1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <vmlinux.h>
4 #include "bpf_experimental.h"
5 #include "bpf_qdisc_common.h"
6
7 char _license[] SEC("license") = "GPL";
8
9 struct skb_node {
10 struct sk_buff __kptr * skb;
11 struct bpf_list_node node;
12 };
13
14 private(A) struct bpf_spin_lock q_fifo_lock;
15 private(A) struct bpf_list_head q_fifo __contains(skb_node, node);
16
17 bool init_called;
18
19 SEC("struct_ops/bpf_fifo_enqueue")
BPF_PROG(bpf_fifo_enqueue,struct sk_buff * skb,struct Qdisc * sch,struct bpf_sk_buff_ptr * to_free)20 int BPF_PROG(bpf_fifo_enqueue, struct sk_buff *skb, struct Qdisc *sch,
21 struct bpf_sk_buff_ptr *to_free)
22 {
23 struct skb_node *skbn;
24 u32 pkt_len;
25
26 if (sch->q.qlen == sch->limit)
27 goto drop;
28
29 skbn = bpf_obj_new(typeof(*skbn));
30 if (!skbn)
31 goto drop;
32
33 pkt_len = qdisc_pkt_len(skb);
34
35 sch->q.qlen++;
36 skb = bpf_kptr_xchg(&skbn->skb, skb);
37 if (skb)
38 bpf_qdisc_skb_drop(skb, to_free);
39
40 bpf_spin_lock(&q_fifo_lock);
41 bpf_list_push_back(&q_fifo, &skbn->node);
42 bpf_spin_unlock(&q_fifo_lock);
43
44 sch->qstats.backlog += pkt_len;
45 return NET_XMIT_SUCCESS;
46 drop:
47 bpf_qdisc_skb_drop(skb, to_free);
48 return NET_XMIT_DROP;
49 }
50
51 SEC("struct_ops/bpf_fifo_dequeue")
BPF_PROG(bpf_fifo_dequeue,struct Qdisc * sch)52 struct sk_buff *BPF_PROG(bpf_fifo_dequeue, struct Qdisc *sch)
53 {
54 struct bpf_list_node *node;
55 struct sk_buff *skb = NULL;
56 struct skb_node *skbn;
57
58 bpf_spin_lock(&q_fifo_lock);
59 node = bpf_list_pop_front(&q_fifo);
60 bpf_spin_unlock(&q_fifo_lock);
61 if (!node)
62 return NULL;
63
64 skbn = container_of(node, struct skb_node, node);
65 skb = bpf_kptr_xchg(&skbn->skb, skb);
66 bpf_obj_drop(skbn);
67 if (!skb)
68 return NULL;
69
70 sch->qstats.backlog -= qdisc_pkt_len(skb);
71 bpf_qdisc_bstats_update(sch, skb);
72 sch->q.qlen--;
73
74 return skb;
75 }
76
77 SEC("struct_ops/bpf_fifo_init")
BPF_PROG(bpf_fifo_init,struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)78 int BPF_PROG(bpf_fifo_init, struct Qdisc *sch, struct nlattr *opt,
79 struct netlink_ext_ack *extack)
80 {
81 sch->limit = 1000;
82 init_called = true;
83 return 0;
84 }
85
86 SEC("struct_ops/bpf_fifo_reset")
BPF_PROG(bpf_fifo_reset,struct Qdisc * sch)87 void BPF_PROG(bpf_fifo_reset, struct Qdisc *sch)
88 {
89 struct bpf_list_node *node;
90 struct skb_node *skbn;
91 int i;
92
93 bpf_for(i, 0, sch->q.qlen) {
94 struct sk_buff *skb = NULL;
95
96 bpf_spin_lock(&q_fifo_lock);
97 node = bpf_list_pop_front(&q_fifo);
98 bpf_spin_unlock(&q_fifo_lock);
99
100 if (!node)
101 break;
102
103 skbn = container_of(node, struct skb_node, node);
104 skb = bpf_kptr_xchg(&skbn->skb, skb);
105 if (skb)
106 bpf_kfree_skb(skb);
107 bpf_obj_drop(skbn);
108 }
109 sch->q.qlen = 0;
110 }
111
112 SEC("struct_ops")
BPF_PROG(bpf_fifo_destroy,struct Qdisc * sch)113 void BPF_PROG(bpf_fifo_destroy, struct Qdisc *sch)
114 {
115 }
116
117 SEC(".struct_ops")
118 struct Qdisc_ops fifo = {
119 .enqueue = (void *)bpf_fifo_enqueue,
120 .dequeue = (void *)bpf_fifo_dequeue,
121 .init = (void *)bpf_fifo_init,
122 .reset = (void *)bpf_fifo_reset,
123 .destroy = (void *)bpf_fifo_destroy,
124 .id = "bpf_fifo",
125 };
126
127