From 5138e86f176055e8194bf30fa2e05bc839ce1a1f Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Tue, 4 Apr 2017 09:23:41 -0400 Subject: [PATCH 1/2] rtnetlink: Convert rtnetlink_event to white list The rtnetlink_event currently functions as a blacklist where we block cerntain netdev events from being sent to user space. As a result, events have been added to the system that userspace probably doesn't care about. This patch converts the implementation to the white list so that newly events would have to be specifically added to the list to be sent to userspace. This would force new event implementers to consider whether a given event is usefull to user space or if it's just a kernel event. Signed-off-by: Vladislav Yasevich Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9c3947a43eff8..58419da7961bf 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4116,22 +4116,25 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi struct net_device *dev = netdev_notifier_info_to_dev(ptr); switch (event) { - case NETDEV_UP: - case NETDEV_DOWN: - case NETDEV_PRE_UP: - case NETDEV_POST_INIT: - case NETDEV_REGISTER: - case NETDEV_CHANGE: - case NETDEV_PRE_TYPE_CHANGE: - case NETDEV_GOING_DOWN: - case NETDEV_UNREGISTER: - case NETDEV_UNREGISTER_FINAL: - case NETDEV_RELEASE: - case NETDEV_JOIN: - case NETDEV_BONDING_INFO: + case NETDEV_REBOOT: + case NETDEV_CHANGEMTU: + case NETDEV_CHANGEADDR: + case NETDEV_CHANGENAME: + case NETDEV_FEAT_CHANGE: + case NETDEV_BONDING_FAILOVER: + case NETDEV_POST_TYPE_CHANGE: + case NETDEV_NOTIFY_PEERS: + case NETDEV_CHANGEUPPER: + case NETDEV_RESEND_IGMP: + case NETDEV_PRECHANGEMTU: + case NETDEV_CHANGEINFODATA: + case NETDEV_PRECHANGEUPPER: + case NETDEV_CHANGELOWERSTATE: + case NETDEV_UDP_TUNNEL_PUSH_INFO: + case NETDEV_CHANGE_TX_QUEUE_LEN: + rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL); break; default: - rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL); break; } return NOTIFY_DONE; From def12888c161e6fec0702e5ec9c3962846e3a21d Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Tue, 4 Apr 2017 09:23:42 -0400 Subject: [PATCH 2/2] rtnl: Add support for netdev event to link messages When netdev events happen, a rtnetlink_event() handler will send messages for every event in it's white list. These messages contain current information about a particular device, but they do not include the iformation about which event just happened. The consumer of the message has to try to infer this information. In some cases (ex: NETDEV_NOTIFY_PEERS), that is not possible. This patch adds a new extension to RTM_NEWLINK message called IFLA_EVENT that would have an encoding of the which event triggered this message. This would allow the the message consumer to easily determine if it is interested in a particular event or not. Signed-off-by: Vladislav Yasevich Signed-off-by: David S. Miller --- include/linux/rtnetlink.h | 3 +- include/uapi/linux/if_link.h | 21 ++++++++ net/core/dev.c | 2 +- net/core/rtnetlink.c | 92 ++++++++++++++++++++++++++++++++---- 4 files changed, 107 insertions(+), 11 deletions(-) diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 57e54847b0b9e..0459018173cff 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -18,7 +18,8 @@ extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags); struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev, - unsigned change, gfp_t flags); + unsigned change, unsigned long event, + gfp_t flags); void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags); diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h index 8b405afb23763..97f6d302f6278 100644 --- a/include/uapi/linux/if_link.h +++ b/include/uapi/linux/if_link.h @@ -157,6 +157,7 @@ enum { IFLA_GSO_MAX_SIZE, IFLA_PAD, IFLA_XDP, + IFLA_EVENT, __IFLA_MAX }; @@ -899,4 +900,24 @@ enum { #define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1) +enum { + IFLA_EVENT_UNSPEC, + IFLA_EVENT_REBOOT, + IFLA_EVENT_CHANGE_MTU, + IFLA_EVENT_CHANGE_ADDR, + IFLA_EVENT_CHANGE_NAME, + IFLA_EVENT_FEAT_CHANGE, + IFLA_EVENT_BONDING_FAILOVER, + IFLA_EVENT_POST_TYPE_CHANGE, + IFLA_EVENT_NOTIFY_PEERS, + IFLA_EVENT_CHANGE_UPPER, + IFLA_EVENT_RESEND_IGMP, + IFLA_EVENT_PRE_CHANGE_MTU, + IFLA_EVENT_CHANGE_INFO_DATA, + IFLA_EVENT_PRE_CHANGE_UPPER, + IFLA_EVENT_CHANGE_LOWER_STATE, + IFLA_EVENT_UDP_TUNNEL_PUSH_INFO, + IFLA_EVENT_CHANGE_TX_QUEUE_LEN, +}; + #endif /* _UAPI_LINUX_IF_LINK_H */ diff --git a/net/core/dev.c b/net/core/dev.c index ef9fe60ee294b..7efb4178ffef7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6840,7 +6840,7 @@ static void rollback_registered_many(struct list_head *head) if (!dev->rtnl_link_ops || dev->rtnl_link_state == RTNL_LINK_INITIALIZED) - skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, + skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0, GFP_KERNEL); /* diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 58419da7961bf..b2bd4c9ee8600 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -944,6 +944,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */ + nla_total_size(IFNAMSIZ) /* IFLA_PHYS_PORT_NAME */ + rtnl_xdp_size(dev) /* IFLA_XDP */ + + nla_total_size(4) /* IFLA_EVENT */ + nla_total_size(1); /* IFLA_PROTO_DOWN */ } @@ -1276,9 +1277,70 @@ static int rtnl_xdp_fill(struct sk_buff *skb, struct net_device *dev) return err; } +static int rtnl_fill_link_event(struct sk_buff *skb, unsigned long event) +{ + u32 rtnl_event; + + switch (event) { + case NETDEV_REBOOT: + rtnl_event = IFLA_EVENT_REBOOT; + break; + case NETDEV_CHANGEMTU: + rtnl_event = IFLA_EVENT_CHANGE_MTU; + break; + case NETDEV_CHANGEADDR: + rtnl_event = IFLA_EVENT_CHANGE_ADDR; + break; + case NETDEV_CHANGENAME: + rtnl_event = IFLA_EVENT_CHANGE_NAME; + break; + case NETDEV_FEAT_CHANGE: + rtnl_event = IFLA_EVENT_FEAT_CHANGE; + break; + case NETDEV_BONDING_FAILOVER: + rtnl_event = IFLA_EVENT_BONDING_FAILOVER; + break; + case NETDEV_POST_TYPE_CHANGE: + rtnl_event = IFLA_EVENT_POST_TYPE_CHANGE; + break; + case NETDEV_NOTIFY_PEERS: + rtnl_event = IFLA_EVENT_NOTIFY_PEERS; + break; + case NETDEV_CHANGEUPPER: + rtnl_event = IFLA_EVENT_CHANGE_UPPER; + break; + case NETDEV_RESEND_IGMP: + rtnl_event = IFLA_EVENT_RESEND_IGMP; + break; + case NETDEV_PRECHANGEMTU: + rtnl_event = IFLA_EVENT_PRE_CHANGE_MTU; + break; + case NETDEV_CHANGEINFODATA: + rtnl_event = IFLA_EVENT_CHANGE_INFO_DATA; + break; + case NETDEV_PRECHANGEUPPER: + rtnl_event = IFLA_EVENT_PRE_CHANGE_UPPER; + break; + case NETDEV_CHANGELOWERSTATE: + rtnl_event = IFLA_EVENT_CHANGE_LOWER_STATE; + break; + case NETDEV_UDP_TUNNEL_PUSH_INFO: + rtnl_event = IFLA_EVENT_UDP_TUNNEL_PUSH_INFO; + break; + case NETDEV_CHANGE_TX_QUEUE_LEN: + rtnl_event = IFLA_EVENT_CHANGE_TX_QUEUE_LEN; + break; + default: + return 0; + } + + return nla_put_u32(skb, IFLA_EVENT, rtnl_event); +} + static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, int type, u32 pid, u32 seq, u32 change, - unsigned int flags, u32 ext_filter_mask) + unsigned int flags, u32 ext_filter_mask, + unsigned long event) { struct ifinfomsg *ifm; struct nlmsghdr *nlh; @@ -1327,6 +1389,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down)) goto nla_put_failure; + if (rtnl_fill_link_event(skb, event)) + goto nla_put_failure; + if (rtnl_fill_link_ifmap(skb, dev)) goto nla_put_failure; @@ -1461,6 +1526,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_LINK_NETNSID] = { .type = NLA_S32 }, [IFLA_PROTO_DOWN] = { .type = NLA_U8 }, [IFLA_XDP] = { .type = NLA_NESTED }, + [IFLA_EVENT] = { .type = NLA_U32 }, }; static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { @@ -1619,7 +1685,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 0, flags, - ext_filter_mask); + ext_filter_mask, 0); /* If we ran out of room on the first message, * we're in trouble */ @@ -2710,7 +2776,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh) return -ENOBUFS; err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid, - nlh->nlmsg_seq, 0, 0, ext_filter_mask); + nlh->nlmsg_seq, 0, 0, ext_filter_mask, 0); if (err < 0) { /* -EMSGSIZE implies BUG in if_nlmsg_size */ WARN_ON(err == -EMSGSIZE); @@ -2782,7 +2848,8 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) } struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev, - unsigned int change, gfp_t flags) + unsigned int change, + unsigned long event, gfp_t flags) { struct net *net = dev_net(dev); struct sk_buff *skb; @@ -2793,7 +2860,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev, if (skb == NULL) goto errout; - err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0, 0); + err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0, 0, event); if (err < 0) { /* -EMSGSIZE implies BUG in if_nlmsg_size() */ WARN_ON(err == -EMSGSIZE); @@ -2814,18 +2881,25 @@ void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags) rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, flags); } -void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change, - gfp_t flags) +static void rtmsg_ifinfo_event(int type, struct net_device *dev, + unsigned int change, unsigned long event, + gfp_t flags) { struct sk_buff *skb; if (dev->reg_state != NETREG_REGISTERED) return; - skb = rtmsg_ifinfo_build_skb(type, dev, change, flags); + skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags); if (skb) rtmsg_ifinfo_send(skb, dev, flags); } + +void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change, + gfp_t flags) +{ + rtmsg_ifinfo_event(type, dev, change, 0, flags); +} EXPORT_SYMBOL(rtmsg_ifinfo); static int nlmsg_populate_fdb_fill(struct sk_buff *skb, @@ -4132,7 +4206,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi case NETDEV_CHANGELOWERSTATE: case NETDEV_UDP_TUNNEL_PUSH_INFO: case NETDEV_CHANGE_TX_QUEUE_LEN: - rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL); + rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, event, GFP_KERNEL); break; default: break;