/*
- * hvc_iucv.c - z/VM IUCV back-end for the Hypervisor Console (HVC)
+ * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver
*
- * This back-end for HVC provides terminal access via
+ * This HVC device driver provides terminal access using
* z/VM IUCV communication paths.
*
- * Copyright IBM Corp. 2008.
+ * Copyright IBM Corp. 2008, 2009
*
* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
*/
#define KMSG_COMPONENT "hvc_iucv"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/types.h>
+#include <linux/slab.h>
#include <asm/ebcdic.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
#include <linux/mempool.h>
-#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/tty.h>
+#include <linux/wait.h>
#include <net/iucv/iucv.h>
#include "hvc_console.h"
-/* HVC backend for z/VM IUCV */
+/* General device driver settings */
#define HVC_IUCV_MAGIC 0xc9e4c3e5
#define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS
#define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4)
#define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */
#define MSG_TYPE_DATA 0x10 /* Terminal data */
-#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data))
struct iucv_tty_msg {
u8 version; /* Message version */
u8 type; /* Message type */
-#define MSG_MAX_DATALEN (~(u16)0)
+#define MSG_MAX_DATALEN ((u16)(~0))
u16 datalen; /* Payload length */
u8 data[]; /* Payload buffer */
} __attribute__((packed));
+#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data))
enum iucv_state_t {
IUCV_DISCONN = 0,
};
struct hvc_iucv_private {
- struct hvc_struct *hvc; /* HVC console struct reference */
+ struct hvc_struct *hvc; /* HVC struct reference */
u8 srv_name[8]; /* IUCV service name (ebcdic) */
+ unsigned char is_console; /* Linux console usage flag */
enum iucv_state_t iucv_state; /* IUCV connection status */
enum tty_state_t tty_state; /* TTY status */
struct iucv_path *path; /* IUCV path pointer */
spinlock_t lock; /* hvc_iucv_private lock */
+#define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */
+ void *sndbuf; /* send buffer */
+ size_t sndbuf_len; /* length of send buffer */
+#define QUEUE_SNDBUF_DELAY (HZ / 25)
+ struct delayed_work sndbuf_work; /* work: send iucv msg(s) */
+ wait_queue_head_t sndbuf_waitq; /* wait for send completion */
struct list_head tty_outqueue; /* outgoing IUCV messages */
struct list_head tty_inqueue; /* incoming IUCV messages */
+ struct device *dev; /* device structure */
};
struct iucv_tty_buffer {
struct list_head list; /* list pointer */
- struct iucv_message msg; /* store an incoming IUCV message */
+ struct iucv_message msg; /* store an IUCV message */
size_t offset; /* data buffer offset */
struct iucv_tty_msg *mbuf; /* buffer to store input/output data */
};
static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *);
-/* Kernel module parameters */
-static unsigned long hvc_iucv_devices;
+/* Kernel module parameter: use one terminal device as default */
+static unsigned long hvc_iucv_devices = 1;
/* Array of allocated hvc iucv tty lines... */
static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];
+#define IUCV_HVC_CON_IDX (0)
+/* List of z/VM user ID filter entries (struct iucv_vmid_filter) */
+#define MAX_VMID_FILTER (500)
+static size_t hvc_iucv_filter_size;
+static void *hvc_iucv_filter;
+static const char *hvc_iucv_filter_string;
+static DEFINE_RWLOCK(hvc_iucv_filter_lock);
/* Kmem cache and mempool for iucv_tty_buffer elements */
static struct kmem_cache *hvc_iucv_buffer_cache;
}
/**
- * alloc_tty_buffer() - Returns a new struct iucv_tty_buffer element.
+ * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element.
* @size: Size of the internal buffer used to store data.
* @flags: Memory allocation flags passed to mempool.
*
* This function allocates a new struct iucv_tty_buffer element and, optionally,
* allocates an internal data buffer with the specified size @size.
+ * The internal data buffer is always allocated with GFP_DMA which is
+ * required for receiving and sending data with IUCV.
* Note: The total message size arises from the internal buffer size and the
* members of the iucv_tty_msg structure.
- *
* The function returns NULL if memory allocation has failed.
*/
static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags)
bufp = mempool_alloc(hvc_iucv_mempool, flags);
if (!bufp)
return NULL;
- memset(bufp, 0, sizeof(struct iucv_tty_buffer));
+ memset(bufp, 0, sizeof(*bufp));
if (size > 0) {
bufp->msg.length = MSG_SIZE(size);
- bufp->mbuf = kmalloc(bufp->msg.length, flags);
+ bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA);
if (!bufp->mbuf) {
mempool_free(bufp, hvc_iucv_mempool);
return NULL;
/**
* destroy_tty_buffer() - destroy struct iucv_tty_buffer element.
* @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL.
- *
- * The destroy_tty_buffer() function frees the internal data buffer and returns
- * the struct iucv_tty_buffer element back to the mempool for freeing.
*/
static void destroy_tty_buffer(struct iucv_tty_buffer *bufp)
{
/**
* destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element.
- * @list: List head pointer to a list containing struct iucv_tty_buffer
- * elements.
- *
- * Calls destroy_tty_buffer() for each struct iucv_tty_buffer element in the
- * list @list.
+ * @list: List containing struct iucv_tty_buffer elements.
*/
static void destroy_tty_buffer_list(struct list_head *list)
{
}
/**
- * hvc_iucv_write() - Receive IUCV message write data to HVC console buffer.
- * @priv: Pointer to hvc_iucv_private structure.
- * @buf: HVC console buffer for writing received terminal data.
- * @count: HVC console buffer size.
+ * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer.
+ * @priv: Pointer to struct hvc_iucv_private
+ * @buf: HVC buffer for writing received terminal data.
+ * @count: HVC buffer size.
* @has_more_data: Pointer to an int variable.
*
* The function picks up pending messages from the input queue and receives
* the message data that is then written to the specified buffer @buf.
- * If the buffer size @count is less than the data message size, then the
+ * If the buffer size @count is less than the data message size, the
* message is kept on the input queue and @has_more_data is set to 1.
- * If the message data has been entirely written, the message is removed from
+ * If all message data has been written, the message is removed from
* the input queue.
*
* The function returns the number of bytes written to the terminal, zero if
* there are no pending data messages available or if there is no established
* IUCV path.
* If the IUCV path has been severed, then -EPIPE is returned to cause a
- * hang up (that is issued by the HVC console layer).
+ * hang up (that is issued by the HVC layer).
*/
static int hvc_iucv_write(struct hvc_iucv_private *priv,
char *buf, int count, int *has_more_data)
int written;
int rc;
- /* Immediately return if there is no IUCV connection */
+ /* immediately return if there is no IUCV connection */
if (priv->iucv_state == IUCV_DISCONN)
return 0;
- /* If the IUCV path has been severed, return -EPIPE to inform the
- * hvc console layer to hang up the tty device. */
+ /* if the IUCV path has been severed, return -EPIPE to inform the
+ * HVC layer to hang up the tty device. */
if (priv->iucv_state == IUCV_SEVERED)
return -EPIPE;
if (list_empty(&priv->tty_inqueue))
return 0;
- /* receive a iucv message and flip data to the tty (ldisc) */
+ /* receive an iucv message and flip data to the tty (ldisc) */
rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list);
written = 0;
if (!rb->mbuf) { /* message not yet received ... */
/* allocate mem to store msg data; if no memory is available
* then leave the buffer on the list and re-try later */
- rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC);
+ rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA);
if (!rb->mbuf)
return -ENOMEM;
case MSG_TYPE_WINSIZE:
if (rb->mbuf->datalen != sizeof(struct winsize))
break;
- hvc_resize(priv->hvc, *((struct winsize *)rb->mbuf->data));
+ /* The caller must ensure that the hvc is locked, which
+ * is the case when called from hvc_iucv_get_chars() */
+ __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
break;
case MSG_TYPE_ERROR: /* ignored ... */
* @buf: Pointer to a buffer to store data
* @count: Size of buffer available for writing
*
- * The hvc_console thread calls this method to read characters from
- * the terminal backend. If an IUCV communication path has been established,
- * pending IUCV messages are received and data is copied into buffer @buf
- * up to @count bytes.
+ * The HVC thread calls this method to read characters from the back-end.
+ * If an IUCV communication path has been established, pending IUCV messages
+ * are received and data is copied into buffer @buf up to @count bytes.
*
* Locking: The routine gets called under an irqsave() spinlock; and
* the routine locks the struct hvc_iucv_private->lock to call
}
/**
- * hvc_iucv_send() - Send an IUCV message containing terminal data.
+ * hvc_iucv_queue() - Buffer terminal data for sending.
* @priv: Pointer to struct hvc_iucv_private instance.
* @buf: Buffer containing data to send.
- * @size: Size of buffer and amount of data to send.
+ * @count: Size of buffer and amount of data to send.
*
- * If an IUCV communication path is established, the function copies the buffer
- * data to a newly allocated struct iucv_tty_buffer element, sends the data and
- * puts the element to the outqueue.
+ * The function queues data for sending. To actually send the buffered data,
+ * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY).
+ * The function returns the number of data bytes that has been buffered.
*
- * If there is no IUCV communication path established, the function returns 0.
- * If an existing IUCV communicaton path has been severed, the function returns
- * -EPIPE (can be passed to HVC layer to cause a tty hangup).
+ * If the device is not connected, data is ignored and the function returns
+ * @count.
+ * If the buffer is full, the function returns 0.
+ * If an existing IUCV communicaton path has been severed, -EPIPE is returned
+ * (that can be passed to HVC layer to cause a tty hangup).
*/
-static int hvc_iucv_send(struct hvc_iucv_private *priv, const char *buf,
- int count)
+static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf,
+ int count)
+{
+ size_t len;
+
+ if (priv->iucv_state == IUCV_DISCONN)
+ return count; /* ignore data */
+
+ if (priv->iucv_state == IUCV_SEVERED)
+ return -EPIPE;
+
+ len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len);
+ if (!len)
+ return 0;
+
+ memcpy(priv->sndbuf + priv->sndbuf_len, buf, len);
+ priv->sndbuf_len += len;
+
+ if (priv->iucv_state == IUCV_CONNECTED)
+ schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY);
+
+ return len;
+}
+
+/**
+ * hvc_iucv_send() - Send an IUCV message containing terminal data.
+ * @priv: Pointer to struct hvc_iucv_private instance.
+ *
+ * If an IUCV communication path has been established, the buffered output data
+ * is sent via an IUCV message and the number of bytes sent is returned.
+ * Returns 0 if there is no established IUCV communication path or
+ * -EPIPE if an existing IUCV communicaton path has been severed.
+ */
+static int hvc_iucv_send(struct hvc_iucv_private *priv)
{
struct iucv_tty_buffer *sb;
- int rc;
- u16 len;
+ int rc, len;
if (priv->iucv_state == IUCV_SEVERED)
return -EPIPE;
if (priv->iucv_state == IUCV_DISCONN)
- return 0;
+ return -EIO;
- len = min_t(u16, MSG_MAX_DATALEN, count);
+ if (!priv->sndbuf_len)
+ return 0;
/* allocate internal buffer to store msg data and also compute total
* message length */
- sb = alloc_tty_buffer(len, GFP_ATOMIC);
+ sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC);
if (!sb)
return -ENOMEM;
- sb->mbuf->datalen = len;
- memcpy(sb->mbuf->data, buf, len);
+ memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len);
+ sb->mbuf->datalen = (u16) priv->sndbuf_len;
+ sb->msg.length = MSG_SIZE(sb->mbuf->datalen);
list_add_tail(&sb->list, &priv->tty_outqueue);
rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
(void *) sb->mbuf, sb->msg.length);
if (rc) {
+ /* drop the message here; however we might want to handle
+ * 0x03 (msg limit reached) by trying again... */
list_del(&sb->list);
destroy_tty_buffer(sb);
- len = 0;
}
+ len = priv->sndbuf_len;
+ priv->sndbuf_len = 0;
return len;
}
/**
+ * hvc_iucv_sndbuf_work() - Send buffered data over IUCV
+ * @work: Work structure.
+ *
+ * This work queue function sends buffered output data over IUCV and,
+ * if not all buffered data could be sent, reschedules itself.
+ */
+static void hvc_iucv_sndbuf_work(struct work_struct *work)
+{
+ struct hvc_iucv_private *priv;
+
+ priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);
+ if (!priv)
+ return;
+
+ spin_lock_bh(&priv->lock);
+ hvc_iucv_send(priv);
+ spin_unlock_bh(&priv->lock);
+}
+
+/**
* hvc_iucv_put_chars() - HVC put_chars operation.
* @vtermno: HVC virtual terminal number.
* @buf: Pointer to an buffer to read data from
* @count: Size of buffer available for reading
*
- * The hvc_console thread calls this method to write characters from
- * to the terminal backend.
- * The function calls hvc_iucv_send() under the lock of the
- * struct hvc_iucv_private instance that corresponds to the tty @vtermno.
+ * The HVC thread calls this method to write characters to the back-end.
+ * The function calls hvc_iucv_queue() to queue terminal data for sending.
*
* Locking: The method gets called under an irqsave() spinlock; and
* locks struct hvc_iucv_private->lock.
static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
{
struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
- int sent;
+ int queued;
if (count <= 0)
return 0;
return -ENODEV;
spin_lock(&priv->lock);
- sent = hvc_iucv_send(priv, buf, count);
+ queued = hvc_iucv_queue(priv, buf, count);
spin_unlock(&priv->lock);
- return sent;
+ return queued;
}
/**
* @id: Additional data (originally passed to hvc_alloc): the index of an struct
* hvc_iucv_private instance.
*
- * The function sets the tty state to TTY_OPEN for the struct hvc_iucv_private
+ * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private
* instance that is derived from @id. Always returns 0.
*
* Locking: struct hvc_iucv_private->lock, spin_lock_bh
}
/**
- * hvc_iucv_cleanup() - Clean up function if the tty portion is finally closed.
+ * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.
* @priv: Pointer to the struct hvc_iucv_private instance.
- *
- * The functions severs the established IUCV communication path (if any), and
- * destroy struct iucv_tty_buffer elements from the in- and outqueue. Finally,
- * the functions resets the states to TTY_CLOSED and IUCV_DISCONN.
*/
static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
{
priv->tty_state = TTY_CLOSED;
priv->iucv_state = IUCV_DISCONN;
+
+ priv->sndbuf_len = 0;
}
/**
- * hvc_iucv_notifier_hangup() - HVC notifier for tty hangups.
- * @hp: Pointer to the HVC device (struct hvc_struct)
- * @id: Additional data (originally passed to hvc_alloc): the index of an struct
- * hvc_iucv_private instance.
+ * tty_outqueue_empty() - Test if the tty outq is empty
+ * @priv: Pointer to struct hvc_iucv_private instance.
+ */
+static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)
+{
+ int rc;
+
+ spin_lock_bh(&priv->lock);
+ rc = list_empty(&priv->tty_outqueue);
+ spin_unlock_bh(&priv->lock);
+
+ return rc;
+}
+
+/**
+ * flush_sndbuf_sync() - Flush send buffer and wait for completion
+ * @priv: Pointer to struct hvc_iucv_private instance.
*
- * This routine notifies the HVC backend that a tty hangup (carrier loss,
- * virtual or otherwise) has occured.
+ * The routine cancels a pending sndbuf work, calls hvc_iucv_send()
+ * to flush any buffered terminal output data and waits for completion.
+ */
+static void flush_sndbuf_sync(struct hvc_iucv_private *priv)
+{
+ int sync_wait;
+
+ cancel_delayed_work_sync(&priv->sndbuf_work);
+
+ spin_lock_bh(&priv->lock);
+ hvc_iucv_send(priv); /* force sending buffered data */
+ sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */
+ spin_unlock_bh(&priv->lock);
+
+ if (sync_wait)
+ wait_event_timeout(priv->sndbuf_waitq,
+ tty_outqueue_empty(priv), HZ/10);
+}
+
+/**
+ * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
+ * @priv: Pointer to hvc_iucv_private structure
+ *
+ * This routine severs an existing IUCV communication path and hangs
+ * up the underlying HVC terminal device.
+ * The hang-up occurs only if an IUCV communication path is established;
+ * otherwise there is no need to hang up the terminal device.
*
- * The HVC backend for z/VM IUCV ignores virtual hangups (vhangup()), to keep
- * an existing IUCV communication path established.
+ * The IUCV HVC hang-up is separated into two steps:
+ * 1. After the IUCV path has been severed, the iucv_state is set to
+ * IUCV_SEVERED.
+ * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
+ * IUCV_SEVERED state causes the tty hang-up in the HVC layer.
+ *
+ * If the tty has not yet been opened, clean up the hvc_iucv_private
+ * structure to allow re-connects.
+ * If the tty has been opened, let get_chars() return -EPIPE to signal
+ * the HVC layer to hang up the tty and, if so, wake up the HVC thread
+ * to call get_chars()...
+ *
+ * Special notes on hanging up a HVC terminal instantiated as console:
+ * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
+ * 2. do_tty_hangup() calls tty->ops->close() for console_filp
+ * => no hangup notifier is called by HVC (default)
+ * 2. hvc_close() returns because of tty_hung_up_p(filp)
+ * => no delete notifier is called!
+ * Finally, the back-end is not being notified, thus, the tty session is
+ * kept active (TTY_OPEN) to be ready for re-connects.
+ *
+ * Locking: spin_lock(&priv->lock) w/o disabling bh
+ */
+static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
+{
+ struct iucv_path *path;
+
+ path = NULL;
+ spin_lock(&priv->lock);
+ if (priv->iucv_state == IUCV_CONNECTED) {
+ path = priv->path;
+ priv->path = NULL;
+ priv->iucv_state = IUCV_SEVERED;
+ if (priv->tty_state == TTY_CLOSED)
+ hvc_iucv_cleanup(priv);
+ else
+ /* console is special (see above) */
+ if (priv->is_console) {
+ hvc_iucv_cleanup(priv);
+ priv->tty_state = TTY_OPENED;
+ } else
+ hvc_kick();
+ }
+ spin_unlock(&priv->lock);
+
+ /* finally sever path (outside of priv->lock due to lock ordering) */
+ if (path) {
+ iucv_path_sever(path, NULL);
+ iucv_path_free(path);
+ }
+}
+
+/**
+ * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.
+ * @hp: Pointer to the HVC device (struct hvc_struct)
+ * @id: Additional data (originally passed to hvc_alloc):
+ * the index of an struct hvc_iucv_private instance.
+ *
+ * This routine notifies the HVC back-end that a tty hangup (carrier loss,
+ * virtual or otherwise) has occured.
+ * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())
+ * to keep an existing IUCV communication path established.
* (Background: vhangup() is called from user space (by getty or login) to
* disable writing to the tty by other applications).
- *
- * If the tty has been opened (e.g. getty) and an established IUCV path has been
- * severed (we caused the tty hangup in that case), then the functions invokes
- * hvc_iucv_cleanup() to clean up.
+ * If the tty has been opened and an established IUCV path has been severed
+ * (we caused the tty hangup), the function calls hvc_iucv_cleanup().
*
* Locking: struct hvc_iucv_private->lock
*/
if (!priv)
return;
+ flush_sndbuf_sync(priv);
+
spin_lock_bh(&priv->lock);
/* NOTE: If the hangup was scheduled by ourself (from the iucv
- * path_servered callback [IUCV_SEVERED]), then we have to
- * finally clean up the tty backend structure and set state to
- * TTY_CLOSED.
- *
+ * path_servered callback [IUCV_SEVERED]), we have to clean up
+ * our structure and to set state to TTY_CLOSED.
* If the tty was hung up otherwise (e.g. vhangup()), then we
* ignore this hangup and keep an established IUCV path open...
* (...the reason is that we are not able to connect back to the
* @id: Additional data (originally passed to hvc_alloc):
* the index of an struct hvc_iucv_private instance.
*
- * This routine notifies the HVC backend that the last tty device file
- * descriptor has been closed.
- * The function calls hvc_iucv_cleanup() to clean up the struct hvc_iucv_private
- * instance.
+ * This routine notifies the HVC back-end that the last tty device fd has been
+ * closed. The function calls hvc_iucv_cleanup() to clean up the struct
+ * hvc_iucv_private instance.
*
* Locking: struct hvc_iucv_private->lock
*/
if (!priv)
return;
+ flush_sndbuf_sync(priv);
+
spin_lock_bh(&priv->lock);
path = priv->path; /* save reference to IUCV path */
priv->path = NULL;
}
/**
+ * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
+ * @ipvmid: Originating z/VM user ID (right padded with blanks)
+ *
+ * Returns 0 if the z/VM user ID @ipvmid is allowed to connection, otherwise
+ * non-zero.
+ */
+static int hvc_iucv_filter_connreq(u8 ipvmid[8])
+{
+ size_t i;
+
+ /* Note: default policy is ACCEPT if no filter is set */
+ if (!hvc_iucv_filter_size)
+ return 0;
+
+ for (i = 0; i < hvc_iucv_filter_size; i++)
+ if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8))
+ return 0;
+ return 1;
+}
+
+/**
* hvc_iucv_path_pending() - IUCV handler to process a connection request.
* @path: Pending path (struct iucv_path)
- * @ipvmid: Originator z/VM system identifier
+ * @ipvmid: z/VM system identifier of originator
* @ipuser: User specified data for this path
* (AF_IUCV: port/service name and originator port)
*
- * The function uses the @ipuser data to check to determine if the pending
- * path belongs to a terminal managed by this HVC backend.
- * If the check is successful, then an additional check is done to ensure
- * that a terminal cannot be accessed multiple times (only one connection
- * to a terminal is allowed). In that particular case, the pending path is
- * severed. If it is the first connection, the pending path is accepted and
- * associated to the struct hvc_iucv_private. The iucv state is updated to
- * reflect that a communication path has been established.
+ * The function uses the @ipuser data to determine if the pending path belongs
+ * to a terminal managed by this device driver.
+ * If the path belongs to this driver, ensure that the terminal is not accessed
+ * multiple times (only one connection to a terminal is allowed).
+ * If the terminal is not yet connected, the pending path is accepted and is
+ * associated to the appropriate struct hvc_iucv_private instance.
*
- * Returns 0 if the path belongs to a terminal managed by the this HVC backend;
+ * Returns 0 if @path belongs to a terminal managed by the this device driver;
* otherwise returns -ENODEV in order to dispatch this path to other handlers.
*
* Locking: struct hvc_iucv_private->lock
{
struct hvc_iucv_private *priv;
u8 nuser_data[16];
+ u8 vm_user_id[9];
int i, rc;
priv = NULL;
priv = hvc_iucv_table[i];
break;
}
-
if (!priv)
return -ENODEV;
+ /* Enforce that ipvmid is allowed to connect to us */
+ read_lock(&hvc_iucv_filter_lock);
+ rc = hvc_iucv_filter_connreq(ipvmid);
+ read_unlock(&hvc_iucv_filter_lock);
+ if (rc) {
+ iucv_path_sever(path, ipuser);
+ iucv_path_free(path);
+ memcpy(vm_user_id, ipvmid, 8);
+ vm_user_id[8] = 0;
+ pr_info("A connection request from z/VM user ID %s "
+ "was refused\n", vm_user_id);
+ return 0;
+ }
+
spin_lock(&priv->lock);
/* If the terminal is already connected or being severed, then sever
priv->path = path;
priv->iucv_state = IUCV_CONNECTED;
+ /* flush buffered output data... */
+ schedule_delayed_work(&priv->sndbuf_work, 5);
+
out_path_handled:
spin_unlock(&priv->lock);
return 0;
* @ipuser: User specified data for this path
* (AF_IUCV: port/service name and originator port)
*
- * The function also severs the path (as required by the IUCV protocol) and
- * sets the iucv state to IUCV_SEVERED for the associated struct
- * hvc_iucv_private instance. Later, the IUCV_SEVERED state triggers a tty
- * hangup (hvc_iucv_get_chars() / hvc_iucv_write()).
- *
- * If tty portion of the HVC is closed then clean up the outqueue in addition.
+ * This function calls the hvc_iucv_hangup() function for the
+ * respective IUCV HVC terminal.
*
* Locking: struct hvc_iucv_private->lock
*/
{
struct hvc_iucv_private *priv = path->private;
- spin_lock(&priv->lock);
- priv->iucv_state = IUCV_SEVERED;
-
- /* NOTE: If the tty has not yet been opened by a getty program
- * (e.g. to see console messages), then cleanup the
- * hvc_iucv_private structure to allow re-connects.
- *
- * If the tty has been opened, the get_chars() callback returns
- * -EPIPE to signal the hvc console layer to hang up the tty. */
- priv->path = NULL;
- if (priv->tty_state == TTY_CLOSED)
- hvc_iucv_cleanup(priv);
- spin_unlock(&priv->lock);
-
- /* finally sever path (outside of priv->lock due to lock ordering) */
- iucv_path_sever(path, ipuser);
- iucv_path_free(path);
+ hvc_iucv_hangup(priv);
}
/**
* @path: Pending path (struct iucv_path)
* @msg: Pointer to the IUCV message
*
- * The function stores an incoming message on the input queue for later
+ * The function puts an incoming message on the input queue for later
* processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
- * However, if the tty has not yet been opened, the message is rejected.
+ * If the tty has not yet been opened, the message is rejected.
*
* Locking: struct hvc_iucv_private->lock
*/
struct hvc_iucv_private *priv = path->private;
struct iucv_tty_buffer *rb;
+ /* reject messages that exceed max size of iucv_tty_msg->datalen */
+ if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {
+ iucv_message_reject(path, msg);
+ return;
+ }
+
spin_lock(&priv->lock);
/* reject messages if tty has not yet been opened */
goto unlock_return;
}
- /* allocate buffer an empty buffer element */
+ /* allocate tty buffer to save iucv msg only */
rb = alloc_tty_buffer(0, GFP_ATOMIC);
if (!rb) {
iucv_message_reject(path, msg);
list_add_tail(&rb->list, &priv->tty_inqueue);
- hvc_kick(); /* wakup hvc console thread */
+ hvc_kick(); /* wake up hvc thread */
unlock_return:
spin_unlock(&priv->lock);
* @path: Pending path (struct iucv_path)
* @msg: Pointer to the IUCV message
*
- * The function is called upon completion of message delivery and the
- * message is removed from the outqueue. Additional delivery information
- * can be found in msg->audit: rejected messages (0x040000 (IPADRJCT)) and
- * purged messages (0x010000 (IPADPGNR)).
+ * The function is called upon completion of message delivery to remove the
+ * message from the outqueue. Additional delivery information can be found
+ * msg->audit: rejected messages (0x040000 (IPADRJCT)), and
+ * purged messages (0x010000 (IPADPGNR)).
*
* Locking: struct hvc_iucv_private->lock
*/
list_move(&ent->list, &list_remove);
break;
}
+ wake_up(&priv->sndbuf_waitq);
spin_unlock(&priv->lock);
destroy_tty_buffer_list(&list_remove);
}
+/**
+ * hvc_iucv_pm_freeze() - Freeze PM callback
+ * @dev: IUVC HVC terminal device
+ *
+ * Sever an established IUCV communication path and
+ * trigger a hang-up of the underlying HVC terminal.
+ */
+static int hvc_iucv_pm_freeze(struct device *dev)
+{
+ struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+
+ local_bh_disable();
+ hvc_iucv_hangup(priv);
+ local_bh_enable();
+
+ return 0;
+}
+
+/**
+ * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback
+ * @dev: IUVC HVC terminal device
+ *
+ * Wake up the HVC thread to trigger hang-up and respective
+ * HVC back-end notifier invocations.
+ */
+static int hvc_iucv_pm_restore_thaw(struct device *dev)
+{
+ hvc_kick();
+ return 0;
+}
+
/* HVC operations */
-static struct hv_ops hvc_iucv_ops = {
+static const struct hv_ops hvc_iucv_ops = {
.get_chars = hvc_iucv_get_chars,
.put_chars = hvc_iucv_put_chars,
.notifier_add = hvc_iucv_notifier_add,
.notifier_hangup = hvc_iucv_notifier_hangup,
};
+/* Suspend / resume device operations */
+static const struct dev_pm_ops hvc_iucv_pm_ops = {
+ .freeze = hvc_iucv_pm_freeze,
+ .thaw = hvc_iucv_pm_restore_thaw,
+ .restore = hvc_iucv_pm_restore_thaw,
+};
+
+/* IUCV HVC device driver */
+static struct device_driver hvc_iucv_driver = {
+ .name = KMSG_COMPONENT,
+ .bus = &iucv_bus,
+ .pm = &hvc_iucv_pm_ops,
+};
+
/**
* hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
- * @id: hvc_iucv_table index
+ * @id: hvc_iucv_table index
+ * @is_console: Flag if the instance is used as Linux console
*
- * This function allocates a new hvc_iucv_private struct and put the
- * instance into hvc_iucv_table at index @id.
+ * This function allocates a new hvc_iucv_private structure and stores
+ * the instance in hvc_iucv_table at index @id.
* Returns 0 on success; otherwise non-zero.
*/
-static int __init hvc_iucv_alloc(int id)
+static int __init hvc_iucv_alloc(int id, unsigned int is_console)
{
struct hvc_iucv_private *priv;
char name[9];
spin_lock_init(&priv->lock);
INIT_LIST_HEAD(&priv->tty_outqueue);
INIT_LIST_HEAD(&priv->tty_inqueue);
+ INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);
+ init_waitqueue_head(&priv->sndbuf_waitq);
- /* Finally allocate hvc */
- priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id,
- HVC_IUCV_MAGIC + id, &hvc_iucv_ops, PAGE_SIZE);
+ priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);
+ if (!priv->sndbuf) {
+ kfree(priv);
+ return -ENOMEM;
+ }
+
+ /* set console flag */
+ priv->is_console = is_console;
+
+ /* allocate hvc device */
+ priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */
+ HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
if (IS_ERR(priv->hvc)) {
rc = PTR_ERR(priv->hvc);
- kfree(priv);
- return rc;
+ goto out_error_hvc;
}
+ /* notify HVC thread instead of using polling */
+ priv->hvc->irq_requested = 1;
+
/* setup iucv related information */
- snprintf(name, 9, "ihvc%-4d", id);
+ snprintf(name, 9, "lnxhvc%-2d", id);
memcpy(priv->srv_name, name, 8);
ASCEBC(priv->srv_name, 8);
+ /* create and setup device */
+ priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
+ if (!priv->dev) {
+ rc = -ENOMEM;
+ goto out_error_dev;
+ }
+ dev_set_name(priv->dev, "hvc_iucv%d", id);
+ dev_set_drvdata(priv->dev, priv);
+ priv->dev->bus = &iucv_bus;
+ priv->dev->parent = iucv_root;
+ priv->dev->driver = &hvc_iucv_driver;
+ priv->dev->release = (void (*)(struct device *)) kfree;
+ rc = device_register(priv->dev);
+ if (rc) {
+ put_device(priv->dev);
+ goto out_error_dev;
+ }
+
hvc_iucv_table[id] = priv;
return 0;
+
+out_error_dev:
+ hvc_remove(priv->hvc);
+out_error_hvc:
+ free_page((unsigned long) priv->sndbuf);
+ kfree(priv);
+
+ return rc;
}
/**
- * hvc_iucv_init() - Initialization of HVC backend for z/VM IUCV
+ * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
*/
-static int __init hvc_iucv_init(void)
+static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
{
- int rc, i;
+ hvc_remove(priv->hvc);
+ device_unregister(priv->dev);
+ free_page((unsigned long) priv->sndbuf);
+ kfree(priv);
+}
- if (!MACHINE_IS_VM) {
- pr_warning("The z/VM IUCV Hypervisor console cannot be "
- "used without z/VM.\n");
+/**
+ * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
+ * @filter: String containing a comma-separated list of z/VM user IDs
+ */
+static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
+{
+ const char *nextdelim, *residual;
+ size_t len;
+
+ nextdelim = strchr(filter, ',');
+ if (nextdelim) {
+ len = nextdelim - filter;
+ residual = nextdelim + 1;
+ } else {
+ len = strlen(filter);
+ residual = filter + len;
+ }
+
+ if (len == 0)
+ return ERR_PTR(-EINVAL);
+
+ /* check for '\n' (if called from sysfs) */
+ if (filter[len - 1] == '\n')
+ len--;
+
+ if (len > 8)
+ return ERR_PTR(-EINVAL);
+
+ /* pad with blanks and save upper case version of user ID */
+ memset(dest, ' ', 8);
+ while (len--)
+ dest[len] = toupper(filter[len]);
+ return residual;
+}
+
+/**
+ * hvc_iucv_setup_filter() - Set up z/VM user ID filter
+ * @filter: String consisting of a comma-separated list of z/VM user IDs
+ *
+ * The function parses the @filter string and creates an array containing
+ * the list of z/VM user ID filter entries.
+ * Return code 0 means success, -EINVAL if the filter is syntactically
+ * incorrect, -ENOMEM if there was not enough memory to allocate the
+ * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.
+ */
+static int hvc_iucv_setup_filter(const char *val)
+{
+ const char *residual;
+ int err;
+ size_t size, count;
+ void *array, *old_filter;
+
+ count = strlen(val);
+ if (count == 0 || (count == 1 && val[0] == '\n')) {
+ size = 0;
+ array = NULL;
+ goto out_replace_filter; /* clear filter */
+ }
+
+ /* count user IDs in order to allocate sufficient memory */
+ size = 1;
+ residual = val;
+ while ((residual = strchr(residual, ',')) != NULL) {
+ residual++;
+ size++;
+ }
+
+ /* check if the specified list exceeds the filter limit */
+ if (size > MAX_VMID_FILTER)
+ return -ENOSPC;
+
+ array = kzalloc(size * 8, GFP_KERNEL);
+ if (!array)
+ return -ENOMEM;
+
+ count = size;
+ residual = val;
+ while (*residual && count) {
+ residual = hvc_iucv_parse_filter(residual,
+ array + ((size - count) * 8));
+ if (IS_ERR(residual)) {
+ err = PTR_ERR(residual);
+ kfree(array);
+ goto out_err;
+ }
+ count--;
+ }
+
+out_replace_filter:
+ write_lock_bh(&hvc_iucv_filter_lock);
+ old_filter = hvc_iucv_filter;
+ hvc_iucv_filter_size = size;
+ hvc_iucv_filter = array;
+ write_unlock_bh(&hvc_iucv_filter_lock);
+ kfree(old_filter);
+
+ err = 0;
+out_err:
+ return err;
+}
+
+/**
+ * param_set_vmidfilter() - Set z/VM user ID filter parameter
+ * @val: String consisting of a comma-separated list of z/VM user IDs
+ * @kp: Kernel parameter pointing to hvc_iucv_filter array
+ *
+ * The function sets up the z/VM user ID filter specified as comma-separated
+ * list of user IDs in @val.
+ * Note: If it is called early in the boot process, @val is stored and
+ * parsed later in hvc_iucv_init().
+ */
+static int param_set_vmidfilter(const char *val, struct kernel_param *kp)
+{
+ int rc;
+
+ if (!MACHINE_IS_VM || !hvc_iucv_devices)
return -ENODEV;
+
+ if (!val)
+ return -EINVAL;
+
+ rc = 0;
+ if (slab_is_available())
+ rc = hvc_iucv_setup_filter(val);
+ else
+ hvc_iucv_filter_string = val; /* defer... */
+ return rc;
+}
+
+/**
+ * param_get_vmidfilter() - Get z/VM user ID filter
+ * @buffer: Buffer to store z/VM user ID filter,
+ * (buffer size assumption PAGE_SIZE)
+ * @kp: Kernel parameter pointing to the hvc_iucv_filter array
+ *
+ * The function stores the filter as a comma-separated list of z/VM user IDs
+ * in @buffer. Typically, sysfs routines call this function for attr show.
+ */
+static int param_get_vmidfilter(char *buffer, struct kernel_param *kp)
+{
+ int rc;
+ size_t index, len;
+ void *start, *end;
+
+ if (!MACHINE_IS_VM || !hvc_iucv_devices)
+ return -ENODEV;
+
+ rc = 0;
+ read_lock_bh(&hvc_iucv_filter_lock);
+ for (index = 0; index < hvc_iucv_filter_size; index++) {
+ start = hvc_iucv_filter + (8 * index);
+ end = memchr(start, ' ', 8);
+ len = (end) ? end - start : 8;
+ memcpy(buffer + rc, start, len);
+ rc += len;
+ buffer[rc++] = ',';
}
+ read_unlock_bh(&hvc_iucv_filter_lock);
+ if (rc)
+ buffer[--rc] = '\0'; /* replace last comma and update rc */
+ return rc;
+}
+
+#define param_check_vmidfilter(name, p) __param_check(name, p, void)
+
+/**
+ * hvc_iucv_init() - z/VM IUCV HVC device driver initialization
+ */
+static int __init hvc_iucv_init(void)
+{
+ int rc;
+ unsigned int i;
if (!hvc_iucv_devices)
return -ENODEV;
- if (hvc_iucv_devices > MAX_HVC_IUCV_LINES)
- return -EINVAL;
+ if (!MACHINE_IS_VM) {
+ pr_notice("The z/VM IUCV HVC device driver cannot "
+ "be used without z/VM\n");
+ rc = -ENODEV;
+ goto out_error;
+ }
+
+ if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {
+ pr_err("%lu is not a valid value for the hvc_iucv= "
+ "kernel parameter\n", hvc_iucv_devices);
+ rc = -EINVAL;
+ goto out_error;
+ }
+
+ /* register IUCV HVC device driver */
+ rc = driver_register(&hvc_iucv_driver);
+ if (rc)
+ goto out_error;
+
+ /* parse hvc_iucv_allow string and create z/VM user ID filter list */
+ if (hvc_iucv_filter_string) {
+ rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
+ switch (rc) {
+ case 0:
+ break;
+ case -ENOMEM:
+ pr_err("Allocating memory failed with "
+ "reason code=%d\n", 3);
+ goto out_error;
+ case -EINVAL:
+ pr_err("hvc_iucv_allow= does not specify a valid "
+ "z/VM user ID list\n");
+ goto out_error;
+ case -ENOSPC:
+ pr_err("hvc_iucv_allow= specifies too many "
+ "z/VM user IDs\n");
+ goto out_error;
+ default:
+ goto out_error;
+ }
+ }
hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
sizeof(struct iucv_tty_buffer),
0, 0, NULL);
if (!hvc_iucv_buffer_cache) {
- pr_err("Not enough memory for driver initialization "
- "(rs=%d).\n", 1);
- return -ENOMEM;
+ pr_err("Allocating memory failed with reason code=%d\n", 1);
+ rc = -ENOMEM;
+ goto out_error;
}
hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
hvc_iucv_buffer_cache);
if (!hvc_iucv_mempool) {
- pr_err("Not enough memory for driver initialization "
- "(rs=%d).\n", 2);
+ pr_err("Allocating memory failed with reason code=%d\n", 2);
kmem_cache_destroy(hvc_iucv_buffer_cache);
- return -ENOMEM;
+ rc = -ENOMEM;
+ goto out_error;
+ }
+
+ /* register the first terminal device as console
+ * (must be done before allocating hvc terminal devices) */
+ rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
+ if (rc) {
+ pr_err("Registering HVC terminal device as "
+ "Linux console failed\n");
+ goto out_error_memory;
}
/* allocate hvc_iucv_private structs */
for (i = 0; i < hvc_iucv_devices; i++) {
- rc = hvc_iucv_alloc(i);
+ rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);
if (rc) {
- pr_err("Could not create new z/VM IUCV HVC backend "
- "rc=%d.\n", rc);
+ pr_err("Creating a new HVC terminal device "
+ "failed with error code=%d\n", rc);
goto out_error_hvc;
}
}
/* register IUCV callback handler */
rc = iucv_register(&hvc_iucv_handler, 0);
if (rc) {
- pr_err("Could not register iucv handler (rc=%d).\n", rc);
+ pr_err("Registering IUCV handlers failed with error code=%d\n",
+ rc);
goto out_error_iucv;
}
iucv_unregister(&hvc_iucv_handler, 0);
out_error_hvc:
for (i = 0; i < hvc_iucv_devices; i++)
- if (hvc_iucv_table[i]) {
- if (hvc_iucv_table[i]->hvc)
- hvc_remove(hvc_iucv_table[i]->hvc);
- kfree(hvc_iucv_table[i]);
- }
+ if (hvc_iucv_table[i])
+ hvc_iucv_destroy(hvc_iucv_table[i]);
+out_error_memory:
mempool_destroy(hvc_iucv_mempool);
kmem_cache_destroy(hvc_iucv_buffer_cache);
+out_error:
+ if (hvc_iucv_filter)
+ kfree(hvc_iucv_filter);
+ hvc_iucv_devices = 0; /* ensure that we do not provide any device */
return rc;
}
/**
- * hvc_iucv_console_init() - Early console initialization
- */
-static int __init hvc_iucv_console_init(void)
-{
- if (!MACHINE_IS_VM || !hvc_iucv_devices)
- return -ENODEV;
- return hvc_instantiate(HVC_IUCV_MAGIC, 0, &hvc_iucv_ops);
-}
-
-/**
* hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter
* @val: Parameter value (numeric)
*/
}
-module_init(hvc_iucv_init);
-console_initcall(hvc_iucv_console_init);
+device_initcall(hvc_iucv_init);
__setup("hvc_iucv=", hvc_iucv_config);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("HVC back-end for z/VM IUCV.");
-MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");
+core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff