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>
strp_unpause queues strp_work in order to parse any messages that
arrived while the strparser was paused. However, the process invoking
strp_unpause could eagerly parse a buffered message itself if it held
the sock lock.
__strp_unpause is an alternative to strp_pause that avoids the scheduling
overhead that results when a receiving thread unpauses the strparser
and waits for the next message to be delivered by the workqueue thread.
This patch more than doubled the IOPS achieved in a benchmark of NBD
traffic encrypted using ktls.
Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sock lock may be taken in the message timer function which is a
problem since timers run in BH. Instead of timers use delayed_work.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: bbb03029a8 ("strparser: Generalize strparser")
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Generalize strparser from more than just being used in conjunction
with read_sock. strparser will also be used in the send path with
zero proxy. The primary change is to create strp_process function
that performs the critical processing on skbs. The documentation
is also updated to reflect the new uses.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
kcm and strparser need to work with any type of stream socket not just
TCP. Eliminate references to TCP and call generic proto_ops functions of
read_sock and peek_len. Also in strp_init check if the socket support
the proto_ops read_sock and peek_len.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the upper layer unpauses a stream parser connection we need to
queue rx_work to make sure no events are missed.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
