long do_msgsnd(int msqid, long mtype, void __user *mtext,
size_t msgsz, int msgflg)
{
struct msg_queue *msq;
struct msg_msg *msg;
int err;
struct ipc_namespace *ns;
ns = current->nsproxy->ipc_ns;
if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
return -EINVAL;
if (mtype < 1)
return -EINVAL;
msg = load_msg(mtext, msgsz);
if (IS_ERR(msg))
return PTR_ERR(msg);
msg->m_type = mtype;
msg->m_ts = msgsz;
msq = msg_lock_check(ns, msqid);
if (IS_ERR(msq)) {
err = PTR_ERR(msq);
goto out_free;
}
for (;;) {
struct msg_sender s;
err = -EACCES;
if (ipcperms(&msq->q_perm, S_IWUGO))
goto out_unlock_free;
err = security_msg_queue_msgsnd(msq, msg, msgflg);
if (err)
goto out_unlock_free;
if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
1 + msq->q_qnum <= msq->q_qbytes) {
break;
}
/* queue full, wait: */
if (msgflg & IPC_NOWAIT) {
err = -EAGAIN;
goto out_unlock_free;
}
ss_add(msq, &s);
ipc_rcu_getref(msq);
msg_unlock(msq);
schedule();
ipc_lock_by_ptr(&msq->q_perm);
ipc_rcu_putref(msq);
if (msq->q_perm.deleted) {
err = -EIDRM;
goto out_unlock_free;
}
ss_del(&s);
if (signal_pending(current)) {
err = -ERESTARTNOHAND;
goto out_unlock_free;
}
}
msq->q_lspid = task_tgid_vnr(current);
msq->q_stime = get_seconds();
if (!pipelined_send(msq, msg)) {
/* noone is waiting for this message, enqueue it */
list_add_tail(&msg->m_list, &msq->q_messages);
msq->q_cbytes += msgsz;
msq->q_qnum++;
atomic_add(msgsz, &ns->msg_bytes);
atomic_inc(&ns->msg_hdrs);
}
err = 0;
msg = NULL;
out_unlock_free:
msg_unlock(msq);
out_free:
if (msg != NULL)
free_msg(msg);
return err;
}
asmlinkage long sys_msgsnd (int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg)
{
struct msg_queue *msq;
struct msg_msg *msg;
long mtype;
int err;
if (msgsz > msg_ctlmax || (long) msgsz < 0 || msqid < 0)
return -EINVAL;
if (get_user(mtype, &msgp->mtype))
return -EFAULT;
if (mtype < 1)
return -EINVAL;
msg = load_msg(msgp->mtext, msgsz);
if(IS_ERR(msg))
return PTR_ERR(msg);
msg->m_type = mtype;
msg->m_ts = msgsz;
msq = msg_lock(msqid);
err=-EINVAL;
if(msq==NULL)
goto out_free;
retry:
err= -EIDRM;
if (msg_checkid(msq,msqid))
goto out_unlock_free;
err=-EACCES;
if (ipcperms(&msq->q_perm, S_IWUGO))
goto out_unlock_free;
err = security_msg_queue_msgsnd(msq, msg, msgflg);
if (err)
goto out_unlock_free;
if(msgsz + msq->q_cbytes > msq->q_qbytes ||
1 + msq->q_qnum > msq->q_qbytes) {
struct msg_sender s;
if(msgflg&IPC_NOWAIT) {
err=-EAGAIN;
goto out_unlock_free;
}
ss_add(msq, &s);
msg_unlock(msq);
schedule();
current->state= TASK_RUNNING;
msq = msg_lock(msqid);
err = -EIDRM;
if(msq==NULL)
goto out_free;
ss_del(&s);
if (signal_pending(current)) {
err=-EINTR;
goto out_unlock_free;
}
goto retry;
}
msq->q_lspid = current->tgid;
msq->q_stime = get_seconds();
if(!pipelined_send(msq,msg)) {
/* noone is waiting for this message, enqueue it */
list_add_tail(&msg->m_list,&msq->q_messages);
msq->q_cbytes += msgsz;
msq->q_qnum++;
atomic_add(msgsz,&msg_bytes);
atomic_inc(&msg_hdrs);
}
err = 0;
msg = NULL;
out_unlock_free:
msg_unlock(msq);
out_free:
if(msg!=NULL)
free_msg(msg);
return err;
}