[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; /* 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)

/* deprecated macros - do not use in new code */
#if defined(VERSION_TYPE_DEV) && CONFDATE > 20181128
CPP_NOTICE("lib: time to remove deprecated stream.h macros")
#endif
#define STREAM_PNT(S)   stream_pnt((S))
#define STREAM_REMAIN(S) STREAM_WRITEABLE((S))

/* 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(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 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
	101	/* Remainder is *private* to stream
	102	* direct access is frowned upon!
	103	* Use the appropriate functions/macros
	104	*/
	105	size_t getp; /* next get position */
	106	size_t endp; /* last valid data position */
	107	size_t size; /* size of data segment */
	108	unsigned char data; / data pointer */
718e3744	109	};
	110
	111	/* First in first out queue structure. */
d62a17ae	112	struct stream_fifo {
363e24c6 QY	113	/* lock for mt-safe operations */
	114	pthread_mutex_t mtx;
	115
	116	/* number of streams in this fifo */
	117	_Atomic size_t count;
03ed85a6 DS	118	#if defined DEV_BUILD
	119	_Atomic size_t max_count;
	120	#endif
718e3744	121
d62a17ae	122	struct stream *head;
d62a17ae	123	struct stream *tail;
718e3744	124	};
	125
	126	/* Utility macros. */
718e3744	127	#define STREAM_SIZE(S) ((S)->size)
d62a17ae	128	/* number of bytes which can still be written */
050c013a	129	#define STREAM_WRITEABLE(S) ((S)->size - (S)->endp)
d62a17ae	130	/* number of bytes still to be read */
050c013a	131	#define STREAM_READABLE(S) ((S)->endp - (S)->getp)
050c013a	132
d62a17ae	133	#define STREAM_CONCAT_REMAIN(S1, S2, size) ((size) - (S1)->endp - (S2)->endp)
8c71e481	134
050c013a	135	/* deprecated macros - do not use in new code */
e24be241	136	#if defined(VERSION_TYPE_DEV) && CONFDATE > 20181128
2d34fb80 QY	137	CPP_NOTICE("lib: time to remove deprecated stream.h macros")
2d34fb80 QY	138	#endif
050c013a	139	#define STREAM_PNT(S) stream_pnt((S))
050c013a	140	#define STREAM_REMAIN(S) STREAM_WRITEABLE((S))
718e3744	141
2d34fb80 QY	142	/* this macro is deprecated, but not slated for removal anytime soon */
	143	#define STREAM_DATA(S) ((S)->data)
	144
d62a17ae	145	/* Stream prototypes.
4b201d46	146	* For stream_{put,get}S, the S suffix mean:
	147	*
	148	* c: character (unsigned byte)
	149	* w: word (two bytes)
	150	* l: long (two words)
	151	* q: quad (four words)
	152	*/
d62a17ae	153	extern struct stream *stream_new(size_t);
	154	extern void stream_free(struct stream *);
	155	extern struct stream stream_copy(struct stream , struct stream *src);
	156	extern struct stream stream_dup(struct stream );
	157	extern size_t stream_resize(struct stream *, size_t);
	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);
d62a17ae	189	extern int stream_put_in_addr(struct stream , struct in_addr );
	190	extern int stream_put_in_addr_at(struct stream , size_t, struct in_addr );
	191	extern int stream_put_in6_addr_at(struct stream , size_t, struct in6_addr );
	192	extern int stream_put_prefix_addpath(struct stream , struct prefix ,
	193	int addpath_encode,
d7c0a89a	194	uint32_t addpath_tx_id);
d62a17ae	195	extern int stream_put_prefix(struct stream , struct prefix );
	196	extern int stream_put_labeled_prefix(struct stream , struct prefix ,
	197	mpls_label_t *);
	198	extern void stream_get(void , struct stream , size_t);
051cc28c	199	extern bool stream_get2(void data, struct stream s, size_t size);
d62a17ae	200	extern void stream_get_from(void , struct stream , size_t, size_t);
d7c0a89a QY	201	extern uint8_t stream_getc(struct stream *);
	202	extern bool stream_getc2(struct stream s, uint8_t byte);
	203	extern uint8_t stream_getc_from(struct stream *, size_t);
	204	extern uint16_t stream_getw(struct stream *);
051cc28c	205	extern bool stream_getw2(struct stream s, uint16_t word);
d7c0a89a QY	206	extern uint16_t stream_getw_from(struct stream *, size_t);
	207	extern uint32_t stream_get3(struct stream *);
	208	extern uint32_t stream_get3_from(struct stream *, size_t);
	209	extern uint32_t stream_getl(struct stream *);
051cc28c	210	extern bool stream_getl2(struct stream s, uint32_t l);
d7c0a89a	211	extern uint32_t stream_getl_from(struct stream *, size_t);
d62a17ae	212	extern uint64_t stream_getq(struct stream *);
d62a17ae	213	extern uint64_t stream_getq_from(struct stream *, size_t);
d7c0a89a	214	extern uint32_t stream_get_ipv4(struct stream *);
718e3744	215
16f1b9ee	216	/* IEEE-754 floats */
d62a17ae	217	extern float stream_getf(struct stream *);
	218	extern double stream_getd(struct stream *);
	219	extern int stream_putf(struct stream *, float);
	220	extern int stream_putd(struct stream *, double);
16f1b9ee	221
718e3744	222	#undef stream_read
718e3744	223	#undef stream_write
262feb1a	224
d62a17ae	225	/* Deprecated: assumes blocking I/O. Will be removed.
262feb1a	226	Use stream_read_try instead. */
d62a17ae	227	extern int stream_read(struct stream *, int, size_t);
262feb1a	228
262feb1a	229	/* Read up to size bytes into the stream.
	230	Return code:
	231	>0: number of bytes read
	232	0: end-of-file
	233	-1: fatal error
	234	-2: transient error, should retry later (i.e. EAGAIN or EINTR)
	235	This is suitable for use with non-blocking file descriptors.
	236	*/
	237	extern ssize_t stream_read_try(struct stream *s, int fd, size_t size);
	238
d62a17ae	239	extern ssize_t stream_recvmsg(struct stream s, int fd, struct msghdr ,
	240	int flags, size_t size);
	241	extern ssize_t stream_recvfrom(struct stream *s, int fd, size_t len, int flags,
	242	struct sockaddr from, socklen_t fromlen);
	243	extern size_t stream_write(struct stream , const void , size_t);
718e3744	244
8cc4198f	245	/* reset the stream. See Note above */
d62a17ae	246	extern void stream_reset(struct stream *);
	247	extern int stream_flush(struct stream *, int);
	248	extern int stream_empty(struct stream ); / is the stream empty? */
050c013a	249
050c013a	250	/* deprecated */
d7c0a89a	251	extern uint8_t stream_pnt(struct stream );
718e3744	252
363e24c6 QY	253	/*
	254	* Operations on struct stream_fifo.
	255	*
	256	* Each function has a safe variant, which ensures that the operation performed
	257	* is atomic with respect to the operations performed by all other safe
	258	* variants. In other words, the safe variants lock the stream_fifo's mutex
	259	* before performing their action. These are provided for convenience when
	260	* using stream_fifo in a multithreaded context, to alleviate the need for the
	261	* caller to implement their own synchronization around the stream_fifo.
	262	*
	263	* The following functions do not have safe variants. The caller must ensure
	264	* that these operations are performed safely in a multithreaded context:
	265	* - stream_fifo_new
	266	* - stream_fifo_free
	267	*/
	268
	269	/*
	270	* Create a new stream_fifo.
	271	*
	272	* Returns:
	273	* newly created stream_fifo
	274	*/
d62a17ae	275	extern struct stream_fifo *stream_fifo_new(void);
363e24c6 QY	276
	277	/*
	278	* Push a stream onto a stream_fifo.
	279	*
	280	* fifo
	281	* the stream_fifo to push onto
	282	*
	283	* s
	284	* the stream to push onto the stream_fifo
	285	*/
d62a17ae	286	extern void stream_fifo_push(struct stream_fifo fifo, struct stream s);
363e24c6 QY	287	extern void stream_fifo_push_safe(struct stream_fifo fifo, struct stream s);
	288
	289	/*
	290	* Pop a stream off a stream_fifo.
	291	*
	292	* fifo
	293	* the stream_fifo to pop from
	294	*
	295	* Returns:
	296	* the next stream in the stream_fifo
	297	*/
d62a17ae	298	extern struct stream stream_fifo_pop(struct stream_fifo fifo);
363e24c6 QY	299	extern struct stream stream_fifo_pop_safe(struct stream_fifo fifo);
	300
	301	/*
	302	* Retrieve the next stream from a stream_fifo without popping it.
	303	*
	304	* fifo
	305	* the stream_fifo to operate on
	306	*
	307	* Returns:
	308	* the next stream that would be returned from stream_fifo_pop
	309	*/
d62a17ae	310	extern struct stream stream_fifo_head(struct stream_fifo fifo);
363e24c6 QY	311	extern struct stream stream_fifo_head_safe(struct stream_fifo fifo);
	312
	313	/*
	314	* Remove all streams from a stream_fifo.
	315	*
	316	* fifo
	317	* the stream_fifo to clean
	318	*/
d62a17ae	319	extern void stream_fifo_clean(struct stream_fifo *fifo);
363e24c6 QY	320	extern void stream_fifo_clean_safe(struct stream_fifo *fifo);
	321
	322	/*
	323	* Retrieve number of streams on a stream_fifo.
	324	*
	325	* fifo
	326	* the stream_fifo to retrieve the count for
	327	*
	328	* Returns:
	329	* the number of streams on the stream_fifo
	330	*/
	331	extern size_t stream_fifo_count_safe(struct stream_fifo *fifo);
	332
	333	/*
	334	* Free a stream_fifo.
	335	*
	336	* Calls stream_fifo_clean, then deinitializes the stream_fifo and frees it.
	337	*
	338	* fifo
	339	* the stream_fifo to free
	340	*/
d62a17ae	341	extern void stream_fifo_free(struct stream_fifo *fifo);
718e3744	342
937652c6 DL	343	/* This is here because "<< 24" is particularly problematic in C.
	344	* This is because the left operand of << is integer-promoted, which means
	345	* an uint8_t gets converted into a signed int. Shifting into the sign
	346	* bit of a signed int is theoretically undefined behaviour, so - the left
	347	* operand needs to be cast to unsigned.
	348	*
	349	* This is not a problem for 16- or 8-bit values (they don't reach the sign
	350	* bit), for 64-bit values (you need to cast them anyway), and neither for
	351	* encoding (because it's downcasted.)
	352	*/
	353	static inline uint8_t ptr_get_be32(uint8_t ptr, uint32_t *out)
	354	{
	355	uint32_t tmp;
	356	memcpy(&tmp, ptr, sizeof(tmp));
	357	*out = ntohl(tmp);
	358	return ptr + 4;
	359	}
	360
051cc28c DS	361	/*
	362	* so Normal stream_getX functions assert. Which is anathema
	363	* to keeping a daemon up and running when something goes south
	364	* Provide a stream_getX2 functions that do not assert.
	365	* In addition provide these macro's that upon failure
	366	* goto stream_failure. This is modeled upon some NL_XX
	367	* macros in the linux kernel.
	368	*
	369	* This change allows for proper memory freeing
	370	* after we've detected an error.
	371	*
	372	* In the future we will be removing the assert in
	373	* the stream functions but we need a transition
	374	* plan.
	375	*/
996c9314 LB	376	#define STREAM_GETC(S, P) \
	377	do { \
	378	uint8_t _pval; \
	379	if (!stream_getc2((S), &_pval)) \
	380	goto stream_failure; \
	381	(P) = _pval; \
051cc28c DS	382	} while (0)
051cc28c DS	383
996c9314 LB	384	#define STREAM_GETW(S, P) \
	385	do { \
	386	uint16_t _pval; \
	387	if (!stream_getw2((S), &_pval)) \
	388	goto stream_failure; \
	389	(P) = _pval; \
051cc28c DS	390	} while (0)
051cc28c DS	391
996c9314 LB	392	#define STREAM_GETL(S, P) \
	393	do { \
	394	uint32_t _pval; \
	395	if (!stream_getl2((S), &_pval)) \
	396	goto stream_failure; \
	397	(P) = _pval; \
051cc28c DS	398	} while (0)
051cc28c DS	399
996c9314 LB	400	#define STREAM_GET(P, STR, SIZE) \
	401	do { \
	402	if (!stream_get2((P), (STR), (SIZE))) \
	403	goto stream_failure; \
051cc28c DS	404	} while (0)
051cc28c DS	405
718e3744	406	#endif /* _ZEBRA_STREAM_H */