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
{
struct nlmsghdr *nlh;
struct scsi_nl_hdr *hdr;
- unsigned long flags;
u32 rlen;
int err, tport;
/*
* 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);
}
}
-
-/**
- * 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
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;
}
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);
-
-
projects / mirror_ubuntu-jammy-kernel.git / commitdiff