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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /net/handshake/netlink.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/handshake/netlink.c')
-rw-r--r--net/handshake/netlink.c291
1 files changed, 291 insertions, 0 deletions
diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c
new file mode 100644
index 0000000000..80c7302692
--- /dev/null
+++ b/net/handshake/netlink.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic netlink handshake service
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2023, Oracle and/or its affiliates.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/mm.h>
+
+#include <net/sock.h>
+#include <net/genetlink.h>
+#include <net/netns/generic.h>
+
+#include <kunit/visibility.h>
+
+#include <uapi/linux/handshake.h>
+#include "handshake.h"
+#include "genl.h"
+
+#include <trace/events/handshake.h>
+
+/**
+ * handshake_genl_notify - Notify handlers that a request is waiting
+ * @net: target network namespace
+ * @proto: handshake protocol
+ * @flags: memory allocation control flags
+ *
+ * Returns zero on success or a negative errno if notification failed.
+ */
+int handshake_genl_notify(struct net *net, const struct handshake_proto *proto,
+ gfp_t flags)
+{
+ struct sk_buff *msg;
+ void *hdr;
+
+ /* Disable notifications during unit testing */
+ if (!test_bit(HANDSHAKE_F_PROTO_NOTIFY, &proto->hp_flags))
+ return 0;
+
+ if (!genl_has_listeners(&handshake_nl_family, net,
+ proto->hp_handler_class))
+ return -ESRCH;
+
+ msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, flags);
+ if (!msg)
+ return -ENOMEM;
+
+ hdr = genlmsg_put(msg, 0, 0, &handshake_nl_family, 0,
+ HANDSHAKE_CMD_READY);
+ if (!hdr)
+ goto out_free;
+
+ if (nla_put_u32(msg, HANDSHAKE_A_ACCEPT_HANDLER_CLASS,
+ proto->hp_handler_class) < 0) {
+ genlmsg_cancel(msg, hdr);
+ goto out_free;
+ }
+
+ genlmsg_end(msg, hdr);
+ return genlmsg_multicast_netns(&handshake_nl_family, net, msg,
+ 0, proto->hp_handler_class, flags);
+
+out_free:
+ nlmsg_free(msg);
+ return -EMSGSIZE;
+}
+
+/**
+ * handshake_genl_put - Create a generic netlink message header
+ * @msg: buffer in which to create the header
+ * @info: generic netlink message context
+ *
+ * Returns a ready-to-use header, or NULL.
+ */
+struct nlmsghdr *handshake_genl_put(struct sk_buff *msg,
+ struct genl_info *info)
+{
+ return genlmsg_put(msg, info->snd_portid, info->snd_seq,
+ &handshake_nl_family, 0, info->genlhdr->cmd);
+}
+EXPORT_SYMBOL(handshake_genl_put);
+
+int handshake_nl_accept_doit(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net *net = sock_net(skb->sk);
+ struct handshake_net *hn = handshake_pernet(net);
+ struct handshake_req *req = NULL;
+ struct socket *sock;
+ int class, fd, err;
+
+ err = -EOPNOTSUPP;
+ if (!hn)
+ goto out_status;
+
+ err = -EINVAL;
+ if (GENL_REQ_ATTR_CHECK(info, HANDSHAKE_A_ACCEPT_HANDLER_CLASS))
+ goto out_status;
+ class = nla_get_u32(info->attrs[HANDSHAKE_A_ACCEPT_HANDLER_CLASS]);
+
+ err = -EAGAIN;
+ req = handshake_req_next(hn, class);
+ if (!req)
+ goto out_status;
+
+ sock = req->hr_sk->sk_socket;
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0) {
+ err = fd;
+ goto out_complete;
+ }
+
+ err = req->hr_proto->hp_accept(req, info, fd);
+ if (err) {
+ put_unused_fd(fd);
+ goto out_complete;
+ }
+
+ fd_install(fd, get_file(sock->file));
+
+ trace_handshake_cmd_accept(net, req, req->hr_sk, fd);
+ return 0;
+
+out_complete:
+ handshake_complete(req, -EIO, NULL);
+out_status:
+ trace_handshake_cmd_accept_err(net, req, NULL, err);
+ return err;
+}
+
+int handshake_nl_done_doit(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net *net = sock_net(skb->sk);
+ struct handshake_req *req;
+ struct socket *sock;
+ int fd, status, err;
+
+ if (GENL_REQ_ATTR_CHECK(info, HANDSHAKE_A_DONE_SOCKFD))
+ return -EINVAL;
+ fd = nla_get_u32(info->attrs[HANDSHAKE_A_DONE_SOCKFD]);
+
+ sock = sockfd_lookup(fd, &err);
+ if (!sock)
+ return err;
+
+ req = handshake_req_hash_lookup(sock->sk);
+ if (!req) {
+ err = -EBUSY;
+ trace_handshake_cmd_done_err(net, req, sock->sk, err);
+ fput(sock->file);
+ return err;
+ }
+
+ trace_handshake_cmd_done(net, req, sock->sk, fd);
+
+ status = -EIO;
+ if (info->attrs[HANDSHAKE_A_DONE_STATUS])
+ status = nla_get_u32(info->attrs[HANDSHAKE_A_DONE_STATUS]);
+
+ handshake_complete(req, status, info);
+ fput(sock->file);
+ return 0;
+}
+
+static unsigned int handshake_net_id;
+
+static int __net_init handshake_net_init(struct net *net)
+{
+ struct handshake_net *hn = net_generic(net, handshake_net_id);
+ unsigned long tmp;
+ struct sysinfo si;
+
+ /*
+ * Arbitrary limit to prevent handshakes that do not make
+ * progress from clogging up the system. The cap scales up
+ * with the amount of physical memory on the system.
+ */
+ si_meminfo(&si);
+ tmp = si.totalram / (25 * si.mem_unit);
+ hn->hn_pending_max = clamp(tmp, 3UL, 50UL);
+
+ spin_lock_init(&hn->hn_lock);
+ hn->hn_pending = 0;
+ hn->hn_flags = 0;
+ INIT_LIST_HEAD(&hn->hn_requests);
+ return 0;
+}
+
+static void __net_exit handshake_net_exit(struct net *net)
+{
+ struct handshake_net *hn = net_generic(net, handshake_net_id);
+ struct handshake_req *req;
+ LIST_HEAD(requests);
+
+ /*
+ * Drain the net's pending list. Requests that have been
+ * accepted and are in progress will be destroyed when
+ * the socket is closed.
+ */
+ spin_lock(&hn->hn_lock);
+ set_bit(HANDSHAKE_F_NET_DRAINING, &hn->hn_flags);
+ list_splice_init(&requests, &hn->hn_requests);
+ spin_unlock(&hn->hn_lock);
+
+ while (!list_empty(&requests)) {
+ req = list_first_entry(&requests, struct handshake_req, hr_list);
+ list_del(&req->hr_list);
+
+ /*
+ * Requests on this list have not yet been
+ * accepted, so they do not have an fd to put.
+ */
+
+ handshake_complete(req, -ETIMEDOUT, NULL);
+ }
+}
+
+static struct pernet_operations handshake_genl_net_ops = {
+ .init = handshake_net_init,
+ .exit = handshake_net_exit,
+ .id = &handshake_net_id,
+ .size = sizeof(struct handshake_net),
+};
+
+/**
+ * handshake_pernet - Get the handshake private per-net structure
+ * @net: network namespace
+ *
+ * Returns a pointer to the net's private per-net structure for the
+ * handshake module, or NULL if handshake_init() failed.
+ */
+struct handshake_net *handshake_pernet(struct net *net)
+{
+ return handshake_net_id ?
+ net_generic(net, handshake_net_id) : NULL;
+}
+EXPORT_SYMBOL_IF_KUNIT(handshake_pernet);
+
+static int __init handshake_init(void)
+{
+ int ret;
+
+ ret = handshake_req_hash_init();
+ if (ret) {
+ pr_warn("handshake: hash initialization failed (%d)\n", ret);
+ return ret;
+ }
+
+ ret = genl_register_family(&handshake_nl_family);
+ if (ret) {
+ pr_warn("handshake: netlink registration failed (%d)\n", ret);
+ handshake_req_hash_destroy();
+ return ret;
+ }
+
+ /*
+ * ORDER: register_pernet_subsys must be done last.
+ *
+ * If initialization does not make it past pernet_subsys
+ * registration, then handshake_net_id will remain 0. That
+ * shunts the handshake consumer API to return ENOTSUPP
+ * to prevent it from dereferencing something that hasn't
+ * been allocated.
+ */
+ ret = register_pernet_subsys(&handshake_genl_net_ops);
+ if (ret) {
+ pr_warn("handshake: pernet registration failed (%d)\n", ret);
+ genl_unregister_family(&handshake_nl_family);
+ handshake_req_hash_destroy();
+ }
+
+ return ret;
+}
+
+static void __exit handshake_exit(void)
+{
+ unregister_pernet_subsys(&handshake_genl_net_ops);
+ handshake_net_id = 0;
+
+ handshake_req_hash_destroy();
+ genl_unregister_family(&handshake_nl_family);
+}
+
+module_init(handshake_init);
+module_exit(handshake_exit);