kernel/linux.git/drivers/net/wan/lapbether.c, branch linux-4.4.y

net: lapbether: Prevent racing when checking whether the netif is running

2021-05-22T08:38:24+00:00

[ Upstream commit 5acd0cfbfbb5a688da1bfb1a2152b0c855115a35 ] There are two "netif_running" checks in this driver. One is in "lapbeth_xmit" and the other is in "lapbeth_rcv". They serve to make sure that the LAPB APIs called in these functions are called before "lapb_unregister" is called by the "ndo_stop" function. However, these "netif_running" checks are unreliable, because it's possible that immediately after "netif_running" returns true, "ndo_stop" is called (which causes "lapb_unregister" to be called). This patch adds locking to make sure "lapbeth_xmit" and "lapbeth_rcv" can reliably check and ensure the netif is running while doing their work. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xie He Acked-by: Martin Schiller Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: lapbether: Remove netif_start_queue / netif_stop_queue

2021-03-17T15:07:19+00:00

commit f7d9d4854519fdf4d45c70a4d953438cd88e7e58 upstream. For the devices in this driver, the default qdisc is "noqueue", because their "tx_queue_len" is 0. In function "__dev_queue_xmit" in "net/core/dev.c", devices with the "noqueue" qdisc are specially handled. Packets are transmitted without being queued after a "dev->flags & IFF_UP" check. However, it's possible that even if this check succeeds, "ops->ndo_stop" may still have already been called. This is because in "__dev_close_many", "ops->ndo_stop" is called before clearing the "IFF_UP" flag. If we call "netif_stop_queue" in "ops->ndo_stop", then it's possible in "__dev_queue_xmit", it sees the "IFF_UP" flag is present, and then it checks "netif_xmit_stopped" and finds that the queue is already stopped. In this case, it will complain that: "Virtual device ... asks to queue packet!" To prevent "__dev_queue_xmit" from generating this complaint, we should not call "netif_stop_queue" in "ops->ndo_stop". We also don't need to call "netif_start_queue" in "ops->ndo_open", because after a netdev is allocated and registered, the "__QUEUE_STATE_DRV_XOFF" flag is initially not set, so there is no need to call "netif_start_queue" to clear it. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xie He Acked-by: Martin Schiller Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

drivers/net/wan/lapbether: Make skb->protocol consistent with the header

2020-10-14T07:46:20+00:00

[ Upstream commit 83f9a9c8c1edc222846dc1bde6e3479703e8e5a3 ] This driver is a virtual driver stacked on top of Ethernet interfaces. When this driver transmits data on the Ethernet device, the skb->protocol setting is inconsistent with the Ethernet header prepended to the skb. This causes a user listening on the Ethernet interface with an AF_PACKET socket, to see different sll_protocol values for incoming and outgoing frames, because incoming frames would have this value set by parsing the Ethernet header. This patch changes the skb->protocol value for outgoing Ethernet frames, making it consistent with the Ethernet header prepended. This makes a user listening on the Ethernet device with an AF_PACKET socket, to see the same sll_protocol value for incoming and outgoing frames. Cc: Martin Schiller Signed-off-by: Xie He Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

drivers/net/wan/lapbether: Set network_header before transmitting

2020-09-23T06:44:23+00:00

[ Upstream commit 91244d108441013b7367b3b4dcc6869998676473 ] Set the skb's network_header before it is passed to the underlying Ethernet device for transmission. This patch fixes the following issue: When we use this driver with AF_PACKET sockets, there would be error messages of: protocol 0805 is buggy, dev (Ethernet interface name) printed in the system "dmesg" log. This is because skbs passed down to the Ethernet device for transmission don't have their network_header properly set, and the dev_queue_xmit_nit function in net/core/dev.c complains about this. Reason of setting the network_header to this place (at the end of the Ethernet header, and at the beginning of the Ethernet payload): Because when this driver receives an skb from the Ethernet device, the network_header is also set at this place. Cc: Martin Schiller Signed-off-by: Xie He Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

drivers/net/wan/lapbether: Added needed_tailroom

2020-09-23T06:44:23+00:00

[ Upstream commit 1ee39c1448c4e0d480c5b390e2db1987561fb5c2 ] The underlying Ethernet device may request necessary tailroom to be allocated by setting needed_tailroom. This driver should also set needed_tailroom to request the tailroom needed by the underlying Ethernet device to be allocated. Cc: Willem de Bruijn Cc: Martin Schiller Signed-off-by: Xie He Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

drivers/net/wan/lapbether: Added needed_headroom and a skb->len check

2020-08-21T08:53:03+00:00

[ Upstream commit c7ca03c216acb14466a713fedf1b9f2c24994ef2 ] 1. Added a skb->len check This driver expects upper layers to include a pseudo header of 1 byte when passing down a skb for transmission. This driver will read this 1-byte header. This patch added a skb->len check before reading the header to make sure the header exists. 2. Changed to use needed_headroom instead of hard_header_len to request necessary headroom to be allocated In net/packet/af_packet.c, the function packet_snd first reserves a headroom of length (dev->hard_header_len + dev->needed_headroom). Then if the socket is a SOCK_DGRAM socket, it calls dev_hard_header, which calls dev->header_ops->create, to create the link layer header. If the socket is a SOCK_RAW socket, it "un-reserves" a headroom of length (dev->hard_header_len), and assumes the user to provide the appropriate link layer header. So according to the logic of af_packet.c, dev->hard_header_len should be the length of the header that would be created by dev->header_ops->create. However, this driver doesn't provide dev->header_ops, so logically dev->hard_header_len should be 0. So we should use dev->needed_headroom instead of dev->hard_header_len to request necessary headroom to be allocated. This change fixes kernel panic when this driver is used with AF_PACKET SOCK_RAW sockets. Call stack when panic: [ 168.399197] skbuff: skb_under_panic: text:ffffffff819d95fb len:20 put:14 head:ffff8882704c0a00 data:ffff8882704c09fd tail:0x11 end:0xc0 dev:veth0 ... [ 168.399255] Call Trace: [ 168.399259] skb_push.cold+0x14/0x24 [ 168.399262] eth_header+0x2b/0xc0 [ 168.399267] lapbeth_data_transmit+0x9a/0xb0 [lapbether] [ 168.399275] lapb_data_transmit+0x22/0x2c [lapb] [ 168.399277] lapb_transmit_buffer+0x71/0xb0 [lapb] [ 168.399279] lapb_kick+0xe3/0x1c0 [lapb] [ 168.399281] lapb_data_request+0x76/0xc0 [lapb] [ 168.399283] lapbeth_xmit+0x56/0x90 [lapbether] [ 168.399286] dev_hard_start_xmit+0x91/0x1f0 [ 168.399289] ? irq_init_percpu_irqstack+0xc0/0x100 [ 168.399291] __dev_queue_xmit+0x721/0x8e0 [ 168.399295] ? packet_parse_headers.isra.0+0xd2/0x110 [ 168.399297] dev_queue_xmit+0x10/0x20 [ 168.399298] packet_sendmsg+0xbf0/0x19b0 ...... Cc: Willem de Bruijn Cc: Martin Schiller Cc: Brian Norris Signed-off-by: Xie He Acked-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

drivers/net/wan/lapbether: Fixed the value of hard_header_len

2020-07-31T14:43:12+00:00

[ Upstream commit 9dc829a135fb5927f1519de11286e2bbb79f5b66 ] When this driver transmits data, first this driver will remove a pseudo header of 1 byte, then the lapb module will prepend the LAPB header of 2 or 3 bytes, then this driver will prepend a length field of 2 bytes, then the underlying Ethernet device will prepend its own header. So, the header length required should be: -1 + 3 + 2 + "the header length needed by the underlying device". This patch fixes kernel panic when this driver is used with AF_PACKET SOCK_DGRAM sockets. Signed-off-by: Xie He Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

netfilter: Remove spurios included of netfilter.h

2015-06-18T19:14:32+00:00

While testing my netfilter changes I noticed several files where recompiling unncessarily because they unncessarily included netfilter.h. Signed-off-by: "Eric W. Biederman" Signed-off-by: Pablo Neira Ayuso

net: set name_assign_type in alloc_netdev()

2014-07-15T23:12:48+00:00

Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert all users to pass NET_NAME_UNKNOWN. Coccinelle patch: @@ expression sizeof_priv, name, setup, txqs, rxqs, count; @@ ( -alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs) +alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs) | -alloc_netdev_mq(sizeof_priv, name, setup, count) +alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count) | -alloc_netdev(sizeof_priv, name, setup) +alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup) ) v9: move comments here from the wrong commit Signed-off-by: Tom Gundersen Reviewed-by: David Herrmann Signed-off-by: David S. Miller

net: pass info struct via netdevice notifier

2013-05-28T20:11:01+00:00

So far, only net_device * could be passed along with netdevice notifier event. This patch provides a possibility to pass custom structure able to provide info that event listener needs to know. Signed-off-by: Jiri Pirko v2->v3: fix typo on simeth shortened dev_getter shortened notifier_info struct name v1->v2: fix notifier_call parameter in call_netdevice_notifier() Signed-off-by: David S. Miller