xref: /freebsd/sys/sys/sockbuf.h (revision 43283184)
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_TLS_RX	0x01		/* using KTLS on RX */
42 #define	SB_TLS_RX_RUNNING 0x02		/* KTLS RX operation running */
43 #define	SB_WAIT		0x04		/* someone is waiting for data/space */
44 #define	SB_SEL		0x08		/* someone is selecting */
45 #define	SB_ASYNC	0x10		/* ASYNC I/O, need signals */
46 #define	SB_UPCALL	0x20		/* someone wants an upcall */
47 #define	SB_NOINTR	0x40		/* operations not interruptible */
48 #define	SB_AIO		0x80		/* AIO operations queued */
49 #define	SB_KNOTE	0x100		/* kernel note attached */
50 #define	SB_NOCOALESCE	0x200		/* don't coalesce new data into existing mbufs */
51 #define	SB_IN_TOE	0x400		/* socket buffer is in the middle of an operation */
52 #define	SB_AUTOSIZE	0x800		/* automatically size socket buffer */
53 #define	SB_STOP		0x1000		/* backpressure indicator */
54 #define	SB_AIO_RUNNING	0x2000		/* AIO operation running */
55 #define	SB_TLS_IFNET	0x4000		/* has used / is using ifnet KTLS */
56 
57 #define	SBS_CANTSENDMORE	0x0010	/* can't send more data to peer */
58 #define	SBS_CANTRCVMORE		0x0020	/* can't receive more data from peer */
59 #define	SBS_RCVATMARK		0x0040	/* at mark on input */
60 
61 #if defined(_KERNEL) || defined(_WANT_SOCKET)
62 #include <sys/_lock.h>
63 #include <sys/_mutex.h>
64 #include <sys/_sx.h>
65 #include <sys/_task.h>
66 
67 #define	SB_MAX		(2*1024*1024)	/* default for max chars in sockbuf */
68 
69 struct ktls_session;
70 struct mbuf;
71 struct sockaddr;
72 struct socket;
73 struct thread;
74 struct selinfo;
75 
76 /*
77  * Variables for socket buffering.
78  *
79  * Locking key to struct sockbuf:
80  * (a) locked by SOCKBUF_LOCK().
81  */
82 struct sockbuf {
83 	struct	mtx *sb_mtx;		/* sockbuf lock */
84 	struct	selinfo *sb_sel;	/* process selecting read/write */
85 	short	sb_state;	/* (a) socket state on sockbuf */
86 	short	sb_flags;	/* (a) flags, see above */
87 	struct	mbuf *sb_mb;	/* (a) the mbuf chain */
88 	struct	mbuf *sb_mbtail; /* (a) the last mbuf in the chain */
89 	struct	mbuf *sb_lastrecord;	/* (a) first mbuf of last
90 					 * record in socket buffer */
91 	struct	mbuf *sb_sndptr; /* (a) pointer into mbuf chain */
92 	struct	mbuf *sb_fnrdy;	/* (a) pointer to first not ready buffer */
93 	u_int	sb_sndptroff;	/* (a) byte offset of ptr into chain */
94 	u_int	sb_acc;		/* (a) available chars in buffer */
95 	u_int	sb_ccc;		/* (a) claimed chars in buffer */
96 	u_int	sb_hiwat;	/* (a) max actual char count */
97 	u_int	sb_mbcnt;	/* (a) chars of mbufs used */
98 	u_int   sb_mcnt;        /* (a) number of mbufs in buffer */
99 	u_int   sb_ccnt;        /* (a) number of clusters in buffer */
100 	u_int	sb_mbmax;	/* (a) max chars of mbufs to use */
101 	u_int	sb_ctl;		/* (a) non-data chars in buffer */
102 	u_int	sb_tlscc;	/* (a) TLS chain characters */
103 	u_int	sb_tlsdcc;	/* (a) TLS characters being decrypted */
104 	int	sb_lowat;	/* (a) low water mark */
105 	sbintime_t	sb_timeo;	/* (a) timeout for read/write */
106 	struct	mbuf *sb_mtls;	/* (a) TLS mbuf chain */
107 	struct	mbuf *sb_mtlstail; /* (a) last mbuf in TLS chain */
108 	int	(*sb_upcall)(struct socket *, void *, int); /* (a) */
109 	void	*sb_upcallarg;	/* (a) */
110 	uint64_t sb_tls_seqno;	/* (a) TLS seqno */
111 	struct	ktls_session *sb_tls_info; /* (a + b) TLS state */
112 	TAILQ_HEAD(, kaiocb) sb_aiojobq; /* (a) pending AIO ops */
113 	struct	task sb_aiotask; /* AIO task */
114 };
115 
116 #endif	/* defined(_KERNEL) || defined(_WANT_SOCKET) */
117 #ifdef _KERNEL
118 
119 /* 'which' values for KPIs that operate on one buffer of a socket. */
120 typedef enum { SO_RCV, SO_SND } sb_which;
121 
122 /*
123  * Per-socket buffer mutex used to protect most fields in the socket buffer.
124  * These make use of the mutex pointer embedded in struct sockbuf, which
125  * currently just references mutexes in the containing socket.  The
126  * SOCK_SENDBUF_LOCK() etc. macros can be used instead of or in combination with
127  * these locking macros.
128  */
129 #define	SOCKBUF_MTX(_sb)		((_sb)->sb_mtx)
130 #define	SOCKBUF_LOCK(_sb)		mtx_lock(SOCKBUF_MTX(_sb))
131 #define	SOCKBUF_OWNED(_sb)		mtx_owned(SOCKBUF_MTX(_sb))
132 #define	SOCKBUF_UNLOCK(_sb)		mtx_unlock(SOCKBUF_MTX(_sb))
133 #define	SOCKBUF_LOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_OWNED)
134 #define	SOCKBUF_UNLOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_NOTOWNED)
135 
136 /*
137  * Socket buffer private mbuf(9) flags.
138  */
139 #define	M_NOTREADY	M_PROTO1	/* m_data not populated yet */
140 #define	M_BLOCKED	M_PROTO2	/* M_NOTREADY in front of m */
141 #define	M_NOTAVAIL	(M_NOTREADY | M_BLOCKED)
142 
143 void	sbappend(struct sockbuf *sb, struct mbuf *m, int flags);
144 void	sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags);
145 void	sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags);
146 void	sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags);
147 int	sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
148 	    struct mbuf *m0, struct mbuf *control);
149 int	sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
150 	    struct mbuf *m0, struct mbuf *control);
151 int	sbappendaddr_nospacecheck_locked(struct sockbuf *sb,
152 	    const struct sockaddr *asa, struct mbuf *m0, struct mbuf *control);
153 void	sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
154 	    struct mbuf *control, int flags);
155 void	sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
156 	    struct mbuf *control, int flags);
157 void	sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
158 void	sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0);
159 void	sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
160 struct mbuf *
161 	sbcreatecontrol(caddr_t p, int size, int type, int level);
162 struct mbuf *
163 	sbcreatecontrol_how(void *p, int size, int type, int level,
164 	    int wait);
165 void	sbdestroy(struct socket *, sb_which);
166 void	sbdrop(struct sockbuf *sb, int len);
167 void	sbdrop_locked(struct sockbuf *sb, int len);
168 struct mbuf *
169 	sbcut_locked(struct sockbuf *sb, int len);
170 void	sbdroprecord(struct sockbuf *sb);
171 void	sbdroprecord_locked(struct sockbuf *sb);
172 void	sbflush(struct sockbuf *sb);
173 void	sbflush_locked(struct sockbuf *sb);
174 void	sbrelease(struct socket *, sb_which);
175 void	sbrelease_locked(struct socket *, sb_which);
176 int	sbsetopt(struct socket *so, int cmd, u_long cc);
177 bool	sbreserve_locked(struct socket *so, sb_which which, u_long cc,
178 	    struct thread *td);
179 void	sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, u_int len);
180 struct mbuf *
181 	sbsndptr_noadv(struct sockbuf *sb, u_int off, u_int *moff);
182 struct mbuf *
183 	sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff);
184 int	sbwait(struct socket *, sb_which);
185 void	sballoc(struct sockbuf *, struct mbuf *);
186 void	sbfree(struct sockbuf *, struct mbuf *);
187 void	sballoc_ktls_rx(struct sockbuf *sb, struct mbuf *m);
188 void	sbfree_ktls_rx(struct sockbuf *sb, struct mbuf *m);
189 int	sbready(struct sockbuf *, struct mbuf *, int);
190 
191 /*
192  * Return how much data is available to be taken out of socket
193  * buffer right now.
194  */
195 static inline u_int
196 sbavail(struct sockbuf *sb)
197 {
198 
199 #if 0
200 	SOCKBUF_LOCK_ASSERT(sb);
201 #endif
202 	return (sb->sb_acc);
203 }
204 
205 /*
206  * Return how much data sits there in the socket buffer
207  * It might be that some data is not yet ready to be read.
208  */
209 static inline u_int
210 sbused(struct sockbuf *sb)
211 {
212 
213 #if 0
214 	SOCKBUF_LOCK_ASSERT(sb);
215 #endif
216 	return (sb->sb_ccc);
217 }
218 
219 /*
220  * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
221  * This is problematical if the fields are unsigned, as the space might
222  * still be negative (ccc > hiwat or mbcnt > mbmax).
223  */
224 static inline long
225 sbspace(struct sockbuf *sb)
226 {
227 	int bleft, mleft;		/* size should match sockbuf fields */
228 
229 #if 0
230 	SOCKBUF_LOCK_ASSERT(sb);
231 #endif
232 
233 	if (sb->sb_flags & SB_STOP)
234 		return(0);
235 
236 	bleft = sb->sb_hiwat - sb->sb_ccc;
237 	mleft = sb->sb_mbmax - sb->sb_mbcnt;
238 
239 	return ((bleft < mleft) ? bleft : mleft);
240 }
241 
242 #define SB_EMPTY_FIXUP(sb) do {						\
243 	if ((sb)->sb_mb == NULL) {					\
244 		(sb)->sb_mbtail = NULL;					\
245 		(sb)->sb_lastrecord = NULL;				\
246 	}								\
247 } while (/*CONSTCOND*/0)
248 
249 #ifdef SOCKBUF_DEBUG
250 void	sblastrecordchk(struct sockbuf *, const char *, int);
251 void	sblastmbufchk(struct sockbuf *, const char *, int);
252 void	sbcheck(struct sockbuf *, const char *, int);
253 #define	SBLASTRECORDCHK(sb)	sblastrecordchk((sb), __FILE__, __LINE__)
254 #define	SBLASTMBUFCHK(sb)	sblastmbufchk((sb), __FILE__, __LINE__)
255 #define	SBCHECK(sb)		sbcheck((sb), __FILE__, __LINE__)
256 #else
257 #define	SBLASTRECORDCHK(sb)	do {} while (0)
258 #define	SBLASTMBUFCHK(sb)	do {} while (0)
259 #define	SBCHECK(sb)		do {} while (0)
260 #endif /* SOCKBUF_DEBUG */
261 
262 #endif /* _KERNEL */
263 
264 #endif /* _SYS_SOCKBUF_H_ */
265