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2021-03-03net: l2tp: reduce log level of messages in receive path, add counter insteadMatthias Schiffer1-0/+6
Commit 5ee759cda51b ("l2tp: use standard API for warning log messages") changed a number of warnings about invalid packets in the receive path so that they are always shown, instead of only when a special L2TP debug flag is set. Even with rate limiting these warnings can easily cause significant log spam - potentially triggered by a malicious party sending invalid packets on purpose. In addition these warnings were noticed by projects like Tunneldigger [1], which uses L2TP for its data path, but implements its own control protocol (which is sufficiently different from L2TP data packets that it would always be passed up to userspace even with future extensions of L2TP). Some of the warnings were already redundant, as l2tp_stats has a counter for these packets. This commit adds one additional counter for invalid packets that are passed up to userspace. Packets with unknown session are not counted as invalid, as there is nothing wrong with the format of these packets. With the additional counter, all of these messages are either redundant or benign, so we reduce them to pr_debug_ratelimited(). [1] https://github.com/wlanslovenija/tunneldigger/issues/160 Fixes: 5ee759cda51b ("l2tp: use standard API for warning log messages") Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: move to smaller ops wherever possibleJakub Kicinski1-3/+3
Bulk of the genetlink users can use smaller ops, move them. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-29l2tp: report rx cookie discards in netlink getTom Parkin1-0/+6
When an L2TPv3 session receives a data frame with an incorrect cookie l2tp_core logs a warning message and bumps a stats counter to reflect the fact that the packet has been dropped. However, the stats counter in question is missing from the l2tp_netlink get message for tunnel and session instances. Include the statistic in the netlink get response. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-03l2tp: drop net argument from l2tp_tunnel_createTom Parkin1-1/+1
The argument is unused, so remove it. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-22l2tp: remove tunnel and session debug flags fieldTom Parkin1-14/+2
The l2tp subsystem now uses standard kernel logging APIs for informational and warning messages, and tracepoints for debug information. Now that the tunnel and session debug flags are unused, remove the field from the core structures. Various system calls (in the case of l2tp_ppp) and netlink messages handle the getting and setting of debug flags. To avoid userspace breakage don't modify the API of these calls; simply ignore set requests, and send dummy data for get requests. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30l2tp: return void from l2tp_session_deleteTom Parkin1-1/+1
l2tp_session_delete is used to schedule a session instance for deletion. The function itself always returns zero, and none of its direct callers check its return value, so have the function return void. This change de-facto changes the l2tp netlink session_delete callback prototype since all pseudowires currently use l2tp_session_delete for their implementation of that operation. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23l2tp: cleanup netlink tunnel create address handlingTom Parkin1-24/+33
When creating an L2TP tunnel using the netlink API, userspace must either pass a socket FD for the tunnel to use (for managed tunnels), or specify the tunnel source/destination address (for unmanaged tunnels). Since source/destination addresses may be AF_INET or AF_INET6, the l2tp netlink code has conditionally compiled blocks to support IPv6. Rather than embedding these directly into l2tp_nl_cmd_tunnel_create (where it makes the code difficult to read and confuses checkpatch to boot) split the handling of address-related attributes into a separate function. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23l2tp: cleanup netlink send of tunnel address informationTom Parkin1-56/+70
l2tp_nl_tunnel_send has conditionally compiled code to support AF_INET6, which makes the code difficult to follow and triggers checkpatch warnings. Split the code out into functions to handle the AF_INET v.s. AF_INET6 cases, which both improves readability and resolves the checkpatch warnings. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23l2tp: cleanup comparisons to NULLTom Parkin1-12/+11
checkpatch warns about comparisons to NULL, e.g. CHECK: Comparison to NULL could be written "!rt" #474: FILE: net/l2tp/l2tp_ip.c:474: + if (rt == NULL) { These sort of comparisons are generally clearer and more readable the way checkpatch suggests, so update l2tp accordingly. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22l2tp: cleanup difficult-to-read line breaksTom Parkin1-40/+29
Some l2tp code had line breaks which made the code more difficult to read. These were originally motivated by the 80-character line width coding guidelines, but were actually a negative from the perspective of trying to follow the code. Remove these linebreaks for clearer code, even if we do exceed 80 characters in width in some places. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22l2tp: cleanup commentsTom Parkin1-2/+1
Modify some l2tp comments to better adhere to kernel coding style, as reported by checkpatch.pl. Add descriptive comments for the l2tp per-net spinlocks to document their use. Fix an incorrect comment in l2tp_recv_common: RFC2661 section 5.4 states that: "The LNS controls enabling and disabling of sequence numbers by sending a data message with or without sequence numbers present at any time during the life of a session." l2tp handles this correctly in l2tp_recv_common, but the comment around the code was incorrect and confusing. Fix up the comment accordingly. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22l2tp: cleanup whitespace useTom Parkin1-1/+2
Fix up various whitespace issues as reported by checkpatch.pl: * remove spaces around operators where appropriate, * add missing blank lines following declarations, * remove multiple blank lines, or trailing blank lines at the end of functions. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-08l2tp: Allow management of tunnels and session in user namespaceMichael Weiß1-8/+8
Creation and management of L2TPv3 tunnels and session through netlink requires CAP_NET_ADMIN. However, a process with CAP_NET_ADMIN in a non-initial user namespace gets an EPERM due to the use of the genetlink GENL_ADMIN_PERM flag. Thus, management of L2TP VPNs inside an unprivileged container won't work. We replaced the GENL_ADMIN_PERM by the GENL_UNS_ADMIN_PERM flag similar to other network modules which also had this problem, e.g., openvswitch (commit 4a92602aa1cd "openvswitch: allow management from inside user namespaces") and nl80211 (commit 5617c6cd6f844 "nl80211: Allow privileged operations from user namespaces"). I tested this in the container runtime trustm3 (trustm3.github.io) and was able to create l2tp tunnels and sessions in unpriviliged (user namespaced) containers using a private network namespace. For other runtimes such as docker or lxc this should work, too. Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27genetlink: optionally validate strictly/dumpsJohannes Berg1-0/+9
Add options to strictly validate messages and dump messages, sometimes perhaps validating dump messages non-strictly may be required, so add an option for that as well. Since none of this can really be applied to existing commands, set the options everwhere using the following spatch: @@ identifier ops; expression X; @@ struct genl_ops ops[] = { ..., { .cmd = X, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, ... }, ... }; For new commands one should just not copy the .validate 'opt-out' flags and thus get strict validation. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27netlink: make nla_nest_start() add NLA_F_NESTED flagMichal Kubecek1-2/+2
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-22genetlink: make policy common to familyJohannes Berg1-9/+1
Since maxattr is common, the policy can't really differ sanely, so make it common as well. The only user that did in fact manage to make a non-common policy is taskstats, which has to be really careful about it (since it's still using a common maxattr!). This is no longer supported, but we can fake it using pre_doit. This reduces the size of e.g. nl80211.o (which has lots of commands): text data bss dec hex filename 398745 14323 2240 415308 6564c net/wireless/nl80211.o (before) 397913 14331 2240 414484 65314 net/wireless/nl80211.o (after) -------------------------------- -832 +8 0 -824 Which is obviously just 8 bytes for each command, and an added 8 bytes for the new policy pointer. I'm not sure why the ops list is counted as .text though. Most of the code transformations were done using the following spatch: @ops@ identifier OPS; expression POLICY; @@ struct genl_ops OPS[] = { ..., { - .policy = POLICY, }, ... }; @@ identifier ops.OPS; expression ops.POLICY; identifier fam; expression M; @@ struct genl_family fam = { .ops = OPS, .maxattr = M, + .policy = POLICY, ... }; This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing the cb->data as ops, which we want to change in a later genl patch. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: split l2tp_session_get()Guillaume Nault1-2/+2
l2tp_session_get() is used for two different purposes. If 'tunnel' is NULL, the session is searched globally in the supplied network namespace. Otherwise it is searched exclusively in the tunnel context. Callers always know the context in which they need to search the session. But some of them do provide both a namespace and a tunnel, making the semantic of the call unclear. This patch defines l2tp_tunnel_get_session() for lookups done in a tunnel and restricts l2tp_session_get() to namespace searches. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11l2tp: define l2tp_tunnel_uses_xfrm()Guillaume Nault1-6/+1
Use helper function to figure out if a tunnel is using ipsec. Also, avoid accessing ->sk_policy directly since it's RCU protected. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03l2tp: ignore L2TP_ATTR_MTUGuillaume Nault1-8/+1
This attribute's handling is broken. It can only be used when creating Ethernet pseudo-wires, in which case its value can be used as the initial MTU for the l2tpeth device. However, when handling update requests, L2TP_ATTR_MTU only modifies session->mtu. This value is never propagated to the l2tpeth device. Dump requests also return the value of session->mtu, which is not synchronised anymore with the device MTU. The same problem occurs if the device MTU is properly updated using the generic IFLA_MTU attribute. In this case, session->mtu is not updated, and L2TP_ATTR_MTU will report an invalid value again when dumping the session. It does not seem worthwhile to complexify l2tp_eth.c to synchronise session->mtu with the device MTU. Even the ip-l2tp manpage advises to use 'ip link' to initialise the MTU of l2tpeth devices (iproute2 does not handle L2TP_ATTR_MTU at all anyway). So let's just ignore it entirely. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: drop ->mru from struct l2tp_sessionGuillaume Nault1-9/+1
This field is not used. Treat PPPIOC*MRU the same way as PPPIOC*FLAGS: "get" requests return 0, while "set" requests vadidate the user supplied pointer but discard its value. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: ignore L2TP_ATTR_VLAN_ID netlink attributeGuillaume Nault1-3/+0
The value of this attribute is never used. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27l2tp: ignore L2TP_ATTR_DATA_SEQ netlink attributeGuillaume Nault1-6/+0
The value of this attribute is never used. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-15l2tp: reject creation of non-PPP sessions on L2TPv2 tunnelsGuillaume Nault1-0/+6
The /proc/net/pppol2tp handlers (pppol2tp_seq_*()) iterate over all L2TPv2 tunnels, and rightfully expect that only PPP sessions can be found there. However, l2tp_netlink accepts creating Ethernet sessions regardless of the underlying tunnel version. This confuses pppol2tp_seq_session_show(), which expects that l2tp_session_priv() returns a pppol2tp_session structure. When the session is an Ethernet pseudo-wire, a struct l2tp_eth_sess is returned instead. This leads to invalid memory access when pppol2tp_session_get_sock() later tries to dereference ps->sk. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13l2tp: hold reference on tunnels in netlink dumpsGuillaume Nault1-3/+8
l2tp_tunnel_find_nth() is unsafe: no reference is held on the returned tunnel, therefore it can be freed whenever the caller uses it. This patch defines l2tp_tunnel_get_nth() which works similarly, but also takes a reference on the returned tunnel. The caller then has to drop it after it stops using the tunnel. Convert netlink dumps to make them safe against concurrent tunnel deletion. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11l2tp: fix race in duplicate tunnel detectionGuillaume Nault1-6/+0
We can't use l2tp_tunnel_find() to prevent l2tp_nl_cmd_tunnel_create() from creating a duplicate tunnel. A tunnel can be concurrently registered after l2tp_tunnel_find() returns. Therefore, searching for duplicates must be done at registration time. Finally, remove l2tp_tunnel_find() entirely as it isn't use anywhere anymore. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11l2tp: fix races in tunnel creationGuillaume Nault1-3/+13
l2tp_tunnel_create() inserts the new tunnel into the namespace's tunnel list and sets the socket's ->sk_user_data field, before returning it to the caller. Therefore, there are two ways the tunnel can be accessed and freed, before the caller even had the opportunity to take a reference. In practice, syzbot could crash the module by closing the socket right after a new tunnel was returned to pppol2tp_create(). This patch moves tunnel registration out of l2tp_tunnel_create(), so that the caller can safely hold a reference before publishing the tunnel. This second step is done with the new l2tp_tunnel_register() function, which is now responsible for associating the tunnel to its socket and for inserting it into the namespace's list. While moving the code to l2tp_tunnel_register(), a few modifications have been done. First, the socket validation tests are done in a helper function, for clarity. Also, modifying the socket is now done after having inserted the tunnel to the namespace's tunnels list. This will allow insertion to fail, without having to revert theses modifications in the error path (a followup patch will check for duplicate tunnels before insertion). Either the socket is a kernel socket which we control, or it is a user-space socket for which we have a reference on the file descriptor. In any case, the socket isn't going to be closed from under us. Reported-by: syzbot+fbeeb5c3b538e8545644@syzkaller.appspotmail.com Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19l2tp: remove switch block in l2tp_nl_cmd_session_create()Lorenzo Bianconi1-21/+0
Remove the switch block in l2tp_nl_cmd_session_create() that checks pseudowire-specific parameters since just L2TP_PWTYPE_ETH and L2TP_PWTYPE_PPP are currently supported and no actual checks are performed. Moreover the L2TP_PWTYPE_IP/default case presents a harmless issue in error handling (break instead of goto out_tunnel) Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Acked-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19l2tp: remove l2specific_len configurable parameterLorenzo Bianconi1-4/+0
Remove l2specific_len configuration parameter since now L2-Specific Sublayer length is computed according to l2specific_type provided by userspace. Reviewed-by: Guillaume Nault <g.nault@alphalink.fr> Tested-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19l2tp: double-check l2specific_type provided by userspaceLorenzo Bianconi1-2/+9
Add sanity check on l2specific_type provided by userspace in l2tp_nl_cmd_session_create() since just L2TP_L2SPECTYPE_DEFAULT and L2TP_L2SPECTYPE_NONE are currently supported. Moreover explicitly set l2specific_type to L2TP_L2SPECTYPE_DEFAULT only if the userspace does not provide a value for it Reviewed-by: Guillaume Nault <g.nault@alphalink.fr> Tested-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05l2tp: remove configurable payload offsetJames Chapman1-3/+0
If L2TP_ATTR_OFFSET is set to a non-zero value in L2TPv3 tunnels, it results in L2TPv3 packets being transmitted which might not be compliant with the L2TPv3 RFC. This patch has l2tp ignore the offset setting and send all packets with no offset. In more detail: L2TPv2 supports a variable offset from the L2TPv2 header to the payload. The offset value is indicated by an optional field in the L2TP header. Our L2TP implementation already detects the presence of the optional offset and skips that many bytes when handling data received packets. All transmitted packets are always transmitted with no offset. L2TPv3 has no optional offset field in the L2TPv3 packet header. Instead, L2TPv3 defines optional fields in a "Layer-2 Specific Sublayer". At the time when the original L2TP code was written, there was talk at IETF of offset being implemented in a new Layer-2 Specific Sublayer. A L2TP_ATTR_OFFSET netlink attribute was added so that this offset could be configured and the intention was to allow it to be also used to set the tx offset for L2TPv2. However, no L2TPv3 offset was ever specified and the L2TP_ATTR_OFFSET parameter was forgotten about. Setting L2TP_ATTR_OFFSET results in L2TPv3 packets being transmitted with the specified number of bytes padding between L2TPv3 header and payload. This is not compliant with L2TPv3 RFC3931. This change removes the configurable offset altogether while retaining L2TP_ATTR_OFFSET for backwards compatibility. Any L2TP_ATTR_OFFSET value is ignored. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05l2tp: revert "l2tp: fix missing print session offset info"James Chapman1-2/+0
Revert commit 820da5357572 ("l2tp: fix missing print session offset info"). The peer_offset parameter is removed. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05l2tp: revert "l2tp: add peer_offset parameter"James Chapman1-20/+1
Revert commit f15bc54eeecd ("l2tp: add peer_offset parameter"). This is removed because it is adding another configurable offset and configurable offsets are being removed. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-27l2tp: add peer_offset parameterLorenzo Bianconi1-1/+20
Introduce peer_offset parameter in order to add the capability to specify two different values for payload offset on tx/rx side. If just offset is provided by userspace use it for rx side as well in order to maintain compatibility with older l2tp versions Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-27l2tp: fix missing print session offset infoHangbin Liu1-0/+2
Report offset parameter in L2TP_CMD_SESSION_GET command if it has been configured by userspace Fixes: 309795f4bec ("l2tp: Add netlink control API for L2TP") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01l2tp: remove ->ref() and ->deref()Guillaume Nault1-12/+8
The ->ref() and ->deref() callbacks are unused since PPP stopped using them in ee40fb2e1eb5 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU"). We can thus remove them from struct l2tp_session and drop the do_ref parameter of l2tp_session_get*(). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27l2tp: cleanup l2tp_tunnel_delete callsJiri Slaby1-1/+1
l2tp_tunnel_delete does not return anything since commit 62b982eeb458 ("l2tp: fix race condition in l2tp_tunnel_delete"). But call sites of l2tp_tunnel_delete still do casts to void to avoid unused return value warnings. Kill these now useless casts. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Guillaume Nault <g.nault@alphalink.fr> Cc: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Acked-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-19net: l2tp: mark expected switch fall-throughGustavo A. R. Silva1-1/+1
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Notice that in this particular case I replaced the "NOBREAK" comment with a "fall through" comment, which is what GCC is expecting to find. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Acked-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03l2tp: pass tunnel pointer to ->session_create()Guillaume Nault1-4/+4
Using l2tp_tunnel_find() in pppol2tp_session_create() and l2tp_eth_create() is racy, because no reference is held on the returned session. These functions are only used to implement the ->session_create callback which is run by l2tp_nl_cmd_session_create(). Therefore searching for the parent tunnel isn't necessary because l2tp_nl_cmd_session_create() already has a pointer to it and holds a reference. This patch modifies ->session_create()'s prototype to directly pass the the parent tunnel as parameter, thus avoiding searching for it in pppol2tp_session_create() and l2tp_eth_create(). Since we have to touch the ->session_create() call in l2tp_nl_cmd_session_create(), let's also remove the useless conditional: we know that ->session_create isn't NULL at this point because it's already been checked earlier in this same function. Finally, one might be tempted to think that the removed l2tp_tunnel_find() calls were harmless because they would return the same tunnel as the one held by l2tp_nl_cmd_session_create() anyway. But that tunnel might be removed and a new one created with same tunnel Id before the l2tp_tunnel_find() call. In this case l2tp_tunnel_find() would return the new tunnel which wouldn't be protected by the reference held by l2tp_nl_cmd_session_create(). Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28l2tp: hold tunnel used while creating sessions with netlinkGuillaume Nault1-9/+12
Use l2tp_tunnel_get() to retrieve tunnel, so that it can't go away on us. Otherwise l2tp_tunnel_destruct() might release the last reference count concurrently, thus freeing the tunnel while we're using it. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28l2tp: hold tunnel while handling genl TUNNEL_GET commandsGuillaume Nault1-12/+15
Use l2tp_tunnel_get() instead of l2tp_tunnel_find() so that we get a reference on the tunnel, preventing l2tp_tunnel_destruct() from freeing it from under us. Also move l2tp_tunnel_get() below nlmsg_new() so that we only take the reference when needed. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28l2tp: hold tunnel while handling genl tunnel updatesGuillaume Nault1-2/+4
We need to make sure the tunnel is not going to be destroyed by l2tp_tunnel_destruct() concurrently. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28l2tp: hold tunnel while processing genl delete commandGuillaume Nault1-2/+4
l2tp_nl_cmd_tunnel_delete() needs to take a reference on the tunnel, to prevent it from being concurrently freed by l2tp_tunnel_destruct(). Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28l2tp: hold tunnel while looking up sessions in l2tp_netlinkGuillaume Nault1-2/+4
l2tp_tunnel_find() doesn't take a reference on the returned tunnel. Therefore, it's unsafe to use it because the returned tunnel can go away on us anytime. Fix this by defining l2tp_tunnel_get(), which works like l2tp_tunnel_find(), but takes a reference on the returned tunnel. Caller then has to drop this reference using l2tp_tunnel_dec_refcount(). As l2tp_tunnel_dec_refcount() needs to be moved to l2tp_core.h, let's simplify the patch and not move the L2TP_REFCNT_DEBUG part. This code has been broken (not even compiling) in May 2012 by commit a4ca44fa578c ("net: l2tp: Standardize logging styles") and fixed more than two years later by commit 29abe2fda54f ("l2tp: fix missing line continuation"). So it doesn't appear to be used by anyone. Same thing for l2tp_tunnel_free(); instead of moving it to l2tp_core.h, let's just simplify things and call kfree_rcu() directly in l2tp_tunnel_dec_refcount(). Extra assertions and debugging code provided by l2tp_tunnel_free() didn't help catching any of the reference counting and socket handling issues found while working on this series. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-11l2tp: remove useless duplicate session detection in l2tp_netlinkGuillaume Nault1-5/+0
There's no point in checking for duplicate sessions at the beginning of l2tp_nl_cmd_session_create(); the ->session_create() callbacks already return -EEXIST when the session already exists. Furthermore, even if l2tp_session_find() returns NULL, a new session might be created right after the test. So relying on ->session_create() to avoid duplicate session is the only sane behaviour. Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-04l2tp: take reference on sessions being dumpedGuillaume Nault1-2/+5
Take a reference on the sessions returned by l2tp_session_find_nth() (and rename it l2tp_session_get_nth() to reflect this change), so that caller is assured that the session isn't going to disappear while processing it. For procfs and debugfs handlers, the session is held in the .start() callback and dropped in .show(). Given that pppol2tp_seq_session_show() dereferences the associated PPPoL2TP socket and that l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to call the session's .ref() callback to prevent the socket from going away from under us. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01l2tp: take a reference on sessions used in genetlink handlersGuillaume Nault1-13/+26
Callers of l2tp_nl_session_find() need to hold a reference on the returned session since there's no guarantee that it isn't going to disappear from under them. Relying on the fact that no l2tp netlink message may be processed concurrently isn't enough: sessions can be deleted by other means (e.g. by closing the PPPOL2TP socket of a ppp pseudowire). l2tp_nl_cmd_session_delete() is a bit special: it runs a callback function that may require a previous call to session->ref(). In particular, for ppp pseudowires, the callback is l2tp_session_delete(), which then calls pppol2tp_session_close() and dereferences the PPPOL2TP socket. The socket might already be gone at the moment l2tp_session_delete() calls session->ref(), so we need to take a reference during the session lookup. So we need to pass the do_ref variable down to l2tp_session_get() and l2tp_session_get_by_ifname(). Since all callers have to be updated, l2tp_session_find_by_ifname() and l2tp_nl_session_find() are renamed to reflect their new behaviour. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01l2tp: hold session while sending creation notificationsGuillaume Nault1-2/+4
l2tp_session_find() doesn't take any reference on the returned session. Therefore, the session may disappear while sending the notification. Use l2tp_session_get() instead and decrement session's refcount once the notification is sent. Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09net: l2tp: cleanup: remove redundant conditionAsbjørn Sloth Tønnesen1-6/+6
These assignments follow this pattern: unsigned int foo:1; struct nlattr *nla = info->attrs[bar]; if (nla) foo = nla_get_flag(nla); /* expands to: foo = !!nla */ This could be simplified to: if (nla) foo = 1; but lets just remove the condition and use the macro, foo = nla_get_flag(nla); Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09net: l2tp: netlink: l2tp_nl_tunnel_send: set UDP6 checksum flagsAsbjørn Sloth Tønnesen1-0/+10
This patch causes the proper attribute flags to be set, in the case that IPv6 UDP checksums are disabled, so that userspace ie. `ip l2tp show tunnel` knows about it. Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st> Signed-off-by: David S. Miller <davem@davemloft.net>