diff options
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/scsi_netlink.c | 555 |
1 files changed, 15 insertions, 540 deletions
diff --git a/drivers/scsi/scsi_netlink.c b/drivers/scsi/scsi_netlink.c index 3252bc9625ee..65123a21b97e 100644 --- a/drivers/scsi/scsi_netlink.c +++ b/drivers/scsi/scsi_netlink.c @@ -33,40 +33,6 @@ struct sock *scsi_nl_sock = NULL; EXPORT_SYMBOL_GPL(scsi_nl_sock); -static DEFINE_SPINLOCK(scsi_nl_lock); -static struct list_head scsi_nl_drivers; - -static u32 scsi_nl_state; -#define STATE_EHANDLER_BSY 0x00000001 - -struct scsi_nl_transport { - int (*msg_handler)(struct sk_buff *); - void (*event_handler)(struct notifier_block *, unsigned long, void *); - unsigned int refcnt; - int flags; -}; - -/* flags values (bit flags) */ -#define HANDLER_DELETING 0x1 - -static struct scsi_nl_transport transports[SCSI_NL_MAX_TRANSPORTS] = - { {NULL, }, }; - - -struct scsi_nl_drvr { - struct list_head next; - int (*dmsg_handler)(struct Scsi_Host *shost, void *payload, - u32 len, u32 pid); - void (*devt_handler)(struct notifier_block *nb, - unsigned long event, void *notify_ptr); - struct scsi_host_template *hostt; - u64 vendor_id; - unsigned int refcnt; - int flags; -}; - - - /** * scsi_nl_rcv_msg - Receive message handler. * @skb: socket receive buffer @@ -81,7 +47,6 @@ scsi_nl_rcv_msg(struct sk_buff *skb) { struct nlmsghdr *nlh; struct scsi_nl_hdr *hdr; - unsigned long flags; u32 rlen; int err, tport; @@ -126,22 +91,24 @@ scsi_nl_rcv_msg(struct sk_buff *skb) /* * Deliver message to the appropriate transport */ - spin_lock_irqsave(&scsi_nl_lock, flags); - tport = hdr->transport; - if ((tport < SCSI_NL_MAX_TRANSPORTS) && - !(transports[tport].flags & HANDLER_DELETING) && - (transports[tport].msg_handler)) { - transports[tport].refcnt++; - spin_unlock_irqrestore(&scsi_nl_lock, flags); - err = transports[tport].msg_handler(skb); - spin_lock_irqsave(&scsi_nl_lock, flags); - transports[tport].refcnt--; - } else + if (tport == SCSI_NL_TRANSPORT) { + switch (hdr->msgtype) { + case SCSI_NL_SHOST_VENDOR: + /* Locate the driver that corresponds to the message */ + err = -ESRCH; + break; + default: + err = -EBADR; + break; + } + if (err) + printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n", + __func__, hdr->msgtype, err); + } + else err = -ENOENT; - spin_unlock_irqrestore(&scsi_nl_lock, flags); - next_msg: if ((err) || (nlh->nlmsg_flags & NLM_F_ACK)) netlink_ack(skb, nlh, err); @@ -150,333 +117,6 @@ next_msg: } } - -/** - * scsi_nl_rcv_event - Event handler for a netlink socket. - * @this: event notifier block - * @event: event type - * @ptr: event payload - * - **/ -static int -scsi_nl_rcv_event(struct notifier_block *this, unsigned long event, void *ptr) -{ - struct netlink_notify *n = ptr; - struct scsi_nl_drvr *driver; - unsigned long flags; - int tport; - - if (n->protocol != NETLINK_SCSITRANSPORT) - return NOTIFY_DONE; - - spin_lock_irqsave(&scsi_nl_lock, flags); - scsi_nl_state |= STATE_EHANDLER_BSY; - - /* - * Pass event on to any transports that may be listening - */ - for (tport = 0; tport < SCSI_NL_MAX_TRANSPORTS; tport++) { - if (!(transports[tport].flags & HANDLER_DELETING) && - (transports[tport].event_handler)) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - transports[tport].event_handler(this, event, ptr); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - } - - /* - * Pass event on to any drivers that may be listening - */ - list_for_each_entry(driver, &scsi_nl_drivers, next) { - if (!(driver->flags & HANDLER_DELETING) && - (driver->devt_handler)) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - driver->devt_handler(this, event, ptr); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - } - - scsi_nl_state &= ~STATE_EHANDLER_BSY; - spin_unlock_irqrestore(&scsi_nl_lock, flags); - - return NOTIFY_DONE; -} - -static struct notifier_block scsi_netlink_notifier = { - .notifier_call = scsi_nl_rcv_event, -}; - - -/* - * GENERIC SCSI transport receive and event handlers - */ - -/** - * scsi_generic_msg_handler - receive message handler for GENERIC transport messages - * @skb: socket receive buffer - **/ -static int -scsi_generic_msg_handler(struct sk_buff *skb) -{ - struct nlmsghdr *nlh = nlmsg_hdr(skb); - struct scsi_nl_hdr *snlh = NLMSG_DATA(nlh); - struct scsi_nl_drvr *driver; - struct Scsi_Host *shost; - unsigned long flags; - int err = 0, match, pid; - - pid = NETLINK_CREDS(skb)->pid; - - switch (snlh->msgtype) { - case SCSI_NL_SHOST_VENDOR: - { - struct scsi_nl_host_vendor_msg *msg = NLMSG_DATA(nlh); - - /* Locate the driver that corresponds to the message */ - spin_lock_irqsave(&scsi_nl_lock, flags); - match = 0; - list_for_each_entry(driver, &scsi_nl_drivers, next) { - if (driver->vendor_id == msg->vendor_id) { - match = 1; - break; - } - } - - if ((!match) || (!driver->dmsg_handler)) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - err = -ESRCH; - goto rcv_exit; - } - - if (driver->flags & HANDLER_DELETING) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - err = -ESHUTDOWN; - goto rcv_exit; - } - - driver->refcnt++; - spin_unlock_irqrestore(&scsi_nl_lock, flags); - - - /* if successful, scsi_host_lookup takes a shost reference */ - shost = scsi_host_lookup(msg->host_no); - if (!shost) { - err = -ENODEV; - goto driver_exit; - } - - /* is this host owned by the vendor ? */ - if (shost->hostt != driver->hostt) { - err = -EINVAL; - goto vendormsg_put; - } - - /* pass message on to the driver */ - err = driver->dmsg_handler(shost, (void *)&msg[1], - msg->vmsg_datalen, pid); - -vendormsg_put: - /* release reference by scsi_host_lookup */ - scsi_host_put(shost); - -driver_exit: - /* release our own reference on the registration object */ - spin_lock_irqsave(&scsi_nl_lock, flags); - driver->refcnt--; - spin_unlock_irqrestore(&scsi_nl_lock, flags); - break; - } - - default: - err = -EBADR; - break; - } - -rcv_exit: - if (err) - printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n", - __func__, snlh->msgtype, err); - return err; -} - - -/** - * scsi_nl_add_transport - - * Registers message and event handlers for a transport. Enables - * receipt of netlink messages and events to a transport. - * - * @tport: transport registering handlers - * @msg_handler: receive message handler callback - * @event_handler: receive event handler callback - **/ -int -scsi_nl_add_transport(u8 tport, - int (*msg_handler)(struct sk_buff *), - void (*event_handler)(struct notifier_block *, unsigned long, void *)) -{ - unsigned long flags; - int err = 0; - - if (tport >= SCSI_NL_MAX_TRANSPORTS) - return -EINVAL; - - spin_lock_irqsave(&scsi_nl_lock, flags); - - if (scsi_nl_state & STATE_EHANDLER_BSY) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - msleep(1); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - - if (transports[tport].msg_handler || transports[tport].event_handler) { - err = -EALREADY; - goto register_out; - } - - transports[tport].msg_handler = msg_handler; - transports[tport].event_handler = event_handler; - transports[tport].flags = 0; - transports[tport].refcnt = 0; - -register_out: - spin_unlock_irqrestore(&scsi_nl_lock, flags); - - return err; -} -EXPORT_SYMBOL_GPL(scsi_nl_add_transport); - - -/** - * scsi_nl_remove_transport - - * Disable transport receiption of messages and events - * - * @tport: transport deregistering handlers - * - **/ -void -scsi_nl_remove_transport(u8 tport) -{ - unsigned long flags; - - spin_lock_irqsave(&scsi_nl_lock, flags); - if (scsi_nl_state & STATE_EHANDLER_BSY) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - msleep(1); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - - if (tport < SCSI_NL_MAX_TRANSPORTS) { - transports[tport].flags |= HANDLER_DELETING; - - while (transports[tport].refcnt != 0) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - schedule_timeout_uninterruptible(HZ/4); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - transports[tport].msg_handler = NULL; - transports[tport].event_handler = NULL; - transports[tport].flags = 0; - } - - spin_unlock_irqrestore(&scsi_nl_lock, flags); - - return; -} -EXPORT_SYMBOL_GPL(scsi_nl_remove_transport); - - -/** - * scsi_nl_add_driver - - * A driver is registering its interfaces for SCSI netlink messages - * - * @vendor_id: A unique identification value for the driver. - * @hostt: address of the driver's host template. Used - * to verify an shost is bound to the driver - * @nlmsg_handler: receive message handler callback - * @nlevt_handler: receive event handler callback - * - * Returns: - * 0 on Success - * error result otherwise - **/ -int -scsi_nl_add_driver(u64 vendor_id, struct scsi_host_template *hostt, - int (*nlmsg_handler)(struct Scsi_Host *shost, void *payload, - u32 len, u32 pid), - void (*nlevt_handler)(struct notifier_block *nb, - unsigned long event, void *notify_ptr)) -{ - struct scsi_nl_drvr *driver; - unsigned long flags; - - driver = kzalloc(sizeof(*driver), GFP_KERNEL); - if (unlikely(!driver)) { - printk(KERN_ERR "%s: allocation failure\n", __func__); - return -ENOMEM; - } - - driver->dmsg_handler = nlmsg_handler; - driver->devt_handler = nlevt_handler; - driver->hostt = hostt; - driver->vendor_id = vendor_id; - - spin_lock_irqsave(&scsi_nl_lock, flags); - if (scsi_nl_state & STATE_EHANDLER_BSY) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - msleep(1); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - list_add_tail(&driver->next, &scsi_nl_drivers); - spin_unlock_irqrestore(&scsi_nl_lock, flags); - - return 0; -} -EXPORT_SYMBOL_GPL(scsi_nl_add_driver); - - -/** - * scsi_nl_remove_driver - - * An driver is unregistering with the SCSI netlink messages - * - * @vendor_id: The unique identification value for the driver. - **/ -void -scsi_nl_remove_driver(u64 vendor_id) -{ - struct scsi_nl_drvr *driver; - unsigned long flags; - - spin_lock_irqsave(&scsi_nl_lock, flags); - if (scsi_nl_state & STATE_EHANDLER_BSY) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - msleep(1); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - - list_for_each_entry(driver, &scsi_nl_drivers, next) { - if (driver->vendor_id == vendor_id) { - driver->flags |= HANDLER_DELETING; - while (driver->refcnt != 0) { - spin_unlock_irqrestore(&scsi_nl_lock, flags); - schedule_timeout_uninterruptible(HZ/4); - spin_lock_irqsave(&scsi_nl_lock, flags); - } - list_del(&driver->next); - kfree(driver); - spin_unlock_irqrestore(&scsi_nl_lock, flags); - return; - } - } - - spin_unlock_irqrestore(&scsi_nl_lock, flags); - - printk(KERN_ERR "%s: removal of driver failed - vendor_id 0x%llx\n", - __func__, (unsigned long long)vendor_id); - return; -} -EXPORT_SYMBOL_GPL(scsi_nl_remove_driver); - - /** * scsi_netlink_init - Called by SCSI subsystem to initialize * the SCSI transport netlink interface @@ -485,36 +125,19 @@ EXPORT_SYMBOL_GPL(scsi_nl_remove_driver); void scsi_netlink_init(void) { - int error; struct netlink_kernel_cfg cfg = { .input = scsi_nl_rcv_msg, .groups = SCSI_NL_GRP_CNT, }; - INIT_LIST_HEAD(&scsi_nl_drivers); - - error = netlink_register_notifier(&scsi_netlink_notifier); - if (error) { - printk(KERN_ERR "%s: register of event handler failed - %d\n", - __func__, error); - return; - } - scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT, &cfg); if (!scsi_nl_sock) { printk(KERN_ERR "%s: register of receive handler failed\n", __func__); - netlink_unregister_notifier(&scsi_netlink_notifier); return; } - /* Register the entry points for the generic SCSI transport */ - error = scsi_nl_add_transport(SCSI_NL_TRANSPORT, - scsi_generic_msg_handler, NULL); - if (error) - printk(KERN_ERR "%s: register of GENERIC transport handler" - " failed - %d\n", __func__, error); return; } @@ -526,158 +149,10 @@ scsi_netlink_init(void) void scsi_netlink_exit(void) { - scsi_nl_remove_transport(SCSI_NL_TRANSPORT); - if (scsi_nl_sock) { netlink_kernel_release(scsi_nl_sock); - netlink_unregister_notifier(&scsi_netlink_notifier); } return; } - -/* - * Exported Interfaces - */ - -/** - * scsi_nl_send_transport_msg - - * Generic function to send a single message from a SCSI transport to - * a single process - * - * @pid: receiving pid - * @hdr: message payload - * - **/ -void -scsi_nl_send_transport_msg(u32 pid, struct scsi_nl_hdr *hdr) -{ - struct sk_buff *skb; - struct nlmsghdr *nlh; - const char *fn; - char *datab; - u32 len, skblen; - int err; - - if (!scsi_nl_sock) { - err = -ENOENT; - fn = "netlink socket"; - goto msg_fail; - } - - len = NLMSG_SPACE(hdr->msglen); - skblen = NLMSG_SPACE(len); - - skb = alloc_skb(skblen, GFP_KERNEL); - if (!skb) { - err = -ENOBUFS; - fn = "alloc_skb"; - goto msg_fail; - } - - nlh = nlmsg_put(skb, pid, 0, SCSI_TRANSPORT_MSG, len - sizeof(*nlh), 0); - if (!nlh) { - err = -ENOBUFS; - fn = "nlmsg_put"; - goto msg_fail_skb; - } - datab = NLMSG_DATA(nlh); - memcpy(datab, hdr, hdr->msglen); - - err = nlmsg_unicast(scsi_nl_sock, skb, pid); - if (err < 0) { - fn = "nlmsg_unicast"; - /* nlmsg_unicast already kfree_skb'd */ - goto msg_fail; - } - - return; - -msg_fail_skb: - kfree_skb(skb); -msg_fail: - printk(KERN_WARNING - "%s: Dropped Message : pid %d Transport %d, msgtype x%x, " - "msglen %d: %s : err %d\n", - __func__, pid, hdr->transport, hdr->msgtype, hdr->msglen, - fn, err); - return; -} -EXPORT_SYMBOL_GPL(scsi_nl_send_transport_msg); - - -/** - * scsi_nl_send_vendor_msg - called to send a shost vendor unique message - * to a specific process id. - * - * @pid: process id of the receiver - * @host_no: host # sending the message - * @vendor_id: unique identifier for the driver's vendor - * @data_len: amount, in bytes, of vendor unique payload data - * @data_buf: pointer to vendor unique data buffer - * - * Returns: - * 0 on successful return - * otherwise, failing error code - * - * Notes: - * This routine assumes no locks are held on entry. - */ -int -scsi_nl_send_vendor_msg(u32 pid, unsigned short host_no, u64 vendor_id, - char *data_buf, u32 data_len) -{ - struct sk_buff *skb; - struct nlmsghdr *nlh; - struct scsi_nl_host_vendor_msg *msg; - u32 len, skblen; - int err; - - if (!scsi_nl_sock) { - err = -ENOENT; - goto send_vendor_fail; - } - - len = SCSI_NL_MSGALIGN(sizeof(*msg) + data_len); - skblen = NLMSG_SPACE(len); - - skb = alloc_skb(skblen, GFP_KERNEL); - if (!skb) { - err = -ENOBUFS; - goto send_vendor_fail; - } - - nlh = nlmsg_put(skb, 0, 0, SCSI_TRANSPORT_MSG, - skblen - sizeof(*nlh), 0); - if (!nlh) { - err = -ENOBUFS; - goto send_vendor_fail_skb; - } - msg = NLMSG_DATA(nlh); - - INIT_SCSI_NL_HDR(&msg->snlh, SCSI_NL_TRANSPORT, - SCSI_NL_SHOST_VENDOR, len); - msg->vendor_id = vendor_id; - msg->host_no = host_no; - msg->vmsg_datalen = data_len; /* bytes */ - memcpy(&msg[1], data_buf, data_len); - - err = nlmsg_unicast(scsi_nl_sock, skb, pid); - if (err) - /* nlmsg_multicast already kfree_skb'd */ - goto send_vendor_fail; - - return 0; - -send_vendor_fail_skb: - kfree_skb(skb); -send_vendor_fail: - printk(KERN_WARNING - "%s: Dropped SCSI Msg : host %d vendor_unique - err %d\n", - __func__, host_no, err); - return err; -} -EXPORT_SYMBOL(scsi_nl_send_vendor_msg); - - |