diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 00d26d919459422eb0cc0da039e152dd271c8832..56db1efd7189ac6b25fdfc4a18b579f28e01a4b7 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1215,14 +1215,20 @@ flowlabel_consistency - BOOLEAN FALSE: disabled Default: TRUE -auto_flowlabels - BOOLEAN - Automatically generate flow labels based based on a flow hash - of the packet. This allows intermediate devices, such as routers, - to idenfify packet flows for mechanisms like Equal Cost Multipath +auto_flowlabels - INTEGER + Automatically generate flow labels based on a flow hash of the + packet. This allows intermediate devices, such as routers, to + identify packet flows for mechanisms like Equal Cost Multipath Routing (see RFC 6438). - TRUE: enabled - FALSE: disabled - Default: false + 0: automatic flow labels are completely disabled + 1: automatic flow labels are enabled by default, they can be + disabled on a per socket basis using the IPV6_AUTOFLOWLABEL + socket option + 2: automatic flow labels are allowed, they may be enabled on a + per socket basis using the IPV6_AUTOFLOWLABEL socket option + 3: automatic flow labels are enabled and enforced, they cannot + be disabled by the socket option + Default: 1 flowlabel_state_ranges - BOOLEAN Split the flow label number space into two ranges. 0-0x7FFFF is diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 648a2c2419930dd8f5784d58cad738774fcd927b..b7c1286e247d9c50951ad8d9d1256ccc9d691481 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -37,6 +37,7 @@ #include #include #include +#include /* A. Checksumming of received packets by device. * @@ -945,6 +946,26 @@ static inline __u32 skb_get_hash(struct sk_buff *skb) return skb->hash; } +__u32 __skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6); + +static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6) +{ + if (!skb->l4_hash && !skb->sw_hash) + __skb_get_hash_flowi6(skb, fl6); + + return skb->hash; +} + +__u32 __skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl); + +static inline __u32 skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl4) +{ + if (!skb->l4_hash && !skb->sw_hash) + __skb_get_hash_flowi4(skb, fl4); + + return skb->hash; +} + __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb); static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) diff --git a/include/net/ipv6.h b/include/net/ipv6.h index eecdfc92f8070b388b5907f00fc33359f2126eae..711cca428cc8cd56b40de704265ad73262a6d2a4 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -707,35 +707,69 @@ static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow, } #if IS_ENABLED(CONFIG_IPV6) + +/* Sysctl settings for net ipv6.auto_flowlabels */ +#define IP6_AUTO_FLOW_LABEL_OFF 0 +#define IP6_AUTO_FLOW_LABEL_OPTOUT 1 +#define IP6_AUTO_FLOW_LABEL_OPTIN 2 +#define IP6_AUTO_FLOW_LABEL_FORCED 3 + +#define IP6_AUTO_FLOW_LABEL_MAX IP6_AUTO_FLOW_LABEL_FORCED + +#define IP6_DEFAULT_AUTO_FLOW_LABELS IP6_AUTO_FLOW_LABEL_OPTOUT + static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb, - __be32 flowlabel, bool autolabel) + __be32 flowlabel, bool autolabel, + struct flowi6 *fl6) { - if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) { - u32 hash; + u32 hash; - hash = skb_get_hash(skb); + if (flowlabel || + net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF || + (!autolabel && + net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED)) + return flowlabel; - /* Since this is being sent on the wire obfuscate hash a bit - * to minimize possbility that any useful information to an - * attacker is leaked. Only lower 20 bits are relevant. - */ - hash ^= hash >> 12; + hash = skb_get_hash_flowi6(skb, fl6); - flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK; + /* Since this is being sent on the wire obfuscate hash a bit + * to minimize possbility that any useful information to an + * attacker is leaked. Only lower 20 bits are relevant. + */ + rol32(hash, 16); - if (net->ipv6.sysctl.flowlabel_state_ranges) - flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG; - } + flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK; + + if (net->ipv6.sysctl.flowlabel_state_ranges) + flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG; return flowlabel; } + +static inline int ip6_default_np_autolabel(struct net *net) +{ + switch (net->ipv6.sysctl.auto_flowlabels) { + case IP6_AUTO_FLOW_LABEL_OFF: + case IP6_AUTO_FLOW_LABEL_OPTIN: + default: + return 0; + case IP6_AUTO_FLOW_LABEL_OPTOUT: + case IP6_AUTO_FLOW_LABEL_FORCED: + return 1; + } +} #else static inline void ip6_set_txhash(struct sock *sk) { } static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb, - __be32 flowlabel, bool autolabel) + __be32 flowlabel, bool autolabel, + struct flowi6 *fl6) { return flowlabel; } +static inline int ip6_default_np_autolabel(struct net *net) +{ + return 0; +} #endif diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 2a834c6179b9973e45274d793e7d744939e5f49e..11e6540fa386918fe207b2e72e45b60d35ddb963 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -590,6 +590,15 @@ void make_flow_keys_digest(struct flow_keys_digest *digest, } EXPORT_SYMBOL(make_flow_keys_digest); +static inline void __skb_set_sw_hash(struct sk_buff *skb, u32 hash, + struct flow_keys *keys) +{ + if (keys->ports.ports) + skb->l4_hash = 1; + skb->sw_hash = 1; + skb->hash = hash; +} + /** * __skb_get_hash: calculate a flow hash * @skb: sk_buff to calculate flow hash from @@ -609,10 +618,8 @@ void __skb_get_hash(struct sk_buff *skb) hash = ___skb_get_hash(skb, &keys, hashrnd); if (!hash) return; - if (keys.ports.ports) - skb->l4_hash = 1; - skb->sw_hash = 1; - skb->hash = hash; + + __skb_set_sw_hash(skb, hash, &keys); } EXPORT_SYMBOL(__skb_get_hash); @@ -624,6 +631,49 @@ __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb) } EXPORT_SYMBOL(skb_get_hash_perturb); +__u32 __skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6) +{ + struct flow_keys keys; + + memset(&keys, 0, sizeof(keys)); + + memcpy(&keys.addrs.v6addrs.src, &fl6->saddr, + sizeof(keys.addrs.v6addrs.src)); + memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr, + sizeof(keys.addrs.v6addrs.dst)); + keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; + keys.ports.src = fl6->fl6_sport; + keys.ports.dst = fl6->fl6_dport; + keys.keyid.keyid = fl6->fl6_gre_key; + keys.tags.flow_label = (__force u32)fl6->flowlabel; + keys.basic.ip_proto = fl6->flowi6_proto; + + __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), &keys); + + return skb->hash; +} +EXPORT_SYMBOL(__skb_get_hash_flowi6); + +__u32 __skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl4) +{ + struct flow_keys keys; + + memset(&keys, 0, sizeof(keys)); + + keys.addrs.v4addrs.src = fl4->saddr; + keys.addrs.v4addrs.dst = fl4->daddr; + keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + keys.ports.src = fl4->fl4_sport; + keys.ports.dst = fl4->fl4_dport; + keys.keyid.keyid = fl4->fl4_gre_key; + keys.basic.ip_proto = fl4->flowi4_proto; + + __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), &keys); + + return skb->hash; +} +EXPORT_SYMBOL(__skb_get_hash_flowi4); + u32 __skb_get_poff(const struct sk_buff *skb, void *data, const struct flow_keys *keys, int hlen) { diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 7bc92ea4ae8fd17701f65aaa1a3063a3912ba259..44bb66bde0e2d97308c3c68a8d6b225ce04d08a8 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -197,6 +197,7 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol, np->mcast_hops = IPV6_DEFAULT_MCASTHOPS; np->mc_loop = 1; np->pmtudisc = IPV6_PMTUDISC_WANT; + np->autoflowlabel = ip6_default_np_autolabel(sock_net(sk)); sk->sk_ipv6only = net->ipv6.sysctl.bindv6only; /* Init the ipv4 part of the socket since we can have sockets @@ -767,10 +768,10 @@ static int __net_init inet6_net_init(struct net *net) net->ipv6.sysctl.bindv6only = 0; net->ipv6.sysctl.icmpv6_time = 1*HZ; net->ipv6.sysctl.flowlabel_consistency = 1; - net->ipv6.sysctl.auto_flowlabels = 0; + net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS; net->ipv6.sysctl.idgen_retries = 3; net->ipv6.sysctl.idgen_delay = 1 * HZ; - net->ipv6.sysctl.flowlabel_state_ranges = 1; + net->ipv6.sysctl.flowlabel_state_ranges = 0; atomic_set(&net->ipv6.fib6_sernum, 1); err = ipv6_init_mibs(net); diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index a38d3ac0f18f6e631e3a17904bf617f7a0dfe28a..34f121812a1484e0ff23ea337ee39f35424a9628 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -728,7 +728,7 @@ static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb, */ ipv6h = ipv6_hdr(skb); ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), - ip6_make_flowlabel(net, skb, fl6->flowlabel, false)); + ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6)); ipv6h->hop_limit = tunnel->parms.hop_limit; ipv6h->nexthdr = proto; ipv6h->saddr = fl6->saddr; @@ -1182,7 +1182,8 @@ static int ip6gre_header(struct sk_buff *skb, struct net_device *dev, ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb, - t->fl.u.ip6.flowlabel, false)); + t->fl.u.ip6.flowlabel, true, + &t->fl.u.ip6)); ipv6h->hop_limit = t->parms.hop_limit; ipv6h->nexthdr = NEXTHDR_GRE; ipv6h->saddr = t->parms.laddr; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 92b7cf0dc1f95ea7251bd0b40dbd4b2218ae743c..26ea4793074004d0af1026bb378860b53baa0ad2 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -207,7 +207,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, hlimit = ip6_dst_hoplimit(dst); ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, - np->autoflowlabel)); + np->autoflowlabel, fl6)); hdr->payload_len = htons(seg_len); hdr->nexthdr = proto; @@ -1649,7 +1649,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk, ip6_flow_hdr(hdr, v6_cork->tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, - np->autoflowlabel)); + np->autoflowlabel, fl6)); hdr->hop_limit = v6_cork->hop_limit; hdr->nexthdr = proto; hdr->saddr = fl6->saddr; diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 2e67b660118bf7eeaf2f08033aa759190dea0c3a..b0ab420612bcc30efd5e58a30bdfb5e730e88b0e 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1095,7 +1095,7 @@ static int ip6_tnl_xmit2(struct sk_buff *skb, skb_reset_network_header(skb); ipv6h = ipv6_hdr(skb); ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), - ip6_make_flowlabel(net, skb, fl6->flowlabel, false)); + ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6)); ipv6h->hop_limit = t->parms.hop_limit; ipv6h->nexthdr = proto; ipv6h->saddr = fl6->saddr; diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index db48aebd9c470c2d3a40c7a4250b67887250985e..45243bbe52536d523a7aff0b636a72b8f2e3daf5 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -17,6 +17,9 @@ #include static int one = 1; +static int auto_flowlabels_min; +static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX; + static struct ctl_table ipv6_table_template[] = { { @@ -45,7 +48,9 @@ static struct ctl_table ipv6_table_template[] = { .data = &init_net.ipv6.sysctl.auto_flowlabels, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &auto_flowlabels_min, + .extra2 = &auto_flowlabels_max }, { .procname = "fwmark_reflect",