static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q) { struct rb_node **p, *parent; struct sock *sk = skb->sk; struct rb_root *root; struct fq_flow *f; /* warning: no starvation prevention... */ if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL)) return &q->internal; /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket * or a listener (SYNCOOKIE mode) * 1) request sockets are not full blown, * they do not contain sk_pacing_rate * 2) They are not part of a 'flow' yet * 3) We do not want to rate limit them (eg SYNFLOOD attack), * especially if the listener set SO_MAX_PACING_RATE * 4) We pretend they are orphaned */ if (!sk || sk_listener(sk)) { unsigned long hash = skb_get_hash(skb) & q->orphan_mask; /* By forcing low order bit to 1, we make sure to not * collide with a local flow (socket pointers are word aligned) */ sk = (struct sock *)((hash << 1) | 1UL); skb_orphan(skb); } root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)]; if (q->flows >= (2U << q->fq_trees_log) && q->inactive_flows > q->flows/2) fq_gc(q, root, sk); p = &root->rb_node; parent = NULL; while (*p) { parent = *p; f = container_of(parent, struct fq_flow, fq_node); if (f->sk == sk) { /* socket might have been reallocated, so check * if its sk_hash is the same. * It not, we need to refill credit with * initial quantum */ if (unlikely(skb->sk && f->socket_hash != sk->sk_hash)) { f->credit = q->initial_quantum; f->socket_hash = sk->sk_hash; f->time_next_packet = 0ULL; } return f; } if (f->sk > sk) p = &parent->rb_right; else p = &parent->rb_left; } f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!f)) { q->stat_allocation_errors++; return &q->internal; } fq_flow_set_detached(f); f->sk = sk; if (skb->sk) f->socket_hash = sk->sk_hash; f->credit = q->initial_quantum; rb_link_node(&f->fq_node, parent, p); rb_insert_color(&f->fq_node, root); q->flows++; q->inactive_flows++; return f; }
static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q) { struct rb_node **p, *parent; struct sock *sk = skb->sk; struct rb_root *root; struct fq_flow *f; int band; /* warning: no starvation prevention... */ band = prio2band[skb->priority & TC_PRIO_MAX]; if (unlikely(band == 0)) return &q->internal; if (unlikely(!sk)) { /* By forcing low order bit to 1, we make sure to not * collide with a local flow (socket pointers are word aligned) */ sk = (struct sock *)(skb_get_rxhash(skb) | 1L); } root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)]; if (q->flows >= (2U << q->fq_trees_log) && q->inactive_flows > q->flows/2) fq_gc(q, root, sk); p = &root->rb_node; parent = NULL; while (*p) { parent = *p; f = container_of(parent, struct fq_flow, fq_node); if (f->sk == sk) { /* socket might have been reallocated, so check * if its sk_hash is the same. * It not, we need to refill credit with * initial quantum */ if (unlikely(skb->sk && f->socket_hash != sk->sk_hash)) { f->credit = q->initial_quantum; f->socket_hash = sk->sk_hash; } return f; } if (f->sk > sk) p = &parent->rb_right; else p = &parent->rb_left; } f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!f)) { q->stat_allocation_errors++; return &q->internal; } fq_flow_set_detached(f); f->sk = sk; if (skb->sk) f->socket_hash = sk->sk_hash; f->credit = q->initial_quantum; rb_link_node(&f->fq_node, parent, p); rb_insert_color(&f->fq_node, root); q->flows++; q->inactive_flows++; return f; }