ec8f24b7 - treewide: Add SPDX license identifier - Makefile/Kconfig

Sun, 19 May 2019 12:07:45 +0000

treewide: Add SPDX license identifier - Makefile/KconfigAdd SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any formThese files fall under the project license, GPL v2 only. The resulting SPDXlicense identifier is: GPL-2.0-onlySigned-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/net/strparser/Makefile

43a0c675 - strparser: Stream parser for messages

Mon, 15 Aug 2016 21:51:01 +0000

strparser: Stream parser for messagesThis patch introduces a utility for parsing application layer protocolmessages in a TCP stream. This is a generalization of the mechanismimplemented of Kernel Connection Multiplexor.The API includes a context structure, a set of callbacks, utilityfunctions, and a data ready function.A stream parser instance is defined by a strparse structure thatis bound to a TCP socket. The function to initialize the structureis: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 lowersocket for strparser to process. This should be called from a data_readycallback 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 tostrp_tcp_data_ready so that all receive indications on the socketgo through the parser. This is assumes that sk_user_data is set tothe 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 parserThe input to parse_msg is an skbuff which contains next message underconstruction. The backend processing of parse_msg will parse theapplication layer protocol headers to determine the length ofthe 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 parserand report and error to userspace. The application must dealwith the error. To handle the error the strparser is unboundfrom the TCP socket. If the error indicates that the streamTCP socket is at recoverable point (ESTRPIPE) then the applicationcan read the TCP socket to process the stream. Once the applicationhas dealt with the exceptions in the stream, it may again bind thesocket to a strparser to continue data operations.Note that ENODATA may be returned to the application. In this caseparse_msg returned -ESTRPIPE, however strparser was unable to maintainsynchronization of the stream (i.e. some of the message in questionwas already read by the parser).strp_pause and strp_unpause are used to provide flow control. Forinstance, if rcv_msg is called but the upper layer can't immediatelyconsume the message it can hold the message and pause strparser.Signed-off-by: Tom Herbert Signed-off-by: David S. Miller List of files: /linux-6.15/net/strparser/Makefile

Changes in Makefile

ec8f24b7 - treewide: Add SPDX license identifier - Makefile/Kconfig

43a0c675 - strparser: Stream parser for messages