projects/linux·blob v2.6.30-rc6 · refs

112 lines · 3.6 KiB

1#ifndef _LINUX_MSG_H
2#define _LINUX_MSG_H
3
4#include <linux/ipc.h>
5
6/* ipcs ctl commands */
7#define MSG_STAT 11
8#define MSG_INFO 12
9
10/* msgrcv options */
11#define MSG_NOERROR 010000 /* no error if message is too big */
12#define MSG_EXCEPT 020000 /* recv any msg except of specified type.*/
13
14/* Obsolete, used only for backwards compatibility and libc5 compiles */
15struct msqid_ds {
16 struct ipc_perm msg_perm;
17 struct msg *msg_first; /* first message on queue,unused */
18 struct msg *msg_last; /* last message in queue,unused */
19 __kernel_time_t msg_stime; /* last msgsnd time */
20 __kernel_time_t msg_rtime; /* last msgrcv time */
21 __kernel_time_t msg_ctime; /* last change time */
22 unsigned long msg_lcbytes; /* Reuse junk fields for 32 bit */
23 unsigned long msg_lqbytes; /* ditto */
24 unsigned short msg_cbytes; /* current number of bytes on queue */
25 unsigned short msg_qnum; /* number of messages in queue */
26 unsigned short msg_qbytes; /* max number of bytes on queue */
27 __kernel_ipc_pid_t msg_lspid; /* pid of last msgsnd */
28 __kernel_ipc_pid_t msg_lrpid; /* last receive pid */
29};
30
31/* Include the definition of msqid64_ds */
32#include <asm/msgbuf.h>
33
34/* message buffer for msgsnd and msgrcv calls */
35struct msgbuf {
36 long mtype; /* type of message */
37 char mtext[1]; /* message text */
38};
39
40/* buffer for msgctl calls IPC_INFO, MSG_INFO */
41struct msginfo {
42 int msgpool;
43 int msgmap;
44 int msgmax;
45 int msgmnb;
46 int msgmni;
47 int msgssz;
48 int msgtql;
49 unsigned short msgseg;
50};
51
52/*
53 * Scaling factor to compute msgmni:
54 * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
55 * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
56 * up to 8MB : msgmni = 16 (MSGMNI)
57 * 4 GB : msgmni = 8K
58 * more than 16 GB : msgmni = 32K (IPCMNI)
59 */
60#define MSG_MEM_SCALE 32
61
62#define MSGMNI 16 /* <= IPCMNI */ /* max # of msg queue identifiers */
63#define MSGMAX 8192 /* <= INT_MAX */ /* max size of message (bytes) */
64#define MSGMNB 16384 /* <= INT_MAX */ /* default max size of a message queue */
65
66/* unused */
67#define MSGPOOL (MSGMNI * MSGMNB / 1024) /* size in kbytes of message pool */
68#define MSGTQL MSGMNB /* number of system message headers */
69#define MSGMAP MSGMNB /* number of entries in message map */
70#define MSGSSZ 16 /* message segment size */
71#define __MSGSEG ((MSGPOOL * 1024) / MSGSSZ) /* max no. of segments */
72#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
73
74#ifdef __KERNEL__
75#include <linux/list.h>
76
77/* one msg_msg structure for each message */
78struct msg_msg {
79 struct list_head m_list;
80 long m_type;
81 int m_ts; /* message text size */
82 struct msg_msgseg* next;
83 void *security;
84 /* the actual message follows immediately */
85};
86
87/* one msq_queue structure for each present queue on the system */
88struct msg_queue {
89 struct kern_ipc_perm q_perm;
90 time_t q_stime; /* last msgsnd time */
91 time_t q_rtime; /* last msgrcv time */
92 time_t q_ctime; /* last change time */
93 unsigned long q_cbytes; /* current number of bytes on queue */
94 unsigned long q_qnum; /* number of messages in queue */
95 unsigned long q_qbytes; /* max number of bytes on queue */
96 pid_t q_lspid; /* pid of last msgsnd */
97 pid_t q_lrpid; /* last receive pid */
98
99 struct list_head q_messages;
100 struct list_head q_receivers;
101 struct list_head q_senders;
102};
103
104/* Helper routines for sys_msgsnd and sys_msgrcv */
105extern long do_msgsnd(int msqid, long mtype, void __user *mtext,
106 size_t msgsz, int msgflg);
107extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
108 size_t msgsz, long msgtyp, int msgflg);
109
110#endif /* __KERNEL__ */
111
112#endif /* _LINUX_MSG_H */