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  1. 19 Aug, 2016 15 commits
  3. 18 Aug, 2016 17 commits
  5. 17 Aug, 2016 8 commits
    • David S. Miller's avatar
      Merge branch 'strparser' · 48433419
      David S. Miller authored 
      Tom Herbert says:

====================
strp: Stream parser for messages

This patch set introduces a utility for parsing application layer
protocol messages in a TCP stream. This is a generalization of the
mechanism implemented of Kernel Connection Multiplexor.

This patch set adapts KCM to use the strparser. We expect that kTLS
can use this mechanism also. RDS would probably be another candidate
to use a common stream parsing mechanism.

The API includes a context structure, a set of callbacks, utility
functions, and a data ready function. The callbacks include
a parse_msg function that is called to perform parsing (e.g.
BPF parsing in case of KCM), and a rcv_msg function that is called
when a full message has been completed.

For strparser we specify the return codes from the parser to allow
the backend to indicate that control of the socket should be
transferred back to userspace to handle some exceptions in the
stream: The return values are:

      >0 : indicates length of successfully parsed message
       0  : indicates more data must be received to parse the message
       -ESTRPIPE : current message should not be processed by the
          kernel, return control of the socket to userspace which
          can proceed to read the messages itself
       other < 0 : Error is parsing, give control back to userspace
          assuming that synchronization is lost and the stream
          is unrecoverable (application expected to close TCP socket)

There is one issue I haven't been able to fully resolve. If parse_msg
returns ESTRPIPE (wants control back to userspace) the parser may
already have consumed some bytes of the message. There is no way to
put bytes back into the TCP receive queue and tcp_read_sock does not
allow an easy way to peek messages. In lieu of a better solution, we
return ENODATA on the socket to indicate that the data stream is
unrecoverable (application needs to close socket). This condition
should only happen if an application layer message header is split
across two skbuffs and parsing just the first skbuff wasn't sufficient
to determine the that transfer to userspace is needed.

This patch set contains:

  - strparser implementation
  - changes to kcm to use strparser
  - strparser.txt documentation

v2:
  - Add copyright notice to C files
  - Remove GPL module license from strparser.c
  - Add report of rxpause

v3:
  - Restore GPL module license
  - Use EXPORT_SYMBOL_GPL

v4:
  - Removed unused function, changed another to be static as suggested
    by davem
  - Rewoked data_ready to be called from upper layer, no longer requires
    taking over socket data_ready callback as suggested by Lance Chao

Tested:
  - Ran a KCM thrash test for 24 hours. No behavioral or performance
    differences observed.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      48433419
    • Tom Herbert's avatar
      strparser: Documentation · adcce4d5
      Tom Herbert authored 
      Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      adcce4d5
    • Tom Herbert's avatar
      kcm: Use stream parser · 9b73896a
      Tom Herbert authored 
      Adapt KCM to use the stream parser. This mostly involves removing
the RX handling and setting up the strparser using the interface.
Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9b73896a
    • Tom Herbert's avatar
      strparser: Stream parser for messages · 43a0c675
      Tom Herbert authored 
      This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.

The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.

A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:

int strp_init(struct strparser *strp, struct sock *csk,
              struct strp_callbacks *cb);

csk is the TCP socket being bound to and cb are the parser callbacks.

The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:

void strp_tcp_data_ready(struct strparser *strp);

A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.

There are four callbacks.
 - parse_msg is called to parse the message (returns length or error).
 - rcv_msg is called when a complete message has been received
 - read_sock_done is called when data_ready function exits
 - abort_parser is called to abort the parser

The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:

   >0 : indicates length of successfully parsed message
   0  : indicates more data must be received to parse the message
   -ESTRPIPE : current message should not be processed by the
      kernel, return control of the socket to userspace which
      can proceed to read the messages itself
   other < 0 : Error is parsing, give control back to userspace
      assuming that synchronzation is lost and the stream
      is unrecoverable (application expected to close TCP socket)

In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.

Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).

strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      43a0c675
    • Thierry Reding's avatar
      net: ipconfig: Fix more use after free · d2d371ae
      Thierry Reding authored 
      While commit 9c706a49 ("net: ipconfig: fix use after free") avoids
the use after free, the resulting code still ends up calling both the
ic_setup_if() and ic_setup_routes() after calling ic_close_devs(), and
access to the device is still required.

Move the call to ic_close_devs() to the very end of the function.
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d2d371ae
    • David S. Miller's avatar
      Merge branch 'tc_action-fixes' · b96c22c0
      David S. Miller authored 
      Cong Wang says:

====================
net_sched: tc action fixes and updates

This patchset fixes a few regressions caused by the previous
code refactor and more. Thanks to Jamal for catching them!

Note, patch 3/7 and 4/7 are not strictly necessary for this patchset,
I just want to carry them together.

---
v4: adjust an indention for Jamal
    add two more patches

v3: avoid list for fast path, suggested by Jamal

v2: replace flex_array with regular dynamic array
    keep tcf_action_stats_update() in act_api.h
    fix macro typos found by Amir
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b96c22c0
    • Roman Mashak's avatar
      net_sched: allow flushing tc police actions · b5ac8518
      Roman Mashak authored 
      The act_police uses its own code to walk the
action hashtable, which leads to that we could
not flush standalone tc police actions, so just
switch to tcf_generic_walker() like other actions.

(Joint work from Roman and Cong.)
Signed-off-by: default avatarRoman Mashak <mrv@mojatatu.com>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b5ac8518
    • WANG Cong's avatar
      net_sched: unify the init logic for act_police · 0852e455
      WANG Cong authored 
      Jamal reported a crash when we create a police action
with a specific index, this is because the init logic
is not correct, we should always create one for this
case. Just unify the logic with other tc actions.

Fixes: a03e6fe5 ("act_police: fix a crash during removal")
Reported-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0852e455
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