From dbcefdeb2a58039f4c81d0361056fbdd9be906a1 Mon Sep 17 00:00:00 2001 From: Matt Johnston Date: Mon, 20 Dec 2021 10:31:04 +0800 Subject: [PATCH] mctp: emit RTM_NEWADDR and RTM_DELADDR Userspace can receive notification of MCTP address changes via RTNLGRP_MCTP_IFADDR rtnetlink multicast group. Signed-off-by: Matt Johnston Link: https://lore.kernel.org/r/20211220023104.1965509-1-matt@codeconstruct.com.au Signed-off-by: Jakub Kicinski --- include/uapi/linux/rtnetlink.h | 2 ++ net/mctp/device.c | 53 ++++++++++++++++++++++++++++++++++++++---- 2 files changed, 50 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index 5888492..93d934c 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -754,6 +754,8 @@ enum rtnetlink_groups { #define RTNLGRP_NEXTHOP RTNLGRP_NEXTHOP RTNLGRP_BRVLAN, #define RTNLGRP_BRVLAN RTNLGRP_BRVLAN + RTNLGRP_MCTP_IFADDR, +#define RTNLGRP_MCTP_IFADDR RTNLGRP_MCTP_IFADDR __RTNLGRP_MAX }; #define RTNLGRP_MAX (__RTNLGRP_MAX - 1) diff --git a/net/mctp/device.c b/net/mctp/device.c index 8799ee7..ef2755f 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -35,14 +35,24 @@ struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev) return rtnl_dereference(dev->mctp_ptr); } -static int mctp_fill_addrinfo(struct sk_buff *skb, struct netlink_callback *cb, - struct mctp_dev *mdev, mctp_eid_t eid) +static int mctp_addrinfo_size(void) +{ + return NLMSG_ALIGN(sizeof(struct ifaddrmsg)) + + nla_total_size(1) // IFA_LOCAL + + nla_total_size(1) // IFA_ADDRESS + ; +} + +/* flag should be NLM_F_MULTI for dump calls */ +static int mctp_fill_addrinfo(struct sk_buff *skb, + struct mctp_dev *mdev, mctp_eid_t eid, + int msg_type, u32 portid, u32 seq, int flag) { struct ifaddrmsg *hdr; struct nlmsghdr *nlh; - nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, - RTM_NEWADDR, sizeof(*hdr), NLM_F_MULTI); + nlh = nlmsg_put(skb, portid, seq, + msg_type, sizeof(*hdr), flag); if (!nlh) return -EMSGSIZE; @@ -72,10 +82,14 @@ static int mctp_dump_dev_addrinfo(struct mctp_dev *mdev, struct sk_buff *skb, struct netlink_callback *cb) { struct mctp_dump_cb *mcb = (void *)cb->ctx; + u32 portid, seq; int rc = 0; + portid = NETLINK_CB(cb->skb).portid; + seq = cb->nlh->nlmsg_seq; for (; mcb->a_idx < mdev->num_addrs; mcb->a_idx++) { - rc = mctp_fill_addrinfo(skb, cb, mdev, mdev->addrs[mcb->a_idx]); + rc = mctp_fill_addrinfo(skb, mdev, mdev->addrs[mcb->a_idx], + RTM_NEWADDR, portid, seq, NLM_F_MULTI); if (rc < 0) break; } @@ -127,6 +141,32 @@ out: return skb->len; } +static void mctp_addr_notify(struct mctp_dev *mdev, mctp_eid_t eid, int msg_type, + struct sk_buff *req_skb, struct nlmsghdr *req_nlh) +{ + u32 portid = NETLINK_CB(req_skb).portid; + struct net *net = dev_net(mdev->dev); + struct sk_buff *skb; + int rc = -ENOBUFS; + + skb = nlmsg_new(mctp_addrinfo_size(), GFP_KERNEL); + if (!skb) + goto out; + + rc = mctp_fill_addrinfo(skb, mdev, eid, msg_type, + portid, req_nlh->nlmsg_seq, 0); + if (rc < 0) { + WARN_ON_ONCE(rc == -EMSGSIZE); + goto out; + } + + rtnl_notify(skb, net, portid, RTNLGRP_MCTP_IFADDR, req_nlh, GFP_KERNEL); + return; +out: + kfree_skb(skb); + rtnl_set_sk_err(net, RTNLGRP_MCTP_IFADDR, rc); +} + static const struct nla_policy ifa_mctp_policy[IFA_MAX + 1] = { [IFA_ADDRESS] = { .type = NLA_U8 }, [IFA_LOCAL] = { .type = NLA_U8 }, @@ -189,6 +229,7 @@ static int mctp_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, kfree(tmp_addrs); + mctp_addr_notify(mdev, addr->s_addr, RTM_NEWADDR, skb, nlh); mctp_route_add_local(mdev, addr->s_addr); return 0; @@ -244,6 +285,8 @@ static int mctp_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, mdev->num_addrs--; spin_unlock_irqrestore(&mdev->addrs_lock, flags); + mctp_addr_notify(mdev, addr->s_addr, RTM_DELADDR, skb, nlh); + return 0; } -- 2.7.4