| 1 |
1634 |
jcastillo |
/*
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| 2 |
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* linux/ipc/msg.c
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| 3 |
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* Copyright (C) 1992 Krishna Balasubramanian
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| 4 |
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*
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| 5 |
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* Kerneld extensions by Bjorn Ekwall <bj0rn@blox.se> in May 1995, and May 1996
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*
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| 7 |
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* See <linux/kerneld.h> for the (optional) new kerneld protocol
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| 8 |
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*/
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#include <linux/config.h>
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| 11 |
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#include <linux/errno.h>
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| 12 |
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#include <linux/sched.h>
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| 13 |
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#include <linux/msg.h>
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| 14 |
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#include <linux/stat.h>
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| 15 |
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#include <linux/malloc.h>
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| 16 |
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#include <linux/kerneld.h>
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| 17 |
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#include <linux/interrupt.h>
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| 18 |
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| 19 |
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#include <asm/segment.h>
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| 20 |
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| 21 |
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extern int ipcperms (struct ipc_perm *ipcp, short msgflg);
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| 22 |
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| 23 |
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static void freeque (int id);
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| 24 |
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static int newque (key_t key, int msgflg);
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| 25 |
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static int findkey (key_t key);
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| 27 |
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static struct msqid_ds *msgque[MSGMNI];
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| 28 |
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static int msgbytes = 0;
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| 29 |
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static int msghdrs = 0;
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| 30 |
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static unsigned short msg_seq = 0;
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| 31 |
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static int used_queues = 0;
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| 32 |
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static int max_msqid = 0;
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| 33 |
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static struct wait_queue *msg_lock = NULL;
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| 34 |
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static int kerneld_msqid = -1;
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| 35 |
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| 36 |
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#define MAX_KERNELDS 20
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| 37 |
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static int kerneld_arr[MAX_KERNELDS];
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| 38 |
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static int n_kernelds = 0;
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| 39 |
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| 40 |
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void msg_init (void)
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{
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| 42 |
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int id;
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| 44 |
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for (id = 0; id < MSGMNI; id++)
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msgque[id] = (struct msqid_ds *) IPC_UNUSED;
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msgbytes = msghdrs = msg_seq = max_msqid = used_queues = 0;
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msg_lock = NULL;
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| 48 |
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return;
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| 49 |
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}
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| 50 |
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| 51 |
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/*
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* If the send queue is full, try to free any old messages.
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* These are most probably unwanted, since no one has picked them up...
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*/
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| 55 |
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#define MSG_FLUSH_TIME 10 /* seconds */
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| 56 |
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static void flush_msg(struct msqid_ds *msq)
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{
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| 58 |
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struct msg *nmsg;
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| 59 |
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unsigned long flags;
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| 60 |
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int flushed = 0;
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| 61 |
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| 62 |
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save_flags(flags);
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| 63 |
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cli();
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| 65 |
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/* messages were put on the queue in time order */
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| 66 |
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while ( (nmsg = msq->msg_first) &&
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| 67 |
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((CURRENT_TIME - nmsg->msg_stime) > MSG_FLUSH_TIME)) {
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| 68 |
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msgbytes -= nmsg->msg_ts;
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| 69 |
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msghdrs--;
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| 70 |
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msq->msg_cbytes -= nmsg->msg_ts;
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| 71 |
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msq->msg_qnum--;
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| 72 |
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msq->msg_first = nmsg->msg_next;
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| 73 |
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++flushed;
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| 74 |
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kfree(nmsg);
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| 75 |
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}
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| 76 |
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| 77 |
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if (msq->msg_qnum == 0)
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| 78 |
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msq->msg_first = msq->msg_last = NULL;
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| 79 |
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restore_flags(flags);
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| 80 |
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if (flushed)
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| 81 |
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printk(KERN_WARNING "flushed %d old SYSVIPC messages", flushed);
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| 82 |
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}
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| 83 |
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| 84 |
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static int real_msgsnd (int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg)
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| 85 |
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{
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| 86 |
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int id, err;
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| 87 |
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struct msqid_ds *msq;
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| 88 |
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struct ipc_perm *ipcp;
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| 89 |
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struct msg *msgh;
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| 90 |
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long mtype;
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| 91 |
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unsigned long flags;
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| 92 |
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| 93 |
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if (msgsz > MSGMAX || (long) msgsz < 0 || msqid < 0)
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| 94 |
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return -EINVAL;
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| 95 |
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if (!msgp)
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| 96 |
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return -EFAULT;
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| 97 |
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/*
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| 98 |
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* Calls from kernel level (IPC_KERNELD set)
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| 99 |
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* have the message somewhere in kernel space already!
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| 100 |
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*/
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| 101 |
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if ((msgflg & IPC_KERNELD))
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| 102 |
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mtype = msgp->mtype;
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| 103 |
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else {
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| 104 |
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err = verify_area (VERIFY_READ, msgp->mtext, msgsz);
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| 105 |
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if (err)
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| 106 |
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return err;
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| 107 |
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if ((mtype = get_user (&msgp->mtype)) < 1)
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| 108 |
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return -EINVAL;
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| 109 |
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}
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| 110 |
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id = (unsigned int) msqid % MSGMNI;
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| 111 |
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msq = msgque [id];
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| 112 |
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if (msq == IPC_UNUSED || msq == IPC_NOID)
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| 113 |
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return -EINVAL;
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| 114 |
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ipcp = &msq->msg_perm;
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| 115 |
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| 116 |
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slept:
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| 117 |
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if (msq->msg_perm.seq != (unsigned int) msqid / MSGMNI)
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| 118 |
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return -EIDRM;
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| 119 |
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/*
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| 120 |
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* Non-root kernel level processes may send to kerneld!
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| 121 |
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* i.e. no permission check if called from the kernel
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| 122 |
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* otoh we don't want user level non-root snoopers...
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| 123 |
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*/
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| 124 |
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if ((msgflg & IPC_KERNELD) == 0)
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| 125 |
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if (ipcperms(ipcp, S_IWUGO))
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| 126 |
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return -EACCES;
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| 127 |
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| 128 |
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if (msgsz + msq->msg_cbytes > msq->msg_qbytes) {
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| 129 |
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if ((kerneld_msqid != -1) && (kerneld_msqid == msqid))
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| 130 |
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flush_msg(msq); /* flush the kerneld channel only */
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if (msgsz + msq->msg_cbytes > msq->msg_qbytes) {
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| 132 |
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/* still no space in queue */
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| 133 |
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if (msgflg & IPC_NOWAIT)
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| 134 |
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return -EAGAIN;
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| 135 |
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if (current->signal & ~current->blocked)
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| 136 |
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return -EINTR;
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| 137 |
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if (intr_count) {
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| 138 |
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/* Very unlikely, but better safe than sorry */
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| 139 |
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printk(KERN_WARNING "Ouch, kerneld:msgsnd buffers full!\n");
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| 140 |
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return -EINTR;
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| 141 |
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}
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| 142 |
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interruptible_sleep_on (&msq->wwait);
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| 143 |
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goto slept;
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| 144 |
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}
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| 145 |
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}
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| 146 |
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| 147 |
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/* allocate message header and text space*/
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| 148 |
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msgh = (struct msg *) kmalloc (sizeof(*msgh) + msgsz, GFP_ATOMIC);
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| 149 |
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if (!msgh)
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| 150 |
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return -ENOMEM;
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| 151 |
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msgh->msg_spot = (char *) (msgh + 1);
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| 152 |
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| 153 |
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/*
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| 154 |
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* Calls from kernel level (IPC_KERNELD set)
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| 155 |
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* have the message somewhere in kernel space already!
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| 156 |
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*/
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| 157 |
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if (msgflg & IPC_KERNELD) {
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| 158 |
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struct kerneld_msg *kdmp = (struct kerneld_msg *)msgp;
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| 159 |
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| 160 |
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/*
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| 161 |
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* Note that the kernel supplies a pointer
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| 162 |
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* but the user-level kerneld uses a char array...
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| 163 |
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*/
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| 164 |
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memcpy(msgh->msg_spot, (char *)(&(kdmp->id)), KDHDR);
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| 165 |
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memcpy(msgh->msg_spot + KDHDR, kdmp->text, msgsz - KDHDR);
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| 166 |
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}
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| 167 |
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else
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| 168 |
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memcpy_fromfs (msgh->msg_spot, msgp->mtext, msgsz);
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| 169 |
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| 170 |
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if (msgque[id] == IPC_UNUSED || msgque[id] == IPC_NOID
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| 171 |
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|| msq->msg_perm.seq != (unsigned int) msqid / MSGMNI) {
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| 172 |
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kfree(msgh);
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| 173 |
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return -EIDRM;
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| 174 |
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}
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| 175 |
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| 176 |
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msgh->msg_next = NULL;
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| 177 |
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msgh->msg_ts = msgsz;
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| 178 |
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msgh->msg_type = mtype;
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| 179 |
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msgh->msg_stime = CURRENT_TIME;
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| 180 |
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| 181 |
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save_flags(flags);
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| 182 |
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cli();
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| 183 |
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if (!msq->msg_first)
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| 184 |
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msq->msg_first = msq->msg_last = msgh;
|
| 185 |
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else {
|
| 186 |
|
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msq->msg_last->msg_next = msgh;
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| 187 |
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msq->msg_last = msgh;
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| 188 |
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}
|
| 189 |
|
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msq->msg_cbytes += msgsz;
|
| 190 |
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msgbytes += msgsz;
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| 191 |
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msghdrs++;
|
| 192 |
|
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msq->msg_qnum++;
|
| 193 |
|
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msq->msg_lspid = current->pid;
|
| 194 |
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msq->msg_stime = CURRENT_TIME;
|
| 195 |
|
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restore_flags(flags);
|
| 196 |
|
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wake_up (&msq->rwait);
|
| 197 |
|
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return 0;
|
| 198 |
|
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}
|
| 199 |
|
|
|
| 200 |
|
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/*
|
| 201 |
|
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* Take care of missing kerneld, especially in case of multiple daemons
|
| 202 |
|
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*/
|
| 203 |
|
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#define KERNELD_TIMEOUT 1 * (HZ)
|
| 204 |
|
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#define DROP_TIMER del_timer(&kd_timer)
|
| 205 |
|
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/*#define DROP_TIMER if ((msgflg & IPC_KERNELD) && kd_timer.next && kd_timer.prev) del_timer(&kd_timer)*/
|
| 206 |
|
|
|
| 207 |
|
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static void kd_timeout(unsigned long msgid)
|
| 208 |
|
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{
|
| 209 |
|
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struct msqid_ds *msq;
|
| 210 |
|
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struct msg *tmsg;
|
| 211 |
|
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unsigned long flags;
|
| 212 |
|
|
|
| 213 |
|
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msq = msgque [ (unsigned int) kerneld_msqid % MSGMNI ];
|
| 214 |
|
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if (msq == IPC_NOID || msq == IPC_UNUSED)
|
| 215 |
|
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return;
|
| 216 |
|
|
|
| 217 |
|
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save_flags(flags);
|
| 218 |
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cli();
|
| 219 |
|
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for (tmsg = msq->msg_first; tmsg; tmsg = tmsg->msg_next)
|
| 220 |
|
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if (*(long *)(tmsg->msg_spot) == msgid)
|
| 221 |
|
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break;
|
| 222 |
|
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restore_flags(flags);
|
| 223 |
|
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if (tmsg) { /* still there! */
|
| 224 |
|
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struct kerneld_msg kmsp = { msgid, NULL_KDHDR, "" };
|
| 225 |
|
|
|
| 226 |
|
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printk(KERN_ALERT "Ouch, no kerneld for message %ld\n", msgid);
|
| 227 |
|
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kmsp.id = -ENODEV;
|
| 228 |
|
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real_msgsnd(kerneld_msqid, (struct msgbuf *)&kmsp, KDHDR,
|
| 229 |
|
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S_IRUSR | S_IWUSR | IPC_KERNELD | MSG_NOERROR);
|
| 230 |
|
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}
|
| 231 |
|
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}
|
| 232 |
|
|
|
| 233 |
|
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static int real_msgrcv (int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp, int msgflg)
|
| 234 |
|
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{
|
| 235 |
|
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struct timer_list kd_timer = { NULL, NULL, 0, 0, 0};
|
| 236 |
|
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struct msqid_ds *msq;
|
| 237 |
|
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struct ipc_perm *ipcp;
|
| 238 |
|
|
struct msg *tmsg, *leastp = NULL;
|
| 239 |
|
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struct msg *nmsg = NULL;
|
| 240 |
|
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int id, err;
|
| 241 |
|
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unsigned long flags;
|
| 242 |
|
|
|
| 243 |
|
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if (msqid < 0 || (long) msgsz < 0)
|
| 244 |
|
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return -EINVAL;
|
| 245 |
|
|
if (!msgp || !msgp->mtext)
|
| 246 |
|
|
return -EFAULT;
|
| 247 |
|
|
/*
|
| 248 |
|
|
* Calls from kernel level (IPC_KERNELD set)
|
| 249 |
|
|
* wants the message put in kernel space!
|
| 250 |
|
|
*/
|
| 251 |
|
|
if ((msgflg & IPC_KERNELD) == 0) {
|
| 252 |
|
|
err = verify_area (VERIFY_WRITE, msgp->mtext, msgsz);
|
| 253 |
|
|
if (err)
|
| 254 |
|
|
return err;
|
| 255 |
|
|
}
|
| 256 |
|
|
|
| 257 |
|
|
id = (unsigned int) msqid % MSGMNI;
|
| 258 |
|
|
msq = msgque [id];
|
| 259 |
|
|
if (msq == IPC_NOID || msq == IPC_UNUSED)
|
| 260 |
|
|
return -EINVAL;
|
| 261 |
|
|
ipcp = &msq->msg_perm;
|
| 262 |
|
|
|
| 263 |
|
|
/*
|
| 264 |
|
|
* Start timer for missing kerneld
|
| 265 |
|
|
*/
|
| 266 |
|
|
if (msgflg & IPC_KERNELD) {
|
| 267 |
|
|
kd_timer.data = (unsigned long)msgtyp;
|
| 268 |
|
|
kd_timer.expires = jiffies + KERNELD_TIMEOUT;
|
| 269 |
|
|
kd_timer.function = kd_timeout;
|
| 270 |
|
|
add_timer(&kd_timer);
|
| 271 |
|
|
}
|
| 272 |
|
|
|
| 273 |
|
|
/*
|
| 274 |
|
|
* find message of correct type.
|
| 275 |
|
|
* msgtyp = 0 => get first.
|
| 276 |
|
|
* msgtyp > 0 => get first message of matching type.
|
| 277 |
|
|
* msgtyp < 0 => get message with least type must be < abs(msgtype).
|
| 278 |
|
|
*/
|
| 279 |
|
|
while (!nmsg) {
|
| 280 |
|
|
if (msq->msg_perm.seq != (unsigned int) msqid / MSGMNI) {
|
| 281 |
|
|
DROP_TIMER;
|
| 282 |
|
|
return -EIDRM;
|
| 283 |
|
|
}
|
| 284 |
|
|
if ((msgflg & IPC_KERNELD) == 0) {
|
| 285 |
|
|
/*
|
| 286 |
|
|
* All kernel level processes may receive from kerneld!
|
| 287 |
|
|
* i.e. no permission check if called from the kernel
|
| 288 |
|
|
* otoh we don't want user level non-root snoopers...
|
| 289 |
|
|
*/
|
| 290 |
|
|
if (ipcperms (ipcp, S_IRUGO)) {
|
| 291 |
|
|
DROP_TIMER; /* Not needed, but doesn't hurt */
|
| 292 |
|
|
return -EACCES;
|
| 293 |
|
|
}
|
| 294 |
|
|
}
|
| 295 |
|
|
|
| 296 |
|
|
save_flags(flags);
|
| 297 |
|
|
cli();
|
| 298 |
|
|
if (msgtyp == 0)
|
| 299 |
|
|
nmsg = msq->msg_first;
|
| 300 |
|
|
else if (msgtyp > 0) {
|
| 301 |
|
|
if (msgflg & MSG_EXCEPT) {
|
| 302 |
|
|
for (tmsg = msq->msg_first; tmsg;
|
| 303 |
|
|
tmsg = tmsg->msg_next)
|
| 304 |
|
|
if (tmsg->msg_type != msgtyp)
|
| 305 |
|
|
break;
|
| 306 |
|
|
nmsg = tmsg;
|
| 307 |
|
|
} else {
|
| 308 |
|
|
for (tmsg = msq->msg_first; tmsg;
|
| 309 |
|
|
tmsg = tmsg->msg_next)
|
| 310 |
|
|
if (tmsg->msg_type == msgtyp)
|
| 311 |
|
|
break;
|
| 312 |
|
|
nmsg = tmsg;
|
| 313 |
|
|
}
|
| 314 |
|
|
} else {
|
| 315 |
|
|
for (leastp = tmsg = msq->msg_first; tmsg;
|
| 316 |
|
|
tmsg = tmsg->msg_next)
|
| 317 |
|
|
if (tmsg->msg_type < leastp->msg_type)
|
| 318 |
|
|
leastp = tmsg;
|
| 319 |
|
|
if (leastp && leastp->msg_type <= - msgtyp)
|
| 320 |
|
|
nmsg = leastp;
|
| 321 |
|
|
}
|
| 322 |
|
|
restore_flags(flags);
|
| 323 |
|
|
|
| 324 |
|
|
if (nmsg) { /* done finding a message */
|
| 325 |
|
|
DROP_TIMER;
|
| 326 |
|
|
if ((msgsz < nmsg->msg_ts) && !(msgflg & MSG_NOERROR)) {
|
| 327 |
|
|
return -E2BIG;
|
| 328 |
|
|
}
|
| 329 |
|
|
msgsz = (msgsz > nmsg->msg_ts)? nmsg->msg_ts : msgsz;
|
| 330 |
|
|
save_flags(flags);
|
| 331 |
|
|
cli();
|
| 332 |
|
|
if (nmsg == msq->msg_first)
|
| 333 |
|
|
msq->msg_first = nmsg->msg_next;
|
| 334 |
|
|
else {
|
| 335 |
|
|
for (tmsg = msq->msg_first; tmsg;
|
| 336 |
|
|
tmsg = tmsg->msg_next)
|
| 337 |
|
|
if (tmsg->msg_next == nmsg)
|
| 338 |
|
|
break;
|
| 339 |
|
|
tmsg->msg_next = nmsg->msg_next;
|
| 340 |
|
|
if (nmsg == msq->msg_last)
|
| 341 |
|
|
msq->msg_last = tmsg;
|
| 342 |
|
|
}
|
| 343 |
|
|
if (!(--msq->msg_qnum))
|
| 344 |
|
|
msq->msg_last = msq->msg_first = NULL;
|
| 345 |
|
|
|
| 346 |
|
|
msq->msg_rtime = CURRENT_TIME;
|
| 347 |
|
|
msq->msg_lrpid = current->pid;
|
| 348 |
|
|
msgbytes -= nmsg->msg_ts;
|
| 349 |
|
|
msghdrs--;
|
| 350 |
|
|
msq->msg_cbytes -= nmsg->msg_ts;
|
| 351 |
|
|
restore_flags(flags);
|
| 352 |
|
|
wake_up (&msq->wwait);
|
| 353 |
|
|
/*
|
| 354 |
|
|
* Calls from kernel level (IPC_KERNELD set)
|
| 355 |
|
|
* wants the message copied to kernel space!
|
| 356 |
|
|
*/
|
| 357 |
|
|
if (msgflg & IPC_KERNELD) {
|
| 358 |
|
|
struct kerneld_msg *kdmp = (struct kerneld_msg *) msgp;
|
| 359 |
|
|
|
| 360 |
|
|
memcpy((char *)(&(kdmp->id)),
|
| 361 |
|
|
nmsg->msg_spot, KDHDR);
|
| 362 |
|
|
/*
|
| 363 |
|
|
* Note that kdmp->text is a pointer
|
| 364 |
|
|
* when called from kernel space!
|
| 365 |
|
|
*/
|
| 366 |
|
|
if ((msgsz > KDHDR) && kdmp->text)
|
| 367 |
|
|
memcpy(kdmp->text,
|
| 368 |
|
|
nmsg->msg_spot + KDHDR,
|
| 369 |
|
|
msgsz - KDHDR);
|
| 370 |
|
|
}
|
| 371 |
|
|
else {
|
| 372 |
|
|
put_user (nmsg->msg_type, &msgp->mtype);
|
| 373 |
|
|
memcpy_tofs (msgp->mtext, nmsg->msg_spot, msgsz);
|
| 374 |
|
|
}
|
| 375 |
|
|
kfree(nmsg);
|
| 376 |
|
|
return msgsz;
|
| 377 |
|
|
} else { /* did not find a message */
|
| 378 |
|
|
if (msgflg & IPC_NOWAIT) {
|
| 379 |
|
|
DROP_TIMER;
|
| 380 |
|
|
return -ENOMSG;
|
| 381 |
|
|
}
|
| 382 |
|
|
if (current->signal & ~current->blocked) {
|
| 383 |
|
|
DROP_TIMER;
|
| 384 |
|
|
return -EINTR;
|
| 385 |
|
|
}
|
| 386 |
|
|
interruptible_sleep_on (&msq->rwait);
|
| 387 |
|
|
}
|
| 388 |
|
|
} /* end while */
|
| 389 |
|
|
DROP_TIMER;
|
| 390 |
|
|
return -1;
|
| 391 |
|
|
}
|
| 392 |
|
|
|
| 393 |
|
|
asmlinkage int sys_msgsnd (int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg)
|
| 394 |
|
|
{
|
| 395 |
|
|
/* IPC_KERNELD is used as a marker for kernel level calls */
|
| 396 |
|
|
return real_msgsnd(msqid, msgp, msgsz, msgflg & ~IPC_KERNELD);
|
| 397 |
|
|
}
|
| 398 |
|
|
|
| 399 |
|
|
asmlinkage int sys_msgrcv (int msqid, struct msgbuf *msgp, size_t msgsz,
|
| 400 |
|
|
long msgtyp, int msgflg)
|
| 401 |
|
|
{
|
| 402 |
|
|
/* IPC_KERNELD is used as a marker for kernel level calls */
|
| 403 |
|
|
return real_msgrcv (msqid, msgp, msgsz, msgtyp, msgflg & ~IPC_KERNELD);
|
| 404 |
|
|
}
|
| 405 |
|
|
|
| 406 |
|
|
static int findkey (key_t key)
|
| 407 |
|
|
{
|
| 408 |
|
|
int id;
|
| 409 |
|
|
struct msqid_ds *msq;
|
| 410 |
|
|
|
| 411 |
|
|
for (id = 0; id <= max_msqid; id++) {
|
| 412 |
|
|
while ((msq = msgque[id]) == IPC_NOID)
|
| 413 |
|
|
interruptible_sleep_on (&msg_lock);
|
| 414 |
|
|
if (msq == IPC_UNUSED)
|
| 415 |
|
|
continue;
|
| 416 |
|
|
if (key == msq->msg_perm.key)
|
| 417 |
|
|
return id;
|
| 418 |
|
|
}
|
| 419 |
|
|
return -1;
|
| 420 |
|
|
}
|
| 421 |
|
|
|
| 422 |
|
|
static int newque (key_t key, int msgflg)
|
| 423 |
|
|
{
|
| 424 |
|
|
int id;
|
| 425 |
|
|
struct msqid_ds *msq;
|
| 426 |
|
|
struct ipc_perm *ipcp;
|
| 427 |
|
|
|
| 428 |
|
|
for (id = 0; id < MSGMNI; id++)
|
| 429 |
|
|
if (msgque[id] == IPC_UNUSED) {
|
| 430 |
|
|
msgque[id] = (struct msqid_ds *) IPC_NOID;
|
| 431 |
|
|
goto found;
|
| 432 |
|
|
}
|
| 433 |
|
|
return -ENOSPC;
|
| 434 |
|
|
|
| 435 |
|
|
found:
|
| 436 |
|
|
msq = (struct msqid_ds *) kmalloc (sizeof (*msq), GFP_KERNEL);
|
| 437 |
|
|
if (!msq) {
|
| 438 |
|
|
msgque[id] = (struct msqid_ds *) IPC_UNUSED;
|
| 439 |
|
|
wake_up (&msg_lock);
|
| 440 |
|
|
return -ENOMEM;
|
| 441 |
|
|
}
|
| 442 |
|
|
ipcp = &msq->msg_perm;
|
| 443 |
|
|
ipcp->mode = (msgflg & S_IRWXUGO);
|
| 444 |
|
|
ipcp->key = key;
|
| 445 |
|
|
ipcp->cuid = ipcp->uid = current->euid;
|
| 446 |
|
|
ipcp->gid = ipcp->cgid = current->egid;
|
| 447 |
|
|
msq->msg_perm.seq = msg_seq;
|
| 448 |
|
|
msq->msg_first = msq->msg_last = NULL;
|
| 449 |
|
|
msq->rwait = msq->wwait = NULL;
|
| 450 |
|
|
msq->msg_cbytes = msq->msg_qnum = 0;
|
| 451 |
|
|
msq->msg_lspid = msq->msg_lrpid = 0;
|
| 452 |
|
|
msq->msg_stime = msq->msg_rtime = 0;
|
| 453 |
|
|
msq->msg_qbytes = MSGMNB;
|
| 454 |
|
|
msq->msg_ctime = CURRENT_TIME;
|
| 455 |
|
|
if (id > max_msqid)
|
| 456 |
|
|
max_msqid = id;
|
| 457 |
|
|
msgque[id] = msq;
|
| 458 |
|
|
used_queues++;
|
| 459 |
|
|
wake_up (&msg_lock);
|
| 460 |
|
|
return (unsigned int) msq->msg_perm.seq * MSGMNI + id;
|
| 461 |
|
|
}
|
| 462 |
|
|
|
| 463 |
|
|
asmlinkage int sys_msgget (key_t key, int msgflg)
|
| 464 |
|
|
{
|
| 465 |
|
|
int id;
|
| 466 |
|
|
struct msqid_ds *msq;
|
| 467 |
|
|
|
| 468 |
|
|
/*
|
| 469 |
|
|
* If the IPC_KERNELD flag is set, the key is forced to IPC_PRIVATE,
|
| 470 |
|
|
* and a designated kerneld message queue is created/referred to
|
| 471 |
|
|
*/
|
| 472 |
|
|
if ((msgflg & IPC_KERNELD)) {
|
| 473 |
|
|
int i;
|
| 474 |
|
|
if (!suser())
|
| 475 |
|
|
return -EPERM;
|
| 476 |
|
|
#ifdef NEW_KERNELD_PROTOCOL
|
| 477 |
|
|
if ((msgflg & IPC_KERNELD) == OLDIPC_KERNELD) {
|
| 478 |
|
|
printk(KERN_ALERT "Please recompile your kerneld daemons!\n");
|
| 479 |
|
|
return -EPERM;
|
| 480 |
|
|
}
|
| 481 |
|
|
#endif
|
| 482 |
|
|
if ((kerneld_msqid == -1) && (kerneld_msqid =
|
| 483 |
|
|
newque(IPC_PRIVATE, msgflg & S_IRWXU)) < 0)
|
| 484 |
|
|
return -ENOSPC;
|
| 485 |
|
|
for (i = 0; i < MAX_KERNELDS; ++i) {
|
| 486 |
|
|
if (kerneld_arr[i] == 0) {
|
| 487 |
|
|
kerneld_arr[i] = current->pid;
|
| 488 |
|
|
++n_kernelds;
|
| 489 |
|
|
return kerneld_msqid;
|
| 490 |
|
|
}
|
| 491 |
|
|
}
|
| 492 |
|
|
return -ENOSPC;
|
| 493 |
|
|
}
|
| 494 |
|
|
/* else it is a "normal" request */
|
| 495 |
|
|
if (key == IPC_PRIVATE)
|
| 496 |
|
|
return newque(key, msgflg);
|
| 497 |
|
|
if ((id = findkey (key)) == -1) { /* key not used */
|
| 498 |
|
|
if (!(msgflg & IPC_CREAT))
|
| 499 |
|
|
return -ENOENT;
|
| 500 |
|
|
return newque(key, msgflg);
|
| 501 |
|
|
}
|
| 502 |
|
|
if (msgflg & IPC_CREAT && msgflg & IPC_EXCL)
|
| 503 |
|
|
return -EEXIST;
|
| 504 |
|
|
msq = msgque[id];
|
| 505 |
|
|
if (msq == IPC_UNUSED || msq == IPC_NOID)
|
| 506 |
|
|
return -EIDRM;
|
| 507 |
|
|
if (ipcperms(&msq->msg_perm, msgflg))
|
| 508 |
|
|
return -EACCES;
|
| 509 |
|
|
return (unsigned int) msq->msg_perm.seq * MSGMNI + id;
|
| 510 |
|
|
}
|
| 511 |
|
|
|
| 512 |
|
|
static void freeque (int id)
|
| 513 |
|
|
{
|
| 514 |
|
|
struct msqid_ds *msq = msgque[id];
|
| 515 |
|
|
struct msg *msgp, *msgh;
|
| 516 |
|
|
|
| 517 |
|
|
msq->msg_perm.seq++;
|
| 518 |
|
|
msg_seq = (msg_seq+1) % ((unsigned)(1<<31)/MSGMNI); /* increment, but avoid overflow */
|
| 519 |
|
|
msgbytes -= msq->msg_cbytes;
|
| 520 |
|
|
if (id == max_msqid)
|
| 521 |
|
|
while (max_msqid && (msgque[--max_msqid] == IPC_UNUSED));
|
| 522 |
|
|
msgque[id] = (struct msqid_ds *) IPC_UNUSED;
|
| 523 |
|
|
used_queues--;
|
| 524 |
|
|
while (waitqueue_active(&msq->rwait) || waitqueue_active(&msq->wwait)) {
|
| 525 |
|
|
wake_up (&msq->rwait);
|
| 526 |
|
|
wake_up (&msq->wwait);
|
| 527 |
|
|
schedule();
|
| 528 |
|
|
}
|
| 529 |
|
|
for (msgp = msq->msg_first; msgp; msgp = msgh ) {
|
| 530 |
|
|
msgh = msgp->msg_next;
|
| 531 |
|
|
msghdrs--;
|
| 532 |
|
|
kfree(msgp);
|
| 533 |
|
|
}
|
| 534 |
|
|
kfree(msq);
|
| 535 |
|
|
}
|
| 536 |
|
|
|
| 537 |
|
|
asmlinkage int sys_msgctl (int msqid, int cmd, struct msqid_ds *buf)
|
| 538 |
|
|
{
|
| 539 |
|
|
int id, err;
|
| 540 |
|
|
struct msqid_ds *msq;
|
| 541 |
|
|
struct msqid_ds tbuf;
|
| 542 |
|
|
struct ipc_perm *ipcp;
|
| 543 |
|
|
|
| 544 |
|
|
if (msqid < 0 || cmd < 0)
|
| 545 |
|
|
return -EINVAL;
|
| 546 |
|
|
switch (cmd) {
|
| 547 |
|
|
case IPC_INFO:
|
| 548 |
|
|
case MSG_INFO:
|
| 549 |
|
|
if (!buf)
|
| 550 |
|
|
return -EFAULT;
|
| 551 |
|
|
{
|
| 552 |
|
|
struct msginfo msginfo;
|
| 553 |
|
|
msginfo.msgmni = MSGMNI;
|
| 554 |
|
|
msginfo.msgmax = MSGMAX;
|
| 555 |
|
|
msginfo.msgmnb = MSGMNB;
|
| 556 |
|
|
msginfo.msgmap = MSGMAP;
|
| 557 |
|
|
msginfo.msgpool = MSGPOOL;
|
| 558 |
|
|
msginfo.msgtql = MSGTQL;
|
| 559 |
|
|
msginfo.msgssz = MSGSSZ;
|
| 560 |
|
|
msginfo.msgseg = MSGSEG;
|
| 561 |
|
|
if (cmd == MSG_INFO) {
|
| 562 |
|
|
msginfo.msgpool = used_queues;
|
| 563 |
|
|
msginfo.msgmap = msghdrs;
|
| 564 |
|
|
msginfo.msgtql = msgbytes;
|
| 565 |
|
|
}
|
| 566 |
|
|
err = verify_area (VERIFY_WRITE, buf, sizeof (struct msginfo));
|
| 567 |
|
|
if (err)
|
| 568 |
|
|
return err;
|
| 569 |
|
|
memcpy_tofs (buf, &msginfo, sizeof(struct msginfo));
|
| 570 |
|
|
return max_msqid;
|
| 571 |
|
|
}
|
| 572 |
|
|
case MSG_STAT:
|
| 573 |
|
|
if (!buf)
|
| 574 |
|
|
return -EFAULT;
|
| 575 |
|
|
err = verify_area (VERIFY_WRITE, buf, sizeof (*buf));
|
| 576 |
|
|
if (err)
|
| 577 |
|
|
return err;
|
| 578 |
|
|
if (msqid > max_msqid)
|
| 579 |
|
|
return -EINVAL;
|
| 580 |
|
|
msq = msgque[msqid];
|
| 581 |
|
|
if (msq == IPC_UNUSED || msq == IPC_NOID)
|
| 582 |
|
|
return -EINVAL;
|
| 583 |
|
|
if (ipcperms (&msq->msg_perm, S_IRUGO))
|
| 584 |
|
|
return -EACCES;
|
| 585 |
|
|
id = (unsigned int) msq->msg_perm.seq * MSGMNI + msqid;
|
| 586 |
|
|
tbuf.msg_perm = msq->msg_perm;
|
| 587 |
|
|
tbuf.msg_stime = msq->msg_stime;
|
| 588 |
|
|
tbuf.msg_rtime = msq->msg_rtime;
|
| 589 |
|
|
tbuf.msg_ctime = msq->msg_ctime;
|
| 590 |
|
|
tbuf.msg_cbytes = msq->msg_cbytes;
|
| 591 |
|
|
tbuf.msg_qnum = msq->msg_qnum;
|
| 592 |
|
|
tbuf.msg_qbytes = msq->msg_qbytes;
|
| 593 |
|
|
tbuf.msg_lspid = msq->msg_lspid;
|
| 594 |
|
|
tbuf.msg_lrpid = msq->msg_lrpid;
|
| 595 |
|
|
memcpy_tofs (buf, &tbuf, sizeof(*buf));
|
| 596 |
|
|
return id;
|
| 597 |
|
|
case IPC_SET:
|
| 598 |
|
|
if (!buf)
|
| 599 |
|
|
return -EFAULT;
|
| 600 |
|
|
err = verify_area (VERIFY_READ, buf, sizeof (*buf));
|
| 601 |
|
|
if (err)
|
| 602 |
|
|
return err;
|
| 603 |
|
|
memcpy_fromfs (&tbuf, buf, sizeof (*buf));
|
| 604 |
|
|
break;
|
| 605 |
|
|
case IPC_STAT:
|
| 606 |
|
|
if (!buf)
|
| 607 |
|
|
return -EFAULT;
|
| 608 |
|
|
err = verify_area (VERIFY_WRITE, buf, sizeof(*buf));
|
| 609 |
|
|
if (err)
|
| 610 |
|
|
return err;
|
| 611 |
|
|
break;
|
| 612 |
|
|
}
|
| 613 |
|
|
|
| 614 |
|
|
id = (unsigned int) msqid % MSGMNI;
|
| 615 |
|
|
msq = msgque [id];
|
| 616 |
|
|
if (msq == IPC_UNUSED || msq == IPC_NOID)
|
| 617 |
|
|
return -EINVAL;
|
| 618 |
|
|
if (msq->msg_perm.seq != (unsigned int) msqid / MSGMNI)
|
| 619 |
|
|
return -EIDRM;
|
| 620 |
|
|
ipcp = &msq->msg_perm;
|
| 621 |
|
|
|
| 622 |
|
|
switch (cmd) {
|
| 623 |
|
|
case IPC_STAT:
|
| 624 |
|
|
if (ipcperms (ipcp, S_IRUGO))
|
| 625 |
|
|
return -EACCES;
|
| 626 |
|
|
tbuf.msg_perm = msq->msg_perm;
|
| 627 |
|
|
tbuf.msg_stime = msq->msg_stime;
|
| 628 |
|
|
tbuf.msg_rtime = msq->msg_rtime;
|
| 629 |
|
|
tbuf.msg_ctime = msq->msg_ctime;
|
| 630 |
|
|
tbuf.msg_cbytes = msq->msg_cbytes;
|
| 631 |
|
|
tbuf.msg_qnum = msq->msg_qnum;
|
| 632 |
|
|
tbuf.msg_qbytes = msq->msg_qbytes;
|
| 633 |
|
|
tbuf.msg_lspid = msq->msg_lspid;
|
| 634 |
|
|
tbuf.msg_lrpid = msq->msg_lrpid;
|
| 635 |
|
|
memcpy_tofs (buf, &tbuf, sizeof (*buf));
|
| 636 |
|
|
return 0;
|
| 637 |
|
|
case IPC_SET:
|
| 638 |
|
|
if (!suser() && current->euid != ipcp->cuid &&
|
| 639 |
|
|
current->euid != ipcp->uid)
|
| 640 |
|
|
return -EPERM;
|
| 641 |
|
|
if (tbuf.msg_qbytes > MSGMNB && !suser())
|
| 642 |
|
|
return -EPERM;
|
| 643 |
|
|
msq->msg_qbytes = tbuf.msg_qbytes;
|
| 644 |
|
|
ipcp->uid = tbuf.msg_perm.uid;
|
| 645 |
|
|
ipcp->gid = tbuf.msg_perm.gid;
|
| 646 |
|
|
ipcp->mode = (ipcp->mode & ~S_IRWXUGO) |
|
| 647 |
|
|
(S_IRWXUGO & tbuf.msg_perm.mode);
|
| 648 |
|
|
msq->msg_ctime = CURRENT_TIME;
|
| 649 |
|
|
return 0;
|
| 650 |
|
|
case IPC_RMID:
|
| 651 |
|
|
if (!suser() && current->euid != ipcp->cuid &&
|
| 652 |
|
|
current->euid != ipcp->uid)
|
| 653 |
|
|
return -EPERM;
|
| 654 |
|
|
/*
|
| 655 |
|
|
* There is only one kerneld message queue,
|
| 656 |
|
|
* mark it as non-existent
|
| 657 |
|
|
*/
|
| 658 |
|
|
if ((kerneld_msqid >= 0) && (msqid == kerneld_msqid))
|
| 659 |
|
|
kerneld_msqid = -1;
|
| 660 |
|
|
freeque (id);
|
| 661 |
|
|
return 0;
|
| 662 |
|
|
default:
|
| 663 |
|
|
return -EINVAL;
|
| 664 |
|
|
}
|
| 665 |
|
|
}
|
| 666 |
|
|
|
| 667 |
|
|
/*
|
| 668 |
|
|
* We do perhaps need a "flush" for waiting processes,
|
| 669 |
|
|
* so that if they are terminated, a call from do_exit
|
| 670 |
|
|
* will minimize the possibility of orphaned received
|
| 671 |
|
|
* messages in the queue. For now we just make sure
|
| 672 |
|
|
* that the queue is shut down whenever all kernelds have died.
|
| 673 |
|
|
*/
|
| 674 |
|
|
void kerneld_exit(void)
|
| 675 |
|
|
{
|
| 676 |
|
|
int i;
|
| 677 |
|
|
|
| 678 |
|
|
if (kerneld_msqid == -1)
|
| 679 |
|
|
return;
|
| 680 |
|
|
for (i = 0; i < MAX_KERNELDS; ++i) {
|
| 681 |
|
|
if (kerneld_arr[i] == current->pid) {
|
| 682 |
|
|
kerneld_arr[i] = 0;
|
| 683 |
|
|
--n_kernelds;
|
| 684 |
|
|
if (n_kernelds == 0)
|
| 685 |
|
|
sys_msgctl(kerneld_msqid, IPC_RMID, NULL);
|
| 686 |
|
|
break;
|
| 687 |
|
|
}
|
| 688 |
|
|
}
|
| 689 |
|
|
}
|
| 690 |
|
|
|
| 691 |
|
|
/*
|
| 692 |
|
|
* Kerneld internal message format/syntax:
|
| 693 |
|
|
*
|
| 694 |
|
|
* The message type from the kernel to kerneld is used to specify _what_
|
| 695 |
|
|
* function we want kerneld to perform.
|
| 696 |
|
|
*
|
| 697 |
|
|
* The "normal" message area is divided into a header, followed by a char array.
|
| 698 |
|
|
* The header is used to hold the sequence number of the request, which will
|
| 699 |
|
|
* be used as the return message type from kerneld back to the kernel.
|
| 700 |
|
|
* In the return message, the header will be used to store the exit status
|
| 701 |
|
|
* of the kerneld "job", or task.
|
| 702 |
|
|
* The character array is used to pass parameters to kerneld and (optional)
|
| 703 |
|
|
* return information from kerneld back to the kernel.
|
| 704 |
|
|
* It is the responsibility of kerneld and the kernel level caller
|
| 705 |
|
|
* to set usable sizes on the parameter/return value array, since
|
| 706 |
|
|
* that information is _not_ included in the message format
|
| 707 |
|
|
*/
|
| 708 |
|
|
|
| 709 |
|
|
/*
|
| 710 |
|
|
* The basic kernel level entry point to kerneld.
|
| 711 |
|
|
* msgtype should correspond to a task type for (a) kerneld
|
| 712 |
|
|
* ret_size is the size of the (optional) return _value,
|
| 713 |
|
|
* OR-ed with KERNELD_WAIT if we want an answer
|
| 714 |
|
|
* msgsize is the size (in bytes) of the message, not including
|
| 715 |
|
|
* the header that is always sent first in a kerneld message
|
| 716 |
|
|
* text is the parameter for the kerneld specific task
|
| 717 |
|
|
* ret_val is NULL or the kernel address where an expected answer
|
| 718 |
|
|
* from kerneld should be placed.
|
| 719 |
|
|
*
|
| 720 |
|
|
* See <linux/kerneld.h> for usage (inline convenience functions)
|
| 721 |
|
|
*
|
| 722 |
|
|
*/
|
| 723 |
|
|
int kerneld_send(int msgtype, int ret_size, int msgsz,
|
| 724 |
|
|
const char *text, const char *ret_val)
|
| 725 |
|
|
{
|
| 726 |
|
|
int status = -ENOSYS;
|
| 727 |
|
|
#ifdef CONFIG_KERNELD
|
| 728 |
|
|
static int id = KERNELD_MINSEQ;
|
| 729 |
|
|
struct kerneld_msg kmsp = { msgtype, NULL_KDHDR, (char *)text };
|
| 730 |
|
|
int msgflg = S_IRUSR | S_IWUSR | IPC_KERNELD | MSG_NOERROR;
|
| 731 |
|
|
unsigned long flags;
|
| 732 |
|
|
|
| 733 |
|
|
if (kerneld_msqid == -1)
|
| 734 |
|
|
return -ENODEV;
|
| 735 |
|
|
|
| 736 |
|
|
/* Do not wait for an answer at interrupt-time! */
|
| 737 |
|
|
if (intr_count)
|
| 738 |
|
|
ret_size &= ~KERNELD_WAIT;
|
| 739 |
|
|
#ifdef NEW_KERNELD_PROTOCOL
|
| 740 |
|
|
else
|
| 741 |
|
|
kmsp.pid = current->pid;
|
| 742 |
|
|
#endif
|
| 743 |
|
|
|
| 744 |
|
|
msgsz += KDHDR;
|
| 745 |
|
|
if (ret_size & KERNELD_WAIT) {
|
| 746 |
|
|
save_flags(flags);
|
| 747 |
|
|
cli();
|
| 748 |
|
|
if (++id <= 0) /* overflow */
|
| 749 |
|
|
id = KERNELD_MINSEQ;
|
| 750 |
|
|
kmsp.id = id;
|
| 751 |
|
|
restore_flags(flags);
|
| 752 |
|
|
}
|
| 753 |
|
|
|
| 754 |
|
|
status = real_msgsnd(kerneld_msqid, (struct msgbuf *)&kmsp, msgsz, msgflg);
|
| 755 |
|
|
if ((status >= 0) && (ret_size & KERNELD_WAIT)) {
|
| 756 |
|
|
ret_size &= ~KERNELD_WAIT;
|
| 757 |
|
|
kmsp.text = (char *)ret_val;
|
| 758 |
|
|
status = real_msgrcv(kerneld_msqid, (struct msgbuf *)&kmsp,
|
| 759 |
|
|
KDHDR + ((ret_val)?ret_size:0),
|
| 760 |
|
|
kmsp.id, msgflg);
|
| 761 |
|
|
if (status > 0) /* a valid answer contains at least a long */
|
| 762 |
|
|
status = kmsp.id;
|
| 763 |
|
|
}
|
| 764 |
|
|
|
| 765 |
|
|
#endif /* CONFIG_KERNELD */
|
| 766 |
|
|
return status;
|
| 767 |
|
|
}
|
