xref: /freebsd/sys/sys/sockbuf.h (revision 076ad2f8)
1 /*-
2  * Copyright (c) 1982, 1986, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)socketvar.h	8.3 (Berkeley) 2/19/95
30  *
31  * $FreeBSD$
32  */
33 #ifndef _SYS_SOCKBUF_H_
34 #define _SYS_SOCKBUF_H_
35 #include <sys/selinfo.h>		/* for struct selinfo */
36 #include <sys/_lock.h>
37 #include <sys/_mutex.h>
38 #include <sys/_sx.h>
39 #include <sys/_task.h>
40 
41 #define	SB_MAX		(2*1024*1024)	/* default for max chars in sockbuf */
42 
43 /*
44  * Constants for sb_flags field of struct sockbuf.
45  */
46 #define	SB_WAIT		0x04		/* someone is waiting for data/space */
47 #define	SB_SEL		0x08		/* someone is selecting */
48 #define	SB_ASYNC	0x10		/* ASYNC I/O, need signals */
49 #define	SB_UPCALL	0x20		/* someone wants an upcall */
50 #define	SB_NOINTR	0x40		/* operations not interruptible */
51 #define	SB_AIO		0x80		/* AIO operations queued */
52 #define	SB_KNOTE	0x100		/* kernel note attached */
53 #define	SB_NOCOALESCE	0x200		/* don't coalesce new data into existing mbufs */
54 #define	SB_IN_TOE	0x400		/* socket buffer is in the middle of an operation */
55 #define	SB_AUTOSIZE	0x800		/* automatically size socket buffer */
56 #define	SB_STOP		0x1000		/* backpressure indicator */
57 #define	SB_AIO_RUNNING	0x2000		/* AIO operation running */
58 
59 #define	SBS_CANTSENDMORE	0x0010	/* can't send more data to peer */
60 #define	SBS_CANTRCVMORE		0x0020	/* can't receive more data from peer */
61 #define	SBS_RCVATMARK		0x0040	/* at mark on input */
62 
63 struct mbuf;
64 struct sockaddr;
65 struct socket;
66 struct thread;
67 
68 struct	xsockbuf {
69 	u_int	sb_cc;
70 	u_int	sb_hiwat;
71 	u_int	sb_mbcnt;
72 	u_int   sb_mcnt;
73 	u_int   sb_ccnt;
74 	u_int	sb_mbmax;
75 	int	sb_lowat;
76 	int	sb_timeo;
77 	short	sb_flags;
78 };
79 
80 /*
81  * Variables for socket buffering.
82  *
83  * Locking key to struct sockbuf:
84  * (a) locked by SOCKBUF_LOCK().
85  */
86 struct	sockbuf {
87 	struct	selinfo sb_sel;	/* process selecting read/write */
88 	struct	mtx sb_mtx;	/* sockbuf lock */
89 	struct	sx sb_sx;	/* prevent I/O interlacing */
90 	short	sb_state;	/* (a) socket state on sockbuf */
91 #define	sb_startzero	sb_mb
92 	struct	mbuf *sb_mb;	/* (a) the mbuf chain */
93 	struct	mbuf *sb_mbtail; /* (a) the last mbuf in the chain */
94 	struct	mbuf *sb_lastrecord;	/* (a) first mbuf of last
95 					 * record in socket buffer */
96 	struct	mbuf *sb_sndptr; /* (a) pointer into mbuf chain */
97 	struct	mbuf *sb_fnrdy;	/* (a) pointer to first not ready buffer */
98 	u_int	sb_sndptroff;	/* (a) byte offset of ptr into chain */
99 	u_int	sb_acc;		/* (a) available chars in buffer */
100 	u_int	sb_ccc;		/* (a) claimed chars in buffer */
101 	u_int	sb_hiwat;	/* (a) max actual char count */
102 	u_int	sb_mbcnt;	/* (a) chars of mbufs used */
103 	u_int   sb_mcnt;        /* (a) number of mbufs in buffer */
104 	u_int   sb_ccnt;        /* (a) number of clusters in buffer */
105 	u_int	sb_mbmax;	/* (a) max chars of mbufs to use */
106 	u_int	sb_ctl;		/* (a) non-data chars in buffer */
107 	int	sb_lowat;	/* (a) low water mark */
108 	sbintime_t	sb_timeo;	/* (a) timeout for read/write */
109 	short	sb_flags;	/* (a) flags, see below */
110 	int	(*sb_upcall)(struct socket *, void *, int); /* (a) */
111 	void	*sb_upcallarg;	/* (a) */
112 	TAILQ_HEAD(, kaiocb) sb_aiojobq; /* (a) pending AIO ops */
113 	struct	task sb_aiotask; /* AIO task */
114 };
115 
116 #ifdef _KERNEL
117 
118 /*
119  * Per-socket buffer mutex used to protect most fields in the socket
120  * buffer.
121  */
122 #define	SOCKBUF_MTX(_sb)		(&(_sb)->sb_mtx)
123 #define	SOCKBUF_LOCK_INIT(_sb, _name) \
124 	mtx_init(SOCKBUF_MTX(_sb), _name, NULL, MTX_DEF)
125 #define	SOCKBUF_LOCK_DESTROY(_sb)	mtx_destroy(SOCKBUF_MTX(_sb))
126 #define	SOCKBUF_LOCK(_sb)		mtx_lock(SOCKBUF_MTX(_sb))
127 #define	SOCKBUF_OWNED(_sb)		mtx_owned(SOCKBUF_MTX(_sb))
128 #define	SOCKBUF_UNLOCK(_sb)		mtx_unlock(SOCKBUF_MTX(_sb))
129 #define	SOCKBUF_LOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_OWNED)
130 #define	SOCKBUF_UNLOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_NOTOWNED)
131 
132 /*
133  * Socket buffer private mbuf(9) flags.
134  */
135 #define	M_NOTREADY	M_PROTO1	/* m_data not populated yet */
136 #define	M_BLOCKED	M_PROTO2	/* M_NOTREADY in front of m */
137 #define	M_NOTAVAIL	(M_NOTREADY | M_BLOCKED)
138 
139 void	sbappend(struct sockbuf *sb, struct mbuf *m, int flags);
140 void	sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags);
141 void	sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags);
142 void	sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags);
143 int	sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
144 	    struct mbuf *m0, struct mbuf *control);
145 int	sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
146 	    struct mbuf *m0, struct mbuf *control);
147 int	sbappendaddr_nospacecheck_locked(struct sockbuf *sb,
148 	    const struct sockaddr *asa, struct mbuf *m0, struct mbuf *control);
149 int	sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
150 	    struct mbuf *control);
151 int	sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
152 	    struct mbuf *control);
153 void	sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
154 void	sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0);
155 void	sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
156 struct mbuf *
157 	sbcreatecontrol(caddr_t p, int size, int type, int level);
158 void	sbdestroy(struct sockbuf *sb, struct socket *so);
159 void	sbdrop(struct sockbuf *sb, int len);
160 void	sbdrop_locked(struct sockbuf *sb, int len);
161 struct mbuf *
162 	sbcut_locked(struct sockbuf *sb, int len);
163 void	sbdroprecord(struct sockbuf *sb);
164 void	sbdroprecord_locked(struct sockbuf *sb);
165 void	sbflush(struct sockbuf *sb);
166 void	sbflush_locked(struct sockbuf *sb);
167 void	sbrelease(struct sockbuf *sb, struct socket *so);
168 void	sbrelease_internal(struct sockbuf *sb, struct socket *so);
169 void	sbrelease_locked(struct sockbuf *sb, struct socket *so);
170 int	sbreserve(struct sockbuf *sb, u_long cc, struct socket *so,
171 	    struct thread *td);
172 int	sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so,
173 	    struct thread *td);
174 struct mbuf *
175 	sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff);
176 struct mbuf *
177 	sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff);
178 void	sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb);
179 int	sbwait(struct sockbuf *sb);
180 int	sblock(struct sockbuf *sb, int flags);
181 void	sbunlock(struct sockbuf *sb);
182 void	sballoc(struct sockbuf *, struct mbuf *);
183 void	sbfree(struct sockbuf *, struct mbuf *);
184 int	sbready(struct sockbuf *, struct mbuf *, int);
185 
186 /*
187  * Return how much data is available to be taken out of socket
188  * buffer right now.
189  */
190 static inline u_int
191 sbavail(struct sockbuf *sb)
192 {
193 
194 #if 0
195 	SOCKBUF_LOCK_ASSERT(sb);
196 #endif
197 	return (sb->sb_acc);
198 }
199 
200 /*
201  * Return how much data sits there in the socket buffer
202  * It might be that some data is not yet ready to be read.
203  */
204 static inline u_int
205 sbused(struct sockbuf *sb)
206 {
207 
208 #if 0
209 	SOCKBUF_LOCK_ASSERT(sb);
210 #endif
211 	return (sb->sb_ccc);
212 }
213 
214 /*
215  * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
216  * This is problematical if the fields are unsigned, as the space might
217  * still be negative (ccc > hiwat or mbcnt > mbmax).
218  */
219 static inline long
220 sbspace(struct sockbuf *sb)
221 {
222 	int bleft, mleft;		/* size should match sockbuf fields */
223 
224 #if 0
225 	SOCKBUF_LOCK_ASSERT(sb);
226 #endif
227 
228 	if (sb->sb_flags & SB_STOP)
229 		return(0);
230 
231 	bleft = sb->sb_hiwat - sb->sb_ccc;
232 	mleft = sb->sb_mbmax - sb->sb_mbcnt;
233 
234 	return ((bleft < mleft) ? bleft : mleft);
235 }
236 
237 #define SB_EMPTY_FIXUP(sb) do {						\
238 	if ((sb)->sb_mb == NULL) {					\
239 		(sb)->sb_mbtail = NULL;					\
240 		(sb)->sb_lastrecord = NULL;				\
241 	}								\
242 } while (/*CONSTCOND*/0)
243 
244 #ifdef SOCKBUF_DEBUG
245 void	sblastrecordchk(struct sockbuf *, const char *, int);
246 void	sblastmbufchk(struct sockbuf *, const char *, int);
247 void	sbcheck(struct sockbuf *, const char *, int);
248 #define	SBLASTRECORDCHK(sb)	sblastrecordchk((sb), __FILE__, __LINE__)
249 #define	SBLASTMBUFCHK(sb)	sblastmbufchk((sb), __FILE__, __LINE__)
250 #define	SBCHECK(sb)		sbcheck((sb), __FILE__, __LINE__)
251 #else
252 #define	SBLASTRECORDCHK(sb)	do {} while (0)
253 #define	SBLASTMBUFCHK(sb)	do {} while (0)
254 #define	SBCHECK(sb)		do {} while (0)
255 #endif /* SOCKBUF_DEBUG */
256 
257 #endif /* _KERNEL */
258 
259 #endif /* _SYS_SOCKBUF_H_ */
260