#define SEARCH_EQUAL 2
#define SEARCH_NOTEQUAL 3
#define SEARCH_LESSEQUAL 4
+#define SEARCH_NUMBER 5
#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
switch(mode)
{
case SEARCH_ANY:
+ case SEARCH_NUMBER:
return 1;
case SEARCH_LESSEQUAL:
if (msg->m_type <=type)
static inline int convert_mode(long *msgtyp, int msgflg)
{
+ if (msgflg & MSG_COPY)
+ return SEARCH_NUMBER;
/*
* find message of correct type.
* msgtyp = 0 => get first.
* This function creates new kernel message structure, large enough to store
* bufsz message bytes.
*/
-static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
- int msgflg, long *msgtyp,
- unsigned long *copy_number)
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
struct msg_msg *copy;
- *copy_number = *msgtyp;
- *msgtyp = 0;
/*
* Create dummy message to copy real message to.
*/
free_msg(copy);
}
#else
-static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
- int msgflg, long *msgtyp,
- unsigned long *copy_number)
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
return ERR_PTR(-ENOSYS);
}
}
#endif
+static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
+{
+ struct msg_msg *msg;
+ long count = 0;
+
+ list_for_each_entry(msg, &msq->q_messages, m_list) {
+ if (testmsg(msg, *msgtyp, mode) &&
+ !security_msg_queue_msgrcv(msq, msg, current,
+ *msgtyp, mode)) {
+ if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
+ *msgtyp = msg->m_type - 1;
+ } else if (mode == SEARCH_NUMBER) {
+ if (*msgtyp == count)
+ return msg;
+ } else
+ return msg;
+ count++;
+ }
+ }
+
+ return ERR_PTR(-EAGAIN);
+}
+
+
long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int msgflg,
long (*msg_handler)(void __user *, struct msg_msg *, size_t))
int mode;
struct ipc_namespace *ns;
struct msg_msg *copy = NULL;
- unsigned long copy_number = 0;
+
+ ns = current->nsproxy->ipc_ns;
if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
if (msgflg & MSG_COPY) {
- copy = prepare_copy(buf, bufsz, msgflg, &msgtyp, ©_number);
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
if (IS_ERR(copy))
return PTR_ERR(copy);
}
mode = convert_mode(&msgtyp, msgflg);
- ns = current->nsproxy->ipc_ns;
msq = msg_lock_check(ns, msqid);
if (IS_ERR(msq)) {
for (;;) {
struct msg_receiver msr_d;
- struct list_head *tmp;
- long msg_counter = 0;
msg = ERR_PTR(-EACCES);
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
goto out_unlock;
- msg = ERR_PTR(-EAGAIN);
- tmp = msq->q_messages.next;
- while (tmp != &msq->q_messages) {
- struct msg_msg *walk_msg;
-
- walk_msg = list_entry(tmp, struct msg_msg, m_list);
- if (testmsg(walk_msg, msgtyp, mode) &&
- !security_msg_queue_msgrcv(msq, walk_msg, current,
- msgtyp, mode)) {
-
- msg = walk_msg;
- if (mode == SEARCH_LESSEQUAL &&
- walk_msg->m_type != 1) {
- msgtyp = walk_msg->m_type - 1;
- } else if (msgflg & MSG_COPY) {
- if (copy_number == msg_counter) {
- /*
- * Found requested message.
- * Copy it.
- */
- msg = copy_msg(msg, copy);
- if (IS_ERR(msg))
- goto out_unlock;
- break;
- }
- } else
- break;
- msg_counter++;
- }
- tmp = tmp->next;
- }
+ msg = find_msg(msq, &msgtyp, mode);
+
if (!IS_ERR(msg)) {
/*
* Found a suitable message.
* If we are copying, then do not unlink message and do
* not update queue parameters.
*/
- if (msgflg & MSG_COPY)
+ if (msgflg & MSG_COPY) {
+ msg = copy_msg(msg, copy);
goto out_unlock;
+ }
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();