LXR linux/drivers/scsi/scsi

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  scsi_netlink.c  - SCSI Transport Netlink Interface
   4 *
   5 *  Copyright (C) 2006   James Smart, Emulex Corporation
   6 */
   7#include <linux/time.h>
   8#include <linux/jiffies.h>
   9#include <linux/security.h>
  10#include <linux/delay.h>
  11#include <linux/slab.h>
  12#include <linux/export.h>
  13#include <net/sock.h>
  14#include <net/netlink.h>
  15
  16#include <scsi/scsi_netlink.h>
  17#include "scsi_priv.h"
  18
  19struct sock *scsi_nl_sock = NULL;
  20EXPORT_SYMBOL_GPL(scsi_nl_sock);
  21
  22/**
  23 * scsi_nl_rcv_msg - Receive message handler.
  24 * @skb:                socket receive buffer
  25 *
  26 * Description: Extracts message from a receive buffer.
  27 *    Validates message header and calls appropriate transport message handler
  28 *
  29 *
  30 **/
  31static void
  32scsi_nl_rcv_msg(struct sk_buff *skb)
  33{
  34        struct nlmsghdr *nlh;
  35        struct scsi_nl_hdr *hdr;
  36        u32 rlen;
  37        int err, tport;
  38
  39        while (skb->len >= NLMSG_HDRLEN) {
  40                err = 0;
  41
  42                nlh = nlmsg_hdr(skb);
  43                if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) ||
  44                    (skb->len < nlh->nlmsg_len)) {
  45                        printk(KERN_WARNING "%s: discarding partial skb\n",
  46                                 __func__);
  47                        return;
  48                }
  49
  50                rlen = NLMSG_ALIGN(nlh->nlmsg_len);
  51                if (rlen > skb->len)
  52                        rlen = skb->len;
  53
  54                if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
  55                        err = -EBADMSG;
  56                        goto next_msg;
  57                }
  58
  59                hdr = nlmsg_data(nlh);
  60                if ((hdr->version != SCSI_NL_VERSION) ||
  61                    (hdr->magic != SCSI_NL_MAGIC)) {
  62                        err = -EPROTOTYPE;
  63                        goto next_msg;
  64                }
  65
  66                if (!netlink_capable(skb, CAP_SYS_ADMIN)) {
  67                        err = -EPERM;
  68                        goto next_msg;
  69                }
  70
  71                if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
  72                        printk(KERN_WARNING "%s: discarding partial message\n",
  73                                 __func__);
  74                        goto next_msg;
  75                }
  76
  77                /*
  78                 * Deliver message to the appropriate transport
  79                 */
  80                tport = hdr->transport;
  81                if (tport == SCSI_NL_TRANSPORT) {
  82                        switch (hdr->msgtype) {
  83                        case SCSI_NL_SHOST_VENDOR:
  84                                /* Locate the driver that corresponds to the message */
  85                                err = -ESRCH;
  86                                break;
  87                        default:
  88                                err = -EBADR;
  89                                break;
  90                        }
  91                        if (err)
  92                                printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
  93                                       __func__, hdr->msgtype, err);
  94                }
  95                else
  96                        err = -ENOENT;
  97
  98next_msg:
  99                if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
 100                        netlink_ack(skb, nlh, err, NULL);
 101
 102                skb_pull(skb, rlen);
 103        }
 104}
 105
 106/**
 107 * scsi_netlink_init - Called by SCSI subsystem to initialize
 108 *      the SCSI transport netlink interface
 109 *
 110 **/
 111void
 112scsi_netlink_init(void)
 113{
 114        struct netlink_kernel_cfg cfg = {
 115                .input  = scsi_nl_rcv_msg,
 116                .groups = SCSI_NL_GRP_CNT,
 117        };
 118
 119        scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
 120                                             &cfg);
 121        if (!scsi_nl_sock) {
 122                printk(KERN_ERR "%s: register of receive handler failed\n",
 123                                __func__);
 124                return;
 125        }
 126
 127        return;
 128}
 129
 130
 131/**
 132 * scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
 133 *
 134 **/
 135void
 136scsi_netlink_exit(void)
 137{
 138        if (scsi_nl_sock) {
 139                netlink_kernel_release(scsi_nl_sock);
 140        }
 141
 142        return;
 143}
 144
 145