lwn.git/net/sched/sch_api.c, branch v5.6-rc7

net_sched: walk through all child classes in tc_bind_tclass()

2020-01-27T09:52:46+00:00

In a complex TC class hierarchy like this: tc qdisc add dev eth0 root handle 1:0 cbq bandwidth 100Mbit \ avpkt 1000 cell 8 tc class add dev eth0 parent 1:0 classid 1:1 cbq bandwidth 100Mbit \ rate 6Mbit weight 0.6Mbit prio 8 allot 1514 cell 8 maxburst 20 \ avpkt 1000 bounded tc filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip \ sport 80 0xffff flowid 1:3 tc filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip \ sport 25 0xffff flowid 1:4 tc class add dev eth0 parent 1:1 classid 1:3 cbq bandwidth 100Mbit \ rate 5Mbit weight 0.5Mbit prio 5 allot 1514 cell 8 maxburst 20 \ avpkt 1000 tc class add dev eth0 parent 1:1 classid 1:4 cbq bandwidth 100Mbit \ rate 3Mbit weight 0.3Mbit prio 5 allot 1514 cell 8 maxburst 20 \ avpkt 1000 where filters are installed on qdisc 1:0, so we can't merely search from class 1:1 when creating class 1:3 and class 1:4. We have to walk through all the child classes of the direct parent qdisc. Otherwise we would miss filters those need reverse binding. Fixes: 07d79fc7d94e ("net_sched: add reverse binding for tc class") Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net_sched: fix ops->bind_class() implementations

2020-01-27T09:51:43+00:00

The current implementations of ops->bind_class() are merely searching for classid and updating class in the struct tcf_result, without invoking either of cl_ops->bind_tcf() or cl_ops->unbind_tcf(). This breaks the design of them as qdisc's like cbq use them to count filters too. This is why syzbot triggered the warning in cbq_destroy_class(). In order to fix this, we have to call cl_ops->bind_tcf() and cl_ops->unbind_tcf() like the filter binding path. This patch does so by refactoring out two helper functions __tcf_bind_filter() and __tcf_unbind_filter(), which are lockless and accept a Qdisc pointer, then teaching each implementation to call them correctly. Note, we merely pass the Qdisc pointer as an opaque pointer to each filter, they only need to pass it down to the helper functions without understanding it at all. Fixes: 07d79fc7d94e ("net_sched: add reverse binding for tc class") Reported-and-tested-by: syzbot+0a0596220218fcb603a8@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+63bdb6006961d8c917c6@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net_sched: fix backward compatibility for TCA_KIND

2019-10-08T23:21:58+00:00

Marcelo noticed a backward compatibility issue of TCA_KIND after we move from NLA_STRING to NLA_NUL_STRING, so it is probably too late to change it. Instead, to make everyone happy, we can just insert a NUL to terminate the string with nla_strlcpy() like we do for TC actions. Fixes: 62794fc4fbf5 ("net_sched: add max len check for TCA_KIND") Reported-by: Marcelo Ricardo Leitner Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Reviewed-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski

net_sched: add max len check for TCA_KIND

2019-09-22T02:18:51+00:00

The TCA_KIND attribute is of NLA_STRING which does not check the NUL char. KMSAN reported an uninit-value of TCA_KIND which is likely caused by the lack of NUL. Change it to NLA_NUL_STRING and add a max len too. Fixes: 8b4c3cdd9dd8 ("net: sched: Add policy validation for tc attributes") Reported-and-tested-by: syzbot+618aacd49e8c8b8486bd@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Reviewed-by: David Ahern Acked-by: Jiri Pirko Signed-off-by: Jakub Kicinski

net_sched: check cops->tcf_block in tc_bind_tclass()

2019-09-10T17:28:56+00:00

At least sch_red and sch_tbf don't implement ->tcf_block() while still have a non-zero tc "class". Instead of adding nop implementations to each of such qdisc's, we can just relax the check of cops->tcf_block() in tc_bind_tclass(). They don't support TC filter anyway. Reported-by: syzbot+21b29db13c065852f64b@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 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 as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

netlink: make validation more configurable for future strictness

2019-04-27T21:07:21+00:00

We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

netlink: make nla_nest_start() add NLA_F_NESTED flag

2019-04-27T21:03:44+00:00

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 Acked-by: Jiri Pirko Acked-by: David Ahern Signed-off-by: David S. Miller

net: sched: when clearing NOLOCK, clear TCQ_F_CPUSTATS, too

2019-04-10T19:20:46+00:00

Since stats updating is always consistent with TCQ_F_CPUSTATS flag, we can disable it at qdisc creation time flipping such bit. In my experiments, if the NOLOCK flag is cleared, per CPU stats accounting does not give any measurable performance gain, but it waste some memory. Let's clear TCQ_F_CPUSTATS together with NOLOCK, when enslaving a NOLOCK qdisc to 'lock' one. Use stats update helper inside pfifo_fast, to cope correctly with TCQ_F_CPUSTATS flag change. As a side effect, q.qlen value for any child qdiscs is always consistent for all lock classfull qdiscs. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

net_sched: return correct value for notify functions

2019-03-13T20:48:27+00:00

It is confusing to directly use return value of netlink_send()/ netlink_unicast() as the return value of *notify*, as it may be not error at all. Example: in tc_del_tfilter(), after calling tfilter_del_notify(), it will goto errout if (err). However, the netlink_send()/netlink_unicast() will return positive value even for successful case. So it may not call tcf_chain_tp_remove() and so on to clean up the resource, as a result, resource is leaked. It may be easier to only check the return value of tfilter_del_nofiy(), but it is more clean to correct all related functions. Co-developed-by: Zengmo Gao Signed-off-by: Zhike Wang Acked-by: Cong Wang Signed-off-by: David S. Miller