socketvar.h revision 130398
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 * $FreeBSD: head/sys/sys/socketvar.h 130398 2004-06-13 02:50:07Z rwatson $
31 */
32
33#ifndef _SYS_SOCKETVAR_H_
34#define _SYS_SOCKETVAR_H_
35
36#include <sys/queue.h>			/* for TAILQ macros */
37#include <sys/selinfo.h>		/* for struct selinfo */
38#include <sys/_lock.h>
39#include <sys/_mutex.h>
40
41/*
42 * Kernel structure per socket.
43 * Contains send and receive buffer queues,
44 * handle on protocol and pointer to protocol
45 * private data and error information.
46 */
47typedef	u_quad_t so_gen_t;
48
49/*-
50 * Locking key to struct socket:
51 * (a) constant after allocation, no locking required.
52 * (b) locked by SOCK_LOCK(so).
53 * (c) locked by SOCKBUF_LOCK(&so->so_rcv).
54 * (d) locked by SOCKBUF_LOCK(&so->so_snd).
55 * (e) locked by ACCEPT_LOCK().
56 * (f) not locked since integer reads/writes are atomic.
57 * (g) used only as a sleep/wakeup address, no value.
58 */
59struct socket {
60	int	so_count;		/* (b) reference count */
61	short	so_type;		/* (a) generic type, see socket.h */
62	short	so_options;		/* from socket call, see socket.h */
63	short	so_linger;		/* time to linger while closing */
64	short	so_state;		/* internal state flags SS_* */
65	int	so_qstate;		/* (e) internal state flags SQ_* */
66	void	*so_pcb;		/* protocol control block */
67	struct	protosw *so_proto;	/* (a) protocol handle */
68/*
69 * Variables for connection queuing.
70 * Socket where accepts occur is so_head in all subsidiary sockets.
71 * If so_head is 0, socket is not related to an accept.
72 * For head socket so_incomp queues partially completed connections,
73 * while so_comp is a queue of connections ready to be accepted.
74 * If a connection is aborted and it has so_head set, then
75 * it has to be pulled out of either so_incomp or so_comp.
76 * We allow connections to queue up based on current queue lengths
77 * and limit on number of queued connections for this socket.
78 */
79	struct	socket *so_head;	/* (e) back pointer to accept socket */
80	TAILQ_HEAD(, socket) so_incomp;	/* (e) queue of partial unaccepted connections */
81	TAILQ_HEAD(, socket) so_comp;	/* (e) queue of complete unaccepted connections */
82	TAILQ_ENTRY(socket) so_list;	/* (e) list of unaccepted connections */
83	short	so_qlen;		/* (e) number of unaccepted connections */
84	short	so_incqlen;		/* (e) number of unaccepted incomplete
85					   connections */
86	short	so_qlimit;		/* (e) max number queued connections */
87	short	so_timeo;		/* connection timeout */
88	u_short	so_error;		/* error affecting connection */
89	struct	sigio *so_sigio;	/* [sg] information for async I/O or
90					   out of band data (SIGURG) */
91	u_long	so_oobmark;		/* chars to oob mark */
92	TAILQ_HEAD(, aiocblist) so_aiojobq; /* AIO ops waiting on socket */
93/*
94 * Variables for socket buffering.
95 */
96	struct sockbuf {
97		struct	selinfo sb_sel;	/* process selecting read/write */
98		struct	mtx sb_mtx;	/* sockbuf lock */
99#define	sb_startzero	sb_mb
100		struct	mbuf *sb_mb;	/* the mbuf chain */
101		struct	mbuf *sb_mbtail; /* the last mbuf in the chain */
102		struct	mbuf *sb_lastrecord;	/* first mbuf of last record in
103						 * socket buffer */
104		u_int	sb_cc;		/* actual chars in buffer */
105		u_int	sb_hiwat;	/* max actual char count */
106		u_int	sb_mbcnt;	/* chars of mbufs used */
107		u_int	sb_mbmax;	/* max chars of mbufs to use */
108		u_int	sb_ctl;		/* non-data chars in buffer */
109		int	sb_lowat;	/* low water mark */
110		int	sb_timeo;	/* timeout for read/write */
111		short	sb_flags;	/* flags, see below */
112	} so_rcv, so_snd;
113#define	SB_MAX		(256*1024)	/* default for max chars in sockbuf */
114#define	SB_LOCK		0x01		/* lock on data queue */
115#define	SB_WANT		0x02		/* someone is waiting to lock */
116#define	SB_WAIT		0x04		/* someone is waiting for data/space */
117#define	SB_SEL		0x08		/* someone is selecting */
118#define	SB_ASYNC	0x10		/* ASYNC I/O, need signals */
119#define	SB_UPCALL	0x20		/* someone wants an upcall */
120#define	SB_NOINTR	0x40		/* operations not interruptible */
121#define SB_AIO		0x80		/* AIO operations queued */
122#define SB_KNOTE	0x100		/* kernel note attached */
123
124	void	(*so_upcall)(struct socket *, void *, int);
125	void	*so_upcallarg;
126	struct	ucred *so_cred;		/* user credentials */
127	struct	label *so_label;	/* (b) MAC label for socket */
128	struct	label *so_peerlabel;	/* (b) cached MAC label for peer */
129	/* NB: generation count must not be first; easiest to make it last. */
130	so_gen_t so_gencnt;		/* generation count */
131	void	*so_emuldata;		/* private data for emulators */
132 	struct so_accf {
133		struct	accept_filter *so_accept_filter;
134		void	*so_accept_filter_arg;	/* saved filter args */
135		char	*so_accept_filter_str;	/* saved user args */
136	} *so_accf;
137};
138
139#define SB_EMPTY_FIXUP(sb) do {						\
140	if ((sb)->sb_mb == NULL) {					\
141		(sb)->sb_mbtail = NULL;					\
142		(sb)->sb_lastrecord = NULL;				\
143	}								\
144} while (/*CONSTCOND*/0)
145
146/*
147 * Global accept mutex to serialize access to accept queues and
148 * fields associated with multiple sockets.  This allows us to
149 * avoid defining a lock order between listen and accept sockets
150 * until such time as it proves to be a good idea.
151 */
152extern struct mtx accept_mtx;
153#define	ACCEPT_LOCK()			mtx_lock(&accept_mtx)
154#define	ACCEPT_UNLOCK()			mtx_unlock(&accept_mtx)
155
156/*
157 * Per-socket buffer mutex used to protect most fields in the socket
158 * buffer.
159 */
160#define	SOCKBUF_MTX(_sb)		(&(_sb)->sb_mtx)
161#define	SOCKBUF_LOCK_INIT(_sb, _name) \
162	mtx_init(SOCKBUF_MTX(_sb), _name, NULL, MTX_DEF)
163#define	SOCKBUF_LOCK_DESTROY(_sb)	mtx_destroy(SOCKBUF_MTX(_sb))
164#define	SOCKBUF_LOCK(_sb)		mtx_lock(SOCKBUF_MTX(_sb))
165#define	SOCKBUF_OWNED(_sb)		mtx_owned(SOCKBUF_MTX(_sb))
166#define	SOCKBUF_UNLOCK(_sb)		mtx_unlock(SOCKBUF_MTX(_sb))
167#define	SOCKBUF_LOCK_ASSERT(_sb)	mtx_assert(SOCKBUF_MTX(_sb), MA_OWNED)
168
169/*
170 * Per-socket mutex: we reuse the receive socket buffer mutex for space
171 * efficiency.  This decision should probably be revisited as we optimize
172 * locking for the socket code.
173 */
174#define	SOCK_MTX(_so)			SOCKBUF_MTX(&(_so)->so_rcv)
175#define	SOCK_LOCK(_so)			SOCKBUF_LOCK(&(_so)->so_rcv)
176#define	SOCK_OWNED(_so)			SOCKBUF_OWNED(&(_so)->so_rcv)
177#define	SOCK_UNLOCK(_so)		SOCKBUF_UNLOCK(&(_so)->so_rcv)
178#define	SOCK_LOCK_ASSERT(_so)		SOCKBUF_LOCK_ASSERT(&(_so)->so_rcv)
179
180/*
181 * Socket state bits.
182 */
183#define	SS_NOFDREF		0x0001	/* no file table ref any more */
184#define	SS_ISCONNECTED		0x0002	/* socket connected to a peer */
185#define	SS_ISCONNECTING		0x0004	/* in process of connecting to peer */
186#define	SS_ISDISCONNECTING	0x0008	/* in process of disconnecting */
187#define	SS_CANTSENDMORE		0x0010	/* can't send more data to peer */
188#define	SS_CANTRCVMORE		0x0020	/* can't receive more data from peer */
189#define	SS_RCVATMARK		0x0040	/* at mark on input */
190
191#define	SS_NBIO			0x0100	/* non-blocking ops */
192#define	SS_ASYNC		0x0200	/* async i/o notify */
193#define	SS_ISCONFIRMING		0x0400	/* deciding to accept connection req */
194
195#define	SS_ISDISCONNECTED	0x2000	/* socket disconnected from peer */
196
197/*
198 * Socket state bits stored in so_qstate.
199 */
200#define	SQ_INCOMP		0x0800	/* unaccepted, incomplete connection */
201#define	SQ_COMP			0x1000	/* unaccepted, complete connection */
202
203/*
204 * Externalized form of struct socket used by the sysctl(3) interface.
205 */
206struct xsocket {
207	size_t	xso_len;	/* length of this structure */
208	struct	socket *xso_so;	/* makes a convenient handle sometimes */
209	short	so_type;
210	short	so_options;
211	short	so_linger;
212	short	so_state;
213	caddr_t	so_pcb;		/* another convenient handle */
214	int	xso_protocol;
215	int	xso_family;
216	short	so_qlen;
217	short	so_incqlen;
218	short	so_qlimit;
219	short	so_timeo;
220	u_short	so_error;
221	pid_t	so_pgid;
222	u_long	so_oobmark;
223	struct xsockbuf {
224		u_int	sb_cc;
225		u_int	sb_hiwat;
226		u_int	sb_mbcnt;
227		u_int	sb_mbmax;
228		int	sb_lowat;
229		int	sb_timeo;
230		short	sb_flags;
231	} so_rcv, so_snd;
232	uid_t	so_uid;		/* XXX */
233};
234
235#ifdef _KERNEL
236
237/*
238 * Macros for sockets and socket buffering.
239 */
240
241/*
242 * Do we need to notify the other side when I/O is possible?
243 */
244#define	sb_notify(sb)	(((sb)->sb_flags & (SB_WAIT | SB_SEL | SB_ASYNC | \
245    SB_UPCALL | SB_AIO | SB_KNOTE)) != 0)
246
247/*
248 * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
249 * This is problematical if the fields are unsigned, as the space might
250 * still be negative (cc > hiwat or mbcnt > mbmax).  Should detect
251 * overflow and return 0.  Should use "lmin" but it doesn't exist now.
252 */
253#define	sbspace(sb) \
254    ((long) imin((int)((sb)->sb_hiwat - (sb)->sb_cc), \
255	 (int)((sb)->sb_mbmax - (sb)->sb_mbcnt)))
256
257/* do we have to send all at once on a socket? */
258#define	sosendallatonce(so) \
259    ((so)->so_proto->pr_flags & PR_ATOMIC)
260
261/* can we read something from so? */
262#define	soreadable(so) \
263    ((so)->so_rcv.sb_cc >= (so)->so_rcv.sb_lowat || \
264	((so)->so_state & SS_CANTRCVMORE) || \
265	!TAILQ_EMPTY(&(so)->so_comp) || (so)->so_error)
266
267/* can we write something to so? */
268#define	sowriteable(so) \
269    ((sbspace(&(so)->so_snd) >= (so)->so_snd.sb_lowat && \
270	(((so)->so_state&SS_ISCONNECTED) || \
271	  ((so)->so_proto->pr_flags&PR_CONNREQUIRED)==0)) || \
272     ((so)->so_state & SS_CANTSENDMORE) || \
273     (so)->so_error)
274
275/* adjust counters in sb reflecting allocation of m */
276#define	sballoc(sb, m) { \
277	(sb)->sb_cc += (m)->m_len; \
278	if ((m)->m_type != MT_DATA && (m)->m_type != MT_HEADER && \
279	    (m)->m_type != MT_OOBDATA) \
280		(sb)->sb_ctl += (m)->m_len; \
281	(sb)->sb_mbcnt += MSIZE; \
282	if ((m)->m_flags & M_EXT) \
283		(sb)->sb_mbcnt += (m)->m_ext.ext_size; \
284}
285
286/* adjust counters in sb reflecting freeing of m */
287#define	sbfree(sb, m) { \
288	(sb)->sb_cc -= (m)->m_len; \
289	if ((m)->m_type != MT_DATA && (m)->m_type != MT_HEADER && \
290	    (m)->m_type != MT_OOBDATA) \
291		(sb)->sb_ctl -= (m)->m_len; \
292	(sb)->sb_mbcnt -= MSIZE; \
293	if ((m)->m_flags & M_EXT) \
294		(sb)->sb_mbcnt -= (m)->m_ext.ext_size; \
295}
296
297/*
298 * Set lock on sockbuf sb; sleep if lock is already held.
299 * Unless SB_NOINTR is set on sockbuf, sleep is interruptible.
300 * Returns error without lock if sleep is interrupted.
301 */
302#define sblock(sb, wf) ((sb)->sb_flags & SB_LOCK ? \
303		(((wf) == M_WAITOK) ? sb_lock(sb) : EWOULDBLOCK) : \
304		((sb)->sb_flags |= SB_LOCK), 0)
305
306/* release lock on sockbuf sb */
307#define	sbunlock(sb) { \
308	(sb)->sb_flags &= ~SB_LOCK; \
309	if ((sb)->sb_flags & SB_WANT) { \
310		(sb)->sb_flags &= ~SB_WANT; \
311		wakeup(&(sb)->sb_flags); \
312	} \
313}
314
315/*
316 * soref()/sorele() ref-count the socket structure.  Note that you must
317 * still explicitly close the socket, but the last ref count will free
318 * the structure.
319 */
320#define	soref(so) do {							\
321	SOCK_LOCK_ASSERT(so);						\
322	++(so)->so_count;						\
323} while (0)
324
325#define	sorele(so) do {							\
326	SOCK_LOCK_ASSERT(so);						\
327	if ((so)->so_count <= 0)					\
328		panic("sorele");					\
329	if (--(so)->so_count == 0)					\
330		sofree(so);						\
331	else								\
332		SOCK_UNLOCK(so);					\
333} while (0)
334
335#define	sotryfree(so) do {						\
336	SOCK_LOCK_ASSERT(so);						\
337	if ((so)->so_count == 0)					\
338		sofree(so);						\
339	else								\
340		SOCK_UNLOCK(so);					\
341} while(0)
342
343#define	sorwakeup(so) do {						\
344	if (sb_notify(&(so)->so_rcv))					\
345		sowakeup((so), &(so)->so_rcv); 				\
346} while (0)
347
348#define	sowwakeup(so) do {						\
349	if (sb_notify(&(so)->so_snd))					\
350		sowakeup((so), &(so)->so_snd); 				\
351} while (0)
352
353/*
354 * Argument structure for sosetopt et seq.  This is in the KERNEL
355 * section because it will never be visible to user code.
356 */
357enum sopt_dir { SOPT_GET, SOPT_SET };
358struct sockopt {
359	enum	sopt_dir sopt_dir; /* is this a get or a set? */
360	int	sopt_level;	/* second arg of [gs]etsockopt */
361	int	sopt_name;	/* third arg of [gs]etsockopt */
362	void   *sopt_val;	/* fourth arg of [gs]etsockopt */
363	size_t	sopt_valsize;	/* (almost) fifth arg of [gs]etsockopt */
364	struct	thread *sopt_td; /* calling thread or null if kernel */
365};
366
367struct accept_filter {
368	char	accf_name[16];
369	void	(*accf_callback)
370		(struct socket *so, void *arg, int waitflag);
371	void *	(*accf_create)
372		(struct socket *so, char *arg);
373	void	(*accf_destroy)
374		(struct socket *so);
375	SLIST_ENTRY(accept_filter) accf_next;
376};
377
378#ifdef MALLOC_DECLARE
379MALLOC_DECLARE(M_ACCF);
380MALLOC_DECLARE(M_PCB);
381MALLOC_DECLARE(M_SONAME);
382#endif
383
384extern int	maxsockets;
385extern u_long	sb_max;
386extern struct uma_zone *socket_zone;
387extern so_gen_t so_gencnt;
388
389struct mbuf;
390struct sockaddr;
391struct ucred;
392struct uio;
393
394/*
395 * From uipc_socket and friends
396 */
397int	sockargs(struct mbuf **mp, caddr_t buf, int buflen, int type);
398int	getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len);
399void	sbappend(struct sockbuf *sb, struct mbuf *m);
400void	sbappendstream(struct sockbuf *sb, struct mbuf *m);
401int	sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
402	    struct mbuf *m0, struct mbuf *control);
403int	sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
404	    struct mbuf *control);
405void	sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
406void	sbcheck(struct sockbuf *sb);
407void	sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
408struct mbuf *
409	sbcreatecontrol(caddr_t p, int size, int type, int level);
410void	sbdrop(struct sockbuf *sb, int len);
411void	sbdroprecord(struct sockbuf *sb);
412void	sbflush(struct sockbuf *sb);
413void	sbinsertoob(struct sockbuf *sb, struct mbuf *m0);
414void	sbrelease(struct sockbuf *sb, struct socket *so);
415int	sbreserve(struct sockbuf *sb, u_long cc, struct socket *so,
416	    struct thread *td);
417void	sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb);
418int	sbwait(struct sockbuf *sb);
419int	sb_lock(struct sockbuf *sb);
420int	soabort(struct socket *so);
421int	soaccept(struct socket *so, struct sockaddr **nam);
422struct	socket *soalloc(int mflags);
423int	socheckuid(struct socket *so, uid_t uid);
424int	sobind(struct socket *so, struct sockaddr *nam, struct thread *td);
425void	socantrcvmore(struct socket *so);
426void	socantsendmore(struct socket *so);
427int	soclose(struct socket *so);
428int	soconnect(struct socket *so, struct sockaddr *nam, struct thread *td);
429int	soconnect2(struct socket *so1, struct socket *so2);
430int	socow_setup(struct mbuf *m0, struct uio *uio);
431int	socreate(int dom, struct socket **aso, int type, int proto,
432	    struct ucred *cred, struct thread *td);
433void	sodealloc(struct socket *so);
434int	sodisconnect(struct socket *so);
435struct	sockaddr *sodupsockaddr(const struct sockaddr *sa, int mflags);
436void	sofree(struct socket *so);
437int	sogetopt(struct socket *so, struct sockopt *sopt);
438void	sohasoutofband(struct socket *so);
439void	soisconnected(struct socket *so);
440void	soisconnecting(struct socket *so);
441void	soisdisconnected(struct socket *so);
442void	soisdisconnecting(struct socket *so);
443int	solisten(struct socket *so, int backlog, struct thread *td);
444struct socket *
445	sonewconn(struct socket *head, int connstatus);
446int	sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen);
447int	sooptcopyout(struct sockopt *sopt, const void *buf, size_t len);
448
449/* XXX; prepare mbuf for (__FreeBSD__ < 3) routines. */
450int	soopt_getm(struct sockopt *sopt, struct mbuf **mp);
451int	soopt_mcopyin(struct sockopt *sopt, struct mbuf *m);
452int	soopt_mcopyout(struct sockopt *sopt, struct mbuf *m);
453
454int	sopoll(struct socket *so, int events, struct ucred *active_cred,
455	    struct thread *td);
456int	soreceive(struct socket *so, struct sockaddr **paddr, struct uio *uio,
457	    struct mbuf **mp0, struct mbuf **controlp, int *flagsp);
458int	soreserve(struct socket *so, u_long sndcc, u_long rcvcc);
459void	sorflush(struct socket *so);
460int	sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
461	    struct mbuf *top, struct mbuf *control, int flags,
462	    struct thread *td);
463int	sosetopt(struct socket *so, struct sockopt *sopt);
464int	soshutdown(struct socket *so, int how);
465void	sotoxsocket(struct socket *so, struct xsocket *xso);
466void	sowakeup(struct socket *so, struct sockbuf *sb);
467
468#ifdef SOCKBUF_DEBUG
469void	sblastrecordchk(struct sockbuf *, const char *, int);
470#define	SBLASTRECORDCHK(sb)	sblastrecordchk((sb), __FILE__, __LINE__)
471
472void	sblastmbufchk(struct sockbuf *, const char *, int);
473#define	SBLASTMBUFCHK(sb)	sblastmbufchk((sb), __FILE__, __LINE__)
474#else
475#define	SBLASTRECORDCHK(sb)      /* nothing */
476#define	SBLASTMBUFCHK(sb)        /* nothing */
477#endif /* SOCKBUF_DEBUG */
478
479/*
480 * Accept filter functions (duh).
481 */
482int	accept_filt_add(struct accept_filter *filt);
483int	accept_filt_del(char *name);
484struct	accept_filter *accept_filt_get(char *name);
485#ifdef ACCEPT_FILTER_MOD
486#ifdef SYSCTL_DECL
487SYSCTL_DECL(_net_inet_accf);
488#endif
489int	accept_filt_generic_mod_event(module_t mod, int event, void *data);
490#endif
491
492#endif /* _KERNEL */
493
494#endif /* !_SYS_SOCKETVAR_H_ */
495