diff options
Diffstat (limited to 'drivers/scsi/scsi_netlink.c')
| -rw-r--r-- | drivers/scsi/scsi_netlink.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_netlink.c b/drivers/scsi/scsi_netlink.c new file mode 100644 index 000000000000..1b59b27e887f --- /dev/null +++ b/drivers/scsi/scsi_netlink.c @@ -0,0 +1,199 @@ +/* + * scsi_netlink.c - SCSI Transport Netlink Interface + * + * Copyright (C) 2006 James Smart, Emulex Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ +#include <linux/time.h> +#include <linux/jiffies.h> +#include <linux/security.h> +#include <net/sock.h> +#include <net/netlink.h> + +#include <scsi/scsi_netlink.h> +#include "scsi_priv.h" + +struct sock *scsi_nl_sock = NULL; +EXPORT_SYMBOL_GPL(scsi_nl_sock); + + +/** + * scsi_nl_rcv_msg - + * Receive message handler. Extracts message from a receive buffer. + * Validates message header and calls appropriate transport message handler + * + * @skb: socket receive buffer + * + **/ +static void +scsi_nl_rcv_msg(struct sk_buff *skb) +{ + struct nlmsghdr *nlh; + struct scsi_nl_hdr *hdr; + uint32_t rlen; + int err; + + while (skb->len >= NLMSG_SPACE(0)) { + err = 0; + + nlh = (struct nlmsghdr *) skb->data; + if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) || + (skb->len < nlh->nlmsg_len)) { + printk(KERN_WARNING "%s: discarding partial skb\n", + __FUNCTION__); + return; + } + + rlen = NLMSG_ALIGN(nlh->nlmsg_len); + if (rlen > skb->len) + rlen = skb->len; + + if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) { + err = -EBADMSG; + goto next_msg; + } + + hdr = NLMSG_DATA(nlh); + if ((hdr->version != SCSI_NL_VERSION) || + (hdr->magic != SCSI_NL_MAGIC)) { + err = -EPROTOTYPE; + goto next_msg; + } + + if (security_netlink_recv(skb, CAP_SYS_ADMIN)) { + err = -EPERM; + goto next_msg; + } + + if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) { + printk(KERN_WARNING "%s: discarding partial message\n", + __FUNCTION__); + return; + } + + /* + * We currently don't support anyone sending us a message + */ + +next_msg: + if ((err) || (nlh->nlmsg_flags & NLM_F_ACK)) + netlink_ack(skb, nlh, err); + + skb_pull(skb, rlen); + } +} + + +/** + * scsi_nl_rcv_msg - + * Receive handler for a socket. Extracts a received message buffer from + * the socket, and starts message processing. + * + * @sk: socket + * @len: unused + * + **/ +static void +scsi_nl_rcv(struct sock *sk, int len) +{ + struct sk_buff *skb; + + while ((skb = skb_dequeue(&sk->sk_receive_queue))) { + scsi_nl_rcv_msg(skb); + kfree_skb(skb); + } +} + + +/** + * 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; + + if (n->protocol != NETLINK_SCSITRANSPORT) + return NOTIFY_DONE; + + /* + * Currently, we are not tracking PID's, etc. There is nothing + * to handle. + */ + + return NOTIFY_DONE; +} + +static struct notifier_block scsi_netlink_notifier = { + .notifier_call = scsi_nl_rcv_event, +}; + + +/** + * scsi_netlink_init - + * Called by SCSI subsystem to intialize the SCSI transport netlink + * interface + * + **/ +void +scsi_netlink_init(void) +{ + int error; + + error = netlink_register_notifier(&scsi_netlink_notifier); + if (error) { + printk(KERN_ERR "%s: register of event handler failed - %d\n", + __FUNCTION__, error); + return; + } + + scsi_nl_sock = netlink_kernel_create(NETLINK_SCSITRANSPORT, + SCSI_NL_GRP_CNT, scsi_nl_rcv, THIS_MODULE); + if (!scsi_nl_sock) { + printk(KERN_ERR "%s: register of recieve handler failed\n", + __FUNCTION__); + netlink_unregister_notifier(&scsi_netlink_notifier); + } + + return; +} + + +/** + * scsi_netlink_exit - + * Called by SCSI subsystem to disable the SCSI transport netlink + * interface + * + **/ +void +scsi_netlink_exit(void) +{ + if (scsi_nl_sock) { + sock_release(scsi_nl_sock->sk_socket); + netlink_unregister_notifier(&scsi_netlink_notifier); + } + + return; +} + + |