[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"

/*
 * 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 *);

#if CONFDATE > 20190821
CPP_NOTICE("lib: time to remove stream_resize_orig")
#endif
extern size_t stream_resize_orig(struct stream *s, size_t newsize);
#define stream_resize stream_resize_orig
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 *, 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,
				     uint32_t addpath_tx_id);
extern int stream_put_prefix(struct stream *, struct prefix *);
extern int stream_put_labeled_prefix(struct stream *, struct prefix *,
				     mpls_label_t *);
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)

#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
050c013a	31	/*
	32	* A stream is an arbitrary buffer, whose contents generally are assumed to
	33	* be in network order.
	34	*
	35	* A stream has the following attributes associated with it:
	36	*
	37	* - size: the allocated, invariant size of the buffer.
	38	*
	39	* - getp: the get position marker, denoting the offset in the stream where
	40	* the next read (or 'get') will be from. This getp marker is
	41	* automatically adjusted when data is read from the stream, the
	42	* user may also manipulate this offset as they wish, within limits
	43	* (see below)
	44	*
	45	* - endp: the end position marker, denoting the offset in the stream where
	46	* valid data ends, and if the user attempted to write (or
	47	* 'put') data where that data would be written (or 'put') to.
	48	*
	49	* These attributes are all size_t values.
	50	*
	51	* Constraints:
	52	*
	53	* 1. getp can never exceed endp
	54	*
	55	* - hence if getp is equal to endp, there is no more valid data that can be
	56	* gotten from the stream (though, the user may reposition getp to earlier in
	57	* the stream, if they wish).
	58	*
	59	* 2. endp can never exceed size
	60	*
	61	* - hence, if endp is equal to size, then the stream is full, and no more
	62	* data can be written to the stream.
	63	*
	64	* In other words the following must always be true, and the stream
	65	* abstraction is allowed internally to assert that the following property
	66	* holds true for a stream, as and when it wishes:
	67	*
	68	* getp <= endp <= size
	69	*
	70	* It is the users responsibility to ensure this property is never violated.
	71	*
	72	* A stream therefore can be thought of like this:
	73	*
	74	* ---------------------------------------------------
	75	* \|XXXXXXXXXXXXXXXXXXXXXXXX \|
	76	* ---------------------------------------------------
	77	* ^ ^ ^
	78	* getp endp size
	79	*
	80	* This shows a stream containing data (shown as 'X') up to the endp offset.
	81	* The stream is empty from endp to size. Without adjusting getp, there are
	82	* still endp-getp bytes of valid data to be read from the stream.
	83	*
d62a17ae	84	* Methods are provided to get and put to/from the stream, as well as
050c013a	85	* retrieve the values of the 3 markers and manipulate the getp marker.
	86	*
	87	* Note:
	88	* At the moment, newly allocated streams are zero filled. Hence, one can
	89	* use stream_forward_endp() to effectively create arbitrary zero-fill
	90	* padding. However, note that stream_reset() does not zero-out the
	91	* stream. This property should not be relied upon.
0dab9303	92	*
	93	* Best practice is to use stream_put (<stream *>, NULL, <size>) to zero out
	94	* any part of a stream which isn't otherwise written to.
050c013a	95	*/
050c013a	96
718e3744	97	/* Stream buffer. */
d62a17ae	98	struct stream {
	99	struct stream *next;
	100
de75223e DS	101	/*
de75223e DS	102	* Remainder is *private* to stream
d62a17ae	103	* direct access is frowned upon!
	104	* Use the appropriate functions/macros
	105	*/
de75223e DS	106	size_t getp; /* next get position */
	107	size_t endp; /* last valid data position */
	108	size_t size; /* size of data segment */
	109	unsigned char data[0]; /* data pointer */
718e3744	110	};
	111
	112	/* First in first out queue structure. */
d62a17ae	113	struct stream_fifo {
363e24c6 QY	114	/* lock for mt-safe operations */
	115	pthread_mutex_t mtx;
	116
	117	/* number of streams in this fifo */
	118	_Atomic size_t count;
03ed85a6 DS	119	#if defined DEV_BUILD
	120	_Atomic size_t max_count;
	121	#endif
718e3744	122
d62a17ae	123	struct stream *head;
d62a17ae	124	struct stream *tail;
718e3744	125	};
	126
	127	/* Utility macros. */
718e3744	128	#define STREAM_SIZE(S) ((S)->size)
d62a17ae	129	/* number of bytes which can still be written */
050c013a	130	#define STREAM_WRITEABLE(S) ((S)->size - (S)->endp)
d62a17ae	131	/* number of bytes still to be read */
050c013a	132	#define STREAM_READABLE(S) ((S)->endp - (S)->getp)
050c013a	133
d62a17ae	134	#define STREAM_CONCAT_REMAIN(S1, S2, size) ((size) - (S1)->endp - (S2)->endp)
8c71e481	135
2d34fb80 QY	136	/* this macro is deprecated, but not slated for removal anytime soon */
	137	#define STREAM_DATA(S) ((S)->data)
	138
d62a17ae	139	/* Stream prototypes.
4b201d46	140	* For stream_{put,get}S, the S suffix mean:
	141	*
	142	* c: character (unsigned byte)
	143	* w: word (two bytes)
	144	* l: long (two words)
	145	* q: quad (four words)
	146	*/
d62a17ae	147	extern struct stream *stream_new(size_t);
	148	extern void stream_free(struct stream *);
	149	extern struct stream stream_copy(struct stream , struct stream *src);
	150	extern struct stream stream_dup(struct stream );
43888669 DS	151
	152	#if CONFDATE > 20190821
	153	CPP_NOTICE("lib: time to remove stream_resize_orig")
	154	#endif
	155	extern size_t stream_resize_orig(struct stream *s, size_t newsize);
	156	#define stream_resize stream_resize_orig
	157	extern size_t stream_resize_inplace(struct stream **sptr, size_t newsize);
	158
d62a17ae	159	extern size_t stream_get_getp(struct stream *);
	160	extern size_t stream_get_endp(struct stream *);
	161	extern size_t stream_get_size(struct stream *);
d7c0a89a	162	extern uint8_t stream_get_data(struct stream );
8cc4198f	163
8c71e481 PM	164	/**
	165	* Create a new stream structure; copy offset bytes from s1 to the new
	166	* stream; copy s2 data to the new stream; copy rest of s1 data to the
	167	* new stream.
	168	*/
	169	extern struct stream stream_dupcat(struct stream s1, struct stream *s2,
	170	size_t offset);
	171
d62a17ae	172	extern void stream_set_getp(struct stream *, size_t);
	173	extern void stream_set_endp(struct stream *, size_t);
	174	extern void stream_forward_getp(struct stream *, size_t);
	175	extern void stream_forward_endp(struct stream *, size_t);
8cc4198f	176
8cc4198f	177	/* steam_put: NULL source zeroes out size_t bytes of stream */
d62a17ae	178	extern void stream_put(struct stream , const void , size_t);
d7c0a89a QY	179	extern int stream_putc(struct stream *, uint8_t);
	180	extern int stream_putc_at(struct stream *, size_t, uint8_t);
	181	extern int stream_putw(struct stream *, uint16_t);
	182	extern int stream_putw_at(struct stream *, size_t, uint16_t);
	183	extern int stream_put3(struct stream *, uint32_t);
	184	extern int stream_put3_at(struct stream *, size_t, uint32_t);
	185	extern int stream_putl(struct stream *, uint32_t);
	186	extern int stream_putl_at(struct stream *, size_t, uint32_t);
d62a17ae	187	extern int stream_putq(struct stream *, uint64_t);
d62a17ae	188	extern int stream_putq_at(struct stream *, size_t, uint64_t);
d7c0a89a	189	extern int stream_put_ipv4(struct stream *, uint32_t);
d62a17ae	190	extern int stream_put_in_addr(struct stream , struct in_addr );
	191	extern int stream_put_in_addr_at(struct stream , size_t, struct in_addr );
	192	extern int stream_put_in6_addr_at(struct stream , size_t, struct in6_addr );
	193	extern int stream_put_prefix_addpath(struct stream , struct prefix ,
	194	int addpath_encode,
d7c0a89a	195	uint32_t addpath_tx_id);
d62a17ae	196	extern int stream_put_prefix(struct stream , struct prefix );
	197	extern int stream_put_labeled_prefix(struct stream , struct prefix ,
	198	mpls_label_t *);
	199	extern void stream_get(void , struct stream , size_t);
051cc28c	200	extern bool stream_get2(void data, struct stream s, size_t size);
d62a17ae	201	extern void stream_get_from(void , struct stream , size_t, size_t);
d7c0a89a QY	202	extern uint8_t stream_getc(struct stream *);
	203	extern bool stream_getc2(struct stream s, uint8_t byte);
	204	extern uint8_t stream_getc_from(struct stream *, size_t);
	205	extern uint16_t stream_getw(struct stream *);
051cc28c	206	extern bool stream_getw2(struct stream s, uint16_t word);
d7c0a89a QY	207	extern uint16_t stream_getw_from(struct stream *, size_t);
	208	extern uint32_t stream_get3(struct stream *);
	209	extern uint32_t stream_get3_from(struct stream *, size_t);
	210	extern uint32_t stream_getl(struct stream *);
051cc28c	211	extern bool stream_getl2(struct stream s, uint32_t l);
d7c0a89a	212	extern uint32_t stream_getl_from(struct stream *, size_t);
d62a17ae	213	extern uint64_t stream_getq(struct stream *);
d62a17ae	214	extern uint64_t stream_getq_from(struct stream *, size_t);
d7c0a89a	215	extern uint32_t stream_get_ipv4(struct stream *);
718e3744	216
16f1b9ee	217	/* IEEE-754 floats */
d62a17ae	218	extern float stream_getf(struct stream *);
	219	extern double stream_getd(struct stream *);
	220	extern int stream_putf(struct stream *, float);
	221	extern int stream_putd(struct stream *, double);
16f1b9ee	222
718e3744	223	#undef stream_read
718e3744	224	#undef stream_write
262feb1a	225
d62a17ae	226	/* Deprecated: assumes blocking I/O. Will be removed.
262feb1a	227	Use stream_read_try instead. */
d62a17ae	228	extern int stream_read(struct stream *, int, size_t);
262feb1a	229
262feb1a	230	/* Read up to size bytes into the stream.
	231	Return code:
	232	>0: number of bytes read
	233	0: end-of-file
	234	-1: fatal error
	235	-2: transient error, should retry later (i.e. EAGAIN or EINTR)
	236	This is suitable for use with non-blocking file descriptors.
	237	*/
	238	extern ssize_t stream_read_try(struct stream *s, int fd, size_t size);
	239
d62a17ae	240	extern ssize_t stream_recvmsg(struct stream s, int fd, struct msghdr ,
	241	int flags, size_t size);
	242	extern ssize_t stream_recvfrom(struct stream *s, int fd, size_t len, int flags,
	243	struct sockaddr from, socklen_t fromlen);
	244	extern size_t stream_write(struct stream , const void , size_t);
718e3744	245
8cc4198f	246	/* reset the stream. See Note above */
d62a17ae	247	extern void stream_reset(struct stream *);
	248	extern int stream_flush(struct stream *, int);
	249	extern int stream_empty(struct stream ); / is the stream empty? */
050c013a	250
050c013a	251	/* deprecated */
d7c0a89a	252	extern uint8_t stream_pnt(struct stream );
718e3744	253
363e24c6 QY	254	/*
	255	* Operations on struct stream_fifo.
	256	*
	257	* Each function has a safe variant, which ensures that the operation performed
	258	* is atomic with respect to the operations performed by all other safe
	259	* variants. In other words, the safe variants lock the stream_fifo's mutex
	260	* before performing their action. These are provided for convenience when
	261	* using stream_fifo in a multithreaded context, to alleviate the need for the
	262	* caller to implement their own synchronization around the stream_fifo.
	263	*
	264	* The following functions do not have safe variants. The caller must ensure
	265	* that these operations are performed safely in a multithreaded context:
	266	* - stream_fifo_new
	267	* - stream_fifo_free
	268	*/
	269
	270	/*
	271	* Create a new stream_fifo.
	272	*
	273	* Returns:
	274	* newly created stream_fifo
	275	*/
d62a17ae	276	extern struct stream_fifo *stream_fifo_new(void);
363e24c6 QY	277
	278	/*
	279	* Push a stream onto a stream_fifo.
	280	*
	281	* fifo
	282	* the stream_fifo to push onto
	283	*
	284	* s
	285	* the stream to push onto the stream_fifo
	286	*/
d62a17ae	287	extern void stream_fifo_push(struct stream_fifo fifo, struct stream s);
363e24c6 QY	288	extern void stream_fifo_push_safe(struct stream_fifo fifo, struct stream s);
	289
	290	/*
	291	* Pop a stream off a stream_fifo.
	292	*
	293	* fifo
	294	* the stream_fifo to pop from
	295	*
	296	* Returns:
	297	* the next stream in the stream_fifo
	298	*/
d62a17ae	299	extern struct stream stream_fifo_pop(struct stream_fifo fifo);
363e24c6 QY	300	extern struct stream stream_fifo_pop_safe(struct stream_fifo fifo);
	301
	302	/*
	303	* Retrieve the next stream from a stream_fifo without popping it.
	304	*
	305	* fifo
	306	* the stream_fifo to operate on
	307	*
	308	* Returns:
	309	* the next stream that would be returned from stream_fifo_pop
	310	*/
d62a17ae	311	extern struct stream stream_fifo_head(struct stream_fifo fifo);
363e24c6 QY	312	extern struct stream stream_fifo_head_safe(struct stream_fifo fifo);
	313
	314	/*
	315	* Remove all streams from a stream_fifo.
	316	*
	317	* fifo
	318	* the stream_fifo to clean
	319	*/
d62a17ae	320	extern void stream_fifo_clean(struct stream_fifo *fifo);
363e24c6 QY	321	extern void stream_fifo_clean_safe(struct stream_fifo *fifo);
	322
	323	/*
	324	* Retrieve number of streams on a stream_fifo.
	325	*
	326	* fifo
	327	* the stream_fifo to retrieve the count for
	328	*
	329	* Returns:
	330	* the number of streams on the stream_fifo
	331	*/
	332	extern size_t stream_fifo_count_safe(struct stream_fifo *fifo);
	333
	334	/*
	335	* Free a stream_fifo.
	336	*
	337	* Calls stream_fifo_clean, then deinitializes the stream_fifo and frees it.
	338	*
	339	* fifo
	340	* the stream_fifo to free
	341	*/
d62a17ae	342	extern void stream_fifo_free(struct stream_fifo *fifo);
718e3744	343
937652c6 DL	344	/* This is here because "<< 24" is particularly problematic in C.
	345	* This is because the left operand of << is integer-promoted, which means
	346	* an uint8_t gets converted into a signed int. Shifting into the sign
	347	* bit of a signed int is theoretically undefined behaviour, so - the left
	348	* operand needs to be cast to unsigned.
	349	*
	350	* This is not a problem for 16- or 8-bit values (they don't reach the sign
	351	* bit), for 64-bit values (you need to cast them anyway), and neither for
	352	* encoding (because it's downcasted.)
	353	*/
	354	static inline uint8_t ptr_get_be32(uint8_t ptr, uint32_t *out)
	355	{
	356	uint32_t tmp;
	357	memcpy(&tmp, ptr, sizeof(tmp));
	358	*out = ntohl(tmp);
	359	return ptr + 4;
	360	}
	361
051cc28c DS	362	/*
	363	* so Normal stream_getX functions assert. Which is anathema
	364	* to keeping a daemon up and running when something goes south
	365	* Provide a stream_getX2 functions that do not assert.
	366	* In addition provide these macro's that upon failure
	367	* goto stream_failure. This is modeled upon some NL_XX
	368	* macros in the linux kernel.
	369	*
	370	* This change allows for proper memory freeing
	371	* after we've detected an error.
	372	*
	373	* In the future we will be removing the assert in
	374	* the stream functions but we need a transition
	375	* plan.
	376	*/
996c9314 LB	377	#define STREAM_GETC(S, P) \
	378	do { \
	379	uint8_t _pval; \
	380	if (!stream_getc2((S), &_pval)) \
	381	goto stream_failure; \
	382	(P) = _pval; \
051cc28c DS	383	} while (0)
051cc28c DS	384
996c9314 LB	385	#define STREAM_GETW(S, P) \
	386	do { \
	387	uint16_t _pval; \
	388	if (!stream_getw2((S), &_pval)) \
	389	goto stream_failure; \
	390	(P) = _pval; \
051cc28c DS	391	} while (0)
051cc28c DS	392
996c9314 LB	393	#define STREAM_GETL(S, P) \
	394	do { \
	395	uint32_t _pval; \
	396	if (!stream_getl2((S), &_pval)) \
	397	goto stream_failure; \
	398	(P) = _pval; \
051cc28c DS	399	} while (0)
051cc28c DS	400
996c9314 LB	401	#define STREAM_GET(P, STR, SIZE) \
	402	do { \
	403	if (!stream_get2((P), (STR), (SIZE))) \
	404	goto stream_failure; \
051cc28c DS	405	} while (0)
051cc28c DS	406
718e3744	407	#endif /* _ZEBRA_STREAM_H */