xref: /freebsd/sys/sys/sockbuf.h (revision 1f1e2261)
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 #define	SB_TLS_RX_RESYNC 0x8000		/* KTLS RX lost HW sync */
57 
58 #define	SBS_CANTSENDMORE	0x0010	/* can't send more data to peer */
59 #define	SBS_CANTRCVMORE		0x0020	/* can't receive more data from peer */
60 #define	SBS_RCVATMARK		0x0040	/* at mark on input */
61 
62 #if defined(_KERNEL) || defined(_WANT_SOCKET)
63 #include <sys/_lock.h>
64 #include <sys/_mutex.h>
65 #include <sys/_sx.h>
66 #include <sys/_task.h>
67 
68 #define	SB_MAX		(2*1024*1024)	/* default for max chars in sockbuf */
69 
70 struct ktls_session;
71 struct mbuf;
72 struct sockaddr;
73 struct socket;
74 struct thread;
75 struct selinfo;
76 
77 /*
78  * Variables for socket buffering.
79  *
80  * Locking key to struct sockbuf:
81  * (a) locked by SOCKBUF_LOCK().
82  */
83 struct sockbuf {
84 	struct	mtx *sb_mtx;		/* sockbuf lock */
85 	struct	selinfo *sb_sel;	/* process selecting read/write */
86 	short	sb_state;	/* (a) socket state on sockbuf */
87 	short	sb_flags;	/* (a) flags, see above */
88 	struct	mbuf *sb_mb;	/* (a) the mbuf chain */
89 	struct	mbuf *sb_mbtail; /* (a) the last mbuf in the chain */
90 	struct	mbuf *sb_lastrecord;	/* (a) first mbuf of last
91 					 * record in socket buffer */
92 	struct	mbuf *sb_sndptr; /* (a) pointer into mbuf chain */
93 	struct	mbuf *sb_fnrdy;	/* (a) pointer to first not ready buffer */
94 	u_int	sb_sndptroff;	/* (a) byte offset of ptr into chain */
95 	u_int	sb_acc;		/* (a) available chars in buffer */
96 	u_int	sb_ccc;		/* (a) claimed chars in buffer */
97 	u_int	sb_hiwat;	/* (a) max actual char count */
98 	u_int	sb_mbcnt;	/* (a) chars of mbufs used */
99 	u_int	sb_mbmax;	/* (a) max chars of mbufs to use */
100 	u_int	sb_ctl;		/* (a) non-data chars in buffer */
101 	u_int	sb_tlscc;	/* (a) TLS chain characters */
102 	u_int	sb_tlsdcc;	/* (a) TLS characters being decrypted */
103 	int	sb_lowat;	/* (a) low water mark */
104 	sbintime_t	sb_timeo;	/* (a) timeout for read/write */
105 	struct	mbuf *sb_mtls;	/* (a) TLS mbuf chain */
106 	struct	mbuf *sb_mtlstail; /* (a) last mbuf in TLS chain */
107 	int	(*sb_upcall)(struct socket *, void *, int); /* (a) */
108 	void	*sb_upcallarg;	/* (a) */
109 	uint64_t sb_tls_seqno;	/* (a) TLS seqno */
110 	struct	ktls_session *sb_tls_info; /* (a + b) TLS state */
111 	TAILQ_HEAD(, kaiocb) sb_aiojobq; /* (a) pending AIO ops */
112 	struct	task sb_aiotask; /* AIO task */
113 };
114 
115 #endif	/* defined(_KERNEL) || defined(_WANT_SOCKET) */
116 #ifdef _KERNEL
117 
118 /* 'which' values for KPIs that operate on one buffer of a socket. */
119 typedef enum { SO_RCV, SO_SND } sb_which;
120 
121 /*
122  * Per-socket buffer mutex used to protect most fields in the socket buffer.
123  * These make use of the mutex pointer embedded in struct sockbuf, which
124  * currently just references mutexes in the containing socket.  The
125  * SOCK_SENDBUF_LOCK() etc. macros can be used instead of or in combination with
126  * these locking macros.
127  */
128 #define	SOCKBUF_MTX(_sb)		((_sb)->sb_mtx)
129 #define	SOCKBUF_LOCK(_sb)		mtx_lock(SOCKBUF_MTX(_sb))
130 #define	SOCKBUF_OWNED(_sb)		mtx_owned(SOCKBUF_MTX(_sb))
131 #define	SOCKBUF_UNLOCK(_sb)		mtx_unlock(SOCKBUF_MTX(_sb))
132 #define	SOCKBUF_LOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_OWNED)
133 #define	SOCKBUF_UNLOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_NOTOWNED)
134 
135 /*
136  * Socket buffer private mbuf(9) flags.
137  */
138 #define	M_NOTREADY	M_PROTO1	/* m_data not populated yet */
139 #define	M_BLOCKED	M_PROTO2	/* M_NOTREADY in front of m */
140 #define	M_NOTAVAIL	(M_NOTREADY | M_BLOCKED)
141 
142 void	sbappend(struct sockbuf *sb, struct mbuf *m, int flags);
143 void	sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags);
144 void	sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags);
145 void	sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags);
146 int	sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
147 	    struct mbuf *m0, struct mbuf *control);
148 int	sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
149 	    struct mbuf *m0, struct mbuf *control);
150 int	sbappendaddr_nospacecheck_locked(struct sockbuf *sb,
151 	    const struct sockaddr *asa, struct mbuf *m0, struct mbuf *control);
152 void	sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
153 	    struct mbuf *control, int flags);
154 void	sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
155 	    struct mbuf *control, int flags);
156 void	sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
157 void	sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0);
158 void	sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
159 struct mbuf *
160 	sbcreatecontrol(const void *p, u_int size, int type, int level,
161 	    int wait);
162 void	sbdestroy(struct socket *, sb_which);
163 void	sbdrop(struct sockbuf *sb, int len);
164 void	sbdrop_locked(struct sockbuf *sb, int len);
165 struct mbuf *
166 	sbcut_locked(struct sockbuf *sb, int len);
167 void	sbdroprecord(struct sockbuf *sb);
168 void	sbdroprecord_locked(struct sockbuf *sb);
169 void	sbflush(struct sockbuf *sb);
170 void	sbflush_locked(struct sockbuf *sb);
171 void	sbrelease(struct socket *, sb_which);
172 void	sbrelease_locked(struct socket *, sb_which);
173 int	sbsetopt(struct socket *so, int cmd, u_long cc);
174 bool	sbreserve_locked(struct socket *so, sb_which which, u_long cc,
175 	    struct thread *td);
176 void	sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, u_int len);
177 struct mbuf *
178 	sbsndptr_noadv(struct sockbuf *sb, u_int off, u_int *moff);
179 struct mbuf *
180 	sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff);
181 int	sbwait(struct socket *, sb_which);
182 void	sballoc(struct sockbuf *, struct mbuf *);
183 void	sbfree(struct sockbuf *, struct mbuf *);
184 void	sballoc_ktls_rx(struct sockbuf *sb, struct mbuf *m);
185 void	sbfree_ktls_rx(struct sockbuf *sb, struct mbuf *m);
186 int	sbready(struct sockbuf *, struct mbuf *, int);
187 
188 /*
189  * Return how much data is available to be taken out of socket
190  * buffer right now.
191  */
192 static inline u_int
193 sbavail(struct sockbuf *sb)
194 {
195 
196 #if 0
197 	SOCKBUF_LOCK_ASSERT(sb);
198 #endif
199 	return (sb->sb_acc);
200 }
201 
202 /*
203  * Return how much data sits there in the socket buffer
204  * It might be that some data is not yet ready to be read.
205  */
206 static inline u_int
207 sbused(struct sockbuf *sb)
208 {
209 
210 #if 0
211 	SOCKBUF_LOCK_ASSERT(sb);
212 #endif
213 	return (sb->sb_ccc);
214 }
215 
216 /*
217  * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
218  * This is problematical if the fields are unsigned, as the space might
219  * still be negative (ccc > hiwat or mbcnt > mbmax).
220  */
221 static inline long
222 sbspace(struct sockbuf *sb)
223 {
224 	int bleft, mleft;		/* size should match sockbuf fields */
225 
226 #if 0
227 	SOCKBUF_LOCK_ASSERT(sb);
228 #endif
229 
230 	if (sb->sb_flags & SB_STOP)
231 		return(0);
232 
233 	bleft = sb->sb_hiwat - sb->sb_ccc;
234 	mleft = sb->sb_mbmax - sb->sb_mbcnt;
235 
236 	return ((bleft < mleft) ? bleft : mleft);
237 }
238 
239 #define SB_EMPTY_FIXUP(sb) do {						\
240 	if ((sb)->sb_mb == NULL) {					\
241 		(sb)->sb_mbtail = NULL;					\
242 		(sb)->sb_lastrecord = NULL;				\
243 	}								\
244 } while (/*CONSTCOND*/0)
245 
246 #ifdef SOCKBUF_DEBUG
247 void	sblastrecordchk(struct sockbuf *, const char *, int);
248 void	sblastmbufchk(struct sockbuf *, const char *, int);
249 void	sbcheck(struct sockbuf *, const char *, int);
250 #define	SBLASTRECORDCHK(sb)	sblastrecordchk((sb), __FILE__, __LINE__)
251 #define	SBLASTMBUFCHK(sb)	sblastmbufchk((sb), __FILE__, __LINE__)
252 #define	SBCHECK(sb)		sbcheck((sb), __FILE__, __LINE__)
253 #else
254 #define	SBLASTRECORDCHK(sb)	do {} while (0)
255 #define	SBLASTMBUFCHK(sb)	do {} while (0)
256 #define	SBCHECK(sb)		do {} while (0)
257 #endif /* SOCKBUF_DEBUG */
258 
259 #endif /* _KERNEL */
260 
261 #endif /* _SYS_SOCKBUF_H_ */
262