recvbuff.h revision 330567 
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 1200.
43 *  (was 1000, but that bumps on 2048 RSA keys)
44 */
45#define	RX_BUFF_SIZE	1200		/* hail Mary */
46
47
48typedef struct recvbuf recvbuf_t;
49
50struct recvbuf {
51	recvbuf_t *	link;	/* next in list */
52	union {
53		sockaddr_u	X_recv_srcadr;
54		caddr_t		X_recv_srcclock;
55		struct peer *	X_recv_peer;
56	} X_from_where;
57#define recv_srcadr		X_from_where.X_recv_srcadr
58#define	recv_srcclock		X_from_where.X_recv_srcclock
59#define recv_peer		X_from_where.X_recv_peer
60#ifndef HAVE_IO_COMPLETION_PORT
61	sockaddr_u	srcadr;		/* where packet came from */
62#else
63	int		recv_srcadr_len;/* filled in on completion */
64#endif
65	endpt *		dstadr;		/* address pkt arrived on */
66	SOCKET		fd;		/* fd on which it was received */
67	int		msg_flags;	/* Flags received about the packet */
68	l_fp		recv_time;	/* time of arrival */
69	void		(*receiver)(struct recvbuf *); /* callback */
70	int		recv_length;	/* number of octets received */
71	union {
72		struct pkt	X_recv_pkt;
73		u_char		X_recv_buffer[RX_BUFF_SIZE];
74	} recv_space;
75#define	recv_pkt		recv_space.X_recv_pkt
76#define	recv_buffer		recv_space.X_recv_buffer
77	int used;		/* reference count */
78};
79
80extern	void	init_recvbuff(int);
81
82/* freerecvbuf - make a single recvbuf available for reuse
83 */
84extern	void	freerecvbuf(struct recvbuf *);
85
86/*  Get a free buffer (typically used so an async
87 *  read can directly place data into the buffer
88 *
89 *  The buffer is removed from the free list. Make sure
90 *  you put it back with freerecvbuf() or
91 */
92
93/* signal safe - no malloc */
94extern	struct recvbuf *get_free_recv_buffer(void);
95/* signal unsafe - may malloc, never returs NULL */
96extern	struct recvbuf *get_free_recv_buffer_alloc(void);
97
98/*   Add a buffer to the full list
99 */
100extern	void	add_full_recv_buffer(struct recvbuf *);
101
102/* number of recvbufs on freelist */
103extern u_long free_recvbuffs(void);
104extern u_long full_recvbuffs(void);
105extern u_long total_recvbuffs(void);
106extern u_long lowater_additions(void);
107
108/*  Returns the next buffer in the full list.
109 *
110 */
111extern	struct recvbuf *get_full_recv_buffer(void);
112
113/*
114 * purge_recv_buffers_for_fd() - purges any previously-received input
115 *				 from a given file descriptor.
116 */
117extern	void purge_recv_buffers_for_fd(int);
118
119/*
120 * Checks to see if there are buffers to process
121 */
122extern isc_boolean_t has_full_recv_buffer(void);
123
124#endif	/* RECVBUFF_H */
125