2 * Pluggable TCP upper layer protocol support.
4 * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
5 * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
9 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/list.h>
13 #include <linux/gfp.h>
16 static DEFINE_SPINLOCK(tcp_ulp_list_lock);
17 static LIST_HEAD(tcp_ulp_list);
19 /* Simple linear search, don't expect many entries! */
20 static struct tcp_ulp_ops *tcp_ulp_find(const char *name)
22 struct tcp_ulp_ops *e;
24 list_for_each_entry_rcu(e, &tcp_ulp_list, list) {
25 if (strcmp(e->name, name) == 0)
32 static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name)
34 const struct tcp_ulp_ops *ulp = NULL;
37 ulp = tcp_ulp_find(name);
40 if (!ulp && capable(CAP_NET_ADMIN)) {
42 request_module("tcp-ulp-%s", name);
44 ulp = tcp_ulp_find(name);
47 if (!ulp || !try_module_get(ulp->owner))
54 /* Attach new upper layer protocol to the list
55 * of available protocols.
57 int tcp_register_ulp(struct tcp_ulp_ops *ulp)
61 spin_lock(&tcp_ulp_list_lock);
62 if (tcp_ulp_find(ulp->name))
65 list_add_tail_rcu(&ulp->list, &tcp_ulp_list);
66 spin_unlock(&tcp_ulp_list_lock);
70 EXPORT_SYMBOL_GPL(tcp_register_ulp);
72 void tcp_unregister_ulp(struct tcp_ulp_ops *ulp)
74 spin_lock(&tcp_ulp_list_lock);
75 list_del_rcu(&ulp->list);
76 spin_unlock(&tcp_ulp_list_lock);
80 EXPORT_SYMBOL_GPL(tcp_unregister_ulp);
82 /* Build string with list of available upper layer protocl values */
83 void tcp_get_available_ulp(char *buf, size_t maxlen)
85 struct tcp_ulp_ops *ulp_ops;
90 list_for_each_entry_rcu(ulp_ops, &tcp_ulp_list, list) {
91 offs += snprintf(buf + offs, maxlen - offs,
93 offs == 0 ? "" : " ", ulp_ops->name);
98 void tcp_cleanup_ulp(struct sock *sk)
100 struct inet_connection_sock *icsk = inet_csk(sk);
102 sock_owned_by_me(sk);
104 if (!icsk->icsk_ulp_ops)
107 if (icsk->icsk_ulp_ops->release)
108 icsk->icsk_ulp_ops->release(sk);
109 module_put(icsk->icsk_ulp_ops->owner);
111 icsk->icsk_ulp_ops = NULL;
114 static int __tcp_set_ulp(struct sock *sk, const struct tcp_ulp_ops *ulp_ops)
116 struct inet_connection_sock *icsk = inet_csk(sk);
120 if (icsk->icsk_ulp_ops)
123 err = ulp_ops->init(sk);
127 icsk->icsk_ulp_ops = ulp_ops;
130 module_put(ulp_ops->owner);
134 int tcp_set_ulp(struct sock *sk, const char *name)
136 const struct tcp_ulp_ops *ulp_ops;
138 sock_owned_by_me(sk);
140 ulp_ops = __tcp_ulp_find_autoload(name);
144 return __tcp_set_ulp(sk, ulp_ops);