| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Toke Höiland-Jörgensen | 14375 | 96.17% | 18 | 40.91% |
| George Amanakis | 254 | 1.70% | 1 | 2.27% |
| Ilya Ponetayev | 108 | 0.72% | 1 | 2.27% |
| Kevin Darbyshire-Bryant | 90 | 0.60% | 3 | 6.82% |
| Dave Täht | 24 | 0.16% | 1 | 2.27% |
| Maxim Mikityanskiy | 20 | 0.13% | 1 | 2.27% |
| Jason A. Donenfeld | 11 | 0.07% | 3 | 6.82% |
| Victorien Molle | 11 | 0.07% | 1 | 2.27% |
| Zhengchao Shao | 10 | 0.07% | 2 | 4.55% |
| Eric Dumazet | 10 | 0.07% | 3 | 6.82% |
| David S. Miller | 9 | 0.06% | 1 | 2.27% |
| Michal Kubeček | 5 | 0.03% | 1 | 2.27% |
| Kevin Bracey | 5 | 0.03% | 1 | 2.27% |
| Wen Yang | 3 | 0.02% | 1 | 2.27% |
| Xin Long | 3 | 0.02% | 1 | 2.27% |
| Jaswinder Singh Rajput | 3 | 0.02% | 1 | 2.27% |
| Kees Cook | 2 | 0.01% | 1 | 2.27% |
| Gustavo A. R. Silva | 2 | 0.01% | 1 | 2.27% |
| Davide Caratti | 2 | 0.01% | 1 | 2.27% |
| Johannes Berg | 1 | 0.01% | 1 | 2.27% |
| Total | 14948 | 44 |
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* COMMON Applications Kept Enhanced (CAKE) discipline * * Copyright (C) 2014-2018 Jonathan Morton <chromatix99@gmail.com> * Copyright (C) 2015-2018 Toke Høiland-Jørgensen <toke@toke.dk> * Copyright (C) 2014-2018 Dave Täht <dave.taht@gmail.com> * Copyright (C) 2015-2018 Sebastian Moeller <moeller0@gmx.de> * (C) 2015-2018 Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk> * Copyright (C) 2017-2018 Ryan Mounce <ryan@mounce.com.au> * * The CAKE Principles: * (or, how to have your cake and eat it too) * * This is a combination of several shaping, AQM and FQ techniques into one * easy-to-use package: * * - An overall bandwidth shaper, to move the bottleneck away from dumb CPE * equipment and bloated MACs. This operates in deficit mode (as in sch_fq), * eliminating the need for any sort of burst parameter (eg. token bucket * depth). Burst support is limited to that necessary to overcome scheduling * latency. * * - A Diffserv-aware priority queue, giving more priority to certain classes, * up to a specified fraction of bandwidth. Above that bandwidth threshold, * the priority is reduced to avoid starving other tins. * * - Each priority tin has a separate Flow Queue system, to isolate traffic * flows from each other. This prevents a burst on one flow from increasing * the delay to another. Flows are distributed to queues using a * set-associative hash function. * * - Each queue is actively managed by Cobalt, which is a combination of the * Codel and Blue AQM algorithms. This serves flows fairly, and signals * congestion early via ECN (if available) and/or packet drops, to keep * latency low. The codel parameters are auto-tuned based on the bandwidth * setting, as is necessary at low bandwidths. * * The configuration parameters are kept deliberately simple for ease of use. * Everything has sane defaults. Complete generality of configuration is *not* * a goal. * * The priority queue operates according to a weighted DRR scheme, combined with * a bandwidth tracker which reuses the shaper logic to detect which side of the * bandwidth sharing threshold the tin is operating. This determines whether a * priority-based weight (high) or a bandwidth-based weight (low) is used for * that tin in the current pass. * * This qdisc was inspired by Eric Dumazet's fq_codel code, which he kindly * granted us permission to leverage. */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/jiffies.h> #include <linux/string.h> #include <linux/in.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/skbuff.h> #include <linux/jhash.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/reciprocal_div.h> #include <net/netlink.h> #include <linux/if_vlan.h> #include <net/gso.h> #include <net/pkt_sched.h> #include <net/pkt_cls.h> #include <net/tcp.h> #include <net/flow_dissector.h> #if IS_ENABLED(CONFIG_NF_CONNTRACK) #include <net/netfilter/nf_conntrack_core.h> #endif #define CAKE_SET_WAYS (8) #define CAKE_MAX_TINS (8) #define CAKE_QUEUES (1024) #define CAKE_FLOW_MASK 63 #define CAKE_FLOW_NAT_FLAG 64 /* struct cobalt_params - contains codel and blue parameters * @interval: codel initial drop rate * @target: maximum persistent sojourn time & blue update rate * @mtu_time: serialisation delay of maximum-size packet * @p_inc: increment of blue drop probability (0.32 fxp) * @p_dec: decrement of blue drop probability (0.32 fxp) */ struct cobalt_params { u64 interval; u64 target; u64 mtu_time; u32 p_inc; u32 p_dec; }; /* struct cobalt_vars - contains codel and blue variables * @count: codel dropping frequency * @rec_inv_sqrt: reciprocal value of sqrt(count) >> 1 * @drop_next: time to drop next packet, or when we dropped last * @blue_timer: Blue time to next drop * @p_drop: BLUE drop probability (0.32 fxp) * @dropping: set if in dropping state * @ecn_marked: set if marked */ struct cobalt_vars { u32 count; u32 rec_inv_sqrt; ktime_t drop_next; ktime_t blue_timer; u32 p_drop; bool dropping; bool ecn_marked; }; enum { CAKE_SET_NONE = 0, CAKE_SET_SPARSE, CAKE_SET_SPARSE_WAIT, /* counted in SPARSE, actually in BULK */ CAKE_SET_BULK, CAKE_SET_DECAYING }; struct cake_flow { /* this stuff is all needed per-flow at dequeue time */ struct sk_buff *head; struct sk_buff *tail; struct list_head flowchain; s32 deficit; u32 dropped; struct cobalt_vars cvars; u16 srchost; /* index into cake_host table */ u16 dsthost; u8 set; }; /* please try to keep this structure <= 64 bytes */ struct cake_host { u32 srchost_tag; u32 dsthost_tag; u16 srchost_bulk_flow_count; u16 dsthost_bulk_flow_count; }; struct cake_heap_entry { u16 t:3, b:10; }; struct cake_tin_data { struct cake_flow flows[CAKE_QUEUES]; u32 backlogs[CAKE_QUEUES]; u32 tags[CAKE_QUEUES]; /* for set association */ u16 overflow_idx[CAKE_QUEUES]; struct cake_host hosts[CAKE_QUEUES]; /* for triple isolation */ u16 flow_quantum; struct cobalt_params cparams; u32 drop_overlimit; u16 bulk_flow_count; u16 sparse_flow_count; u16 decaying_flow_count; u16 unresponsive_flow_count; u32 max_skblen; struct list_head new_flows; struct list_head old_flows; struct list_head decaying_flows; /* time_next = time_this + ((len * rate_ns) >> rate_shft) */ ktime_t time_next_packet; u64 tin_rate_ns; u64 tin_rate_bps; u16 tin_rate_shft; u16 tin_quantum; s32 tin_deficit; u32 tin_backlog; u32 tin_dropped; u32 tin_ecn_mark; u32 packets; u64 bytes; u32 ack_drops; /* moving averages */ u64 avge_delay; u64 peak_delay; u64 base_delay; /* hash function stats */ u32 way_directs; u32 way_hits; u32 way_misses; u32 way_collisions; }; /* number of tins is small, so size of this struct doesn't matter much */ struct cake_sched_data { struct tcf_proto __rcu *filter_list; /* optional external classifier */ struct tcf_block *block; struct cake_tin_data *tins; struct cake_heap_entry overflow_heap[CAKE_QUEUES * CAKE_MAX_TINS]; u16 overflow_timeout; u16 tin_cnt; u8 tin_mode; u8 flow_mode; u8 ack_filter; u8 atm_mode; u32 fwmark_mask; u16 fwmark_shft; /* time_next = time_this + ((len * rate_ns) >> rate_shft) */ u16 rate_shft; ktime_t time_next_packet; ktime_t failsafe_next_packet; u64 rate_ns; u64 rate_bps; u16 rate_flags; s16 rate_overhead; u16 rate_mpu; u64 interval; u64 target; /* resource tracking */ u32 buffer_used; u32 buffer_max_used; u32 buffer_limit; u32 buffer_config_limit; /* indices for dequeue */ u16 cur_tin; u16 cur_flow; struct qdisc_watchdog watchdog; const u8 *tin_index; const u8 *tin_order; /* bandwidth capacity estimate */ ktime_t last_packet_time; ktime_t avg_window_begin; u64 avg_packet_interval; u64 avg_window_bytes; u64 avg_peak_bandwidth; ktime_t last_reconfig_time; /* packet length stats */ u32 avg_netoff; u16 max_netlen; u16 max_adjlen; u16 min_netlen; u16 min_adjlen; }; enum { CAKE_FLAG_OVERHEAD = BIT(0), CAKE_FLAG_AUTORATE_INGRESS = BIT(1), CAKE_FLAG_INGRESS = BIT(2), CAKE_FLAG_WASH = BIT(3), CAKE_FLAG_SPLIT_GSO = BIT(4) }; /* COBALT operates the Codel and BLUE algorithms in parallel, in order to * obtain the best features of each. Codel is excellent on flows which * respond to congestion signals in a TCP-like way. BLUE is more effective on * unresponsive flows. */ struct cobalt_skb_cb { ktime_t enqueue_time; u32 adjusted_len; }; static u64 us_to_ns(u64 us) { return us * NSEC_PER_USEC; } static struct cobalt_skb_cb *get_cobalt_cb(const struct sk_buff *skb) { qdisc_cb_private_validate(skb, sizeof(struct cobalt_skb_cb)); return (struct cobalt_skb_cb *)qdisc_skb_cb(skb)->data; } static ktime_t cobalt_get_enqueue_time(const struct sk_buff *skb) { return get_cobalt_cb(skb)->enqueue_time; } static void cobalt_set_enqueue_time(struct sk_buff *skb, ktime_t now) { get_cobalt_cb(skb)->enqueue_time = now; } static u16 quantum_div[CAKE_QUEUES + 1] = {0}; /* Diffserv lookup tables */ static const u8 precedence[] = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, }; static const u8 diffserv8[] = { 2, 0, 1, 2, 4, 2, 2, 2, 1, 2, 1, 2, 1, 2, 1, 2, 5, 2, 4, 2, 4, 2, 4, 2, 3, 2, 3, 2, 3, 2, 3, 2, 6, 2, 3, 2, 3, 2, 3, 2, 6, 2, 2, 2, 6, 2, 6, 2, 7, 2, 2, 2, 2, 2, 2, 2, 7, 2, 2, 2, 2, 2, 2, 2, }; static const u8 diffserv4[] = { 0, 1, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 3, 0, 2, 0, 2, 0, 2, 0, 3, 0, 0, 0, 3, 0, 3, 0, 3, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, }; static const u8 diffserv3[] = { 0, 1, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, }; static const u8 besteffort[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }; /* tin priority order for stats dumping */ static const u8 normal_order[] = {0, 1, 2, 3, 4, 5, 6, 7}; static const u8 bulk_order[] = {1, 0, 2, 3}; #define REC_INV_SQRT_CACHE (16) static u32 cobalt_rec_inv_sqrt_cache[REC_INV_SQRT_CACHE] = {0}; /* http://en.wikipedia.org/wiki/Methods_of_computing_square_roots * new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2) * * Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32 */ static void cobalt_newton_step(struct cobalt_vars *vars) { u32 invsqrt, invsqrt2; u64 val; invsqrt = vars->rec_inv_sqrt; invsqrt2 = ((u64)invsqrt * invsqrt) >> 32; val = (3LL << 32) - ((u64)vars->count * invsqrt2); val >>= 2; /* avoid overflow in following multiply */ val = (val * invsqrt) >> (32 - 2 + 1); vars->rec_inv_sqrt = val; } static void cobalt_invsqrt(struct cobalt_vars *vars) { if (vars->count < REC_INV_SQRT_CACHE) vars->rec_inv_sqrt = cobalt_rec_inv_sqrt_cache[vars->count]; else cobalt_newton_step(vars); } /* There is a big difference in timing between the accurate values placed in * the cache and the approximations given by a single Newton step for small * count values, particularly when stepping from count 1 to 2 or vice versa. * Above 16, a single Newton step gives sufficient accuracy in either * direction, given the precision stored. * * The magnitude of the error when stepping up to count 2 is such as to give * the value that *should* have been produced at count 4. */ static void cobalt_cache_init(void) { struct cobalt_vars v; memset(&v, 0, sizeof(v)); v.rec_inv_sqrt = ~0U; cobalt_rec_inv_sqrt_cache[0] = v.rec_inv_sqrt; for (v.count = 1; v.count < REC_INV_SQRT_CACHE; v.count++) { cobalt_newton_step(&v); cobalt_newton_step(&v); cobalt_newton_step(&v); cobalt_newton_step(&v); cobalt_rec_inv_sqrt_cache[v.count] = v.rec_inv_sqrt; } } static void cobalt_vars_init(struct cobalt_vars *vars) { memset(vars, 0, sizeof(*vars)); if (!cobalt_rec_inv_sqrt_cache[0]) { cobalt_cache_init(); cobalt_rec_inv_sqrt_cache[0] = ~0; } } /* CoDel control_law is t + interval/sqrt(count) * We maintain in rec_inv_sqrt the reciprocal value of sqrt(count) to avoid * both sqrt() and divide operation. */ static ktime_t cobalt_control(ktime_t t, u64 interval, u32 rec_inv_sqrt) { return ktime_add_ns(t, reciprocal_scale(interval, rec_inv_sqrt)); } /* Call this when a packet had to be dropped due to queue overflow. Returns * true if the BLUE state was quiescent before but active after this call. */ static bool cobalt_queue_full(struct cobalt_vars *vars, struct cobalt_params *p, ktime_t now) { bool up = false; if (ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) { up = !vars->p_drop; vars->p_drop += p->p_inc; if (vars->p_drop < p->p_inc) vars->p_drop = ~0; vars->blue_timer = now; } vars->dropping = true; vars->drop_next = now; if (!vars->count) vars->count = 1; return up; } /* Call this when the queue was serviced but turned out to be empty. Returns * true if the BLUE state was active before but quiescent after this call. */ static bool cobalt_queue_empty(struct cobalt_vars *vars, struct cobalt_params *p, ktime_t now) { bool down = false; if (vars->p_drop && ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) { if (vars->p_drop < p->p_dec) vars->p_drop = 0; else vars->p_drop -= p->p_dec; vars->blue_timer = now; down = !vars->p_drop; } vars->dropping = false; if (vars->count && ktime_to_ns(ktime_sub(now, vars->drop_next)) >= 0) { vars->count--; cobalt_invsqrt(vars); vars->drop_next = cobalt_control(vars->drop_next, p->interval, vars->rec_inv_sqrt); } return down; } /* Call this with a freshly dequeued packet for possible congestion marking. * Returns true as an instruction to drop the packet, false for delivery. */ static bool cobalt_should_drop(struct cobalt_vars *vars, struct cobalt_params *p, ktime_t now, struct sk_buff *skb, u32 bulk_flows) { bool next_due, over_target, drop = false; ktime_t schedule; u64 sojourn; /* The 'schedule' variable records, in its sign, whether 'now' is before or * after 'drop_next'. This allows 'drop_next' to be updated before the next * scheduling decision is actually branched, without destroying that * information. Similarly, the first 'schedule' value calculated is preserved * in the boolean 'next_due'. * * As for 'drop_next', we take advantage of the fact that 'interval' is both * the delay between first exceeding 'target' and the first signalling event, * *and* the scaling factor for the signalling frequency. It's therefore very * natural to use a single mechanism for both purposes, and eliminates a * significant amount of reference Codel's spaghetti code. To help with this, * both the '0' and '1' entries in the invsqrt cache are 0xFFFFFFFF, as close * as possible to 1.0 in fixed-point. */ sojourn = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb))); schedule = ktime_sub(now, vars->drop_next); over_target = sojourn > p->target && sojourn > p->mtu_time * bulk_flows * 2 && sojourn > p->mtu_time * 4; next_due = vars->count && ktime_to_ns(schedule) >= 0; vars->ecn_marked = false; if (over_target) { if (!vars->dropping) { vars->dropping = true; vars->drop_next = cobalt_control(now, p->interval, vars->rec_inv_sqrt); } if (!vars->count) vars->count = 1; } else if (vars->dropping) { vars->dropping = false; } if (next_due && vars->dropping) { /* Use ECN mark if possible, otherwise drop */ drop = !(vars->ecn_marked = INET_ECN_set_ce(skb)); vars->count++; if (!vars->count) vars->count--; cobalt_invsqrt(vars); vars->drop_next = cobalt_control(vars->drop_next, p->interval, vars->rec_inv_sqrt); schedule = ktime_sub(now, vars->drop_next); } else { while (next_due) { vars->count--; cobalt_invsqrt(vars); vars->drop_next = cobalt_control(vars->drop_next, p->interval, vars->rec_inv_sqrt); schedule = ktime_sub(now, vars->drop_next); next_due = vars->count && ktime_to_ns(schedule) >= 0; } } /* Simple BLUE implementation. Lack of ECN is deliberate. */ if (vars->p_drop) drop |= (get_random_u32() < vars->p_drop); /* Overload the drop_next field as an activity timeout */ if (!vars->count) vars->drop_next = ktime_add_ns(now, p->interval); else if (ktime_to_ns(schedule) > 0 && !drop) vars->drop_next = now; return drop; } static bool cake_update_flowkeys(struct flow_keys *keys, const struct sk_buff *skb) { #if IS_ENABLED(CONFIG_NF_CONNTRACK) struct nf_conntrack_tuple tuple = {}; bool rev = !skb->_nfct, upd = false; __be32 ip; if (skb_protocol(skb, true) != htons(ETH_P_IP)) return false; if (!nf_ct_get_tuple_skb(&tuple, skb)) return false; ip = rev ? tuple.dst.u3.ip : tuple.src.u3.ip; if (ip != keys->addrs.v4addrs.src) { keys->addrs.v4addrs.src = ip; upd = true; } ip = rev ? tuple.src.u3.ip : tuple.dst.u3.ip; if (ip != keys->addrs.v4addrs.dst) { keys->addrs.v4addrs.dst = ip; upd = true; } if (keys->ports.ports) { __be16 port; port = rev ? tuple.dst.u.all : tuple.src.u.all; if (port != keys->ports.src) { keys->ports.src = port; upd = true; } port = rev ? tuple.src.u.all : tuple.dst.u.all; if (port != keys->ports.dst) { port = keys->ports.dst; upd = true; } } return upd; #else return false; #endif } /* Cake has several subtle multiple bit settings. In these cases you * would be matching triple isolate mode as well. */ static bool cake_dsrc(int flow_mode) { return (flow_mode & CAKE_FLOW_DUAL_SRC) == CAKE_FLOW_DUAL_SRC; } static bool cake_ddst(int flow_mode) { return (flow_mode & CAKE_FLOW_DUAL_DST) == CAKE_FLOW_DUAL_DST; } static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb, int flow_mode, u16 flow_override, u16 host_override) { bool hash_flows = (!flow_override && !!(flow_mode & CAKE_FLOW_FLOWS)); bool hash_hosts = (!host_override && !!(flow_mode & CAKE_FLOW_HOSTS)); bool nat_enabled = !!(flow_mode & CAKE_FLOW_NAT_FLAG); u32 flow_hash = 0, srchost_hash = 0, dsthost_hash = 0; u16 reduced_hash, srchost_idx, dsthost_idx; struct flow_keys keys, host_keys; bool use_skbhash = skb->l4_hash; if (unlikely(flow_mode == CAKE_FLOW_NONE)) return 0; /* If both overrides are set, or we can use the SKB hash and nat mode is * disabled, we can skip packet dissection entirely. If nat mode is * enabled there's another check below after doing the conntrack lookup. */ if ((!hash_flows || (use_skbhash && !nat_enabled)) && !hash_hosts) goto skip_hash; skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); /* Don't use the SKB hash if we change the lookup keys from conntrack */ if (nat_enabled && cake_update_flowkeys(&keys, skb)) use_skbhash = false; /* If we can still use the SKB hash and don't need the host hash, we can * skip the rest of the hashing procedure */ if (use_skbhash && !hash_hosts) goto skip_hash; /* flow_hash_from_keys() sorts the addresses by value, so we have * to preserve their order in a separate data structure to treat * src and dst host addresses as independently selectable. */ host_keys = keys; host_keys.ports.ports = 0; host_keys.basic.ip_proto = 0; host_keys.keyid.keyid = 0; host_keys.tags.flow_label = 0; switch (host_keys.control.addr_type) { case FLOW_DISSECTOR_KEY_IPV4_ADDRS: host_keys.addrs.v4addrs.src = 0; dsthost_hash = flow_hash_from_keys(&host_keys); host_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; host_keys.addrs.v4addrs.dst = 0; srchost_hash = flow_hash_from_keys(&host_keys); break; case FLOW_DISSECTOR_KEY_IPV6_ADDRS: memset(&host_keys.addrs.v6addrs.src, 0, sizeof(host_keys.addrs.v6addrs.src)); dsthost_hash = flow_hash_from_keys(&host_keys); host_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; memset(&host_keys.addrs.v6addrs.dst, 0, sizeof(host_keys.addrs.v6addrs.dst)); srchost_hash = flow_hash_from_keys(&host_keys); break; default: dsthost_hash = 0; srchost_hash = 0; } /* This *must* be after the above switch, since as a * side-effect it sorts the src and dst addresses. */ if (hash_flows && !use_skbhash) flow_hash = flow_hash_from_keys(&keys); skip_hash: if (flow_override) flow_hash = flow_override - 1; else if (use_skbhash && (flow_mode & CAKE_FLOW_FLOWS)) flow_hash = skb->hash; if (host_override) { dsthost_hash = host_override - 1; srchost_hash = host_override - 1; } if (!(flow_mode & CAKE_FLOW_FLOWS)) { if (flow_mode & CAKE_FLOW_SRC_IP) flow_hash ^= srchost_hash; if (flow_mode & CAKE_FLOW_DST_IP) flow_hash ^= dsthost_hash; } reduced_hash = flow_hash % CAKE_QUEUES; /* set-associative hashing */ /* fast path if no hash collision (direct lookup succeeds) */ if (likely(q->tags[reduced_hash] == flow_hash && q->flows[reduced_hash].set)) { q->way_directs++; } else { u32 inner_hash = reduced_hash % CAKE_SET_WAYS; u32 outer_hash = reduced_hash - inner_hash; bool allocate_src = false; bool allocate_dst = false; u32 i, k; /* check if any active queue in the set is reserved for * this flow. */ for (i = 0, k = inner_hash; i < CAKE_SET_WAYS; i++, k = (k + 1) % CAKE_SET_WAYS) { if (q->tags[outer_hash + k] == flow_hash) { if (i) q->way_hits++; if (!q->flows[outer_hash + k].set) { /* need to increment host refcnts */ allocate_src = cake_dsrc(flow_mode); allocate_dst = cake_ddst(flow_mode); } goto found; } } /* no queue is reserved for this flow, look for an * empty one. */ for (i = 0; i < CAKE_SET_WAYS; i++, k = (k + 1) % CAKE_SET_WAYS) { if (!q->flows[outer_hash + k].set) { q->way_misses++; allocate_src = cake_dsrc(flow_mode); allocate_dst = cake_ddst(flow_mode); goto found; } } /* With no empty queues, default to the original * queue, accept the collision, update the host tags. */ q->way_collisions++; if (q->flows[outer_hash + k].set == CAKE_SET_BULK) { q->hosts[q->flows[reduced_hash].srchost].srchost_bulk_flow_count--; q->hosts[q->flows[reduced_hash].dsthost].dsthost_bulk_flow_count--; } allocate_src = cake_dsrc(flow_mode); allocate_dst = cake_ddst(flow_mode); found: /* reserve queue for future packets in same flow */ reduced_hash = outer_hash + k; q->tags[reduced_hash] = flow_hash; if (allocate_src) { srchost_idx = srchost_hash % CAKE_QUEUES; inner_hash = srchost_idx % CAKE_SET_WAYS; outer_hash = srchost_idx - inner_hash; for (i = 0, k = inner_hash; i < CAKE_SET_WAYS; i++, k = (k + 1) % CAKE_SET_WAYS) { if (q->hosts[outer_hash + k].srchost_tag == srchost_hash) goto found_src; } for (i = 0; i < CAKE_SET_WAYS; i++, k = (k + 1) % CAKE_SET_WAYS) { if (!q->hosts[outer_hash + k].srchost_bulk_flow_count) break; } q->hosts[outer_hash + k].srchost_tag = srchost_hash; found_src: srchost_idx = outer_hash + k; if (q->flows[reduced_hash].set == CAKE_SET_BULK) q->hosts[srchost_idx].srchost_bulk_flow_count++; q->flows[reduced_hash].srchost = srchost_idx; } if (allocate_dst) { dsthost_idx = dsthost_hash % CAKE_QUEUES; inner_hash = dsthost_idx % CAKE_SET_WAYS; outer_hash = dsthost_idx - inner_hash; for (i = 0, k = inner_hash; i < CAKE_SET_WAYS; i++, k = (k + 1) % CAKE_SET_WAYS) { if (q->hosts[outer_hash + k].dsthost_tag == dsthost_hash) goto found_dst; } for (i = 0; i < CAKE_SET_WAYS; i++, k = (k + 1) % CAKE_SET_WAYS) { if (!q->hosts[outer_hash + k].dsthost_bulk_flow_count) break; } q->hosts[outer_hash + k].dsthost_tag = dsthost_hash; found_dst: dsthost_idx = outer_hash + k; if (q->flows[reduced_hash].set == CAKE_SET_BULK) q->hosts[dsthost_idx].dsthost_bulk_flow_count++; q->flows[reduced_hash].dsthost = dsthost_idx; } } return reduced_hash; } /* helper functions : might be changed when/if skb use a standard list_head */ /* remove one skb from head of slot queue */ static struct sk_buff *dequeue_head(struct cake_flow *flow) { struct sk_buff *skb = flow->head; if (skb) { flow->head = skb->next; skb_mark_not_on_list(skb); } return skb; } /* add skb to flow queue (tail add) */ static void flow_queue_add(struct cake_flow *flow, struct sk_buff *skb) { if (!flow->head) flow->head = skb; else flow->tail->next = skb; flow->tail = skb; skb->next = NULL; } static struct iphdr *cake_get_iphdr(const struct sk_buff *skb, struct ipv6hdr *buf) { unsigned int offset = skb_network_offset(skb); struct iphdr *iph; iph = skb_header_pointer(skb, offset, sizeof(struct iphdr), buf); if (!iph) return NULL; if (iph->version == 4 && iph->protocol == IPPROTO_IPV6) return skb_header_pointer(skb, offset + iph->ihl * 4, sizeof(struct ipv6hdr), buf); else if (iph->version == 4) return iph; else if (iph->version == 6) return skb_header_pointer(skb, offset, sizeof(struct ipv6hdr), buf); return NULL; } static struct tcphdr *cake_get_tcphdr(const struct sk_buff *skb, void *buf, unsigned int bufsize) { unsigned int offset = skb_network_offset(skb); const struct ipv6hdr *ipv6h; const struct tcphdr *tcph; const struct iphdr *iph; struct ipv6hdr _ipv6h; struct tcphdr _tcph; ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); if (!ipv6h) return NULL; if (ipv6h->version == 4) { iph = (struct iphdr *)ipv6h; offset += iph->ihl * 4; /* special-case 6in4 tunnelling, as that is a common way to get * v6 connectivity in the home */ if (iph->protocol == IPPROTO_IPV6) { ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP) return NULL; offset += sizeof(struct ipv6hdr); } else if (iph->protocol != IPPROTO_TCP) { return NULL; } } else if (ipv6h->version == 6) { if (ipv6h->nexthdr != IPPROTO_TCP) return NULL; offset += sizeof(struct ipv6hdr); } else { return NULL; } tcph = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); if (!tcph || tcph->doff < 5) return NULL; return skb_header_pointer(skb, offset, min(__tcp_hdrlen(tcph), bufsize), buf); } static const void *cake_get_tcpopt(const struct tcphdr *tcph, int code, int *oplen) { /* inspired by tcp_parse_options in tcp_input.c */ int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr); const u8 *ptr = (const u8 *)(tcph + 1); while (length > 0) { int opcode = *ptr++; int opsize; if (opcode == TCPOPT_EOL) break; if (opcode == TCPOPT_NOP) { length--; continue; } if (length < 2) break; opsize = *ptr++; if (opsize < 2 || opsize > length) break; if (opcode == code) { *oplen = opsize; return ptr; } ptr += opsize - 2; length -= opsize; } return NULL; } /* Compare two SACK sequences. A sequence is considered greater if it SACKs more * bytes than the other. In the case where both sequences ACKs bytes that the * other doesn't, A is considered greater. DSACKs in A also makes A be * considered greater. * * @return -1, 0 or 1 as normal compare functions */ static int cake_tcph_sack_compare(const struct tcphdr *tcph_a, const struct tcphdr *tcph_b) { const struct tcp_sack_block_wire *sack_a, *sack_b; u32 ack_seq_a = ntohl(tcph_a->ack_seq); u32 bytes_a = 0, bytes_b = 0; int oplen_a, oplen_b; bool first = true; sack_a = cake_get_tcpopt(tcph_a, TCPOPT_SACK, &oplen_a); sack_b = cake_get_tcpopt(tcph_b, TCPOPT_SACK, &oplen_b); /* pointers point to option contents */ oplen_a -= TCPOLEN_SACK_BASE; oplen_b -= TCPOLEN_SACK_BASE; if (sack_a && oplen_a >= sizeof(*sack_a) && (!sack_b || oplen_b < sizeof(*sack_b))) return -1; else if (sack_b && oplen_b >= sizeof(*sack_b) && (!sack_a || oplen_a < sizeof(*sack_a))) return 1; else if ((!sack_a || oplen_a < sizeof(*sack_a)) && (!sack_b || oplen_b < sizeof(*sack_b))) return 0; while (oplen_a >= sizeof(*sack_a)) { const struct tcp_sack_block_wire *sack_tmp = sack_b; u32 start_a = get_unaligned_be32(&sack_a->start_seq); u32 end_a = get_unaligned_be32(&sack_a->end_seq); int oplen_tmp = oplen_b; bool found = false; /* DSACK; always considered greater to prevent dropping */ if (before(start_a, ack_seq_a)) return -1; bytes_a += end_a - start_a; while (oplen_tmp >= sizeof(*sack_tmp)) { u32 start_b = get_unaligned_be32(&sack_tmp->start_seq); u32 end_b = get_unaligned_be32(&sack_tmp->end_seq); /* first time through we count the total size */ if (first) bytes_b += end_b - start_b; if (!after(start_b, start_a) && !before(end_b, end_a)) { found = true; if (!first) break; } oplen_tmp -= sizeof(*sack_tmp); sack_tmp++; } if (!found) return -1; oplen_a -= sizeof(*sack_a); sack_a++; first = false; } /* If we made it this far, all ranges SACKed by A are covered by B, so * either the SACKs are equal, or B SACKs more bytes. */ return bytes_b > bytes_a ? 1 : 0; } static void cake_tcph_get_tstamp(const struct tcphdr *tcph, u32 *tsval, u32 *tsecr) { const u8 *ptr; int opsize; ptr = cake_get_tcpopt(tcph, TCPOPT_TIMESTAMP, &opsize); if (ptr && opsize == TCPOLEN_TIMESTAMP) { *tsval = get_unaligned_be32(ptr); *tsecr = get_unaligned_be32(ptr + 4); } } static bool cake_tcph_may_drop(const struct tcphdr *tcph, u32 tstamp_new, u32 tsecr_new) { /* inspired by tcp_parse_options in tcp_input.c */ int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr); const u8 *ptr = (const u8 *)(tcph + 1); u32 tstamp, tsecr; /* 3 reserved flags must be unset to avoid future breakage * ACK must be set * ECE/CWR are handled separately * All other flags URG/PSH/RST/SYN/FIN must be unset * 0x0FFF0000 = all TCP flags (confirm ACK=1, others zero) * 0x00C00000 = CWR/ECE (handled separately) * 0x0F3F0000 = 0x0FFF0000 & ~0x00C00000 */ if (((tcp_flag_word(tcph) & cpu_to_be32(0x0F3F0000)) != TCP_FLAG_ACK)) return false; while (length > 0) { int opcode = *ptr++; int opsize; if (opcode == TCPOPT_EOL) break; if (opcode == TCPOPT_NOP) { length--; continue; } if (length < 2) break; opsize = *ptr++; if (opsize < 2 || opsize > length) break; switch (opcode) { case TCPOPT_MD5SIG: /* doesn't influence state */ break; case TCPOPT_SACK: /* stricter checking performed later */ if (opsize % 8 != 2) return false; break; case TCPOPT_TIMESTAMP: /* only drop timestamps lower than new */ if (opsize != TCPOLEN_TIMESTAMP) return false; tstamp = get_unaligned_be32(ptr); tsecr = get_unaligned_be32(ptr + 4); if (after(tstamp, tstamp_new) || after(tsecr, tsecr_new)) return false; break; case TCPOPT_MSS: /* these should only be set on SYN */ case TCPOPT_WINDOW: case TCPOPT_SACK_PERM: case TCPOPT_FASTOPEN: case TCPOPT_EXP: default: /* don't drop if any unknown options are present */ return false; } ptr += opsize - 2; length -= opsize; } return true; } static struct sk_buff *cake_ack_filter(struct cake_sched_data *q, struct cake_flow *flow) { bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE; struct sk_buff *elig_ack = NULL, *elig_ack_prev = NULL; struct sk_buff *skb_check, *skb_prev = NULL; const struct ipv6hdr *ipv6h, *ipv6h_check; unsigned char _tcph[64], _tcph_check[64]; const struct tcphdr *tcph, *tcph_check; const struct iphdr *iph, *iph_check; struct ipv6hdr _iph, _iph_check; const struct sk_buff *skb; int seglen, num_found = 0; u32 tstamp = 0, tsecr = 0; __be32 elig_flags = 0; int sack_comp; /* no other possible ACKs to filter */ if (flow->head == flow->tail) return NULL; skb = flow->tail; tcph = cake_get_tcphdr(skb, _tcph, sizeof(_tcph)); iph = cake_get_iphdr(skb, &_iph); if (!tcph) return NULL; cake_tcph_get_tstamp(tcph, &tstamp, &tsecr); /* the 'triggering' packet need only have the ACK flag set. * also check that SYN is not set, as there won't be any previous ACKs. */ if ((tcp_flag_word(tcph) & (TCP_FLAG_ACK | TCP_FLAG_SYN)) != TCP_FLAG_ACK) return NULL; /* the 'triggering' ACK is at the tail of the queue, we have already * returned if it is the only packet in the flow. loop through the rest * of the queue looking for pure ACKs with the same 5-tuple as the * triggering one. */ for (skb_check = flow->head; skb_check && skb_check != skb; skb_prev = skb_check, skb_check = skb_check->next) { iph_check = cake_get_iphdr(skb_check, &_iph_check); tcph_check = cake_get_tcphdr(skb_check, &_tcph_check, sizeof(_tcph_check)); /* only TCP packets with matching 5-tuple are eligible, and only * drop safe headers */ if (!tcph_check || iph->version != iph_check->version || tcph_check->source != tcph->source || tcph_check->dest != tcph->dest) continue; if (iph_check->version == 4) { if (iph_check->saddr != iph->saddr || iph_check->daddr != iph->daddr) continue; seglen = iph_totlen(skb, iph_check) - (4 * iph_check->ihl); } else if (iph_check->version == 6) { ipv6h = (struct ipv6hdr *)iph; ipv6h_check = (struct ipv6hdr *)iph_check; if (ipv6_addr_cmp(&ipv6h_check->saddr, &ipv6h->saddr) || ipv6_addr_cmp(&ipv6h_check->daddr, &ipv6h->daddr)) continue; seglen = ntohs(ipv6h_check->payload_len); } else { WARN_ON(1); /* shouldn't happen */ continue; } /* If the ECE/CWR flags changed from the previous eligible * packet in the same flow, we should no longer be dropping that * previous packet as this would lose information. */ if (elig_ack && (tcp_flag_word(tcph_check) & (TCP_FLAG_ECE | TCP_FLAG_CWR)) != elig_flags) { elig_ack = NULL; elig_ack_prev = NULL; num_found--; } /* Check TCP options and flags, don't drop ACKs with segment * data, and don't drop ACKs with a higher cumulative ACK * counter than the triggering packet. Check ACK seqno here to * avoid parsing SACK options of packets we are going to exclude * anyway. */ if (!cake_tcph_may_drop(tcph_check, tstamp, tsecr) || (seglen - __tcp_hdrlen(tcph_check)) != 0 || after(ntohl(tcph_check->ack_seq), ntohl(tcph->ack_seq))) continue; /* Check SACK options. The triggering packet must SACK more data * than the ACK under consideration, or SACK the same range but * have a larger cumulative ACK counter. The latter is a * pathological case, but is contained in the following check * anyway, just to be safe. */ sack_comp = cake_tcph_sack_compare(tcph_check, tcph); if (sack_comp < 0 || (ntohl(tcph_check->ack_seq) == ntohl(tcph->ack_seq) && sack_comp == 0)) continue; /* At this point we have found an eligible pure ACK to drop; if * we are in aggressive mode, we are done. Otherwise, keep * searching unless this is the second eligible ACK we * found. * * Since we want to drop ACK closest to the head of the queue, * save the first eligible ACK we find, even if we need to loop * again. */ if (!elig_ack) { elig_ack = skb_check; elig_ack_prev = skb_prev; elig_flags = (tcp_flag_word(tcph_check) & (TCP_FLAG_ECE | TCP_FLAG_CWR)); } if (num_found++ > 0) goto found; } /* We made it through the queue without finding two eligible ACKs . If * we found a single eligible ACK we can drop it in aggressive mode if * we can guarantee that this does not interfere with ECN flag * information. We ensure this by dropping it only if the enqueued * packet is consecutive with the eligible ACK, and their flags match. */ if (elig_ack && aggressive && elig_ack->next == skb && (elig_flags == (tcp_flag_word(tcph) & (TCP_FLAG_ECE | TCP_FLAG_CWR)))) goto found; return NULL; found: if (elig_ack_prev) elig_ack_prev->next = elig_ack->next; else flow->head = elig_ack->next; skb_mark_not_on_list(elig_ack); return elig_ack; } static u64 cake_ewma(u64 avg, u64 sample, u32 shift) { avg -= avg >> shift; avg += sample >> shift; return avg; } static u32 cake_calc_overhead(struct cake_sched_data *q, u32 len, u32 off) { if (q->rate_flags & CAKE_FLAG_OVERHEAD) len -= off; if (q->max_netlen < len) q->max_netlen = len; if (q->min_netlen > len) q->min_netlen = len; len += q->rate_overhead; if (len < q->rate_mpu) len = q->rate_mpu; if (q->atm_mode == CAKE_ATM_ATM) { len += 47; len /= 48; len *= 53; } else if (q->atm_mode == CAKE_ATM_PTM) { /* Add one byte per 64 bytes or part thereof. * This is conservative and easier to calculate than the * precise value. */ len += (len + 63) / 64; } if (q->max_adjlen < len) q->max_adjlen = len; if (q->min_adjlen > len) q->min_adjlen = len; return len; } static u32 cake_overhead(struct cake_sched_data *q, const struct sk_buff *skb) { const struct skb_shared_info *shinfo = skb_shinfo(skb); unsigned int hdr_len, last_len = 0; u32 off = skb_network_offset(skb); u32 len = qdisc_pkt_len(skb); u16 segs = 1; q->avg_netoff = cake_ewma(q->avg_netoff, off << 16, 8); if (!shinfo->gso_size) return cake_calc_overhead(q, len, off); /* borrowed from qdisc_pkt_len_init() */ hdr_len = skb_transport_offset(skb); /* + transport layer */ if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) { const struct tcphdr *th; struct tcphdr _tcphdr; th = skb_header_pointer(skb, hdr_len, sizeof(_tcphdr), &_tcphdr); if (likely(th)) hdr_len += __tcp_hdrlen(th); } else { struct udphdr _udphdr; if (skb_header_pointer(skb, hdr_len, sizeof(_udphdr), &_udphdr)) hdr_len += sizeof(struct udphdr); } if (unlikely(shinfo->gso_type & SKB_GSO_DODGY)) segs = DIV_ROUND_UP(skb->len - hdr_len, shinfo->gso_size); else segs = shinfo->gso_segs; len = shinfo->gso_size + hdr_len; last_len = skb->len - shinfo->gso_size * (segs - 1); return (cake_calc_overhead(q, len, off) * (segs - 1) + cake_calc_overhead(q, last_len, off)); } static void cake_heap_swap(struct cake_sched_data *q, u16 i, u16 j) { struct cake_heap_entry ii = q->overflow_heap[i]; struct cake_heap_entry jj = q->overflow_heap[j]; q->overflow_heap[i] = jj; q->overflow_heap[j] = ii; q->tins[ii.t].overflow_idx[ii.b] = j; q->tins[jj.t].overflow_idx[jj.b] = i; } static u32 cake_heap_get_backlog(const struct cake_sched_data *q, u16 i) { struct cake_heap_entry ii = q->overflow_heap[i]; return q->tins[ii.t].backlogs[ii.b]; } static void cake_heapify(struct cake_sched_data *q, u16 i) { static const u32 a = CAKE_MAX_TINS * CAKE_QUEUES; u32 mb = cake_heap_get_backlog(q, i); u32 m = i; while (m < a) { u32 l = m + m + 1; u32 r = l + 1; if (l < a) { u32 lb = cake_heap_get_backlog(q, l); if (lb > mb) { m = l; mb = lb; } } if (r < a) { u32 rb = cake_heap_get_backlog(q, r); if (rb > mb) { m = r; mb = rb; } } if (m != i) { cake_heap_swap(q, i, m); i = m; } else { break; } } } static void cake_heapify_up(struct cake_sched_data *q, u16 i) { while (i > 0 && i < CAKE_MAX_TINS * CAKE_QUEUES) { u16 p = (i - 1) >> 1; u32 ib = cake_heap_get_backlog(q, i); u32 pb = cake_heap_get_backlog(q, p); if (ib > pb) { cake_heap_swap(q, i, p); i = p; } else { break; } } } static int cake_advance_shaper(struct cake_sched_data *q, struct cake_tin_data *b, struct sk_buff *skb, ktime_t now, bool drop) { u32 len = get_cobalt_cb(skb)->adjusted_len; /* charge packet bandwidth to this tin * and to the global shaper. */ if (q->rate_ns) { u64 tin_dur = (len * b->tin_rate_ns) >> b->tin_rate_shft; u64 global_dur = (len * q->rate_ns) >> q->rate_shft; u64 failsafe_dur = global_dur + (global_dur >> 1); if (ktime_before(b->time_next_packet, now)) b->time_next_packet = ktime_add_ns(b->time_next_packet, tin_dur); else if (ktime_before(b->time_next_packet, ktime_add_ns(now, tin_dur))) b->time_next_packet = ktime_add_ns(now, tin_dur); q->time_next_packet = ktime_add_ns(q->time_next_packet, global_dur); if (!drop) q->failsafe_next_packet = \ ktime_add_ns(q->failsafe_next_packet, failsafe_dur); } return len; } static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free) { struct cake_sched_data *q = qdisc_priv(sch); ktime_t now = ktime_get(); u32 idx = 0, tin = 0, len; struct cake_heap_entry qq; struct cake_tin_data *b; struct cake_flow *flow; struct sk_buff *skb; if (!q->overflow_timeout) { int i; /* Build fresh max-heap */ for (i = CAKE_MAX_TINS * CAKE_QUEUES / 2; i >= 0; i--) cake_heapify(q, i); } q->overflow_timeout = 65535; /* select longest queue for pruning */ qq = q->overflow_heap[0]; tin = qq.t; idx = qq.b; b = &q->tins[tin]; flow = &b->flows[idx]; skb = dequeue_head(flow); if (unlikely(!skb)) { /* heap has gone wrong, rebuild it next time */ q->overflow_timeout = 0; return idx + (tin << 16); } if (cobalt_queue_full(&flow->cvars, &b->cparams, now)) b->unresponsive_flow_count++; len = qdisc_pkt_len(skb); q->buffer_used -= skb->truesize; b->backlogs[idx] -= len; b->tin_backlog -= len; sch->qstats.backlog -= len; qdisc_tree_reduce_backlog(sch, 1, len); flow->dropped++; b->tin_dropped++; sch->qstats.drops++; if (q->rate_flags & CAKE_FLAG_INGRESS) cake_advance_shaper(q, b, skb, now, true); __qdisc_drop(skb, to_free); sch->q.qlen--; cake_heapify(q, 0); return idx + (tin << 16); } static u8 cake_handle_diffserv(struct sk_buff *skb, bool wash) { const int offset = skb_network_offset(skb); u16 *buf, buf_; u8 dscp; switch (skb_protocol(skb, true)) { case htons(ETH_P_IP): buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_); if (unlikely(!buf)) return 0; /* ToS is in the second byte of iphdr */ dscp = ipv4_get_dsfield((struct iphdr *)buf) >> 2; if (wash && dscp) { const int wlen = offset + sizeof(struct iphdr); if (!pskb_may_pull(skb, wlen) || skb_try_make_writable(skb, wlen)) return 0; ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0); } return dscp; case htons(ETH_P_IPV6): buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_); if (unlikely(!buf)) return 0; /* Traffic class is in the first and second bytes of ipv6hdr */ dscp = ipv6_get_dsfield((struct ipv6hdr *)buf) >> 2; if (wash && dscp) { const int wlen = offset + sizeof(struct ipv6hdr); if (!pskb_may_pull(skb, wlen) || skb_try_make_writable(skb, wlen)) return 0; ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0); } return dscp; case htons(ETH_P_ARP): return 0x38; /* CS7 - Net Control */ default: /* If there is no Diffserv field, treat as best-effort */ return 0; } } static struct cake_tin_data *cake_select_tin(struct Qdisc *sch, struct sk_buff *skb) { struct cake_sched_data *q = qdisc_priv(sch); u32 tin, mark; bool wash; u8 dscp; /* Tin selection: Default to diffserv-based selection, allow overriding * using firewall marks or skb->priority. Call DSCP parsing early if * wash is enabled, otherwise defer to below to skip unneeded parsing. */ mark = (skb->mark & q->fwmark_mask) >> q->fwmark_shft; wash = !!(q->rate_flags & CAKE_FLAG_WASH); if (wash) dscp = cake_handle_diffserv(skb, wash); if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT) tin = 0; else if (mark && mark <= q->tin_cnt) tin = q->tin_order[mark - 1]; else if (TC_H_MAJ(skb->priority) == sch->handle && TC_H_MIN(skb->priority) > 0 && TC_H_MIN(skb->priority) <= q->tin_cnt) tin = q->tin_order[TC_H_MIN(skb->priority) - 1]; else { if (!wash) dscp = cake_handle_diffserv(skb, wash); tin = q->tin_index[dscp]; if (unlikely(tin >= q->tin_cnt)) tin = 0; } return &q->tins[tin]; } static u32 cake_classify(struct Qdisc *sch, struct cake_tin_data **t, struct sk_buff *skb, int flow_mode, int *qerr) { struct cake_sched_data *q = qdisc_priv(sch); struct tcf_proto *filter; struct tcf_result res; u16 flow = 0, host = 0; int result; filter = rcu_dereference_bh(q->filter_list); if (!filter) goto hash; *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; result = tcf_classify(skb, NULL, filter, &res, false); if (result >= 0) { #ifdef CONFIG_NET_CLS_ACT switch (result) { case TC_ACT_STOLEN: case TC_ACT_QUEUED: case TC_ACT_TRAP: *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; fallthrough; case TC_ACT_SHOT: return 0; } #endif if (TC_H_MIN(res.classid) <= CAKE_QUEUES) flow = TC_H_MIN(res.classid); if (TC_H_MAJ(res.classid) <= (CAKE_QUEUES << 16)) host = TC_H_MAJ(res.classid) >> 16; } hash: *t = cake_select_tin(sch, skb); return cake_hash(*t, skb, flow_mode, flow, host) + 1; } static void cake_reconfigure(struct Qdisc *sch); static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { struct cake_sched_data *q = qdisc_priv(sch); int len = qdisc_pkt_len(skb); int ret; struct sk_buff *ack = NULL; ktime_t now = ktime_get(); struct cake_tin_data *b; struct cake_flow *flow; u32 idx; /* choose flow to insert into */ idx = cake_classify(sch, &b, skb, q->flow_mode, &ret); if (idx == 0) { if (ret & __NET_XMIT_BYPASS) qdisc_qstats_drop(sch); __qdisc_drop(skb, to_free); return ret; } idx--; flow = &b->flows[idx]; /* ensure shaper state isn't stale */ if (!b->tin_backlog) { if (ktime_before(b->time_next_packet, now)) b->time_next_packet = now; if (!sch->q.qlen) { if (ktime_before(q->time_next_packet, now)) { q->failsafe_next_packet = now; q->time_next_packet = now; } else if (ktime_after(q->time_next_packet, now) && ktime_after(q->failsafe_next_packet, now)) { u64 next = \ min(ktime_to_ns(q->time_next_packet), ktime_to_ns( q->failsafe_next_packet)); sch->qstats.overlimits++; qdisc_watchdog_schedule_ns(&q->watchdog, next); } } } if (unlikely(len > b->max_skblen)) b->max_skblen = len; if (skb_is_gso(skb) && q->rate_flags & CAKE_FLAG_SPLIT_GSO) { struct sk_buff *segs, *nskb; netdev_features_t features = netif_skb_features(skb); unsigned int slen = 0, numsegs = 0; segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); if (IS_ERR_OR_NULL(segs)) return qdisc_drop(skb, sch, to_free); skb_list_walk_safe(segs, segs, nskb) { skb_mark_not_on_list(segs); qdisc_skb_cb(segs)->pkt_len = segs->len; cobalt_set_enqueue_time(segs, now); get_cobalt_cb(segs)->adjusted_len = cake_overhead(q, segs); flow_queue_add(flow, segs); sch->q.qlen++; numsegs++; slen += segs->len; q->buffer_used += segs->truesize; b->packets++; } /* stats */ b->bytes += slen; b->backlogs[idx] += slen; b->tin_backlog += slen; sch->qstats.backlog += slen; q->avg_window_bytes += slen; qdisc_tree_reduce_backlog(sch, 1-numsegs, len-slen); consume_skb(skb); } else { /* not splitting */ cobalt_set_enqueue_time(skb, now); get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb); flow_queue_add(flow, skb); if (q->ack_filter) ack = cake_ack_filter(q, flow); if (ack) { b->ack_drops++; sch->qstats.drops++; b->bytes += qdisc_pkt_len(ack); len -= qdisc_pkt_len(ack); q->buffer_used += skb->truesize - ack->truesize; if (q->rate_flags & CAKE_FLAG_INGRESS) cake_advance_shaper(q, b, ack, now, true); qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack)); consume_skb(ack); } else { sch->q.qlen++; q->buffer_used += skb->truesize; } /* stats */ b->packets++; b->bytes += len; b->backlogs[idx] += len; b->tin_backlog += len; sch->qstats.backlog += len; q->avg_window_bytes += len; } if (q->overflow_timeout) cake_heapify_up(q, b->overflow_idx[idx]); /* incoming bandwidth capacity estimate */ if (q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS) { u64 packet_interval = \ ktime_to_ns(ktime_sub(now, q->last_packet_time)); if (packet_interval > NSEC_PER_SEC) packet_interval = NSEC_PER_SEC; /* filter out short-term bursts, eg. wifi aggregation */ q->avg_packet_interval = \ cake_ewma(q->avg_packet_interval, packet_interval, (packet_interval > q->avg_packet_interval ? 2 : 8)); q->last_packet_time = now; if (packet_interval > q->avg_packet_interval) { u64 window_interval = \ ktime_to_ns(ktime_sub(now, q->avg_window_begin)); u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC; b = div64_u64(b, window_interval); q->avg_peak_bandwidth = cake_ewma(q->avg_peak_bandwidth, b, b > q->avg_peak_bandwidth ? 2 : 8); q->avg_window_bytes = 0; q->avg_window_begin = now; if (ktime_after(now, ktime_add_ms(q->last_reconfig_time, 250))) { q->rate_bps = (q->avg_peak_bandwidth * 15) >> 4; cake_reconfigure(sch); } } } else { q->avg_window_bytes = 0; q->last_packet_time = now; } /* flowchain */ if (!flow->set || flow->set == CAKE_SET_DECAYING) { struct cake_host *srchost = &b->hosts[flow->srchost]; struct cake_host *dsthost = &b->hosts[flow->dsthost]; u16 host_load = 1; if (!flow->set) { list_add_tail(&flow->flowchain, &b->new_flows); } else { b->decaying_flow_count--; list_move_tail(&flow->flowchain, &b->new_flows); } flow->set = CAKE_SET_SPARSE; b->sparse_flow_count++; if (cake_dsrc(q->flow_mode)) host_load = max(host_load, srchost->srchost_bulk_flow_count); if (cake_ddst(q->flow_mode)) host_load = max(host_load, dsthost->dsthost_bulk_flow_count); flow->deficit = (b->flow_quantum * quantum_div[host_load]) >> 16; } else if (flow->set == CAKE_SET_SPARSE_WAIT) { struct cake_host *srchost = &b->hosts[flow->srchost]; struct cake_host *dsthost = &b->hosts[flow->dsthost]; /* this flow was empty, accounted as a sparse flow, but actually * in the bulk rotation. */ flow->set = CAKE_SET_BULK; b->sparse_flow_count--; b->bulk_flow_count++; if (cake_dsrc(q->flow_mode)) srchost->srchost_bulk_flow_count++; if (cake_ddst(q->flow_mode)) dsthost->dsthost_bulk_flow_count++; } if (q->buffer_used > q->buffer_max_used) q->buffer_max_used = q->buffer_used; if (q->buffer_used > q->buffer_limit) { u32 dropped = 0; while (q->buffer_used > q->buffer_limit) { dropped++; cake_drop(sch, to_free); } b->drop_overlimit += dropped; } return NET_XMIT_SUCCESS; } static struct sk_buff *cake_dequeue_one(struct Qdisc *sch) { struct cake_sched_data *q = qdisc_priv(sch); struct cake_tin_data *b = &q->tins[q->cur_tin]; struct cake_flow *flow = &b->flows[q->cur_flow]; struct sk_buff *skb = NULL; u32 len; if (flow->head) { skb = dequeue_head(flow); len = qdisc_pkt_len(skb); b->backlogs[q->cur_flow] -= len; b->tin_backlog -= len; sch->qstats.backlog -= len; q->buffer_used -= skb->truesize; sch->q.qlen--; if (q->overflow_timeout) cake_heapify(q, b->overflow_idx[q->cur_flow]); } return skb; } /* Discard leftover packets from a tin no longer in use. */ static void cake_clear_tin(struct Qdisc *sch, u16 tin) { struct cake_sched_data *q = qdisc_priv(sch); struct sk_buff *skb; q->cur_tin = tin; for (q->cur_flow = 0; q->cur_flow < CAKE_QUEUES; q->cur_flow++) while (!!(skb = cake_dequeue_one(sch))) kfree_skb(skb); } static struct sk_buff *cake_dequeue(struct Qdisc *sch) { struct cake_sched_data *q = qdisc_priv(sch); struct cake_tin_data *b = &q->tins[q->cur_tin]; struct cake_host *srchost, *dsthost; ktime_t now = ktime_get(); struct cake_flow *flow; struct list_head *head; bool first_flow = true; struct sk_buff *skb; u16 host_load; u64 delay; u32 len; begin: if (!sch->q.qlen) return NULL; /* global hard shaper */ if (ktime_after(q->time_next_packet, now) && ktime_after(q->failsafe_next_packet, now)) { u64 next = min(ktime_to_ns(q->time_next_packet), ktime_to_ns(q->failsafe_next_packet)); sch->qstats.overlimits++; qdisc_watchdog_schedule_ns(&q->watchdog, next); return NULL; } /* Choose a class to work on. */ if (!q->rate_ns) { /* In unlimited mode, can't rely on shaper timings, just balance * with DRR */ bool wrapped = false, empty = true; while (b->tin_deficit < 0 || !(b->sparse_flow_count + b->bulk_flow_count)) { if (b->tin_deficit <= 0) b->tin_deficit += b->tin_quantum; if (b->sparse_flow_count + b->bulk_flow_count) empty = false; q->cur_tin++; b++; if (q->cur_tin >= q->tin_cnt) { q->cur_tin = 0; b = q->tins; if (wrapped) { /* It's possible for q->qlen to be * nonzero when we actually have no * packets anywhere. */ if (empty) return NULL; } else { wrapped = true; } } } } else { /* In shaped mode, choose: * - Highest-priority tin with queue and meeting schedule, or * - The earliest-scheduled tin with queue. */ ktime_t best_time = KTIME_MAX; int tin, best_tin = 0; for (tin = 0; tin < q->tin_cnt; tin++) { b = q->tins + tin; if ((b->sparse_flow_count + b->bulk_flow_count) > 0) { ktime_t time_to_pkt = \ ktime_sub(b->time_next_packet, now); if (ktime_to_ns(time_to_pkt) <= 0 || ktime_compare(time_to_pkt, best_time) <= 0) { best_time = time_to_pkt; best_tin = tin; } } } q->cur_tin = best_tin; b = q->tins + best_tin; /* No point in going further if no packets to deliver. */ if (unlikely(!(b->sparse_flow_count + b->bulk_flow_count))) return NULL; } retry: /* service this class */ head = &b->decaying_flows; if (!first_flow || list_empty(head)) { head = &b->new_flows; if (list_empty(head)) { head = &b->old_flows; if (unlikely(list_empty(head))) { head = &b->decaying_flows; if (unlikely(list_empty(head))) goto begin; } } } flow = list_first_entry(head, struct cake_flow, flowchain); q->cur_flow = flow - b->flows; first_flow = false; /* triple isolation (modified DRR++) */ srchost = &b->hosts[flow->srchost]; dsthost = &b->hosts[flow->dsthost]; host_load = 1; /* flow isolation (DRR++) */ if (flow->deficit <= 0) { /* Keep all flows with deficits out of the sparse and decaying * rotations. No non-empty flow can go into the decaying * rotation, so they can't get deficits */ if (flow->set == CAKE_SET_SPARSE) { if (flow->head) { b->sparse_flow_count--; b->bulk_flow_count++; if (cake_dsrc(q->flow_mode)) srchost->srchost_bulk_flow_count++; if (cake_ddst(q->flow_mode)) dsthost->dsthost_bulk_flow_count++; flow->set = CAKE_SET_BULK; } else { /* we've moved it to the bulk rotation for * correct deficit accounting but we still want * to count it as a sparse flow, not a bulk one. */ flow->set = CAKE_SET_SPARSE_WAIT; } } if (cake_dsrc(q->flow_mode)) host_load = max(host_load, srchost->srchost_bulk_flow_count); if (cake_ddst(q->flow_mode)) host_load = max(host_load, dsthost->dsthost_bulk_flow_count); WARN_ON(host_load > CAKE_QUEUES); /* The get_random_u16() is a way to apply dithering to avoid * accumulating roundoff errors */ flow->deficit += (b->flow_quantum * quantum_div[host_load] + get_random_u16()) >> 16; list_move_tail(&flow->flowchain, &b->old_flows); goto retry; } /* Retrieve a packet via the AQM */ while (1) { skb = cake_dequeue_one(sch); if (!skb) { /* this queue was actually empty */ if (cobalt_queue_empty(&flow->cvars, &b->cparams, now)) b->unresponsive_flow_count--; if (flow->cvars.p_drop || flow->cvars.count || ktime_before(now, flow->cvars.drop_next)) { /* keep in the flowchain until the state has * decayed to rest */ list_move_tail(&flow->flowchain, &b->decaying_flows); if (flow->set == CAKE_SET_BULK) { b->bulk_flow_count--; if (cake_dsrc(q->flow_mode)) srchost->srchost_bulk_flow_count--; if (cake_ddst(q->flow_mode)) dsthost->dsthost_bulk_flow_count--; b->decaying_flow_count++; } else if (flow->set == CAKE_SET_SPARSE || flow->set == CAKE_SET_SPARSE_WAIT) { b->sparse_flow_count--; b->decaying_flow_count++; } flow->set = CAKE_SET_DECAYING; } else { /* remove empty queue from the flowchain */ list_del_init(&flow->flowchain); if (flow->set == CAKE_SET_SPARSE || flow->set == CAKE_SET_SPARSE_WAIT) b->sparse_flow_count--; else if (flow->set == CAKE_SET_BULK) { b->bulk_flow_count--; if (cake_dsrc(q->flow_mode)) srchost->srchost_bulk_flow_count--; if (cake_ddst(q->flow_mode)) dsthost->dsthost_bulk_flow_count--; } else b->decaying_flow_count--; flow->set = CAKE_SET_NONE; } goto begin; } /* Last packet in queue may be marked, shouldn't be dropped */ if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb, (b->bulk_flow_count * !!(q->rate_flags & CAKE_FLAG_INGRESS))) || !flow->head) break; /* drop this packet, get another one */ if (q->rate_flags & CAKE_FLAG_INGRESS) { len = cake_advance_shaper(q, b, skb, now, true); flow->deficit -= len; b->tin_deficit -= len; } flow->dropped++; b->tin_dropped++; qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb)); qdisc_qstats_drop(sch); kfree_skb(skb); if (q->rate_flags & CAKE_FLAG_INGRESS) goto retry; } b->tin_ecn_mark += !!flow->cvars.ecn_marked; qdisc_bstats_update(sch, skb); /* collect delay stats */ delay = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb))); b->avge_delay = cake_ewma(b->avge_delay, delay, 8); b->peak_delay = cake_ewma(b->peak_delay, delay, delay > b->peak_delay ? 2 : 8); b->base_delay = cake_ewma(b->base_delay, delay, delay < b->base_delay ? 2 : 8); len = cake_advance_shaper(q, b, skb, now, false); flow->deficit -= len; b->tin_deficit -= len; if (ktime_after(q->time_next_packet, now) && sch->q.qlen) { u64 next = min(ktime_to_ns(q->time_next_packet), ktime_to_ns(q->failsafe_next_packet)); qdisc_watchdog_schedule_ns(&q->watchdog, next); } else if (!sch->q.qlen) { int i; for (i = 0; i < q->tin_cnt; i++) { if (q->tins[i].decaying_flow_count) { ktime_t next = \ ktime_add_ns(now, q->tins[i].cparams.target); qdisc_watchdog_schedule_ns(&q->watchdog, ktime_to_ns(next)); break; } } } if (q->overflow_timeout) q->overflow_timeout--; return skb; } static void cake_reset(struct Qdisc *sch) { struct cake_sched_data *q = qdisc_priv(sch); u32 c; if (!q->tins) return; for (c = 0; c < CAKE_MAX_TINS; c++) cake_clear_tin(sch, c); } static const struct nla_policy cake_policy[TCA_CAKE_MAX + 1] = { [TCA_CAKE_BASE_RATE64] = { .type = NLA_U64 }, [TCA_CAKE_DIFFSERV_MODE] = { .type = NLA_U32 }, [TCA_CAKE_ATM] = { .type = NLA_U32 }, [TCA_CAKE_FLOW_MODE] = { .type = NLA_U32 }, [TCA_CAKE_OVERHEAD] = { .type = NLA_S32 }, [TCA_CAKE_RTT] = { .type = NLA_U32 }, [TCA_CAKE_TARGET] = { .type = NLA_U32 }, [TCA_CAKE_AUTORATE] = { .type = NLA_U32 }, [TCA_CAKE_MEMORY] = { .type = NLA_U32 }, [TCA_CAKE_NAT] = { .type = NLA_U32 }, [TCA_CAKE_RAW] = { .type = NLA_U32 }, [TCA_CAKE_WASH] = { .type = NLA_U32 }, [TCA_CAKE_MPU] = { .type = NLA_U32 }, [TCA_CAKE_INGRESS] = { .type = NLA_U32 }, [TCA_CAKE_ACK_FILTER] = { .type = NLA_U32 }, [TCA_CAKE_SPLIT_GSO] = { .type = NLA_U32 }, [TCA_CAKE_FWMARK] = { .type = NLA_U32 }, }; static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu, u64 target_ns, u64 rtt_est_ns) { /* convert byte-rate into time-per-byte * so it will always unwedge in reasonable time. */ static const u64 MIN_RATE = 64; u32 byte_target = mtu; u64 byte_target_ns; u8 rate_shft = 0; u64 rate_ns = 0; b->flow_quantum = 1514; if (rate) { b->flow_quantum = max(min(rate >> 12, 1514ULL), 300ULL); rate_shft = 34; rate_ns = ((u64)NSEC_PER_SEC) << rate_shft; rate_ns = div64_u64(rate_ns, max(MIN_RATE, rate)); while (!!(rate_ns >> 34)) { rate_ns >>= 1; rate_shft--; } } /* else unlimited, ie. zero delay */ b->tin_rate_bps = rate; b->tin_rate_ns = rate_ns; b->tin_rate_shft = rate_shft; byte_target_ns = (byte_target * rate_ns) >> rate_shft; b->cparams.target = max((byte_target_ns * 3) / 2, target_ns); b->cparams.interval = max(rtt_est_ns + b->cparams.target - target_ns, b->cparams.target * 2); b->cparams.mtu_time = byte_target_ns; b->cparams.p_inc = 1 << 24; /* 1/256 */ b->cparams.p_dec = 1 << 20; /* 1/4096 */ } static int cake_config_besteffort(struct Qdisc *sch) { struct cake_sched_data *q = qdisc_priv(sch); struct cake_tin_data *b = &q->tins[0]; u32 mtu = psched_mtu(qdisc_dev(sch)); u64 rate = q->rate_bps; q->tin_cnt = 1; q->tin_index = besteffort; q->tin_order = normal_order; cake_set_rate(b, rate, mtu, us_to_ns(q->target), us_to_ns(q->interval)); b->tin_quantum = 65535; return 0; } static int cake_config_precedence(struct Qdisc *sch) { /* convert high-level (user visible) parameters into internal format */ struct cake_sched_data *q = qdisc_priv(sch); u32 mtu = psched_mtu(qdisc_dev(sch)); u64 rate = q->rate_bps; u32 quantum = 256; u32 i; q->tin_cnt = 8; q->tin_index = precedence; q->tin_order = normal_order; for (i = 0; i < q->tin_cnt; i++) { struct cake_tin_data *b = &q->tins[i]; cake_set_rate(b, rate, mtu, us_to_ns(q->target), us_to_ns(q->interval)); b->tin_quantum = max_t(u16, 1U, quantum); /* calculate next class's parameters */ rate *= 7; rate >>= 3; quantum *= 7; quantum >>= 3; } return 0; } /* List of known Diffserv codepoints: * * Default Forwarding (DF/CS0) - Best Effort * Max Throughput (TOS2) * Min Delay (TOS4) * LLT "La" (TOS5) * Assured Forwarding 1 (AF1x) - x3 * Assured Forwarding 2 (AF2x) - x3 * Assured Forwarding 3 (AF3x) - x3 * Assured Forwarding 4 (AF4x) - x3 * Precedence Class 1 (CS1) * Precedence Class 2 (CS2) * Precedence Class 3 (CS3) * Precedence Class 4 (CS4) * Precedence Class 5 (CS5) * Precedence Class 6 (CS6) * Precedence Class 7 (CS7) * Voice Admit (VA) * Expedited Forwarding (EF) * Lower Effort (LE) * * Total 26 codepoints. */ /* List of traffic classes in RFC 4594, updated by RFC 8622: * (roughly descending order of contended priority) * (roughly ascending order of uncontended throughput) * * Network Control (CS6,CS7) - routing traffic * Telephony (EF,VA) - aka. VoIP streams * Signalling (CS5) - VoIP setup * Multimedia Conferencing (AF4x) - aka. video calls * Realtime Interactive (CS4) - eg. games * Multimedia Streaming (AF3x) - eg. YouTube, NetFlix, Twitch * Broadcast Video (CS3) * Low-Latency Data (AF2x,TOS4) - eg. database * Ops, Admin, Management (CS2) - eg. ssh * Standard Service (DF & unrecognised codepoints) * High-Throughput Data (AF1x,TOS2) - eg. web traffic * Low-Priority Data (LE,CS1) - eg. BitTorrent * * Total 12 traffic classes. */ static int cake_config_diffserv8(struct Qdisc *sch) { /* Pruned list of traffic classes for typical applications: * * Network Control (CS6, CS7) * Minimum Latency (EF, VA, CS5, CS4) * Interactive Shell (CS2) * Low Latency Transactions (AF2x, TOS4) * Video Streaming (AF4x, AF3x, CS3) * Bog Standard (DF etc.) * High Throughput (AF1x, TOS2, CS1) * Background Traffic (LE) * * Total 8 traffic classes. */ struct cake_sched_data *q = qdisc_priv(sch); u32 mtu = psched_mtu(qdisc_dev(sch)); u64 rate = q->rate_bps; u32 quantum = 256; u32 i; q->tin_cnt = 8; /* codepoint to class mapping */ q->tin_index = diffserv8; q->tin_order = normal_order; /* class characteristics */ for (i = 0; i < q->tin_cnt; i++) { struct cake_tin_data *b = &q->tins[i]; cake_set_rate(b, rate, mtu, us_to_ns(q->target), us_to_ns(q->interval)); b->tin_quantum = max_t(u16, 1U, quantum); /* calculate next class's parameters */ rate *= 7; rate >>= 3; quantum *= 7; quantum >>= 3; } return 0; } static int cake_config_diffserv4(struct Qdisc *sch) { /* Further pruned list of traffic classes for four-class system: * * Latency Sensitive (CS7, CS6, EF, VA, CS5, CS4) * Streaming Media (AF4x, AF3x, CS3, AF2x, TOS4, CS2) * Best Effort (DF, AF1x, TOS2, and those not specified) * Background Traffic (LE, CS1) * * Total 4 traffic classes. */ struct cake_sched_data *q = qdisc_priv(sch); u32 mtu = psched_mtu(qdisc_dev(sch)); u64 rate = q->rate_bps; u32 quantum = 1024; q->tin_cnt = 4; /* codepoint to class mapping */ q->tin_index = diffserv4; q->tin_order = bulk_order; /* class characteristics */ cake_set_rate(&q->tins[0], rate, mtu, us_to_ns(q->target), us_to_ns(q->interval)); cake_set_rate(&q->tins[1], rate >> 4, mtu, us_to_ns(q->target), us_to_ns(q->interval)); cake_set_rate(&q->tins[2], rate >> 1, mtu, us_to_ns(q->target), us_to_ns(q->interval)); cake_set_rate(&q->tins[3], rate >> 2, mtu, us_to_ns(q->target), us_to_ns(q->interval)); /* bandwidth-sharing weights */ q->tins[0].tin_quantum = quantum; q->tins[1].tin_quantum = quantum >> 4; q->tins[2].tin_quantum = quantum >> 1; q->tins[3].tin_quantum = quantum >> 2; return 0; } static int cake_config_diffserv3(struct Qdisc *sch) { /* Simplified Diffserv structure with 3 tins. * Latency Sensitive (CS7, CS6, EF, VA, TOS4) * Best Effort * Low Priority (LE, CS1) */ struct cake_sched_data *q = qdisc_priv(sch); u32 mtu = psched_mtu(qdisc_dev(sch)); u64 rate = q->rate_bps; u32 quantum = 1024; q->tin_cnt = 3; /* codepoint to class mapping */ q->tin_index = diffserv3; q->tin_order = bulk_order; /* class characteristics */ cake_set_rate(&q->tins[0], rate, mtu, us_to_ns(q->target), us_to_ns(q->interval)); cake_set_rate(&q->tins[1], rate >> 4, mtu, us_to_ns(q->target), us_to_ns(q->interval)); cake_set_rate(&q->tins[2], rate >> 2, mtu, us_to_ns(q->target), us_to_ns(q->interval)); /* bandwidth-sharing weights */ q->tins[0].tin_quantum = quantum; q->tins[1].tin_quantum = quantum >> 4; q->tins[2].tin_quantum = quantum >> 2; return 0; } static void cake_reconfigure(struct Qdisc *sch) { struct cake_sched_data *q = qdisc_priv(sch); int c, ft; switch (q->tin_mode) { case CAKE_DIFFSERV_BESTEFFORT: ft = cake_config_besteffort(sch); break; case CAKE_DIFFSERV_PRECEDENCE: ft = cake_config_precedence(sch); break; case CAKE_DIFFSERV_DIFFSERV8: ft = cake_config_diffserv8(sch); break; case CAKE_DIFFSERV_DIFFSERV4: ft = cake_config_diffserv4(sch); break; case CAKE_DIFFSERV_DIFFSERV3: default: ft = cake_config_diffserv3(sch); break; } for (c = q->tin_cnt; c < CAKE_MAX_TINS; c++) { cake_clear_tin(sch, c); q->tins[c].cparams.mtu_time = q->tins[ft].cparams.mtu_time; } q->rate_ns = q->tins[ft].tin_rate_ns; q->rate_shft = q->tins[ft].tin_rate_shft; if (q->buffer_config_limit) { q->buffer_limit = q->buffer_config_limit; } else if (q->rate_bps) { u64 t = q->rate_bps * q->interval; do_div(t, USEC_PER_SEC / 4); q->buffer_limit = max_t(u32, t, 4U << 20); } else { q->buffer_limit = ~0; } sch->flags &= ~TCQ_F_CAN_BYPASS; q->buffer_limit = min(q->buffer_limit, max(sch->limit * psched_mtu(qdisc_dev(sch)), q->buffer_config_limit)); } static int cake_change(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { struct cake_sched_data *q = qdisc_priv(sch); struct nlattr *tb[TCA_CAKE_MAX + 1]; int err; err = nla_parse_nested_deprecated(tb, TCA_CAKE_MAX, opt, cake_policy, extack); if (err < 0) return err; if (tb[TCA_CAKE_NAT]) { #if IS_ENABLED(CONFIG_NF_CONNTRACK) q->flow_mode &= ~CAKE_FLOW_NAT_FLAG; q->flow_mode |= CAKE_FLOW_NAT_FLAG * !!nla_get_u32(tb[TCA_CAKE_NAT]); #else NL_SET_ERR_MSG_ATTR(extack, tb[TCA_CAKE_NAT], "No conntrack support in kernel"); return -EOPNOTSUPP; #endif } if (tb[TCA_CAKE_BASE_RATE64]) q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]); if (tb[TCA_CAKE_DIFFSERV_MODE]) q->tin_mode = nla_get_u32(tb[TCA_CAKE_DIFFSERV_MODE]); if (tb[TCA_CAKE_WASH]) { if (!!nla_get_u32(tb[TCA_CAKE_WASH])) q->rate_flags |= CAKE_FLAG_WASH; else q->rate_flags &= ~CAKE_FLAG_WASH; } if (tb[TCA_CAKE_FLOW_MODE]) q->flow_mode = ((q->flow_mode & CAKE_FLOW_NAT_FLAG) | (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) & CAKE_FLOW_MASK)); if (tb[TCA_CAKE_ATM]) q->atm_mode = nla_get_u32(tb[TCA_CAKE_ATM]); if (tb[TCA_CAKE_OVERHEAD]) { q->rate_overhead = nla_get_s32(tb[TCA_CAKE_OVERHEAD]); q->rate_flags |= CAKE_FLAG_OVERHEAD; q->max_netlen = 0; q->max_adjlen = 0; q->min_netlen = ~0; q->min_adjlen = ~0; } if (tb[TCA_CAKE_RAW]) { q->rate_flags &= ~CAKE_FLAG_OVERHEAD; q->max_netlen = 0; q->max_adjlen = 0; q->min_netlen = ~0; q->min_adjlen = ~0; } if (tb[TCA_CAKE_MPU]) q->rate_mpu = nla_get_u32(tb[TCA_CAKE_MPU]); if (tb[TCA_CAKE_RTT]) { q->interval = nla_get_u32(tb[TCA_CAKE_RTT]); if (!q->interval) q->interval = 1; } if (tb[TCA_CAKE_TARGET]) { q->target = nla_get_u32(tb[TCA_CAKE_TARGET]); if (!q->target) q->target = 1; } if (tb[TCA_CAKE_AUTORATE]) { if (!!nla_get_u32(tb[TCA_CAKE_AUTORATE])) q->rate_flags |= CAKE_FLAG_AUTORATE_INGRESS; else q->rate_flags &= ~CAKE_FLAG_AUTORATE_INGRESS; } if (tb[TCA_CAKE_INGRESS]) { if (!!nla_get_u32(tb[TCA_CAKE_INGRESS])) q->rate_flags |= CAKE_FLAG_INGRESS; else q->rate_flags &= ~CAKE_FLAG_INGRESS; } if (tb[TCA_CAKE_ACK_FILTER]) q->ack_filter = nla_get_u32(tb[TCA_CAKE_ACK_FILTER]); if (tb[TCA_CAKE_MEMORY]) q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]); if (tb[TCA_CAKE_SPLIT_GSO]) { if (!!nla_get_u32(tb[TCA_CAKE_SPLIT_GSO])) q->rate_flags |= CAKE_FLAG_SPLIT_GSO; else q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO; } if (tb[TCA_CAKE_FWMARK]) { q->fwmark_mask = nla_get_u32(tb[TCA_CAKE_FWMARK]); q->fwmark_shft = q->fwmark_mask ? __ffs(q->fwmark_mask) : 0; } if (q->tins) { sch_tree_lock(sch); cake_reconfigure(sch); sch_tree_unlock(sch); } return 0; } static void cake_destroy(struct Qdisc *sch) { struct cake_sched_data *q = qdisc_priv(sch); qdisc_watchdog_cancel(&q->watchdog); tcf_block_put(q->block); kvfree(q->tins); } static int cake_init(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { struct cake_sched_data *q = qdisc_priv(sch); int i, j, err; sch->limit = 10240; q->tin_mode = CAKE_DIFFSERV_DIFFSERV3; q->flow_mode = CAKE_FLOW_TRIPLE; q->rate_bps = 0; /* unlimited by default */ q->interval = 100000; /* 100ms default */ q->target = 5000; /* 5ms: codel RFC argues * for 5 to 10% of interval */ q->rate_flags |= CAKE_FLAG_SPLIT_GSO; q->cur_tin = 0; q->cur_flow = 0; qdisc_watchdog_init(&q->watchdog, sch); if (opt) { err = cake_change(sch, opt, extack); if (err) return err; } err = tcf_block_get(&q->block, &q->filter_list, sch, extack); if (err) return err; quantum_div[0] = ~0; for (i = 1; i <= CAKE_QUEUES; i++) quantum_div[i] = 65535 / i; q->tins = kvcalloc(CAKE_MAX_TINS, sizeof(struct cake_tin_data), GFP_KERNEL); if (!q->tins) return -ENOMEM; for (i = 0; i < CAKE_MAX_TINS; i++) { struct cake_tin_data *b = q->tins + i; INIT_LIST_HEAD(&b->new_flows); INIT_LIST_HEAD(&b->old_flows); INIT_LIST_HEAD(&b->decaying_flows); b->sparse_flow_count = 0; b->bulk_flow_count = 0; b->decaying_flow_count = 0; for (j = 0; j < CAKE_QUEUES; j++) { struct cake_flow *flow = b->flows + j; u32 k = j * CAKE_MAX_TINS + i; INIT_LIST_HEAD(&flow->flowchain); cobalt_vars_init(&flow->cvars); q->overflow_heap[k].t = i; q->overflow_heap[k].b = j; b->overflow_idx[j] = k; } } cake_reconfigure(sch); q->avg_peak_bandwidth = q->rate_bps; q->min_netlen = ~0; q->min_adjlen = ~0; return 0; } static int cake_dump(struct Qdisc *sch, struct sk_buff *skb) { struct cake_sched_data *q = qdisc_priv(sch); struct nlattr *opts; opts = nla_nest_start_noflag(skb, TCA_OPTIONS); if (!opts) goto nla_put_failure; if (nla_put_u64_64bit(skb, TCA_CAKE_BASE_RATE64, q->rate_bps, TCA_CAKE_PAD)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_FLOW_MODE, q->flow_mode & CAKE_FLOW_MASK)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_RTT, q->interval)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_TARGET, q->target)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_MEMORY, q->buffer_config_limit)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_AUTORATE, !!(q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS))) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_INGRESS, !!(q->rate_flags & CAKE_FLAG_INGRESS))) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_NAT, !!(q->flow_mode & CAKE_FLOW_NAT_FLAG))) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_DIFFSERV_MODE, q->tin_mode)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_WASH, !!(q->rate_flags & CAKE_FLAG_WASH))) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_OVERHEAD, q->rate_overhead)) goto nla_put_failure; if (!(q->rate_flags & CAKE_FLAG_OVERHEAD)) if (nla_put_u32(skb, TCA_CAKE_RAW, 0)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_ATM, q->atm_mode)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu)) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_SPLIT_GSO, !!(q->rate_flags & CAKE_FLAG_SPLIT_GSO))) goto nla_put_failure; if (nla_put_u32(skb, TCA_CAKE_FWMARK, q->fwmark_mask)) goto nla_put_failure; return nla_nest_end(skb, opts); nla_put_failure: return -1; } static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d) { struct nlattr *stats = nla_nest_start_noflag(d->skb, TCA_STATS_APP); struct cake_sched_data *q = qdisc_priv(sch); struct nlattr *tstats, *ts; int i; if (!stats) return -1; #define PUT_STAT_U32(attr, data) do { \ if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \ goto nla_put_failure; \ } while (0) #define PUT_STAT_U64(attr, data) do { \ if (nla_put_u64_64bit(d->skb, TCA_CAKE_STATS_ ## attr, \ data, TCA_CAKE_STATS_PAD)) \ goto nla_put_failure; \ } while (0) PUT_STAT_U64(CAPACITY_ESTIMATE64, q->avg_peak_bandwidth); PUT_STAT_U32(MEMORY_LIMIT, q->buffer_limit); PUT_STAT_U32(MEMORY_USED, q->buffer_max_used); PUT_STAT_U32(AVG_NETOFF, ((q->avg_netoff + 0x8000) >> 16)); PUT_STAT_U32(MAX_NETLEN, q->max_netlen); PUT_STAT_U32(MAX_ADJLEN, q->max_adjlen); PUT_STAT_U32(MIN_NETLEN, q->min_netlen); PUT_STAT_U32(MIN_ADJLEN, q->min_adjlen); #undef PUT_STAT_U32 #undef PUT_STAT_U64 tstats = nla_nest_start_noflag(d->skb, TCA_CAKE_STATS_TIN_STATS); if (!tstats) goto nla_put_failure; #define PUT_TSTAT_U32(attr, data) do { \ if (nla_put_u32(d->skb, TCA_CAKE_TIN_STATS_ ## attr, data)) \ goto nla_put_failure; \ } while (0) #define PUT_TSTAT_U64(attr, data) do { \ if (nla_put_u64_64bit(d->skb, TCA_CAKE_TIN_STATS_ ## attr, \ data, TCA_CAKE_TIN_STATS_PAD)) \ goto nla_put_failure; \ } while (0) for (i = 0; i < q->tin_cnt; i++) { struct cake_tin_data *b = &q->tins[q->tin_order[i]]; ts = nla_nest_start_noflag(d->skb, i + 1); if (!ts) goto nla_put_failure; PUT_TSTAT_U64(THRESHOLD_RATE64, b->tin_rate_bps); PUT_TSTAT_U64(SENT_BYTES64, b->bytes); PUT_TSTAT_U32(BACKLOG_BYTES, b->tin_backlog); PUT_TSTAT_U32(TARGET_US, ktime_to_us(ns_to_ktime(b->cparams.target))); PUT_TSTAT_U32(INTERVAL_US, ktime_to_us(ns_to_ktime(b->cparams.interval))); PUT_TSTAT_U32(SENT_PACKETS, b->packets); PUT_TSTAT_U32(DROPPED_PACKETS, b->tin_dropped); PUT_TSTAT_U32(ECN_MARKED_PACKETS, b->tin_ecn_mark); PUT_TSTAT_U32(ACKS_DROPPED_PACKETS, b->ack_drops); PUT_TSTAT_U32(PEAK_DELAY_US, ktime_to_us(ns_to_ktime(b->peak_delay))); PUT_TSTAT_U32(AVG_DELAY_US, ktime_to_us(ns_to_ktime(b->avge_delay))); PUT_TSTAT_U32(BASE_DELAY_US, ktime_to_us(ns_to_ktime(b->base_delay))); PUT_TSTAT_U32(WAY_INDIRECT_HITS, b->way_hits); PUT_TSTAT_U32(WAY_MISSES, b->way_misses); PUT_TSTAT_U32(WAY_COLLISIONS, b->way_collisions); PUT_TSTAT_U32(SPARSE_FLOWS, b->sparse_flow_count + b->decaying_flow_count); PUT_TSTAT_U32(BULK_FLOWS, b->bulk_flow_count); PUT_TSTAT_U32(UNRESPONSIVE_FLOWS, b->unresponsive_flow_count); PUT_TSTAT_U32(MAX_SKBLEN, b->max_skblen); PUT_TSTAT_U32(FLOW_QUANTUM, b->flow_quantum); nla_nest_end(d->skb, ts); } #undef PUT_TSTAT_U32 #undef PUT_TSTAT_U64 nla_nest_end(d->skb, tstats); return nla_nest_end(d->skb, stats); nla_put_failure: nla_nest_cancel(d->skb, stats); return -1; } static struct Qdisc *cake_leaf(struct Qdisc *sch, unsigned long arg) { return NULL; } static unsigned long cake_find(struct Qdisc *sch, u32 classid) { return 0; } static unsigned long cake_bind(struct Qdisc *sch, unsigned long parent, u32 classid) { return 0; } static void cake_unbind(struct Qdisc *q, unsigned long cl) { } static struct tcf_block *cake_tcf_block(struct Qdisc *sch, unsigned long cl, struct netlink_ext_ack *extack) { struct cake_sched_data *q = qdisc_priv(sch); if (cl) return NULL; return q->block; } static int cake_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, struct tcmsg *tcm) { tcm->tcm_handle |= TC_H_MIN(cl); return 0; } static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl, struct gnet_dump *d) { struct cake_sched_data *q = qdisc_priv(sch); const struct cake_flow *flow = NULL; struct gnet_stats_queue qs = { 0 }; struct nlattr *stats; u32 idx = cl - 1; if (idx < CAKE_QUEUES * q->tin_cnt) { const struct cake_tin_data *b = \ &q->tins[q->tin_order[idx / CAKE_QUEUES]]; const struct sk_buff *skb; flow = &b->flows[idx % CAKE_QUEUES]; if (flow->head) { sch_tree_lock(sch); skb = flow->head; while (skb) { qs.qlen++; skb = skb->next; } sch_tree_unlock(sch); } qs.backlog = b->backlogs[idx % CAKE_QUEUES]; qs.drops = flow->dropped; } if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) return -1; if (flow) { ktime_t now = ktime_get(); stats = nla_nest_start_noflag(d->skb, TCA_STATS_APP); if (!stats) return -1; #define PUT_STAT_U32(attr, data) do { \ if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \ goto nla_put_failure; \ } while (0) #define PUT_STAT_S32(attr, data) do { \ if (nla_put_s32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \ goto nla_put_failure; \ } while (0) PUT_STAT_S32(DEFICIT, flow->deficit); PUT_STAT_U32(DROPPING, flow->cvars.dropping); PUT_STAT_U32(COBALT_COUNT, flow->cvars.count); PUT_STAT_U32(P_DROP, flow->cvars.p_drop); if (flow->cvars.p_drop) { PUT_STAT_S32(BLUE_TIMER_US, ktime_to_us( ktime_sub(now, flow->cvars.blue_timer))); } if (flow->cvars.dropping) { PUT_STAT_S32(DROP_NEXT_US, ktime_to_us( ktime_sub(now, flow->cvars.drop_next))); } if (nla_nest_end(d->skb, stats) < 0) return -1; } return 0; nla_put_failure: nla_nest_cancel(d->skb, stats); return -1; } static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg) { struct cake_sched_data *q = qdisc_priv(sch); unsigned int i, j; if (arg->stop) return; for (i = 0; i < q->tin_cnt; i++) { struct cake_tin_data *b = &q->tins[q->tin_order[i]]; for (j = 0; j < CAKE_QUEUES; j++) { if (list_empty(&b->flows[j].flowchain)) { arg->count++; continue; } if (!tc_qdisc_stats_dump(sch, i * CAKE_QUEUES + j + 1, arg)) break; } } } static const struct Qdisc_class_ops cake_class_ops = { .leaf = cake_leaf, .find = cake_find, .tcf_block = cake_tcf_block, .bind_tcf = cake_bind, .unbind_tcf = cake_unbind, .dump = cake_dump_class, .dump_stats = cake_dump_class_stats, .walk = cake_walk, }; static struct Qdisc_ops cake_qdisc_ops __read_mostly = { .cl_ops = &cake_class_ops, .id = "cake", .priv_size = sizeof(struct cake_sched_data), .enqueue = cake_enqueue, .dequeue = cake_dequeue, .peek = qdisc_peek_dequeued, .init = cake_init, .reset = cake_reset, .destroy = cake_destroy, .change = cake_change, .dump = cake_dump, .dump_stats = cake_dump_stats, .owner = THIS_MODULE, }; static int __init cake_module_init(void) { return register_qdisc(&cake_qdisc_ops); } static void __exit cake_module_exit(void) { unregister_qdisc(&cake_qdisc_ops); } module_init(cake_module_init) module_exit(cake_module_exit) MODULE_AUTHOR("Jonathan Morton"); MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("The CAKE shaper.");
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