cregit-Linux how code gets into the kernel

Release 4.11 net/ipv6/ip6_output.c

Directory: net/ipv6
/*
 *      IPv6 output functions
 *      Linux INET6 implementation
 *
 *      Authors:
 *      Pedro Roque             <roque@di.fc.ul.pt>
 *
 *      Based on linux/net/ipv4/ip_output.c
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *      Changes:
 *      A.N.Kuznetsov   :       airthmetics in fragmentation.
 *                              extension headers are implemented.
 *                              route changes now work.
 *                              ip6_forward does not confuse sniffers.
 *                              etc.
 *
 *      H. von Brand    :       Added missing #include <linux/string.h>
 *      Imran Patel     :       frag id should be in NBO
 *      Kazunori MIYAZAWA @USAGI
 *                      :       add ip6_append_data and related functions
 *                              for datagram xmit
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/in6.h>
#include <linux/tcp.h>
#include <linux/route.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <linux/bpf-cgroup.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>

#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/rawv6.h>
#include <net/icmp.h>
#include <net/xfrm.h>
#include <net/checksum.h>
#include <linux/mroute6.h>
#include <net/l3mdev.h>
#include <net/lwtunnel.h>




static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct net_device *dev = dst->dev;
	struct neighbour *neigh;
	struct in6_addr *nexthop;
	int ret;

	skb->protocol = htons(ETH_P_IPV6);
	skb->dev = dev;

	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));

		if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
		    ((mroute6_socket(net, skb) &&
		     !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
		     ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
					 &ipv6_hdr(skb)->saddr))) {
			struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);

			/* Do not check for IFF_ALLMULTI; multicast routing
                           is not supported in any case.
                         */
			if (newskb)
				NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
					net, sk, newskb, NULL, newskb->dev,
					dev_loopback_xmit);

			if (ipv6_hdr(skb)->hop_limit == 0) {
				IP6_INC_STATS(net, idev,
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return 0;
			}
		}

		IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);

		if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
		    IPV6_ADDR_SCOPE_NODELOCAL &&
		    !(dev->flags & IFF_LOOPBACK)) {
			kfree_skb(skb);
			return 0;
		}
	}

	if (lwtunnel_xmit_redirect(dst->lwtstate)) {
		int res = lwtunnel_xmit(skb);

		if (res < 0 || res == LWTUNNEL_XMIT_DONE)
			return res;
	}

	rcu_read_lock_bh();
	nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
	neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
	if (unlikely(!neigh))
		neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
	if (!IS_ERR(neigh)) {
		sock_confirm_neigh(skb, neigh);
		ret = neigh_output(neigh, skb);
		rcu_read_unlock_bh();
		return ret;
	}
	rcu_read_unlock_bh();

	IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
	kfree_skb(skb);
	return -EINVAL;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13131.26%716.67%


Hideaki Yoshifuji / 吉藤英明9322.20%511.90%


Hannes Frederic Sowa358.35%24.76%


Roopa Prabhu327.64%12.38%


David S. Miller327.64%614.29%


Jan Engelhardt225.25%24.76%


Arnaldo Carvalho de Melo122.86%12.38%


Eric W. Biedermann112.63%37.14%


Martin KaFai Lau81.91%12.38%


Julian Anastasov81.91%24.76%


Neil Horman61.43%12.38%


Eric Dumazet61.43%12.38%


Shirley Ma51.19%24.76%


David L Stevens51.19%12.38%


Octavian Purdila40.95%12.38%


Patrick McHardy30.72%24.76%


Benjamin Thery20.48%12.38%


Denis V. Lunev20.48%12.38%


Herbert Xu10.24%12.38%


Michel Machado10.24%12.38%


Total419100.00%42100.00%






static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	int ret;

	ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
	if (ret) {
		kfree_skb(skb);
		return ret;
	}

	if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
	    dst_allfrag(skb_dst(skb)) ||
	    (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
		return ip6_fragment(net, sk, skb, ip6_finish_output2);
	else
		return ip6_finish_output2(net, sk, skb);
}


Contributors
PersonTokensPropCommitsCommitProp
Jan Engelhardt5345.30%116.67%


Daniel Mack2622.22%116.67%


Jiri Pirko2017.09%116.67%


David S. Miller97.69%116.67%


Eric W. Biedermann97.69%233.33%


Total117100.00%6100.00%






int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct net_device *dev = skb_dst(skb)->dev;
	struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));

	if (unlikely(idev->cnf.disable_ipv6)) {
		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
		kfree_skb(skb);
		return 0;
	}

	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
			    net, sk, skb, NULL, dev,
			    ip6_finish_output,
			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
}


Contributors
PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明3835.51%18.33%


Jan Engelhardt3431.78%216.67%


Kazunori Miyazawa1413.08%18.33%


Eric Dumazet87.48%216.67%


Eric W. Biedermann87.48%325.00%


David S. Miller21.87%18.33%


Herbert Xu21.87%18.33%


Denis V. Lunev10.93%18.33%


Total107100.00%12100.00%



/*
 * xmit an sk_buff (used by TCP, SCTP and DCCP)
 * Note : socket lock is not held for SYNACK packets, but might be modified
 * by calls to skb_set_owner_w() and ipv6_local_error(),
 * which are using proper atomic operations or spinlocks.
 */



int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
	     __u32 mark, struct ipv6_txoptions *opt, int tclass)
{
	struct net *net = sock_net(sk);
	const struct ipv6_pinfo *np = inet6_sk(sk);
	struct in6_addr *first_hop = &fl6->daddr;
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *hdr;
	u8  proto = fl6->flowi6_proto;
	int seg_len = skb->len;
	int hlimit = -1;
	u32 mtu;

	if (opt) {
		unsigned int head_room;

		/* First: exthdrs may take lots of space (~8K for now)
                   MAX_HEADER is not enough.
                 */
		head_room = opt->opt_nflen + opt->opt_flen;
		seg_len += head_room;
		head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);

		if (skb_headroom(skb) < head_room) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
			if (!skb2) {
				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
					      IPSTATS_MIB_OUTDISCARDS);
				kfree_skb(skb);
				return -ENOBUFS;
			}
			consume_skb(skb);
			skb = skb2;
			/* skb_set_owner_w() changes sk->sk_wmem_alloc atomically,
                         * it is safe to call in our context (socket lock not held)
                         */
			skb_set_owner_w(skb, (struct sock *)sk);
		}
		if (opt->opt_flen)
			ipv6_push_frag_opts(skb, opt, &proto);
		if (opt->opt_nflen)
			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
					     &fl6->saddr);
	}

	skb_push(skb, sizeof(struct ipv6hdr));
	skb_reset_network_header(skb);
	hdr = ipv6_hdr(skb);

	/*
         *      Fill in the IPv6 header
         */
	if (np)
		hlimit = np->hop_limit;
	if (hlimit < 0)
		hlimit = ip6_dst_hoplimit(dst);

	ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
						     np->autoflowlabel, fl6));

	hdr->payload_len = htons(seg_len);
	hdr->nexthdr = proto;
	hdr->hop_limit = hlimit;

	hdr->saddr = fl6->saddr;
	hdr->daddr = *first_hop;

	skb->protocol = htons(ETH_P_IPV6);
	skb->priority = sk->sk_priority;
	skb->mark = mark;

	mtu = dst_mtu(dst);
	if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
		IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
			      IPSTATS_MIB_OUT, skb->len);

		/* if egress device is enslaved to an L3 master device pass the
                 * skb to its handler for processing
                 */
		skb = l3mdev_ip6_out((struct sock *)sk, skb);
		if (unlikely(!skb))
			return 0;

		/* hooks should never assume socket lock is held.
                 * we promote our socket to non const
                 */
		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
			       net, (struct sock *)sk, skb, NULL, dst->dev,
			       dst_output);
	}

	skb->dev = dst->dev;
	/* ipv6_local_error() does not require socket lock,
         * we promote our socket to non const
         */
	ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);

	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
	kfree_skb(skb);
	return -EMSGSIZE;
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)27350.84%916.36%


Hideaki Yoshifuji / 吉藤英明468.57%712.73%


Eric Dumazet366.70%47.27%


David Ahern264.84%11.82%


David S. Miller173.17%59.09%


Denis V. Lunev162.98%11.82%


Tom Herbert132.42%23.64%


Arnaldo Carvalho de Melo122.23%23.64%


Sridhar Samudrala112.05%11.82%


Alexey Kuznetsov112.05%11.82%


Shirley Ma101.86%11.82%


Patrick McHardy91.68%23.64%


Hannes Frederic Sowa91.68%11.82%


Neil Horman61.12%11.82%


Herbert Xu61.12%35.45%


David Lebrun50.93%11.82%


Tóth László Attila50.93%11.82%


Gerrit Renker40.74%11.82%


Pablo Neira Ayuso40.74%11.82%


Steffen Klassert40.74%11.82%


Alexey Dobriyan30.56%11.82%


Eric W. Biedermann30.56%23.64%


Kazunori Miyazawa20.37%11.82%


Wei Yongjun20.37%11.82%


Ian Morris10.19%11.82%


Américo Wang10.19%11.82%


Jan Engelhardt10.19%11.82%


Chuck Lever10.19%11.82%


Total537100.00%55100.00%




EXPORT_SYMBOL(ip6_xmit);




static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
{
	struct ip6_ra_chain *ra;
	struct sock *last = NULL;

	read_lock(&ip6_ra_lock);
	for (ra = ip6_ra_chain; ra; ra = ra->next) {
		struct sock *sk = ra->sk;
		if (sk && ra->sel == sel &&
		    (!sk->sk_bound_dev_if ||
		     sk->sk_bound_dev_if == skb->dev->ifindex)) {
			if (last) {
				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
				if (skb2)
					rawv6_rcv(last, skb2);
			}
			last = sk;
		}
	}

	if (last) {
		rawv6_rcv(last, skb);
		read_unlock(&ip6_ra_lock);
		return 1;
	}
	read_unlock(&ip6_ra_lock);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13288.00%360.00%


Andrew McDonald1711.33%120.00%


Adrian Bunk10.67%120.00%


Total150100.00%5100.00%






static int ip6_forward_proxy_check(struct sk_buff *skb)
{
	struct ipv6hdr *hdr = ipv6_hdr(skb);
	u8 nexthdr = hdr->nexthdr;
	__be16 frag_off;
	int offset;

	if (ipv6_ext_hdr(nexthdr)) {
		offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
		if (offset < 0)
			return 0;
	} else
		offset = sizeof(struct ipv6hdr);

	if (nexthdr == IPPROTO_ICMPV6) {
		struct icmp6hdr *icmp6;

		if (!pskb_may_pull(skb, (skb_network_header(skb) +
					 offset + 1 - skb->data)))
			return 0;

		icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);

		switch (icmp6->icmp6_type) {
		case NDISC_ROUTER_SOLICITATION:
		case NDISC_ROUTER_ADVERTISEMENT:
		case NDISC_NEIGHBOUR_SOLICITATION:
		case NDISC_NEIGHBOUR_ADVERTISEMENT:
		case NDISC_REDIRECT:
			/* For reaction involving unicast neighbor discovery
                         * message destined to the proxied address, pass it to
                         * input function.
                         */
			return 1;
		default:
			break;
		}
	}

	/*
         * The proxying router can't forward traffic sent to a link-local
         * address, so signal the sender and discard the packet. This
         * behavior is clarified by the MIPv6 specification.
         */
	if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
		dst_link_failure(skb);
		return -1;
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Ville Nuorvala17491.10%240.00%


Arnaldo Carvalho de Melo115.76%240.00%


Jesse Gross63.14%120.00%


Total191100.00%5100.00%






static inline int ip6_forward_finish(struct net *net, struct sock *sk,
				     struct sk_buff *skb)
{
	return dst_output(net, sk, skb);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1753.12%120.00%


Eric W. Biedermann825.00%360.00%


David S. Miller721.88%120.00%


Total32100.00%5100.00%






static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
{
	unsigned int mtu;
	struct inet6_dev *idev;

	if (dst_metric_locked(dst, RTAX_MTU)) {
		mtu = dst_metric_raw(dst, RTAX_MTU);
		if (mtu)
			return mtu;
	}

	mtu = IPV6_MIN_MTU;
	rcu_read_lock();
	idev = __in6_dev_get(dst->dev);
	if (idev)
		mtu = idev->cnf.mtu6;
	rcu_read_unlock();

	return mtu;
}


Contributors
PersonTokensPropCommitsCommitProp
Hannes Frederic Sowa83100.00%1100.00%


Total83100.00%1100.00%






static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
{
	if (skb->len <= mtu)
		return false;

	/* ipv6 conntrack defrag sets max_frag_size + ignore_df */
	if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
		return true;

	if (skb->ignore_df)
		return false;

	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
		return false;

	return true;
}


Contributors
PersonTokensPropCommitsCommitProp
Florian Westphal7393.59%250.00%


Marcelo Ricardo Leitner33.85%125.00%


Américo Wang22.56%125.00%


Total78100.00%4100.00%






int ip6_forward(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *hdr = ipv6_hdr(skb);
	struct inet6_skb_parm *opt = IP6CB(skb);
	struct net *net = dev_net(dst->dev);
	u32 mtu;

	if (net->ipv6.devconf_all->forwarding == 0)
		goto error;

	if (skb->pkt_type != PACKET_HOST)
		goto drop;

	if (unlikely(skb->sk))
		goto drop;

	if (skb_warn_if_lro(skb))
		goto drop;

	if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
		__IP6_INC_STATS(net, ip6_dst_idev(dst),
				IPSTATS_MIB_INDISCARDS);
		goto drop;
	}

	skb_forward_csum(skb);

	/*
         *      We DO NOT make any processing on
         *      RA packets, pushing them to user level AS IS
         *      without ane WARRANTY that application will be able
         *      to interpret them. The reason is that we
         *      cannot make anything clever here.
         *
         *      We are not end-node, so that if packet contains
         *      AH/ESP, we cannot make anything.
         *      Defragmentation also would be mistake, RA packets
         *      cannot be fragmented, because there is no warranty
         *      that different fragments will go along one path. --ANK
         */
	if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
		if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
			return 0;
	}

	/*
         *      check and decrement ttl
         */
	if (hdr->hop_limit <= 1) {
		/* Force OUTPUT device used as source address */
		skb->dev = dst->dev;
		icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
		__IP6_INC_STATS(net, ip6_dst_idev(dst),
				IPSTATS_MIB_INHDRERRORS);

		kfree_skb(skb);
		return -ETIMEDOUT;
	}

	/* XXX: idev->cnf.proxy_ndp? */
	if (net->ipv6.devconf_all->proxy_ndp &&
	    pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
		int proxied = ip6_forward_proxy_check(skb);
		if (proxied > 0)
			return ip6_input(skb);
		else if (proxied < 0) {
			__IP6_INC_STATS(net, ip6_dst_idev(dst),
					IPSTATS_MIB_INDISCARDS);
			goto drop;
		}
	}

	if (!xfrm6_route_forward(skb)) {
		__IP6_INC_STATS(net, ip6_dst_idev(dst),
				IPSTATS_MIB_INDISCARDS);
		goto drop;
	}
	dst = skb_dst(skb);

	/* IPv6 specs say nothing about it, but it is clear that we cannot
           send redirects to source routed frames.
           We don't send redirects to frames decapsulated from IPsec.
         */
	if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
		struct in6_addr *target = NULL;
		struct inet_peer *peer;
		struct rt6_info *rt;

		/*
                 *      incoming and outgoing devices are the same
                 *      send a redirect.
                 */

		rt = (struct rt6_info *) dst;
		if (rt->rt6i_flags & RTF_GATEWAY)
			target = &rt->rt6i_gateway;
		else
			target = &hdr->daddr;

		peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);

		/* Limit redirects both by destination (here)
                   and by source (inside ndisc_send_redirect)
                 */
		if (inet_peer_xrlim_allow(peer, 1*HZ))
			ndisc_send_redirect(skb, target);
		if (peer)
			inet_putpeer(peer);
	} else {
		int addrtype = ipv6_addr_type(&hdr->saddr);

		/* This check is security critical. */
		if (addrtype == IPV6_ADDR_ANY ||
		    addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
			goto error;
		if (addrtype & IPV6_ADDR_LINKLOCAL) {
			icmpv6_send(skb, ICMPV6_DEST_UNREACH,
				    ICMPV6_NOT_NEIGHBOUR, 0);
			goto error;
		}
	}

	mtu = ip6_dst_mtu_forward(dst);
	if (mtu < IPV6_MIN_MTU)
		mtu = IPV6_MIN_MTU;

	if (ip6_pkt_too_big(skb, mtu)) {
		/* Again, force OUTPUT device used as source address */
		skb->dev = dst->dev;
		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
		__IP6_INC_STATS(net, ip6_dst_idev(dst),
				IPSTATS_MIB_INTOOBIGERRORS);
		__IP6_INC_STATS(net, ip6_dst_idev(dst),
				IPSTATS_MIB_FRAGFAILS);
		kfree_skb(skb);
		return -EMSGSIZE;
	}

	if (skb_cow(skb, dst->dev->hard_header_len)) {
		__IP6_INC_STATS(net, ip6_dst_idev(dst),
				IPSTATS_MIB_OUTDISCARDS);
		goto drop;
	}

	hdr = ipv6_hdr(skb);

	/* Mangling hops number delayed to point after skb COW */

	hdr->hop_limit--;

	__IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
	__IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
		       net, NULL, skb, skb->dev, dst->dev,
		       ip6_forward_finish);

error:
	__IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
drop:
	kfree_skb(skb);
	return -EINVAL;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)28840.91%815.69%


Hideaki Yoshifuji / 吉藤英明8812.50%815.69%


Ville Nuorvala567.95%23.92%


David S. Miller365.11%59.80%


David L Stevens314.40%11.96%


Tom Lendacky263.69%11.96%


Ulrich Weber202.84%11.96%


Shirley Ma182.56%11.96%


Denis V. Lunev182.56%23.92%


Eric Dumazet162.27%23.92%


Vincent Bernat152.13%11.96%


Hannes Frederic Sowa131.85%23.92%


Li RongQing111.56%11.96%


Linus Torvalds101.42%11.96%


Daniel Lezcano101.42%11.96%


Ben Hutchings101.42%11.96%


Herbert Xu70.99%23.92%


Arnaldo Carvalho de Melo60.85%11.96%


Eric W. Biedermann40.57%23.92%


Wei Dong40.57%11.96%


Patrick McHardy40.57%23.92%


Masahide Nakamura40.57%11.96%


Florian Westphal30.43%11.96%


Alexey Dobriyan30.43%11.96%


Martin KaFai Lau20.28%11.96%


Jan Engelhardt10.14%11.96%


Total704100.00%51100.00%






static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
{
	to->pkt_type = from->pkt_type;
	to->priority = from->priority;
	to->protocol = from->protocol;
	skb_dst_drop(to);
	skb_dst_set(to, dst_clone(skb_dst(from)));
	to->dev = from->dev;
	to->mark = from->mark;

#ifdef CONFIG_NET_SCHED
	to->tc_index = from->tc_index;
#endif
	nf_copy(to, from);
	skb_copy_secmark(to, from);
}


Contributors
PersonTokensPropCommitsCommitProp
Kazunori Miyazawa7069.31%114.29%


Eric Dumazet87.92%114.29%


Thomas Graf87.92%114.29%


James Morris76.93%114.29%


Yasuyuki Kozakai43.96%228.57%


Hideaki Yoshifuji / 吉藤英明43.96%114.29%


Total101100.00%7100.00%






int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
		 int (*output)(struct net *, struct sock *, struct sk_buff *))
{
	struct sk_buff *frag;
	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
	struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
				inet6_sk(skb->sk) : NULL;
	struct ipv6hdr *tmp_hdr;
	struct frag_hdr *fh;
	unsigned int mtu, hlen, left, len;
	int hroom, troom;
	__be32 frag_id;
	int ptr, offset = 0, err = 0;
	u8 *prevhdr, nexthdr = 0;

	hlen = ip6_find_1stfragopt(skb, &prevhdr);
	nexthdr = *prevhdr;

	mtu = ip6_skb_dst_mtu(skb);

	/* We must not fragment if the socket is set to force MTU discovery
         * or if the skb it not generated by a local socket.
         */
	if (unlikely(!skb->ignore_df && skb->len > mtu))
		goto fail_toobig;

	if (IP6CB(skb)->frag_max_size) {
		if (IP6CB(skb)->frag_max_size > mtu)
			goto fail_toobig;

		/* don't send fragments larger than what we received */
		mtu = IP6CB(skb)->frag_max_size;
		if (mtu < IPV6_MIN_MTU)
			mtu = IPV6_MIN_MTU;
	}

	if (np && np->frag_size < mtu) {
		if (np->frag_size)
			mtu = np->frag_size;
	}
	if (mtu < hlen + sizeof(struct frag_hdr) + 8)
		goto fail_toobig;
	mtu -= hlen + sizeof(struct frag_hdr);

	frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
				    &ipv6_hdr(skb)->saddr);

	if (skb->ip_summed == CHECKSUM_PARTIAL &&
	    (err = skb_checksum_help(skb)))
		goto fail;

	hroom = LL_RESERVED_SPACE(rt->dst.dev);
	if (skb_has_frag_list(skb)) {
		unsigned int first_len = skb_pagelen(skb);
		struct sk_buff *frag2;

		if (first_len - hlen > mtu ||
		    ((first_len - hlen) & 7) ||
		    skb_cloned