1/*
2 * Copyright (c) 2013 Nicira, Inc.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16 * 02110-1301, USA
17 */
18
19#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/skbuff.h>
24#include <linux/netdevice.h>
25#include <linux/in.h>
26#include <linux/if_arp.h>
27#include <linux/mroute.h>
28#include <linux/init.h>
29#include <linux/in6.h>
30#include <linux/inetdevice.h>
31#include <linux/netfilter_ipv4.h>
32#include <linux/etherdevice.h>
33#include <linux/if_ether.h>
34#include <linux/if_vlan.h>
35
36#include <net/ip.h>
37#include <net/icmp.h>
38#include <net/protocol.h>
39#include <net/ip_tunnels.h>
40#include <net/arp.h>
41#include <net/checksum.h>
42#include <net/dsfield.h>
43#include <net/inet_ecn.h>
44#include <net/xfrm.h>
45#include <net/net_namespace.h>
46#include <net/netns/generic.h>
47#include <net/rtnetlink.h>
48
49int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
50		  __be32 src, __be32 dst, __u8 proto,
51		  __u8 tos, __u8 ttl, __be16 df, bool xnet)
52{
53	int pkt_len = skb->len;
54	struct iphdr *iph;
55	int err;
56
57	skb_scrub_packet(skb, xnet);
58
59	skb_clear_hash(skb);
60	skb_dst_set(skb, &rt->dst);
61	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
62
63	/* Push down and install the IP header. */
64	skb_push(skb, sizeof(struct iphdr));
65	skb_reset_network_header(skb);
66
67	iph = ip_hdr(skb);
68
69	iph->version	=	4;
70	iph->ihl	=	sizeof(struct iphdr) >> 2;
71	iph->frag_off	=	df;
72	iph->protocol	=	proto;
73	iph->tos	=	tos;
74	iph->daddr	=	dst;
75	iph->saddr	=	src;
76	iph->ttl	=	ttl;
77	__ip_select_ident(dev_net(rt->dst.dev), iph,
78			  skb_shinfo(skb)->gso_segs ?: 1);
79
80	err = ip_local_out_sk(sk, skb);
81	if (unlikely(net_xmit_eval(err)))
82		pkt_len = 0;
83	return pkt_len;
84}
85EXPORT_SYMBOL_GPL(iptunnel_xmit);
86
87int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
88{
89	if (unlikely(!pskb_may_pull(skb, hdr_len)))
90		return -ENOMEM;
91
92	skb_pull_rcsum(skb, hdr_len);
93
94	if (inner_proto == htons(ETH_P_TEB)) {
95		struct ethhdr *eh;
96
97		if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
98			return -ENOMEM;
99
100		eh = (struct ethhdr *)skb->data;
101		if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
102			skb->protocol = eh->h_proto;
103		else
104			skb->protocol = htons(ETH_P_802_2);
105
106	} else {
107		skb->protocol = inner_proto;
108	}
109
110	nf_reset(skb);
111	secpath_reset(skb);
112	skb_clear_hash_if_not_l4(skb);
113	skb_dst_drop(skb);
114	skb->vlan_tci = 0;
115	skb_set_queue_mapping(skb, 0);
116	skb->pkt_type = PACKET_HOST;
117	return 0;
118}
119EXPORT_SYMBOL_GPL(iptunnel_pull_header);
120
121struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
122					 bool csum_help,
123					 int gso_type_mask)
124{
125	int err;
126
127	if (likely(!skb->encapsulation)) {
128		skb_reset_inner_headers(skb);
129		skb->encapsulation = 1;
130	}
131
132	if (skb_is_gso(skb)) {
133		err = skb_unclone(skb, GFP_ATOMIC);
134		if (unlikely(err))
135			goto error;
136		skb_shinfo(skb)->gso_type |= gso_type_mask;
137		return skb;
138	}
139
140	/* If packet is not gso and we are resolving any partial checksum,
141	 * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL
142	 * on the outer header without confusing devices that implement
143	 * NETIF_F_IP_CSUM with encapsulation.
144	 */
145	if (csum_help)
146		skb->encapsulation = 0;
147
148	if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
149		err = skb_checksum_help(skb);
150		if (unlikely(err))
151			goto error;
152	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
153		skb->ip_summed = CHECKSUM_NONE;
154
155	return skb;
156error:
157	kfree_skb(skb);
158	return ERR_PTR(err);
159}
160EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
161
162/* Often modified stats are per cpu, other are shared (netdev->stats) */
163struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
164						struct rtnl_link_stats64 *tot)
165{
166	int i;
167
168	for_each_possible_cpu(i) {
169		const struct pcpu_sw_netstats *tstats =
170						   per_cpu_ptr(dev->tstats, i);
171		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
172		unsigned int start;
173
174		do {
175			start = u64_stats_fetch_begin_irq(&tstats->syncp);
176			rx_packets = tstats->rx_packets;
177			tx_packets = tstats->tx_packets;
178			rx_bytes = tstats->rx_bytes;
179			tx_bytes = tstats->tx_bytes;
180		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
181
182		tot->rx_packets += rx_packets;
183		tot->tx_packets += tx_packets;
184		tot->rx_bytes   += rx_bytes;
185		tot->tx_bytes   += tx_bytes;
186	}
187
188	tot->multicast = dev->stats.multicast;
189
190	tot->rx_crc_errors = dev->stats.rx_crc_errors;
191	tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
192	tot->rx_length_errors = dev->stats.rx_length_errors;
193	tot->rx_frame_errors = dev->stats.rx_frame_errors;
194	tot->rx_errors = dev->stats.rx_errors;
195
196	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
197	tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
198	tot->tx_dropped = dev->stats.tx_dropped;
199	tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
200	tot->tx_errors = dev->stats.tx_errors;
201
202	tot->collisions  = dev->stats.collisions;
203
204	return tot;
205}
206EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);
207