[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 this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef _ZEBRA_STREAM_H
#define _ZEBRA_STREAM_H

#include <pthread.h>

#include "frratomic.h"
#include "mpls.h"
#include "prefix.h"

#ifdef __cplusplus
extern "C" {
#endif

/*
 * 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[0]; /* data pointer */
};

/* First in first out queue structure. */
struct stream_fifo {
	/* lock for mt-safe operations */
	pthread_mutex_t mtx;

	/* number of streams in this fifo */
	atomic_size_t count;
#if defined DEV_BUILD
	atomic_size_t max_count;
#endif

	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)

/* this macro is deprecated, but not slated for removal anytime soon */
#define STREAM_DATA(S)  ((S)->data)

/* 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_inplace(struct stream **sptr, size_t newsize);

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 uint8_t *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 *, uint8_t);
extern int stream_putc_at(struct stream *, size_t, uint8_t);
extern int stream_putw(struct stream *, uint16_t);
extern int stream_putw_at(struct stream *, size_t, uint16_t);
extern int stream_put3(struct stream *, uint32_t);
extern int stream_put3_at(struct stream *, size_t, uint32_t);
extern int stream_putl(struct stream *, uint32_t);
extern int stream_putl_at(struct stream *, size_t, uint32_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 *, uint32_t);
extern int stream_put_in_addr(struct stream *s, const struct in_addr *addr);
extern int stream_put_in_addr_at(struct stream *s, size_t putp,
				 const struct in_addr *addr);
extern int stream_put_in6_addr_at(struct stream *s, size_t putp,
				  const struct in6_addr *addr);
extern int stream_put_prefix_addpath(struct stream *s,
				     const struct prefix *p,
				     int addpath_encode,
				     uint32_t addpath_tx_id);
extern int stream_put_prefix(struct stream *s, const struct prefix *p);
extern int stream_put_labeled_prefix(struct stream *, struct prefix *,
				     mpls_label_t *, int addpath_encode,
				     uint32_t addpath_tx_id);
extern void stream_get(void *, struct stream *, size_t);
extern bool stream_get2(void *data, struct stream *s, size_t size);
extern void stream_get_from(void *, struct stream *, size_t, size_t);
extern uint8_t stream_getc(struct stream *);
extern bool stream_getc2(struct stream *s, uint8_t *byte);
extern uint8_t stream_getc_from(struct stream *, size_t);
extern uint16_t stream_getw(struct stream *);
extern bool stream_getw2(struct stream *s, uint16_t *word);
extern uint16_t stream_getw_from(struct stream *, size_t);
extern uint32_t stream_get3(struct stream *);
extern uint32_t stream_get3_from(struct stream *, size_t);
extern uint32_t stream_getl(struct stream *);
extern bool stream_getl2(struct stream *s, uint32_t *l);
extern uint32_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 uint32_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 uint8_t *stream_pnt(struct stream *);

/*
 * Operations on struct stream_fifo.
 *
 * Each function has a safe variant, which ensures that the operation performed
 * is atomic with respect to the operations performed by all other safe
 * variants. In other words, the safe variants lock the stream_fifo's mutex
 * before performing their action. These are provided for convenience when
 * using stream_fifo in a multithreaded context, to alleviate the need for the
 * caller to implement their own synchronization around the stream_fifo.
 *
 * The following functions do not have safe variants. The caller must ensure
 * that these operations are performed safely in a multithreaded context:
 * - stream_fifo_new
 * - stream_fifo_free
 */

/*
 * Create a new stream_fifo.
 *
 * Returns:
 *    newly created stream_fifo
 */
extern struct stream_fifo *stream_fifo_new(void);

/*
 * Push a stream onto a stream_fifo.
 *
 * fifo
 *    the stream_fifo to push onto
 *
 * s
 *    the stream to push onto the stream_fifo
 */
extern void stream_fifo_push(struct stream_fifo *fifo, struct stream *s);
extern void stream_fifo_push_safe(struct stream_fifo *fifo, struct stream *s);

/*
 * Pop a stream off a stream_fifo.
 *
 * fifo
 *    the stream_fifo to pop from
 *
 * Returns:
 *    the next stream in the stream_fifo
 */
extern struct stream *stream_fifo_pop(struct stream_fifo *fifo);
extern struct stream *stream_fifo_pop_safe(struct stream_fifo *fifo);

/*
 * Retrieve the next stream from a stream_fifo without popping it.
 *
 * fifo
 *    the stream_fifo to operate on
 *
 * Returns:
 *    the next stream that would be returned from stream_fifo_pop
 */
extern struct stream *stream_fifo_head(struct stream_fifo *fifo);
extern struct stream *stream_fifo_head_safe(struct stream_fifo *fifo);

/*
 * Remove all streams from a stream_fifo.
 *
 * fifo
 *    the stream_fifo to clean
 */
extern void stream_fifo_clean(struct stream_fifo *fifo);
extern void stream_fifo_clean_safe(struct stream_fifo *fifo);

/*
 * Retrieve number of streams on a stream_fifo.
 *
 * fifo
 *    the stream_fifo to retrieve the count for
 *
 * Returns:
 *    the number of streams on the stream_fifo
 */
extern size_t stream_fifo_count_safe(struct stream_fifo *fifo);

/*
 * Free a stream_fifo.
 *
 * Calls stream_fifo_clean, then deinitializes the stream_fifo and frees it.
 *
 * fifo
 *    the stream_fifo to free
 */
extern void stream_fifo_free(struct stream_fifo *fifo);

/* This is here because "<< 24" is particularly problematic in C.
 * This is because the left operand of << is integer-promoted, which means
 * an uint8_t gets converted into a *signed* int.  Shifting into the sign
 * bit of a signed int is theoretically undefined behaviour, so - the left
 * operand needs to be cast to unsigned.
 *
 * This is not a problem for 16- or 8-bit values (they don't reach the sign
 * bit), for 64-bit values (you need to cast them anyway), and neither for
 * encoding (because it's downcasted.)
 */
static inline uint8_t *ptr_get_be32(uint8_t *ptr, uint32_t *out)
{
	uint32_t tmp;
	memcpy(&tmp, ptr, sizeof(tmp));
	*out = ntohl(tmp);
	return ptr + 4;
}

/*
 * so Normal stream_getX functions assert.  Which is anathema
 * to keeping a daemon up and running when something goes south
 * Provide a stream_getX2 functions that do not assert.
 * In addition provide these macro's that upon failure
 * goto stream_failure.  This is modeled upon some NL_XX
 * macros in the linux kernel.
 *
 * This change allows for proper memory freeing
 * after we've detected an error.
 *
 * In the future we will be removing the assert in
 * the stream functions but we need a transition
 * plan.
 */
#define STREAM_GETC(S, P)                                                      \
	do {                                                                   \
		uint8_t _pval;                                                 \
		if (!stream_getc2((S), &_pval))                                \
			goto stream_failure;                                   \
		(P) = _pval;                                                   \
	} while (0)

#define STREAM_GETW(S, P)                                                      \
	do {                                                                   \
		uint16_t _pval;                                                \
		if (!stream_getw2((S), &_pval))                                \
			goto stream_failure;                                   \
		(P) = _pval;                                                   \
	} while (0)

#define STREAM_GETL(S, P)                                                      \
	do {                                                                   \
		uint32_t _pval;                                                \
		if (!stream_getl2((S), &_pval))                                \
			goto stream_failure;                                   \
		(P) = _pval;                                                   \
	} while (0)

#define STREAM_GET(P, STR, SIZE)                                               \
	do {                                                                   \
		if (!stream_get2((P), (STR), (SIZE)))                          \
			goto stream_failure;                                   \
	} while (0)

#ifdef __cplusplus
}
#endif

#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	*
896014f4 DL	17	* You should have received a copy of the GNU General Public License along
	18	* with this program; see the file COPYING; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
718e3744	20	*/
	21
	22	#ifndef _ZEBRA_STREAM_H
	23	#define _ZEBRA_STREAM_H
	24
363e24c6 QY	25	#include <pthread.h>
	26
	27	#include "frratomic.h"
9bedbb1e	28	#include "mpls.h"
02ff83c5	29	#include "prefix.h"
02ff83c5	30
5e244469 RW	31	#ifdef __cplusplus
	32	extern "C" {
	33	#endif
	34
050c013a	35	/*
	36	* A stream is an arbitrary buffer, whose contents generally are assumed to
	37	* be in network order.
	38	*
	39	* A stream has the following attributes associated with it:
	40	*
	41	* - size: the allocated, invariant size of the buffer.
	42	*
	43	* - getp: the get position marker, denoting the offset in the stream where
	44	* the next read (or 'get') will be from. This getp marker is
	45	* automatically adjusted when data is read from the stream, the
	46	* user may also manipulate this offset as they wish, within limits
	47	* (see below)
	48	*
	49	* - endp: the end position marker, denoting the offset in the stream where
	50	* valid data ends, and if the user attempted to write (or
	51	* 'put') data where that data would be written (or 'put') to.
	52	*
	53	* These attributes are all size_t values.
	54	*
	55	* Constraints:
	56	*
	57	* 1. getp can never exceed endp
	58	*
	59	* - hence if getp is equal to endp, there is no more valid data that can be
	60	* gotten from the stream (though, the user may reposition getp to earlier in
	61	* the stream, if they wish).
	62	*
	63	* 2. endp can never exceed size
	64	*
	65	* - hence, if endp is equal to size, then the stream is full, and no more
	66	* data can be written to the stream.
	67	*
	68	* In other words the following must always be true, and the stream
	69	* abstraction is allowed internally to assert that the following property
	70	* holds true for a stream, as and when it wishes:
	71	*
	72	* getp <= endp <= size
	73	*
	74	* It is the users responsibility to ensure this property is never violated.
	75	*
	76	* A stream therefore can be thought of like this:
	77	*
	78	* ---------------------------------------------------
	79	* \|XXXXXXXXXXXXXXXXXXXXXXXX \|
	80	* ---------------------------------------------------
	81	* ^ ^ ^
	82	* getp endp size
	83	*
	84	* This shows a stream containing data (shown as 'X') up to the endp offset.
	85	* The stream is empty from endp to size. Without adjusting getp, there are
	86	* still endp-getp bytes of valid data to be read from the stream.
	87	*
d62a17ae	88	* Methods are provided to get and put to/from the stream, as well as
050c013a	89	* retrieve the values of the 3 markers and manipulate the getp marker.
	90	*
	91	* Note:
	92	* At the moment, newly allocated streams are zero filled. Hence, one can
	93	* use stream_forward_endp() to effectively create arbitrary zero-fill
	94	* padding. However, note that stream_reset() does not zero-out the
	95	* stream. This property should not be relied upon.
0dab9303	96	*
	97	* Best practice is to use stream_put (<stream *>, NULL, <size>) to zero out
	98	* any part of a stream which isn't otherwise written to.
050c013a	99	*/
050c013a	100
718e3744	101	/* Stream buffer. */
d62a17ae	102	struct stream {
	103	struct stream *next;
	104
de75223e DS	105	/*
de75223e DS	106	* Remainder is *private* to stream
d62a17ae	107	* direct access is frowned upon!
	108	* Use the appropriate functions/macros
	109	*/
de75223e DS	110	size_t getp; /* next get position */
	111	size_t endp; /* last valid data position */
	112	size_t size; /* size of data segment */
	113	unsigned char data[0]; /* data pointer */
718e3744	114	};
	115
	116	/* First in first out queue structure. */
d62a17ae	117	struct stream_fifo {
363e24c6 QY	118	/* lock for mt-safe operations */
	119	pthread_mutex_t mtx;
	120
	121	/* number of streams in this fifo */
c8a65463	122	atomic_size_t count;
03ed85a6	123	#if defined DEV_BUILD
c8a65463	124	atomic_size_t max_count;
03ed85a6	125	#endif
718e3744	126
d62a17ae	127	struct stream *head;
d62a17ae	128	struct stream *tail;
718e3744	129	};
	130
	131	/* Utility macros. */
718e3744	132	#define STREAM_SIZE(S) ((S)->size)
d62a17ae	133	/* number of bytes which can still be written */
050c013a	134	#define STREAM_WRITEABLE(S) ((S)->size - (S)->endp)
d62a17ae	135	/* number of bytes still to be read */
050c013a	136	#define STREAM_READABLE(S) ((S)->endp - (S)->getp)
050c013a	137
d62a17ae	138	#define STREAM_CONCAT_REMAIN(S1, S2, size) ((size) - (S1)->endp - (S2)->endp)
8c71e481	139
2d34fb80 QY	140	/* this macro is deprecated, but not slated for removal anytime soon */
	141	#define STREAM_DATA(S) ((S)->data)
	142
d62a17ae	143	/* Stream prototypes.
4b201d46	144	* For stream_{put,get}S, the S suffix mean:
	145	*
	146	* c: character (unsigned byte)
	147	* w: word (two bytes)
	148	* l: long (two words)
	149	* q: quad (four words)
	150	*/
d62a17ae	151	extern struct stream *stream_new(size_t);
	152	extern void stream_free(struct stream *);
	153	extern struct stream stream_copy(struct stream , struct stream *src);
	154	extern struct stream stream_dup(struct stream );
43888669	155
43888669 DS	156	extern size_t stream_resize_inplace(struct stream **sptr, size_t newsize);
43888669 DS	157
d62a17ae	158	extern size_t stream_get_getp(struct stream *);
	159	extern size_t stream_get_endp(struct stream *);
	160	extern size_t stream_get_size(struct stream *);
d7c0a89a	161	extern uint8_t stream_get_data(struct stream );
8cc4198f	162
8c71e481 PM	163	/**
	164	* Create a new stream structure; copy offset bytes from s1 to the new
	165	* stream; copy s2 data to the new stream; copy rest of s1 data to the
	166	* new stream.
	167	*/
	168	extern struct stream stream_dupcat(struct stream s1, struct stream *s2,
	169	size_t offset);
	170
d62a17ae	171	extern void stream_set_getp(struct stream *, size_t);
	172	extern void stream_set_endp(struct stream *, size_t);
	173	extern void stream_forward_getp(struct stream *, size_t);
	174	extern void stream_forward_endp(struct stream *, size_t);
8cc4198f	175
8cc4198f	176	/* steam_put: NULL source zeroes out size_t bytes of stream */
d62a17ae	177	extern void stream_put(struct stream , const void , size_t);
d7c0a89a QY	178	extern int stream_putc(struct stream *, uint8_t);
	179	extern int stream_putc_at(struct stream *, size_t, uint8_t);
	180	extern int stream_putw(struct stream *, uint16_t);
	181	extern int stream_putw_at(struct stream *, size_t, uint16_t);
	182	extern int stream_put3(struct stream *, uint32_t);
	183	extern int stream_put3_at(struct stream *, size_t, uint32_t);
	184	extern int stream_putl(struct stream *, uint32_t);
	185	extern int stream_putl_at(struct stream *, size_t, uint32_t);
d62a17ae	186	extern int stream_putq(struct stream *, uint64_t);
d62a17ae	187	extern int stream_putq_at(struct stream *, size_t, uint64_t);
d7c0a89a	188	extern int stream_put_ipv4(struct stream *, uint32_t);
d3d77ec4 MS	189	extern int stream_put_in_addr(struct stream s, const struct in_addr addr);
	190	extern int stream_put_in_addr_at(struct stream *s, size_t putp,
	191	const struct in_addr *addr);
	192	extern int stream_put_in6_addr_at(struct stream *s, size_t putp,
	193	const struct in6_addr *addr);
	194	extern int stream_put_prefix_addpath(struct stream *s,
	195	const struct prefix *p,
d62a17ae	196	int addpath_encode,
d7c0a89a	197	uint32_t addpath_tx_id);
d3d77ec4	198	extern int stream_put_prefix(struct stream s, const struct prefix p);
d62a17ae	199	extern int stream_put_labeled_prefix(struct stream , struct prefix ,
ec15e1b5 QY	200	mpls_label_t *, int addpath_encode,
ec15e1b5 QY	201	uint32_t addpath_tx_id);
d62a17ae	202	extern void stream_get(void , struct stream , size_t);
051cc28c	203	extern bool stream_get2(void data, struct stream s, size_t size);
d62a17ae	204	extern void stream_get_from(void , struct stream , size_t, size_t);
d7c0a89a QY	205	extern uint8_t stream_getc(struct stream *);
	206	extern bool stream_getc2(struct stream s, uint8_t byte);
	207	extern uint8_t stream_getc_from(struct stream *, size_t);
	208	extern uint16_t stream_getw(struct stream *);
051cc28c	209	extern bool stream_getw2(struct stream s, uint16_t word);
d7c0a89a QY	210	extern uint16_t stream_getw_from(struct stream *, size_t);
	211	extern uint32_t stream_get3(struct stream *);
	212	extern uint32_t stream_get3_from(struct stream *, size_t);
	213	extern uint32_t stream_getl(struct stream *);
051cc28c	214	extern bool stream_getl2(struct stream s, uint32_t l);
d7c0a89a	215	extern uint32_t stream_getl_from(struct stream *, size_t);
d62a17ae	216	extern uint64_t stream_getq(struct stream *);
d62a17ae	217	extern uint64_t stream_getq_from(struct stream *, size_t);
d7c0a89a	218	extern uint32_t stream_get_ipv4(struct stream *);
718e3744	219
16f1b9ee	220	/* IEEE-754 floats */
d62a17ae	221	extern float stream_getf(struct stream *);
	222	extern double stream_getd(struct stream *);
	223	extern int stream_putf(struct stream *, float);
	224	extern int stream_putd(struct stream *, double);
16f1b9ee	225
718e3744	226	#undef stream_read
718e3744	227	#undef stream_write
262feb1a	228
d62a17ae	229	/* Deprecated: assumes blocking I/O. Will be removed.
262feb1a	230	Use stream_read_try instead. */
d62a17ae	231	extern int stream_read(struct stream *, int, size_t);
262feb1a	232
262feb1a	233	/* Read up to size bytes into the stream.
	234	Return code:
	235	>0: number of bytes read
	236	0: end-of-file
	237	-1: fatal error
	238	-2: transient error, should retry later (i.e. EAGAIN or EINTR)
	239	This is suitable for use with non-blocking file descriptors.
	240	*/
	241	extern ssize_t stream_read_try(struct stream *s, int fd, size_t size);
	242
d62a17ae	243	extern ssize_t stream_recvmsg(struct stream s, int fd, struct msghdr ,
	244	int flags, size_t size);
	245	extern ssize_t stream_recvfrom(struct stream *s, int fd, size_t len, int flags,
	246	struct sockaddr from, socklen_t fromlen);
	247	extern size_t stream_write(struct stream , const void , size_t);
718e3744	248
8cc4198f	249	/* reset the stream. See Note above */
d62a17ae	250	extern void stream_reset(struct stream *);
	251	extern int stream_flush(struct stream *, int);
	252	extern int stream_empty(struct stream ); / is the stream empty? */
050c013a	253
050c013a	254	/* deprecated */
d7c0a89a	255	extern uint8_t stream_pnt(struct stream );
718e3744	256
363e24c6 QY	257	/*
	258	* Operations on struct stream_fifo.
	259	*
	260	* Each function has a safe variant, which ensures that the operation performed
	261	* is atomic with respect to the operations performed by all other safe
	262	* variants. In other words, the safe variants lock the stream_fifo's mutex
	263	* before performing their action. These are provided for convenience when
	264	* using stream_fifo in a multithreaded context, to alleviate the need for the
	265	* caller to implement their own synchronization around the stream_fifo.
	266	*
	267	* The following functions do not have safe variants. The caller must ensure
	268	* that these operations are performed safely in a multithreaded context:
	269	* - stream_fifo_new
	270	* - stream_fifo_free
	271	*/
	272
	273	/*
	274	* Create a new stream_fifo.
	275	*
	276	* Returns:
	277	* newly created stream_fifo
	278	*/
d62a17ae	279	extern struct stream_fifo *stream_fifo_new(void);
363e24c6 QY	280
	281	/*
	282	* Push a stream onto a stream_fifo.
	283	*
	284	* fifo
	285	* the stream_fifo to push onto
	286	*
	287	* s
	288	* the stream to push onto the stream_fifo
	289	*/
d62a17ae	290	extern void stream_fifo_push(struct stream_fifo fifo, struct stream s);
363e24c6 QY	291	extern void stream_fifo_push_safe(struct stream_fifo fifo, struct stream s);
	292
	293	/*
	294	* Pop a stream off a stream_fifo.
	295	*
	296	* fifo
	297	* the stream_fifo to pop from
	298	*
	299	* Returns:
	300	* the next stream in the stream_fifo
	301	*/
d62a17ae	302	extern struct stream stream_fifo_pop(struct stream_fifo fifo);
363e24c6 QY	303	extern struct stream stream_fifo_pop_safe(struct stream_fifo fifo);
	304
	305	/*
	306	* Retrieve the next stream from a stream_fifo without popping it.
	307	*
	308	* fifo
	309	* the stream_fifo to operate on
	310	*
	311	* Returns:
	312	* the next stream that would be returned from stream_fifo_pop
	313	*/
d62a17ae	314	extern struct stream stream_fifo_head(struct stream_fifo fifo);
363e24c6 QY	315	extern struct stream stream_fifo_head_safe(struct stream_fifo fifo);
	316
	317	/*
	318	* Remove all streams from a stream_fifo.
	319	*
	320	* fifo
	321	* the stream_fifo to clean
	322	*/
d62a17ae	323	extern void stream_fifo_clean(struct stream_fifo *fifo);
363e24c6 QY	324	extern void stream_fifo_clean_safe(struct stream_fifo *fifo);
	325
	326	/*
	327	* Retrieve number of streams on a stream_fifo.
	328	*
	329	* fifo
	330	* the stream_fifo to retrieve the count for
	331	*
	332	* Returns:
	333	* the number of streams on the stream_fifo
	334	*/
	335	extern size_t stream_fifo_count_safe(struct stream_fifo *fifo);
	336
	337	/*
	338	* Free a stream_fifo.
	339	*
	340	* Calls stream_fifo_clean, then deinitializes the stream_fifo and frees it.
	341	*
	342	* fifo
	343	* the stream_fifo to free
	344	*/
d62a17ae	345	extern void stream_fifo_free(struct stream_fifo *fifo);
718e3744	346
937652c6 DL	347	/* This is here because "<< 24" is particularly problematic in C.
	348	* This is because the left operand of << is integer-promoted, which means
	349	* an uint8_t gets converted into a signed int. Shifting into the sign
	350	* bit of a signed int is theoretically undefined behaviour, so - the left
	351	* operand needs to be cast to unsigned.
	352	*
	353	* This is not a problem for 16- or 8-bit values (they don't reach the sign
	354	* bit), for 64-bit values (you need to cast them anyway), and neither for
	355	* encoding (because it's downcasted.)
	356	*/
	357	static inline uint8_t ptr_get_be32(uint8_t ptr, uint32_t *out)
	358	{
	359	uint32_t tmp;
	360	memcpy(&tmp, ptr, sizeof(tmp));
	361	*out = ntohl(tmp);
	362	return ptr + 4;
	363	}
	364
051cc28c DS	365	/*
	366	* so Normal stream_getX functions assert. Which is anathema
	367	* to keeping a daemon up and running when something goes south
	368	* Provide a stream_getX2 functions that do not assert.
	369	* In addition provide these macro's that upon failure
	370	* goto stream_failure. This is modeled upon some NL_XX
	371	* macros in the linux kernel.
	372	*
	373	* This change allows for proper memory freeing
	374	* after we've detected an error.
	375	*
	376	* In the future we will be removing the assert in
	377	* the stream functions but we need a transition
	378	* plan.
	379	*/
996c9314 LB	380	#define STREAM_GETC(S, P) \
	381	do { \
	382	uint8_t _pval; \
	383	if (!stream_getc2((S), &_pval)) \
	384	goto stream_failure; \
	385	(P) = _pval; \
051cc28c DS	386	} while (0)
051cc28c DS	387
996c9314 LB	388	#define STREAM_GETW(S, P) \
	389	do { \
	390	uint16_t _pval; \
	391	if (!stream_getw2((S), &_pval)) \
	392	goto stream_failure; \
	393	(P) = _pval; \
051cc28c DS	394	} while (0)
051cc28c DS	395
996c9314 LB	396	#define STREAM_GETL(S, P) \
	397	do { \
	398	uint32_t _pval; \
	399	if (!stream_getl2((S), &_pval)) \
	400	goto stream_failure; \
	401	(P) = _pval; \
051cc28c DS	402	} while (0)
051cc28c DS	403
996c9314 LB	404	#define STREAM_GET(P, STR, SIZE) \
	405	do { \
	406	if (!stream_get2((P), (STR), (SIZE))) \
	407	goto stream_failure; \
051cc28c DS	408	} while (0)
051cc28c DS	409
5e244469 RW	410	#ifdef __cplusplus
	411	}
	412	#endif
	413
718e3744	414	#endif /* _ZEBRA_STREAM_H */