diff options
Diffstat (limited to 'net/ipv4')
33 files changed, 1534 insertions, 343 deletions
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig index 50d6a9b..300b068 100644 --- a/net/ipv4/Kconfig +++ b/net/ipv4/Kconfig @@ -640,6 +640,21 @@ config TCP_CONG_CDG D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg +config TCP_CONG_BBR + tristate "BBR TCP" + default n + ---help--- + + BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to + maximize network utilization and minimize queues. It builds an explicit + model of the the bottleneck delivery rate and path round-trip + propagation delay. It tolerates packet loss and delay unrelated to + congestion. It can operate over LAN, WAN, cellular, wifi, or cable + modem links. It can coexist with flows that use loss-based congestion + control, and can operate with shallow buffers, deep buffers, + bufferbloat, policers, or AQM schemes that do not provide a delay + signal. It requires the fq ("Fair Queue") pacing packet scheduler. + choice prompt "Default TCP congestion control" default DEFAULT_CUBIC @@ -674,6 +689,9 @@ choice config DEFAULT_CDG bool "CDG" if TCP_CONG_CDG=y + config DEFAULT_BBR + bool "BBR" if TCP_CONG_BBR=y + config DEFAULT_RENO bool "Reno" endchoice diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index 24629b6..bc6a6c8 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -8,7 +8,7 @@ obj-y := route.o inetpeer.o protocol.o \ inet_timewait_sock.o inet_connection_sock.o \ tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \ tcp_minisocks.o tcp_cong.o tcp_metrics.o tcp_fastopen.o \ - tcp_recovery.o \ + tcp_rate.o tcp_recovery.o \ tcp_offload.o datagram.o raw.o udp.o udplite.o \ udp_offload.o arp.o icmp.o devinet.o af_inet.o igmp.o \ fib_frontend.o fib_semantics.o fib_trie.o \ @@ -41,6 +41,7 @@ obj-$(CONFIG_INET_DIAG) += inet_diag.o obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o obj-$(CONFIG_INET_UDP_DIAG) += udp_diag.o obj-$(CONFIG_NET_TCPPROBE) += tcp_probe.o +obj-$(CONFIG_TCP_CONG_BBR) += tcp_bbr.o obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o obj-$(CONFIG_TCP_CONG_CDG) += tcp_cdg.o obj-$(CONFIG_TCP_CONG_CUBIC) += tcp_cubic.o diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index e94b47b..1effc98 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1192,7 +1192,7 @@ EXPORT_SYMBOL(inet_sk_rebuild_header); struct sk_buff *inet_gso_segment(struct sk_buff *skb, netdev_features_t features) { - bool udpfrag = false, fixedid = false, encap; + bool udpfrag = false, fixedid = false, gso_partial, encap; struct sk_buff *segs = ERR_PTR(-EINVAL); const struct net_offload *ops; unsigned int offset = 0; @@ -1245,6 +1245,8 @@ struct sk_buff *inet_gso_segment(struct sk_buff *skb, if (IS_ERR_OR_NULL(segs)) goto out; + gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); + skb = segs; do { iph = (struct iphdr *)(skb_mac_header(skb) + nhoff); @@ -1259,9 +1261,13 @@ struct sk_buff *inet_gso_segment(struct sk_buff *skb, iph->id = htons(id); id += skb_shinfo(skb)->gso_segs; } - tot_len = skb_shinfo(skb)->gso_size + - SKB_GSO_CB(skb)->data_offset + - skb->head - (unsigned char *)iph; + + if (gso_partial) + tot_len = skb_shinfo(skb)->gso_size + + SKB_GSO_CB(skb)->data_offset + + skb->head - (unsigned char *)iph; + else + tot_len = skb->len - nhoff; } else { if (!fixedid) iph->id = htons(id++); diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 4e56a4c..c3b8047 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -182,26 +182,13 @@ static void fib_flush(struct net *net) struct fib_table *tb; hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) - flushed += fib_table_flush(tb); + flushed += fib_table_flush(net, tb); } if (flushed) rt_cache_flush(net); } -void fib_flush_external(struct net *net) -{ - struct fib_table *tb; - struct hlist_head *head; - unsigned int h; - - for (h = 0; h < FIB_TABLE_HASHSZ; h++) { - head = &net->ipv4.fib_table_hash[h]; - hlist_for_each_entry(tb, head, tb_hlist) - fib_table_flush_external(tb); - } -} - /* * Find address type as if only "dev" was present in the system. If * on_dev is NULL then all interfaces are taken into consideration. @@ -590,13 +577,13 @@ int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) if (cmd == SIOCDELRT) { tb = fib_get_table(net, cfg.fc_table); if (tb) - err = fib_table_delete(tb, &cfg); + err = fib_table_delete(net, tb, &cfg); else err = -ESRCH; } else { tb = fib_new_table(net, cfg.fc_table); if (tb) - err = fib_table_insert(tb, &cfg); + err = fib_table_insert(net, tb, &cfg); else err = -ENOBUFS; } @@ -719,7 +706,7 @@ static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) goto errout; } - err = fib_table_delete(tb, &cfg); + err = fib_table_delete(net, tb, &cfg); errout: return err; } @@ -741,7 +728,7 @@ static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) goto errout; } - err = fib_table_insert(tb, &cfg); + err = fib_table_insert(net, tb, &cfg); errout: return err; } @@ -828,9 +815,9 @@ static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifad cfg.fc_scope = RT_SCOPE_HOST; if (cmd == RTM_NEWROUTE) - fib_table_insert(tb, &cfg); + fib_table_insert(net, tb, &cfg); else - fib_table_delete(tb, &cfg); + fib_table_delete(net, tb, &cfg); } void fib_add_ifaddr(struct in_ifaddr *ifa) @@ -1254,7 +1241,7 @@ static void ip_fib_net_exit(struct net *net) hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { hlist_del(&tb->tb_hlist); - fib_table_flush(tb); + fib_table_flush(net, tb); fib_free_table(tb); } } diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c index 770bebe..2e50062 100644 --- a/net/ipv4/fib_rules.c +++ b/net/ipv4/fib_rules.c @@ -164,6 +164,14 @@ static struct fib_table *fib_empty_table(struct net *net) return NULL; } +static int call_fib_rule_notifiers(struct net *net, + enum fib_event_type event_type) +{ + struct fib_notifier_info info; + + return call_fib_notifiers(net, event_type, &info); +} + static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { FRA_GENERIC_POLICY, [FRA_FLOW] = { .type = NLA_U32 }, @@ -220,7 +228,7 @@ static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, rule4->tos = frh->tos; net->ipv4.fib_has_custom_rules = true; - fib_flush_external(rule->fr_net); + call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD); err = 0; errout: @@ -242,7 +250,7 @@ static int fib4_rule_delete(struct fib_rule *rule) net->ipv4.fib_num_tclassid_users--; #endif net->ipv4.fib_has_custom_rules = true; - fib_flush_external(rule->fr_net); + call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL); errout: return err; } diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 241f27b..31cef36 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -73,6 +73,7 @@ #include <linux/slab.h> #include <linux/export.h> #include <linux/vmalloc.h> +#include <linux/notifier.h> #include <net/net_namespace.h> #include <net/ip.h> #include <net/protocol.h> @@ -80,10 +81,47 @@ #include <net/tcp.h> #include <net/sock.h> #include <net/ip_fib.h> -#include <net/switchdev.h> #include <trace/events/fib.h> #include "fib_lookup.h" +static BLOCKING_NOTIFIER_HEAD(fib_chain); + +int register_fib_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&fib_chain, nb); +} +EXPORT_SYMBOL(register_fib_notifier); + +int unregister_fib_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&fib_chain, nb); +} +EXPORT_SYMBOL(unregister_fib_notifier); + +int call_fib_notifiers(struct net *net, enum fib_event_type event_type, + struct fib_notifier_info *info) +{ + info->net = net; + return blocking_notifier_call_chain(&fib_chain, event_type, info); +} + +static int call_fib_entry_notifiers(struct net *net, + enum fib_event_type event_type, u32 dst, + int dst_len, struct fib_info *fi, + u8 tos, u8 type, u32 tb_id, u32 nlflags) +{ + struct fib_entry_notifier_info info = { + .dst = dst, + .dst_len = dst_len, + .fi = fi, + .tos = tos, + .type = type, + .tb_id = tb_id, + .nlflags = nlflags, + }; + return call_fib_notifiers(net, event_type, &info.info); +} + #define MAX_STAT_DEPTH 32 #define KEYLENGTH (8*sizeof(t_key)) @@ -1076,7 +1114,8 @@ static int fib_insert_alias(struct trie *t, struct key_vector *tp, } /* Caller must hold RTNL. */ -int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) +int fib_table_insert(struct net *net, struct fib_table *tb, + struct fib_config *cfg) { struct trie *t = (struct trie *)tb->tb_data; struct fib_alias *fa, *new_fa; @@ -1175,17 +1214,6 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) new_fa->tb_id = tb->tb_id; new_fa->fa_default = -1; - err = switchdev_fib_ipv4_add(key, plen, fi, - new_fa->fa_tos, - cfg->fc_type, - cfg->fc_nlflags, - tb->tb_id); - if (err) { - switchdev_fib_ipv4_abort(fi); - kmem_cache_free(fn_alias_kmem, new_fa); - goto out; - } - hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); alias_free_mem_rcu(fa); @@ -1193,6 +1221,11 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) fib_release_info(fi_drop); if (state & FA_S_ACCESSED) rt_cache_flush(cfg->fc_nlinfo.nl_net); + + call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, + key, plen, fi, + new_fa->fa_tos, cfg->fc_type, + tb->tb_id, cfg->fc_nlflags); rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id, &cfg->fc_nlinfo, nlflags); @@ -1228,30 +1261,22 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) new_fa->tb_id = tb->tb_id; new_fa->fa_default = -1; - /* (Optionally) offload fib entry to switch hardware. */ - err = switchdev_fib_ipv4_add(key, plen, fi, tos, cfg->fc_type, - cfg->fc_nlflags, tb->tb_id); - if (err) { - switchdev_fib_ipv4_abort(fi); - goto out_free_new_fa; - } - /* Insert new entry to the list. */ err = fib_insert_alias(t, tp, l, new_fa, fa, key); if (err) - goto out_sw_fib_del; + goto out_free_new_fa; if (!plen) tb->tb_num_default++; rt_cache_flush(cfg->fc_nlinfo.nl_net); + call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, key, plen, fi, tos, + cfg->fc_type, tb->tb_id, cfg->fc_nlflags); rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, &cfg->fc_nlinfo, nlflags); succeeded: return 0; -out_sw_fib_del: - switchdev_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id); out_free_new_fa: kmem_cache_free(fn_alias_kmem, new_fa); out: @@ -1490,7 +1515,8 @@ static void fib_remove_alias(struct trie *t, struct key_vector *tp, } /* Caller must hold RTNL. */ -int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) +int fib_table_delete(struct net *net, struct fib_table *tb, + struct fib_config *cfg) { struct trie *t = (struct trie *) tb->tb_data; struct fib_alias *fa, *fa_to_delete; @@ -1543,9 +1569,9 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) if (!fa_to_delete) return -ESRCH; - switchdev_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos, - cfg->fc_type, tb->tb_id); - + call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen, + fa_to_delete->fa_info, tos, cfg->fc_type, + tb->tb_id, 0); rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, &cfg->fc_nlinfo, 0); @@ -1734,82 +1760,8 @@ out: return NULL; } -/* Caller must hold RTNL */ -void fib_table_flush_external(struct fib_table *tb) -{ - struct trie *t = (struct trie *)tb->tb_data; - struct key_vector *pn = t->kv; - unsigned long cindex = 1; - struct hlist_node *tmp; - struct fib_alias *fa; - - /* walk trie in reverse order */ - for (;;) { - unsigned char slen = 0; - struct key_vector *n; - - if (!(cindex--)) { - t_key pkey = pn->key; - - /* cannot resize the trie vector */ - if (IS_TRIE(pn)) - break; - - /* resize completed node */ - pn = resize(t, pn); - cindex = get_index(pkey, pn); - - continue; - } - - /* grab the next available node */ - n = get_child(pn, cindex); - if (!n) - continue; - - if (IS_TNODE(n)) { - /* record pn and cindex for leaf walking */ - pn = n; - cindex = 1ul << n->bits; - - continue; - } - - hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { - struct fib_info *fi = fa->fa_info; - - /* if alias was cloned to local then we just - * need to remove the local copy from main - */ - if (tb->tb_id != fa->tb_id) { - hlist_del_rcu(&fa->fa_list); - alias_free_mem_rcu(fa); - continue; - } - - /* record local slen */ - slen = fa->fa_slen; - - if (!fi || !(fi->fib_flags & RTNH_F_OFFLOAD)) - continue; - - switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen, - fi, fa->fa_tos, fa->fa_type, - tb->tb_id); - } - - /* update leaf slen */ - n->slen = slen; - - if (hlist_empty(&n->leaf)) { - put_child_root(pn, n->key, NULL); - node_free(n); - } - } -} - /* Caller must hold RTNL. */ -int fib_table_flush(struct fib_table *tb) +int fib_table_flush(struct net *net, struct fib_table *tb) { struct trie *t = (struct trie *)tb->tb_data; struct key_vector *pn = t->kv; @@ -1858,9 +1810,11 @@ int fib_table_flush(struct fib_table *tb) continue; } - switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen, - fi, fa->fa_tos, fa->fa_type, - tb->tb_id); + call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, + n->key, + KEYLENGTH - fa->fa_slen, + fi, fa->fa_tos, fa->fa_type, + tb->tb_id, 0); hlist_del_rcu(&fa->fa_list); fib_release_info(fa->fa_info); alias_free_mem_rcu(fa); diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c index ecd1e09..96e0efe 100644 --- a/net/ipv4/gre_offload.c +++ b/net/ipv4/gre_offload.c @@ -24,7 +24,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, __be16 protocol = skb->protocol; u16 mac_len = skb->mac_len; int gre_offset, outer_hlen; - bool need_csum, ufo; + bool need_csum, ufo, gso_partial; if (!skb->encapsulation) goto out; @@ -69,6 +69,8 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, goto out; } + gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); + outer_hlen = skb_tnl_header_len(skb); gre_offset = outer_hlen - tnl_hlen; skb = segs; @@ -96,7 +98,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, greh = (struct gre_base_hdr *)skb_transport_header(skb); pcsum = (__sum16 *)(greh + 1); - if (skb_is_gso(skb)) { + if (gso_partial) { unsigned int partial_adj; /* Adjust checksum to account for the fact that diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index 4b351af..d6feabb 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -312,6 +312,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { const struct iphdr *iph = ip_hdr(skb); struct rtable *rt; + struct net_device *dev = skb->dev; /* if ingress device is enslaved to an L3 master device pass the * skb to its handler for processing @@ -341,7 +342,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) */ if (!skb_valid_dst(skb)) { int err = ip_route_input_noref(skb, iph->daddr, iph->saddr, - iph->tos, skb->dev); + iph->tos, dev); if (unlikely(err)) { if (err == -EXDEV) __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER); @@ -370,7 +371,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) __IP_UPD_PO_STATS(net, IPSTATS_MIB_INBCAST, skb->len); } else if (skb->pkt_type == PACKET_BROADCAST || skb->pkt_type == PACKET_MULTICAST) { - struct in_device *in_dev = __in_dev_get_rcu(skb->dev); + struct in_device *in_dev = __in_dev_get_rcu(dev); /* RFC 1122 3.3.6: * diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c index cc701fa..5d7944f 100644 --- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -88,6 +88,7 @@ static int vti_rcv_cb(struct sk_buff *skb, int err) struct net_device *dev; struct pcpu_sw_netstats *tstats; struct xfrm_state *x; + struct xfrm_mode *inner_mode; struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4; u32 orig_mark = skb->mark; int ret; @@ -105,7 +106,19 @@ static int vti_rcv_cb(struct sk_buff *skb, int err) } x = xfrm_input_state(skb); - family = x->inner_mode->afinfo->family; + + inner_mode = x->inner_mode; + + if (x->sel.family == AF_UNSPEC) { + inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); + if (inner_mode == NULL) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINSTATEMODEERROR); + return -EINVAL; + } + } + + family = inner_mode->afinfo->family; skb->mark = be32_to_cpu(tunnel->parms.i_key); ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 2625332..5f006e1 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2076,6 +2076,7 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, struct rta_mfc_stats mfcs; struct nlattr *mp_attr; struct rtnexthop *nhp; + unsigned long lastuse; int ct; /* If cache is unresolved, don't try to parse IIF and OIF */ @@ -2105,12 +2106,14 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, nla_nest_end(skb, mp_attr); + lastuse = READ_ONCE(c->mfc_un.res.lastuse); + lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0; + mfcs.mfcs_packets = c->mfc_un.res.pkt; mfcs.mfcs_bytes = c->mfc_un.res.bytes; mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if; if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) || - nla_put_u64_64bit(skb, RTA_EXPIRES, - jiffies_to_clock_t(c->mfc_un.res.lastuse), + nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse), RTA_PAD)) return -EMSGSIZE; @@ -2120,7 +2123,7 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, int ipmr_get_route(struct net *net, struct sk_buff *skb, __be32 saddr, __be32 daddr, - struct rtmsg *rtm, int nowait) + struct rtmsg *rtm, int nowait, u32 portid) { struct mfc_cache *cache; struct mr_table *mrt; @@ -2165,6 +2168,7 @@ int ipmr_get_route(struct net *net, struct sk_buff *skb, return -ENOMEM; } + NETLINK_CB(skb2).portid = portid; skb_push(skb2, sizeof(struct iphdr)); skb_reset_network_header(skb2); iph = ip_hdr(skb2); diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index f993545..7c00ce9 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -156,7 +156,7 @@ static struct nf_loginfo trace_loginfo = { .u = { .log = { .level = 4, - .logflags = NF_LOG_MASK, + .logflags = NF_LOG_DEFAULT_MASK, }, }, }; diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c index 870aebd..713c09a 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c @@ -110,7 +110,7 @@ static unsigned int ipv4_helper(void *priv, if (!help) return NF_ACCEPT; - /* rcu_read_lock()ed by nf_hook_slow */ + /* rcu_read_lock()ed by nf_hook_thresh */ helper = rcu_dereference(help->helper); if (!helper) return NF_ACCEPT; diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c index 4b5904b..d075b3c 100644 --- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c +++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c @@ -149,7 +149,7 @@ icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, return -NF_ACCEPT; } - /* rcu_read_lock()ed by nf_hook_slow */ + /* rcu_read_lock()ed by nf_hook_thresh */ innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum); /* Ordinarily, we'd expect the inverted tupleproto, but it's diff --git a/net/ipv4/netfilter/nf_log_arp.c b/net/ipv4/netfilter/nf_log_arp.c index 8945c26..b24795e 100644 --- a/net/ipv4/netfilter/nf_log_arp.c +++ b/net/ipv4/netfilter/nf_log_arp.c @@ -30,7 +30,7 @@ static struct nf_loginfo default_loginfo = { .u = { .log = { .level = LOGLEVEL_NOTICE, - .logflags = NF_LOG_MASK, + .logflags = NF_LOG_DEFAULT_MASK, }, }, }; diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c index 20f2255..8566489 100644 --- a/net/ipv4/netfilter/nf_log_ipv4.c +++ b/net/ipv4/netfilter/nf_log_ipv4.c @@ -29,7 +29,7 @@ static struct nf_loginfo default_loginfo = { .u = { .log = { .level = LOGLEVEL_NOTICE, - .logflags = NF_LOG_MASK, + .logflags = NF_LOG_DEFAULT_MASK, }, }, }; @@ -46,7 +46,7 @@ static void dump_ipv4_packet(struct nf_log_buf *m, if (info->type == NF_LOG_TYPE_LOG) logflags = info->u.log.logflags; else - logflags = NF_LOG_MASK; + logflags = NF_LOG_DEFAULT_MASK; ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); if (ih == NULL) { @@ -76,7 +76,7 @@ static void dump_ipv4_packet(struct nf_log_buf *m, if (ntohs(ih->frag_off) & IP_OFFSET) nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); - if ((logflags & XT_LOG_IPOPT) && + if ((logflags & NF_LOG_IPOPT) && ih->ihl * 4 > sizeof(struct iphdr)) { const unsigned char *op; unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; @@ -250,7 +250,7 @@ static void dump_ipv4_packet(struct nf_log_buf *m, } /* Max length: 15 "UID=4294967295 " */ - if ((logflags & XT_LOG_UID) && !iphoff) + if ((logflags & NF_LOG_UID) && !iphoff) nf_log_dump_sk_uid_gid(m, skb->sk); /* Max length: 16 "MARK=0xFFFFFFFF " */ @@ -282,7 +282,7 @@ static void dump_ipv4_mac_header(struct nf_log_buf *m, if (info->type == NF_LOG_TYPE_LOG) logflags = info->u.log.logflags; - if (!(logflags & XT_LOG_MACDECODE)) + if (!(logflags & NF_LOG_MACDECODE)) goto fallback; switch (dev->type) { diff --git a/net/ipv4/netfilter/nf_nat_proto_gre.c b/net/ipv4/netfilter/nf_nat_proto_gre.c index 9414923..edf0500 100644 --- a/net/ipv4/netfilter/nf_nat_proto_gre.c +++ b/net/ipv4/netfilter/nf_nat_proto_gre.c @@ -88,8 +88,8 @@ gre_manip_pkt(struct sk_buff *skb, const struct nf_conntrack_tuple *tuple, enum nf_nat_manip_type maniptype) { - const struct gre_hdr *greh; - struct gre_hdr_pptp *pgreh; + const struct gre_base_hdr *greh; + struct pptp_gre_header *pgreh; /* pgreh includes two optional 32bit fields which are not required * to be there. That's where the magic '8' comes from */ @@ -97,18 +97,19 @@ gre_manip_pkt(struct sk_buff *skb, return false; greh = (void *)skb->data + hdroff; - pgreh = (struct gre_hdr_pptp *)greh; + pgreh = (struct pptp_gre_header *)greh; /* we only have destination manip of a packet, since 'source key' * is not present in the packet itself */ if (maniptype != NF_NAT_MANIP_DST) return true; - switch (greh->version) { - case GRE_VERSION_1701: + + switch (greh->flags & GRE_VERSION) { + case GRE_VERSION_0: /* We do not currently NAT any GREv0 packets. * Try to behave like "nf_nat_proto_unknown" */ break; - case GRE_VERSION_PPTP: + case GRE_VERSION_1: pr_debug("call_id -> 0x%04x\n", ntohs(tuple->dst.u.gre.key)); pgreh->call_id = tuple->dst.u.gre.key; break; diff --git a/net/ipv4/netfilter/nf_tables_arp.c b/net/ipv4/netfilter/nf_tables_arp.c index cd84d42..805c8dd 100644 --- a/net/ipv4/netfilter/nf_tables_arp.c +++ b/net/ipv4/netfilter/nf_tables_arp.c @@ -21,7 +21,7 @@ nft_do_chain_arp(void *priv, { struct nft_pktinfo pkt; - nft_set_pktinfo(&pkt, skb, state); + nft_set_pktinfo_unspec(&pkt, skb, state); return nft_do_chain(&pkt, priv); } @@ -80,7 +80,10 @@ static int __init nf_tables_arp_init(void) { int ret; - nft_register_chain_type(&filter_arp); + ret = nft_register_chain_type(&filter_arp); + if (ret < 0) + return ret; + ret = register_pernet_subsys(&nf_tables_arp_net_ops); if (ret < 0) nft_unregister_chain_type(&filter_arp); diff --git a/net/ipv4/netfilter/nf_tables_ipv4.c b/net/ipv4/netfilter/nf_tables_ipv4.c index e44ba3b..2840a29 100644 --- a/net/ipv4/netfilter/nf_tables_ipv4.c +++ b/net/ipv4/netfilter/nf_tables_ipv4.c @@ -103,7 +103,10 @@ static int __init nf_tables_ipv4_init(void) { int ret; - nft_register_chain_type(&filter_ipv4); + ret = nft_register_chain_type(&filter_ipv4); + if (ret < 0) + return ret; + ret = register_pernet_subsys(&nf_tables_ipv4_net_ops); if (ret < 0) nft_unregister_chain_type(&filter_ipv4); diff --git a/net/ipv4/netfilter/nft_chain_route_ipv4.c b/net/ipv4/netfilter/nft_chain_route_ipv4.c index 2375b0a..30493be 100644 --- a/net/ipv4/netfilter/nft_chain_route_ipv4.c +++ b/net/ipv4/netfilter/nft_chain_route_ipv4.c @@ -31,6 +31,7 @@ static unsigned int nf_route_table_hook(void *priv, __be32 saddr, daddr; u_int8_t tos; const struct iphdr *iph; + int err; /* root is playing with raw sockets. */ if (skb->len < sizeof(struct iphdr) || @@ -46,15 +47,17 @@ static unsigned int nf_route_table_hook(void *priv, tos = iph->tos; ret = nft_do_chain(&pkt, priv); - if (ret != NF_DROP && ret != NF_QUEUE) { + if (ret != NF_DROP && ret != NF_STOLEN) { iph = ip_hdr(skb); if (iph->saddr != saddr || iph->daddr != daddr || skb->mark != mark || - iph->tos != tos) - if (ip_route_me_harder(state->net, skb, RTN_UNSPEC)) - ret = NF_DROP; + iph->tos != tos) { + err = ip_route_me_harder(state->net, skb, RTN_UNSPEC); + if (err < 0) + ret = NF_DROP_ERR(err); + } } return ret; } diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index 1ed015e..7143ca1 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -46,6 +46,8 @@ #include <net/sock.h> #include <net/raw.h> +#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX) + /* * Report socket allocation statistics [mea@utu.fi] */ @@ -356,22 +358,22 @@ static void icmp_put(struct seq_file *seq) atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs; seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors"); - for (i = 0; icmpmibmap[i].name != NULL; i++) + for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " In%s", icmpmibmap[i].name); seq_puts(seq, " OutMsgs OutErrors"); - for (i = 0; icmpmibmap[i].name != NULL; i++) + for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " Out%s", icmpmibmap[i].name); seq_printf(seq, "\nIcmp: %lu %lu %lu", snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS), snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS), snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS)); - for (i = 0; icmpmibmap[i].name != NULL; i++) + for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " %lu", atomic_long_read(ptr + icmpmibmap[i].index)); seq_printf(seq, " %lu %lu", snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS), snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS)); - for (i = 0; icmpmibmap[i].name != NULL; i++) + for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " %lu", atomic_long_read(ptr + (icmpmibmap[i].index | 0x100))); } @@ -379,14 +381,16 @@ static void icmp_put(struct seq_file *seq) /* * Called from the PROCfs module. This outputs /proc/net/snmp. */ -static int snmp_seq_show(struct seq_file *seq, void *v) +static int snmp_seq_show_ipstats(struct seq_file *seq, void *v) { - int i; struct net *net = seq->private; + u64 buff64[IPSTATS_MIB_MAX]; + int i; - seq_puts(seq, "Ip: Forwarding DefaultTTL"); + memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64)); - for (i = 0; snmp4_ipstats_list[i].name != NULL; i++) + seq_puts(seq, "Ip: Forwarding DefaultTTL"); + for (i = 0; snmp4_ipstats_list[i].name; i++) seq_printf(seq, " %s", snmp4_ipstats_list[i].name); seq_printf(seq, "\nIp: %d %d", @@ -394,57 +398,77 @@ static int snmp_seq_show(struct seq_file *seq, void *v) net->ipv4.sysctl_ip_default_ttl); BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0); - for (i = 0; snmp4_ipstats_list[i].name != NULL; i++) - seq_printf(seq, " %llu", - snmp_fold_field64(net->mib.ip_statistics, - snmp4_ipstats_list[i].entry, - offsetof(struct ipstats_mib, syncp))); + snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list, + net->mib.ip_statistics, + offsetof(struct ipstats_mib, syncp)); + for (i = 0; snmp4_ipstats_list[i].name; i++) + seq_printf(seq, " %llu", buff64[i]); - icmp_put(seq); /* RFC 2011 compatibility */ - icmpmsg_put(seq); + return 0; +} + +static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v) +{ + unsigned long buff[TCPUDP_MIB_MAX]; + struct net *net = seq->private; + int i; + + memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); seq_puts(seq, "\nTcp:"); - for (i = 0; snmp4_tcp_list[i].name != NULL; i++) + for (i = 0; snmp4_tcp_list[i].name; i++) seq_printf(seq, " %s", snmp4_tcp_list[i].name); seq_puts(seq, "\nTcp:"); - for (i = 0; snmp4_tcp_list[i].name != NULL; i++) { + snmp_get_cpu_field_batch(buff, snmp4_tcp_list, + net->mib.tcp_statistics); + for (i = 0; snmp4_tcp_list[i].name; i++) { /* MaxConn field is signed, RFC 2012 */ if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN) - seq_printf(seq, " %ld", - snmp_fold_field(net->mib.tcp_statistics, - snmp4_tcp_list[i].entry)); + seq_printf(seq, " %ld", buff[i]); else - seq_printf(seq, " %lu", - snmp_fold_field(net->mib.tcp_statistics, - snmp4_tcp_list[i].entry)); + seq_printf(seq, " %lu", buff[i]); } + memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + + snmp_get_cpu_field_batch(buff, snmp4_udp_list, + net->mib.udp_statistics); seq_puts(seq, "\nUdp:"); - for (i = 0; snmp4_udp_list[i].name != NULL; i++) + for (i = 0; snmp4_udp_list[i].name; i++) seq_printf(seq, " %s", snmp4_udp_list[i].name); - seq_puts(seq, "\nUdp:"); - for (i = 0; snmp4_udp_list[i].name != NULL; i++) - seq_printf(seq, " %lu", - snmp_fold_field(net->mib.udp_statistics, - snmp4_udp_list[i].entry)); + for (i = 0; snmp4_udp_list[i].name; i++) + seq_printf(seq, " %lu", buff[i]); + + memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); /* the UDP and UDP-Lite MIBs are the same */ seq_puts(seq, "\nUdpLite:"); - for (i = 0; snmp4_udp_list[i].name != NULL; i++) + snmp_get_cpu_field_batch(buff, snmp4_udp_list, + net->mib.udplite_statistics); + for (i = 0; snmp4_udp_list[i].name; i++) seq_printf(seq, " %s", snmp4_udp_list[i].name); - seq_puts(seq, "\nUdpLite:"); - for (i = 0; snmp4_udp_list[i].name != NULL; i++) - seq_printf(seq, " %lu", - snmp_fold_field(net->mib.udplite_statistics, - snmp4_udp_list[i].entry)); + for (i = 0; snmp4_udp_list[i].name; i++) + seq_printf(seq, " %lu", buff[i]); seq_putc(seq, '\n'); return 0; } +static int snmp_seq_show(struct seq_file *seq, void *v) +{ + snmp_seq_show_ipstats(seq, v); + + icmp_put(seq); /* RFC 2011 compatibility */ + icmpmsg_put(seq); + + snmp_seq_show_tcp_udp(seq, v); + + return 0; +} + static int snmp_seq_open(struct inode *inode, struct file *file) { return single_open_net(inode, file, snmp_seq_show); @@ -469,21 +493,21 @@ static int netstat_seq_show(struct seq_file *seq, void *v) struct net *net = seq->private; seq_puts(seq, "TcpExt:"); - for (i = 0; snmp4_net_list[i].name != NULL; i++) + for (i = 0; snmp4_net_list[i].name; i++) seq_printf(seq, " %s", snmp4_net_list[i].name); seq_puts(seq, "\nTcpExt:"); - for (i = 0; snmp4_net_list[i].name != NULL; i++) + for (i = 0; snmp4_net_list[i].name; i++) seq_printf(seq, " %lu", snmp_fold_field(net->mib.net_statistics, snmp4_net_list[i].entry)); seq_puts(seq, "\nIpExt:"); - for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++) + for (i = 0; snmp4_ipextstats_list[i].name; i++) seq_printf(seq, " %s", snmp4_ipextstats_list[i].name); seq_puts(seq, "\nIpExt:"); - for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++) + for (i = 0; snmp4_ipextstats_list[i].name; i++) seq_printf(seq, " %llu", snmp_fold_field64(net->mib.ip_statistics, snmp4_ipextstats_list[i].entry, diff --git a/net/ipv4/route.c b/net/ipv4/route.c index b52496f..f2be689 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -476,12 +476,18 @@ u32 ip_idents_reserve(u32 hash, int segs) atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; u32 old = ACCESS_ONCE(*p_tstamp); u32 now = (u32)jiffies; - u32 delta = 0; + u32 new, delta = 0; if (old != now && cmpxchg(p_tstamp, old, now) == old) delta = prandom_u32_max(now - old); - return atomic_add_return(segs + delta, p_id) - segs; + /* Do not use atomic_add_return() as it makes UBSAN unhappy */ + do { + old = (u32)atomic_read(p_id); + new = old + delta + segs; + } while (atomic_cmpxchg(p_id, old, new) != old); + + return new - segs; } EXPORT_SYMBOL(ip_idents_reserve); @@ -2494,7 +2500,8 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id, IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { int err = ipmr_get_route(net, skb, fl4->saddr, fl4->daddr, - r, nowait); + r, nowait, portid); + if (err <= 0) { if (!nowait) { if (err == 0) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 7dae800..f253e50 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -387,7 +387,7 @@ void tcp_init_sock(struct sock *sk) icsk->icsk_rto = TCP_TIMEOUT_INIT; tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); - tp->rtt_min[0].rtt = ~0U; + minmax_reset(&tp->rtt_min, tcp_time_stamp, ~0U); /* So many TCP implementations out there (incorrectly) count the * initial SYN frame in their delayed-ACK and congestion control @@ -396,6 +396,9 @@ void tcp_init_sock(struct sock *sk) */ tp->snd_cwnd = TCP_INIT_CWND; + /* There's a bubble in the pipe until at least the first ACK. */ + tp->app_limited = ~0U; + /* See draft-stevens-tcpca-spec-01 for discussion of the * initialization of these values. */ @@ -1014,6 +1017,9 @@ int tcp_sendpage(struct sock *sk, struct page *page, int offset, flags); lock_sock(sk); + + tcp_rate_check_app_limited(sk); /* is sending application-limited? */ + res = do_tcp_sendpages(sk, page, offset, size, flags); release_sock(sk); return res; @@ -1115,6 +1121,8 @@ int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); + tcp_rate_check_app_limited(sk); /* is sending application-limited? */ + /* Wait for a connection to finish. One exception is TCP Fast Open * (passive side) where data is allowed to be sent before a connection * is fully established. @@ -2704,7 +2712,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) { const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ const struct inet_connection_sock *icsk = inet_csk(sk); - u32 now = tcp_time_stamp; + u32 now = tcp_time_stamp, intv; unsigned int start; int notsent_bytes; u64 rate64; @@ -2794,6 +2802,15 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) info->tcpi_min_rtt = tcp_min_rtt(tp); info->tcpi_data_segs_in = tp->data_segs_in; info->tcpi_data_segs_out = tp->data_segs_out; + + info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0; + rate = READ_ONCE(tp->rate_delivered); + intv = READ_ONCE(tp->rate_interval_us); + if (rate && intv) { + rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC; + do_div(rate64, intv); + put_unaligned(rate64, &info->tcpi_delivery_rate); + } } EXPORT_SYMBOL_GPL(tcp_get_info); @@ -3261,11 +3278,12 @@ static void __init tcp_init_mem(void) void __init tcp_init(void) { - unsigned long limit; int max_rshare, max_wshare, cnt; + unsigned long limit; unsigned int i; - sock_skb_cb_check_size(sizeof(struct tcp_skb_cb)); + BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > + FIELD_SIZEOF(struct sk_buff, cb)); percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c new file mode 100644 index 0000000..0ea66c2 --- /dev/null +++ b/net/ipv4/tcp_bbr.c @@ -0,0 +1,896 @@ +/* Bottleneck Bandwidth and RTT (BBR) congestion control + * + * BBR congestion control computes the sending rate based on the delivery + * rate (throughput) estimated from ACKs. In a nutshell: + * + * On each ACK, update our model of the network path: + * bottleneck_bandwidth = windowed_max(delivered / elapsed, 10 round trips) + * min_rtt = windowed_min(rtt, 10 seconds) + * pacing_rate = pacing_gain * bottleneck_bandwidth + * cwnd = max(cwnd_gain * bottleneck_bandwidth * min_rtt, 4) + * + * The core algorithm does not react directly to packet losses or delays, + * although BBR may adjust the size of next send per ACK when loss is + * observed, or adjust the sending rate if it estimates there is a + * traffic policer, in order to keep the drop rate reasonable. + * + * BBR is described in detail in: + * "BBR: Congestion-Based Congestion Control", + * Neal Cardwell, Yuchung Cheng, C. Stephen Gunn, Soheil Hassas Yeganeh, + * Van Jacobson. ACM Queue, Vol. 14 No. 5, September-October 2016. + * + * There is a public e-mail list for discussing BBR development and testing: + * https://groups.google.com/forum/#!forum/bbr-dev + * + * NOTE: BBR *must* be used with the fq qdisc ("man tc-fq") with pacing enabled, + * since pacing is integral to the BBR design and implementation. + * BBR without pacing would not function properly, and may incur unnecessary + * high packet loss rates. + */ +#include <linux/module.h> +#include <net/tcp.h> +#include <linux/inet_diag.h> +#include <linux/inet.h> +#include <linux/random.h> +#include <linux/win_minmax.h> + +/* Scale factor for rate in pkt/uSec unit to avoid truncation in bandwidth + * estimation. The rate unit ~= (1500 bytes / 1 usec / 2^24) ~= 715 bps. + * This handles bandwidths from 0.06pps (715bps) to 256Mpps (3Tbps) in a u32. + * Since the minimum window is >=4 packets, the lower bound isn't + * an issue. The upper bound isn't an issue with existing technologies. + */ +#define BW_SCALE 24 +#define BW_UNIT (1 << BW_SCALE) + +#define BBR_SCALE 8 /* scaling factor for fractions in BBR (e.g. gains) */ +#define BBR_UNIT (1 << BBR_SCALE) + +/* BBR has the following modes for deciding how fast to send: */ +enum bbr_mode { + BBR_STARTUP, /* ramp up sending rate rapidly to fill pipe */ + BBR_DRAIN, /* drain any queue created during startup */ + BBR_PROBE_BW, /* discover, share bw: pace around estimated bw */ + BBR_PROBE_RTT, /* cut cwnd to min to probe min_rtt */ +}; + +/* BBR congestion control block */ +struct bbr { + u32 min_rtt_us; /* min RTT in min_rtt_win_sec window */ + u32 min_rtt_stamp; /* timestamp of min_rtt_us */ + u32 probe_rtt_done_stamp; /* end time for BBR_PROBE_RTT mode */ + struct minmax bw; /* Max recent delivery rate in pkts/uS << 24 */ + u32 rtt_cnt; /* count of packet-timed rounds elapsed */ + u32 next_rtt_delivered; /* scb->tx.delivered at end of round */ + struct skb_mstamp cycle_mstamp; /* time of this cycle phase start */ + u32 mode:3, /* current bbr_mode in state machine */ + prev_ca_state:3, /* CA state on previous ACK */ + packet_conservation:1, /* use packet conservation? */ + restore_cwnd:1, /* decided to revert cwnd to old value */ + round_start:1, /* start of packet-timed tx->ack round? */ + tso_segs_goal:7, /* segments we want in each skb we send */ + idle_restart:1, /* restarting after idle? */ + probe_rtt_round_done:1, /* a BBR_PROBE_RTT round at 4 pkts? */ + unused:5, + lt_is_sampling:1, /* taking long-term ("LT") samples now? */ + lt_rtt_cnt:7, /* round trips in long-term interval */ + lt_use_bw:1; /* use lt_bw as our bw estimate? */ + u32 lt_bw; /* LT est delivery rate in pkts/uS << 24 */ + u32 lt_last_delivered; /* LT intvl start: tp->delivered */ + u32 lt_last_stamp; /* LT intvl start: tp->delivered_mstamp */ + u32 lt_last_lost; /* LT intvl start: tp->lost */ + u32 pacing_gain:10, /* current gain for setting pacing rate */ + cwnd_gain:10, /* current gain for setting cwnd */ + full_bw_cnt:3, /* number of rounds without large bw gains */ + cycle_idx:3, /* current index in pacing_gain cycle array */ + unused_b:6; + u32 prior_cwnd; /* prior cwnd upon entering loss recovery */ + u32 full_bw; /* recent bw, to estimate if pipe is full */ +}; + +#define CYCLE_LEN 8 /* number of phases in a pacing gain cycle */ + +/* Window length of bw filter (in rounds): */ +static const int bbr_bw_rtts = CYCLE_LEN + 2; +/* Window length of min_rtt filter (in sec): */ +static const u32 bbr_min_rtt_win_sec = 10; +/* Minimum time (in ms) spent at bbr_cwnd_min_target in BBR_PROBE_RTT mode: */ +static const u32 bbr_probe_rtt_mode_ms = 200; +/* Skip TSO below the following bandwidth (bits/sec): */ +static const int bbr_min_tso_rate = 1200000; + +/* We use a high_gain value of 2/ln(2) because it's the smallest pacing gain + * that will allow a smoothly increasing pacing rate that will double each RTT + * and send the same number of packets per RTT that an un-paced, slow-starting + * Reno or CUBIC flow would: + */ +static const int bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1; +/* The pacing gain of 1/high_gain in BBR_DRAIN is calculated to typically drain + * the queue created in BBR_STARTUP in a single round: + */ +static const int bbr_drain_gain = BBR_UNIT * 1000 / 2885; +/* The gain for deriving steady-state cwnd tolerates delayed/stretched ACKs: */ +static const int bbr_cwnd_gain = BBR_UNIT * 2; +/* The pacing_gain values for the PROBE_BW gain cycle, to discover/share bw: */ +static const int bbr_pacing_gain[] = { + BBR_UNIT * 5 / 4, /* probe for more available bw */ + BBR_UNIT * 3 / 4, /* drain queue and/or yield bw to other flows */ + BBR_UNIT, BBR_UNIT, BBR_UNIT, /* cruise at 1.0*bw to utilize pipe, */ + BBR_UNIT, BBR_UNIT, BBR_UNIT /* without creating excess queue... */ +}; +/* Randomize the starting gain cycling phase over N phases: */ +static const u32 bbr_cycle_rand = 7; + +/* Try to keep at least this many packets in flight, if things go smoothly. For + * smooth functioning, a sliding window protocol ACKing every other packet + * needs at least 4 packets in flight: + */ +static const u32 bbr_cwnd_min_target = 4; + +/* To estimate if BBR_STARTUP mode (i.e. high_gain) has filled pipe... */ +/* If bw has increased significantly (1.25x), there may be more bw available: */ +static const u32 bbr_full_bw_thresh = BBR_UNIT * 5 / 4; +/* But after 3 rounds w/o significant bw growth, estimate pipe is full: */ +static const u32 bbr_full_bw_cnt = 3; + +/* "long-term" ("LT") bandwidth estimator parameters... */ +/* The minimum number of rounds in an LT bw sampling interval: */ +static const u32 bbr_lt_intvl_min_rtts = 4; +/* If lost/delivered ratio > 20%, interval is "lossy" and we may be policed: */ +static const u32 bbr_lt_loss_thresh = 50; +/* If 2 intervals have a bw ratio <= 1/8, their bw is "consistent": */ +static const u32 bbr_lt_bw_ratio = BBR_UNIT / 8; +/* If 2 intervals have a bw diff <= 4 Kbit/sec their bw is "consistent": */ +static const u32 bbr_lt_bw_diff = 4000 / 8; +/* If we estimate we're policed, use lt_bw for this many round trips: */ +static const u32 bbr_lt_bw_max_rtts = 48; + +/* Do we estimate that STARTUP filled the pipe? */ +static bool bbr_full_bw_reached(const struct sock *sk) +{ + const struct bbr *bbr = inet_csk_ca(sk); + + return bbr->full_bw_cnt >= bbr_full_bw_cnt; +} + +/* Return the windowed max recent bandwidth sample, in pkts/uS << BW_SCALE. */ +static u32 bbr_max_bw(const struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + return minmax_get(&bbr->bw); +} + +/* Return the estimated bandwidth of the path, in pkts/uS << BW_SCALE. */ +static u32 bbr_bw(const struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + return bbr->lt_use_bw ? bbr->lt_bw : bbr_max_bw(sk); +} + +/* Return rate in bytes per second, optionally with a gain. + * The order here is chosen carefully to avoid overflow of u64. This should + * work for input rates of up to 2.9Tbit/sec and gain of 2.89x. + */ +static u64 bbr_rate_bytes_per_sec(struct sock *sk, u64 rate, int gain) +{ + rate *= tcp_mss_to_mtu(sk, tcp_sk(sk)->mss_cache); + rate *= gain; + rate >>= BBR_SCALE; + rate *= USEC_PER_SEC; + return rate >> BW_SCALE; +} + +/* Pace using current bw estimate and a gain factor. In order to help drive the + * network toward lower queues while maintaining high utilization and low + * latency, the average pacing rate aims to be slightly (~1%) lower than the + * estimated bandwidth. This is an important aspect of the design. In this + * implementation this slightly lower pacing rate is achieved implicitly by not + * including link-layer headers in the packet size used for the pacing rate. + */ +static void bbr_set_pacing_rate(struct sock *sk, u32 bw, int gain) +{ + struct bbr *bbr = inet_csk_ca(sk); + u64 rate = bw; + + rate = bbr_rate_bytes_per_sec(sk, rate, gain); + rate = min_t(u64, rate, sk->sk_max_pacing_rate); + if (bbr->mode != BBR_STARTUP || rate > sk->sk_pacing_rate) + sk->sk_pacing_rate = rate; +} + +/* Return count of segments we want in the skbs we send, or 0 for default. */ +static u32 bbr_tso_segs_goal(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + return bbr->tso_segs_goal; +} + +static void bbr_set_tso_segs_goal(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u32 min_segs; + + min_segs = sk->sk_pacing_rate < (bbr_min_tso_rate >> 3) ? 1 : 2; + bbr->tso_segs_goal = min(tcp_tso_autosize(sk, tp->mss_cache, min_segs), + 0x7FU); +} + +/* Save "last known good" cwnd so we can restore it after losses or PROBE_RTT */ +static void bbr_save_cwnd(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + if (bbr->prev_ca_state < TCP_CA_Recovery && bbr->mode != BBR_PROBE_RTT) + bbr->prior_cwnd = tp->snd_cwnd; /* this cwnd is good enough */ + else /* loss recovery or BBR_PROBE_RTT have temporarily cut cwnd */ + bbr->prior_cwnd = max(bbr->prior_cwnd, tp->snd_cwnd); +} + +static void bbr_cwnd_event(struct sock *sk, enum tcp_ca_event event) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + if (event == CA_EVENT_TX_START && tp->app_limited) { + bbr->idle_restart = 1; + /* Avoid pointless buffer overflows: pace at est. bw if we don't + * need more speed (we're restarting from idle and app-limited). + */ + if (bbr->mode == BBR_PROBE_BW) + bbr_set_pacing_rate(sk, bbr_bw(sk), BBR_UNIT); + } +} + +/* Find target cwnd. Right-size the cwnd based on min RTT and the + * estimated bottleneck bandwidth: + * + * cwnd = bw * min_rtt * gain = BDP * gain + * + * The key factor, gain, controls the amount of queue. While a small gain + * builds a smaller queue, it becomes more vulnerable to noise in RTT + * measurements (e.g., delayed ACKs or other ACK compression effects). This + * noise may cause BBR to under-estimate the rate. + * + * To achieve full performance in high-speed paths, we budget enough cwnd to + * fit full-sized skbs in-flight on both end hosts to fully utilize the path: + * - one skb in sending host Qdisc, + * - one skb in sending host TSO/GSO engine + * - one skb being received by receiver host LRO/GRO/delayed-ACK engine + * Don't worry, at low rates (bbr_min_tso_rate) this won't bloat cwnd because + * in such cases tso_segs_goal is 1. The minimum cwnd is 4 packets, + * which allows 2 outstanding 2-packet sequences, to try to keep pipe + * full even with ACK-every-other-packet delayed ACKs. + */ +static u32 bbr_target_cwnd(struct sock *sk, u32 bw, int gain) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 cwnd; + u64 w; + + /* If we've never had a valid RTT sample, cap cwnd at the initial + * default. This should only happen when the connection is not using TCP + * timestamps and has retransmitted all of the SYN/SYNACK/data packets + * ACKed so far. In this case, an RTO can cut cwnd to 1, in which + * case we need to slow-start up toward something safe: TCP_INIT_CWND. + */ + if (unlikely(bbr->min_rtt_us == ~0U)) /* no valid RTT samples yet? */ + return TCP_INIT_CWND; /* be safe: cap at default initial cwnd*/ + + w = (u64)bw * bbr->min_rtt_us; + + /* Apply a gain to the given value, then remove the BW_SCALE shift. */ + cwnd = (((w * gain) >> BBR_SCALE) + BW_UNIT - 1) / BW_UNIT; + + /* Allow enough full-sized skbs in flight to utilize end systems. */ + cwnd += 3 * bbr->tso_segs_goal; + + /* Reduce delayed ACKs by rounding up cwnd to the next even number. */ + cwnd = (cwnd + 1) & ~1U; + + return cwnd; +} + +/* An optimization in BBR to reduce losses: On the first round of recovery, we + * follow the packet conservation principle: send P packets per P packets acked. + * After that, we slow-start and send at most 2*P packets per P packets acked. + * After recovery finishes, or upon undo, we restore the cwnd we had when + * recovery started (capped by the target cwnd based on estimated BDP). + * + * TODO(ycheng/ncardwell): implement a rate-based approach. + */ +static bool bbr_set_cwnd_to_recover_or_restore( + struct sock *sk, const struct rate_sample *rs, u32 acked, u32 *new_cwnd) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u8 prev_state = bbr->prev_ca_state, state = inet_csk(sk)->icsk_ca_state; + u32 cwnd = tp->snd_cwnd; + + /* An ACK for P pkts should release at most 2*P packets. We do this + * in two steps. First, here we deduct the number of lost packets. + * Then, in bbr_set_cwnd() we slow start up toward the target cwnd. + */ + if (rs->losses > 0) + cwnd = max_t(s32, cwnd - rs->losses, 1); + + if (state == TCP_CA_Recovery && prev_state != TCP_CA_Recovery) { + /* Starting 1st round of Recovery, so do packet conservation. */ + bbr->packet_conservation = 1; + bbr->next_rtt_delivered = tp->delivered; /* start round now */ + /* Cut unused cwnd from app behavior, TSQ, or TSO deferral: */ + cwnd = tcp_packets_in_flight(tp) + acked; + } else if (prev_state >= TCP_CA_Recovery && state < TCP_CA_Recovery) { + /* Exiting loss recovery; restore cwnd saved before recovery. */ + bbr->restore_cwnd = 1; + bbr->packet_conservation = 0; + } + bbr->prev_ca_state = state; + + if (bbr->restore_cwnd) { + /* Restore cwnd after exiting loss recovery or PROBE_RTT. */ + cwnd = max(cwnd, bbr->prior_cwnd); + bbr->restore_cwnd = 0; + } + + if (bbr->packet_conservation) { + *new_cwnd = max(cwnd, tcp_packets_in_flight(tp) + acked); + return true; /* yes, using packet conservation */ + } + *new_cwnd = cwnd; + return false; +} + +/* Slow-start up toward target cwnd (if bw estimate is growing, or packet loss + * has drawn us down below target), or snap down to target if we're above it. + */ +static void bbr_set_cwnd(struct sock *sk, const struct rate_sample *rs, + u32 acked, u32 bw, int gain) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u32 cwnd = 0, target_cwnd = 0; + + if (!acked) + return; + + if (bbr_set_cwnd_to_recover_or_restore(sk, rs, acked, &cwnd)) + goto done; + + /* If we're below target cwnd, slow start cwnd toward target cwnd. */ + target_cwnd = bbr_target_cwnd(sk, bw, gain); + if (bbr_full_bw_reached(sk)) /* only cut cwnd if we filled the pipe */ + cwnd = min(cwnd + acked, target_cwnd); + else if (cwnd < target_cwnd || tp->delivered < TCP_INIT_CWND) + cwnd = cwnd + acked; + cwnd = max(cwnd, bbr_cwnd_min_target); + +done: + tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp); /* apply global cap */ + if (bbr->mode == BBR_PROBE_RTT) /* drain queue, refresh min_rtt */ + tp->snd_cwnd = min(tp->snd_cwnd, bbr_cwnd_min_target); +} + +/* End cycle phase if it's time and/or we hit the phase's in-flight target. */ +static bool bbr_is_next_cycle_phase(struct sock *sk, + const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + bool is_full_length = + skb_mstamp_us_delta(&tp->delivered_mstamp, &bbr->cycle_mstamp) > + bbr->min_rtt_us; + u32 inflight, bw; + + /* The pacing_gain of 1.0 paces at the estimated bw to try to fully + * use the pipe without increasing the queue. + */ + if (bbr->pacing_gain == BBR_UNIT) + return is_full_length; /* just use wall clock time */ + + inflight = rs->prior_in_flight; /* what was in-flight before ACK? */ + bw = bbr_max_bw(sk); + + /* A pacing_gain > 1.0 probes for bw by trying to raise inflight to at + * least pacing_gain*BDP; this may take more than min_rtt if min_rtt is + * small (e.g. on a LAN). We do not persist if packets are lost, since + * a path with small buffers may not hold that much. + */ + if (bbr->pacing_gain > BBR_UNIT) + return is_full_length && + (rs->losses || /* perhaps pacing_gain*BDP won't fit */ + inflight >= bbr_target_cwnd(sk, bw, bbr->pacing_gain)); + + /* A pacing_gain < 1.0 tries to drain extra queue we added if bw + * probing didn't find more bw. If inflight falls to match BDP then we + * estimate queue is drained; persisting would underutilize the pipe. + */ + return is_full_length || + inflight <= bbr_target_cwnd(sk, bw, BBR_UNIT); +} + +static void bbr_advance_cycle_phase(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + bbr->cycle_idx = (bbr->cycle_idx + 1) & (CYCLE_LEN - 1); + bbr->cycle_mstamp = tp->delivered_mstamp; + bbr->pacing_gain = bbr_pacing_gain[bbr->cycle_idx]; +} + +/* Gain cycling: cycle pacing gain to converge to fair share of available bw. */ +static void bbr_update_cycle_phase(struct sock *sk, + const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + + if ((bbr->mode == BBR_PROBE_BW) && !bbr->lt_use_bw && + bbr_is_next_cycle_phase(sk, rs)) + bbr_advance_cycle_phase(sk); +} + +static void bbr_reset_startup_mode(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->mode = BBR_STARTUP; + bbr->pacing_gain = bbr_high_gain; + bbr->cwnd_gain = bbr_high_gain; +} + +static void bbr_reset_probe_bw_mode(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->mode = BBR_PROBE_BW; + bbr->pacing_gain = BBR_UNIT; + bbr->cwnd_gain = bbr_cwnd_gain; + bbr->cycle_idx = CYCLE_LEN - 1 - prandom_u32_max(bbr_cycle_rand); + bbr_advance_cycle_phase(sk); /* flip to next phase of gain cycle */ +} + +static void bbr_reset_mode(struct sock *sk) +{ + if (!bbr_full_bw_reached(sk)) + bbr_reset_startup_mode(sk); + else + bbr_reset_probe_bw_mode(sk); +} + +/* Start a new long-term sampling interval. */ +static void bbr_reset_lt_bw_sampling_interval(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + bbr->lt_last_stamp = tp->delivered_mstamp.stamp_jiffies; + bbr->lt_last_delivered = tp->delivered; + bbr->lt_last_lost = tp->lost; + bbr->lt_rtt_cnt = 0; +} + +/* Completely reset long-term bandwidth sampling. */ +static void bbr_reset_lt_bw_sampling(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->lt_bw = 0; + bbr->lt_use_bw = 0; + bbr->lt_is_sampling = false; + bbr_reset_lt_bw_sampling_interval(sk); +} + +/* Long-term bw sampling interval is done. Estimate whether we're policed. */ +static void bbr_lt_bw_interval_done(struct sock *sk, u32 bw) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 diff; + + if (bbr->lt_bw) { /* do we have bw from a previous interval? */ + /* Is new bw close to the lt_bw from the previous interval? */ + diff = abs(bw - bbr->lt_bw); + if ((diff * BBR_UNIT <= bbr_lt_bw_ratio * bbr->lt_bw) || + (bbr_rate_bytes_per_sec(sk, diff, BBR_UNIT) <= + bbr_lt_bw_diff)) { + /* All criteria are met; estimate we're policed. */ + bbr->lt_bw = (bw + bbr->lt_bw) >> 1; /* avg 2 intvls */ + bbr->lt_use_bw = 1; + bbr->pacing_gain = BBR_UNIT; /* try to avoid drops */ + bbr->lt_rtt_cnt = 0; + return; + } + } + bbr->lt_bw = bw; + bbr_reset_lt_bw_sampling_interval(sk); +} + +/* Token-bucket traffic policers are common (see "An Internet-Wide Analysis of + * Traffic Policing", SIGCOMM 2016). BBR detects token-bucket policers and + * explicitly models their policed rate, to reduce unnecessary losses. We + * estimate that we're policed if we see 2 consecutive sampling intervals with + * consistent throughput and high packet loss. If we think we're being policed, + * set lt_bw to the "long-term" average delivery rate from those 2 intervals. + */ +static void bbr_lt_bw_sampling(struct sock *sk, const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u32 lost, delivered; + u64 bw; + s32 t; + + if (bbr->lt_use_bw) { /* already using long-term rate, lt_bw? */ + if (bbr->mode == BBR_PROBE_BW && bbr->round_start && + ++bbr->lt_rtt_cnt >= bbr_lt_bw_max_rtts) { + bbr_reset_lt_bw_sampling(sk); /* stop using lt_bw */ + bbr_reset_probe_bw_mode(sk); /* restart gain cycling */ + } + return; + } + + /* Wait for the first loss before sampling, to let the policer exhaust + * its tokens and estimate the steady-state rate allowed by the policer. + * Starting samples earlier includes bursts that over-estimate the bw. + */ + if (!bbr->lt_is_sampling) { + if (!rs->losses) + return; + bbr_reset_lt_bw_sampling_interval(sk); + bbr->lt_is_sampling = true; + } + + /* To avoid underestimates, reset sampling if we run out of data. */ + if (rs->is_app_limited) { + bbr_reset_lt_bw_sampling(sk); + return; + } + + if (bbr->round_start) + bbr->lt_rtt_cnt++; /* count round trips in this interval */ + if (bbr->lt_rtt_cnt < bbr_lt_intvl_min_rtts) + return; /* sampling interval needs to be longer */ + if (bbr->lt_rtt_cnt > 4 * bbr_lt_intvl_min_rtts) { + bbr_reset_lt_bw_sampling(sk); /* interval is too long */ + return; + } + + /* End sampling interval when a packet is lost, so we estimate the + * policer tokens were exhausted. Stopping the sampling before the + * tokens are exhausted under-estimates the policed rate. + */ + if (!rs->losses) + return; + + /* Calculate packets lost and delivered in sampling interval. */ + lost = tp->lost - bbr->lt_last_lost; + delivered = tp->delivered - bbr->lt_last_delivered; + /* Is loss rate (lost/delivered) >= lt_loss_thresh? If not, wait. */ + if (!delivered || (lost << BBR_SCALE) < bbr_lt_loss_thresh * delivered) + return; + + /* Find average delivery rate in this sampling interval. */ + t = (s32)(tp->delivered_mstamp.stamp_jiffies - bbr->lt_last_stamp); + if (t < 1) + return; /* interval is less than one jiffy, so wait */ + t = jiffies_to_usecs(t); + /* Interval long enough for jiffies_to_usecs() to return a bogus 0? */ + if (t < 1) { + bbr_reset_lt_bw_sampling(sk); /* interval too long; reset */ + return; + } + bw = (u64)delivered * BW_UNIT; + do_div(bw, t); + bbr_lt_bw_interval_done(sk, bw); +} + +/* Estimate the bandwidth based on how fast packets are delivered */ +static void bbr_update_bw(struct sock *sk, const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 bw; + + bbr->round_start = 0; + if (rs->delivered < 0 || rs->interval_us <= 0) + return; /* Not a valid observation */ + + /* See if we've reached the next RTT */ + if (!before(rs->prior_delivered, bbr->next_rtt_delivered)) { + bbr->next_rtt_delivered = tp->delivered; + bbr->rtt_cnt++; + bbr->round_start = 1; + bbr->packet_conservation = 0; + } + + bbr_lt_bw_sampling(sk, rs); + + /* Divide delivered by the interval to find a (lower bound) bottleneck + * bandwidth sample. Delivered is in packets and interval_us in uS and + * ratio will be <<1 for most connections. So delivered is first scaled. + */ + bw = (u64)rs->delivered * BW_UNIT; + do_div(bw, rs->interval_us); + + /* If this sample is application-limited, it is likely to have a very + * low delivered count that represents application behavior rather than + * the available network rate. Such a sample could drag down estimated + * bw, causing needless slow-down. Thus, to continue to send at the + * last measured network rate, we filter out app-limited samples unless + * they describe the path bw at least as well as our bw model. + * + * So the goal during app-limited phase is to proceed with the best + * network rate no matter how long. We automatically leave this + * phase when app writes faster than the network can deliver :) + */ + if (!rs->is_app_limited || bw >= bbr_max_bw(sk)) { + /* Incorporate new sample into our max bw filter. */ + minmax_running_max(&bbr->bw, bbr_bw_rtts, bbr->rtt_cnt, bw); + } +} + +/* Estimate when the pipe is full, using the change in delivery rate: BBR + * estimates that STARTUP filled the pipe if the estimated bw hasn't changed by + * at least bbr_full_bw_thresh (25%) after bbr_full_bw_cnt (3) non-app-limited + * rounds. Why 3 rounds: 1: rwin autotuning grows the rwin, 2: we fill the + * higher rwin, 3: we get higher delivery rate samples. Or transient + * cross-traffic or radio noise can go away. CUBIC Hystart shares a similar + * design goal, but uses delay and inter-ACK spacing instead of bandwidth. + */ +static void bbr_check_full_bw_reached(struct sock *sk, + const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 bw_thresh; + + if (bbr_full_bw_reached(sk) || !bbr->round_start || rs->is_app_limited) + return; + + bw_thresh = (u64)bbr->full_bw * bbr_full_bw_thresh >> BBR_SCALE; + if (bbr_max_bw(sk) >= bw_thresh) { + bbr->full_bw = bbr_max_bw(sk); + bbr->full_bw_cnt = 0; + return; + } + ++bbr->full_bw_cnt; +} + +/* If pipe is probably full, drain the queue and then enter steady-state. */ +static void bbr_check_drain(struct sock *sk, const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + + if (bbr->mode == BBR_STARTUP && bbr_full_bw_reached(sk)) { + bbr->mode = BBR_DRAIN; /* drain queue we created */ + bbr->pacing_gain = bbr_drain_gain; /* pace slow to drain */ + bbr->cwnd_gain = bbr_high_gain; /* maintain cwnd */ + } /* fall through to check if in-flight is already small: */ + if (bbr->mode == BBR_DRAIN && + tcp_packets_in_flight(tcp_sk(sk)) <= + bbr_target_cwnd(sk, bbr_max_bw(sk), BBR_UNIT)) + bbr_reset_probe_bw_mode(sk); /* we estimate queue is drained */ +} + +/* The goal of PROBE_RTT mode is to have BBR flows cooperatively and + * periodically drain the bottleneck queue, to converge to measure the true + * min_rtt (unloaded propagation delay). This allows the flows to keep queues + * small (reducing queuing delay and packet loss) and achieve fairness among + * BBR flows. + * + * The min_rtt filter window is 10 seconds. When the min_rtt estimate expires, + * we enter PROBE_RTT mode and cap the cwnd at bbr_cwnd_min_target=4 packets. + * After at least bbr_probe_rtt_mode_ms=200ms and at least one packet-timed + * round trip elapsed with that flight size <= 4, we leave PROBE_RTT mode and + * re-enter the previous mode. BBR uses 200ms to approximately bound the + * performance penalty of PROBE_RTT's cwnd capping to roughly 2% (200ms/10s). + * + * Note that flows need only pay 2% if they are busy sending over the last 10 + * seconds. Interactive applications (e.g., Web, RPCs, video chunks) often have + * natural silences or low-rate periods within 10 seconds where the rate is low + * enough for long enough to drain its queue in the bottleneck. We pick up + * these min RTT measurements opportunistically with our min_rtt filter. :-) + */ +static void bbr_update_min_rtt(struct sock *sk, const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + bool filter_expired; + + /* Track min RTT seen in the min_rtt_win_sec filter window: */ + filter_expired = after(tcp_time_stamp, + bbr->min_rtt_stamp + bbr_min_rtt_win_sec * HZ); + if (rs->rtt_us >= 0 && + (rs->rtt_us <= bbr->min_rtt_us || filter_expired)) { + bbr->min_rtt_us = rs->rtt_us; + bbr->min_rtt_stamp = tcp_time_stamp; + } + + if (bbr_probe_rtt_mode_ms > 0 && filter_expired && + !bbr->idle_restart && bbr->mode != BBR_PROBE_RTT) { + bbr->mode = BBR_PROBE_RTT; /* dip, drain queue */ + bbr->pacing_gain = BBR_UNIT; + bbr->cwnd_gain = BBR_UNIT; + bbr_save_cwnd(sk); /* note cwnd so we can restore it */ + bbr->probe_rtt_done_stamp = 0; + } + + if (bbr->mode == BBR_PROBE_RTT) { + /* Ignore low rate samples during this mode. */ + tp->app_limited = + (tp->delivered + tcp_packets_in_flight(tp)) ? : 1; + /* Maintain min packets in flight for max(200 ms, 1 round). */ + if (!bbr->probe_rtt_done_stamp && + tcp_packets_in_flight(tp) <= bbr_cwnd_min_target) { + bbr->probe_rtt_done_stamp = tcp_time_stamp + + msecs_to_jiffies(bbr_probe_rtt_mode_ms); + bbr->probe_rtt_round_done = 0; + bbr->next_rtt_delivered = tp->delivered; + } else if (bbr->probe_rtt_done_stamp) { + if (bbr->round_start) + bbr->probe_rtt_round_done = 1; + if (bbr->probe_rtt_round_done && + after(tcp_time_stamp, bbr->probe_rtt_done_stamp)) { + bbr->min_rtt_stamp = tcp_time_stamp; + bbr->restore_cwnd = 1; /* snap to prior_cwnd */ + bbr_reset_mode(sk); + } + } + } + bbr->idle_restart = 0; +} + +static void bbr_update_model(struct sock *sk, const struct rate_sample *rs) +{ + bbr_update_bw(sk, rs); + bbr_update_cycle_phase(sk, rs); + bbr_check_full_bw_reached(sk, rs); + bbr_check_drain(sk, rs); + bbr_update_min_rtt(sk, rs); +} + +static void bbr_main(struct sock *sk, const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 bw; + + bbr_update_model(sk, rs); + + bw = bbr_bw(sk); + bbr_set_pacing_rate(sk, bw, bbr->pacing_gain); + bbr_set_tso_segs_goal(sk); + bbr_set_cwnd(sk, rs, rs->acked_sacked, bw, bbr->cwnd_gain); +} + +static void bbr_init(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 bw; + + bbr->prior_cwnd = 0; + bbr->tso_segs_goal = 0; /* default segs per skb until first ACK */ + bbr->rtt_cnt = 0; + bbr->next_rtt_delivered = 0; + bbr->prev_ca_state = TCP_CA_Open; + bbr->packet_conservation = 0; + + bbr->probe_rtt_done_stamp = 0; + bbr->probe_rtt_round_done = 0; + bbr->min_rtt_us = tcp_min_rtt(tp); + bbr->min_rtt_stamp = tcp_time_stamp; + + minmax_reset(&bbr->bw, bbr->rtt_cnt, 0); /* init max bw to 0 */ + + /* Initialize pacing rate to: high_gain * init_cwnd / RTT. */ + bw = (u64)tp->snd_cwnd * BW_UNIT; + do_div(bw, (tp->srtt_us >> 3) ? : USEC_PER_MSEC); + sk->sk_pacing_rate = 0; /* force an update of sk_pacing_rate */ + bbr_set_pacing_rate(sk, bw, bbr_high_gain); + + bbr->restore_cwnd = 0; + bbr->round_start = 0; + bbr->idle_restart = 0; + bbr->full_bw = 0; + bbr->full_bw_cnt = 0; + bbr->cycle_mstamp.v64 = 0; + bbr->cycle_idx = 0; + bbr_reset_lt_bw_sampling(sk); + bbr_reset_startup_mode(sk); +} + +static u32 bbr_sndbuf_expand(struct sock *sk) +{ + /* Provision 3 * cwnd since BBR may slow-start even during recovery. */ + return 3; +} + +/* In theory BBR does not need to undo the cwnd since it does not + * always reduce cwnd on losses (see bbr_main()). Keep it for now. + */ +static u32 bbr_undo_cwnd(struct sock *sk) +{ + return tcp_sk(sk)->snd_cwnd; +} + +/* Entering loss recovery, so save cwnd for when we exit or undo recovery. */ +static u32 bbr_ssthresh(struct sock *sk) +{ + bbr_save_cwnd(sk); + return TCP_INFINITE_SSTHRESH; /* BBR does not use ssthresh */ +} + +static size_t bbr_get_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + if (ext & (1 << (INET_DIAG_BBRINFO - 1)) || + ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 bw = bbr_bw(sk); + + bw = bw * tp->mss_cache * USEC_PER_SEC >> BW_SCALE; + memset(&info->bbr, 0, sizeof(info->bbr)); + info->bbr.bbr_bw_lo = (u32)bw; + info->bbr.bbr_bw_hi = (u32)(bw >> 32); + info->bbr.bbr_min_rtt = bbr->min_rtt_us; + info->bbr.bbr_pacing_gain = bbr->pacing_gain; + info->bbr.bbr_cwnd_gain = bbr->cwnd_gain; + *attr = INET_DIAG_BBRINFO; + return sizeof(info->bbr); + } + return 0; +} + +static void bbr_set_state(struct sock *sk, u8 new_state) +{ + struct bbr *bbr = inet_csk_ca(sk); + + if (new_state == TCP_CA_Loss) { + struct rate_sample rs = { .losses = 1 }; + + bbr->prev_ca_state = TCP_CA_Loss; + bbr->full_bw = 0; + bbr->round_start = 1; /* treat RTO like end of a round */ + bbr_lt_bw_sampling(sk, &rs); + } +} + +static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = { + .flags = TCP_CONG_NON_RESTRICTED, + .name = "bbr", + .owner = THIS_MODULE, + .init = bbr_init, + .cong_control = bbr_main, + .sndbuf_expand = bbr_sndbuf_expand, + .undo_cwnd = bbr_undo_cwnd, + .cwnd_event = bbr_cwnd_event, + .ssthresh = bbr_ssthresh, + .tso_segs_goal = bbr_tso_segs_goal, + .get_info = bbr_get_info, + .set_state = bbr_set_state, +}; + +static int __init bbr_register(void) +{ + BUILD_BUG_ON(sizeof(struct bbr) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_bbr_cong_ops); +} + +static void __exit bbr_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_bbr_cong_ops); +} + +module_init(bbr_register); +module_exit(bbr_unregister); + +MODULE_AUTHOR("Van Jacobson <vanj@google.com>"); +MODULE_AUTHOR("Neal Cardwell <ncardwell@google.com>"); +MODULE_AUTHOR("Yuchung Cheng <ycheng@google.com>"); +MODULE_AUTHOR("Soheil Hassas Yeganeh <soheil@google.com>"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_DESCRIPTION("TCP BBR (Bottleneck Bandwidth and RTT)"); diff --git a/net/ipv4/tcp_cdg.c b/net/ipv4/tcp_cdg.c index 03725b2..35b2803 100644 --- a/net/ipv4/tcp_cdg.c +++ b/net/ipv4/tcp_cdg.c @@ -56,7 +56,7 @@ MODULE_PARM_DESC(use_shadow, "use shadow window heuristic"); module_param(use_tolerance, bool, 0644); MODULE_PARM_DESC(use_tolerance, "use loss tolerance heuristic"); -struct minmax { +struct cdg_minmax { union { struct { s32 min; @@ -74,10 +74,10 @@ enum cdg_state { }; struct cdg { - struct minmax rtt; - struct minmax rtt_prev; - struct minmax *gradients; - struct minmax gsum; + struct cdg_minmax rtt; + struct cdg_minmax rtt_prev; + struct cdg_minmax *gradients; + struct cdg_minmax gsum; bool gfilled; u8 tail; u8 state; @@ -353,7 +353,7 @@ static void tcp_cdg_cwnd_event(struct sock *sk, const enum tcp_ca_event ev) { struct cdg *ca = inet_csk_ca(sk); struct tcp_sock *tp = tcp_sk(sk); - struct minmax *gradients; + struct cdg_minmax *gradients; switch (ev) { case CA_EVENT_CWND_RESTART: diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index 882caa4..1294af4 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -69,7 +69,7 @@ int tcp_register_congestion_control(struct tcp_congestion_ops *ca) int ret = 0; /* all algorithms must implement ssthresh and cong_avoid ops */ - if (!ca->ssthresh || !ca->cong_avoid) { + if (!ca->ssthresh || !(ca->cong_avoid || ca->cong_control)) { pr_err("%s does not implement required ops\n", ca->name); return -EINVAL; } diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index dad3e7e..a27b9c0 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -289,6 +289,7 @@ static bool tcp_ecn_rcv_ecn_echo(const struct tcp_sock *tp, const struct tcphdr static void tcp_sndbuf_expand(struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; int sndmem, per_mss; u32 nr_segs; @@ -309,7 +310,8 @@ static void tcp_sndbuf_expand(struct sock *sk) * Cubic needs 1.7 factor, rounded to 2 to include * extra cushion (application might react slowly to POLLOUT) */ - sndmem = 2 * nr_segs * per_mss; + sndmem = ca_ops->sndbuf_expand ? ca_ops->sndbuf_expand(sk) : 2; + sndmem *= nr_segs * per_mss; if (sk->sk_sndbuf < sndmem) sk->sk_sndbuf = min(sndmem, sysctl_tcp_wmem[2]); @@ -899,12 +901,29 @@ static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb) tp->retransmit_high = TCP_SKB_CB(skb)->end_seq; } +/* Sum the number of packets on the wire we have marked as lost. + * There are two cases we care about here: + * a) Packet hasn't been marked lost (nor retransmitted), + * and this is the first loss. + * b) Packet has been marked both lost and retransmitted, + * and this means we think it was lost again. + */ +static void tcp_sum_lost(struct tcp_sock *tp, struct sk_buff *skb) +{ + __u8 sacked = TCP_SKB_CB(skb)->sacked; + + if (!(sacked & TCPCB_LOST) || + ((sacked & TCPCB_LOST) && (sacked & TCPCB_SACKED_RETRANS))) + tp->lost += tcp_skb_pcount(skb); +} + static void tcp_skb_mark_lost(struct tcp_sock *tp, struct sk_buff *skb) { if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) { tcp_verify_retransmit_hint(tp, skb); tp->lost_out += tcp_skb_pcount(skb); + tcp_sum_lost(tp, skb); TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; } } @@ -913,6 +932,7 @@ void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb) { tcp_verify_retransmit_hint(tp, skb); + tcp_sum_lost(tp, skb); if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) { tp->lost_out += tcp_skb_pcount(skb); TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; @@ -1094,6 +1114,7 @@ struct tcp_sacktag_state { */ struct skb_mstamp first_sackt; struct skb_mstamp last_sackt; + struct rate_sample *rate; int flag; }; @@ -1261,6 +1282,7 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb, tcp_sacktag_one(sk, state, TCP_SKB_CB(skb)->sacked, start_seq, end_seq, dup_sack, pcount, &skb->skb_mstamp); + tcp_rate_skb_delivered(sk, skb, state->rate); if (skb == tp->lost_skb_hint) tp->lost_cnt_hint += pcount; @@ -1311,6 +1333,9 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb, tcp_advance_highest_sack(sk, skb); tcp_skb_collapse_tstamp(prev, skb); + if (unlikely(TCP_SKB_CB(prev)->tx.delivered_mstamp.v64)) + TCP_SKB_CB(prev)->tx.delivered_mstamp.v64 = 0; + tcp_unlink_write_queue(skb, sk); sk_wmem_free_skb(sk, skb); @@ -1540,6 +1565,7 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk, dup_sack, tcp_skb_pcount(skb), &skb->skb_mstamp); + tcp_rate_skb_delivered(sk, skb, state->rate); if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) @@ -1622,8 +1648,10 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb, found_dup_sack = tcp_check_dsack(sk, ack_skb, sp_wire, num_sacks, prior_snd_una); - if (found_dup_sack) + if (found_dup_sack) { state->flag |= FLAG_DSACKING_ACK; + tp->delivered++; /* A spurious retransmission is delivered */ + } /* Eliminate too old ACKs, but take into * account more or less fresh ones, they can @@ -1890,6 +1918,7 @@ void tcp_enter_loss(struct sock *sk) struct sk_buff *skb; bool new_recovery = icsk->icsk_ca_state < TCP_CA_Recovery; bool is_reneg; /* is receiver reneging on SACKs? */ + bool mark_lost; /* Reduce ssthresh if it has not yet been made inside this window. */ if (icsk->icsk_ca_state <= TCP_CA_Disorder || @@ -1923,8 +1952,12 @@ void tcp_enter_loss(struct sock *sk) if (skb == tcp_send_head(sk)) break; + mark_lost = (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) || + is_reneg); + if (mark_lost) + tcp_sum_lost(tp, skb); TCP_SKB_CB(skb)->sacked &= (~TCPCB_TAGBITS)|TCPCB_SACKED_ACKED; - if (!(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED) || is_reneg) { + if (mark_lost) { TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED; TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); @@ -2329,10 +2362,9 @@ static void DBGUNDO(struct sock *sk, const char *msg) } #if IS_ENABLED(CONFIG_IPV6) else if (sk->sk_family == AF_INET6) { - struct ipv6_pinfo *np = inet6_sk(sk); pr_debug("Undo %s %pI6/%u c%u l%u ss%u/%u p%u\n", msg, - &np->daddr, ntohs(inet->inet_dport), + &sk->sk_v6_daddr, ntohs(inet->inet_dport), tp->snd_cwnd, tcp_left_out(tp), tp->snd_ssthresh, tp->prior_ssthresh, tp->packets_out); @@ -2503,6 +2535,9 @@ static inline void tcp_end_cwnd_reduction(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); + if (inet_csk(sk)->icsk_ca_ops->cong_control) + return; + /* Reset cwnd to ssthresh in CWR or Recovery (unless it's undone) */ if (inet_csk(sk)->icsk_ca_state == TCP_CA_CWR || (tp->undo_marker && tp->snd_ssthresh < TCP_INFINITE_SSTHRESH)) { @@ -2879,67 +2914,13 @@ static void tcp_fastretrans_alert(struct sock *sk, const int acked, *rexmit = REXMIT_LOST; } -/* Kathleen Nichols' algorithm for tracking the minimum value of - * a data stream over some fixed time interval. (E.g., the minimum - * RTT over the past five minutes.) It uses constant space and constant - * time per update yet almost always delivers the same minimum as an - * implementation that has to keep all the data in the window. - * - * The algorithm keeps track of the best, 2nd best & 3rd best min - * values, maintaining an invariant that the measurement time of the - * n'th best >= n-1'th best. It also makes sure that the three values - * are widely separated in the time window since that bounds the worse - * case error when that data is monotonically increasing over the window. - * - * Upon getting a new min, we can forget everything earlier because it - * has no value - the new min is <= everything else in the window by - * definition and it's the most recent. So we restart fresh on every new min - * and overwrites 2nd & 3rd choices. The same property holds for 2nd & 3rd - * best. - */ static void tcp_update_rtt_min(struct sock *sk, u32 rtt_us) { - const u32 now = tcp_time_stamp, wlen = sysctl_tcp_min_rtt_wlen * HZ; - struct rtt_meas *m = tcp_sk(sk)->rtt_min; - struct rtt_meas rttm = { - .rtt = likely(rtt_us) ? rtt_us : jiffies_to_usecs(1), - .ts = now, - }; - u32 elapsed; - - /* Check if the new measurement updates the 1st, 2nd, or 3rd choices */ - if (unlikely(rttm.rtt <= m[0].rtt)) - m[0] = m[1] = m[2] = rttm; - else if (rttm.rtt <= m[1].rtt) - m[1] = m[2] = rttm; - else if (rttm.rtt <= m[2].rtt) - m[2] = rttm; - - elapsed = now - m[0].ts; - if (unlikely(elapsed > wlen)) { - /* Passed entire window without a new min so make 2nd choice - * the new min & 3rd choice the new 2nd. So forth and so on. - */ - m[0] = m[1]; - m[1] = m[2]; - m[2] = rttm; - if (now - m[0].ts > wlen) { - m[0] = m[1]; - m[1] = rttm; - if (now - m[0].ts > wlen) - m[0] = rttm; - } - } else if (m[1].ts == m[0].ts && elapsed > wlen / 4) { - /* Passed a quarter of the window without a new min so - * take 2nd choice from the 2nd quarter of the window. - */ - m[2] = m[1] = rttm; - } else if (m[2].ts == m[1].ts && elapsed > wlen / 2) { - /* Passed half the window without a new min so take the 3rd - * choice from the last half of the window. - */ - m[2] = rttm; - } + struct tcp_sock *tp = tcp_sk(sk); + u32 wlen = sysctl_tcp_min_rtt_wlen * HZ; + + minmax_running_min(&tp->rtt_min, wlen, tcp_time_stamp, + rtt_us ? : jiffies_to_usecs(1)); } static inline bool tcp_ack_update_rtt(struct sock *sk, const int flag, @@ -3102,10 +3083,11 @@ static void tcp_ack_tstamp(struct sock *sk, struct sk_buff *skb, */ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, u32 prior_snd_una, int *acked, - struct tcp_sacktag_state *sack) + struct tcp_sacktag_state *sack, + struct skb_mstamp *now) { const struct inet_connection_sock *icsk = inet_csk(sk); - struct skb_mstamp first_ackt, last_ackt, now; + struct skb_mstamp first_ackt, last_ackt; struct tcp_sock *tp = tcp_sk(sk); u32 prior_sacked = tp->sacked_out; u32 reord = tp->packets_out; @@ -3137,7 +3119,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, acked_pcount = tcp_tso_acked(sk, skb); if (!acked_pcount) break; - fully_acked = false; } else { /* Speedup tcp_unlink_write_queue() and next loop */ @@ -3173,6 +3154,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, tp->packets_out -= acked_pcount; pkts_acked += acked_pcount; + tcp_rate_skb_delivered(sk, skb, sack->rate); /* Initial outgoing SYN's get put onto the write_queue * just like anything else we transmit. It is not @@ -3205,16 +3187,15 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) flag |= FLAG_SACK_RENEGING; - skb_mstamp_get(&now); if (likely(first_ackt.v64) && !(flag & FLAG_RETRANS_DATA_ACKED)) { - seq_rtt_us = skb_mstamp_us_delta(&now, &first_ackt); - ca_rtt_us = skb_mstamp_us_delta(&now, &last_ackt); + seq_rtt_us = skb_mstamp_us_delta(now, &first_ackt); + ca_rtt_us = skb_mstamp_us_delta(now, &last_ackt); } if (sack->first_sackt.v64) { - sack_rtt_us = skb_mstamp_us_delta(&now, &sack->first_sackt); - ca_rtt_us = skb_mstamp_us_delta(&now, &sack->last_sackt); + sack_rtt_us = skb_mstamp_us_delta(now, &sack->first_sackt); + ca_rtt_us = skb_mstamp_us_delta(now, &sack->last_sackt); } - + sack->rate->rtt_us = ca_rtt_us; /* RTT of last (S)ACKed packet, or -1 */ rtt_update = tcp_ack_update_rtt(sk, flag, seq_rtt_us, sack_rtt_us, ca_rtt_us); @@ -3242,7 +3223,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, tp->fackets_out -= min(pkts_acked, tp->fackets_out); } else if (skb && rtt_update && sack_rtt_us >= 0 && - sack_rtt_us > skb_mstamp_us_delta(&now, &skb->skb_mstamp)) { + sack_rtt_us > skb_mstamp_us_delta(now, &skb->skb_mstamp)) { /* Do not re-arm RTO if the sack RTT is measured from data sent * after when the head was last (re)transmitted. Otherwise the * timeout may continue to extend in loss recovery. @@ -3333,8 +3314,15 @@ static inline bool tcp_may_raise_cwnd(const struct sock *sk, const int flag) * information. All transmission or retransmission are delayed afterwards. */ static void tcp_cong_control(struct sock *sk, u32 ack, u32 acked_sacked, - int flag) + int flag, const struct rate_sample *rs) { + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ca_ops->cong_control) { + icsk->icsk_ca_ops->cong_control(sk, rs); + return; + } + if (tcp_in_cwnd_reduction(sk)) { /* Reduce cwnd if state mandates */ tcp_cwnd_reduction(sk, acked_sacked, flag); @@ -3579,17 +3567,21 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); struct tcp_sacktag_state sack_state; + struct rate_sample rs = { .prior_delivered = 0 }; u32 prior_snd_una = tp->snd_una; u32 ack_seq = TCP_SKB_CB(skb)->seq; u32 ack = TCP_SKB_CB(skb)->ack_seq; bool is_dupack = false; u32 prior_fackets; int prior_packets = tp->packets_out; - u32 prior_delivered = tp->delivered; + u32 delivered = tp->delivered; + u32 lost = tp->lost; int acked = 0; /* Number of packets newly acked */ int rexmit = REXMIT_NONE; /* Flag to (re)transmit to recover losses */ + struct skb_mstamp now; sack_state.first_sackt.v64 = 0; + sack_state.rate = &rs; /* We very likely will need to access write queue head. */ prefetchw(sk->sk_write_queue.next); @@ -3612,6 +3604,8 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) if (after(ack, tp->snd_nxt)) goto invalid_ack; + skb_mstamp_get(&now); + if (icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS || icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) tcp_rearm_rto(sk); @@ -3622,6 +3616,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) } prior_fackets = tp->fackets_out; + rs.prior_in_flight = tcp_packets_in_flight(tp); /* ts_recent update must be made after we are sure that the packet * is in window. @@ -3677,7 +3672,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) /* See if we can take anything off of the retransmit queue. */ flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una, &acked, - &sack_state); + &sack_state, &now); if (tcp_ack_is_dubious(sk, flag)) { is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP)); @@ -3694,7 +3689,10 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) if (icsk->icsk_pending == ICSK_TIME_RETRANS) tcp_schedule_loss_probe(sk); - tcp_cong_control(sk, ack, tp->delivered - prior_delivered, flag); + delivered = tp->delivered - delivered; /* freshly ACKed or SACKed */ + lost = tp->lost - lost; /* freshly marked lost */ + tcp_rate_gen(sk, delivered, lost, &now, &rs); + tcp_cong_control(sk, ack, delivered, flag, &rs); tcp_xmit_recovery(sk, rexmit); return 1; @@ -5951,7 +5949,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) * so release it. */ if (req) { - tp->total_retrans = req->num_retrans; + inet_csk(sk)->icsk_retransmits = 0; reqsk_fastopen_remove(sk, req, false); } else { /* Make sure socket is routed, for correct metrics. */ @@ -5993,7 +5991,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) } else tcp_init_metrics(sk); - tcp_update_pacing_rate(sk); + if (!inet_csk(sk)->icsk_ca_ops->cong_control) + tcp_update_pacing_rate(sk); /* Prevent spurious tcp_cwnd_restart() on first data packet */ tp->lsndtime = tcp_time_stamp; @@ -6326,6 +6325,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; tcp_openreq_init(req, &tmp_opt, skb, sk); + inet_rsk(req)->no_srccheck = inet_sk(sk)->transparent; /* Note: tcp_v6_init_req() might override ir_iif for link locals */ inet_rsk(req)->ir_iif = inet_request_bound_dev_if(sk, skb); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 04b9893..7ac37c3 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1196,7 +1196,6 @@ static void tcp_v4_init_req(struct request_sock *req, sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); - ireq->no_srccheck = inet_sk(sk_listener)->transparent; ireq->opt = tcp_v4_save_options(skb); } diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index f63c73d..6234eba 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -464,7 +464,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, newtp->srtt_us = 0; newtp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); - newtp->rtt_min[0].rtt = ~0U; + minmax_reset(&newtp->rtt_min, tcp_time_stamp, ~0U); newicsk->icsk_rto = TCP_TIMEOUT_INIT; newtp->packets_out = 0; @@ -487,6 +487,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, newtp->snd_cwnd = TCP_INIT_CWND; newtp->snd_cwnd_cnt = 0; + /* There's a bubble in the pipe until at least the first ACK. */ + newtp->app_limited = ~0U; + tcp_init_xmit_timers(newsk); newtp->write_seq = newtp->pushed_seq = treq->snt_isn + 1; diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index 5c59649..bc68da3 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -90,12 +90,6 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb, goto out; } - /* GSO partial only requires splitting the frame into an MSS - * multiple and possibly a remainder. So update the mss now. - */ - if (features & NETIF_F_GSO_PARTIAL) - mss = skb->len - (skb->len % mss); - copy_destructor = gso_skb->destructor == tcp_wfree; ooo_okay = gso_skb->ooo_okay; /* All segments but the first should have ooo_okay cleared */ @@ -108,6 +102,13 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb, /* Only first segment might have ooo_okay set */ segs->ooo_okay = ooo_okay; + /* GSO partial and frag_list segmentation only requires splitting + * the frame into an MSS multiple and possibly a remainder, both + * cases return a GSO skb. So update the mss now. + */ + if (skb_is_gso(segs)) + mss *= skb_shinfo(segs)->gso_segs; + delta = htonl(oldlen + (thlen + mss)); skb = segs; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8b45794..896e9df 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -734,9 +734,16 @@ static void tcp_tsq_handler(struct sock *sk) { if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_CLOSING | - TCPF_CLOSE_WAIT | TCPF_LAST_ACK)) - tcp_write_xmit(sk, tcp_current_mss(sk), tcp_sk(sk)->nonagle, + TCPF_CLOSE_WAIT | TCPF_LAST_ACK)) { + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->lost_out > tp->retrans_out && + tp->snd_cwnd > tcp_packets_in_flight(tp)) + tcp_xmit_retransmit_queue(sk); + + tcp_write_xmit(sk, tcp_current_mss(sk), tp->nonagle, 0, GFP_ATOMIC); + } } /* * One tasklet per cpu tries to send more skbs. @@ -918,6 +925,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, skb_mstamp_get(&skb->skb_mstamp); TCP_SKB_CB(skb)->tx.in_flight = TCP_SKB_CB(skb)->end_seq - tp->snd_una; + tcp_rate_skb_sent(sk, skb); if (unlikely(skb_cloned(skb))) skb = pskb_copy(skb, gfp_mask); @@ -1213,6 +1221,9 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, tcp_set_skb_tso_segs(skb, mss_now); tcp_set_skb_tso_segs(buff, mss_now); + /* Update delivered info for the new segment */ + TCP_SKB_CB(buff)->tx = TCP_SKB_CB(skb)->tx; + /* If this packet has been sent out already, we must * adjust the various packet counters. */ @@ -1358,6 +1369,7 @@ int tcp_mss_to_mtu(struct sock *sk, int mss) } return mtu; } +EXPORT_SYMBOL(tcp_mss_to_mtu); /* MTU probing init per socket */ void tcp_mtup_init(struct sock *sk) @@ -1545,7 +1557,8 @@ static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp, /* Return how many segs we'd like on a TSO packet, * to send one TSO packet per ms */ -static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now) +u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, + int min_tso_segs) { u32 bytes, segs; @@ -1557,10 +1570,23 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now) * This preserves ACK clocking and is consistent * with tcp_tso_should_defer() heuristic. */ - segs = max_t(u32, bytes / mss_now, sysctl_tcp_min_tso_segs); + segs = max_t(u32, bytes / mss_now, min_tso_segs); return min_t(u32, segs, sk->sk_gso_max_segs); } +EXPORT_SYMBOL(tcp_tso_autosize); + +/* Return the number of segments we want in the skb we are transmitting. + * See if congestion control module wants to decide; otherwise, autosize. + */ +static u32 tcp_tso_segs(struct sock *sk, unsigned int mss_now) +{ + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; + u32 tso_segs = ca_ops->tso_segs_goal ? ca_ops->tso_segs_goal(sk) : 0; + + return tso_segs ? : + tcp_tso_autosize(sk, mss_now, sysctl_tcp_min_tso_segs); +} /* Returns the portion of skb which can be sent right away */ static unsigned int tcp_mss_split_point(const struct sock *sk, @@ -1966,12 +1992,14 @@ static int tcp_mtu_probe(struct sock *sk) len = 0; tcp_for_write_queue_from_safe(skb, next, sk) { copy = min_t(int, skb->len, probe_size - len); - if (nskb->ip_summed) + if (nskb->ip_summed) { skb_copy_bits(skb, 0, skb_put(nskb, copy), copy); - else - nskb->csum = skb_copy_and_csum_bits(skb, 0, - skb_put(nskb, copy), - copy, nskb->csum); + } else { + __wsum csum = skb_copy_and_csum_bits(skb, 0, + skb_put(nskb, copy), + copy, 0); + nskb->csum = csum_block_add(nskb->csum, csum, len); + } if (skb->len <= copy) { /* We've eaten all the data from this skb. @@ -2020,6 +2048,39 @@ static int tcp_mtu_probe(struct sock *sk) return -1; } +/* TCP Small Queues : + * Control number of packets in qdisc/devices to two packets / or ~1 ms. + * (These limits are doubled for retransmits) + * This allows for : + * - better RTT estimation and ACK scheduling + * - faster recovery + * - high rates + * Alas, some drivers / subsystems require a fair amount + * of queued bytes to ensure line rate. + * One example is wifi aggregation (802.11 AMPDU) + */ +static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb, + unsigned int factor) +{ + unsigned int limit; + + limit = max(2 * skb->truesize, sk->sk_pacing_rate >> 10); + limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes); + limit <<= factor; + + if (atomic_read(&sk->sk_wmem_alloc) > limit) { + set_bit(TSQ_THROTTLED, &tcp_sk(sk)->tsq_flags); + /* It is possible TX completion already happened + * before we set TSQ_THROTTLED, so we must + * test again the condition. + */ + smp_mb__after_atomic(); + if (atomic_read(&sk->sk_wmem_alloc) > limit) + return true; + } + return false; +} + /* This routine writes packets to the network. It advances the * send_head. This happens as incoming acks open up the remote * window for us. @@ -2057,7 +2118,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, } } - max_segs = tcp_tso_autosize(sk, mss_now); + max_segs = tcp_tso_segs(sk, mss_now); while ((skb = tcp_send_head(sk))) { unsigned int limit; @@ -2106,29 +2167,8 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, unlikely(tso_fragment(sk, skb, limit, mss_now, gfp))) break; - /* TCP Small Queues : - * Control number of packets in qdisc/devices to two packets / or ~1 ms. - * This allows for : - * - better RTT estimation and ACK scheduling - * - faster recovery - * - high rates - * Alas, some drivers / subsystems require a fair amount - * of queued bytes to ensure line rate. - * One example is wifi aggregation (802.11 AMPDU) - */ - limit = max(2 * skb->truesize, sk->sk_pacing_rate >> 10); - limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes); - - if (atomic_read(&sk->sk_wmem_alloc) > limit) { - set_bit(TSQ_THROTTLED, &tp->tsq_flags); - /* It is possible TX completion already happened - * before we set TSQ_THROTTLED, so we must - * test again the condition. - */ - smp_mb__after_atomic(); - if (atomic_read(&sk->sk_wmem_alloc) > limit) - break; - } + if (tcp_small_queue_check(sk, skb, 0)) + break; if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp))) break; @@ -2605,7 +2645,8 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) * copying overhead: fragmentation, tunneling, mangling etc. */ if (atomic_read(&sk->sk_wmem_alloc) > - min(sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), sk->sk_sndbuf)) + min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), + sk->sk_sndbuf)) return -EAGAIN; if (skb_still_in_host_queue(sk, skb)) @@ -2774,7 +2815,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) last_lost = tp->snd_una; } - max_segs = tcp_tso_autosize(sk, tcp_current_mss(sk)); + max_segs = tcp_tso_segs(sk, tcp_current_mss(sk)); tcp_for_write_queue_from(skb, sk) { __u8 sacked; int segs; @@ -2828,10 +2869,13 @@ begin_fwd: if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS)) continue; + if (tcp_small_queue_check(sk, skb, 1)) + return; + if (tcp_retransmit_skb(sk, skb, segs)) return; - NET_INC_STATS(sock_net(sk), mib_idx); + NET_ADD_STATS(sock_net(sk), mib_idx, tcp_skb_pcount(skb)); if (tcp_in_cwnd_reduction(sk)) tp->prr_out += tcp_skb_pcount(skb); @@ -3568,6 +3612,8 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req) if (!res) { __TCP_INC_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS); __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); + if (unlikely(tcp_passive_fastopen(sk))) + tcp_sk(sk)->total_retrans++; } return res; } diff --git a/net/ipv4/tcp_rate.c b/net/ipv4/tcp_rate.c new file mode 100644 index 0000000..9be1581 --- /dev/null +++ b/net/ipv4/tcp_rate.c @@ -0,0 +1,186 @@ +#include <net/tcp.h> + +/* The bandwidth estimator estimates the rate at which the network + * can currently deliver outbound data packets for this flow. At a high + * level, it operates by taking a delivery rate sample for each ACK. + * + * A rate sample records the rate at which the network delivered packets + * for this flow, calculated over the time interval between the transmission + * of a data packet and the acknowledgment of that packet. + * + * Specifically, over the interval between each transmit and corresponding ACK, + * the estimator generates a delivery rate sample. Typically it uses the rate + * at which packets were acknowledged. However, the approach of using only the + * acknowledgment rate faces a challenge under the prevalent ACK decimation or + * compression: packets can temporarily appear to be delivered much quicker + * than the bottleneck rate. Since it is physically impossible to do that in a + * sustained fashion, when the estimator notices that the ACK rate is faster + * than the transmit rate, it uses the latter: + * + * send_rate = #pkts_delivered/(last_snd_time - first_snd_time) + * ack_rate = #pkts_delivered/(last_ack_time - first_ack_time) + * bw = min(send_rate, ack_rate) + * + * Notice the estimator essentially estimates the goodput, not always the + * network bottleneck link rate when the sending or receiving is limited by + * other factors like applications or receiver window limits. The estimator + * deliberately avoids using the inter-packet spacing approach because that + * approach requires a large number of samples and sophisticated filtering. + * + * TCP flows can often be application-limited in request/response workloads. + * The estimator marks a bandwidth sample as application-limited if there + * was some moment during the sampled window of packets when there was no data + * ready to send in the write queue. + */ + +/* Snapshot the current delivery information in the skb, to generate + * a rate sample later when the skb is (s)acked in tcp_rate_skb_delivered(). + */ +void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* In general we need to start delivery rate samples from the + * time we received the most recent ACK, to ensure we include + * the full time the network needs to deliver all in-flight + * packets. If there are no packets in flight yet, then we + * know that any ACKs after now indicate that the network was + * able to deliver those packets completely in the sampling + * interval between now and the next ACK. + * + * Note that we use packets_out instead of tcp_packets_in_flight(tp) + * because the latter is a guess based on RTO and loss-marking + * heuristics. We don't want spurious RTOs or loss markings to cause + * a spuriously small time interval, causing a spuriously high + * bandwidth estimate. + */ + if (!tp->packets_out) { + tp->first_tx_mstamp = skb->skb_mstamp; + tp->delivered_mstamp = skb->skb_mstamp; + } + + TCP_SKB_CB(skb)->tx.first_tx_mstamp = tp->first_tx_mstamp; + TCP_SKB_CB(skb)->tx.delivered_mstamp = tp->delivered_mstamp; + TCP_SKB_CB(skb)->tx.delivered = tp->delivered; + TCP_SKB_CB(skb)->tx.is_app_limited = tp->app_limited ? 1 : 0; +} + +/* When an skb is sacked or acked, we fill in the rate sample with the (prior) + * delivery information when the skb was last transmitted. + * + * If an ACK (s)acks multiple skbs (e.g., stretched-acks), this function is + * called multiple times. We favor the information from the most recently + * sent skb, i.e., the skb with the highest prior_delivered count. + */ +void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, + struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_skb_cb *scb = TCP_SKB_CB(skb); + + if (!scb->tx.delivered_mstamp.v64) + return; + + if (!rs->prior_delivered || + after(scb->tx.delivered, rs->prior_delivered)) { + rs->prior_delivered = scb->tx.delivered; + rs->prior_mstamp = scb->tx.delivered_mstamp; + rs->is_app_limited = scb->tx.is_app_limited; + rs->is_retrans = scb->sacked & TCPCB_RETRANS; + + /* Find the duration of the "send phase" of this window: */ + rs->interval_us = skb_mstamp_us_delta( + &skb->skb_mstamp, + &scb->tx.first_tx_mstamp); + + /* Record send time of most recently ACKed packet: */ + tp->first_tx_mstamp = skb->skb_mstamp; + } + /* Mark off the skb delivered once it's sacked to avoid being + * used again when it's cumulatively acked. For acked packets + * we don't need to reset since it'll be freed soon. + */ + if (scb->sacked & TCPCB_SACKED_ACKED) + scb->tx.delivered_mstamp.v64 = 0; +} + +/* Update the connection delivery information and generate a rate sample. */ +void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, + struct skb_mstamp *now, struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 snd_us, ack_us; + + /* Clear app limited if bubble is acked and gone. */ + if (tp->app_limited && after(tp->delivered, tp->app_limited)) + tp->app_limited = 0; + + /* TODO: there are multiple places throughout tcp_ack() to get + * current time. Refactor the code using a new "tcp_acktag_state" + * to carry current time, flags, stats like "tcp_sacktag_state". + */ + if (delivered) + tp->delivered_mstamp = *now; + + rs->acked_sacked = delivered; /* freshly ACKed or SACKed */ + rs->losses = lost; /* freshly marked lost */ + /* Return an invalid sample if no timing information is available. */ + if (!rs->prior_mstamp.v64) { + rs->delivered = -1; + rs->interval_us = -1; + return; + } + rs->delivered = tp->delivered - rs->prior_delivered; + + /* Model sending data and receiving ACKs as separate pipeline phases + * for a window. Usually the ACK phase is longer, but with ACK + * compression the send phase can be longer. To be safe we use the + * longer phase. + */ + snd_us = rs->interval_us; /* send phase */ + ack_us = skb_mstamp_us_delta(now, &rs->prior_mstamp); /* ack phase */ + rs->interval_us = max(snd_us, ack_us); + + /* Normally we expect interval_us >= min-rtt. + * Note that rate may still be over-estimated when a spuriously + * retransmistted skb was first (s)acked because "interval_us" + * is under-estimated (up to an RTT). However continuously + * measuring the delivery rate during loss recovery is crucial + * for connections suffer heavy or prolonged losses. + */ + if (unlikely(rs->interval_us < tcp_min_rtt(tp))) { + if (!rs->is_retrans) + pr_debug("tcp rate: %ld %d %u %u %u\n", + rs->interval_us, rs->delivered, + inet_csk(sk)->icsk_ca_state, + tp->rx_opt.sack_ok, tcp_min_rtt(tp)); + rs->interval_us = -1; + return; + } + + /* Record the last non-app-limited or the highest app-limited bw */ + if (!rs->is_app_limited || + ((u64)rs->delivered * tp->rate_interval_us >= + (u64)tp->rate_delivered * rs->interval_us)) { + tp->rate_delivered = rs->delivered; + tp->rate_interval_us = rs->interval_us; + tp->rate_app_limited = rs->is_app_limited; + } +} + +/* If a gap is detected between sends, mark the socket application-limited. */ +void tcp_rate_check_app_limited(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (/* We have less than one packet to send. */ + tp->write_seq - tp->snd_nxt < tp->mss_cache && + /* Nothing in sending host's qdisc queues or NIC tx queue. */ + sk_wmem_alloc_get(sk) < SKB_TRUESIZE(1) && + /* We are not limited by CWND. */ + tcp_packets_in_flight(tp) < tp->snd_cwnd && + /* All lost packets have been retransmitted. */ + tp->lost_out <= tp->retrans_out) + tp->app_limited = + (tp->delivered + tcp_packets_in_flight(tp)) ? : 1; +} diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index d84930b..3ea1cf8 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -192,6 +192,8 @@ static int tcp_write_timeout(struct sock *sk) if (tp->syn_data && icsk->icsk_retransmits == 1) NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVEFAIL); + } else if (!tp->syn_data && !tp->syn_fastopen) { + sk_rethink_txhash(sk); } retry_until = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; syn_set = true; @@ -213,6 +215,8 @@ static int tcp_write_timeout(struct sock *sk) tcp_mtu_probing(icsk, sk); dst_negative_advice(sk); + } else { + sk_rethink_txhash(sk); } retry_until = net->ipv4.sysctl_tcp_retries2; @@ -384,6 +388,7 @@ static void tcp_fastopen_synack_timer(struct sock *sk) */ inet_rtx_syn_ack(sk, req); req->num_timeout++; + icsk->icsk_retransmits++; inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); } diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 81f253b..f9333c9 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -21,7 +21,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, __be16 new_protocol, bool is_ipv6) { int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); - bool remcsum, need_csum, offload_csum, ufo; + bool remcsum, need_csum, offload_csum, ufo, gso_partial; struct sk_buff *segs = ERR_PTR(-EINVAL); struct udphdr *uh = udp_hdr(skb); u16 mac_offset = skb->mac_header; @@ -88,6 +88,8 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, goto out; } + gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); + outer_hlen = skb_tnl_header_len(skb); udp_offset = outer_hlen - tnl_hlen; skb = segs; @@ -117,7 +119,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, * will be using a length value equal to only one MSS sized * segment instead of the entire frame. */ - if (skb_is_gso(skb)) { + if (gso_partial) { uh->len = htons(skb_shinfo(skb)->gso_size + SKB_GSO_CB(skb)->data_offset + skb->head - (unsigned char *)uh); |
