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-rw-r--r--kernel/bpf/tcx.c346
1 files changed, 346 insertions, 0 deletions
diff --git a/kernel/bpf/tcx.c b/kernel/bpf/tcx.c
new file mode 100644
index 0000000000..1338a13a8b
--- /dev/null
+++ b/kernel/bpf/tcx.c
@@ -0,0 +1,346 @@
+// 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 net_device *dev;
+ int ret;
+
+ rtnl_lock();
+ dev = __dev_get_by_index(net, attr->query.target_ifindex);
+ if (!dev) {
+ ret = -ENODEV;
+ goto out;
+ }
+ ret = bpf_mprog_query(attr, uattr, tcx_entry_fetch(dev, ingress));
+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;
+}