C++ dev_get_by_index_rcu函数代码示例

int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
			  struct fib_lookup_arg *arg)
{
	struct net_device *dev;
	int rc = 0;

	rcu_read_lock();

	dev = dev_get_by_index_rcu(net, fl->flowi_oif);
	if (dev && netif_is_l3_master(dev) &&
	    dev->l3mdev_ops->l3mdev_fib_table) {
		arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
		rc = 1;
		goto out;
	}

	dev = dev_get_by_index_rcu(net, fl->flowi_iif);
	if (dev && netif_is_l3_master(dev) &&
	    dev->l3mdev_ops->l3mdev_fib_table) {
		arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
		rc = 1;
		goto out;
	}

out:
	rcu_read_unlock();

	return rc;
}

void l3mdev_update_flow(struct net *net, struct flowi *fl)
{
	struct net_device *dev;
	int ifindex;

	rcu_read_lock();

	if (fl->flowi_oif) {
		dev = dev_get_by_index_rcu(net, fl->flowi_oif);
		if (dev) {
			ifindex = l3mdev_master_ifindex_rcu(dev);
			if (ifindex) {
				fl->flowi_oif = ifindex;
				fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
				goto out;
			}
		}
	}

	if (fl->flowi_iif) {
		dev = dev_get_by_index_rcu(net, fl->flowi_iif);
		if (dev) {
			ifindex = l3mdev_master_ifindex_rcu(dev);
			if (ifindex) {
				fl->flowi_iif = ifindex;
				fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
			}
		}
	}

out:
	rcu_read_unlock();
}

/*
 *	socket leave an anycast group
 */
int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev;
	struct ipv6_ac_socklist *pac, *prev_pac;
	struct net *net = sock_net(sk);

	write_lock_bh(&ipv6_sk_ac_lock);
	prev_pac = NULL;
	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
		if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
		     ipv6_addr_equal(&pac->acl_addr, addr))
			break;
		prev_pac = pac;
	}
	if (!pac) {
		write_unlock_bh(&ipv6_sk_ac_lock);
		return -ENOENT;
	}
	if (prev_pac)
		prev_pac->acl_next = pac->acl_next;
	else
		np->ipv6_ac_list = pac->acl_next;

	write_unlock_bh(&ipv6_sk_ac_lock);

	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
	if (dev)
		ipv6_dev_ac_dec(dev, &pac->acl_addr);
	rcu_read_unlock();

	sock_kfree_s(sk, pac, sizeof(*pac));
	return 0;
}

void ipv6_sock_ac_close(struct sock *sk)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev = NULL;
	struct ipv6_ac_socklist *pac;
	struct net *net = sock_net(sk);
	int	prev_index;

	write_lock_bh(&ipv6_sk_ac_lock);
	pac = np->ipv6_ac_list;
	np->ipv6_ac_list = NULL;
	write_unlock_bh(&ipv6_sk_ac_lock);

	prev_index = 0;
	rcu_read_lock();
	while (pac) {
		struct ipv6_ac_socklist *next = pac->acl_next;

		if (pac->acl_ifindex != prev_index) {
			dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
			prev_index = pac->acl_ifindex;
		}
		if (dev)
			ipv6_dev_ac_dec(dev, &pac->acl_addr);
		sock_kfree_s(sk, pac, sizeof(*pac));
		pac = next;
	}
	rcu_read_unlock();
}

/*
 * Oops, a fragment queue timed out.  Kill it and send an ICMP reply.
 */
static void ip_expire(unsigned long arg)
{
	struct ipq *qp;
	struct net *net;

	qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
	net = container_of(qp->q.net, struct net, ipv4.frags);

	spin_lock(&qp->q.lock);

	if (qp->q.flags & INET_FRAG_COMPLETE)
		goto out;

	ipq_kill(qp);
	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);

	if (!(qp->q.flags & INET_FRAG_EVICTED)) {
		struct sk_buff *head = qp->q.fragments;
		const struct iphdr *iph;
		int err;

		IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT);

		if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !qp->q.fragments)
			goto out;

		rcu_read_lock();
		head->dev = dev_get_by_index_rcu(net, qp->iif);
		if (!head->dev)
			goto out_rcu_unlock;

		/* skb has no dst, perform route lookup again */
		iph = ip_hdr(head);
		err = ip_route_input_noref(head, iph->daddr, iph->saddr,
					   iph->tos, head->dev);
		if (err)
			goto out_rcu_unlock;

		/* Only an end host needs to send an ICMP
		 * "Fragment Reassembly Timeout" message, per RFC792.
		 */
		if (qp->user == IP_DEFRAG_AF_PACKET ||
		    ((qp->user >= IP_DEFRAG_CONNTRACK_IN) &&
		     (qp->user <= __IP_DEFRAG_CONNTRACK_IN_END) &&
		     (skb_rtable(head)->rt_type != RTN_LOCAL)))
			goto out_rcu_unlock;

		/* Send an ICMP "Fragment Reassembly Timeout" message. */
		icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
out_rcu_unlock:
		rcu_read_unlock();
	}
out:
	spin_unlock(&qp->q.lock);
	ipq_put(qp);
}

static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
			  struct tcf_pkt_info *info)
{
	struct ip_set_adt_opt opt;
	struct xt_action_param acpar;
	const struct xt_set_info *set = (const void *) em->data;
	struct net_device *dev, *indev = NULL;
	int ret, network_offset;

	switch (tc_skb_protocol(skb)) {
	case htons(ETH_P_IP):
		acpar.family = NFPROTO_IPV4;
		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
			return 0;
		acpar.thoff = ip_hdrlen(skb);
		break;
	case htons(ETH_P_IPV6):
		acpar.family = NFPROTO_IPV6;
		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
			return 0;
		/* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
		acpar.thoff = sizeof(struct ipv6hdr);
		break;
	default:
		return 0;
	}

	acpar.hooknum = 0;

	opt.family = acpar.family;
	opt.dim = set->dim;
	opt.flags = set->flags;
	opt.cmdflags = 0;
	opt.ext.timeout = ~0u;

	network_offset = skb_network_offset(skb);
	skb_pull(skb, network_offset);

	dev = skb->dev;

	rcu_read_lock();

	if (skb->skb_iif)
		indev = dev_get_by_index_rcu(em->net, skb->skb_iif);

	acpar.in      = indev ? indev : dev;
	acpar.out     = dev;

	ret = ip_set_test(set->index, skb, &acpar, &opt);

	rcu_read_unlock();

	skb_push(skb, network_offset);
	return ret;
}

/*
 * Oops, a fragment queue timed out.  Kill it and send an ICMP reply.
 */
static void ip_expire(unsigned long arg)
{
	struct ipq *qp;
	struct net *net;

	qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
	net = container_of(qp->q.net, struct net, ipv4.frags);

	spin_lock(&qp->q.lock);

	if (qp->q.last_in & INET_FRAG_COMPLETE)
		goto out;

	ipq_kill(qp);

	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT);
	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);

	if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) {
		struct sk_buff *head = qp->q.fragments;

		rcu_read_lock();
		head->dev = dev_get_by_index_rcu(net, qp->iif);
		if (!head->dev)
			goto out_rcu_unlock;

		/*
		 * Only search router table for the head fragment,
		 * when defraging timeout at PRE_ROUTING HOOK.
		 */
		if (qp->user == IP_DEFRAG_CONNTRACK_IN && !skb_dst(head)) {
			const struct iphdr *iph = ip_hdr(head);
			int err = ip_route_input(head, iph->daddr, iph->saddr,
						 iph->tos, head->dev);
			if (unlikely(err))
				goto out_rcu_unlock;

			/*
			 * Only an end host needs to send an ICMP
			 * "Fragment Reassembly Timeout" message, per RFC792.
			 */
			if (skb_rtable(head)->rt_type != RTN_LOCAL)
				goto out_rcu_unlock;

		}

		/* Send an ICMP "Fragment Reassembly Timeout" message. */
		icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
out_rcu_unlock:
		rcu_read_unlock();
	}
out:
	spin_unlock(&qp->q.lock);
	ipq_put(qp);
}

static int get_netdev_from_ifindex(struct net *net, int if_index,
				   struct ib_gid_attr *gid_attr_val)
{
	if (if_index && net) {
		rcu_read_lock();
		gid_attr_val->ndev = dev_get_by_index_rcu(net, if_index);
		rcu_read_unlock();
		if (gid_attr_val->ndev)
			return GID_ATTR_FIND_MASK_NETDEV;
	}
	return 0;
}

/* Caller must hold RCU or RTNL :
 * We dont take a reference on found in_device
 */
struct in_device *inetdev_by_index(struct net *net, int ifindex)
{
	struct net_device *dev;
	struct in_device *in_dev = NULL;

	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
	if (dev)
		in_dev = rcu_dereference_rtnl(dev->ip_ptr);
	rcu_read_unlock();
	return in_dev;
}

unsigned int
nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
			  const struct nf_hook_state *state)
{
	struct flow_offload_tuple_rhash *tuplehash;
	struct nf_flowtable *flow_table = priv;
	struct flow_offload_tuple tuple = {};
	enum flow_offload_tuple_dir dir;
	struct flow_offload *flow;
	struct net_device *outdev;
	struct in6_addr *nexthop;
	struct ipv6hdr *ip6h;
	struct rt6_info *rt;

	if (skb->protocol != htons(ETH_P_IPV6))
		return NF_ACCEPT;

	if (nf_flow_tuple_ipv6(skb, state->in, &tuple) < 0)
		return NF_ACCEPT;

	tuplehash = flow_offload_lookup(flow_table, &tuple);
	if (tuplehash == NULL)
		return NF_ACCEPT;

	outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.oifidx);
	if (!outdev)
		return NF_ACCEPT;

	dir = tuplehash->tuple.dir;
	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);

	rt = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache;
	if (unlikely(nf_flow_exceeds_mtu(skb, rt)))
		return NF_ACCEPT;

	if (skb_try_make_writable(skb, sizeof(*ip6h)))
		return NF_DROP;

	if (flow->flags & (FLOW_OFFLOAD_SNAT | FLOW_OFFLOAD_DNAT) &&
	    nf_flow_nat_ipv6(flow, skb, dir) < 0)
		return NF_DROP;

	flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT;
	ip6h = ipv6_hdr(skb);
	ip6h->hop_limit--;

	skb->dev = outdev;
	nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
	neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);

	return NF_STOLEN;
}

int
pfq_dev_refcnt_read_by_index(struct net *net, int ifindex)
{
	struct net_device *dev;
	int ref = -1;
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
	if (dev) {
		ref = netdev_refcnt_read(dev);
	}
	rcu_read_unlock();
	return ref;
}

u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
{
	struct net_device *dev;
	u32 tb_id = 0;

	if (!ifindex)
		return 0;

	rcu_read_lock();

	dev = dev_get_by_index_rcu(net, ifindex);
	if (dev)
		tb_id = l3mdev_fib_table_rcu(dev);

	rcu_read_unlock();

	return tb_id;
}

static void ip6_frag_expire(unsigned long data)
{
	struct frag_queue *fq;
	struct net_device *dev = NULL;
	struct net *net;

	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);

	spin_lock(&fq->q.lock);

	if (fq->q.last_in & INET_FRAG_COMPLETE)
		goto out;

	fq_kill(fq);

	net = container_of(fq->q.net, struct net, ipv6.frags);
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, fq->iif);
	if (!dev)
		goto out_rcu_unlock;

	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);

	/* Don't send error if the first segment did not arrive. */
	if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
		goto out_rcu_unlock;

	/*
	   But use as source device on which LAST ARRIVED
	   segment was received. And do not use fq->dev
	   pointer directly, device might already disappeared.
	 */
	fq->q.fragments->dev = dev;
	icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
out_rcu_unlock:
	rcu_read_unlock();
out:
	spin_unlock(&fq->q.lock);
	fq_put(fq);
}

void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
			   struct inet_frags *frags)
{
	struct net_device *dev = NULL;

	spin_lock(&fq->q.lock);

	if (fq->q.flags & INET_FRAG_COMPLETE)
		goto out;

	inet_frag_kill(&fq->q, frags);

	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, fq->iif);
	if (!dev)
		goto out_rcu_unlock;

	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);

	if (inet_frag_evicting(&fq->q))
		goto out_rcu_unlock;

	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);

	/* Don't send error if the first segment did not arrive. */
	if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments)
		goto out_rcu_unlock;

	/* But use as source device on which LAST ARRIVED
	 * segment was received. And do not use fq->dev
	 * pointer directly, device might already disappeared.
	 */
	fq->q.fragments->dev = dev;
	icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
out_rcu_unlock:
	rcu_read_unlock();
out:
	spin_unlock(&fq->q.lock);
	inet_frag_put(&fq->q, frags);
}

struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
					   struct flowi6 *fl6)
{
	struct dst_entry *dst = NULL;
	struct net_device *dev;

	if (fl6->flowi6_oif) {
		rcu_read_lock();

		dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
		if (dev && netif_is_l3_slave(dev))
			dev = netdev_master_upper_dev_get_rcu(dev);

		if (dev && netif_is_l3_master(dev) &&
		    dev->l3mdev_ops->l3mdev_link_scope_lookup)
			dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6);

		rcu_read_unlock();
	}

	return dst;
}