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(iph, &rt->dst, (skb_shinfo(skb)->gso_segs ?: 1) - 1);
 78
 79	err = ip_local_out_sk(sk, skb);
 80	if (unlikely(net_xmit_eval(err)))
 81		pkt_len = 0;
 82	return pkt_len;
 83}
 84EXPORT_SYMBOL_GPL(iptunnel_xmit);
 85
 86int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
 87{
 88	if (unlikely(!pskb_may_pull(skb, hdr_len)))
 89		return -ENOMEM;
 90
 91	skb_pull_rcsum(skb, hdr_len);
 92
 93	if (inner_proto == htons(ETH_P_TEB)) {
 94		struct ethhdr *eh = (struct ethhdr *)skb->data;
 95
 96		if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 97			return -ENOMEM;
 98
 99		if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
100			skb->protocol = eh->h_proto;
101		else
102			skb->protocol = htons(ETH_P_802_2);
103
104	} else {
105		skb->protocol = inner_proto;
106	}
107
108	nf_reset(skb);
109	secpath_reset(skb);
110	skb_clear_hash_if_not_l4(skb);
111	skb_dst_drop(skb);
112	skb->vlan_tci = 0;
113	skb_set_queue_mapping(skb, 0);
114	skb->pkt_type = PACKET_HOST;
115	return 0;
116}
117EXPORT_SYMBOL_GPL(iptunnel_pull_header);
118
119struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
120					 bool csum_help,
121					 int gso_type_mask)
122{
123	int err;
124
125	if (likely(!skb->encapsulation)) {
126		skb_reset_inner_headers(skb);
127		skb->encapsulation = 1;
128	}
129
130	if (skb_is_gso(skb)) {
131		err = skb_unclone(skb, GFP_ATOMIC);
132		if (unlikely(err))
133			goto error;
134		skb_shinfo(skb)->gso_type |= gso_type_mask;
135		return skb;
136	}
137
138	if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
139		err = skb_checksum_help(skb);
140		if (unlikely(err))
141			goto error;
142	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
143		skb->ip_summed = CHECKSUM_NONE;
144
145	return skb;
146error:
147	kfree_skb(skb);
148	return ERR_PTR(err);
149}
150EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
151
152/* Often modified stats are per cpu, other are shared (netdev->stats) */
153struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
154						struct rtnl_link_stats64 *tot)
155{
156	int i;
157
158	for_each_possible_cpu(i) {
159		const struct pcpu_sw_netstats *tstats =
160						   per_cpu_ptr(dev->tstats, i);
161		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
162		unsigned int start;
163
164		do {
165			start = u64_stats_fetch_begin_irq(&tstats->syncp);
166			rx_packets = tstats->rx_packets;
167			tx_packets = tstats->tx_packets;
168			rx_bytes = tstats->rx_bytes;
169			tx_bytes = tstats->tx_bytes;
170		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
171
172		tot->rx_packets += rx_packets;
173		tot->tx_packets += tx_packets;
174		tot->rx_bytes   += rx_bytes;
175		tot->tx_bytes   += tx_bytes;
176	}
177
178	tot->multicast = dev->stats.multicast;
179
180	tot->rx_crc_errors = dev->stats.rx_crc_errors;
181	tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
182	tot->rx_length_errors = dev->stats.rx_length_errors;
183	tot->rx_frame_errors = dev->stats.rx_frame_errors;
184	tot->rx_errors = dev->stats.rx_errors;
185
186	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
187	tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
188	tot->tx_dropped = dev->stats.tx_dropped;
189	tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
190	tot->tx_errors = dev->stats.tx_errors;
191
192	tot->collisions  = dev->stats.collisions;
193
194	return tot;
195}
196EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);