Commit message: net/packet: fix overflow in check for tp_reserve

When calculating po->tp_hdrlen + po->tp_reserve the result can overflow.

Fix by checking that tp_reserve <= INT_MAX on assign.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: CVE-2017-7308
CWE: CWE-119
Vulnerability description: The packet_set_ring function in net/packet/af_packet.c in the Linux kernel through 4.10.6 does not properly validate certain block-size data, which allows local users to cause a denial of service (integer signedness error and out-of-bounds write), or gain privileges (if the CAP_NET_RAW capability is held), via crafted system calls.

Project: linux
File: af_packet.c

static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
		int closing, int tx_ring)
{
	struct pgv *pg_vec = NULL;
	struct packet_sock *po = pkt_sk(sk);
	int was_running, order = 0;
	struct packet_ring_buffer *rb;
	struct sk_buff_head *rb_queue;
	__be16 num;
	int err = -EINVAL;
	/* Added to avoid minimal code churn */
	struct tpacket_req *req = &req_u->req;

	lock_sock(sk);

	rb = tx_ring ? &po->tx_ring : &po->rx_ring;
	rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;

	err = -EBUSY;
	if (!closing) {
		if (atomic_read(&po->mapped))
			goto out;
		if (packet_read_pending(rb))
			goto out;
	}

	if (req->tp_block_nr) {
		/* Sanity tests and some calculations */
		err = -EBUSY;
		if (unlikely(rb->pg_vec))
			goto out;

		switch (po->tp_version) {
		case TPACKET_V1:
			po->tp_hdrlen = TPACKET_HDRLEN;
			break;
		case TPACKET_V2:
			po->tp_hdrlen = TPACKET2_HDRLEN;
			break;
		case TPACKET_V3:
			po->tp_hdrlen = TPACKET3_HDRLEN;
			break;
		}

		err = -EINVAL;
		if (unlikely((int)req->tp_block_size <= 0))
			goto out;
		if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
			goto out;
		if (po->tp_version >= TPACKET_V3 &&
		    req->tp_block_size <=
			  BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
			goto out;
		if (unlikely(req->tp_frame_size < po->tp_hdrlen +
					po->tp_reserve))
			goto out;
		if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
			goto out;

		rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
		if (unlikely(rb->frames_per_block == 0))
			goto out;
		if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
			goto out;
		if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
					req->tp_frame_nr))
			goto out;

		err = -ENOMEM;
		order = get_order(req->tp_block_size);
		pg_vec = alloc_pg_vec(req, order);
		if (unlikely(!pg_vec))
			goto out;
		switch (po->tp_version) {
		case TPACKET_V3:
			/* Block transmit is not supported yet */
			if (!tx_ring) {
				init_prb_bdqc(po, rb, pg_vec, req_u);
			} else {
				struct tpacket_req3 *req3 = &req_u->req3;

				if (req3->tp_retire_blk_tov ||
				    req3->tp_sizeof_priv ||
				    req3->tp_feature_req_word) {
					err = -EINVAL;
					goto out;
				}
			}
			break;
		default:
			break;
		}
	}
	/* Done */
	else {
		err = -EINVAL;
		if (unlikely(req->tp_frame_nr))
			goto out;
	}


	/* Detach socket from network */
	spin_lock(&po->bind_lock);
	was_running = po->running;
	num = po->num;
	if (was_running) {
		po->num = 0;
		__unregister_prot_hook(sk, false);
	}
	spin_unlock(&po->bind_lock);

	synchronize_net();

	err = -EBUSY;
	mutex_lock(&po->pg_vec_lock);
	if (closing || atomic_read(&po->mapped) == 0) {
		err = 0;
		spin_lock_bh(&rb_queue->lock);
		swap(rb->pg_vec, pg_vec);
		rb->frame_max = (req->tp_frame_nr - 1);
		rb->head = 0;
		rb->frame_size = req->tp_frame_size;
		spin_unlock_bh(&rb_queue->lock);

		swap(rb->pg_vec_order, order);
		swap(rb->pg_vec_len, req->tp_block_nr);

		rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
		po->prot_hook.func = (po->rx_ring.pg_vec) ?
						tpacket_rcv : packet_rcv;
		skb_queue_purge(rb_queue);
		if (atomic_read(&po->mapped))
			pr_err("packet_mmap: vma is busy: %d\n",
			       atomic_read(&po->mapped));
	}
	mutex_unlock(&po->pg_vec_lock);

	spin_lock(&po->bind_lock);
	if (was_running) {
		po->num = num;
		register_prot_hook(sk);
	}
	spin_unlock(&po->bind_lock);
	if (closing && (po->tp_version > TPACKET_V2)) {
		/* Because we don't support block-based V3 on tx-ring */
		if (!tx_ring)
			prb_shutdown_retire_blk_timer(po, rb_queue);
	}

	if (pg_vec)
		free_pg_vec(pg_vec, order, req->tp_block_nr);
out:
	release_sock(sk);
	return err;
}

Project: linux
File: af_packet.c

static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct net *net = seq_file_net(seq);
	return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
}

Project: linux
File: af_packet.c

static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
{
	struct packet_rollover *rollover = NULL;
	struct packet_sock *po = pkt_sk(sk);
	struct packet_fanout *f, *match;
	u8 type = type_flags & 0xff;
	u8 flags = type_flags >> 8;
	int err;

	switch (type) {
	case PACKET_FANOUT_ROLLOVER:
		if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
			return -EINVAL;
	case PACKET_FANOUT_HASH:
	case PACKET_FANOUT_LB:
	case PACKET_FANOUT_CPU:
	case PACKET_FANOUT_RND:
	case PACKET_FANOUT_QM:
	case PACKET_FANOUT_CBPF:
	case PACKET_FANOUT_EBPF:
		break;
	default:
		return -EINVAL;
	}

	mutex_lock(&fanout_mutex);

	err = -EINVAL;
	if (!po->running)
		goto out;

	err = -EALREADY;
	if (po->fanout)
		goto out;

	if (type == PACKET_FANOUT_ROLLOVER ||
	    (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
		err = -ENOMEM;
		rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
		if (!rollover)
			goto out;
		atomic_long_set(&rollover->num, 0);
		atomic_long_set(&rollover->num_huge, 0);
		atomic_long_set(&rollover->num_failed, 0);
		po->rollover = rollover;
	}

	match = NULL;
	list_for_each_entry(f, &fanout_list, list) {
		if (f->id == id &&
		    read_pnet(&f->net) == sock_net(sk)) {
			match = f;
			break;
		}
	}
	err = -EINVAL;
	if (match && match->flags != flags)
		goto out;
	if (!match) {
		err = -ENOMEM;
		match = kzalloc(sizeof(*match), GFP_KERNEL);
		if (!match)
			goto out;
		write_pnet(&match->net, sock_net(sk));
		match->id = id;
		match->type = type;
		match->flags = flags;
		INIT_LIST_HEAD(&match->list);
		spin_lock_init(&match->lock);
		atomic_set(&match->sk_ref, 0);
		fanout_init_data(match);
		match->prot_hook.type = po->prot_hook.type;
		match->prot_hook.dev = po->prot_hook.dev;
		match->prot_hook.func = packet_rcv_fanout;
		match->prot_hook.af_packet_priv = match;
		match->prot_hook.id_match = match_fanout_group;
		list_add(&match->list, &fanout_list);
	}
	err = -EINVAL;
	if (match->type == type &&
	    match->prot_hook.type == po->prot_hook.type &&
	    match->prot_hook.dev == po->prot_hook.dev) {
		err = -ENOSPC;
		if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
			__dev_remove_pack(&po->prot_hook);
			po->fanout = match;
			atomic_inc(&match->sk_ref);
			__fanout_link(sk, po);
			err = 0;
		}
	}
out:
	if (err && rollover) {
		kfree(rollover);
		po->rollover = NULL;
	}
	mutex_unlock(&fanout_mutex);
	return err;
}

Project: linux
File: af_packet.c

static int packet_ioctl(struct socket *sock, unsigned int cmd,
			unsigned long arg)
{
	struct sock *sk = sock->sk;

	switch (cmd) {
	case SIOCOUTQ:
	{
		int amount = sk_wmem_alloc_get(sk);

		return put_user(amount, (int __user *)arg);
	}
	case SIOCINQ:
	{
		struct sk_buff *skb;
		int amount = 0;

		spin_lock_bh(&sk->sk_receive_queue.lock);
		skb = skb_peek(&sk->sk_receive_queue);
		if (skb)
			amount = skb->len;
		spin_unlock_bh(&sk->sk_receive_queue.lock);
		return put_user(amount, (int __user *)arg);
	}
	case SIOCGSTAMP:
		return sock_get_timestamp(sk, (struct timeval __user *)arg);
	case SIOCGSTAMPNS:
		return sock_get_timestampns(sk, (struct timespec __user *)arg);

#ifdef CONFIG_INET
	case SIOCADDRT:
	case SIOCDELRT:
	case SIOCDARP:
	case SIOCGARP:
	case SIOCSARP:
	case SIOCGIFADDR:
	case SIOCSIFADDR:
	case SIOCGIFBRDADDR:
	case SIOCSIFBRDADDR:
	case SIOCGIFNETMASK:
	case SIOCSIFNETMASK:
	case SIOCGIFDSTADDR:
	case SIOCSIFDSTADDR:
	case SIOCSIFFLAGS:
		return inet_dgram_ops.ioctl(sock, cmd, arg);
#endif

	default:
		return -ENOIOCTLCMD;
	}
	return 0;
}

Project: linux
File: af_packet.c

static void packet_mm_open(struct vm_area_struct *vma)
{
	struct file *file = vma->vm_file;
	struct socket *sock = file->private_data;
	struct sock *sk = sock->sk;

	if (sk)
		atomic_inc(&pkt_sk(sk)->mapped);
}

Project: linux
File: af_packet.c

static int __init packet_init(void)
{
	int rc = proto_register(&packet_proto, 0);

	if (rc != 0)
		goto out;

	sock_register(&packet_family_ops);
	register_pernet_subsys(&packet_net_ops);
	register_netdevice_notifier(&packet_netdev_notifier);
out:
	return rc;
}

Project: linux
File: af_packet.c

	__acquires(RCU)
{
	struct net *net = seq_file_net(seq);

	rcu_read_lock();
	return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
}

Project: linux
File: af_packet.c

static void *__packet_lookup_frame_in_block(struct packet_sock *po,
					    struct sk_buff *skb,
						int status,
					    unsigned int len
					    )
{
	struct tpacket_kbdq_core *pkc;
	struct tpacket_block_desc *pbd;
	char *curr, *end;

	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);

	/* Queue is frozen when user space is lagging behind */
	if (prb_queue_frozen(pkc)) {
		/*
		 * Check if that last block which caused the queue to freeze,
		 * is still in_use by user-space.
		 */
		if (prb_curr_blk_in_use(pkc, pbd)) {
			/* Can't record this packet */
			return NULL;
		} else {
			/*
			 * Ok, the block was released by user-space.
			 * Now let's open that block.
			 * opening a block also thaws the queue.
			 * Thawing is a side effect.
			 */
			prb_open_block(pkc, pbd);
		}
	}

	smp_mb();
	curr = pkc->nxt_offset;
	pkc->skb = skb;
	end = (char *)pbd + pkc->kblk_size;

	/* first try the current block */
	if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
		prb_fill_curr_block(curr, pkc, pbd, len);
		return (void *)curr;
	}

	/* Ok, close the current block */
	prb_retire_current_block(pkc, po, 0);

	/* Now, try to dispatch the next block */
	curr = (char *)prb_dispatch_next_block(pkc, po);
	if (curr) {
		pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
		prb_fill_curr_block(curr, pkc, pbd, len);
		return (void *)curr;
	}

	/*
	 * No free blocks are available.user_space hasn't caught up yet.
	 * Queue was just frozen and now this packet will get dropped.
	 */
	return NULL;
}

Project: linux
File: af_packet.c

static void packet_sock_destruct(struct sock *sk)
{
	skb_queue_purge(&sk->sk_error_queue);

	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
	WARN_ON(atomic_read(&sk->sk_wmem_alloc));

	if (!sock_flag(sk, SOCK_DEAD)) {
		pr_err("Attempt to release alive packet socket: %p\n", sk);
		return;
	}

	sk_refcnt_debug_dec(sk);
}

Project: linux
File: af_packet.c

static void prb_fill_curr_block(char *curr,
				struct tpacket_kbdq_core *pkc,
				struct tpacket_block_desc *pbd,
				unsigned int len)
{
	struct tpacket3_hdr *ppd;

	ppd  = (struct tpacket3_hdr *)curr;
	ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
	pkc->prev = curr;
	pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
	BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
	BLOCK_NUM_PKTS(pbd) += 1;
	atomic_inc(&pkc->blk_fill_in_prog);
	prb_run_all_ft_ops(pkc, ppd);
}

Project: linux
File: af_packet.c

static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
			       int *uaddr_len, int peer)
{
	struct net_device *dev;
	struct sock *sk	= sock->sk;

	if (peer)
		return -EOPNOTSUPP;

	uaddr->sa_family = AF_PACKET;
	memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
	rcu_read_lock();
	dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
	if (dev)
		strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
	rcu_read_unlock();
	*uaddr_len = sizeof(*uaddr);

	return 0;
}

Project: linux
File: af_packet.c

static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
{
	return f->flags & (flag >> 8);
}

Project: linux
File: af_packet.c

static void __exit packet_exit(void)
{
	unregister_netdevice_notifier(&packet_netdev_notifier);
	unregister_pernet_subsys(&packet_net_ops);
	sock_unregister(PF_PACKET);
	proto_unregister(&packet_proto);
}

Project: linux
File: af_packet.c

static struct packet_fanout *fanout_release(struct sock *sk)
{
	struct packet_sock *po = pkt_sk(sk);
	struct packet_fanout *f;

	mutex_lock(&fanout_mutex);
	f = po->fanout;
	if (f) {
		po->fanout = NULL;

		if (atomic_dec_and_test(&f->sk_ref))
			list_del(&f->list);
		else
			f = NULL;

		if (po->rollover)
			kfree_rcu(po->rollover, rcu);
	}
	mutex_unlock(&fanout_mutex);

	return f;
}

Project: linux
File: af_packet.c

static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
			   struct packet_type *pt, struct net_device *orig_dev)
{
	struct sock *sk;
	struct sockaddr_pkt *spkt;

	/*
	 *	When we registered the protocol we saved the socket in the data
	 *	field for just this event.
	 */

	sk = pt->af_packet_priv;

	/*
	 *	Yank back the headers [hope the device set this
	 *	right or kerboom...]
	 *
	 *	Incoming packets have ll header pulled,
	 *	push it back.
	 *
	 *	For outgoing ones skb->data == skb_mac_header(skb)
	 *	so that this procedure is noop.
	 */

	if (skb->pkt_type == PACKET_LOOPBACK)
		goto out;

	if (!net_eq(dev_net(dev), sock_net(sk)))
		goto out;

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (skb == NULL)
		goto oom;

	/* drop any routing info */
	skb_dst_drop(skb);

	/* drop conntrack reference */
	nf_reset(skb);

	spkt = &PACKET_SKB_CB(skb)->sa.pkt;

	skb_push(skb, skb->data - skb_mac_header(skb));

	/*
	 *	The SOCK_PACKET socket receives _all_ frames.
	 */

	spkt->spkt_family = dev->type;
	strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
	spkt->spkt_protocol = skb->protocol;

	/*
	 *	Charge the memory to the socket. This is done specifically
	 *	to prevent sockets using all the memory up.
	 */

	if (sock_queue_rcv_skb(sk, skb) == 0)
		return 0;

out:
	kfree_skb(skb);
oom:
	return 0;
}

Project: linux
File: af_packet.c

static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
{
	struct sk_buff *skb;
	struct net_device *dev;
	struct virtio_net_hdr *vnet_hdr = NULL;
	struct sockcm_cookie sockc;
	__be16 proto;
	int err, reserve = 0;
	void *ph;
	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
	bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
	int tp_len, size_max;
	unsigned char *addr;
	void *data;
	int len_sum = 0;
	int status = TP_STATUS_AVAILABLE;
	int hlen, tlen, copylen = 0;

	mutex_lock(&po->pg_vec_lock);

	if (likely(saddr == NULL)) {
		dev	= packet_cached_dev_get(po);
		proto	= po->num;
		addr	= NULL;
	} else {
		err = -EINVAL;
		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
			goto out;
		if (msg->msg_namelen < (saddr->sll_halen
					+ offsetof(struct sockaddr_ll,
						sll_addr)))
			goto out;
		proto	= saddr->sll_protocol;
		addr	= saddr->sll_addr;
		dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
	}

	sockc.tsflags = po->sk.sk_tsflags;
	if (msg->msg_controllen) {
		err = sock_cmsg_send(&po->sk, msg, &sockc);
		if (unlikely(err))
			goto out;
	}

	err = -ENXIO;
	if (unlikely(dev == NULL))
		goto out;
	err = -ENETDOWN;
	if (unlikely(!(dev->flags & IFF_UP)))
		goto out_put;

	if (po->sk.sk_socket->type == SOCK_RAW)
		reserve = dev->hard_header_len;
	size_max = po->tx_ring.frame_size
		- (po->tp_hdrlen - sizeof(struct sockaddr_ll));

	if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
		size_max = dev->mtu + reserve + VLAN_HLEN;

	do {
		ph = packet_current_frame(po, &po->tx_ring,
					  TP_STATUS_SEND_REQUEST);
		if (unlikely(ph == NULL)) {
			if (need_wait && need_resched())
				schedule();
			continue;
		}

		skb = NULL;
		tp_len = tpacket_parse_header(po, ph, size_max, &data);
		if (tp_len < 0)
			goto tpacket_error;

		status = TP_STATUS_SEND_REQUEST;
		hlen = LL_RESERVED_SPACE(dev);
		tlen = dev->needed_tailroom;
		if (po->has_vnet_hdr) {
			vnet_hdr = data;
			data += sizeof(*vnet_hdr);
			tp_len -= sizeof(*vnet_hdr);
			if (tp_len < 0 ||
			    __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
				tp_len = -EINVAL;
				goto tpacket_error;
			}
			copylen = __virtio16_to_cpu(vio_le(),
						    vnet_hdr->hdr_len);
		}
		copylen = max_t(int, copylen, dev->hard_header_len);
		skb = sock_alloc_send_skb(&po->sk,
				hlen + tlen + sizeof(struct sockaddr_ll) +
				(copylen - dev->hard_header_len),
				!need_wait, &err);

		if (unlikely(skb == NULL)) {
			/* we assume the socket was initially writeable ... */
			if (likely(len_sum > 0))
				err = len_sum;
			goto out_status;
		}
		tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
					  addr, hlen, copylen, &sockc);
		if (likely(tp_len >= 0) &&
		    tp_len > dev->mtu + reserve &&
		    !po->has_vnet_hdr &&
		    !packet_extra_vlan_len_allowed(dev, skb))
			tp_len = -EMSGSIZE;

		if (unlikely(tp_len < 0)) {
tpacket_error:
			if (po->tp_loss) {
				__packet_set_status(po, ph,
						TP_STATUS_AVAILABLE);
				packet_increment_head(&po->tx_ring);
				kfree_skb(skb);
				continue;
			} else {
				status = TP_STATUS_WRONG_FORMAT;
				err = tp_len;
				goto out_status;
			}
		}

		if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr,
							      vio_le())) {
			tp_len = -EINVAL;
			goto tpacket_error;
		}

		packet_pick_tx_queue(dev, skb);

		skb->destructor = tpacket_destruct_skb;
		__packet_set_status(po, ph, TP_STATUS_SENDING);
		packet_inc_pending(&po->tx_ring);

		status = TP_STATUS_SEND_REQUEST;
		err = po->xmit(skb);
		if (unlikely(err > 0)) {
			err = net_xmit_errno(err);
			if (err && __packet_get_status(po, ph) ==
				   TP_STATUS_AVAILABLE) {
				/* skb was destructed already */
				skb = NULL;
				goto out_status;
			}
			/*
			 * skb was dropped but not destructed yet;
			 * let's treat it like congestion or err < 0
			 */
			err = 0;
		}
		packet_increment_head(&po->tx_ring);
		len_sum += tp_len;
	} while (likely((ph != NULL) ||
		/* Note: packet_read_pending() might be slow if we have
		 * to call it as it's per_cpu variable, but in fast-path
		 * we already short-circuit the loop with the first
		 * condition, and luckily don't have to go that path
		 * anyway.
		 */
		 (need_wait && packet_read_pending(&po->tx_ring))));

	err = len_sum;
	goto out_put;

out_status:
	__packet_set_status(po, ph, status);
	kfree_skb(skb);
out_put:
	dev_put(dev);
out:
	mutex_unlock(&po->pg_vec_lock);
	return err;
}

Project: linux
File: af_packet.c

static void packet_mm_close(struct vm_area_struct *vma)
{
	struct file *file = vma->vm_file;
	struct socket *sock = file->private_data;
	struct sock *sk = sock->sk;

	if (sk)
		atomic_dec(&pkt_sk(sk)->mapped);
}

Project: linux
File: af_packet.c

static int packet_mmap(struct file *file, struct socket *sock,
		struct vm_area_struct *vma)
{
	struct sock *sk = sock->sk;
	struct packet_sock *po = pkt_sk(sk);
	unsigned long size, expected_size;
	struct packet_ring_buffer *rb;
	unsigned long start;
	int err = -EINVAL;
	int i;

	if (vma->vm_pgoff)
		return -EINVAL;

	mutex_lock(&po->pg_vec_lock);

	expected_size = 0;
	for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
		if (rb->pg_vec) {
			expected_size += rb->pg_vec_len
						* rb->pg_vec_pages
						* PAGE_SIZE;
		}
	}

	if (expected_size == 0)
		goto out;

	size = vma->vm_end - vma->vm_start;
	if (size != expected_size)
		goto out;

	start = vma->vm_start;
	for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
		if (rb->pg_vec == NULL)
			continue;

		for (i = 0; i < rb->pg_vec_len; i++) {
			struct page *page;
			void *kaddr = rb->pg_vec[i].buffer;
			int pg_num;

			for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
				page = pgv_to_page(kaddr);
				err = vm_insert_page(vma, start, page);
				if (unlikely(err))
					goto out;
				start += PAGE_SIZE;
				kaddr += PAGE_SIZE;
			}
		}
	}

	atomic_inc(&po->mapped);
	vma->vm_ops = &packet_mmap_ops;
	err = 0;

out:
	mutex_unlock(&po->pg_vec_lock);
	return err;
}

Project: linux
File: af_packet.c

packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
{
	struct sock *sk = sock->sk;
	struct packet_sock *po = pkt_sk(sk);
	int ret;

	if (level != SOL_PACKET)
		return -ENOPROTOOPT;

	switch (optname) {
	case PACKET_ADD_MEMBERSHIP:
	case PACKET_DROP_MEMBERSHIP:
	{
		struct packet_mreq_max mreq;
		int len = optlen;
		memset(&mreq, 0, sizeof(mreq));
		if (len < sizeof(struct packet_mreq))
			return -EINVAL;
		if (len > sizeof(mreq))
			len = sizeof(mreq);
		if (copy_from_user(&mreq, optval, len))
			return -EFAULT;
		if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
			return -EINVAL;
		if (optname == PACKET_ADD_MEMBERSHIP)
			ret = packet_mc_add(sk, &mreq);
		else
			ret = packet_mc_drop(sk, &mreq);
		return ret;
	}

	case PACKET_RX_RING:
	case PACKET_TX_RING:
	{
		union tpacket_req_u req_u;
		int len;

		switch (po->tp_version) {
		case TPACKET_V1:
		case TPACKET_V2:
			len = sizeof(req_u.req);
			break;
		case TPACKET_V3:
		default:
			len = sizeof(req_u.req3);
			break;
		}
		if (optlen < len)
			return -EINVAL;
		if (copy_from_user(&req_u.req, optval, len))
			return -EFAULT;
		return packet_set_ring(sk, &req_u, 0,
			optname == PACKET_TX_RING);
	}
	case PACKET_COPY_THRESH:
	{
		int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		pkt_sk(sk)->copy_thresh = val;
		return 0;
	}
	case PACKET_VERSION:
	{
		int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;
		switch (val) {
		case TPACKET_V1:
		case TPACKET_V2:
		case TPACKET_V3:
			break;
		default:
			return -EINVAL;
		}
		lock_sock(sk);
		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
			ret = -EBUSY;
		} else {
			po->tp_version = val;
			ret = 0;
		}
		release_sock(sk);
		return ret;
	}
	case PACKET_RESERVE:
	{
		unsigned int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
			return -EBUSY;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;
		if (val > INT_MAX)
			return -EINVAL;
		po->tp_reserve = val;
		return 0;
	}
	case PACKET_LOSS:
	{
		unsigned int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
			return -EBUSY;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;
		po->tp_loss = !!val;
		return 0;
	}
	case PACKET_AUXDATA:
	{
		int val;

		if (optlen < sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		po->auxdata = !!val;
		return 0;
	}
	case PACKET_ORIGDEV:
	{
		int val;

		if (optlen < sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		po->origdev = !!val;
		return 0;
	}
	case PACKET_VNET_HDR:
	{
		int val;

		if (sock->type != SOCK_RAW)
			return -EINVAL;
		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
			return -EBUSY;
		if (optlen < sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		po->has_vnet_hdr = !!val;
		return 0;
	}
	case PACKET_TIMESTAMP:
	{
		int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		po->tp_tstamp = val;
		return 0;
	}
	case PACKET_FANOUT:
	{
		int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		return fanout_add(sk, val & 0xffff, val >> 16);
	}
	case PACKET_FANOUT_DATA:
	{
		if (!po->fanout)
			return -EINVAL;

		return fanout_set_data(po, optval, optlen);
	}
	case PACKET_TX_HAS_OFF:
	{
		unsigned int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
			return -EBUSY;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;
		po->tp_tx_has_off = !!val;
		return 0;
	}
	case PACKET_QDISC_BYPASS:
	{
		int val;

		if (optlen != sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

		po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
		return 0;
	}
	default:
		return -ENOPROTOOPT;
	}
}

Project: linux
File: af_packet.c

static void packet_flush_mclist(struct sock *sk)
{
	struct packet_sock *po = pkt_sk(sk);
	struct packet_mclist *ml;

	if (!po->mclist)
		return;

	rtnl_lock();
	while ((ml = po->mclist) != NULL) {
		struct net_device *dev;

		po->mclist = ml->next;
		dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
		if (dev != NULL)
			packet_dev_mc(dev, ml, -1);
		kfree(ml);
	}
	rtnl_unlock();
}

Project: linux
File: af_packet.c

static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
{
	unsigned int block_nr = req->tp_block_nr;
	struct pgv *pg_vec;
	int i;

	pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
	if (unlikely(!pg_vec))
		goto out;

	for (i = 0; i < block_nr; i++) {
		pg_vec[i].buffer = alloc_one_pg_vec_page(order);
		if (unlikely(!pg_vec[i].buffer))
			goto out_free_pgvec;
	}

out:
	return pg_vec;

out_free_pgvec:
	free_pg_vec(pg_vec, order, block_nr);
	pg_vec = NULL;
	goto out;
}

Project: linux
File: af_packet.c

static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
			  int *uaddr_len, int peer)
{
	struct net_device *dev;
	struct sock *sk = sock->sk;
	struct packet_sock *po = pkt_sk(sk);
	DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);

	if (peer)
		return -EOPNOTSUPP;

	sll->sll_family = AF_PACKET;
	sll->sll_ifindex = po->ifindex;
	sll->sll_protocol = po->num;
	sll->sll_pkttype = 0;
	rcu_read_lock();
	dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
	if (dev) {
		sll->sll_hatype = dev->type;
		sll->sll_halen = dev->addr_len;
		memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
	} else {
		sll->sll_hatype = 0;	/* Bad: we have no ARPHRD_UNSPEC */
		sll->sll_halen = 0;
	}
	rcu_read_unlock();
	*uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;

	return 0;
}

Project: linux
File: af_packet.c

static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
			unsigned int len)
{
	int i;

	for (i = 0; i < len; i++) {
		if (likely(pg_vec[i].buffer)) {
			if (is_vmalloc_addr(pg_vec[i].buffer))
				vfree(pg_vec[i].buffer);
			else
				free_pages((unsigned long)pg_vec[i].buffer,
					   order);
			pg_vec[i].buffer = NULL;
		}
	}
	kfree(pg_vec);
}

Project: linux
File: af_packet.c

static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
		struct tpacket_block_desc *pbd1, __u32 status)
{
	/* Flush everything minus the block header */

#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
	u8 *start, *end;

	start = (u8 *)pbd1;

	/* Skip the block header(we know header WILL fit in 4K) */
	start += PAGE_SIZE;

	end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
	for (; start < end; start += PAGE_SIZE)
		flush_dcache_page(pgv_to_page(start));

	smp_wmb();
#endif

	/* Now update the block status. */

	BLOCK_STATUS(pbd1) = status;

	/* Flush the block header */

#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
	start = (u8 *)pbd1;
	flush_dcache_page(pgv_to_page(start));

	smp_wmb();
#endif
}

Project: linux
File: af_packet.c

static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
	struct sk_buff *skb;
	struct net_device *dev;
	__be16 proto;
	unsigned char *addr;
	int err, reserve = 0;
	struct sockcm_cookie sockc;
	struct virtio_net_hdr vnet_hdr = { 0 };
	int offset = 0;
	struct packet_sock *po = pkt_sk(sk);
	int hlen, tlen, linear;
	int extra_len = 0;

	/*
	 *	Get and verify the address.
	 */

	if (likely(saddr == NULL)) {
		dev	= packet_cached_dev_get(po);
		proto	= po->num;
		addr	= NULL;
	} else {
		err = -EINVAL;
		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
			goto out;
		if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
			goto out;
		proto	= saddr->sll_protocol;
		addr	= saddr->sll_addr;
		dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
	}

	err = -ENXIO;
	if (unlikely(dev == NULL))
		goto out_unlock;
	err = -ENETDOWN;
	if (unlikely(!(dev->flags & IFF_UP)))
		goto out_unlock;

	sockc.tsflags = sk->sk_tsflags;
	sockc.mark = sk->sk_mark;
	if (msg->msg_controllen) {
		err = sock_cmsg_send(sk, msg, &sockc);
		if (unlikely(err))
			goto out_unlock;
	}

	if (sock->type == SOCK_RAW)
		reserve = dev->hard_header_len;
	if (po->has_vnet_hdr) {
		err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
		if (err)
			goto out_unlock;
	}

	if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
		if (!netif_supports_nofcs(dev)) {
			err = -EPROTONOSUPPORT;
			goto out_unlock;
		}
		extra_len = 4; /* We're doing our own CRC */
	}

	err = -EMSGSIZE;
	if (!vnet_hdr.gso_type &&
	    (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
		goto out_unlock;

	err = -ENOBUFS;
	hlen = LL_RESERVED_SPACE(dev);
	tlen = dev->needed_tailroom;
	linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
	linear = max(linear, min_t(int, len, dev->hard_header_len));
	skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
			       msg->msg_flags & MSG_DONTWAIT, &err);
	if (skb == NULL)
		goto out_unlock;

	skb_set_network_header(skb, reserve);

	err = -EINVAL;
	if (sock->type == SOCK_DGRAM) {
		offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
		if (unlikely(offset < 0))
			goto out_free;
	}

	/* Returns -EFAULT on error */
	err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
	if (err)
		goto out_free;

	if (sock->type == SOCK_RAW &&
	    !dev_validate_header(dev, skb->data, len)) {
		err = -EINVAL;
		goto out_free;
	}

	sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);

	if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
	    !packet_extra_vlan_len_allowed(dev, skb)) {
		err = -EMSGSIZE;
		goto out_free;
	}

	skb->protocol = proto;
	skb->dev = dev;
	skb->priority = sk->sk_priority;
	skb->mark = sockc.mark;

	packet_pick_tx_queue(dev, skb);

	if (po->has_vnet_hdr) {
		err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
		if (err)
			goto out_free;
		len += sizeof(vnet_hdr);
	}

	skb_probe_transport_header(skb, reserve);

	if (unlikely(extra_len == 4))
		skb->no_fcs = 1;

	err = po->xmit(skb);
	if (err > 0 && (err = net_xmit_errno(err)) != 0)
		goto out_unlock;

	dev_put(dev);

	return len;

out_free:
	kfree_skb(skb);
out_unlock:
	if (dev)
		dev_put(dev);
out:
	return err;
}

Project: linux
File: af_packet.c

	__releases(RCU)
{
	rcu_read_unlock();
}

Project: linux
File: af_packet.c

static int packet_seq_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &packet_seq_ops,
			    sizeof(struct seq_net_private));
}