Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c
new file mode 100644
index 0000000..542f275
--- /dev/null
+++ b/kernel/bpf/net_namespace.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <net/net_namespace.h>
+
+/*
+ * Functions to manage BPF programs attached to netns
+ */
+
+struct bpf_netns_link {
+ struct bpf_link link;
+ enum bpf_attach_type type;
+ enum netns_bpf_attach_type netns_type;
+
+ /* We don't hold a ref to net in order to auto-detach the link
+ * when netns is going away. Instead we rely on pernet
+ * pre_exit callback to clear this pointer. Must be accessed
+ * with netns_bpf_mutex held.
+ */
+ struct net *net;
+ struct list_head node; /* node in list of links attached to net */
+};
+
+/* Protects updates to netns_bpf */
+DEFINE_MUTEX(netns_bpf_mutex);
+
+static void netns_bpf_attach_type_unneed(enum netns_bpf_attach_type type)
+{
+ switch (type) {
+#ifdef CONFIG_INET
+ case NETNS_BPF_SK_LOOKUP:
+ static_branch_dec(&bpf_sk_lookup_enabled);
+ break;
+#endif
+ default:
+ break;
+ }
+}
+
+static void netns_bpf_attach_type_need(enum netns_bpf_attach_type type)
+{
+ switch (type) {
+#ifdef CONFIG_INET
+ case NETNS_BPF_SK_LOOKUP:
+ static_branch_inc(&bpf_sk_lookup_enabled);
+ break;
+#endif
+ default:
+ break;
+ }
+}
+
+/* Must be called with netns_bpf_mutex held. */
+static void netns_bpf_run_array_detach(struct net *net,
+ enum netns_bpf_attach_type type)
+{
+ struct bpf_prog_array *run_array;
+
+ run_array = rcu_replace_pointer(net->bpf.run_array[type], NULL,
+ lockdep_is_held(&netns_bpf_mutex));
+ bpf_prog_array_free(run_array);
+}
+
+static int link_index(struct net *net, enum netns_bpf_attach_type type,
+ struct bpf_netns_link *link)
+{
+ struct bpf_netns_link *pos;
+ int i = 0;
+
+ list_for_each_entry(pos, &net->bpf.links[type], node) {
+ if (pos == link)
+ return i;
+ i++;
+ }
+ return -ENOENT;
+}
+
+static int link_count(struct net *net, enum netns_bpf_attach_type type)
+{
+ struct list_head *pos;
+ int i = 0;
+
+ list_for_each(pos, &net->bpf.links[type])
+ i++;
+ return i;
+}
+
+static void fill_prog_array(struct net *net, enum netns_bpf_attach_type type,
+ struct bpf_prog_array *prog_array)
+{
+ struct bpf_netns_link *pos;
+ unsigned int i = 0;
+
+ list_for_each_entry(pos, &net->bpf.links[type], node) {
+ prog_array->items[i].prog = pos->link.prog;
+ i++;
+ }
+}
+
+static void bpf_netns_link_release(struct bpf_link *link)
+{
+ struct bpf_netns_link *net_link =
+ container_of(link, struct bpf_netns_link, link);
+ enum netns_bpf_attach_type type = net_link->netns_type;
+ struct bpf_prog_array *old_array, *new_array;
+ struct net *net;
+ int cnt, idx;
+
+ mutex_lock(&netns_bpf_mutex);
+
+ /* We can race with cleanup_net, but if we see a non-NULL
+ * struct net pointer, pre_exit has not run yet and wait for
+ * netns_bpf_mutex.
+ */
+ net = net_link->net;
+ if (!net)
+ goto out_unlock;
+
+ /* Mark attach point as unused */
+ netns_bpf_attach_type_unneed(type);
+
+ /* Remember link position in case of safe delete */
+ idx = link_index(net, type, net_link);
+ list_del(&net_link->node);
+
+ cnt = link_count(net, type);
+ if (!cnt) {
+ netns_bpf_run_array_detach(net, type);
+ goto out_unlock;
+ }
+
+ old_array = rcu_dereference_protected(net->bpf.run_array[type],
+ lockdep_is_held(&netns_bpf_mutex));
+ new_array = bpf_prog_array_alloc(cnt, GFP_KERNEL);
+ if (!new_array) {
+ WARN_ON(bpf_prog_array_delete_safe_at(old_array, idx));
+ goto out_unlock;
+ }
+ fill_prog_array(net, type, new_array);
+ rcu_assign_pointer(net->bpf.run_array[type], new_array);
+ bpf_prog_array_free(old_array);
+
+out_unlock:
+ net_link->net = NULL;
+ mutex_unlock(&netns_bpf_mutex);
+}
+
+static int bpf_netns_link_detach(struct bpf_link *link)
+{
+ bpf_netns_link_release(link);
+ return 0;
+}
+
+static void bpf_netns_link_dealloc(struct bpf_link *link)
+{
+ struct bpf_netns_link *net_link =
+ container_of(link, struct bpf_netns_link, link);
+
+ kfree(net_link);
+}
+
+static int bpf_netns_link_update_prog(struct bpf_link *link,
+ struct bpf_prog *new_prog,
+ struct bpf_prog *old_prog)
+{
+ struct bpf_netns_link *net_link =
+ container_of(link, struct bpf_netns_link, link);
+ enum netns_bpf_attach_type type = net_link->netns_type;
+ struct bpf_prog_array *run_array;
+ struct net *net;
+ int idx, ret;
+
+ if (old_prog && old_prog != link->prog)
+ return -EPERM;
+ if (new_prog->type != link->prog->type)
+ return -EINVAL;
+
+ mutex_lock(&netns_bpf_mutex);
+
+ net = net_link->net;
+ if (!net || !check_net(net)) {
+ /* Link auto-detached or netns dying */
+ ret = -ENOLINK;
+ goto out_unlock;
+ }
+
+ run_array = rcu_dereference_protected(net->bpf.run_array[type],
+ lockdep_is_held(&netns_bpf_mutex));
+ idx = link_index(net, type, net_link);
+ ret = bpf_prog_array_update_at(run_array, idx, new_prog);
+ if (ret)
+ goto out_unlock;
+
+ old_prog = xchg(&link->prog, new_prog);
+ bpf_prog_put(old_prog);
+
+out_unlock:
+ mutex_unlock(&netns_bpf_mutex);
+ return ret;
+}
+
+static int bpf_netns_link_fill_info(const struct bpf_link *link,
+ struct bpf_link_info *info)
+{
+ const struct bpf_netns_link *net_link =
+ container_of(link, struct bpf_netns_link, link);
+ unsigned int inum = 0;
+ struct net *net;
+
+ mutex_lock(&netns_bpf_mutex);
+ net = net_link->net;
+ if (net && check_net(net))
+ inum = net->ns.inum;
+ mutex_unlock(&netns_bpf_mutex);
+
+ info->netns.netns_ino = inum;
+ info->netns.attach_type = net_link->type;
+ return 0;
+}
+
+static void bpf_netns_link_show_fdinfo(const struct bpf_link *link,
+ struct seq_file *seq)
+{
+ struct bpf_link_info info = {};
+
+ bpf_netns_link_fill_info(link, &info);
+ seq_printf(seq,
+ "netns_ino:\t%u\n"
+ "attach_type:\t%u\n",
+ info.netns.netns_ino,
+ info.netns.attach_type);
+}
+
+static const struct bpf_link_ops bpf_netns_link_ops = {
+ .release = bpf_netns_link_release,
+ .dealloc = bpf_netns_link_dealloc,
+ .detach = bpf_netns_link_detach,
+ .update_prog = bpf_netns_link_update_prog,
+ .fill_link_info = bpf_netns_link_fill_info,
+ .show_fdinfo = bpf_netns_link_show_fdinfo,
+};
+
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_query(const union bpf_attr *attr,
+ union bpf_attr __user *uattr,
+ struct net *net,
+ enum netns_bpf_attach_type type)
+{
+ __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
+ struct bpf_prog_array *run_array;
+ u32 prog_cnt = 0, flags = 0;
+
+ run_array = rcu_dereference_protected(net->bpf.run_array[type],
+ lockdep_is_held(&netns_bpf_mutex));
+ if (run_array)
+ prog_cnt = bpf_prog_array_length(run_array);
+
+ if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+ return -EFAULT;
+ if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
+ return -EFAULT;
+ if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
+ return 0;
+
+ return bpf_prog_array_copy_to_user(run_array, prog_ids,
+ attr->query.prog_cnt);
+}
+
+int netns_bpf_prog_query(const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ enum netns_bpf_attach_type type;
+ struct net *net;
+ int ret;
+
+ if (attr->query.query_flags)
+ return -EINVAL;
+
+ type = to_netns_bpf_attach_type(attr->query.attach_type);
+ if (type < 0)
+ return -EINVAL;
+
+ net = get_net_ns_by_fd(attr->query.target_fd);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ mutex_lock(&netns_bpf_mutex);
+ ret = __netns_bpf_prog_query(attr, uattr, net, type);
+ mutex_unlock(&netns_bpf_mutex);
+
+ put_net(net);
+ return ret;
+}
+
+int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+ struct bpf_prog_array *run_array;
+ enum netns_bpf_attach_type type;
+ struct bpf_prog *attached;
+ struct net *net;
+ int ret;
+
+ if (attr->target_fd || attr->attach_flags || attr->replace_bpf_fd)
+ return -EINVAL;
+
+ type = to_netns_bpf_attach_type(attr->attach_type);
+ if (type < 0)
+ return -EINVAL;
+
+ net = current->nsproxy->net_ns;
+ mutex_lock(&netns_bpf_mutex);
+
+ /* Attaching prog directly is not compatible with links */
+ if (!list_empty(&net->bpf.links[type])) {
+ ret = -EEXIST;
+ goto out_unlock;
+ }
+
+ switch (type) {
+ case NETNS_BPF_FLOW_DISSECTOR:
+ ret = flow_dissector_bpf_prog_attach_check(net, prog);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ if (ret)
+ goto out_unlock;
+
+ attached = net->bpf.progs[type];
+ if (attached == prog) {
+ /* The same program cannot be attached twice */
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ run_array = rcu_dereference_protected(net->bpf.run_array[type],
+ lockdep_is_held(&netns_bpf_mutex));
+ if (run_array) {
+ WRITE_ONCE(run_array->items[0].prog, prog);
+ } else {
+ run_array = bpf_prog_array_alloc(1, GFP_KERNEL);
+ if (!run_array) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+ run_array->items[0].prog = prog;
+ rcu_assign_pointer(net->bpf.run_array[type], run_array);
+ }
+
+ net->bpf.progs[type] = prog;
+ if (attached)
+ bpf_prog_put(attached);
+
+out_unlock:
+ mutex_unlock(&netns_bpf_mutex);
+
+ return ret;
+}
+
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_detach(struct net *net,
+ enum netns_bpf_attach_type type,
+ struct bpf_prog *old)
+{
+ struct bpf_prog *attached;
+
+ /* Progs attached via links cannot be detached */
+ if (!list_empty(&net->bpf.links[type]))
+ return -EINVAL;
+
+ attached = net->bpf.progs[type];
+ if (!attached || attached != old)
+ return -ENOENT;
+ netns_bpf_run_array_detach(net, type);
+ net->bpf.progs[type] = NULL;
+ bpf_prog_put(attached);
+ return 0;
+}
+
+int netns_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
+{
+ enum netns_bpf_attach_type type;
+ struct bpf_prog *prog;
+ int ret;
+
+ if (attr->target_fd)
+ return -EINVAL;
+
+ type = to_netns_bpf_attach_type(attr->attach_type);
+ if (type < 0)
+ return -EINVAL;
+
+ prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ mutex_lock(&netns_bpf_mutex);
+ ret = __netns_bpf_prog_detach(current->nsproxy->net_ns, type, prog);
+ mutex_unlock(&netns_bpf_mutex);
+
+ bpf_prog_put(prog);
+
+ return ret;
+}
+
+static int netns_bpf_max_progs(enum netns_bpf_attach_type type)
+{
+ switch (type) {
+ case NETNS_BPF_FLOW_DISSECTOR:
+ return 1;
+ case NETNS_BPF_SK_LOOKUP:
+ return 64;
+ default:
+ return 0;
+ }
+}
+
+static int netns_bpf_link_attach(struct net *net, struct bpf_link *link,
+ enum netns_bpf_attach_type type)
+{
+ struct bpf_netns_link *net_link =
+ container_of(link, struct bpf_netns_link, link);
+ struct bpf_prog_array *run_array;
+ int cnt, err;
+
+ mutex_lock(&netns_bpf_mutex);
+
+ cnt = link_count(net, type);
+ if (cnt >= netns_bpf_max_progs(type)) {
+ err = -E2BIG;
+ goto out_unlock;
+ }
+ /* Links are not compatible with attaching prog directly */
+ if (net->bpf.progs[type]) {
+ err = -EEXIST;
+ goto out_unlock;
+ }
+
+ switch (type) {
+ case NETNS_BPF_FLOW_DISSECTOR:
+ err = flow_dissector_bpf_prog_attach_check(net, link->prog);
+ break;
+ case NETNS_BPF_SK_LOOKUP:
+ err = 0; /* nothing to check */
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+ if (err)
+ goto out_unlock;
+
+ run_array = bpf_prog_array_alloc(cnt + 1, GFP_KERNEL);
+ if (!run_array) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ list_add_tail(&net_link->node, &net->bpf.links[type]);
+
+ fill_prog_array(net, type, run_array);
+ run_array = rcu_replace_pointer(net->bpf.run_array[type], run_array,
+ lockdep_is_held(&netns_bpf_mutex));
+ bpf_prog_array_free(run_array);
+
+ /* Mark attach point as used */
+ netns_bpf_attach_type_need(type);
+
+out_unlock:
+ mutex_unlock(&netns_bpf_mutex);
+ return err;
+}
+
+int netns_bpf_link_create(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+ enum netns_bpf_attach_type netns_type;
+ struct bpf_link_primer link_primer;
+ struct bpf_netns_link *net_link;
+ enum bpf_attach_type type;
+ struct net *net;
+ int err;
+
+ if (attr->link_create.flags)
+ return -EINVAL;
+
+ type = attr->link_create.attach_type;
+ netns_type = to_netns_bpf_attach_type(type);
+ if (netns_type < 0)
+ return -EINVAL;
+
+ net = get_net_ns_by_fd(attr->link_create.target_fd);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ net_link = kzalloc(sizeof(*net_link), GFP_USER);
+ if (!net_link) {
+ err = -ENOMEM;
+ goto out_put_net;
+ }
+ bpf_link_init(&net_link->link, BPF_LINK_TYPE_NETNS,
+ &bpf_netns_link_ops, prog);
+ net_link->net = net;
+ net_link->type = type;
+ net_link->netns_type = netns_type;
+
+ err = bpf_link_prime(&net_link->link, &link_primer);
+ if (err) {
+ kfree(net_link);
+ goto out_put_net;
+ }
+
+ err = netns_bpf_link_attach(net, &net_link->link, netns_type);
+ if (err) {
+ bpf_link_cleanup(&link_primer);
+ goto out_put_net;
+ }
+
+ put_net(net);
+ return bpf_link_settle(&link_primer);
+
+out_put_net:
+ put_net(net);
+ return err;
+}
+
+static int __net_init netns_bpf_pernet_init(struct net *net)
+{
+ int type;
+
+ for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++)
+ INIT_LIST_HEAD(&net->bpf.links[type]);
+
+ return 0;
+}
+
+static void __net_exit netns_bpf_pernet_pre_exit(struct net *net)
+{
+ enum netns_bpf_attach_type type;
+ struct bpf_netns_link *net_link;
+
+ mutex_lock(&netns_bpf_mutex);
+ for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++) {
+ netns_bpf_run_array_detach(net, type);
+ list_for_each_entry(net_link, &net->bpf.links[type], node) {
+ net_link->net = NULL; /* auto-detach link */
+ netns_bpf_attach_type_unneed(type);
+ }
+ if (net->bpf.progs[type])
+ bpf_prog_put(net->bpf.progs[type]);
+ }
+ mutex_unlock(&netns_bpf_mutex);
+}
+
+static struct pernet_operations netns_bpf_pernet_ops __net_initdata = {
+ .init = netns_bpf_pernet_init,
+ .pre_exit = netns_bpf_pernet_pre_exit,
+};
+
+static int __init netns_bpf_init(void)
+{
+ return register_pernet_subsys(&netns_bpf_pernet_ops);
+}
+
+subsys_initcall(netns_bpf_init);