recvbuff.h revision 290001 
1#ifndef RECVBUFF_H
2#define RECVBUFF_H
3
4#include "ntp.h"
5#include "ntp_net.h"
6#include "ntp_lists.h"
7
8#include <isc/result.h>
9
10/*
11 * recvbuf memory management
12 */
13#define RECV_INIT	10	/* 10 buffers initially */
14#define RECV_LOWAT	3	/* when we're down to three buffers get more */
15#define RECV_INC	5	/* get 5 more at a time */
16#define RECV_TOOMANY	40	/* this is way too many buffers */
17
18#if defined HAVE_IO_COMPLETION_PORT
19# include "ntp_iocompletionport.h"
20# include "ntp_timer.h"
21
22# define RECV_BLOCK_IO()	EnterCriticalSection(&RecvCritSection)
23# define RECV_UNBLOCK_IO()	LeaveCriticalSection(&RecvCritSection)
24
25/*  Return the event which is set when items are added to the full list
26 */
27extern HANDLE	get_recv_buff_event(void);
28#else
29# define RECV_BLOCK_IO()
30# define RECV_UNBLOCK_IO()
31#endif
32
33
34/*
35 * Format of a recvbuf.  These are used by the asynchronous receive
36 * routine to store incoming packets and related information.
37 */
38
39/*
40 *  the maximum length NTP packet contains the NTP header, one Autokey
41 *  request, one Autokey response and the MAC. Assuming certificates don't
42 *  get too big, the maximum packet length is set arbitrarily at 1000.
43 */
44#define	RX_BUFF_SIZE	1000		/* hail Mary */
45
46
47typedef struct recvbuf recvbuf_t;
48
49struct recvbuf {
50	recvbuf_t *	link;	/* next in list */
51	union {
52		sockaddr_u	X_recv_srcadr;
53		caddr_t		X_recv_srcclock;
54		struct peer *	X_recv_peer;
55	} X_from_where;
56#define recv_srcadr		X_from_where.X_recv_srcadr
57#define	recv_srcclock		X_from_where.X_recv_srcclock
58#define recv_peer		X_from_where.X_recv_peer
59#ifndef HAVE_IO_COMPLETION_PORT
60	sockaddr_u	srcadr;		/* where packet came from */
61#else
62	int		recv_srcadr_len;/* filled in on completion */
63#endif
64	endpt *		dstadr;		/* address pkt arrived on */
65	SOCKET		fd;		/* fd on which it was received */
66	int		msg_flags;	/* Flags received about the packet */
67	l_fp		recv_time;	/* time of arrival */
68	void		(*receiver)(struct recvbuf *); /* callback */
69	int		recv_length;	/* number of octets received */
70	union {
71		struct pkt	X_recv_pkt;
72		u_char		X_recv_buffer[RX_BUFF_SIZE];
73	} recv_space;
74#define	recv_pkt		recv_space.X_recv_pkt
75#define	recv_buffer		recv_space.X_recv_buffer
76	int used;		/* reference count */
77};
78
79extern	void	init_recvbuff(int);
80
81/* freerecvbuf - make a single recvbuf available for reuse
82 */
83extern	void	freerecvbuf(struct recvbuf *);
84
85/*  Get a free buffer (typically used so an async
86 *  read can directly place data into the buffer
87 *
88 *  The buffer is removed from the free list. Make sure
89 *  you put it back with freerecvbuf() or
90 */
91
92/* signal safe - no malloc */
93extern	struct recvbuf *get_free_recv_buffer(void);
94/* signal unsafe - may malloc */
95extern	struct recvbuf *get_free_recv_buffer_alloc(void);
96
97/*   Add a buffer to the full list
98 */
99extern	void	add_full_recv_buffer(struct recvbuf *);
100
101/* number of recvbufs on freelist */
102extern u_long free_recvbuffs(void);
103extern u_long full_recvbuffs(void);
104extern u_long total_recvbuffs(void);
105extern u_long lowater_additions(void);
106
107/*  Returns the next buffer in the full list.
108 *
109 */
110extern	struct recvbuf *get_full_recv_buffer(void);
111
112/*
113 * purge_recv_buffers_for_fd() - purges any previously-received input
114 *				 from a given file descriptor.
115 */
116extern	void purge_recv_buffers_for_fd(SOCKET);
117
118/*
119 * Checks to see if there are buffers to process
120 */
121extern isc_boolean_t has_full_recv_buffer(void);
122
123#endif	/* RECVBUFF_H */
124