C++ dev_get_by_index函数代码示例

static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
{
	struct ip6_tnl_parm *p = &t->parms;
	int ret = 0;

	if (p->flags & IP6_TNL_F_CAP_XMIT) {
		struct net_device *ldev = NULL;

		if (p->link)
			ldev = dev_get_by_index(p->link);

		if (unlikely(!ipv6_chk_addr(&p->laddr, ldev, 0)))
			printk(KERN_WARNING
			       "%s xmit: Local address not yet configured!\n",
			       p->name);
		else if (!ipv6_addr_is_multicast(&p->raddr) &&
			 unlikely(ipv6_chk_addr(&p->raddr, NULL, 0)))
			printk(KERN_WARNING
			       "%s xmit: Routing loop! "
			       "Remote address found on this node!\n",
			       p->name);
		else
			ret = 1;
		if (ldev)
			dev_put(ldev);
	}
	return ret;
}

static int ipip_tunnel_init(struct device *dev)
{
	struct device *tdev = NULL;
	struct ip_tunnel *tunnel;
	struct iphdr *iph;

	tunnel = (struct ip_tunnel*)dev->priv;
	iph = &tunnel->parms.iph;

	ipip_tunnel_init_gen(dev);

	if (iph->daddr) {
		struct rtable *rt;
		if (!ip_route_output(&rt, iph->daddr, iph->saddr, RT_TOS(iph->tos), tunnel->parms.link)) {
			tdev = rt->u.dst.dev;
			ip_rt_put(rt);
		}
		dev->flags |= IFF_POINTOPOINT;
	}

	if (!tdev && tunnel->parms.link)
		tdev = dev_get_by_index(tunnel->parms.link);

	if (tdev) {
		dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
		dev->mtu = tdev->mtu - sizeof(struct iphdr);
	}
	dev->iflink = tunnel->parms.link;

	return 0;
}

static void ip6_frag_expire(unsigned long data)
{
	struct frag_queue *fq = (struct frag_queue *) data;

	spin_lock(&fq->lock);

	if (fq->last_in & COMPLETE)
		goto out;

	fq_kill(fq);

	IP6_INC_STATS_BH(Ip6ReasmTimeout);
	IP6_INC_STATS_BH(Ip6ReasmFails);

	/* Send error only if the first segment arrived. */
	if (fq->last_in&FIRST_IN && fq->fragments) {
		struct net_device *dev = dev_get_by_index(fq->iif);

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

static inline
bool copy_to_dev_skbs(struct pfq_sock *so, struct gc_queue_buff *queue, unsigned long long mask, int cpu, int gid)
{
	if (so->egress_index) {

		struct net_device *dev;
		bool ret;

               	dev = dev_get_by_index(&init_net, so->egress_index);

               	if (dev == NULL)
		{
			if (printk_ratelimit()) {
                        	printk(KERN_INFO "[PFQ] egress endpoint index (%d)\n", so->egress_index);
                        	return false;
			}
		}

 		ret = pfq_lazy_queue_xmit_by_mask(queue, mask, dev, so->egress_queue);

                dev_put(dev);

		return ret != 0;
	}

	return false;
}

static int raw_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct raw_opt *ro = raw_sk(sk);
	struct net_device *dev = NULL;

	DBG("socket %p, sk %p, refcnt %d\n", sock, sk,
	    atomic_read(&sk->sk_refcnt));

	if (ro->bound && ro->ifindex)
		dev = dev_get_by_index(ro->ifindex);

	/* remove current filters & unregister */
	if (ro->bound)
		raw_remove_filters(dev, sk);

	if (ro->count > 1)
		kfree(ro->filter);

	/* remove current error mask */
	if (ro->err_mask && ro->bound)
		can_rx_unregister(dev, 0, ro->err_mask | CAN_ERR_FLAG,
				  raw_rcv, sk);

	if (dev) {
		can_dev_unregister(dev, raw_notifier, sk);
		dev_put(dev);
	}

	sock_put(sk);

	return 0;
}

/* Requests from userspace */
static struct net_device *ieee802154_nl_get_dev(struct genl_info *info)
{
	struct net_device *dev;

	if (info->attrs[IEEE802154_ATTR_DEV_NAME]) {
		char name[IFNAMSIZ + 1];

		nla_strlcpy(name, info->attrs[IEEE802154_ATTR_DEV_NAME],
			    sizeof(name));
		dev = dev_get_by_name(&init_net, name);
	} else if (info->attrs[IEEE802154_ATTR_DEV_INDEX]) {
		dev = dev_get_by_index(&init_net,
			nla_get_u32(info->attrs[IEEE802154_ATTR_DEV_INDEX]));
	} else {
		return NULL;
	}

	if (!dev)
		return NULL;

	/* Check on mtu is currently a hacked solution because lowpan
	 * and wpan have the same ARPHRD type.
	 */
	if (dev->type != ARPHRD_IEEE802154 || dev->mtu != IEEE802154_MTU) {
		dev_put(dev);
		return NULL;
	}

	return dev;
}

static void netlink_rcv_cb(struct sk_buff *skb)
{
	struct nlmsghdr *nlh;
	struct net_device *dev;
	u32 mlen;
	void *msg;
	int ifindex;

	if (skb->len >= NLMSG_SPACE(0)) {
		nlh = (struct nlmsghdr *)skb->data;

		if (skb->len < nlh->nlmsg_len ||
		nlh->nlmsg_len > ND_MAX_MSG_LEN) {
			printk(KERN_ERR "Invalid length (%d,%d)\n", skb->len,
				nlh->nlmsg_len);
			return;
		}

		memcpy(&ifindex, ND_NLMSG_IFIDX(nlh), ND_IFINDEX_LEN);
		msg = ND_NLMSG_DATA(nlh);
		mlen = ND_NLMSG_R_LEN(nlh);

		if (rcv_cb) {
			dev = dev_get_by_index(&init_net, ifindex);
			if (dev) {
				rcv_cb(dev, nlh->nlmsg_type, msg, mlen);
				dev_put(dev);
			} else
				printk(KERN_ERR "dev_get_by_index(%d) "
					"is not found.\n", ifindex);
		} else
			printk(KERN_ERR "Unregistered Callback\n");
	}
}

bool copy_to_endpoint_skbs(struct pfq_sock *so, struct pfq_non_intrusive_skb *skbs, unsigned long long skbs_mask, int cpu, int gid)
{
	if (so->egress_index) {

		struct net_device *dev;
		struct sk_buff *skb;
		bool ret;
		int n;

                pfq_non_intrusive_for_each(skb, n, skbs)
		{
 			atomic_inc(&skb->users);
               	}

               	dev = dev_get_by_index(&init_net, so->egress_index);
               	if (dev == NULL)
		{
			if (printk_ratelimit()) {
                        	printk(KERN_INFO "[PFQ] egress endpoint index (%d)\n", so->egress_index);
                        	return false;
			}
		}

 		ret = pfq_queue_xmit_by_mask(skbs, skbs_mask, dev, so->egress_queue);
                dev_put(dev);
		return ret;
	}

static int raw_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);

	unregister_netdevice_notifier(&ro->notifier);

	lock_sock(sk);

	/* remove current filters & unregister */
	if (ro->bound) {
		if (ro->ifindex) {
			struct net_device *dev;

			dev = dev_get_by_index(&init_net, ro->ifindex);
			if (dev) {
				raw_disable_allfilters(dev, sk);
				dev_put(dev);
			}
		} else
			raw_disable_allfilters(NULL, sk);
	}

	if (ro->count > 1)
		kfree(ro->filter);

	ro->ifindex = 0;
	ro->bound   = 0;
	ro->count   = 0;

	release_sock(sk);
	sock_put(sk);

	return 0;
}

/*
 *	socket leave on multicast group
 */
int ipv6_sock_mc_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
{
	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
	struct ipv6_mc_socklist *mc_lst, **lnk;

	write_lock_bh(&ipv6_sk_mc_lock);
	for (lnk = &np->ipv6_mc_list; (mc_lst = *lnk) !=NULL ; lnk = &mc_lst->next) {
		if (mc_lst->ifindex == ifindex &&
		    ipv6_addr_cmp(&mc_lst->addr, addr) == 0) {
			struct net_device *dev;

			*lnk = mc_lst->next;
			write_unlock_bh(&ipv6_sk_mc_lock);

			if ((dev = dev_get_by_index(ifindex)) != NULL) {
				ipv6_dev_mc_dec(dev, &mc_lst->addr);
				dev_put(dev);
			}
			sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
			return 0;
		}
	}
	write_unlock_bh(&ipv6_sk_mc_lock);

	return -ENOENT;
}

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

		if (pac->acl_ifindex != prev_index) {
			if (dev)
				dev_put(dev);
			dev = dev_get_by_index(&init_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;
	}
	if (dev)
		dev_put(dev);
}

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

	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);

	dev = dev_get_by_index(&init_net, pac->acl_ifindex);
	if (dev) {
		ipv6_dev_ac_dec(dev, &pac->acl_addr);
		dev_put(dev);
	}
	sock_kfree_s(sk, pac, sizeof(*pac));
	return 0;
}

/* Requests from userspace */
static struct net_device *ieee802154_nl_get_dev(struct genl_info *info)
{
	struct net_device *dev;

	if (info->attrs[IEEE802154_ATTR_DEV_NAME]) {
		char name[IFNAMSIZ + 1];
		nla_strlcpy(name, info->attrs[IEEE802154_ATTR_DEV_NAME],
				sizeof(name));
		dev = dev_get_by_name(&init_net, name);
	} else if (info->attrs[IEEE802154_ATTR_DEV_INDEX])
		dev = dev_get_by_index(&init_net,
			nla_get_u32(info->attrs[IEEE802154_ATTR_DEV_INDEX]));
	else
		return NULL;

	if (!dev)
		return NULL;

	if (dev->type != ARPHRD_IEEE802154) {
		dev_put(dev);
		return NULL;
	}

	return dev;
}

/*
 * Create a Phonet header for the skb and send it out. Returns
 * non-zero error code if failed. The skb is freed then.
 */
int pn_skb_send(struct sock *sk, struct sk_buff *skb,
		const struct sockaddr_pn *target)
{
	struct net *net = sock_net(sk);
	struct net_device *dev;
	struct pn_sock *pn = pn_sk(sk);
	int err;
	u16 src, dst;
	u8 daddr, saddr, res;

	src = pn->sobject;
	if (target != NULL) {
		dst = pn_sockaddr_get_object(target);
		res = pn_sockaddr_get_resource(target);
	} else {
		dst = pn->dobject;
		res = pn->resource;
	}
	daddr = pn_addr(dst);

	err = -EHOSTUNREACH;
	if (sk->sk_bound_dev_if)
		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
	else if (phonet_address_lookup(net, daddr) == 0) {
		dev = phonet_device_get(net);
		skb->pkt_type = PACKET_LOOPBACK;
	} else if (dst == 0) {
		/* Resource routing (small race until phonet_rcv()) */
		struct sock *sk = pn_find_sock_by_res(net, res);
		if (sk)	{
			sock_put(sk);
			dev = phonet_device_get(net);
			skb->pkt_type = PACKET_LOOPBACK;
		} else
			dev = phonet_route_output(net, daddr);
	} else
		dev = phonet_route_output(net, daddr);

	if (!dev || !(dev->flags & IFF_UP))
		goto drop;

	saddr = phonet_address_get(dev, daddr);
	if (saddr == PN_NO_ADDR)
		goto drop;

	if (!pn_addr(src))
		src = pn_object(saddr, pn_obj(src));

	err = pn_send(skb, dev, dst, src, res, 0);
	dev_put(dev);
	return err;

drop:
	printk(KERN_DEBUG "pn_skb_send DROP\n");
	kfree_skb(skb);
	if (dev)
		dev_put(dev);
	return err;
}

static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
		       struct msghdr *msg, size_t size)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	struct sk_buff *skb;
	struct net_device *dev;
	int ifindex;
	int err;

	if (msg->msg_name) {
		struct sockaddr_can *addr =
			(struct sockaddr_can *)msg->msg_name;

		if (addr->can_family != AF_CAN)
			return -EINVAL;

		ifindex = addr->can_ifindex;
	} else
		ifindex = ro->ifindex;

	if (size != sizeof(struct can_frame))
		return -EINVAL;

	dev = dev_get_by_index(&init_net, ifindex);
	if (!dev)
		return -ENXIO;

	skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
				  &err);
	if (!skb)
		goto put_dev;

	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
	if (err < 0)
		goto free_skb;
	err = sock_tx_timestamp(msg, sk, skb_tx(skb));
	if (err < 0)
		goto free_skb;
	skb->dev = dev;
	skb->sk  = sk;

	err = can_send(skb, ro->loopback);

	dev_put(dev);

	if (err)
		goto send_failed;

	return size;

free_skb:
	kfree_skb(skb);
put_dev:
	dev_put(dev);
send_failed:
	return err;
}