#include <linux/time.h>
#include <linux/jiffies.h>
#include <linux/security.h>
+#include <linux/delay.h>
#include <net/sock.h>
#include <net/netlink.h>
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.
{
struct nlmsghdr *nlh;
struct scsi_nl_hdr *hdr;
- uint32_t rlen;
- int err;
+ unsigned long flags;
+ u32 rlen;
+ int err, tport;
while (skb->len >= NLMSG_SPACE(0)) {
err = 0;
if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
err = -EBADMSG;
- return;
+ goto next_msg;
}
hdr = NLMSG_DATA(nlh);
if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
printk(KERN_WARNING "%s: discarding partial message\n",
__func__);
- return;
+ goto next_msg;
}
/*
- * We currently don't support anyone sending us a message
+ * 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
+ err = -ENOENT;
+
+ spin_unlock_irqrestore(&scsi_nl_lock, flags);
next_msg:
if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
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;
+
/*
- * Currently, we are not tracking PID's, etc. There is nothing
- * to handle.
+ * 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;
}
/**
- * scsi_netlink_init - Called by SCSI subsystem to intialize the SCSI transport netlink interface
+ * 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 intialize
+ * the SCSI transport netlink interface
*
**/
void
{
int error;
+ 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",
printk(KERN_ERR "%s: register of recieve 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;
}
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);
}
+/*
+ * 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 succesful 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);
+
+
projects / linux-beck.git / commitdiff