From: Matt Johnston Date: Thu, 29 Jul 2021 02:20:48 +0000 (+0800) Subject: mctp: Add neighbour netlink interface X-Git-Tag: Ubuntu-5.15.0-12.12~1957^2~360^2~5 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=831119f8878173adbf31f1151adf0f4627c05e01;p=mirror_ubuntu-jammy-kernel.git mctp: Add neighbour netlink interface This change adds the netlink interfaces for manipulating the MCTP neighbour table. Signed-off-by: Matt Johnston Signed-off-by: David S. Miller --- diff --git a/net/mctp/neigh.c b/net/mctp/neigh.c index 8603f0c45a8f..90ed2f02d1fb 100644 --- a/net/mctp/neigh.c +++ b/net/mctp/neigh.c @@ -21,9 +21,9 @@ #include #include -static int __always_unused mctp_neigh_add(struct mctp_dev *mdev, mctp_eid_t eid, - enum mctp_neigh_source source, - size_t lladdr_len, const void *lladdr) +static int mctp_neigh_add(struct mctp_dev *mdev, mctp_eid_t eid, + enum mctp_neigh_source source, + size_t lladdr_len, const void *lladdr) { struct net *net = dev_net(mdev->dev); struct mctp_neigh *neigh; @@ -85,6 +85,196 @@ void mctp_neigh_remove_dev(struct mctp_dev *mdev) mutex_unlock(&net->mctp.neigh_lock); } +// TODO: add a "source" flag so netlink can only delete static neighbours? +static int mctp_neigh_remove(struct mctp_dev *mdev, mctp_eid_t eid) +{ + struct net *net = dev_net(mdev->dev); + struct mctp_neigh *neigh, *tmp; + bool dropped = false; + + mutex_lock(&net->mctp.neigh_lock); + list_for_each_entry_safe(neigh, tmp, &net->mctp.neighbours, list) { + if (neigh->dev == mdev && neigh->eid == eid) { + list_del_rcu(&neigh->list); + /* TODO: immediate RTM_DELNEIGH */ + call_rcu(&neigh->rcu, __mctp_neigh_free); + dropped = true; + } + } + + mutex_unlock(&net->mctp.neigh_lock); + return dropped ? 0 : -ENOENT; +} + +static const struct nla_policy nd_mctp_policy[NDA_MAX + 1] = { + [NDA_DST] = { .type = NLA_U8 }, + [NDA_LLADDR] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN }, +}; + +static int mctp_rtm_newneigh(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct net_device *dev; + struct mctp_dev *mdev; + struct ndmsg *ndm; + struct nlattr *tb[NDA_MAX + 1]; + int rc; + mctp_eid_t eid; + void *lladdr; + int lladdr_len; + + rc = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, nd_mctp_policy, + extack); + if (rc < 0) { + NL_SET_ERR_MSG(extack, "lladdr too large?"); + return rc; + } + + if (!tb[NDA_DST]) { + NL_SET_ERR_MSG(extack, "Neighbour EID must be specified"); + return -EINVAL; + } + + if (!tb[NDA_LLADDR]) { + NL_SET_ERR_MSG(extack, "Neighbour lladdr must be specified"); + return -EINVAL; + } + + eid = nla_get_u8(tb[NDA_DST]); + if (!mctp_address_ok(eid)) { + NL_SET_ERR_MSG(extack, "Invalid neighbour EID"); + return -EINVAL; + } + + lladdr = nla_data(tb[NDA_LLADDR]); + lladdr_len = nla_len(tb[NDA_LLADDR]); + + ndm = nlmsg_data(nlh); + + dev = __dev_get_by_index(net, ndm->ndm_ifindex); + if (!dev) + return -ENODEV; + + mdev = mctp_dev_get_rtnl(dev); + if (!mdev) + return -ENODEV; + + if (lladdr_len != dev->addr_len) { + NL_SET_ERR_MSG(extack, "Wrong lladdr length"); + return -EINVAL; + } + + return mctp_neigh_add(mdev, eid, MCTP_NEIGH_STATIC, + lladdr_len, lladdr); +} + +static int mctp_rtm_delneigh(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct nlattr *tb[NDA_MAX + 1]; + struct net_device *dev; + struct mctp_dev *mdev; + struct ndmsg *ndm; + int rc; + mctp_eid_t eid; + + rc = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, nd_mctp_policy, + extack); + if (rc < 0) { + NL_SET_ERR_MSG(extack, "incorrect format"); + return rc; + } + + if (!tb[NDA_DST]) { + NL_SET_ERR_MSG(extack, "Neighbour EID must be specified"); + return -EINVAL; + } + eid = nla_get_u8(tb[NDA_DST]); + + ndm = nlmsg_data(nlh); + dev = __dev_get_by_index(net, ndm->ndm_ifindex); + if (!dev) + return -ENODEV; + + mdev = mctp_dev_get_rtnl(dev); + if (!mdev) + return -ENODEV; + + return mctp_neigh_remove(mdev, eid); +} + +static int mctp_fill_neigh(struct sk_buff *skb, u32 portid, u32 seq, int event, + unsigned int flags, struct mctp_neigh *neigh) +{ + struct net_device *dev = neigh->dev->dev; + struct nlmsghdr *nlh; + struct ndmsg *hdr; + + nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags); + if (!nlh) + return -EMSGSIZE; + + hdr = nlmsg_data(nlh); + hdr->ndm_family = AF_MCTP; + hdr->ndm_ifindex = dev->ifindex; + hdr->ndm_state = 0; // TODO other state bits? + if (neigh->source == MCTP_NEIGH_STATIC) + hdr->ndm_state |= NUD_PERMANENT; + hdr->ndm_flags = 0; + hdr->ndm_type = RTN_UNICAST; // TODO: is loopback RTN_LOCAL? + + if (nla_put_u8(skb, NDA_DST, neigh->eid)) + goto cancel; + + if (nla_put(skb, NDA_LLADDR, dev->addr_len, neigh->ha)) + goto cancel; + + nlmsg_end(skb, nlh); + + return 0; +cancel: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static int mctp_rtm_getneigh(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + int rc, idx, req_ifindex; + struct mctp_neigh *neigh; + struct ndmsg *ndmsg; + struct { + int idx; + } *cbctx = (void *)cb->ctx; + + ndmsg = nlmsg_data(cb->nlh); + req_ifindex = ndmsg->ndm_ifindex; + + idx = 0; + rcu_read_lock(); + list_for_each_entry_rcu(neigh, &net->mctp.neighbours, list) { + if (idx < cbctx->idx) + goto cont; + + rc = 0; + if (req_ifindex == 0 || req_ifindex == neigh->dev->dev->ifindex) + rc = mctp_fill_neigh(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + RTM_NEWNEIGH, NLM_F_MULTI, neigh); + + if (rc) + break; +cont: + idx++; + } + rcu_read_unlock(); + + cbctx->idx = idx; + return skb->len; +} + int mctp_neigh_lookup(struct mctp_dev *mdev, mctp_eid_t eid, void *ret_hwaddr) { struct net *net = dev_net(mdev->dev); @@ -111,6 +301,7 @@ static int __net_init mctp_neigh_net_init(struct net *net) struct netns_mctp *ns = &net->mctp; INIT_LIST_HEAD(&ns->neighbours); + mutex_init(&ns->neigh_lock); return 0; } @@ -132,10 +323,20 @@ static struct pernet_operations mctp_net_ops = { int __init mctp_neigh_init(void) { + rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWNEIGH, + mctp_rtm_newneigh, NULL, 0); + rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELNEIGH, + mctp_rtm_delneigh, NULL, 0); + rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETNEIGH, + NULL, mctp_rtm_getneigh, 0); + return register_pernet_subsys(&mctp_net_ops); } void __exit mctp_neigh_exit(void) { unregister_pernet_subsys(&mctp_net_ops); + rtnl_unregister(PF_MCTP, RTM_GETNEIGH); + rtnl_unregister(PF_MCTP, RTM_DELNEIGH); + rtnl_unregister(PF_MCTP, RTM_NEWNEIGH); }