/* * 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 = nlmsg_hdr(skb); 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; return; } 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_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(&init_net, NETLINK_SCSITRANSPORT, SCSI_NL_GRP_CNT, scsi_nl_rcv_msg, NULL, 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; }