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	Add a new nsh/ directory. It currently holds only GSO functions but more will come: in particular, code shared by openvswitch and tc to manipulate NSH headers. For now, assume there's no hardware support for NSH segmentation. We can always introduce netdev->nsh_features later. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			91 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Network Service Header
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 *
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 * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com>
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 */
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <net/nsh.h>
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#include <net/tun_proto.h>
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static struct sk_buff *nsh_gso_segment(struct sk_buff *skb,
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				       netdev_features_t features)
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{
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	struct sk_buff *segs = ERR_PTR(-EINVAL);
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	unsigned int nsh_len, mac_len;
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	__be16 proto;
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	int nhoff;
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	skb_reset_network_header(skb);
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	nhoff = skb->network_header - skb->mac_header;
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	mac_len = skb->mac_len;
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	if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN)))
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		goto out;
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	nsh_len = nsh_hdr_len(nsh_hdr(skb));
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	if (unlikely(!pskb_may_pull(skb, nsh_len)))
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		goto out;
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	proto = tun_p_to_eth_p(nsh_hdr(skb)->np);
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	if (!proto)
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		goto out;
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	__skb_pull(skb, nsh_len);
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	skb_reset_mac_header(skb);
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	skb_reset_mac_len(skb);
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	skb->protocol = proto;
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	features &= NETIF_F_SG;
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	segs = skb_mac_gso_segment(skb, features);
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	if (IS_ERR_OR_NULL(segs)) {
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		skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len,
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				     skb->network_header - nhoff,
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				     mac_len);
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		goto out;
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	}
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	for (skb = segs; skb; skb = skb->next) {
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		skb->protocol = htons(ETH_P_NSH);
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		__skb_push(skb, nsh_len);
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		skb_set_mac_header(skb, -nhoff);
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		skb->network_header = skb->mac_header + mac_len;
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		skb->mac_len = mac_len;
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	}
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out:
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	return segs;
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}
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static struct packet_offload nsh_packet_offload __read_mostly = {
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	.type = htons(ETH_P_NSH),
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	.priority = 15,
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	.callbacks = {
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		.gso_segment = nsh_gso_segment,
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	},
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};
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static int __init nsh_init_module(void)
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{
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	dev_add_offload(&nsh_packet_offload);
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	return 0;
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}
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static void __exit nsh_cleanup_module(void)
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{
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	dev_remove_offload(&nsh_packet_offload);
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}
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module_init(nsh_init_module);
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module_exit(nsh_cleanup_module);
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MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>");
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MODULE_DESCRIPTION("NSH protocol");
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MODULE_LICENSE("GPL v2");
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