This selftest shows a bare minimum fifo qdisc, which simply enqueues skbs
into the back of a bpf list and dequeues from the front of the list.
Signed-off-by: Amery Hung <amery.hung@xxxxxxxxxxxxx>
---
tools/testing/selftests/bpf/config | 1 +
.../selftests/bpf/prog_tests/bpf_qdisc.c | 161 ++++++++++++++++++
.../selftests/bpf/progs/bpf_qdisc_common.h | 27 +++
.../selftests/bpf/progs/bpf_qdisc_fifo.c | 117 +++++++++++++
4 files changed, 306 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c
create mode 100644 tools/testing/selftests/bpf/progs/bpf_qdisc_common.h
create mode 100644 tools/testing/selftests/bpf/progs/bpf_qdisc_fifo.c
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index 4ca84c8d9116..cf35e7e473d4 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -70,6 +70,7 @@ CONFIG_NET_IPGRE=y
CONFIG_NET_IPGRE_DEMUX=y
CONFIG_NET_IPIP=y
CONFIG_NET_MPLS_GSO=y
+CONFIG_NET_SCH_BPF=y
CONFIG_NET_SCH_FQ=y
CONFIG_NET_SCH_INGRESS=y
CONFIG_NET_SCHED=y
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c b/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c
new file mode 100644
index 000000000000..295d0216e70f
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c
@@ -0,0 +1,161 @@
+#include <linux/pkt_sched.h>
+#include <linux/rtnetlink.h>
+#include <test_progs.h>
+
+#include "network_helpers.h"
+#include "bpf_qdisc_fifo.skel.h"
+
+#ifndef ENOTSUPP
+#define ENOTSUPP 524
+#endif
+
+#define LO_IFINDEX 1
+
+static const unsigned int total_bytes = 10 * 1024 * 1024;
+static int stop;
+
+static void *server(void *arg)
+{
+ int lfd = (int)(long)arg, err = 0, fd;
+ ssize_t nr_sent = 0, bytes = 0;
+ char batch[1500];
+
+ fd = accept(lfd, NULL, NULL);
+ while (fd == -1) {
+ if (errno == EINTR)
+ continue;
+ err = -errno;
+ goto done;
+ }
+
+ if (settimeo(fd, 0)) {
+ err = -errno;
+ goto done;
+ }
+
+ while (bytes < total_bytes && !READ_ONCE(stop)) {
+ nr_sent = send(fd, &batch,
+ MIN(total_bytes - bytes, sizeof(batch)), 0);
+ if (nr_sent == -1 && errno == EINTR)
+ continue;
+ if (nr_sent == -1) {
+ err = -errno;
+ break;
+ }
+ bytes += nr_sent;
+ }
+
+ ASSERT_EQ(bytes, total_bytes, "send");
+
+done:
+ if (fd >= 0)
+ close(fd);
+ if (err) {
+ WRITE_ONCE(stop, 1);
+ return ERR_PTR(err);
+ }
+ return NULL;
+}
+
+static void do_test(char *qdisc)
+{
+ DECLARE_LIBBPF_OPTS(bpf_tc_hook, hook, .ifindex = LO_IFINDEX,
+ .attach_point = BPF_TC_QDISC,
+ .parent = TC_H_ROOT,
+ .handle = 0x8000000,
+ .qdisc = qdisc);
+ struct sockaddr_in6 sa6 = {};
+ ssize_t nr_recv = 0, bytes = 0;
+ int lfd = -1, fd = -1;
+ pthread_t srv_thread;
+ socklen_t addrlen = sizeof(sa6);
+ void *thread_ret;
+ char batch[1500];
+ int err;
+
+ WRITE_ONCE(stop, 0);
+
+ err = bpf_tc_hook_create(&hook);
+ if (!ASSERT_OK(err, "attach qdisc"))
+ return;
+
+ lfd = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
+ if (!ASSERT_NEQ(lfd, -1, "socket")) {
+ bpf_tc_hook_destroy(&hook);
+ return;
+ }
+
+ fd = socket(AF_INET6, SOCK_STREAM, 0);
+ if (!ASSERT_NEQ(fd, -1, "socket")) {
+ bpf_tc_hook_destroy(&hook);
+ close(lfd);
+ return;
+ }
+
+ if (settimeo(lfd, 0) || settimeo(fd, 0))
+ goto done;
+
+ err = getsockname(lfd, (struct sockaddr *)&sa6, &addrlen);
+ if (!ASSERT_NEQ(err, -1, "getsockname"))
+ goto done;
+
+ /* connect to server */
+ err = connect(fd, (struct sockaddr *)&sa6, addrlen);
+ if (!ASSERT_NEQ(err, -1, "connect"))
+ goto done;
+
+ err = pthread_create(&srv_thread, NULL, server, (void *)(long)lfd);
+ if (!ASSERT_OK(err, "pthread_create"))
+ goto done;
+
+ /* recv total_bytes */
+ while (bytes < total_bytes && !READ_ONCE(stop)) {
+ nr_recv = recv(fd, &batch,
+ MIN(total_bytes - bytes, sizeof(batch)), 0);
+ if (nr_recv == -1 && errno == EINTR)
+ continue;
+ if (nr_recv == -1)
+ break;
+ bytes += nr_recv;
+ }
+
+ ASSERT_EQ(bytes, total_bytes, "recv");
+
+ WRITE_ONCE(stop, 1);
+ pthread_join(srv_thread, &thread_ret);
+ ASSERT_OK(IS_ERR(thread_ret), "thread_ret");
+
+done:
+ close(lfd);
+ close(fd);
+
+ bpf_tc_hook_destroy(&hook);
+ return;
+}
+
+static void test_fifo(void)
+{
+ struct bpf_qdisc_fifo *fifo_skel;
+ struct bpf_link *link;
+
+ fifo_skel = bpf_qdisc_fifo__open_and_load();
+ if (!ASSERT_OK_PTR(fifo_skel, "bpf_qdisc_fifo__open_and_load"))
+ return;
+
+ link = bpf_map__attach_struct_ops(fifo_skel->maps.fifo);
+ if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops")) {
+ bpf_qdisc_fifo__destroy(fifo_skel);
+ return;
+ }
+
+ do_test("bpf_fifo");
+
+ bpf_link__destroy(link);
+ bpf_qdisc_fifo__destroy(fifo_skel);
+}
+
+void test_bpf_qdisc(void)
+{
+ if (test__start_subtest("fifo"))
+ test_fifo();
+}
diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h b/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h
new file mode 100644
index 000000000000..62a778f94908
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h
@@ -0,0 +1,27 @@
+#ifndef _BPF_QDISC_COMMON_H
+#define _BPF_QDISC_COMMON_H
+
+#define NET_XMIT_SUCCESS 0x00
+#define NET_XMIT_DROP 0x01 /* skb dropped */
+#define NET_XMIT_CN 0x02 /* congestion notification */
+
+#define TC_PRIO_CONTROL 7
+#define TC_PRIO_MAX 15
+
+u32 bpf_skb_get_hash(struct sk_buff *p) __ksym;
+void bpf_kfree_skb(struct sk_buff *p) __ksym;
+void bpf_qdisc_skb_drop(struct sk_buff *p, struct bpf_sk_buff_ptr *to_free) __ksym;
+void bpf_qdisc_watchdog_schedule(struct Qdisc *sch, u64 expire, u64 delta_ns) __ksym;
+void bpf_qdisc_bstats_update(struct Qdisc *sch, const struct sk_buff *skb) __ksym;
+
+static struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
+{
+ return (struct qdisc_skb_cb *)skb->cb;
+}
+
+static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
+{
+ return qdisc_skb_cb(skb)->pkt_len;
+}
+
+#endif
diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_fifo.c b/tools/testing/selftests/bpf/progs/bpf_qdisc_fifo.c
new file mode 100644
index 000000000000..705e7da325da
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_fifo.c
@@ -0,0 +1,117 @@
+#include <vmlinux.h>
+#include "bpf_experimental.h"
+#include "bpf_qdisc_common.h"
+
+char _license[] SEC("license") = "GPL";
+
+struct skb_node {
+ struct sk_buff __kptr * skb;
+ struct bpf_list_node node;
+};
+
+#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
+
+private(A) struct bpf_spin_lock q_fifo_lock;
+private(A) struct bpf_list_head q_fifo __contains(skb_node, node);
+
+SEC("struct_ops/bpf_fifo_enqueue")
+int BPF_PROG(bpf_fifo_enqueue, struct sk_buff *skb, struct Qdisc *sch,
+ struct bpf_sk_buff_ptr *to_free)
+{
+ struct skb_node *skbn;
+ u32 pkt_len;
+
+ if (sch->q.qlen == sch->limit)
+ goto drop;
+
+ skbn = bpf_obj_new(typeof(*skbn));
+ if (!skbn)
+ goto drop;
+
+ pkt_len = qdisc_pkt_len(skb);
+
+ sch->q.qlen++;
+ skb = bpf_kptr_xchg(&skbn->skb, skb);
+ if (skb)
+ bpf_qdisc_skb_drop(skb, to_free);
+
+ bpf_spin_lock(&q_fifo_lock);
+ bpf_list_push_back(&q_fifo, &skbn->node);
+ bpf_spin_unlock(&q_fifo_lock);
+
+ sch->qstats.backlog += pkt_len;
+ return NET_XMIT_SUCCESS;
+drop:
+ bpf_qdisc_skb_drop(skb, to_free);
+ return NET_XMIT_DROP;
+}
+
+SEC("struct_ops/bpf_fifo_dequeue")
+struct sk_buff *BPF_PROG(bpf_fifo_dequeue, struct Qdisc *sch)
+{
+ struct bpf_list_node *node;
+ struct sk_buff *skb = NULL;
+ struct skb_node *skbn;
+
+ bpf_spin_lock(&q_fifo_lock);
+ node = bpf_list_pop_front(&q_fifo);
+ bpf_spin_unlock(&q_fifo_lock);
+ if (!node)
+ return NULL;
+
+ skbn = container_of(node, struct skb_node, node);
+ skb = bpf_kptr_xchg(&skbn->skb, skb);
+ bpf_obj_drop(skbn);
+ if (!skb)
+ return NULL;
+
+ sch->qstats.backlog -= qdisc_pkt_len(skb);
+ bpf_qdisc_bstats_update(sch, skb);
+ sch->q.qlen--;
+
+ return skb;
+}
+
+SEC("struct_ops/bpf_fifo_init")
+int BPF_PROG(bpf_fifo_init, struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ sch->limit = 1000;
+ return 0;
+}
+
+SEC("struct_ops/bpf_fifo_reset")
+void BPF_PROG(bpf_fifo_reset, struct Qdisc *sch)
+{
+ struct bpf_list_node *node;
+ struct skb_node *skbn;
+ int i;
+
+ bpf_for(i, 0, sch->q.qlen) {
+ struct sk_buff *skb = NULL;
+
+ bpf_spin_lock(&q_fifo_lock);
+ node = bpf_list_pop_front(&q_fifo);
+ bpf_spin_unlock(&q_fifo_lock);
+
+ if (!node)
+ break;
+
+ skbn = container_of(node, struct skb_node, node);
+ skb = bpf_kptr_xchg(&skbn->skb, skb);
+ if (skb)
+ bpf_kfree_skb(skb);
+ bpf_obj_drop(skbn);
+ }
+ sch->q.qlen = 0;
+}
+
+SEC(".struct_ops")
+struct Qdisc_ops fifo = {
+ .enqueue = (void *)bpf_fifo_enqueue,
+ .dequeue = (void *)bpf_fifo_dequeue,
+ .init = (void *)bpf_fifo_init,
+ .reset = (void *)bpf_fifo_reset,
+ .id = "bpf_fifo",
+};
+
--
2.20.1
