xref: /freebsd/sys/sys/sockbuf.h (revision b00ab754)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)socketvar.h	8.3 (Berkeley) 2/19/95
32  *
33  * $FreeBSD$
34  */
35 #ifndef _SYS_SOCKBUF_H_
36 #define _SYS_SOCKBUF_H_
37 
38 /*
39  * Constants for sb_flags field of struct sockbuf/xsockbuf.
40  */
41 #define	SB_WAIT		0x04		/* someone is waiting for data/space */
42 #define	SB_SEL		0x08		/* someone is selecting */
43 #define	SB_ASYNC	0x10		/* ASYNC I/O, need signals */
44 #define	SB_UPCALL	0x20		/* someone wants an upcall */
45 #define	SB_NOINTR	0x40		/* operations not interruptible */
46 #define	SB_AIO		0x80		/* AIO operations queued */
47 #define	SB_KNOTE	0x100		/* kernel note attached */
48 #define	SB_NOCOALESCE	0x200		/* don't coalesce new data into existing mbufs */
49 #define	SB_IN_TOE	0x400		/* socket buffer is in the middle of an operation */
50 #define	SB_AUTOSIZE	0x800		/* automatically size socket buffer */
51 #define	SB_STOP		0x1000		/* backpressure indicator */
52 #define	SB_AIO_RUNNING	0x2000		/* AIO operation running */
53 
54 #define	SBS_CANTSENDMORE	0x0010	/* can't send more data to peer */
55 #define	SBS_CANTRCVMORE		0x0020	/* can't receive more data from peer */
56 #define	SBS_RCVATMARK		0x0040	/* at mark on input */
57 
58 #if defined(_KERNEL) || defined(_WANT_SOCKET)
59 #include <sys/_lock.h>
60 #include <sys/_mutex.h>
61 #include <sys/_sx.h>
62 #include <sys/_task.h>
63 
64 #define	SB_MAX		(2*1024*1024)	/* default for max chars in sockbuf */
65 
66 struct mbuf;
67 struct sockaddr;
68 struct socket;
69 struct thread;
70 struct selinfo;
71 
72 /*
73  * Variables for socket buffering.
74  *
75  * Locking key to struct sockbuf:
76  * (a) locked by SOCKBUF_LOCK().
77  */
78 struct	sockbuf {
79 	struct	mtx sb_mtx;		/* sockbuf lock */
80 	struct	sx sb_sx;		/* prevent I/O interlacing */
81 	struct	selinfo *sb_sel;	/* process selecting read/write */
82 	short	sb_state;	/* (a) socket state on sockbuf */
83 #define	sb_startzero	sb_mb
84 	struct	mbuf *sb_mb;	/* (a) the mbuf chain */
85 	struct	mbuf *sb_mbtail; /* (a) the last mbuf in the chain */
86 	struct	mbuf *sb_lastrecord;	/* (a) first mbuf of last
87 					 * record in socket buffer */
88 	struct	mbuf *sb_sndptr; /* (a) pointer into mbuf chain */
89 	struct	mbuf *sb_fnrdy;	/* (a) pointer to first not ready buffer */
90 	u_int	sb_sndptroff;	/* (a) byte offset of ptr into chain */
91 	u_int	sb_acc;		/* (a) available chars in buffer */
92 	u_int	sb_ccc;		/* (a) claimed chars in buffer */
93 	u_int	sb_hiwat;	/* (a) max actual char count */
94 	u_int	sb_mbcnt;	/* (a) chars of mbufs used */
95 	u_int   sb_mcnt;        /* (a) number of mbufs in buffer */
96 	u_int   sb_ccnt;        /* (a) number of clusters in buffer */
97 	u_int	sb_mbmax;	/* (a) max chars of mbufs to use */
98 	u_int	sb_ctl;		/* (a) non-data chars in buffer */
99 	int	sb_lowat;	/* (a) low water mark */
100 	sbintime_t	sb_timeo;	/* (a) timeout for read/write */
101 	short	sb_flags;	/* (a) flags, see below */
102 	int	(*sb_upcall)(struct socket *, void *, int); /* (a) */
103 	void	*sb_upcallarg;	/* (a) */
104 	TAILQ_HEAD(, kaiocb) sb_aiojobq; /* (a) pending AIO ops */
105 	struct	task sb_aiotask; /* AIO task */
106 };
107 
108 #endif	/* defined(_KERNEL) || defined(_WANT_SOCKET) */
109 #ifdef _KERNEL
110 
111 /*
112  * Per-socket buffer mutex used to protect most fields in the socket
113  * buffer.
114  */
115 #define	SOCKBUF_MTX(_sb)		(&(_sb)->sb_mtx)
116 #define	SOCKBUF_LOCK_INIT(_sb, _name) \
117 	mtx_init(SOCKBUF_MTX(_sb), _name, NULL, MTX_DEF)
118 #define	SOCKBUF_LOCK_DESTROY(_sb)	mtx_destroy(SOCKBUF_MTX(_sb))
119 #define	SOCKBUF_LOCK(_sb)		mtx_lock(SOCKBUF_MTX(_sb))
120 #define	SOCKBUF_OWNED(_sb)		mtx_owned(SOCKBUF_MTX(_sb))
121 #define	SOCKBUF_UNLOCK(_sb)		mtx_unlock(SOCKBUF_MTX(_sb))
122 #define	SOCKBUF_LOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_OWNED)
123 #define	SOCKBUF_UNLOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_NOTOWNED)
124 
125 /*
126  * Socket buffer private mbuf(9) flags.
127  */
128 #define	M_NOTREADY	M_PROTO1	/* m_data not populated yet */
129 #define	M_BLOCKED	M_PROTO2	/* M_NOTREADY in front of m */
130 #define	M_NOTAVAIL	(M_NOTREADY | M_BLOCKED)
131 
132 void	sbappend(struct sockbuf *sb, struct mbuf *m, int flags);
133 void	sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags);
134 void	sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags);
135 void	sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags);
136 int	sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
137 	    struct mbuf *m0, struct mbuf *control);
138 int	sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
139 	    struct mbuf *m0, struct mbuf *control);
140 int	sbappendaddr_nospacecheck_locked(struct sockbuf *sb,
141 	    const struct sockaddr *asa, struct mbuf *m0, struct mbuf *control);
142 int	sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
143 	    struct mbuf *control);
144 int	sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
145 	    struct mbuf *control);
146 void	sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
147 void	sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0);
148 void	sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
149 struct mbuf *
150 	sbcreatecontrol(caddr_t p, int size, int type, int level);
151 void	sbdestroy(struct sockbuf *sb, struct socket *so);
152 void	sbdrop(struct sockbuf *sb, int len);
153 void	sbdrop_locked(struct sockbuf *sb, int len);
154 struct mbuf *
155 	sbcut_locked(struct sockbuf *sb, int len);
156 void	sbdroprecord(struct sockbuf *sb);
157 void	sbdroprecord_locked(struct sockbuf *sb);
158 void	sbflush(struct sockbuf *sb);
159 void	sbflush_locked(struct sockbuf *sb);
160 void	sbrelease(struct sockbuf *sb, struct socket *so);
161 void	sbrelease_internal(struct sockbuf *sb, struct socket *so);
162 void	sbrelease_locked(struct sockbuf *sb, struct socket *so);
163 int	sbsetopt(struct socket *so, int cmd, u_long cc);
164 int	sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so,
165 	    struct thread *td);
166 struct mbuf *
167 	sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff);
168 struct mbuf *
169 	sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff);
170 int	sbwait(struct sockbuf *sb);
171 int	sblock(struct sockbuf *sb, int flags);
172 void	sbunlock(struct sockbuf *sb);
173 void	sballoc(struct sockbuf *, struct mbuf *);
174 void	sbfree(struct sockbuf *, struct mbuf *);
175 int	sbready(struct sockbuf *, struct mbuf *, int);
176 
177 /*
178  * Return how much data is available to be taken out of socket
179  * buffer right now.
180  */
181 static inline u_int
182 sbavail(struct sockbuf *sb)
183 {
184 
185 #if 0
186 	SOCKBUF_LOCK_ASSERT(sb);
187 #endif
188 	return (sb->sb_acc);
189 }
190 
191 /*
192  * Return how much data sits there in the socket buffer
193  * It might be that some data is not yet ready to be read.
194  */
195 static inline u_int
196 sbused(struct sockbuf *sb)
197 {
198 
199 #if 0
200 	SOCKBUF_LOCK_ASSERT(sb);
201 #endif
202 	return (sb->sb_ccc);
203 }
204 
205 /*
206  * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
207  * This is problematical if the fields are unsigned, as the space might
208  * still be negative (ccc > hiwat or mbcnt > mbmax).
209  */
210 static inline long
211 sbspace(struct sockbuf *sb)
212 {
213 	int bleft, mleft;		/* size should match sockbuf fields */
214 
215 #if 0
216 	SOCKBUF_LOCK_ASSERT(sb);
217 #endif
218 
219 	if (sb->sb_flags & SB_STOP)
220 		return(0);
221 
222 	bleft = sb->sb_hiwat - sb->sb_ccc;
223 	mleft = sb->sb_mbmax - sb->sb_mbcnt;
224 
225 	return ((bleft < mleft) ? bleft : mleft);
226 }
227 
228 #define SB_EMPTY_FIXUP(sb) do {						\
229 	if ((sb)->sb_mb == NULL) {					\
230 		(sb)->sb_mbtail = NULL;					\
231 		(sb)->sb_lastrecord = NULL;				\
232 	}								\
233 } while (/*CONSTCOND*/0)
234 
235 #ifdef SOCKBUF_DEBUG
236 void	sblastrecordchk(struct sockbuf *, const char *, int);
237 void	sblastmbufchk(struct sockbuf *, const char *, int);
238 void	sbcheck(struct sockbuf *, const char *, int);
239 #define	SBLASTRECORDCHK(sb)	sblastrecordchk((sb), __FILE__, __LINE__)
240 #define	SBLASTMBUFCHK(sb)	sblastmbufchk((sb), __FILE__, __LINE__)
241 #define	SBCHECK(sb)		sbcheck((sb), __FILE__, __LINE__)
242 #else
243 #define	SBLASTRECORDCHK(sb)	do {} while (0)
244 #define	SBLASTMBUFCHK(sb)	do {} while (0)
245 #define	SBCHECK(sb)		do {} while (0)
246 #endif /* SOCKBUF_DEBUG */
247 
248 #endif /* _KERNEL */
249 
250 #endif /* _SYS_SOCKBUF_H_ */
251