From 2e15ea390e6f4466655066d97e22ec66870a042c Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Fri, 7 Aug 2015 23:51:42 -0700 Subject: [PATCH] ip_gre: Add support to collect tunnel metadata. Following patch create new tunnel flag which enable tunnel metadata collection on given device. Signed-off-by: Pravin B Shelar Acked-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/ip_tunnels.h | 7 +- include/uapi/linux/if_tunnel.h | 1 + net/ipv4/ip_gre.c | 195 ++++++++++++++++++++++++++++++--- net/ipv4/ip_tunnel.c | 37 +++++-- net/ipv4/ipip.c | 2 +- net/ipv6/sit.c | 2 +- 6 files changed, 216 insertions(+), 28 deletions(-) diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 47984415f5d1..984dbfa15e13 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -82,6 +82,8 @@ struct ip_tunnel_dst { __be32 saddr; }; +struct metadata_dst; + struct ip_tunnel { struct ip_tunnel __rcu *next; struct hlist_node hash_node; @@ -115,6 +117,7 @@ struct ip_tunnel { unsigned int prl_count; /* # of entries in PRL */ int ip_tnl_net_id; struct gro_cells gro_cells; + bool collect_md; }; #define TUNNEL_CSUM __cpu_to_be16(0x01) @@ -149,6 +152,7 @@ struct tnl_ptk_info { struct ip_tunnel_net { struct net_device *fb_tunnel_dev; struct hlist_head tunnels[IP_TNL_HASH_SIZE]; + struct ip_tunnel __rcu *collect_md_tun; }; struct ip_tunnel_encap_ops { @@ -235,7 +239,8 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, __be32 key); int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, - const struct tnl_ptk_info *tpi, bool log_ecn_error); + const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, + bool log_ecn_error); int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], struct ip_tunnel_parm *p); int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h index bd3cc11a431f..af4de90ba27d 100644 --- a/include/uapi/linux/if_tunnel.h +++ b/include/uapi/linux/if_tunnel.h @@ -112,6 +112,7 @@ enum { IFLA_GRE_ENCAP_FLAGS, IFLA_GRE_ENCAP_SPORT, IFLA_GRE_ENCAP_DPORT, + IFLA_GRE_COLLECT_METADATA, __IFLA_GRE_MAX, }; diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 5fd706473c73..554a760c2cd0 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -47,6 +48,7 @@ #include #include #include +#include #if IS_ENABLED(CONFIG_IPV6) #include @@ -200,9 +202,29 @@ static int ipgre_err(struct sk_buff *skb, u32 info, return PACKET_RCVD; } +static __be64 key_to_tunnel_id(__be32 key) +{ +#ifdef __BIG_ENDIAN + return (__force __be64)((__force u32)key); +#else + return (__force __be64)((__force u64)key << 32); +#endif +} + +/* Returns the least-significant 32 bits of a __be64. */ +static __be32 tunnel_id_to_key(__be64 x) +{ +#ifdef __BIG_ENDIAN + return (__force __be32)x; +#else + return (__force __be32)((__force u64)x >> 32); +#endif +} + static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) { struct net *net = dev_net(skb->dev); + struct metadata_dst *tun_dst = NULL; struct ip_tunnel_net *itn; const struct iphdr *iph; struct ip_tunnel *tunnel; @@ -218,40 +240,162 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) if (tunnel) { skb_pop_mac_header(skb); - ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error); + if (tunnel->collect_md) { + struct ip_tunnel_info *info; + + tun_dst = metadata_dst_alloc(0, GFP_ATOMIC); + if (!tun_dst) + return PACKET_REJECT; + + info = &tun_dst->u.tun_info; + info->key.ipv4_src = iph->saddr; + info->key.ipv4_dst = iph->daddr; + info->key.ipv4_tos = iph->tos; + info->key.ipv4_ttl = iph->ttl; + + info->mode = IP_TUNNEL_INFO_RX; + info->key.tun_flags = tpi->flags & + (TUNNEL_CSUM | TUNNEL_KEY); + info->key.tun_id = key_to_tunnel_id(tpi->key); + + info->key.tp_src = 0; + info->key.tp_dst = 0; + } + + ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); return PACKET_RCVD; } return PACKET_REJECT; } +static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags, + __be16 proto, __be32 key, __be32 seq) +{ + struct gre_base_hdr *greh; + + skb_push(skb, hdr_len); + + skb_reset_transport_header(skb); + greh = (struct gre_base_hdr *)skb->data; + greh->flags = tnl_flags_to_gre_flags(flags); + greh->protocol = proto; + + if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { + __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); + + if (flags & TUNNEL_SEQ) { + *ptr = seq; + ptr--; + } + if (flags & TUNNEL_KEY) { + *ptr = key; + ptr--; + } + if (flags & TUNNEL_CSUM && + !(skb_shinfo(skb)->gso_type & + (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) { + *ptr = 0; + *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0, + skb->len, 0)); + } + } +} + static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, const struct iphdr *tnl_params, __be16 proto) { struct ip_tunnel *tunnel = netdev_priv(dev); - struct tnl_ptk_info tpi; - tpi.flags = tunnel->parms.o_flags; - tpi.proto = proto; - tpi.key = tunnel->parms.o_key; if (tunnel->parms.o_flags & TUNNEL_SEQ) tunnel->o_seqno++; - tpi.seq = htonl(tunnel->o_seqno); /* Push GRE header. */ - gre_build_header(skb, &tpi, tunnel->tun_hlen); - - skb_set_inner_protocol(skb, tpi.proto); + build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags, + proto, tunnel->parms.o_key, htonl(tunnel->o_seqno)); + skb_set_inner_protocol(skb, proto); ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); } +static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_tunnel_info *tun_info; + struct net *net = dev_net(dev); + const struct ip_tunnel_key *key; + struct flowi4 fl; + struct rtable *rt; + int min_headroom; + int tunnel_hlen; + __be16 df, flags; + int err; + + tun_info = skb_tunnel_info(skb, AF_INET); + if (unlikely(!tun_info || tun_info->mode != IP_TUNNEL_INFO_TX)) + goto err_free_skb; + + key = &tun_info->key; + memset(&fl, 0, sizeof(fl)); + fl.daddr = key->ipv4_dst; + fl.saddr = key->ipv4_src; + fl.flowi4_tos = RT_TOS(key->ipv4_tos); + fl.flowi4_mark = skb->mark; + fl.flowi4_proto = IPPROTO_GRE; + + rt = ip_route_output_key(net, &fl); + if (IS_ERR(rt)) + goto err_free_skb; + + tunnel_hlen = ip_gre_calc_hlen(key->tun_flags); + + min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len + + tunnel_hlen + sizeof(struct iphdr); + if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) { + int head_delta = SKB_DATA_ALIGN(min_headroom - + skb_headroom(skb) + + 16); + err = pskb_expand_head(skb, max_t(int, head_delta, 0), + 0, GFP_ATOMIC); + if (unlikely(err)) + goto err_free_rt; + } + + /* Push Tunnel header. */ + skb = gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)); + if (IS_ERR(skb)) { + skb = NULL; + goto err_free_rt; + } + + flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY); + build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB), + tunnel_id_to_key(tun_info->key.tun_id), 0); + + df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; + err = iptunnel_xmit(skb->sk, rt, skb, fl.saddr, + key->ipv4_dst, IPPROTO_GRE, + key->ipv4_tos, key->ipv4_ttl, df, false); + iptunnel_xmit_stats(err, &dev->stats, dev->tstats); + return; + +err_free_rt: + ip_rt_put(rt); +err_free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; +} + static netdev_tx_t ipgre_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *tnl_params; + if (tunnel->collect_md) { + gre_fb_xmit(skb, dev); + return NETDEV_TX_OK; + } + if (dev->header_ops) { /* Need space for new headers */ if (skb_cow_head(skb, dev->needed_headroom - @@ -277,7 +421,6 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb, goto out; __gre_xmit(skb, dev, tnl_params, skb->protocol); - return NETDEV_TX_OK; free_skb: @@ -292,6 +435,11 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, { struct ip_tunnel *tunnel = netdev_priv(dev); + if (tunnel->collect_md) { + gre_fb_xmit(skb, dev); + return NETDEV_TX_OK; + } + skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); if (IS_ERR(skb)) goto out; @@ -300,7 +448,6 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, goto free_skb; __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); - return NETDEV_TX_OK; free_skb: @@ -596,8 +743,10 @@ static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[]) return ipgre_tunnel_validate(tb, data); } -static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], - struct ip_tunnel_parm *parms) +static void ipgre_netlink_parms(struct net_device *dev, + struct nlattr *data[], + struct nlattr *tb[], + struct ip_tunnel_parm *parms) { memset(parms, 0, sizeof(*parms)); @@ -635,6 +784,12 @@ static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) parms->iph.frag_off = htons(IP_DF); + + if (data[IFLA_GRE_COLLECT_METADATA]) { + struct ip_tunnel *t = netdev_priv(dev); + + t->collect_md = true; + } } /* This function returns true when ENCAP attributes are present in the nl msg */ @@ -712,7 +867,7 @@ static int ipgre_newlink(struct net *src_net, struct net_device *dev, return err; } - ipgre_netlink_parms(data, tb, &p); + ipgre_netlink_parms(dev, data, tb, &p); return ip_tunnel_newlink(dev, tb, &p); } @@ -730,7 +885,7 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], return err; } - ipgre_netlink_parms(data, tb, &p); + ipgre_netlink_parms(dev, data, tb, &p); return ip_tunnel_changelink(dev, tb, &p); } @@ -765,6 +920,8 @@ static size_t ipgre_get_size(const struct net_device *dev) nla_total_size(2) + /* IFLA_GRE_ENCAP_DPORT */ nla_total_size(2) + + /* IFLA_GRE_COLLECT_METADATA */ + nla_total_size(0) + 0; } @@ -796,6 +953,11 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) t->encap.flags)) goto nla_put_failure; + if (t->collect_md) { + if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) + goto nla_put_failure; + } + return 0; nla_put_failure: @@ -817,6 +979,7 @@ static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, + [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, }; static struct rtnl_link_ops ipgre_link_ops __read_mostly = { @@ -851,7 +1014,7 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { static int __net_init ipgre_tap_init_net(struct net *net) { - return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL); + return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); } static void __net_exit ipgre_tap_exit_net(struct net *net) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 626d9e56a6bd..cbb51f3fac06 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -230,10 +230,13 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, if (cand) return cand; + t = rcu_dereference(itn->collect_md_tun); + if (t) + return t; + if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP) return netdev_priv(itn->fb_tunnel_dev); - return NULL; } EXPORT_SYMBOL_GPL(ip_tunnel_lookup); @@ -261,11 +264,15 @@ static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t) { struct hlist_head *head = ip_bucket(itn, &t->parms); + if (t->collect_md) + rcu_assign_pointer(itn->collect_md_tun, t); hlist_add_head_rcu(&t->hash_node, head); } -static void ip_tunnel_del(struct ip_tunnel *t) +static void ip_tunnel_del(struct ip_tunnel_net *itn, struct ip_tunnel *t) { + if (t->collect_md) + rcu_assign_pointer(itn->collect_md_tun, NULL); hlist_del_init_rcu(&t->hash_node); } @@ -419,7 +426,8 @@ static struct ip_tunnel *ip_tunnel_create(struct net *net, } int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, - const struct tnl_ptk_info *tpi, bool log_ecn_error) + const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, + bool log_ecn_error) { struct pcpu_sw_netstats *tstats; const struct iphdr *iph = ip_hdr(skb); @@ -478,6 +486,9 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, skb->dev = tunnel->dev; } + if (tun_dst) + skb_dst_set(skb, (struct dst_entry *)tun_dst); + gro_cells_receive(&tunnel->gro_cells, skb); return 0; @@ -806,7 +817,7 @@ static void ip_tunnel_update(struct ip_tunnel_net *itn, struct ip_tunnel_parm *p, bool set_mtu) { - ip_tunnel_del(t); + ip_tunnel_del(itn, t); t->parms.iph.saddr = p->iph.saddr; t->parms.iph.daddr = p->iph.daddr; t->parms.i_key = p->i_key; @@ -967,7 +978,7 @@ void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); if (itn->fb_tunnel_dev != dev) { - ip_tunnel_del(netdev_priv(dev)); + ip_tunnel_del(itn, netdev_priv(dev)); unregister_netdevice_queue(dev, head); } } @@ -1072,8 +1083,13 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], nt = netdev_priv(dev); itn = net_generic(net, nt->ip_tnl_net_id); - if (ip_tunnel_find(itn, p, dev->type)) - return -EEXIST; + if (nt->collect_md) { + if (rtnl_dereference(itn->collect_md_tun)) + return -EEXIST; + } else { + if (ip_tunnel_find(itn, p, dev->type)) + return -EEXIST; + } nt->net = net; nt->parms = *p; @@ -1089,7 +1105,6 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], dev->mtu = mtu; ip_tunnel_add(itn, nt); - out: return err; } @@ -1163,6 +1178,10 @@ int ip_tunnel_init(struct net_device *dev) iph->version = 4; iph->ihl = 5; + if (tunnel->collect_md) { + dev->features |= NETIF_F_NETNS_LOCAL; + netif_keep_dst(dev); + } return 0; } EXPORT_SYMBOL_GPL(ip_tunnel_init); @@ -1176,7 +1195,7 @@ void ip_tunnel_uninit(struct net_device *dev) itn = net_generic(net, tunnel->ip_tnl_net_id); /* fb_tunnel_dev will be unregisted in net-exit call. */ if (itn->fb_tunnel_dev != dev) - ip_tunnel_del(netdev_priv(dev)); + ip_tunnel_del(itn, netdev_priv(dev)); ip_tunnel_dst_reset_all(tunnel); } diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c index 254238daf58b..f34c31defafe 100644 --- a/net/ipv4/ipip.c +++ b/net/ipv4/ipip.c @@ -198,7 +198,7 @@ static int ipip_rcv(struct sk_buff *skb) goto drop; if (iptunnel_pull_header(skb, 0, tpi.proto)) goto drop; - return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); + return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, log_ecn_error); } return -1; diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index ac35a28599be..94428fd85b2f 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -742,7 +742,7 @@ static int ipip_rcv(struct sk_buff *skb) goto drop; if (iptunnel_pull_header(skb, 0, tpi.proto)) goto drop; - return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); + return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, log_ecn_error); } return 1;