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Pravin B Shelardavem330
Pravin B Shelar
authored and
davem330
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GRE: Refactor GRE tunneling code.
Following patch refactors GRE code into ip tunneling code and GRE specific code. Common tunneling code is moved to ip_tunnel module. ip_tunnel module is written as generic library which can be used by different tunneling implementations. ip_tunnel module contains following components: - packet xmit and rcv generic code. xmit flow looks like (gre_xmit/ipip_xmit)->ip_tunnel_xmit->ip_local_out. - hash table of all devices. - lookup for tunnel devices. - control plane operations like device create, destroy, ioctl, netlink operations code. - registration for tunneling modules, like gre, ipip etc. - define single pcpu_tstats dev->tstats. - struct tnl_ptk_info added to pass parsed tunnel packet parameters. ipip.h header is renamed to ip_tunnel.h Signed-off-by: Pravin B Shelar <[email protected]> Signed-off-by: David S. Miller <[email protected]>
1 parent eaac5f3 commit c544193

18 files changed

+1594
-1283
lines changed

‎drivers/net/vxlan.c

+1-1
Original file line numberDiff line numberDiff line change
@@ -33,7 +33,7 @@
3333
#include <net/arp.h>
3434
#include <net/ndisc.h>
3535
#include <net/ip.h>
36-
#include <net/ipip.h>
36+
#include <net/ip_tunnels.h>
3737
#include <net/icmp.h>
3838
#include <net/udp.h>
3939
#include <net/rtnetlink.h>

‎include/net/gre.h

+51
Original file line numberDiff line numberDiff line change
@@ -2,6 +2,7 @@
22
#define __LINUX_GRE_H
33

44
#include <linux/skbuff.h>
5+
#include <net/ip_tunnels.h>
56

67
#define GREPROTO_CISCO 0
78
#define GREPROTO_PPTP 1
@@ -12,7 +13,57 @@ struct gre_protocol {
1213
void (*err_handler)(struct sk_buff *skb, u32 info);
1314
};
1415

16+
struct gre_base_hdr {
17+
__be16 flags;
18+
__be16 protocol;
19+
};
20+
#define GRE_HEADER_SECTION 4
21+
1522
int gre_add_protocol(const struct gre_protocol *proto, u8 version);
1623
int gre_del_protocol(const struct gre_protocol *proto, u8 version);
1724

25+
static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
26+
{
27+
__be16 tflags = 0;
28+
29+
if (flags & GRE_CSUM)
30+
tflags |= TUNNEL_CSUM;
31+
if (flags & GRE_ROUTING)
32+
tflags |= TUNNEL_ROUTING;
33+
if (flags & GRE_KEY)
34+
tflags |= TUNNEL_KEY;
35+
if (flags & GRE_SEQ)
36+
tflags |= TUNNEL_SEQ;
37+
if (flags & GRE_STRICT)
38+
tflags |= TUNNEL_STRICT;
39+
if (flags & GRE_REC)
40+
tflags |= TUNNEL_REC;
41+
if (flags & GRE_VERSION)
42+
tflags |= TUNNEL_VERSION;
43+
44+
return tflags;
45+
}
46+
47+
static inline __be16 tnl_flags_to_gre_flags(__be16 tflags)
48+
{
49+
__be16 flags = 0;
50+
51+
if (tflags & TUNNEL_CSUM)
52+
flags |= GRE_CSUM;
53+
if (tflags & TUNNEL_ROUTING)
54+
flags |= GRE_ROUTING;
55+
if (tflags & TUNNEL_KEY)
56+
flags |= GRE_KEY;
57+
if (tflags & TUNNEL_SEQ)
58+
flags |= GRE_SEQ;
59+
if (tflags & TUNNEL_STRICT)
60+
flags |= GRE_STRICT;
61+
if (tflags & TUNNEL_REC)
62+
flags |= GRE_REC;
63+
if (tflags & TUNNEL_VERSION)
64+
flags |= GRE_VERSION;
65+
66+
return flags;
67+
}
68+
1869
#endif

‎include/net/ip6_tunnel.h

+1
Original file line numberDiff line numberDiff line change
@@ -3,6 +3,7 @@
33

44
#include <linux/ipv6.h>
55
#include <linux/netdevice.h>
6+
#include <linux/if_tunnel.h>
67
#include <linux/ip6_tunnel.h>
78

89
#define IP6TUNNEL_ERR_TIMEO (30*HZ)

‎include/net/ip_tunnels.h

+177
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,177 @@
1+
#ifndef __NET_IP_TUNNELS_H
2+
#define __NET_IP_TUNNELS_H 1
3+
4+
#include <linux/if_tunnel.h>
5+
#include <linux/netdevice.h>
6+
#include <linux/skbuff.h>
7+
#include <linux/types.h>
8+
#include <linux/u64_stats_sync.h>
9+
#include <net/dsfield.h>
10+
#include <net/gro_cells.h>
11+
#include <net/inet_ecn.h>
12+
#include <net/ip.h>
13+
#include <net/rtnetlink.h>
14+
15+
#if IS_ENABLED(CONFIG_IPV6)
16+
#include <net/ipv6.h>
17+
#include <net/ip6_fib.h>
18+
#include <net/ip6_route.h>
19+
#endif
20+
21+
/* Keep error state on tunnel for 30 sec */
22+
#define IPTUNNEL_ERR_TIMEO (30*HZ)
23+
24+
/* 6rd prefix/relay information */
25+
#ifdef CONFIG_IPV6_SIT_6RD
26+
struct ip_tunnel_6rd_parm {
27+
struct in6_addr prefix;
28+
__be32 relay_prefix;
29+
u16 prefixlen;
30+
u16 relay_prefixlen;
31+
};
32+
#endif
33+
34+
struct ip_tunnel_prl_entry {
35+
struct ip_tunnel_prl_entry __rcu *next;
36+
__be32 addr;
37+
u16 flags;
38+
struct rcu_head rcu_head;
39+
};
40+
41+
struct ip_tunnel {
42+
struct ip_tunnel __rcu *next;
43+
struct hlist_node hash_node;
44+
struct net_device *dev;
45+
46+
int err_count; /* Number of arrived ICMP errors */
47+
unsigned long err_time; /* Time when the last ICMP error
48+
* arrived */
49+
50+
/* These four fields used only by GRE */
51+
__u32 i_seqno; /* The last seen seqno */
52+
__u32 o_seqno; /* The last output seqno */
53+
int hlen; /* Precalculated header length */
54+
int mlink;
55+
56+
struct ip_tunnel_parm parms;
57+
58+
/* for SIT */
59+
#ifdef CONFIG_IPV6_SIT_6RD
60+
struct ip_tunnel_6rd_parm ip6rd;
61+
#endif
62+
struct ip_tunnel_prl_entry __rcu *prl; /* potential router list */
63+
unsigned int prl_count; /* # of entries in PRL */
64+
int ip_tnl_net_id;
65+
struct gro_cells gro_cells;
66+
};
67+
68+
#define TUNNEL_CSUM __cpu_to_be16(0x01)
69+
#define TUNNEL_ROUTING __cpu_to_be16(0x02)
70+
#define TUNNEL_KEY __cpu_to_be16(0x04)
71+
#define TUNNEL_SEQ __cpu_to_be16(0x08)
72+
#define TUNNEL_STRICT __cpu_to_be16(0x10)
73+
#define TUNNEL_REC __cpu_to_be16(0x20)
74+
#define TUNNEL_VERSION __cpu_to_be16(0x40)
75+
#define TUNNEL_NO_KEY __cpu_to_be16(0x80)
76+
77+
struct tnl_ptk_info {
78+
__be16 flags;
79+
__be16 proto;
80+
__be32 key;
81+
__be32 seq;
82+
};
83+
84+
#define PACKET_RCVD 0
85+
#define PACKET_REJECT 1
86+
87+
#define IP_TNL_HASH_BITS 10
88+
#define IP_TNL_HASH_SIZE (1 << IP_TNL_HASH_BITS)
89+
90+
struct ip_tunnel_net {
91+
struct hlist_head *tunnels;
92+
struct net_device *fb_tunnel_dev;
93+
};
94+
95+
int ip_tunnel_init(struct net_device *dev);
96+
void ip_tunnel_uninit(struct net_device *dev);
97+
void ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
98+
int __net_init ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
99+
struct rtnl_link_ops *ops, char *devname);
100+
101+
void __net_exit ip_tunnel_delete_net(struct ip_tunnel_net *itn);
102+
103+
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
104+
const struct iphdr *tnl_params);
105+
int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
106+
int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
107+
108+
struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
109+
struct rtnl_link_stats64 *tot);
110+
struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
111+
int link, __be16 flags,
112+
__be32 remote, __be32 local,
113+
__be32 key);
114+
115+
int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
116+
const struct tnl_ptk_info *tpi, bool log_ecn_error);
117+
int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
118+
struct ip_tunnel_parm *p);
119+
int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
120+
struct ip_tunnel_parm *p);
121+
void ip_tunnel_setup(struct net_device *dev, int net_id);
122+
123+
/* Extract dsfield from inner protocol */
124+
static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
125+
const struct sk_buff *skb)
126+
{
127+
if (skb->protocol == htons(ETH_P_IP))
128+
return iph->tos;
129+
else if (skb->protocol == htons(ETH_P_IPV6))
130+
return ipv6_get_dsfield((const struct ipv6hdr *)iph);
131+
else
132+
return 0;
133+
}
134+
135+
/* Propogate ECN bits out */
136+
static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
137+
const struct sk_buff *skb)
138+
{
139+
u8 inner = ip_tunnel_get_dsfield(iph, skb);
140+
141+
return INET_ECN_encapsulate(tos, inner);
142+
}
143+
144+
static inline void tunnel_ip_select_ident(struct sk_buff *skb,
145+
const struct iphdr *old_iph,
146+
struct dst_entry *dst)
147+
{
148+
struct iphdr *iph = ip_hdr(skb);
149+
150+
/* Use inner packet iph-id if possible. */
151+
if (skb->protocol == htons(ETH_P_IP) && old_iph->id)
152+
iph->id = old_iph->id;
153+
else
154+
__ip_select_ident(iph, dst,
155+
(skb_shinfo(skb)->gso_segs ?: 1) - 1);
156+
}
157+
158+
static inline void iptunnel_xmit(struct sk_buff *skb, struct net_device *dev)
159+
{
160+
int err;
161+
int pkt_len = skb->len - skb_transport_offset(skb);
162+
struct pcpu_tstats *tstats = this_cpu_ptr(dev->tstats);
163+
164+
nf_reset(skb);
165+
166+
err = ip_local_out(skb);
167+
if (likely(net_xmit_eval(err) == 0)) {
168+
u64_stats_update_begin(&tstats->syncp);
169+
tstats->tx_bytes += pkt_len;
170+
tstats->tx_packets++;
171+
u64_stats_update_end(&tstats->syncp);
172+
} else {
173+
dev->stats.tx_errors++;
174+
dev->stats.tx_aborted_errors++;
175+
}
176+
}
177+
#endif /* __NET_IP_TUNNELS_H */

‎include/net/ipip.h

-84
This file was deleted.

‎net/ipv4/Kconfig

+5
Original file line numberDiff line numberDiff line change
@@ -186,9 +186,14 @@ config NET_IPGRE_DEMUX
186186
This is helper module to demultiplex GRE packets on GRE version field criteria.
187187
Required by ip_gre and pptp modules.
188188

189+
config NET_IP_TUNNEL
190+
tristate
191+
default n
192+
189193
config NET_IPGRE
190194
tristate "IP: GRE tunnels over IP"
191195
depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
196+
select NET_IP_TUNNEL
192197
help
193198
Tunneling means encapsulating data of one protocol type within
194199
another protocol and sending it over a channel that understands the

‎net/ipv4/Makefile

+1
Original file line numberDiff line numberDiff line change
@@ -13,6 +13,7 @@ obj-y := route.o inetpeer.o protocol.o \
1313
fib_frontend.o fib_semantics.o fib_trie.o \
1414
inet_fragment.o ping.o
1515

16+
obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o
1617
obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
1718
obj-$(CONFIG_PROC_FS) += proc.o
1819
obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o

‎net/ipv4/af_inet.c

-1
Original file line numberDiff line numberDiff line change
@@ -111,7 +111,6 @@
111111
#include <net/sock.h>
112112
#include <net/raw.h>
113113
#include <net/icmp.h>
114-
#include <net/ipip.h>
115114
#include <net/inet_common.h>
116115
#include <net/xfrm.h>
117116
#include <net/net_namespace.h>

‎net/ipv4/gre.c

-5
Original file line numberDiff line numberDiff line change
@@ -27,11 +27,6 @@
2727

2828
static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;
2929
static DEFINE_SPINLOCK(gre_proto_lock);
30-
struct gre_base_hdr {
31-
__be16 flags;
32-
__be16 protocol;
33-
};
34-
#define GRE_HEADER_SECTION 4
3530

3631
int gre_add_protocol(const struct gre_protocol *proto, u8 version)
3732
{

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