:
if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
goto fail;
ip6xh = (void *)(skb_network_header(skb) + hl);
ixhl = ipv6_optlen(ip6xh);
if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
goto fail;
ip6xh = (void *)(skb_network_header(skb) + hl);
if ((nexthdr == NEXTHDR_HOP) &&
!(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
goto fail;
nexthdr = ip6xh->nexthdr;
hl += ixhl;
break;
case IPPROTO_ICMPV6:
if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
if (!tcf_csum_ipv6_icmp(skb,
hl, pl + sizeof(*ip6h)))
goto fail;
goto done;
case IPPROTO_TCP:
if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
if (!tcf_csum_ipv6_tcp(skb,
hl, pl + sizeof(*ip6h)))
goto fail;
goto done;
case IPPROTO_UDP:
if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
if (!tcf_csum_ipv6_udp(skb, hl,
pl + sizeof(*ip6h), 0))
goto fail;
goto done;
case IPPROTO_UDPLITE:
if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
if (!tcf_csum_ipv6_udp(skb, hl,
pl + sizeof(*ip6h), 1))
goto fail;
goto done;
case IPPROTO_SCTP:
if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
!tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
goto fail;
goto done;
default:
goto ignore_skb;
}
} while (pskb_may_pull(skb, hl + 1 + ntkoff));
done:
ignore_skb:
return 1;
fail:
return 0;
}
TC_INDIRECT_SCOPE int tcf_csum_act(struct sk_buff *skb,
const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_csum *p = to_tcf_csum(a);
bool orig_vlan_tag_present = false;
unsigned int vlan_hdr_count = 0;
struct tcf_csum_params *params;
u32 update_flags;
__be16 protocol;
int action;
params = rcu_dereference_bh(p->params);
tcf_lastuse_update(&p->tcf_tm);
tcf_action_update_bstats(&p->common, skb);
action = READ_ONCE(p->tcf_action);
if (unlikely(action == TC_ACT_SHOT))
goto drop;
update_flags = params->update_flags;
protocol = skb_protocol(skb, false);
again:
switch (protocol) {
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;
case cpu_to_be16(ETH_P_8021AD):
fallthrough;
case cpu_to_be16(ETH_P_8021Q):
if (skb_vlan_tag_present(skb) && !orig_vlan_tag_present) {
protocol = skb->protocol;
orig_vlan_tag_present = true;
} else {
struct vlan_hdr *vlan = (struct vlan_hdr *)skb->data;
protocol = vlan->h_vlan_encapsulated_proto;
skb_pull(skb, VLAN_HLEN);
skb_reset_network_header(skb);
vlan_hdr_count++;
}
goto again;
}
out:
while (vlan_hdr_count--) {
skb_push(skb, VLAN_HLEN);
skb_reset_network_header(skb);
}
return action;
drop:
tcf_action_inc_drop_qstats(&p->common);
action = TC_ACT_SHOT;
goto out;
}
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 = to_tcf_csum(a);
struct tcf_csum_params *params;
struct tc_csum opt = {
.index = p->tcf_index,
.refcnt = refcount_read(&p->tcf_refcnt) - ref,
.bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
};
struct tcf_t t;
spin_lock_bh(&p->tcf_lock);
params = rcu_dereference_protected(p->params,
lockdep_is_held(&p->tcf_lock));
opt.action = p->tcf_action;
opt.update_flags = params->update_flags;
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;
spin_unlock_bh(&p->tcf_lock);
return skb->len;
nla_put_failure:
spin_unlock_bh(&p->tcf_lock);
nlmsg_trim(skb, b);
return -1;
}
static void tcf_csum_cleanup(struct tc_action *a)
{
struct tcf_csum *p = to_tcf_csum(a);
struct tcf_csum_params *params;
params = rcu_dereference_protected(p->params, 1);
if (params)
kfree_rcu(params, rcu);
}
static size_t tcf_csum_get_fill_size(const struct tc_action *act)
{
return nla_total_size(sizeof(struct tc_csum));
}
static int tcf_csum_offload_act_setup(struct tc_action *act, void *entry_data,
u32 *index_inc, bool bind,
struct netlink_ext_ack *extack)
{
if (bind) {
struct flow_action_entry *entry = entry_data;
entry->id = FLOW_ACTION_CSUM;
entry->csum_flags = tcf_csum_update_flags(act);
*index_inc = 1;
} else {
struct flow_offload_action *fl_action = entry_data;
fl_action->id = FLOW_ACTION_CSUM;
}
return 0;
}
static struct tc_action_ops act_csum_ops = {
.kind = "csum",
.id = TCA_ID_CSUM,
.owner = THIS_MODULE,
.act = tcf_csum_act,
.dump = tcf_csum_dump,
.init = tcf_csum_init,
.cleanup = tcf_csum_cleanup,
.get_fill_size = tcf_csum_get_fill_size,
.offload_act_setup = tcf_csum_offload_act_setup,
.size = sizeof(struct tcf_csum),
};
static __net_init int csum_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
return tc_action_net_init(net, tn, &act_csum_ops);
}
static void __net_exit csum_exit_net(struct list_head *net_list)
{
tc_action_net_exit(net_list, act_csum_ops.net_id);
}
static struct pernet_operations csum_net_ops = {
.init = csum_init_net,
.exit_batch = csum_exit_net,
.id = &act_csum_ops.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