asmlinkage long sys_msgget (key_t key, int msgflg)
{
int id, ret = -EPERM;
struct msg_queue *msq;
down(&msg_ids.sem);
if (key == IPC_PRIVATE)
ret = newque(key, msgflg);
else if ((id = ipc_findkey(&msg_ids, key)) == -1) { /* key not used */
if (!(msgflg & IPC_CREAT))
ret = -ENOENT;
else
ret = newque(key, msgflg);
} else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) {
ret = -EEXIST;
} else {
msq = msg_lock(id);
if(msq==NULL)
BUG();
if (ipcperms(&msq->q_perm, msgflg))
ret = -EACCES;
else
ret = msg_buildid(id, msq->q_perm.seq);
msg_unlock(id);
}
up(&msg_ids.sem);
TRACE_IPC(TRACE_EV_IPC_MSG_CREATE, ret, msgflg);
return ret;
}
static int newque (key_t key, int msgflg)
{
int id;
struct msg_queue *msq;
msq = (struct msg_queue *) kmalloc (sizeof (*msq), GFP_KERNEL);
if (!msq)
return -ENOMEM;
id = ipc_addid(&msg_ids, &msq->q_perm, msg_ctlmni);
if(id == -1) {
kfree(msq);
return -ENOSPC;
}
msq->q_perm.mode = (msgflg & S_IRWXUGO);
msq->q_perm.key = key;
msq->q_stime = msq->q_rtime = 0;
msq->q_ctime = CURRENT_TIME;
msq->q_cbytes = msq->q_qnum = 0;
msq->q_qbytes = msg_ctlmnb;
msq->q_lspid = msq->q_lrpid = 0;
INIT_LIST_HEAD(&msq->q_messages);
INIT_LIST_HEAD(&msq->q_receivers);
INIT_LIST_HEAD(&msq->q_senders);
msg_unlock(id);
return msg_buildid(id,msq->q_perm.seq);
}
static int sysvipc_msg_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
{
off_t pos = 0;
off_t begin = 0;
int i, len = 0;
down(&msg_ids.sem);
len += sprintf(buffer, " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n");
for(i = 0; i <= msg_ids.max_id; i++) {
struct msg_queue * msq;
msq = msg_lock(i);
if(msq != NULL) {
len += sprintf(buffer + len, "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
msq->q_perm.key,
msg_buildid(i,msq->q_perm.seq),
msq->q_perm.mode,
msq->q_cbytes,
msq->q_qnum,
msq->q_lspid,
msq->q_lrpid,
msq->q_perm.uid,
msq->q_perm.gid,
msq->q_perm.cuid,
msq->q_perm.cgid,
msq->q_stime,
msq->q_rtime,
msq->q_ctime);
msg_unlock(i);
pos += len;
if(pos < offset) {
len = 0;
begin = pos;
}
if(pos > offset + length)
goto done;
}
}
*eof = 1;
done:
up(&msg_ids.sem);
*start = buffer + (offset - begin);
len -= (offset - begin);
if(len > length)
len = length;
if(len < 0)
len = 0;
return len;
}
static int newque (key_t key, int msgflg)
{
int id;
int retval;
struct msg_queue *msq;
msq = ipc_rcu_alloc(sizeof(*msq));
if (!msq)
return -ENOMEM;
msq->q_perm.mode = (msgflg & S_IRWXUGO);
msq->q_perm.key = key;
msq->q_perm.security = NULL;
retval = security_msg_queue_alloc(msq);
if (retval) {
ipc_rcu_free(msq, sizeof(*msq));
return retval;
}
id = ipc_addid(&msg_ids, &msq->q_perm, msg_ctlmni);
if(id == -1) {
security_msg_queue_free(msq);
ipc_rcu_free(msq, sizeof(*msq));
return -ENOSPC;
}
msq->q_stime = msq->q_rtime = 0;
msq->q_ctime = get_seconds();
msq->q_cbytes = msq->q_qnum = 0;
msq->q_qbytes = msg_ctlmnb;
msq->q_lspid = msq->q_lrpid = 0;
INIT_LIST_HEAD(&msq->q_messages);
INIT_LIST_HEAD(&msq->q_receivers);
INIT_LIST_HEAD(&msq->q_senders);
msg_unlock(msq);
return msg_buildid(id,msq->q_perm.seq);
}
asmlinkage long sys_msgget(key_t key, int msgflg)
{
struct msg_queue *msq;
int id, ret = -EPERM;
struct ipc_namespace *ns;
ns = current->nsproxy->ipc_ns;
mutex_lock(&msg_ids(ns).mutex);
if (key == IPC_PRIVATE)
ret = newque(ns, key, msgflg);
else if ((id = ipc_findkey(&msg_ids(ns), key)) == -1) { /* key not used */
if (!(msgflg & IPC_CREAT))
ret = -ENOENT;
else
ret = newque(ns, key, msgflg);
} else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) {
ret = -EEXIST;
} else {
msq = msg_lock(ns, id);
BUG_ON(msq == NULL);
if (ipcperms(&msq->q_perm, msgflg))
ret = -EACCES;
else {
int qid = msg_buildid(ns, id, msq->q_perm.seq);
ret = security_msg_queue_associate(msq, msgflg);
if (!ret)
ret = qid;
}
msg_unlock(msq);
}
mutex_unlock(&msg_ids(ns).mutex);
return ret;
}
asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds *buf)
{
int err, version;
struct msg_queue *msq;
struct msq_setbuf setbuf;
struct kern_ipc_perm *ipcp;
if (msqid < 0 || cmd < 0)
return -EINVAL;
version = ipc_parse_version(&cmd);
switch (cmd) {
case IPC_INFO:
case MSG_INFO:
{
struct msginfo msginfo;
int max_id;
if (!buf)
return -EFAULT;
/* We must not return kernel stack data.
* due to padding, it's not enough
* to set all member fields.
*/
memset(&msginfo,0,sizeof(msginfo));
msginfo.msgmni = msg_ctlmni;
msginfo.msgmax = msg_ctlmax;
msginfo.msgmnb = msg_ctlmnb;
msginfo.msgssz = MSGSSZ;
msginfo.msgseg = MSGSEG;
down(&msg_ids.sem);
if (cmd == MSG_INFO) {
msginfo.msgpool = msg_ids.in_use;
msginfo.msgmap = atomic_read(&msg_hdrs);
msginfo.msgtql = atomic_read(&msg_bytes);
} else {
msginfo.msgmap = MSGMAP;
msginfo.msgpool = MSGPOOL;
msginfo.msgtql = MSGTQL;
}
max_id = msg_ids.max_id;
up(&msg_ids.sem);
if (copy_to_user (buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0: max_id;
}
case MSG_STAT:
case IPC_STAT:
{
struct msqid64_ds tbuf;
int success_return;
if (!buf)
return -EFAULT;
if(cmd == MSG_STAT && msqid >= msg_ids.size)
return -EINVAL;
memset(&tbuf,0,sizeof(tbuf));
msq = msg_lock(msqid);
if (msq == NULL)
return -EINVAL;
if(cmd == MSG_STAT) {
success_return = msg_buildid(msqid, msq->q_perm.seq);
} else {
err = -EIDRM;
if (msg_checkid(msq,msqid))
goto out_unlock;
success_return = 0;
}
err = -EACCES;
if (ipcperms (&msq->q_perm, S_IRUGO))
goto out_unlock;
kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
tbuf.msg_stime = msq->q_stime;
tbuf.msg_rtime = msq->q_rtime;
tbuf.msg_ctime = msq->q_ctime;
tbuf.msg_cbytes = msq->q_cbytes;
tbuf.msg_qnum = msq->q_qnum;
tbuf.msg_qbytes = msq->q_qbytes;
tbuf.msg_lspid = msq->q_lspid;
tbuf.msg_lrpid = msq->q_lrpid;
msg_unlock(msqid);
if (copy_msqid_to_user(buf, &tbuf, version))
return -EFAULT;
return success_return;
}
case IPC_SET:
if (!buf)
return -EFAULT;
if (copy_msqid_from_user (&setbuf, buf, version))
return -EFAULT;
break;
case IPC_RMID:
break;
default:
return -EINVAL;
}
down(&msg_ids.sem);
msq = msg_lock(msqid);
err=-EINVAL;
if (msq == NULL)
goto out_up;
err = -EIDRM;
if (msg_checkid(msq,msqid))
goto out_unlock_up;
ipcp = &msq->q_perm;
err = -EPERM;
if (current->euid != ipcp->cuid &&
current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN))
/* We _could_ check for CAP_CHOWN above, but we don't */
goto out_unlock_up;
switch (cmd) {
case IPC_SET:
{
if (setbuf.qbytes > msg_ctlmnb && !capable(CAP_SYS_RESOURCE))
goto out_unlock_up;
msq->q_qbytes = setbuf.qbytes;
ipcp->uid = setbuf.uid;
ipcp->gid = setbuf.gid;
ipcp->mode = (ipcp->mode & ~S_IRWXUGO) |
(S_IRWXUGO & setbuf.mode);
msq->q_ctime = CURRENT_TIME;
/* sleeping receivers might be excluded by
* stricter permissions.
*/
expunge_all(msq,-EAGAIN);
/* sleeping senders might be able to send
* due to a larger queue size.
*/
ss_wakeup(&msq->q_senders,0);
msg_unlock(msqid);
break;
}
case IPC_RMID:
freeque (msqid);
break;
}
err = 0;
out_up:
up(&msg_ids.sem);
return err;
out_unlock_up:
msg_unlock(msqid);
goto out_up;
out_unlock:
msg_unlock(msqid);
return err;
}
