1 files changed, 352 insertions, 0 deletions
diff --git a/kernel/bpf/tcx.c b/kernel/bpf/tcx.c
new file mode 100644
index 000000000000..13f0b5dc8262
--- /dev/null
+++ b/kernel/bpf/tcx.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Isovalent */
+
+#include <linux/bpf.h>
+#include <linux/bpf_mprog.h>
+#include <linux/netdevice.h>
+
+#include <net/tcx.h>
+
+int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	bool created, ingress = attr->attach_type == BPF_TCX_INGRESS;
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct bpf_prog *replace_prog = NULL;
+	struct net_device *dev;
+	int ret;
+
+	rtnl_lock();
+	dev = __dev_get_by_index(net, attr->target_ifindex);
+	if (!dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	if (attr->attach_flags & BPF_F_REPLACE) {
+		replace_prog = bpf_prog_get_type(attr->replace_bpf_fd,
+						 prog->type);
+		if (IS_ERR(replace_prog)) {
+			ret = PTR_ERR(replace_prog);
+			replace_prog = NULL;
+			goto out;
+		}
+	}
+	entry = tcx_entry_fetch_or_create(dev, ingress, &created);
+	if (!entry) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = bpf_mprog_attach(entry, &entry_new, prog, NULL, replace_prog,
+			       attr->attach_flags, attr->relative_fd,
+			       attr->expected_revision);
+	if (!ret) {
+		if (entry != entry_new) {
+			tcx_entry_update(dev, entry_new, ingress);
+			tcx_entry_sync();
+			tcx_skeys_inc(ingress);
+		}
+		bpf_mprog_commit(entry);
+	} else if (created) {
+		tcx_entry_free(entry);
+	}
+out:
+	if (replace_prog)
+		bpf_prog_put(replace_prog);
+	rtnl_unlock();
+	return ret;
+}
+
+int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	bool ingress = attr->attach_type == BPF_TCX_INGRESS;
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev;
+	int ret;
+
+	rtnl_lock();
+	dev = __dev_get_by_index(net, attr->target_ifindex);
+	if (!dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	entry = tcx_entry_fetch(dev, ingress);
+	if (!entry) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = bpf_mprog_detach(entry, &entry_new, prog, NULL, attr->attach_flags,
+			       attr->relative_fd, attr->expected_revision);
+	if (!ret) {
+		if (!tcx_entry_is_active(entry_new))
+			entry_new = NULL;
+		tcx_entry_update(dev, entry_new, ingress);
+		tcx_entry_sync();
+		tcx_skeys_dec(ingress);
+		bpf_mprog_commit(entry);
+		if (!entry_new)
+			tcx_entry_free(entry);
+	}
+out:
+	rtnl_unlock();
+	return ret;
+}
+
+void tcx_uninstall(struct net_device *dev, bool ingress)
+{
+	struct bpf_mprog_entry *entry, *entry_new = NULL;
+	struct bpf_tuple tuple = {};
+	struct bpf_mprog_fp *fp;
+	struct bpf_mprog_cp *cp;
+	bool active;
+
+	entry = tcx_entry_fetch(dev, ingress);
+	if (!entry)
+		return;
+	active = tcx_entry(entry)->miniq_active;
+	if (active)
+		bpf_mprog_clear_all(entry, &entry_new);
+	tcx_entry_update(dev, entry_new, ingress);
+	tcx_entry_sync();
+	bpf_mprog_foreach_tuple(entry, fp, cp, tuple) {
+		if (tuple.link)
+			tcx_link(tuple.link)->dev = NULL;
+		else
+			bpf_prog_put(tuple.prog);
+		tcx_skeys_dec(ingress);
+	}
+	if (!active)
+		tcx_entry_free(entry);
+}
+
+int tcx_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr)
+{
+	bool ingress = attr->query.attach_type == BPF_TCX_INGRESS;
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_mprog_entry *entry;
+	struct net_device *dev;
+	int ret;
+
+	rtnl_lock();
+	dev = __dev_get_by_index(net, attr->query.target_ifindex);
+	if (!dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	entry = tcx_entry_fetch(dev, ingress);
+	if (!entry) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = bpf_mprog_query(attr, uattr, entry);
+out:
+	rtnl_unlock();
+	return ret;
+}
+
+static int tcx_link_prog_attach(struct bpf_link *link, u32 flags, u32 id_or_fd,
+				u64 revision)
+{
+	struct tcx_link *tcx = tcx_link(link);
+	bool created, ingress = tcx->location == BPF_TCX_INGRESS;
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev = tcx->dev;
+	int ret;
+
+	ASSERT_RTNL();
+	entry = tcx_entry_fetch_or_create(dev, ingress, &created);
+	if (!entry)
+		return -ENOMEM;
+	ret = bpf_mprog_attach(entry, &entry_new, link->prog, link, NULL, flags,
+			       id_or_fd, revision);
+	if (!ret) {
+		if (entry != entry_new) {
+			tcx_entry_update(dev, entry_new, ingress);
+			tcx_entry_sync();
+			tcx_skeys_inc(ingress);
+		}
+		bpf_mprog_commit(entry);
+	} else if (created) {
+		tcx_entry_free(entry);
+	}
+	return ret;
+}
+
+static void tcx_link_release(struct bpf_link *link)
+{
+	struct tcx_link *tcx = tcx_link(link);
+	bool ingress = tcx->location == BPF_TCX_INGRESS;
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+	dev = tcx->dev;
+	if (!dev)
+		goto out;
+	entry = tcx_entry_fetch(dev, ingress);
+	if (!entry) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = bpf_mprog_detach(entry, &entry_new, link->prog, link, 0, 0, 0);
+	if (!ret) {
+		if (!tcx_entry_is_active(entry_new))
+			entry_new = NULL;
+		tcx_entry_update(dev, entry_new, ingress);
+		tcx_entry_sync();
+		tcx_skeys_dec(ingress);
+		bpf_mprog_commit(entry);
+		if (!entry_new)
+			tcx_entry_free(entry);
+		tcx->dev = NULL;
+	}
+out:
+	WARN_ON_ONCE(ret);
+	rtnl_unlock();
+}
+
+static int tcx_link_update(struct bpf_link *link, struct bpf_prog *nprog,
+			   struct bpf_prog *oprog)
+{
+	struct tcx_link *tcx = tcx_link(link);
+	bool ingress = tcx->location == BPF_TCX_INGRESS;
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+	dev = tcx->dev;
+	if (!dev) {
+		ret = -ENOLINK;
+		goto out;
+	}
+	if (oprog && link->prog != oprog) {
+		ret = -EPERM;
+		goto out;
+	}
+	oprog = link->prog;
+	if (oprog == nprog) {
+		bpf_prog_put(nprog);
+		goto out;
+	}
+	entry = tcx_entry_fetch(dev, ingress);
+	if (!entry) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = bpf_mprog_attach(entry, &entry_new, nprog, link, oprog,
+			       BPF_F_REPLACE | BPF_F_ID,
+			       link->prog->aux->id, 0);
+	if (!ret) {
+		WARN_ON_ONCE(entry != entry_new);
+		oprog = xchg(&link->prog, nprog);
+		bpf_prog_put(oprog);
+		bpf_mprog_commit(entry);
+	}
+out:
+	rtnl_unlock();
+	return ret;
+}
+
+static void tcx_link_dealloc(struct bpf_link *link)
+{
+	kfree(tcx_link(link));
+}
+
+static void tcx_link_fdinfo(const struct bpf_link *link, struct seq_file *seq)
+{
+	const struct tcx_link *tcx = tcx_link_const(link);
+	u32 ifindex = 0;
+
+	rtnl_lock();
+	if (tcx->dev)
+		ifindex = tcx->dev->ifindex;
+	rtnl_unlock();
+
+	seq_printf(seq, "ifindex:\t%u\n", ifindex);
+	seq_printf(seq, "attach_type:\t%u (%s)\n",
+		   tcx->location,
+		   tcx->location == BPF_TCX_INGRESS ? "ingress" : "egress");
+}
+
+static int tcx_link_fill_info(const struct bpf_link *link,
+			      struct bpf_link_info *info)
+{
+	const struct tcx_link *tcx = tcx_link_const(link);
+	u32 ifindex = 0;
+
+	rtnl_lock();
+	if (tcx->dev)
+		ifindex = tcx->dev->ifindex;
+	rtnl_unlock();
+
+	info->tcx.ifindex = ifindex;
+	info->tcx.attach_type = tcx->location;
+	return 0;
+}
+
+static int tcx_link_detach(struct bpf_link *link)
+{
+	tcx_link_release(link);
+	return 0;
+}
+
+static const struct bpf_link_ops tcx_link_lops = {
+	.release	= tcx_link_release,
+	.detach		= tcx_link_detach,
+	.dealloc	= tcx_link_dealloc,
+	.update_prog	= tcx_link_update,
+	.show_fdinfo	= tcx_link_fdinfo,
+	.fill_link_info	= tcx_link_fill_info,
+};
+
+static int tcx_link_init(struct tcx_link *tcx,
+			 struct bpf_link_primer *link_primer,
+			 const union bpf_attr *attr,
+			 struct net_device *dev,
+			 struct bpf_prog *prog)
+{
+	bpf_link_init(&tcx->link, BPF_LINK_TYPE_TCX, &tcx_link_lops, prog);
+	tcx->location = attr->link_create.attach_type;
+	tcx->dev = dev;
+	return bpf_link_prime(&tcx->link, link_primer);
+}
+
+int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_link_primer link_primer;
+	struct net_device *dev;
+	struct tcx_link *tcx;
+	int ret;
+
+	rtnl_lock();
+	dev = __dev_get_by_index(net, attr->link_create.target_ifindex);
+	if (!dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	tcx = kzalloc(sizeof(*tcx), GFP_USER);
+	if (!tcx) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = tcx_link_init(tcx, &link_primer, attr, dev, prog);
+	if (ret) {
+		kfree(tcx);
+		goto out;
+	}
+	ret = tcx_link_prog_attach(&tcx->link, attr->link_create.flags,
+				   attr->link_create.tcx.relative_fd,
+				   attr->link_create.tcx.expected_revision);
+	if (ret) {
+		tcx->dev = NULL;
+		bpf_link_cleanup(&link_primer);
+		goto out;
+	}
+	ret = bpf_link_settle(&link_primer);
+out:
+	rtnl_unlock();
+	return ret;
+}