| Age | Commit message (Collapse) | Author | |
|---|---|---|---|
| 2014-07-14 | net: pppoe: use correct channel MTU when using Multilink PPP | Christoph Schulz | |
| The PPP channel MTU is used with Multilink PPP when ppp_mp_explode() (see ppp_generic module) tries to determine how big a fragment might be. According to RFC 1661, the MTU excludes the 2-byte PPP protocol field, see the corresponding comment and code in ppp_mp_explode(): /* * hdrlen includes the 2-byte PPP protocol field, but the * MTU counts only the payload excluding the protocol field. * (RFC1661 Section 2) */ mtu = pch->chan->mtu - (hdrlen - 2); However, the pppoe module *does* include the PPP protocol field in the channel MTU, which is wrong as it causes the PPP payload to be 1-2 bytes too big under certain circumstances (one byte if PPP protocol compression is used, two otherwise), causing the generated Ethernet packets to be dropped. So the pppoe module has to subtract two bytes from the channel MTU. This error only manifests itself when using Multilink PPP, as otherwise the channel MTU is not used anywhere. In the following, I will describe how to reproduce this bug. We configure two pppd instances for multilink PPP over two PPPoE links, say eth2 and eth3, with a MTU of 1492 bytes for each link and a MRRU of 2976 bytes. (This MRRU is computed by adding the two link MTUs and subtracting the MP header twice, which is 4 bytes long.) The necessary pppd statements on both sides are "multilink mtu 1492 mru 1492 mrru 2976". On the client side, we additionally need "plugin rp-pppoe.so eth2" and "plugin rp-pppoe.so eth3", respectively; on the server side, we additionally need to start two pppoe-server instances to be able to establish two PPPoE sessions, one over eth2 and one over eth3. We set the MTU of the PPP network interface to the MRRU (2976) on both sides of the connection in order to make use of the higher bandwidth. (If we didn't do that, IP fragmentation would kick in, which we want to avoid.) Now we send a ICMPv4 echo request with a payload of 2948 bytes from client to server over the PPP link. This results in the following network packet: 2948 (echo payload) + 8 (ICMPv4 header) + 20 (IPv4 header) --------------------- 2976 (PPP payload) These 2976 bytes do not exceed the MTU of the PPP network interface, so the IP packet is not fragmented. Now the multilink PPP code in ppp_mp_explode() prepends one protocol byte (0x21 for IPv4), making the packet one byte bigger than the negotiated MRRU. So this packet would have to be divided in three fragments. But this does not happen as each link MTU is assumed to be two bytes larger. So this packet is diveded into two fragments only, one of size 1489 and one of size 1488. Now we have for that bigger fragment: 1489 (PPP payload) + 4 (MP header) + 2 (PPP protocol field for the MP payload (0x3d)) + 6 (PPPoE header) -------------------------- 1501 (Ethernet payload) This packet exceeds the link MTU and is discarded. If one configures the link MTU on the client side to 1501, one can see the discarded Ethernet frames with tcpdump running on the client. A ping -s 2948 -c 1 192.168.15.254 leads to the smaller fragment that is correctly received on the server side: (tcpdump -vvvne -i eth3 pppoes and ppp proto 0x3d) 52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864), length 1514: PPPoE [ses 0x3] MLPPP (0x003d), length 1494: seq 0x000, Flags [end], length 1492 and to the bigger fragment that is not received on the server side: (tcpdump -vvvne -i eth2 pppoes and ppp proto 0x3d) 52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864), length 1515: PPPoE [ses 0x5] MLPPP (0x003d), length 1495: seq 0x000, Flags [begin], length 1493 With the patch below, we correctly obtain three fragments: 52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864), length 1514: PPPoE [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000, Flags [begin], length 1492 52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864), length 1514: PPPoE [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000, Flags [none], length 1492 52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864), length 27: PPPoE [ses 0x1] MLPPP (0x003d), length 7: seq 0x000, Flags [end], length 5 And the ICMPv4 echo request is successfully received at the server side: IP (tos 0x0, ttl 64, id 21925, offset 0, flags [DF], proto ICMP (1), length 2976) 192.168.222.2 > 192.168.15.254: ICMP echo request, id 30530, seq 0, length 2956 The bug was introduced in commit c9aa6895371b2a257401f59d3393c9f7ac5a8698 ("[PPPOE]: Advertise PPPoE MTU") from the very beginning. This patch applies to 3.10 upwards but the fix can be applied (with minor modifications) to kernels as old as 2.6.32. Signed-off-by: Christoph Schulz <develop@kristov.de> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2013-12-26 | ppp: slight optimization of addr compare | dingtianhong | |
| Use possibly more efficient ether_addr_equal to instead of memcmp. Cc: Michal Ostrowski <mostrows@earthlink.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2013-11-20 | net: rework recvmsg handler msg_name and msg_namelen logic | Hannes Frederic Sowa | |
| This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller <davem@davemloft.net> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2013-05-28 | net: pass info struct via netdevice notifier | Jiri Pirko | |
| 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 <jiri@resnulli.us> 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 <davem@davemloft.net> | |||
| 2013-02-18 | net: proc: change proc_net_remove to remove_proc_entry | Gao feng | |
| proc_net_remove is only used to remove proc entries that under /proc/net,it's not a general function for removing proc entries of netns. if we want to remove some proc entries which under /proc/net/stat/, we still need to call remove_proc_entry. this patch use remove_proc_entry to replace proc_net_remove. we can remove proc_net_remove after this patch. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2013-02-18 | net: proc: change proc_net_fops_create to proc_create | Gao feng | |
| Right now, some modules such as bonding use proc_create to create proc entries under /proc/net/, and other modules such as ipv4 use proc_net_fops_create. It looks a little chaos.this patch changes all of proc_net_fops_create to proc_create. we can remove proc_net_fops_create after this patch. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2012-09-22 | pppoe: drop PPPOX_ZOMBIEs in pppoe_release | Xiaodong Xu | |
| When PPPOE is running over a virtual ethernet interface (e.g., a bonding interface) and the user tries to delete the interface in case the PPPOE state is ZOMBIE, the kernel will loop forever while unregistering net_device for the reference count is not decreased to zero which should have been done with dev_put(). Signed-off-by: Xiaodong Xu <stid.smth@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2012-05-19 | ppp: avoid false drop_monitor false positives | Eric Dumazet | |
| Call consume_skb() in place of kfree_skb() were appropriate. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2012-05-17 | pppoe: remove unused return value from two methods. | Rami Rosen | |
| The patch removes unused return value from __delete_item() and delete_item() methods in drivers/net/ppp/pppoe.c. Signed-off-by: Rami Rosen <ramirose@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2012-03-04 | ppp: Replace uses of <linux/if_ppp.h> with <linux/ppp-ioctl.h> | Paul Mackerras | |
| Since all that include/linux/if_ppp.h does is #include <linux/ppp-ioctl.h>, this replaces the occurrences of #include <linux/if_ppp.h> with #include <linux/ppp-ioctl.h>. It also corrects an error in Documentation/networking/l2tp.txt, where it referenced include/linux/if_ppp.h as the source of some definitions that are actually now defined in include/linux/if_pppol2tp.h. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net> | |||
| 2011-08-27 | ppp: Move the PPP drivers | Jeff Kirsher | |
| Move the PPP drivers into drivers/net/ppp/ and make the necessary Kconfig and Makefile changes. CC: Paul Mackerras <paulus@samba.org> CC: Frank Cusack <fcusack@fcusack.com> CC: Michal Ostrowski <mostrows@speakeasy.net> CC: Michal Ostrowski <mostrows@earthlink.net> CC: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> | |||
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index : linux-toradex.git | |
| Linux kernel for Apalis, Colibri and Verdin modules | Marcel Ziswiler |
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