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423 lines
9.0 KiB
423 lines
9.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Management Component Transport Protocol (MCTP) - device implementation. |
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* |
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* Copyright (c) 2021 Code Construct |
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* Copyright (c) 2021 Google |
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*/ |
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#include <linux/if_link.h> |
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#include <linux/mctp.h> |
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#include <linux/netdevice.h> |
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#include <linux/rcupdate.h> |
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#include <linux/rtnetlink.h> |
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#include <net/addrconf.h> |
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#include <net/netlink.h> |
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#include <net/mctp.h> |
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#include <net/mctpdevice.h> |
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#include <net/sock.h> |
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struct mctp_dump_cb { |
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int h; |
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int idx; |
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size_t a_idx; |
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}; |
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/* unlocked: caller must hold rcu_read_lock */ |
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struct mctp_dev *__mctp_dev_get(const struct net_device *dev) |
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{ |
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return rcu_dereference(dev->mctp_ptr); |
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} |
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struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev) |
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{ |
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return rtnl_dereference(dev->mctp_ptr); |
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} |
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static void mctp_dev_destroy(struct mctp_dev *mdev) |
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{ |
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struct net_device *dev = mdev->dev; |
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dev_put(dev); |
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kfree_rcu(mdev, rcu); |
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} |
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static int mctp_fill_addrinfo(struct sk_buff *skb, struct netlink_callback *cb, |
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struct mctp_dev *mdev, mctp_eid_t eid) |
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{ |
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struct ifaddrmsg *hdr; |
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struct nlmsghdr *nlh; |
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nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, |
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RTM_NEWADDR, sizeof(*hdr), NLM_F_MULTI); |
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if (!nlh) |
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return -EMSGSIZE; |
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hdr = nlmsg_data(nlh); |
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hdr->ifa_family = AF_MCTP; |
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hdr->ifa_prefixlen = 0; |
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hdr->ifa_flags = 0; |
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hdr->ifa_scope = 0; |
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hdr->ifa_index = mdev->dev->ifindex; |
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if (nla_put_u8(skb, IFA_LOCAL, eid)) |
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goto cancel; |
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if (nla_put_u8(skb, IFA_ADDRESS, eid)) |
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goto cancel; |
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nlmsg_end(skb, nlh); |
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return 0; |
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cancel: |
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nlmsg_cancel(skb, nlh); |
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return -EMSGSIZE; |
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} |
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static int mctp_dump_dev_addrinfo(struct mctp_dev *mdev, struct sk_buff *skb, |
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struct netlink_callback *cb) |
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{ |
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struct mctp_dump_cb *mcb = (void *)cb->ctx; |
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int rc = 0; |
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for (; mcb->a_idx < mdev->num_addrs; mcb->a_idx++) { |
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rc = mctp_fill_addrinfo(skb, cb, mdev, mdev->addrs[mcb->a_idx]); |
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if (rc < 0) |
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break; |
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} |
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return rc; |
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} |
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static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb) |
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{ |
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struct mctp_dump_cb *mcb = (void *)cb->ctx; |
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struct net *net = sock_net(skb->sk); |
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struct hlist_head *head; |
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struct net_device *dev; |
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struct ifaddrmsg *hdr; |
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struct mctp_dev *mdev; |
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int ifindex; |
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int idx, rc; |
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hdr = nlmsg_data(cb->nlh); |
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// filter by ifindex if requested |
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ifindex = hdr->ifa_index; |
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rcu_read_lock(); |
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for (; mcb->h < NETDEV_HASHENTRIES; mcb->h++, mcb->idx = 0) { |
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idx = 0; |
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head = &net->dev_index_head[mcb->h]; |
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hlist_for_each_entry_rcu(dev, head, index_hlist) { |
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if (idx >= mcb->idx && |
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(ifindex == 0 || ifindex == dev->ifindex)) { |
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mdev = __mctp_dev_get(dev); |
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if (mdev) { |
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rc = mctp_dump_dev_addrinfo(mdev, |
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skb, cb); |
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// Error indicates full buffer, this |
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// callback will get retried. |
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if (rc < 0) |
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goto out; |
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} |
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} |
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idx++; |
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// reset for next iteration |
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mcb->a_idx = 0; |
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} |
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} |
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out: |
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rcu_read_unlock(); |
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mcb->idx = idx; |
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return skb->len; |
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} |
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static const struct nla_policy ifa_mctp_policy[IFA_MAX + 1] = { |
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[IFA_ADDRESS] = { .type = NLA_U8 }, |
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[IFA_LOCAL] = { .type = NLA_U8 }, |
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}; |
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static int mctp_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, |
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struct netlink_ext_ack *extack) |
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{ |
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struct net *net = sock_net(skb->sk); |
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struct nlattr *tb[IFA_MAX + 1]; |
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struct net_device *dev; |
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struct mctp_addr *addr; |
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struct mctp_dev *mdev; |
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struct ifaddrmsg *ifm; |
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unsigned long flags; |
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u8 *tmp_addrs; |
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int rc; |
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rc = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_mctp_policy, |
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extack); |
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if (rc < 0) |
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return rc; |
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ifm = nlmsg_data(nlh); |
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if (tb[IFA_LOCAL]) |
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addr = nla_data(tb[IFA_LOCAL]); |
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else if (tb[IFA_ADDRESS]) |
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addr = nla_data(tb[IFA_ADDRESS]); |
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else |
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return -EINVAL; |
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/* find device */ |
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dev = __dev_get_by_index(net, ifm->ifa_index); |
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if (!dev) |
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return -ENODEV; |
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mdev = mctp_dev_get_rtnl(dev); |
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if (!mdev) |
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return -ENODEV; |
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if (!mctp_address_ok(addr->s_addr)) |
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return -EINVAL; |
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/* Prevent duplicates. Under RTNL so don't need to lock for reading */ |
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if (memchr(mdev->addrs, addr->s_addr, mdev->num_addrs)) |
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return -EEXIST; |
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tmp_addrs = kmalloc(mdev->num_addrs + 1, GFP_KERNEL); |
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if (!tmp_addrs) |
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return -ENOMEM; |
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memcpy(tmp_addrs, mdev->addrs, mdev->num_addrs); |
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tmp_addrs[mdev->num_addrs] = addr->s_addr; |
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/* Lock to write */ |
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spin_lock_irqsave(&mdev->addrs_lock, flags); |
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mdev->num_addrs++; |
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swap(mdev->addrs, tmp_addrs); |
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spin_unlock_irqrestore(&mdev->addrs_lock, flags); |
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kfree(tmp_addrs); |
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mctp_route_add_local(mdev, addr->s_addr); |
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return 0; |
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} |
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static int mctp_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, |
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struct netlink_ext_ack *extack) |
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{ |
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struct net *net = sock_net(skb->sk); |
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struct nlattr *tb[IFA_MAX + 1]; |
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struct net_device *dev; |
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struct mctp_addr *addr; |
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struct mctp_dev *mdev; |
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struct ifaddrmsg *ifm; |
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unsigned long flags; |
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u8 *pos; |
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int rc; |
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rc = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_mctp_policy, |
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extack); |
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if (rc < 0) |
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return rc; |
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ifm = nlmsg_data(nlh); |
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if (tb[IFA_LOCAL]) |
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addr = nla_data(tb[IFA_LOCAL]); |
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else if (tb[IFA_ADDRESS]) |
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addr = nla_data(tb[IFA_ADDRESS]); |
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else |
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return -EINVAL; |
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/* find device */ |
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dev = __dev_get_by_index(net, ifm->ifa_index); |
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if (!dev) |
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return -ENODEV; |
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mdev = mctp_dev_get_rtnl(dev); |
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if (!mdev) |
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return -ENODEV; |
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pos = memchr(mdev->addrs, addr->s_addr, mdev->num_addrs); |
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if (!pos) |
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return -ENOENT; |
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rc = mctp_route_remove_local(mdev, addr->s_addr); |
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// we can ignore -ENOENT in the case a route was already removed |
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if (rc < 0 && rc != -ENOENT) |
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return rc; |
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spin_lock_irqsave(&mdev->addrs_lock, flags); |
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memmove(pos, pos + 1, mdev->num_addrs - 1 - (pos - mdev->addrs)); |
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mdev->num_addrs--; |
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spin_unlock_irqrestore(&mdev->addrs_lock, flags); |
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return 0; |
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} |
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static struct mctp_dev *mctp_add_dev(struct net_device *dev) |
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{ |
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struct mctp_dev *mdev; |
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ASSERT_RTNL(); |
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mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); |
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if (!mdev) |
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return ERR_PTR(-ENOMEM); |
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spin_lock_init(&mdev->addrs_lock); |
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mdev->net = mctp_default_net(dev_net(dev)); |
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/* associate to net_device */ |
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rcu_assign_pointer(dev->mctp_ptr, mdev); |
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dev_hold(dev); |
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mdev->dev = dev; |
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return mdev; |
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} |
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static int mctp_fill_link_af(struct sk_buff *skb, |
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const struct net_device *dev, u32 ext_filter_mask) |
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{ |
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struct mctp_dev *mdev; |
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mdev = mctp_dev_get_rtnl(dev); |
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if (!mdev) |
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return -ENODATA; |
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if (nla_put_u32(skb, IFLA_MCTP_NET, mdev->net)) |
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return -EMSGSIZE; |
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return 0; |
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} |
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static size_t mctp_get_link_af_size(const struct net_device *dev, |
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u32 ext_filter_mask) |
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{ |
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struct mctp_dev *mdev; |
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unsigned int ret; |
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/* caller holds RCU */ |
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mdev = __mctp_dev_get(dev); |
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if (!mdev) |
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return 0; |
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ret = nla_total_size(4); /* IFLA_MCTP_NET */ |
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return ret; |
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} |
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static const struct nla_policy ifla_af_mctp_policy[IFLA_MCTP_MAX + 1] = { |
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[IFLA_MCTP_NET] = { .type = NLA_U32 }, |
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}; |
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static int mctp_set_link_af(struct net_device *dev, const struct nlattr *attr, |
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struct netlink_ext_ack *extack) |
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{ |
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struct nlattr *tb[IFLA_MCTP_MAX + 1]; |
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struct mctp_dev *mdev; |
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int rc; |
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rc = nla_parse_nested(tb, IFLA_MCTP_MAX, attr, ifla_af_mctp_policy, |
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NULL); |
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if (rc) |
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return rc; |
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mdev = mctp_dev_get_rtnl(dev); |
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if (!mdev) |
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return 0; |
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if (tb[IFLA_MCTP_NET]) |
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WRITE_ONCE(mdev->net, nla_get_u32(tb[IFLA_MCTP_NET])); |
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return 0; |
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} |
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static void mctp_unregister(struct net_device *dev) |
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{ |
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struct mctp_dev *mdev; |
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mdev = mctp_dev_get_rtnl(dev); |
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if (!mdev) |
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return; |
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RCU_INIT_POINTER(mdev->dev->mctp_ptr, NULL); |
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mctp_route_remove_dev(mdev); |
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mctp_neigh_remove_dev(mdev); |
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kfree(mdev->addrs); |
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mctp_dev_destroy(mdev); |
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} |
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static int mctp_register(struct net_device *dev) |
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{ |
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struct mctp_dev *mdev; |
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/* Already registered? */ |
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if (rtnl_dereference(dev->mctp_ptr)) |
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return 0; |
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/* only register specific types; MCTP-specific and loopback for now */ |
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if (dev->type != ARPHRD_MCTP && dev->type != ARPHRD_LOOPBACK) |
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return 0; |
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mdev = mctp_add_dev(dev); |
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if (IS_ERR(mdev)) |
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return PTR_ERR(mdev); |
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return 0; |
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} |
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static int mctp_dev_notify(struct notifier_block *this, unsigned long event, |
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void *ptr) |
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{ |
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struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
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int rc; |
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switch (event) { |
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case NETDEV_REGISTER: |
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rc = mctp_register(dev); |
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if (rc) |
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return notifier_from_errno(rc); |
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break; |
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case NETDEV_UNREGISTER: |
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mctp_unregister(dev); |
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break; |
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} |
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return NOTIFY_OK; |
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} |
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static struct rtnl_af_ops mctp_af_ops = { |
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.family = AF_MCTP, |
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.fill_link_af = mctp_fill_link_af, |
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.get_link_af_size = mctp_get_link_af_size, |
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.set_link_af = mctp_set_link_af, |
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}; |
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static struct notifier_block mctp_dev_nb = { |
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.notifier_call = mctp_dev_notify, |
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.priority = ADDRCONF_NOTIFY_PRIORITY, |
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}; |
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void __init mctp_device_init(void) |
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{ |
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register_netdevice_notifier(&mctp_dev_nb); |
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rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETADDR, |
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NULL, mctp_dump_addrinfo, 0); |
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rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWADDR, |
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mctp_rtm_newaddr, NULL, 0); |
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rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELADDR, |
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mctp_rtm_deladdr, NULL, 0); |
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rtnl_af_register(&mctp_af_ops); |
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} |
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void __exit mctp_device_exit(void) |
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{ |
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rtnl_af_unregister(&mctp_af_ops); |
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rtnl_unregister(PF_MCTP, RTM_DELADDR); |
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rtnl_unregister(PF_MCTP, RTM_NEWADDR); |
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rtnl_unregister(PF_MCTP, RTM_GETADDR); |
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unregister_netdevice_notifier(&mctp_dev_nb); |
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}
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