lwn.git/net/l2tp/l2tp_ppp.c, branch docs-6.1

net: l2tp: fix clang -Wformat warning

2022-07-08T01:07:01+00:00

When building with clang we encounter this warning: | net/l2tp/l2tp_ppp.c:1557:6: error: format specifies type 'unsigned | short' but the argument has type 'u32' (aka 'unsigned int') | [-Werror,-Wformat] session->nr, session->ns, Both session->nr and session->ns are of type u32. The format specifier previously used is `%hu` which would truncate our unsigned integer from 32 to 16 bits. This doesn't seem like intended behavior, if it is then perhaps we need to consider suppressing the warning with pragma clauses. This patch should get us closer to the goal of enabling the -Wformat flag for Clang builds. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Signed-off-by: Justin Stitt Acked-by: Guillaume Nault Link: https://lore.kernel.org/r/20220706230833.535238-1-justinstitt@google.com Signed-off-by: Jakub Kicinski

net: remove noblock parameter from skb_recv_datagram()

2022-04-06T12:45:26+00:00

skb_recv_datagram() has two parameters 'flags' and 'noblock' that are merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)' As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags' into 'flags' and 'noblock' with finally obsolete bit operations like this: skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc); And this is not even done consistently with the 'flags' parameter. This patch removes the obsolete and costly splitting into two parameters and only performs bit operations when really needed on the caller side. One missing conversion thankfully reported by kernel test robot. I missed to enable kunit tests to build the mctp code. Reported-by: kernel test robot Signed-off-by: Oliver Hartkopp Signed-off-by: David S. Miller

l2tp: Fix spelling mistakes

2021-06-07T21:08:30+00:00

Fix some spelling mistakes in comments: negociated ==> negotiated dont ==> don't Signed-off-by: Zheng Yongjun Signed-off-by: David S. Miller

l2tp: make magic feather checks more useful

2020-09-03T19:19:03+00:00

The l2tp tunnel and session structures contain a "magic feather" field which was originally intended to help trace lifetime bugs in the code. Since the introduction of the shared kernel refcount code in refcount.h, and l2tp's porting to those APIs, we are covered by the refcount code's checks and warnings. Duplicating those checks in the l2tp code isn't useful. However, magic feather checks are still useful to help to detect bugs stemming from misuse/trampling of the sk_user_data pointer in struct sock. The l2tp code makes extensive use of sk_user_data to stash pointers to the tunnel and session structures, and if another subsystem overwrites sk_user_data it's important to detect this. As such, rework l2tp's magic feather checks to focus on validating the tunnel and session data structures when they're extracted from sk_user_data. * Add a new accessor function l2tp_sk_to_tunnel which contains a magic feather check, and is used by l2tp_core and l2tp_ip[6] * Comment l2tp_udp_encap_recv which doesn't use this new accessor function because of the specific nature of the codepath it is called in * Drop l2tp_session_queue_purge's check on the session magic feather: it is called from code which is walking the tunnel session list, and hence doesn't need validation * Drop l2tp_session_free's check on the tunnel magic feather: the intention of this check is covered by refcount.h's reference count sanity checking * Add session magic validation in pppol2tp_ioctl. On failure return -EBADF, which mirrors the approach in pppol2tp_[sg]etsockopt. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller

l2tp: drop net argument from l2tp_tunnel_create

2020-09-03T19:19:03+00:00

The argument is unused, so remove it. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller

l2tp: remove header length param from l2tp_xmit_skb

2020-09-03T19:19:03+00:00

All callers pass the session structure's hdr_len field as the header length parameter to l2tp_xmit_skb. Since we're passing a pointer to the session structure to l2tp_xmit_skb anyway, there's not much point breaking the header length out as a separate argument. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller

l2tp: remove tunnel and session debug flags field

2020-08-22T19:44:37+00:00

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 Signed-off-by: David S. Miller

l2tp: use standard API for warning log messages

2020-08-22T19:44:37+00:00

The l2tp_* log wrappers only emit messages of a given category if the tunnel or session structure has the appropriate flag set in its debug field. Flags default to being unset. For warning messages, this doesn't make a lot of sense since an administrator is likely to want to know about datapath warnings without needing to tweak the debug flags setting for a given tunnel or session instance. Modify l2tp_warn callsites to use pr_warn_ratelimited instead for unconditional output of warning messages. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller

l2tp: remove noisy logging, use appropriate log levels

2020-08-22T19:44:37+00:00

l2tp_ppp in particular had a lot of log messages for tracing [get|set]sockopt calls. These aren't especially useful, so remove these messages. Several log messages flagging error conditions were logged using l2tp_info: they're better off as l2tp_warn. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller

l2tp: don't log data frames

2020-08-22T19:44:37+00:00

l2tp had logging to trace data frame receipt and transmission, including code to dump packet contents. This was originally intended to aid debugging of core l2tp packet handling, but is of limited use now that code is stable. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller