diff options
Diffstat (limited to 'drivers/char/hvc_iucv.c')
| -rw-r--r-- | drivers/char/hvc_iucv.c | 1337 |
1 files changed, 0 insertions, 1337 deletions
diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c deleted file mode 100644 index c3425bb3a1f..00000000000 --- a/drivers/char/hvc_iucv.c +++ /dev/null @@ -1,1337 +0,0 @@ -/* - * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver - * - * This HVC device driver provides terminal access using - * z/VM IUCV communication paths. - * - * 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/moduleparam.h> -#include <linux/tty.h> -#include <linux/wait.h> -#include <net/iucv/iucv.h> - -#include "hvc_console.h" - - -/* 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) - -/* IUCV TTY message */ -#define MSG_VERSION 0x02 /* Message version */ -#define MSG_TYPE_ERROR 0x01 /* Error message */ -#define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ -#define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ -#define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ -#define MSG_TYPE_DATA 0x10 /* Terminal data */ - -struct iucv_tty_msg { - u8 version; /* Message version */ - u8 type; /* Message type */ -#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, - IUCV_CONNECTED = 1, - IUCV_SEVERED = 2, -}; - -enum tty_state_t { - TTY_CLOSED = 0, - TTY_OPENED = 1, -}; - -struct hvc_iucv_private { - 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 IUCV message */ - size_t offset; /* data buffer offset */ - struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ -}; - -/* IUCV callback handler */ -static int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]); -static void hvc_iucv_path_severed(struct iucv_path *, u8[16]); -static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); -static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); - - -/* 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; -static mempool_t *hvc_iucv_mempool; - -/* IUCV handler callback functions */ -static struct iucv_handler hvc_iucv_handler = { - .path_pending = hvc_iucv_path_pending, - .path_severed = hvc_iucv_path_severed, - .message_complete = hvc_iucv_msg_complete, - .message_pending = hvc_iucv_msg_pending, -}; - - -/** - * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. - * @num: The HVC virtual terminal number (vtermno) - * - * This function returns the struct hvc_iucv_private instance that corresponds - * to the HVC virtual terminal number specified as parameter @num. - */ -struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) -{ - if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) - return NULL; - return hvc_iucv_table[num - HVC_IUCV_MAGIC]; -} - -/** - * 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) -{ - struct iucv_tty_buffer *bufp; - - bufp = mempool_alloc(hvc_iucv_mempool, flags); - if (!bufp) - return NULL; - memset(bufp, 0, sizeof(*bufp)); - - if (size > 0) { - bufp->msg.length = MSG_SIZE(size); - bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA); - if (!bufp->mbuf) { - mempool_free(bufp, hvc_iucv_mempool); - return NULL; - } - bufp->mbuf->version = MSG_VERSION; - bufp->mbuf->type = MSG_TYPE_DATA; - bufp->mbuf->datalen = (u16) size; - } - return bufp; -} - -/** - * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. - * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. - */ -static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) -{ - kfree(bufp->mbuf); - mempool_free(bufp, hvc_iucv_mempool); -} - -/** - * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. - * @list: List containing struct iucv_tty_buffer elements. - */ -static void destroy_tty_buffer_list(struct list_head *list) -{ - struct iucv_tty_buffer *ent, *next; - - list_for_each_entry_safe(ent, next, list, list) { - list_del(&ent->list); - destroy_tty_buffer(ent); - } -} - -/** - * 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, the - * message is kept on the input queue and @has_more_data is set to 1. - * 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 layer). - */ -static int hvc_iucv_write(struct hvc_iucv_private *priv, - char *buf, int count, int *has_more_data) -{ - struct iucv_tty_buffer *rb; - int written; - int rc; - - /* 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 layer to hang up the tty device. */ - if (priv->iucv_state == IUCV_SEVERED) - return -EPIPE; - - /* check if there are pending messages */ - if (list_empty(&priv->tty_inqueue)) - return 0; - - /* 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 | GFP_DMA); - if (!rb->mbuf) - return -ENOMEM; - - rc = __iucv_message_receive(priv->path, &rb->msg, 0, - rb->mbuf, rb->msg.length, NULL); - switch (rc) { - case 0: /* Successful */ - break; - case 2: /* No message found */ - case 9: /* Message purged */ - break; - default: - written = -EIO; - } - /* remove buffer if an error has occured or received data - * is not correct */ - if (rc || (rb->mbuf->version != MSG_VERSION) || - (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) - goto out_remove_buffer; - } - - switch (rb->mbuf->type) { - case MSG_TYPE_DATA: - written = min_t(int, rb->mbuf->datalen - rb->offset, count); - memcpy(buf, rb->mbuf->data + rb->offset, written); - if (written < (rb->mbuf->datalen - rb->offset)) { - rb->offset += written; - *has_more_data = 1; - goto out_written; - } - break; - - case MSG_TYPE_WINSIZE: - if (rb->mbuf->datalen != sizeof(struct winsize)) - break; - /* 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 ... */ - case MSG_TYPE_TERMENV: /* ignored ... */ - case MSG_TYPE_TERMIOS: /* ignored ... */ - break; - } - -out_remove_buffer: - list_del(&rb->list); - destroy_tty_buffer(rb); - *has_more_data = !list_empty(&priv->tty_inqueue); - -out_written: - return written; -} - -/** - * hvc_iucv_get_chars() - HVC get_chars operation. - * @vtermno: HVC virtual terminal number. - * @buf: Pointer to a buffer to store data - * @count: Size of buffer available for writing - * - * 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 - * helper functions. - */ -static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) -{ - struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); - int written; - int has_more_data; - - if (count <= 0) - return 0; - - if (!priv) - return -ENODEV; - - spin_lock(&priv->lock); - has_more_data = 0; - written = hvc_iucv_write(priv, buf, count, &has_more_data); - spin_unlock(&priv->lock); - - /* if there are still messages on the queue... schedule another run */ - if (has_more_data) - hvc_kick(); - - return written; -} - -/** - * hvc_iucv_queue() - Buffer terminal data for sending. - * @priv: Pointer to struct hvc_iucv_private instance. - * @buf: Buffer containing data to send. - * @count: Size of buffer and amount of data to send. - * - * 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 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_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, len; - - if (priv->iucv_state == IUCV_SEVERED) - return -EPIPE; - - if (priv->iucv_state == IUCV_DISCONN) - return -EIO; - - if (!priv->sndbuf_len) - return 0; - - /* allocate internal buffer to store msg data and also compute total - * message length */ - sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); - if (!sb) - return -ENOMEM; - - 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 = 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 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 queued; - - if (count <= 0) - return 0; - - if (!priv) - return -ENODEV; - - spin_lock(&priv->lock); - queued = hvc_iucv_queue(priv, buf, count); - spin_unlock(&priv->lock); - - return queued; -} - -/** - * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. - * @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. - * - * 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 - */ -static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) -{ - struct hvc_iucv_private *priv; - - priv = hvc_iucv_get_private(id); - if (!priv) - return 0; - - spin_lock_bh(&priv->lock); - priv->tty_state = TTY_OPENED; - spin_unlock_bh(&priv->lock); - - return 0; -} - -/** - * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. - * @priv: Pointer to the struct hvc_iucv_private instance. - */ -static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) -{ - destroy_tty_buffer_list(&priv->tty_outqueue); - destroy_tty_buffer_list(&priv->tty_inqueue); - - priv->tty_state = TTY_CLOSED; - priv->iucv_state = IUCV_DISCONN; - - priv->sndbuf_len = 0; -} - -/** - * 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. - * - * 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 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 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 - */ -static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) -{ - struct hvc_iucv_private *priv; - - priv = hvc_iucv_get_private(id); - 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]), 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 - * client if we disconnect on hang up) */ - priv->tty_state = TTY_CLOSED; - - if (priv->iucv_state == IUCV_SEVERED) - hvc_iucv_cleanup(priv); - spin_unlock_bh(&priv->lock); -} - -/** - * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. - * @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 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 - */ -static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) -{ - struct hvc_iucv_private *priv; - struct iucv_path *path; - - priv = hvc_iucv_get_private(id); - 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_cleanup(priv); - spin_unlock_bh(&priv->lock); - - /* sever IUCV path outside of priv->lock due to lock ordering of: - * priv->lock <--> iucv_table_lock */ - if (path) { - iucv_path_sever(path, NULL); - iucv_path_free(path); - } -} - -/** - * 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: 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 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 @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 - */ -static int hvc_iucv_path_pending(struct iucv_path *path, - u8 ipvmid[8], u8 ipuser[16]) -{ - struct hvc_iucv_private *priv; - u8 nuser_data[16]; - u8 vm_user_id[9]; - int i, rc; - - priv = NULL; - for (i = 0; i < hvc_iucv_devices; i++) - if (hvc_iucv_table[i] && - (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) { - 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 - * this path to enforce that there is only ONE established communication - * path per terminal. */ - if (priv->iucv_state != IUCV_DISCONN) { - iucv_path_sever(path, ipuser); - iucv_path_free(path); - goto out_path_handled; - } - - /* accept path */ - memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ - memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ - path->msglim = 0xffff; /* IUCV MSGLIMIT */ - path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ - rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); - if (rc) { - iucv_path_sever(path, ipuser); - iucv_path_free(path); - goto out_path_handled; - } - 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; -} - -/** - * hvc_iucv_path_severed() - IUCV handler to process a path sever. - * @path: Pending path (struct iucv_path) - * @ipuser: User specified data for this path - * (AF_IUCV: port/service name and originator port) - * - * This function calls the hvc_iucv_hangup() function for the - * respective IUCV HVC terminal. - * - * Locking: struct hvc_iucv_private->lock - */ -static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) -{ - struct hvc_iucv_private *priv = path->private; - - hvc_iucv_hangup(priv); -} - -/** - * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. - * @path: Pending path (struct iucv_path) - * @msg: Pointer to the IUCV message - * - * The function puts an incoming message on the input queue for later - * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). - * If the tty has not yet been opened, the message is rejected. - * - * Locking: struct hvc_iucv_private->lock - */ -static void hvc_iucv_msg_pending(struct iucv_path *path, - struct iucv_message *msg) -{ - 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 */ - if (priv->tty_state == TTY_CLOSED) { - iucv_message_reject(path, msg); - goto unlock_return; - } - - /* allocate tty buffer to save iucv msg only */ - rb = alloc_tty_buffer(0, GFP_ATOMIC); - if (!rb) { - iucv_message_reject(path, msg); - goto unlock_return; /* -ENOMEM */ - } - rb->msg = *msg; - - list_add_tail(&rb->list, &priv->tty_inqueue); - - hvc_kick(); /* wake up hvc thread */ - -unlock_return: - spin_unlock(&priv->lock); -} - -/** - * hvc_iucv_msg_complete() - IUCV handler to process message completion - * @path: Pending path (struct iucv_path) - * @msg: Pointer to the IUCV message - * - * 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 - */ -static void hvc_iucv_msg_complete(struct iucv_path *path, - struct iucv_message *msg) -{ - struct hvc_iucv_private *priv = path->private; - struct iucv_tty_buffer *ent, *next; - LIST_HEAD(list_remove); - - spin_lock(&priv->lock); - list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) - if (ent->msg.id == msg->id) { - 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 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_del = hvc_iucv_notifier_del, - .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 - * @is_console: Flag if the instance is used as Linux console - * - * 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, unsigned int is_console) -{ - struct hvc_iucv_private *priv; - char name[9]; - int rc; - - priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); - if (!priv) - return -ENOMEM; - - 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); - - 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); - goto out_error_hvc; - } - - /* notify HVC thread instead of using polling */ - priv->hvc->irq_requested = 1; - - /* setup iucv related information */ - 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_destroy() - Destroy and free hvc_iucv_private instances - */ -static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) -{ - hvc_remove(priv->hvc); - device_unregister(priv->dev); - free_page((unsigned long) priv->sndbuf); - kfree(priv); -} - -/** - * 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, const 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, const 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) - -static struct kernel_param_ops param_ops_vmidfilter = { - .set = param_set_vmidfilter, - .get = param_get_vmidfilter, -}; - -/** - * 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 (!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("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("Allocating memory failed with reason code=%d\n", 2); - kmem_cache_destroy(hvc_iucv_buffer_cache); - 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, (i == IUCV_HVC_CON_IDX) ? 1 : 0); - if (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("Registering IUCV handlers failed with error code=%d\n", - rc); - goto out_error_hvc; - } - - return 0; - -out_error_hvc: - for (i = 0; i < hvc_iucv_devices; 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_config() - Parsing of hvc_iucv= kernel command line parameter - * @val: Parameter value (numeric) - */ -static int __init hvc_iucv_config(char *val) -{ - return strict_strtoul(val, 10, &hvc_iucv_devices); -} - - -device_initcall(hvc_iucv_init); -__setup("hvc_iucv=", hvc_iucv_config); -core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); |