[mirror_frr.git] / lib / stream.h

/*
 * Packet interface
 * Copyright (C) 1999 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

#ifndef _ZEBRA_STREAM_H
#define _ZEBRA_STREAM_H

#include "prefix.h"

/*
 * A stream is an arbitrary buffer, whose contents generally are assumed to
 * be in network order.
 *
 * A stream has the following attributes associated with it:
 *
 * - size: the allocated, invariant size of the buffer.
 *
 * - getp: the get position marker, denoting the offset in the stream where
 *         the next read (or 'get') will be from. This getp marker is
 *         automatically adjusted when data is read from the stream, the
 *         user may also manipulate this offset as they wish, within limits
 *         (see below)
 *
 * - endp: the end position marker, denoting the offset in the stream where
 *         valid data ends, and if the user attempted to write (or
 *         'put') data where that data would be written (or 'put') to.
 *
 * These attributes are all size_t values.
 *
 * Constraints:
 *
 * 1. getp can never exceed endp
 *
 * - hence if getp is equal to endp, there is no more valid data that can be
 *   gotten from the stream (though, the user may reposition getp to earlier in
 *   the stream, if they wish).
 *
 * 2. endp can never exceed size
 *
 * - hence, if endp is equal to size, then the stream is full, and no more
 *   data can be written to the stream.
 *
 * In other words the following must always be true, and the stream
 * abstraction is allowed internally to assert that the following property
 * holds true for a stream, as and when it wishes:
 *
 *        getp <= endp <= size
 *
 * It is the users responsibility to ensure this property is never violated.
 *
 * A stream therefore can be thought of like this:
 *
 * 	---------------------------------------------------
 * 	|XXXXXXXXXXXXXXXXXXXXXXXX                         |
 * 	---------------------------------------------------
 *               ^               ^                        ^
 *               getp            endp                     size
 *
 * This shows a stream containing data (shown as 'X') up to the endp offset.
 * The stream is empty from endp to size. Without adjusting getp, there are
 * still endp-getp bytes of valid data to be read from the stream.
 *
 * Methods are provided to get and put to/from the stream, as well as 
 * retrieve the values of the 3 markers and manipulate the getp marker.
 *
 * Note:
 * At the moment, newly allocated streams are zero filled. Hence, one can
 * use stream_forward_endp() to effectively create arbitrary zero-fill
 * padding. However, note that stream_reset() does *not* zero-out the
 * stream. This property should **not** be relied upon.
 *
 * Best practice is to use stream_put (<stream *>, NULL, <size>) to zero out
 * any part of a stream which isn't otherwise written to.
 */

/* Stream buffer. */
struct stream
{
  struct stream *next;

  /* Remainder is ***private*** to stream
   * direct access is frowned upon!
   * Use the appropriate functions/macros 
   */
  size_t getp; 		/* next get position */
  size_t endp;		/* last valid data position */
  size_t size;		/* size of data segment */
  unsigned char *data; /* data pointer */
};

/* First in first out queue structure. */
struct stream_fifo
{
  size_t count;

  struct stream *head;
  struct stream *tail;
};

/* Utility macros. */
#define STREAM_SIZE(S)  ((S)->size)
  /* number of bytes which can still be written */
#define STREAM_WRITEABLE(S) ((S)->size - (S)->endp)
  /* number of bytes still to be read */
#define STREAM_READABLE(S) ((S)->endp - (S)->getp)

#define STREAM_CONCAT_REMAIN(S1, S2, size) \
  ((size) - (S1)->endp - (S2)->endp)

/* deprecated macros - do not use in new code */
#define STREAM_PNT(S)   stream_pnt((S))
#define STREAM_DATA(S)  ((S)->data)
#define STREAM_REMAIN(S) STREAM_WRITEABLE((S))

/* Stream prototypes. 
 * For stream_{put,get}S, the S suffix mean:
 *
 * c: character (unsigned byte)
 * w: word (two bytes)
 * l: long (two words)
 * q: quad (four words)
 */
extern struct stream *stream_new (size_t);
extern void stream_free (struct stream *);
extern struct stream * stream_copy (struct stream *, struct stream *src);
extern struct stream *stream_dup (struct stream *);
extern size_t stream_resize (struct stream *, size_t);
extern size_t stream_get_getp (struct stream *);
extern size_t stream_get_endp (struct stream *);
extern size_t stream_get_size (struct stream *);
extern u_char *stream_get_data (struct stream *);

/**
 * Create a new stream structure; copy offset bytes from s1 to the new
 * stream; copy s2 data to the new stream; copy rest of s1 data to the
 * new stream.
 */
extern struct stream *stream_dupcat(struct stream *s1, struct stream *s2,
				    size_t offset);

extern void stream_set_getp (struct stream *, size_t);
extern void stream_set_endp (struct stream *, size_t);
extern void stream_forward_getp (struct stream *, size_t);
extern void stream_forward_endp (struct stream *, size_t);

/* steam_put: NULL source zeroes out size_t bytes of stream */
extern void stream_put (struct stream *, const void *, size_t);
extern int stream_putc (struct stream *, u_char);
extern int stream_putc_at (struct stream *, size_t, u_char);
extern int stream_putw (struct stream *, u_int16_t);
extern int stream_putw_at (struct stream *, size_t, u_int16_t);
extern int stream_put3 (struct stream *, u_int32_t);
extern int stream_put3_at (struct stream *, size_t, u_int32_t);
extern int stream_putl (struct stream *, u_int32_t);
extern int stream_putl_at (struct stream *, size_t, u_int32_t);
extern int stream_putq (struct stream *, uint64_t);
extern int stream_putq_at (struct stream *, size_t, uint64_t);
extern int stream_put_ipv4 (struct stream *, u_int32_t);
extern int stream_put_in_addr (struct stream *, struct in_addr *);
extern int stream_put_in_addr_at (struct stream *, size_t, struct in_addr *);
extern int stream_put_in6_addr_at (struct stream *, size_t, struct in6_addr *);
extern int stream_put_prefix_addpath (struct stream *, struct prefix *,
                                      int addpath_encode,
                                      u_int32_t addpath_tx_id);
extern int stream_put_prefix (struct stream *, struct prefix *);

extern void stream_get (void *, struct stream *, size_t);
extern void stream_get_from (void *, struct stream *, size_t, size_t);
extern u_char stream_getc (struct stream *);
extern u_char stream_getc_from (struct stream *, size_t);
extern u_int16_t stream_getw (struct stream *);
extern u_int16_t stream_getw_from (struct stream *, size_t);
extern u_int32_t stream_get3 (struct stream *);
extern u_int32_t stream_get3_from (struct stream *, size_t);
extern u_int32_t stream_getl (struct stream *);
extern u_int32_t stream_getl_from (struct stream *, size_t);
extern uint64_t stream_getq (struct stream *);
extern uint64_t stream_getq_from (struct stream *, size_t);
extern u_int32_t stream_get_ipv4 (struct stream *);

/* IEEE-754 floats */
extern float stream_getf (struct stream *);
extern double stream_getd (struct stream *);
extern int stream_putf (struct stream *, float);
extern int stream_putd (struct stream *, double);

#undef stream_read
#undef stream_write

/* Deprecated: assumes blocking I/O.  Will be removed. 
   Use stream_read_try instead.  */
extern int stream_read (struct stream *, int, size_t);

/* Read up to size bytes into the stream.
   Return code:
     >0: number of bytes read
     0: end-of-file
     -1: fatal error
     -2: transient error, should retry later (i.e. EAGAIN or EINTR)
   This is suitable for use with non-blocking file descriptors.
 */
extern ssize_t stream_read_try(struct stream *s, int fd, size_t size);

extern ssize_t stream_recvmsg (struct stream *s, int fd, struct msghdr *,
                               int flags, size_t size);
extern ssize_t stream_recvfrom (struct stream *s, int fd, size_t len, 
                                int flags, struct sockaddr *from, 
                                socklen_t *fromlen);
extern size_t stream_write (struct stream *, const void *, size_t);

/* reset the stream. See Note above */
extern void stream_reset (struct stream *);
extern int stream_flush (struct stream *, int);
extern int stream_empty (struct stream *); /* is the stream empty? */

/* deprecated */
extern u_char *stream_pnt (struct stream *);

/* Stream fifo. */
extern struct stream_fifo *stream_fifo_new (void);
extern void stream_fifo_push (struct stream_fifo *fifo, struct stream *s);
extern struct stream *stream_fifo_pop (struct stream_fifo *fifo);
extern struct stream *stream_fifo_head (struct stream_fifo *fifo);
extern void stream_fifo_clean (struct stream_fifo *fifo);
extern void stream_fifo_free (struct stream_fifo *fifo);

#endif /* _ZEBRA_STREAM_H */
Commit	Line	Data
718e3744	1	/*
	2	* Packet interface
	3	* Copyright (C) 1999 Kunihiro Ishiguro
	4	*
	5	* This file is part of GNU Zebra.
	6	*
	7	* GNU Zebra is free software; you can redistribute it and/or modify it
	8	* under the terms of the GNU General Public License as published by the
	9	* Free Software Foundation; either version 2, or (at your option) any
	10	* later version.
	11	*
	12	* GNU Zebra is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with GNU Zebra; see the file COPYING. If not, write to the Free
	19	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
	20	* 02111-1307, USA.
	21	*/
	22
	23	#ifndef _ZEBRA_STREAM_H
	24	#define _ZEBRA_STREAM_H
	25
02ff83c5	26	#include "prefix.h"
02ff83c5	27
050c013a	28	/*
	29	* A stream is an arbitrary buffer, whose contents generally are assumed to
	30	* be in network order.
	31	*
	32	* A stream has the following attributes associated with it:
	33	*
	34	* - size: the allocated, invariant size of the buffer.
	35	*
	36	* - getp: the get position marker, denoting the offset in the stream where
	37	* the next read (or 'get') will be from. This getp marker is
	38	* automatically adjusted when data is read from the stream, the
	39	* user may also manipulate this offset as they wish, within limits
	40	* (see below)
	41	*
	42	* - endp: the end position marker, denoting the offset in the stream where
	43	* valid data ends, and if the user attempted to write (or
	44	* 'put') data where that data would be written (or 'put') to.
	45	*
	46	* These attributes are all size_t values.
	47	*
	48	* Constraints:
	49	*
	50	* 1. getp can never exceed endp
	51	*
	52	* - hence if getp is equal to endp, there is no more valid data that can be
	53	* gotten from the stream (though, the user may reposition getp to earlier in
	54	* the stream, if they wish).
	55	*
	56	* 2. endp can never exceed size
	57	*
	58	* - hence, if endp is equal to size, then the stream is full, and no more
	59	* data can be written to the stream.
	60	*
	61	* In other words the following must always be true, and the stream
	62	* abstraction is allowed internally to assert that the following property
	63	* holds true for a stream, as and when it wishes:
	64	*
	65	* getp <= endp <= size
	66	*
	67	* It is the users responsibility to ensure this property is never violated.
	68	*
	69	* A stream therefore can be thought of like this:
	70	*
	71	* ---------------------------------------------------
	72	* \|XXXXXXXXXXXXXXXXXXXXXXXX \|
	73	* ---------------------------------------------------
	74	* ^ ^ ^
	75	* getp endp size
	76	*
	77	* This shows a stream containing data (shown as 'X') up to the endp offset.
	78	* The stream is empty from endp to size. Without adjusting getp, there are
	79	* still endp-getp bytes of valid data to be read from the stream.
	80	*
	81	* Methods are provided to get and put to/from the stream, as well as
	82	* retrieve the values of the 3 markers and manipulate the getp marker.
	83	*
	84	* Note:
	85	* At the moment, newly allocated streams are zero filled. Hence, one can
	86	* use stream_forward_endp() to effectively create arbitrary zero-fill
	87	* padding. However, note that stream_reset() does not zero-out the
	88	* stream. This property should not be relied upon.
0dab9303	89	*
	90	* Best practice is to use stream_put (<stream *>, NULL, <size>) to zero out
	91	* any part of a stream which isn't otherwise written to.
050c013a	92	*/
050c013a	93
718e3744	94	/* Stream buffer. */
	95	struct stream
	96	{
	97	struct stream *next;
	98
050c013a	99	/* Remainder is *private* to stream
	100	* direct access is frowned upon!
	101	* Use the appropriate functions/macros
	102	*/
	103	size_t getp; /* next get position */
	104	size_t endp; /* last valid data position */
	105	size_t size; /* size of data segment */
4b201d46	106	unsigned char data; / data pointer */
718e3744	107	};
	108
	109	/* First in first out queue structure. */
	110	struct stream_fifo
	111	{
f2e6c429	112	size_t count;
718e3744	113
	114	struct stream *head;
	115	struct stream *tail;
	116	};
	117
	118	/* Utility macros. */
718e3744	119	#define STREAM_SIZE(S) ((S)->size)
050c013a	120	/* number of bytes which can still be written */
	121	#define STREAM_WRITEABLE(S) ((S)->size - (S)->endp)
	122	/* number of bytes still to be read */
	123	#define STREAM_READABLE(S) ((S)->endp - (S)->getp)
	124
8c71e481 PM	125	#define STREAM_CONCAT_REMAIN(S1, S2, size) \
	126	((size) - (S1)->endp - (S2)->endp)
	127
050c013a	128	/* deprecated macros - do not use in new code */
050c013a	129	#define STREAM_PNT(S) stream_pnt((S))
718e3744	130	#define STREAM_DATA(S) ((S)->data)
050c013a	131	#define STREAM_REMAIN(S) STREAM_WRITEABLE((S))
718e3744	132
4b201d46	133	/* Stream prototypes.
	134	* For stream_{put,get}S, the S suffix mean:
	135	*
	136	* c: character (unsigned byte)
	137	* w: word (two bytes)
	138	* l: long (two words)
	139	* q: quad (four words)
	140	*/
8cc4198f	141	extern struct stream *stream_new (size_t);
8cc4198f	142	extern void stream_free (struct stream *);
dea04441	143	extern struct stream * stream_copy (struct stream , struct stream src);
8cc4198f	144	extern struct stream stream_dup (struct stream );
4b201d46	145	extern size_t stream_resize (struct stream *, size_t);
8cc4198f	146	extern size_t stream_get_getp (struct stream *);
	147	extern size_t stream_get_endp (struct stream *);
	148	extern size_t stream_get_size (struct stream *);
	149	extern u_char stream_get_data (struct stream );
	150
8c71e481 PM	151	/**
	152	* Create a new stream structure; copy offset bytes from s1 to the new
	153	* stream; copy s2 data to the new stream; copy rest of s1 data to the
	154	* new stream.
	155	*/
	156	extern struct stream stream_dupcat(struct stream s1, struct stream *s2,
	157	size_t offset);
	158
8cc4198f	159	extern void stream_set_getp (struct stream *, size_t);
d531050b	160	extern void stream_set_endp (struct stream *, size_t);
8cc4198f	161	extern void stream_forward_getp (struct stream *, size_t);
	162	extern void stream_forward_endp (struct stream *, size_t);
	163
	164	/* steam_put: NULL source zeroes out size_t bytes of stream */
3d52bb80	165	extern void stream_put (struct stream , const void , size_t);
8cc4198f	166	extern int stream_putc (struct stream *, u_char);
	167	extern int stream_putc_at (struct stream *, size_t, u_char);
	168	extern int stream_putw (struct stream *, u_int16_t);
	169	extern int stream_putw_at (struct stream *, size_t, u_int16_t);
d6f4a61d DL	170	extern int stream_put3 (struct stream *, u_int32_t);
d6f4a61d DL	171	extern int stream_put3_at (struct stream *, size_t, u_int32_t);
8cc4198f	172	extern int stream_putl (struct stream *, u_int32_t);
8cc4198f	173	extern int stream_putl_at (struct stream *, size_t, u_int32_t);
4b201d46	174	extern int stream_putq (struct stream *, uint64_t);
4b201d46	175	extern int stream_putq_at (struct stream *, size_t, uint64_t);
8cc4198f	176	extern int stream_put_ipv4 (struct stream *, u_int32_t);
8cc4198f	177	extern int stream_put_in_addr (struct stream , struct in_addr );
3f9c7369 DS	178	extern int stream_put_in_addr_at (struct stream , size_t, struct in_addr );
3f9c7369 DS	179	extern int stream_put_in6_addr_at (struct stream , size_t, struct in6_addr );
adbac85e DW	180	extern int stream_put_prefix_addpath (struct stream , struct prefix ,
	181	int addpath_encode,
	182	u_int32_t addpath_tx_id);
8cc4198f	183	extern int stream_put_prefix (struct stream , struct prefix );
	184
	185	extern void stream_get (void , struct stream , size_t);
3f9c7369	186	extern void stream_get_from (void , struct stream , size_t, size_t);
8cc4198f	187	extern u_char stream_getc (struct stream *);
	188	extern u_char stream_getc_from (struct stream *, size_t);
	189	extern u_int16_t stream_getw (struct stream *);
	190	extern u_int16_t stream_getw_from (struct stream *, size_t);
d6f4a61d DL	191	extern u_int32_t stream_get3 (struct stream *);
d6f4a61d DL	192	extern u_int32_t stream_get3_from (struct stream *, size_t);
8cc4198f	193	extern u_int32_t stream_getl (struct stream *);
8cc4198f	194	extern u_int32_t stream_getl_from (struct stream *, size_t);
4b201d46	195	extern uint64_t stream_getq (struct stream *);
4b201d46	196	extern uint64_t stream_getq_from (struct stream *, size_t);
8cc4198f	197	extern u_int32_t stream_get_ipv4 (struct stream *);
718e3744	198
16f1b9ee OD	199	/* IEEE-754 floats */
	200	extern float stream_getf (struct stream *);
	201	extern double stream_getd (struct stream *);
	202	extern int stream_putf (struct stream *, float);
	203	extern int stream_putd (struct stream *, double);
	204
718e3744	205	#undef stream_read
718e3744	206	#undef stream_write
262feb1a	207
	208	/* Deprecated: assumes blocking I/O. Will be removed.
	209	Use stream_read_try instead. */
8cc4198f	210	extern int stream_read (struct stream *, int, size_t);
262feb1a	211
262feb1a	212	/* Read up to size bytes into the stream.
	213	Return code:
	214	>0: number of bytes read
	215	0: end-of-file
	216	-1: fatal error
	217	-2: transient error, should retry later (i.e. EAGAIN or EINTR)
	218	This is suitable for use with non-blocking file descriptors.
	219	*/
	220	extern ssize_t stream_read_try(struct stream *s, int fd, size_t size);
	221
0dab9303	222	extern ssize_t stream_recvmsg (struct stream s, int fd, struct msghdr ,
8cc4198f	223	int flags, size_t size);
	224	extern ssize_t stream_recvfrom (struct stream *s, int fd, size_t len,
	225	int flags, struct sockaddr *from,
	226	socklen_t *fromlen);
3d52bb80	227	extern size_t stream_write (struct stream , const void , size_t);
718e3744	228
8cc4198f	229	/* reset the stream. See Note above */
	230	extern void stream_reset (struct stream *);
	231	extern int stream_flush (struct stream *, int);
	232	extern int stream_empty (struct stream ); / is the stream empty? */
050c013a	233
050c013a	234	/* deprecated */
8cc4198f	235	extern u_char stream_pnt (struct stream );
718e3744	236
718e3744	237	/* Stream fifo. */
8cc4198f	238	extern struct stream_fifo *stream_fifo_new (void);
	239	extern void stream_fifo_push (struct stream_fifo fifo, struct stream s);
	240	extern struct stream stream_fifo_pop (struct stream_fifo fifo);
	241	extern struct stream stream_fifo_head (struct stream_fifo fifo);
	242	extern void stream_fifo_clean (struct stream_fifo *fifo);
	243	extern void stream_fifo_free (struct stream_fifo *fifo);
718e3744	244
718e3744	245	#endif /* _ZEBRA_STREAM_H */