xref: /freebsd/sys/sys/socketvar.h (revision f05cddf9)
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  * 4. 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 
34 #ifndef _SYS_SOCKETVAR_H_
35 #define _SYS_SOCKETVAR_H_
36 
37 #include <sys/queue.h>			/* for TAILQ macros */
38 #include <sys/selinfo.h>		/* for struct selinfo */
39 #include <sys/_lock.h>
40 #include <sys/_mutex.h>
41 #include <sys/_sx.h>
42 #include <sys/sockbuf.h>
43 #include <sys/sockstate.h>
44 #ifdef _KERNEL
45 #include <sys/sockopt.h>
46 #endif
47 
48 struct vnet;
49 
50 /*
51  * Kernel structure per socket.
52  * Contains send and receive buffer queues,
53  * handle on protocol and pointer to protocol
54  * private data and error information.
55  */
56 typedef	u_quad_t so_gen_t;
57 
58 struct socket;
59 
60 /*-
61  * Locking key to struct socket:
62  * (a) constant after allocation, no locking required.
63  * (b) locked by SOCK_LOCK(so).
64  * (c) locked by SOCKBUF_LOCK(&so->so_rcv).
65  * (d) locked by SOCKBUF_LOCK(&so->so_snd).
66  * (e) locked by ACCEPT_LOCK().
67  * (f) not locked since integer reads/writes are atomic.
68  * (g) used only as a sleep/wakeup address, no value.
69  * (h) locked by global mutex so_global_mtx.
70  */
71 struct socket {
72 	int	so_count;		/* (b) reference count */
73 	short	so_type;		/* (a) generic type, see socket.h */
74 	short	so_options;		/* from socket call, see socket.h */
75 	short	so_linger;		/* time to linger while closing */
76 	short	so_state;		/* (b) internal state flags SS_* */
77 	int	so_qstate;		/* (e) internal state flags SQ_* */
78 	void	*so_pcb;		/* protocol control block */
79 	struct	vnet *so_vnet;		/* network stack instance */
80 	struct	protosw *so_proto;	/* (a) protocol handle */
81 /*
82  * Variables for connection queuing.
83  * Socket where accepts occur is so_head in all subsidiary sockets.
84  * If so_head is 0, socket is not related to an accept.
85  * For head socket so_incomp queues partially completed connections,
86  * while so_comp is a queue of connections ready to be accepted.
87  * If a connection is aborted and it has so_head set, then
88  * it has to be pulled out of either so_incomp or so_comp.
89  * We allow connections to queue up based on current queue lengths
90  * and limit on number of queued connections for this socket.
91  */
92 	struct	socket *so_head;	/* (e) back pointer to listen socket */
93 	TAILQ_HEAD(, socket) so_incomp;	/* (e) queue of partial unaccepted connections */
94 	TAILQ_HEAD(, socket) so_comp;	/* (e) queue of complete unaccepted connections */
95 	TAILQ_ENTRY(socket) so_list;	/* (e) list of unaccepted connections */
96 	u_short	so_qlen;		/* (e) number of unaccepted connections */
97 	u_short	so_incqlen;		/* (e) number of unaccepted incomplete
98 					   connections */
99 	u_short	so_qlimit;		/* (e) max number queued connections */
100 	short	so_timeo;		/* (g) connection timeout */
101 	u_short	so_error;		/* (f) error affecting connection */
102 	struct	sigio *so_sigio;	/* [sg] information for async I/O or
103 					   out of band data (SIGURG) */
104 	u_long	so_oobmark;		/* (c) chars to oob mark */
105 	TAILQ_HEAD(, aiocblist) so_aiojobq; /* AIO ops waiting on socket */
106 
107 	struct sockbuf so_rcv, so_snd;
108 
109 	struct	ucred *so_cred;		/* (a) user credentials */
110 	struct	label *so_label;	/* (b) MAC label for socket */
111 	struct	label *so_peerlabel;	/* (b) cached MAC label for peer */
112 	/* NB: generation count must not be first. */
113 	so_gen_t so_gencnt;		/* (h) generation count */
114 	void	*so_emuldata;		/* (b) private data for emulators */
115  	struct so_accf {
116 		struct	accept_filter *so_accept_filter;
117 		void	*so_accept_filter_arg;	/* saved filter args */
118 		char	*so_accept_filter_str;	/* saved user args */
119 	} *so_accf;
120 	/*
121 	 * so_fibnum, so_user_cookie and friends can be used to attach
122 	 * some user-specified metadata to a socket, which then can be
123 	 * used by the kernel for various actions.
124 	 * so_user_cookie is used by ipfw/dummynet.
125 	 */
126 	int so_fibnum;		/* routing domain for this socket */
127 	uint32_t so_user_cookie;
128 };
129 
130 /*
131  * Global accept mutex to serialize access to accept queues and
132  * fields associated with multiple sockets.  This allows us to
133  * avoid defining a lock order between listen and accept sockets
134  * until such time as it proves to be a good idea.
135  */
136 extern struct mtx accept_mtx;
137 #define	ACCEPT_LOCK_ASSERT()		mtx_assert(&accept_mtx, MA_OWNED)
138 #define	ACCEPT_UNLOCK_ASSERT()		mtx_assert(&accept_mtx, MA_NOTOWNED)
139 #define	ACCEPT_LOCK()			mtx_lock(&accept_mtx)
140 #define	ACCEPT_UNLOCK()			mtx_unlock(&accept_mtx)
141 
142 /*
143  * Per-socket mutex: we reuse the receive socket buffer mutex for space
144  * efficiency.  This decision should probably be revisited as we optimize
145  * locking for the socket code.
146  */
147 #define	SOCK_MTX(_so)			SOCKBUF_MTX(&(_so)->so_rcv)
148 #define	SOCK_LOCK(_so)			SOCKBUF_LOCK(&(_so)->so_rcv)
149 #define	SOCK_OWNED(_so)			SOCKBUF_OWNED(&(_so)->so_rcv)
150 #define	SOCK_UNLOCK(_so)		SOCKBUF_UNLOCK(&(_so)->so_rcv)
151 #define	SOCK_LOCK_ASSERT(_so)		SOCKBUF_LOCK_ASSERT(&(_so)->so_rcv)
152 
153 /*
154  * Socket state bits stored in so_qstate.
155  */
156 #define	SQ_INCOMP		0x0800	/* unaccepted, incomplete connection */
157 #define	SQ_COMP			0x1000	/* unaccepted, complete connection */
158 
159 /*
160  * Externalized form of struct socket used by the sysctl(3) interface.
161  */
162 struct xsocket {
163 	size_t	xso_len;	/* length of this structure */
164 	struct	socket *xso_so;	/* makes a convenient handle sometimes */
165 	short	so_type;
166 	short	so_options;
167 	short	so_linger;
168 	short	so_state;
169 	caddr_t	so_pcb;		/* another convenient handle */
170 	int	xso_protocol;
171 	int	xso_family;
172 	u_short	so_qlen;
173 	u_short	so_incqlen;
174 	u_short	so_qlimit;
175 	short	so_timeo;
176 	u_short	so_error;
177 	pid_t	so_pgid;
178 	u_long	so_oobmark;
179 	struct xsockbuf so_rcv, so_snd;
180 	uid_t	so_uid;		/* XXX */
181 };
182 
183 #ifdef _KERNEL
184 
185 /*
186  * Macros for sockets and socket buffering.
187  */
188 
189 /*
190  * Flags to sblock().
191  */
192 #define	SBL_WAIT	0x00000001	/* Wait if not immediately available. */
193 #define	SBL_NOINTR	0x00000002	/* Force non-interruptible sleep. */
194 #define	SBL_VALID	(SBL_WAIT | SBL_NOINTR)
195 
196 /*
197  * Do we need to notify the other side when I/O is possible?
198  */
199 #define	sb_notify(sb)	(((sb)->sb_flags & (SB_WAIT | SB_SEL | SB_ASYNC | \
200     SB_UPCALL | SB_AIO | SB_KNOTE)) != 0)
201 
202 /* do we have to send all at once on a socket? */
203 #define	sosendallatonce(so) \
204     ((so)->so_proto->pr_flags & PR_ATOMIC)
205 
206 /* can we read something from so? */
207 #define	soreadabledata(so) \
208     ((so)->so_rcv.sb_cc >= (so)->so_rcv.sb_lowat || \
209 	!TAILQ_EMPTY(&(so)->so_comp) || (so)->so_error)
210 #define	soreadable(so) \
211 	(soreadabledata(so) || ((so)->so_rcv.sb_state & SBS_CANTRCVMORE))
212 
213 /* can we write something to so? */
214 #define	sowriteable(so) \
215     ((sbspace(&(so)->so_snd) >= (so)->so_snd.sb_lowat && \
216 	(((so)->so_state&SS_ISCONNECTED) || \
217 	  ((so)->so_proto->pr_flags&PR_CONNREQUIRED)==0)) || \
218      ((so)->so_snd.sb_state & SBS_CANTSENDMORE) || \
219      (so)->so_error)
220 
221 /*
222  * soref()/sorele() ref-count the socket structure.  Note that you must
223  * still explicitly close the socket, but the last ref count will free
224  * the structure.
225  */
226 #define	soref(so) do {							\
227 	SOCK_LOCK_ASSERT(so);						\
228 	++(so)->so_count;						\
229 } while (0)
230 
231 #define	sorele(so) do {							\
232 	ACCEPT_LOCK_ASSERT();						\
233 	SOCK_LOCK_ASSERT(so);						\
234 	if ((so)->so_count <= 0)					\
235 		panic("sorele");					\
236 	if (--(so)->so_count == 0)					\
237 		sofree(so);						\
238 	else {								\
239 		SOCK_UNLOCK(so);					\
240 		ACCEPT_UNLOCK();					\
241 	}								\
242 } while (0)
243 
244 /*
245  * In sorwakeup() and sowwakeup(), acquire the socket buffer lock to
246  * avoid a non-atomic test-and-wakeup.  However, sowakeup is
247  * responsible for releasing the lock if it is called.  We unlock only
248  * if we don't call into sowakeup.  If any code is introduced that
249  * directly invokes the underlying sowakeup() primitives, it must
250  * maintain the same semantics.
251  */
252 #define	sorwakeup_locked(so) do {					\
253 	SOCKBUF_LOCK_ASSERT(&(so)->so_rcv);				\
254 	if (sb_notify(&(so)->so_rcv))					\
255 		sowakeup((so), &(so)->so_rcv);	 			\
256 	else								\
257 		SOCKBUF_UNLOCK(&(so)->so_rcv);				\
258 } while (0)
259 
260 #define	sorwakeup(so) do {						\
261 	SOCKBUF_LOCK(&(so)->so_rcv);					\
262 	sorwakeup_locked(so);						\
263 } while (0)
264 
265 #define	sowwakeup_locked(so) do {					\
266 	SOCKBUF_LOCK_ASSERT(&(so)->so_snd);				\
267 	if (sb_notify(&(so)->so_snd))					\
268 		sowakeup((so), &(so)->so_snd); 				\
269 	else								\
270 		SOCKBUF_UNLOCK(&(so)->so_snd);				\
271 } while (0)
272 
273 #define	sowwakeup(so) do {						\
274 	SOCKBUF_LOCK(&(so)->so_snd);					\
275 	sowwakeup_locked(so);						\
276 } while (0)
277 
278 struct accept_filter {
279 	char	accf_name[16];
280 	int	(*accf_callback)
281 		(struct socket *so, void *arg, int waitflag);
282 	void *	(*accf_create)
283 		(struct socket *so, char *arg);
284 	void	(*accf_destroy)
285 		(struct socket *so);
286 	SLIST_ENTRY(accept_filter) accf_next;
287 };
288 
289 #ifdef MALLOC_DECLARE
290 MALLOC_DECLARE(M_ACCF);
291 MALLOC_DECLARE(M_PCB);
292 MALLOC_DECLARE(M_SONAME);
293 #endif
294 
295 extern int	maxsockets;
296 extern u_long	sb_max;
297 extern so_gen_t so_gencnt;
298 
299 struct mbuf;
300 struct sockaddr;
301 struct ucred;
302 struct uio;
303 
304 /* 'which' values for socket upcalls. */
305 #define	SO_RCV		1
306 #define	SO_SND		2
307 
308 /* Return values for socket upcalls. */
309 #define	SU_OK		0
310 #define	SU_ISCONNECTED	1
311 
312 /*
313  * From uipc_socket and friends
314  */
315 int	sockargs(struct mbuf **mp, caddr_t buf, int buflen, int type);
316 int	getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len);
317 void	soabort(struct socket *so);
318 int	soaccept(struct socket *so, struct sockaddr **nam);
319 int	socheckuid(struct socket *so, uid_t uid);
320 int	sobind(struct socket *so, struct sockaddr *nam, struct thread *td);
321 int	sobindat(int fd, struct socket *so, struct sockaddr *nam,
322 	    struct thread *td);
323 int	soclose(struct socket *so);
324 int	soconnect(struct socket *so, struct sockaddr *nam, struct thread *td);
325 int	soconnectat(int fd, struct socket *so, struct sockaddr *nam,
326 	    struct thread *td);
327 int	soconnect2(struct socket *so1, struct socket *so2);
328 int	socow_setup(struct mbuf *m0, struct uio *uio);
329 int	socreate(int dom, struct socket **aso, int type, int proto,
330 	    struct ucred *cred, struct thread *td);
331 int	sodisconnect(struct socket *so);
332 struct	sockaddr *sodupsockaddr(const struct sockaddr *sa, int mflags);
333 void	sofree(struct socket *so);
334 void	sohasoutofband(struct socket *so);
335 int	solisten(struct socket *so, int backlog, struct thread *td);
336 void	solisten_proto(struct socket *so, int backlog);
337 int	solisten_proto_check(struct socket *so);
338 struct socket *
339 	sonewconn(struct socket *head, int connstatus);
340 
341 
342 int	sopoll(struct socket *so, int events, struct ucred *active_cred,
343 	    struct thread *td);
344 int	sopoll_generic(struct socket *so, int events,
345 	    struct ucred *active_cred, struct thread *td);
346 int	soreceive(struct socket *so, struct sockaddr **paddr, struct uio *uio,
347 	    struct mbuf **mp0, struct mbuf **controlp, int *flagsp);
348 int	soreceive_stream(struct socket *so, struct sockaddr **paddr,
349 	    struct uio *uio, struct mbuf **mp0, struct mbuf **controlp,
350 	    int *flagsp);
351 int	soreceive_dgram(struct socket *so, struct sockaddr **paddr,
352 	    struct uio *uio, struct mbuf **mp0, struct mbuf **controlp,
353 	    int *flagsp);
354 int	soreceive_generic(struct socket *so, struct sockaddr **paddr,
355 	    struct uio *uio, struct mbuf **mp0, struct mbuf **controlp,
356 	    int *flagsp);
357 int	soreserve(struct socket *so, u_long sndcc, u_long rcvcc);
358 void	sorflush(struct socket *so);
359 int	sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
360 	    struct mbuf *top, struct mbuf *control, int flags,
361 	    struct thread *td);
362 int	sosend_dgram(struct socket *so, struct sockaddr *addr,
363 	    struct uio *uio, struct mbuf *top, struct mbuf *control,
364 	    int flags, struct thread *td);
365 int	sosend_generic(struct socket *so, struct sockaddr *addr,
366 	    struct uio *uio, struct mbuf *top, struct mbuf *control,
367 	    int flags, struct thread *td);
368 int	soshutdown(struct socket *so, int how);
369 void	sotoxsocket(struct socket *so, struct xsocket *xso);
370 void	soupcall_clear(struct socket *so, int which);
371 void	soupcall_set(struct socket *so, int which,
372 	    int (*func)(struct socket *, void *, int), void *arg);
373 void	sowakeup(struct socket *so, struct sockbuf *sb);
374 int	selsocket(struct socket *so, int events, struct timeval *tv,
375 	    struct thread *td);
376 
377 /*
378  * Accept filter functions (duh).
379  */
380 int	accept_filt_add(struct accept_filter *filt);
381 int	accept_filt_del(char *name);
382 struct	accept_filter *accept_filt_get(char *name);
383 #ifdef ACCEPT_FILTER_MOD
384 #ifdef SYSCTL_DECL
385 SYSCTL_DECL(_net_inet_accf);
386 #endif
387 int	accept_filt_generic_mod_event(module_t mod, int event, void *data);
388 #endif
389 
390 #endif /* _KERNEL */
391 
392 #endif /* !_SYS_SOCKETVAR_H_ */
393