| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Hendrik Brueckner | 4980 | 99.24% | 17 | 60.71% |
| Sachin P. Sant | 19 | 0.38% | 1 | 3.57% |
| Ursula Braun-Krahl | 6 | 0.12% | 1 | 3.57% |
| Tejun Heo | 3 | 0.06% | 1 | 3.57% |
| Lucas De Marchi | 2 | 0.04% | 1 | 3.57% |
| Kees Cook | 2 | 0.04% | 1 | 3.57% |
| Jingoo Han | 1 | 0.02% | 1 | 3.57% |
| Rusty Russell | 1 | 0.02% | 1 | 3.57% |
| Sebastian Ott | 1 | 0.02% | 1 | 3.57% |
| Greg Kroah-Hartman | 1 | 0.02% | 1 | 3.57% |
| Alexey Dobriyan | 1 | 0.02% | 1 | 3.57% |
| Luis R. Rodriguez | 1 | 0.02% | 1 | 3.57% |
| Total | 5018 | 28 |
// SPDX-License-Identifier: GPL-2.0 /* * 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, 2013 * * 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 */ u8 info_path[16]; /* IUCV path info (dev attr) */ }; 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 *, u8 *); static void hvc_iucv_path_severed(struct iucv_path *, u8 *); 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) #define FILTER_WILDCARD_CHAR '*' 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. */ static 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 occurred 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 occurred. * 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_dtr_rts() - HVC notifier for handling DTR/RTS * @hp: Pointer the HVC device (struct hvc_struct) * @raise: Non-zero to raise or zero to lower DTR/RTS lines * * This routine notifies the HVC back-end to raise or lower DTR/RTS * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to * drop the IUCV connection (similar to hang up the modem). */ static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise) { struct hvc_iucv_private *priv; struct iucv_path *path; /* Raising the DTR/RTS is ignored as IUCV connections can be * established at any times. */ if (raise) return; priv = hvc_iucv_get_private(hp->vtermno); if (!priv) return; /* Lowering the DTR/RTS lines disconnects an established IUCV * connection. */ flush_sndbuf_sync(priv); spin_lock_bh(&priv->lock); path = priv->path; /* save reference to IUCV path */ priv->path = NULL; priv->iucv_state = IUCV_DISCONN; 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_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 cleans up tty resources. The clean-up of the IUCV * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios * control setting. * * Locking: struct hvc_iucv_private->lock */ static void hvc_iucv_notifier_del(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); destroy_tty_buffer_list(&priv->tty_outqueue); destroy_tty_buffer_list(&priv->tty_inqueue); priv->tty_state = TTY_CLOSED; priv->sndbuf_len = 0; spin_unlock_bh(&priv->lock); } /** * 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 that is specified with @ipvmid is permitted to * connect, otherwise non-zero. */ static int hvc_iucv_filter_connreq(u8 ipvmid[8]) { const char *wildcard, *filter_entry; size_t i, len; /* 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++) { filter_entry = hvc_iucv_filter + (8 * i); /* If a filter entry contains the filter wildcard character, * reduce the length to match the leading portion of the user * ID only (wildcard match). Characters following the wildcard * are ignored. */ wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR); len = (wildcard) ? wildcard - filter_entry : 8; if (0 == memcmp(ipvmid, filter_entry, len)) 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, u8 *ipuser) { struct hvc_iucv_private *priv, *tmp; u8 wildcard[9] = "lnxhvc "; int i, rc, find_unused; u8 nuser_data[16]; u8 vm_user_id[9]; ASCEBC(wildcard, sizeof(wildcard)); find_unused = !memcmp(wildcard, ipuser, 8); /* First, check if the pending path request is managed by this * IUCV handler: * - find a disconnected device if ipuser contains the wildcard * - find the device that matches the terminal ID in ipuser */ priv = NULL; for (i = 0; i < hvc_iucv_devices; i++) { tmp = hvc_iucv_table[i]; if (!tmp) continue; if (find_unused) { spin_lock(&tmp->lock); if (tmp->iucv_state == IUCV_DISCONN) priv = tmp; spin_unlock(&tmp->lock); } else if (!memcmp(tmp->srv_name, ipuser, 8)) priv = tmp; if (priv) 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; /* store path information */ memcpy(priv->info_path, ipvmid, 8); memcpy(priv->info_path + 8, ipuser + 8, 8); /* 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) { 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; } static ssize_t hvc_iucv_dev_termid_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hvc_iucv_private *priv = dev_get_drvdata(dev); size_t len; len = sizeof(priv->srv_name); memcpy(buf, priv->srv_name, len); EBCASC(buf, len); buf[len++] = '\n'; return len; } static ssize_t hvc_iucv_dev_state_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hvc_iucv_private *priv = dev_get_drvdata(dev); return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state); } static ssize_t hvc_iucv_dev_peer_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hvc_iucv_private *priv = dev_get_drvdata(dev); char vmid[9], ipuser[9]; memset(vmid, 0, sizeof(vmid)); memset(ipuser, 0, sizeof(ipuser)); spin_lock_bh(&priv->lock); if (priv->iucv_state == IUCV_CONNECTED) { memcpy(vmid, priv->info_path, 8); memcpy(ipuser, priv->info_path + 8, 8); } spin_unlock_bh(&priv->lock); EBCASC(ipuser, 8); return sprintf(buf, "%s:%s\n", vmid, ipuser); } /* 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, .dtr_rts = hvc_iucv_dtr_rts, }; /* 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, }; /* IUCV HVC device attributes */ static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); static struct attribute *hvc_iucv_dev_attrs[] = { &dev_attr_termid.attr, &dev_attr_state.attr, &dev_attr_peer.attr, NULL, }; static struct attribute_group hvc_iucv_dev_attr_group = { .attrs = hvc_iucv_dev_attrs, }; static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { &hvc_iucv_dev_attr_group, NULL, }; /** * 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->groups = hvc_iucv_dev_attr_groups; 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 * @dest: Location where to store the parsed z/VM user ID */ 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--; /* prohibit filter entries containing the wildcard character only */ if (len == 1 && *filter == FILTER_WILDCARD_CHAR) return ERR_PTR(-EINVAL); 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 = kcalloc(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 const 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: 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 kstrtoul(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);
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