xref: /netbsd-src/external/bsd/ntp/dist/include/recvbuff.h (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: recvbuff.h,v 1.1.1.3 2013/12/27 23:30:45 christos Exp $	*/
2 
3 #ifndef RECVBUFF_H
4 #define RECVBUFF_H
5 
6 #include "ntp.h"
7 #include "ntp_net.h"
8 #include "ntp_lists.h"
9 
10 #include <isc/result.h>
11 
12 /*
13  * recvbuf memory management
14  */
15 #define RECV_INIT	10	/* 10 buffers initially */
16 #define RECV_LOWAT	3	/* when we're down to three buffers get more */
17 #define RECV_INC	5	/* get 5 more at a time */
18 #define RECV_TOOMANY	40	/* this is way too many buffers */
19 
20 #if defined HAVE_IO_COMPLETION_PORT
21 # include "ntp_iocompletionport.h"
22 # include "ntp_timer.h"
23 
24 # define RECV_BLOCK_IO()	EnterCriticalSection(&RecvCritSection)
25 # define RECV_UNBLOCK_IO()	LeaveCriticalSection(&RecvCritSection)
26 
27 /*  Return the event which is set when items are added to the full list
28  */
29 extern HANDLE	get_recv_buff_event(void);
30 #else
31 # define RECV_BLOCK_IO()
32 # define RECV_UNBLOCK_IO()
33 #endif
34 
35 
36 /*
37  * Format of a recvbuf.  These are used by the asynchronous receive
38  * routine to store incoming packets and related information.
39  */
40 
41 /*
42  *  the maximum length NTP packet contains the NTP header, one Autokey
43  *  request, one Autokey response and the MAC. Assuming certificates don't
44  *  get too big, the maximum packet length is set arbitrarily at 1000.
45  */
46 #define	RX_BUFF_SIZE	1000		/* hail Mary */
47 
48 
49 typedef struct recvbuf recvbuf_t;
50 
51 struct recvbuf {
52 	recvbuf_t *	link;	/* next in list */
53 	union {
54 		sockaddr_u	X_recv_srcadr;
55 		caddr_t		X_recv_srcclock;
56 		struct peer *	X_recv_peer;
57 	} X_from_where;
58 #define recv_srcadr		X_from_where.X_recv_srcadr
59 #define	recv_srcclock		X_from_where.X_recv_srcclock
60 #define recv_peer		X_from_where.X_recv_peer
61 #ifndef HAVE_IO_COMPLETION_PORT
62 	sockaddr_u	srcadr;		/* where packet came from */
63 #else
64 	int		recv_srcadr_len;/* filled in on completion */
65 #endif
66 	endpt *		dstadr;		/* address pkt arrived on */
67 	SOCKET		fd;		/* fd on which it was received */
68 	int		msg_flags;	/* Flags received about the packet */
69 	l_fp		recv_time;	/* time of arrival */
70 	void		(*receiver)(struct recvbuf *); /* callback */
71 	int		recv_length;	/* number of octets received */
72 	union {
73 		struct pkt	X_recv_pkt;
74 		u_char		X_recv_buffer[RX_BUFF_SIZE];
75 	} recv_space;
76 #define	recv_pkt		recv_space.X_recv_pkt
77 #define	recv_buffer		recv_space.X_recv_buffer
78 	int used;		/* reference count */
79 };
80 
81 extern	void	init_recvbuff(int);
82 
83 /* freerecvbuf - make a single recvbuf available for reuse
84  */
85 extern	void	freerecvbuf(struct recvbuf *);
86 
87 /*  Get a free buffer (typically used so an async
88  *  read can directly place data into the buffer
89  *
90  *  The buffer is removed from the free list. Make sure
91  *  you put it back with freerecvbuf() or
92  */
93 
94 /* signal safe - no malloc */
95 extern	struct recvbuf *get_free_recv_buffer(void);
96 /* signal unsafe - may malloc */
97 extern	struct recvbuf *get_free_recv_buffer_alloc(void);
98 
99 /*   Add a buffer to the full list
100  */
101 extern	void	add_full_recv_buffer(struct recvbuf *);
102 
103 /* number of recvbufs on freelist */
104 extern u_long free_recvbuffs(void);
105 extern u_long full_recvbuffs(void);
106 extern u_long total_recvbuffs(void);
107 extern u_long lowater_additions(void);
108 
109 /*  Returns the next buffer in the full list.
110  *
111  */
112 extern	struct recvbuf *get_full_recv_buffer(void);
113 
114 /*
115  * purge_recv_buffers_for_fd() - purges any previously-received input
116  *				 from a given file descriptor.
117  */
118 extern	void purge_recv_buffers_for_fd(SOCKET);
119 
120 /*
121  * Checks to see if there are buffers to process
122  */
123 extern isc_boolean_t has_full_recv_buffer(void);
124 
125 #endif	/* RECVBUFF_H */
126