From: [email protected] (Eric W. Biederman) Date: Fri, 07 Sep 2012 15:39:21 -0700
> > The scsi netlink code confuses the netlink port id with a process id, > going so far as to read NETLINK_CREDS(skb)->pid instead of the correct > NETLINK_CB(skb).pid. Fortunately it does not matter because nothing > registers to respond to scsi netlink requests. > > The only interesting use of the scsi_netlink interface is > fc_host_post_vendor_event which sends a netlink multicast message. > > Since nothing registers to handle scsi netlink messages kill all of the > registration logic, while retaining the same error handling behavior > preserving the userspace visible behavior and removing all of the > confused code that thought a netlink port id was a process id. > > This was tested with a kernel allyesconfig build which had no problems. > > Cc: James Bottomley <[email protected]> > Cc: James Smart <[email protected]> > Signed-off-by: "Eric W. Biederman" <[email protected]> James et al., please review and ACK. > --- > drivers/scsi/scsi_netlink.c | 555 > ++----------------------------------------- > include/scsi/scsi_netlink.h | 24 -- > 2 files changed, 15 insertions(+), 564 deletions(-) > > diff --git a/drivers/scsi/scsi_netlink.c b/drivers/scsi/scsi_netlink.c > index 8818dd6..abd43a3 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, > THIS_MODULE, &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); > - > - > diff --git a/include/scsi/scsi_netlink.h b/include/scsi/scsi_netlink.h > index 5cb20cc..62b4eda 100644 > --- a/include/scsi/scsi_netlink.h > +++ b/include/scsi/scsi_netlink.h > @@ -119,29 +119,5 @@ struct scsi_nl_host_vendor_msg { > (hdr)->msglen = mlen; \ > } > > - > -#ifdef __KERNEL__ > - > -#include <scsi/scsi_host.h> > - > -/* Exported Kernel Interfaces */ > -int scsi_nl_add_transport(u8 tport, > - int (*msg_handler)(struct sk_buff *), > - void (*event_handler)(struct notifier_block *, unsigned long, void *)); > -void scsi_nl_remove_transport(u8 tport); > - > -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)); > -void scsi_nl_remove_driver(u64 vendor_id); > - > -void scsi_nl_send_transport_msg(u32 pid, struct scsi_nl_hdr *hdr); > -int scsi_nl_send_vendor_msg(u32 pid, unsigned short host_no, u64 vendor_id, > - char *data_buf, u32 data_len); > - > -#endif /* __KERNEL__ */ > - > #endif /* SCSI_NETLINK_H */ > > -- > 1.7.5.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
