From 5b861f6baa3a22a48d7a4ad0ce38a223d36c978a Mon Sep 17 00:00:00 2001 From: Girish Moodalbail Date: Thu, 20 Jul 2017 22:44:20 -0700 Subject: [PATCH] geneve: add rtnl changelink support This patch adds changelink rtnl operation support for geneve devices and the code changes involve: - added geneve_quiesce() which quiesces the geneve device data path for both TX and RX. This lets us perform the changelink operation atomically w.r.t data path. Also added geneve_unquiesce() to reverse the operation of geneve_quiesce(). - refactor geneve_newlink into geneve_nl2info to be used by both geneve_newlink and geneve_changelink - geneve_nl2info takes a changelink boolean argument to isolate changelink checks. - Allow changing only a few attributes (ttl, tos, and remote tunnel endpoint IP address (within the same address family)): - return -EOPNOTSUPP for attributes that cannot be changed for now. Incremental patches can make the non-supported one available in the future if needed. Signed-off-by: Girish Moodalbail Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- drivers/net/geneve.c | 218 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 176 insertions(+), 42 deletions(-) diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index de8156c6b292..0436a4283059 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -715,6 +715,7 @@ free_dst: static struct rtable *geneve_get_v4_rt(struct sk_buff *skb, struct net_device *dev, + struct geneve_sock *gs4, struct flowi4 *fl4, const struct ip_tunnel_info *info) { @@ -724,7 +725,7 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb, struct rtable *rt = NULL; __u8 tos; - if (!rcu_dereference(geneve->sock4)) + if (!gs4) return ERR_PTR(-EIO); memset(fl4, 0, sizeof(*fl4)); @@ -764,6 +765,7 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb, #if IS_ENABLED(CONFIG_IPV6) static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb, struct net_device *dev, + struct geneve_sock *gs6, struct flowi6 *fl6, const struct ip_tunnel_info *info) { @@ -771,10 +773,8 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb, struct geneve_dev *geneve = netdev_priv(dev); struct dst_entry *dst = NULL; struct dst_cache *dst_cache; - struct geneve_sock *gs6; __u8 prio; - gs6 = rcu_dereference(geneve->sock6); if (!gs6) return ERR_PTR(-EIO); @@ -827,7 +827,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev, __be16 df; int err; - rt = geneve_get_v4_rt(skb, dev, &fl4, info); + rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info); if (IS_ERR(rt)) return PTR_ERR(rt); @@ -866,7 +866,7 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev, __be16 sport; int err; - dst = geneve_get_v6_dst(skb, dev, &fl6, info); + dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info); if (IS_ERR(dst)) return PTR_ERR(dst); @@ -951,8 +951,9 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) if (ip_tunnel_info_af(info) == AF_INET) { struct rtable *rt; struct flowi4 fl4; + struct geneve_sock *gs4 = rcu_dereference(geneve->sock4); - rt = geneve_get_v4_rt(skb, dev, &fl4, info); + rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info); if (IS_ERR(rt)) return PTR_ERR(rt); @@ -962,8 +963,9 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) } else if (ip_tunnel_info_af(info) == AF_INET6) { struct dst_entry *dst; struct flowi6 fl6; + struct geneve_sock *gs6 = rcu_dereference(geneve->sock6); - dst = geneve_get_v6_dst(skb, dev, &fl6, info); + dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info); if (IS_ERR(dst)) return PTR_ERR(dst); @@ -1140,6 +1142,15 @@ static bool is_tnl_info_zero(const struct ip_tunnel_info *info) return true; } +static bool geneve_dst_addr_equal(struct ip_tunnel_info *a, + struct ip_tunnel_info *b) +{ + if (ip_tunnel_info_af(a) == AF_INET) + return a->key.u.ipv4.dst == b->key.u.ipv4.dst; + else + return ipv6_addr_equal(&a->key.u.ipv6.dst, &b->key.u.ipv6.dst); +} + static int geneve_configure(struct net *net, struct net_device *dev, const struct ip_tunnel_info *info, bool metadata, bool ipv6_rx_csum) @@ -1197,24 +1208,22 @@ static void init_tnl_info(struct ip_tunnel_info *info, __u16 dst_port) info->key.tp_dst = htons(dst_port); } -static int geneve_newlink(struct net *net, struct net_device *dev, - struct nlattr *tb[], struct nlattr *data[], - struct netlink_ext_ack *extack) +static int geneve_nl2info(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], struct ip_tunnel_info *info, + bool *metadata, bool *use_udp6_rx_checksums, + bool changelink) { - bool use_udp6_rx_checksums = false; - struct ip_tunnel_info info; - bool metadata = false; - - init_tnl_info(&info, GENEVE_UDP_PORT); - if (data[IFLA_GENEVE_REMOTE] && data[IFLA_GENEVE_REMOTE6]) return -EINVAL; if (data[IFLA_GENEVE_REMOTE]) { - info.key.u.ipv4.dst = + if (changelink && (ip_tunnel_info_af(info) == AF_INET6)) + return -EOPNOTSUPP; + + info->key.u.ipv4.dst = nla_get_in_addr(data[IFLA_GENEVE_REMOTE]); - if (IN_MULTICAST(ntohl(info.key.u.ipv4.dst))) { + if (IN_MULTICAST(ntohl(info->key.u.ipv4.dst))) { netdev_dbg(dev, "multicast remote is unsupported\n"); return -EINVAL; } @@ -1222,21 +1231,24 @@ static int geneve_newlink(struct net *net, struct net_device *dev, if (data[IFLA_GENEVE_REMOTE6]) { #if IS_ENABLED(CONFIG_IPV6) - info.mode = IP_TUNNEL_INFO_IPV6; - info.key.u.ipv6.dst = + if (changelink && (ip_tunnel_info_af(info) == AF_INET)) + return -EOPNOTSUPP; + + info->mode = IP_TUNNEL_INFO_IPV6; + info->key.u.ipv6.dst = nla_get_in6_addr(data[IFLA_GENEVE_REMOTE6]); - if (ipv6_addr_type(&info.key.u.ipv6.dst) & + if (ipv6_addr_type(&info->key.u.ipv6.dst) & IPV6_ADDR_LINKLOCAL) { netdev_dbg(dev, "link-local remote is unsupported\n"); return -EINVAL; } - if (ipv6_addr_is_multicast(&info.key.u.ipv6.dst)) { + if (ipv6_addr_is_multicast(&info->key.u.ipv6.dst)) { netdev_dbg(dev, "multicast remote is unsupported\n"); return -EINVAL; } - info.key.tun_flags |= TUNNEL_CSUM; - use_udp6_rx_checksums = true; + info->key.tun_flags |= TUNNEL_CSUM; + *use_udp6_rx_checksums = true; #else return -EPFNOSUPPORT; #endif @@ -1245,48 +1257,169 @@ static int geneve_newlink(struct net *net, struct net_device *dev, if (data[IFLA_GENEVE_ID]) { __u32 vni; __u8 tvni[3]; + __be64 tunid; vni = nla_get_u32(data[IFLA_GENEVE_ID]); tvni[0] = (vni & 0x00ff0000) >> 16; tvni[1] = (vni & 0x0000ff00) >> 8; tvni[2] = vni & 0x000000ff; - info.key.tun_id = vni_to_tunnel_id(tvni); + tunid = vni_to_tunnel_id(tvni); + if (changelink && (tunid != info->key.tun_id)) + return -EOPNOTSUPP; + info->key.tun_id = tunid; } + if (data[IFLA_GENEVE_TTL]) - info.key.ttl = nla_get_u8(data[IFLA_GENEVE_TTL]); + info->key.ttl = nla_get_u8(data[IFLA_GENEVE_TTL]); if (data[IFLA_GENEVE_TOS]) - info.key.tos = nla_get_u8(data[IFLA_GENEVE_TOS]); + info->key.tos = nla_get_u8(data[IFLA_GENEVE_TOS]); if (data[IFLA_GENEVE_LABEL]) { - info.key.label = nla_get_be32(data[IFLA_GENEVE_LABEL]) & + info->key.label = nla_get_be32(data[IFLA_GENEVE_LABEL]) & IPV6_FLOWLABEL_MASK; - if (info.key.label && (!(info.mode & IP_TUNNEL_INFO_IPV6))) + if (info->key.label && (!(info->mode & IP_TUNNEL_INFO_IPV6))) return -EINVAL; } - if (data[IFLA_GENEVE_PORT]) - info.key.tp_dst = nla_get_be16(data[IFLA_GENEVE_PORT]); + if (data[IFLA_GENEVE_PORT]) { + if (changelink) + return -EOPNOTSUPP; + info->key.tp_dst = nla_get_be16(data[IFLA_GENEVE_PORT]); + } - if (data[IFLA_GENEVE_COLLECT_METADATA]) - metadata = true; + if (data[IFLA_GENEVE_COLLECT_METADATA]) { + if (changelink) + return -EOPNOTSUPP; + *metadata = true; + } - if (data[IFLA_GENEVE_UDP_CSUM] && - nla_get_u8(data[IFLA_GENEVE_UDP_CSUM])) - info.key.tun_flags |= TUNNEL_CSUM; + if (data[IFLA_GENEVE_UDP_CSUM]) { + if (changelink) + return -EOPNOTSUPP; + if (nla_get_u8(data[IFLA_GENEVE_UDP_CSUM])) + info->key.tun_flags |= TUNNEL_CSUM; + } - if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX] && - nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX])) - info.key.tun_flags &= ~TUNNEL_CSUM; + if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]) { + if (changelink) + return -EOPNOTSUPP; + if (nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX])) + info->key.tun_flags &= ~TUNNEL_CSUM; + } - if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX] && - nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX])) - use_udp6_rx_checksums = false; + if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]) { + if (changelink) + return -EOPNOTSUPP; + if (nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX])) + *use_udp6_rx_checksums = false; + } + + return 0; +} + +static int geneve_newlink(struct net *net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + bool use_udp6_rx_checksums = false; + struct ip_tunnel_info info; + bool metadata = false; + int err; + + init_tnl_info(&info, GENEVE_UDP_PORT); + err = geneve_nl2info(dev, tb, data, &info, &metadata, + &use_udp6_rx_checksums, false); + if (err) + return err; return geneve_configure(net, dev, &info, metadata, use_udp6_rx_checksums); } +/* Quiesces the geneve device data path for both TX and RX. + * + * On transmit geneve checks for non-NULL geneve_sock before it proceeds. + * So, if we set that socket to NULL under RCU and wait for synchronize_net() + * to complete for the existing set of in-flight packets to be transmitted, + * then we would have quiesced the transmit data path. All the future packets + * will get dropped until we unquiesce the data path. + * + * On receive geneve dereference the geneve_sock stashed in the socket. So, + * if we set that to NULL under RCU and wait for synchronize_net() to + * complete, then we would have quiesced the receive data path. + */ +static void geneve_quiesce(struct geneve_dev *geneve, struct geneve_sock **gs4, + struct geneve_sock **gs6) +{ + *gs4 = rtnl_dereference(geneve->sock4); + rcu_assign_pointer(geneve->sock4, NULL); + if (*gs4) + rcu_assign_sk_user_data((*gs4)->sock->sk, NULL); +#if IS_ENABLED(CONFIG_IPV6) + *gs6 = rtnl_dereference(geneve->sock6); + rcu_assign_pointer(geneve->sock6, NULL); + if (*gs6) + rcu_assign_sk_user_data((*gs6)->sock->sk, NULL); +#else + *gs6 = NULL; +#endif + synchronize_net(); +} + +/* Resumes the geneve device data path for both TX and RX. */ +static void geneve_unquiesce(struct geneve_dev *geneve, struct geneve_sock *gs4, + struct geneve_sock __maybe_unused *gs6) +{ + rcu_assign_pointer(geneve->sock4, gs4); + if (gs4) + rcu_assign_sk_user_data(gs4->sock->sk, gs4); +#if IS_ENABLED(CONFIG_IPV6) + rcu_assign_pointer(geneve->sock6, gs6); + if (gs6) + rcu_assign_sk_user_data(gs6->sock->sk, gs6); +#endif + synchronize_net(); +} + +static int geneve_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct geneve_dev *geneve = netdev_priv(dev); + struct geneve_sock *gs4, *gs6; + struct ip_tunnel_info info; + bool metadata; + bool use_udp6_rx_checksums; + int err; + + /* If the geneve device is configured for metadata (or externally + * controlled, for example, OVS), then nothing can be changed. + */ + if (geneve->collect_md) + return -EOPNOTSUPP; + + /* Start with the existing info. */ + memcpy(&info, &geneve->info, sizeof(info)); + metadata = geneve->collect_md; + use_udp6_rx_checksums = geneve->use_udp6_rx_checksums; + err = geneve_nl2info(dev, tb, data, &info, &metadata, + &use_udp6_rx_checksums, true); + if (err) + return err; + + if (!geneve_dst_addr_equal(&geneve->info, &info)) + dst_cache_reset(&info.dst_cache); + + geneve_quiesce(geneve, &gs4, &gs6); + geneve->info = info; + geneve->collect_md = metadata; + geneve->use_udp6_rx_checksums = use_udp6_rx_checksums; + geneve_unquiesce(geneve, gs4, gs6); + + return 0; +} + static void geneve_dellink(struct net_device *dev, struct list_head *head) { struct geneve_dev *geneve = netdev_priv(dev); @@ -1375,6 +1508,7 @@ static struct rtnl_link_ops geneve_link_ops __read_mostly = { .setup = geneve_setup, .validate = geneve_validate, .newlink = geneve_newlink, + .changelink = geneve_changelink, .dellink = geneve_dellink, .get_size = geneve_get_size, .fill_info = geneve_fill_info, -- 2.20.1