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      1 #ifndef _UAPI_LINUX_MSG_H
      2 #define _UAPI_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 #define MSG_COPY        040000  /* copy (not remove) all queue messages */
     14 
     15 /* Obsolete, used only for backwards compatibility and libc5 compiles */
     16 struct msqid_ds {
     17 	struct ipc_perm msg_perm;
     18 	struct msg *msg_first;		/* first message on queue,unused  */
     19 	struct msg *msg_last;		/* last message in queue,unused */
     20 	__kernel_time_t msg_stime;	/* last msgsnd time */
     21 	__kernel_time_t msg_rtime;	/* last msgrcv time */
     22 	__kernel_time_t msg_ctime;	/* last change time */
     23 	unsigned long  msg_lcbytes;	/* Reuse junk fields for 32 bit */
     24 	unsigned long  msg_lqbytes;	/* ditto */
     25 	unsigned short msg_cbytes;	/* current number of bytes on queue */
     26 	unsigned short msg_qnum;	/* number of messages in queue */
     27 	unsigned short msg_qbytes;	/* max number of bytes on queue */
     28 	__kernel_ipc_pid_t msg_lspid;	/* pid of last msgsnd */
     29 	__kernel_ipc_pid_t msg_lrpid;	/* last receive pid */
     30 };
     31 
     32 /* Include the definition of msqid64_ds */
     33 #include <asm/msgbuf.h>
     34 
     35 /* message buffer for msgsnd and msgrcv calls */
     36 struct msgbuf {
     37 	__kernel_long_t mtype;          /* type of message */
     38 	char mtext[1];                  /* message text */
     39 };
     40 
     41 /* buffer for msgctl calls IPC_INFO, MSG_INFO */
     42 struct msginfo {
     43 	int msgpool;
     44 	int msgmap;
     45 	int msgmax;
     46 	int msgmnb;
     47 	int msgmni;
     48 	int msgssz;
     49 	int msgtql;
     50 	unsigned short  msgseg;
     51 };
     52 
     53 /*
     54  * Scaling factor to compute msgmni:
     55  * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
     56  * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
     57  * up to 8MB       : msgmni = 16 (MSGMNI)
     58  * 4 GB            : msgmni = 8K
     59  * more than 16 GB : msgmni = 32K (IPCMNI)
     60  */
     61 #define MSG_MEM_SCALE 32
     62 
     63 #define MSGMNI    16   /* <= IPCMNI */     /* max # of msg queue identifiers */
     64 #define MSGMAX  8192   /* <= INT_MAX */   /* max size of message (bytes) */
     65 #define MSGMNB 16384   /* <= INT_MAX */   /* default max size of a message queue */
     66 
     67 /* unused */
     68 #define MSGPOOL (MSGMNI * MSGMNB / 1024) /* size in kbytes of message pool */
     69 #define MSGTQL  MSGMNB            /* number of system message headers */
     70 #define MSGMAP  MSGMNB            /* number of entries in message map */
     71 #define MSGSSZ  16                /* message segment size */
     72 #define __MSGSEG ((MSGPOOL * 1024) / MSGSSZ) /* max no. of segments */
     73 #define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
     74 
     75 
     76 #endif /* _UAPI_LINUX_MSG_H */
     77