tuna2134/etherip-kmod
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fix

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tuna2134
2026-07-11 12:27:50 +09:00
parent 5ac8f37aca
commit fccfaf6249
2 changed files with 54 additions and 127 deletions
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167
etherip6.c
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@@ -3,9 +3,7 @@
#include <linux/if_ether.h>
#include <linux/if_link.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_vlan.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
@@ -15,17 +13,13 @@
#include <linux/rculist.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/unaligned.h>
#include <net/checksum.h>
#include <net/ip.h>
#include <net/ip6_route.h>
#include <net/ipv6.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/gso.h>
#include <net/protocol.h>
#include <net/rtnetlink.h>
#include <net/tcp.h>
#include "etherip6_uapi.h"
@@ -38,9 +32,7 @@
#define ETHERIP6_HLEN 2
#define ETHERIP6_DEFAULT_HOP_LIMIT 64
#define ETHERIP6_MAX_MTU 9000
/* IPv6 + EtherIP headers added outside the encapsulated Ethernet frame. */
#define ETHERIP6_OUTER_HLEN (sizeof(struct ipv6hdr) + ETHERIP6_HLEN)
#define ETHERIP6_NEEDED_HEADROOM (sizeof(struct ipv6hdr) + ETHERIP6_HLEN)
struct etherip6_tunnel {
struct list_head list;
@@ -149,111 +141,7 @@ static struct etherip6_tunnel *etherip6_lookup_rx(struct net *net,
return etherip6_lookup_unique_rx(net, local, remote, iif, false, false);
}
static void etherip6_clamp_tcp_mss(struct sk_buff *skb, unsigned int path_mtu)
{
struct vlan_hdr _vh, *vh;
struct tcphdr _th, *th;
struct ethhdr _eth, *eth;
unsigned int nhoff = ETH_HLEN;
unsigned int thoff, tcp_hlen;
unsigned int inner_mtu;
unsigned int min_ip_hlen;
unsigned char *opt;
unsigned int optlen;
__be16 proto;
u16 old_mss, new_mss;
u8 nexthdr;
eth = skb_header_pointer(skb, 0, sizeof(_eth), &_eth);
if (!eth)
return;
proto = eth->h_proto;
while (eth_type_vlan(proto)) {
vh = skb_header_pointer(skb, nhoff, sizeof(_vh), &_vh);
if (!vh)
return;
proto = vh->h_vlan_encapsulated_proto;
nhoff += sizeof(*vh);
}
if (path_mtu <= ETHERIP6_OUTER_HLEN + nhoff)
return;
inner_mtu = min_t(unsigned int, skb->dev->mtu,
path_mtu - ETHERIP6_OUTER_HLEN - nhoff);
if (proto == htons(ETH_P_IP)) {
struct iphdr _iph, *iph;
iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
if (!iph || iph->version != 4 || iph->ihl < 5 ||
iph->protocol != IPPROTO_TCP ||
(iph->frag_off & htons(IP_MF | IP_OFFSET)))
return;
thoff = nhoff + iph->ihl * 4;
min_ip_hlen = sizeof(struct iphdr);
} else if (proto == htons(ETH_P_IPV6)) {
struct ipv6hdr _ip6h, *ip6h;
__be16 frag_off = 0;
int offset;
ip6h = skb_header_pointer(skb, nhoff, sizeof(_ip6h), &_ip6h);
if (!ip6h || ip6h->version != 6)
return;
nexthdr = ip6h->nexthdr;
offset = ipv6_skip_exthdr(skb, nhoff + sizeof(*ip6h),
&nexthdr, &frag_off);
if (offset < 0 || nexthdr != IPPROTO_TCP || frag_off)
return;
thoff = offset;
min_ip_hlen = sizeof(struct ipv6hdr);
} else {
return;
}
th = skb_header_pointer(skb, thoff, sizeof(_th), &_th);
if (!th || !th->syn || th->doff < sizeof(*th) / 4)
return;
tcp_hlen = th->doff * 4;
if (inner_mtu <= min_ip_hlen + sizeof(*th))
return;
new_mss = min_t(unsigned int, U16_MAX,
inner_mtu - min_ip_hlen - sizeof(*th));
if (skb_ensure_writable(skb, thoff + tcp_hlen))
return;
th = (struct tcphdr *)(skb->data + thoff);
opt = (unsigned char *)(th + 1);
optlen = tcp_hlen - sizeof(*th);
while (optlen) {
u8 kind = opt[0];
u8 len;
if (kind == TCPOPT_EOL)
return;
if (kind == TCPOPT_NOP) {
opt++;
optlen--;
continue;
}
if (optlen < 2 || (len = opt[1]) < 2 || len > optlen)
return;
if (kind == TCPOPT_MSS && len == TCPOLEN_MSS) {
old_mss = get_unaligned_be16(opt + 2);
if (old_mss > new_mss) {
put_unaligned_be16(new_mss, opt + 2);
inet_proto_csum_replace2(&th->check, skb,
htons(old_mss), htons(new_mss), false);
}
return;
}
opt += len;
optlen -= len;
}
}
static netdev_tx_t etherip6_xmit(struct sk_buff *skb, struct net_device *dev)
static void etherip6_xmit_one(struct sk_buff *skb, struct net_device *dev)
{
struct etherip6_tunnel *tun = netdev_priv(dev);
struct net *net = dev_net(dev);
@@ -281,8 +169,6 @@ static netdev_tx_t etherip6_xmit(struct sk_buff *skb, struct net_device *dev)
goto tx_error;
}
etherip6_clamp_tcp_mss(skb, dst_mtu(dst));
headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(*ip6h) + ETHERIP6_HLEN;
err = skb_cow_head(skb, headroom);
if (err) {
@@ -323,7 +209,7 @@ static netdev_tx_t etherip6_xmit(struct sk_buff *skb, struct net_device *dev)
err = ip6_local_out(net, NULL, skb);
if (unlikely(net_xmit_eval(err))) {
atomic_long_inc(&tun->tx_dropped);
return NETDEV_TX_OK;
return;
}
stats = this_cpu_ptr(tun->stats);
@@ -332,11 +218,45 @@ static netdev_tx_t etherip6_xmit(struct sk_buff *skb, struct net_device *dev)
u64_stats_add(&stats->tx_bytes, inner_len);
u64_stats_update_end(&stats->syncp);
return NETDEV_TX_OK;
return;
tx_error:
atomic_long_inc(&tun->tx_dropped);
dev_kfree_skb(skb);
return;
}
static netdev_tx_t etherip6_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct etherip6_tunnel *tun = netdev_priv(dev);
struct sk_buff *segs, *nskb;
if (!skb_is_gso(skb)) {
etherip6_xmit_one(skb, dev);
return NETDEV_TX_OK;
}
/*
* EtherIP has no hardware GSO type. Segment the inner Ethernet frame
* before adding the EtherIP and outer IPv6 headers. Each resulting skb
* is then a normal IPv6 packet and can be fragmented by ip6_local_out()
* when the outer path MTU is smaller than the tunnel MTU.
*/
segs = skb_gso_segment(skb, 0);
if (IS_ERR_OR_NULL(segs)) {
atomic_long_inc(&tun->tx_dropped);
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
consume_skb(skb);
while (segs) {
nskb = segs;
segs = segs->next;
nskb->next = NULL;
etherip6_xmit_one(nskb, dev);
}
return NETDEV_TX_OK;
}
@@ -379,9 +299,12 @@ static void etherip6_setup(struct net_device *dev)
dev->needs_free_netdev = true;
dev->type = ARPHRD_ETHER;
dev->flags &= ~IFF_NOARP;
dev->features &= ~(NETIF_F_GSO_MASK | NETIF_F_CSUM_MASK);
dev->hw_features = 0;
dev->vlan_features = 0;
dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM |
NETIF_F_GSO_SOFTWARE;
dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM |
NETIF_F_GSO_SOFTWARE;
dev->vlan_features = dev->features;
dev->needed_headroom = ETHERIP6_NEEDED_HEADROOM;
dev->min_mtu = ETH_MIN_MTU;
dev->max_mtu = ETHERIP6_MAX_MTU;
eth_hw_addr_random(dev);