docs: networking: convert strparser.txt to ReST

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/index.rst

@@ -104,6 +104,7 @@ Contents:
    secid
    seg6-sysctl
    skfp
+   strparser
 
 .. only::  subproject and html
 

Documentation/networking/strparser.rst

@@ -1,4 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================
 Stream Parser (strparser)
+=========================
 
 Introduction
 ============
@@ -34,6 +38,8 @@ that is called when a full message has been completed.
 Functions
 =========
 
+     ::
+
 	strp_init(struct strparser *strp, struct sock *sk,
 		const struct strp_callbacks *cb)
 
@@ -43,15 +49,21 @@ strp_init(struct strparser *strp, struct sock *sk,
      callback mode; in general mode this is set to NULL. Callbacks
      are called by the stream parser (the callbacks are listed below).
 
+     ::
+
 	void strp_pause(struct strparser *strp)
 
      Temporarily pause a stream parser. Message parsing is suspended
      and no new messages are delivered to the upper layer.
 
+     ::
+
 	void strp_unpause(struct strparser *strp)
 
      Unpause a paused stream parser.
 
+     ::
+
 	void strp_stop(struct strparser *strp);
 
      strp_stop is called to completely stop stream parser operations.
@@ -59,12 +71,16 @@ void strp_stop(struct strparser *strp);
      error, and it is called from the upper layer to stop parsing
      operations.
 
+     ::
+
 	void strp_done(struct strparser *strp);
 
      strp_done is called to release any resources held by the stream
      parser instance. This must be called after the stream processor
      has been stopped.
 
+     ::
+
 	int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
 			 unsigned int orig_offset, size_t orig_len,
 			 size_t max_msg_size, long timeo)
@@ -75,6 +91,8 @@ int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
     consume the sk_buff. max_msg_size is maximum size the stream
     parser will parse. timeo is timeout for completing a message.
 
+    ::
+
 	void strp_data_ready(struct strparser *strp);
 
     The upper layer calls strp_tcp_data_ready when data is ready on
@@ -83,6 +101,8 @@ void strp_data_ready(struct strparser *strp);
     maximum messages size is the limit of the receive socket
     buffer and message timeout is the receive timeout for the socket.
 
+    ::
+
 	void strp_check_rcv(struct strparser *strp);
 
     strp_check_rcv is called to check for new messages on the socket.
@@ -94,6 +114,8 @@ Callbacks
 
 There are six callbacks:
 
+    ::
+
 	int (*parse_msg)(struct strparser *strp, struct sk_buff *skb);
 
     parse_msg is called to determine the length of the next message
@@ -107,14 +129,16 @@ int (*parse_msg)(struct strparser *strp, struct sk_buff *skb);
 
     The return values of this function 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
+    =========    ===========================================================
+    >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 in parsing, give control back to userspace
+    other < 0    Error in parsing, give control back to userspace
 		 assuming that synchronization is lost and the stream
 		 is unrecoverable (application expected to close TCP socket)
+    =========    ===========================================================
 
     In the case that an error is returned (return value is less than
     zero) and the parser is in receive callback mode, then it will set
@@ -123,6 +147,8 @@ int (*parse_msg)(struct strparser *strp, struct sk_buff *skb);
     the current message, then the error set on the attached socket is
     ENODATA since the stream is unrecoverable in that case.
 
+    ::
+
 	void (*lock)(struct strparser *strp)
 
     The lock callback is called to lock the strp structure when
@@ -131,6 +157,8 @@ void (*lock)(struct strparser *strp)
     function is to lock_sock for the associated socket. In general
     mode the callback must be set appropriately.
 
+    ::
+
 	void (*unlock)(struct strparser *strp)
 
     The unlock callback is called to release the lock obtained
@@ -138,6 +166,8 @@ void (*unlock)(struct strparser *strp)
     function is release_sock for the associated socket. In general
     mode the callback must be set appropriately.
 
+    ::
+
 	void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb);
 
     rcv_msg is called when a full message has been received and
@@ -152,6 +182,8 @@ void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb);
     the length of the message. skb->len - offset may be greater
     then full_len since strparser does not trim the skb.
 
+    ::
+
 	int (*read_sock_done)(struct strparser *strp, int err);
 
      read_sock_done is called when the stream parser is done reading
@@ -160,6 +192,8 @@ int (*read_sock_done)(struct strparser *strp, int err);
      to occur when exiting the loop. If the callback is not set (NULL
      in strp_init) a default function is used.
 
+     ::
+
 	void (*abort_parser)(struct strparser *strp, int err);
 
      This function is called when stream parser encounters an error
@@ -204,4 +238,3 @@ Author
 ======
 
 Tom Herbert (tom@quantonium.net)
-