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linux/net/ipv4/tcp_ulp.c

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tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
/*
* Pluggable TCP upper layer protocol support.
*
* Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
* Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
*
*/
#include<linux/module.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/gfp.h>
#include <net/tcp.h>
static DEFINE_SPINLOCK(tcp_ulp_list_lock);
static LIST_HEAD(tcp_ulp_list);
/* Simple linear search, don't expect many entries! */
static struct tcp_ulp_ops *tcp_ulp_find(const char *name)
{
struct tcp_ulp_ops *e;
list_for_each_entry_rcu(e, &tcp_ulp_list, list) {
if (strcmp(e->name, name) == 0)
return e;
}
return NULL;
}
net: add a UID to use for ULP socket assignment Create a UID field and enum that can be used to assign ULPs to sockets. This saves a set of string comparisons if the ULP id is known. For sockmap, which is added in the next patches, a ULP is used to hook into TCP sockets close state. In this case the ULP being added is done at map insert time and the ULP is known and done on the kernel side. In this case the named lookup is not needed. Because we don't want to expose psock internals to user space socket options a user visible flag is also added. For TLS this is set for BPF it will be cleared. Alos remove pr_notice, user gets an error code back and should check that rather than rely on logs. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-05 18:17:43 +00:00
static struct tcp_ulp_ops *tcp_ulp_find_id(const int ulp)
{
struct tcp_ulp_ops *e;
list_for_each_entry_rcu(e, &tcp_ulp_list, list) {
if (e->uid == ulp)
return e;
}
return NULL;
}
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name)
{
const struct tcp_ulp_ops *ulp = NULL;
rcu_read_lock();
ulp = tcp_ulp_find(name);
#ifdef CONFIG_MODULES
if (!ulp && capable(CAP_NET_ADMIN)) {
rcu_read_unlock();
tcp, ulp: add alias for all ulp modules Lets not turn the TCP ULP lookup into an arbitrary module loader as we only intend to load ULP modules through this mechanism, not other unrelated kernel modules: [root@bar]# cat foo.c #include <sys/types.h> #include <sys/socket.h> #include <linux/tcp.h> #include <linux/in.h> int main(void) { int sock = socket(PF_INET, SOCK_STREAM, 0); setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp")); return 0; } [root@bar]# gcc foo.c -O2 -Wall [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp sctp 1077248 4 libcrc32c 16384 3 nf_conntrack,nf_nat,sctp [root@bar]# Fix it by adding module alias to TCP ULP modules, so probing module via request_module() will be limited to tcp-ulp-[name]. The existing modules like kTLS will load fine given tcp-ulp-tls alias, but others will fail to load: [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp [root@bar]# Sockmap is not affected from this since it's either built-in or not. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-16 19:49:06 +00:00
request_module("tcp-ulp-%s", name);
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
rcu_read_lock();
ulp = tcp_ulp_find(name);
}
#endif
if (!ulp || !try_module_get(ulp->owner))
ulp = NULL;
rcu_read_unlock();
return ulp;
}
net: add a UID to use for ULP socket assignment Create a UID field and enum that can be used to assign ULPs to sockets. This saves a set of string comparisons if the ULP id is known. For sockmap, which is added in the next patches, a ULP is used to hook into TCP sockets close state. In this case the ULP being added is done at map insert time and the ULP is known and done on the kernel side. In this case the named lookup is not needed. Because we don't want to expose psock internals to user space socket options a user visible flag is also added. For TLS this is set for BPF it will be cleared. Alos remove pr_notice, user gets an error code back and should check that rather than rely on logs. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-05 18:17:43 +00:00
static const struct tcp_ulp_ops *__tcp_ulp_lookup(const int uid)
{
const struct tcp_ulp_ops *ulp;
rcu_read_lock();
ulp = tcp_ulp_find_id(uid);
if (!ulp || !try_module_get(ulp->owner))
ulp = NULL;
rcu_read_unlock();
return ulp;
}
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
/* Attach new upper layer protocol to the list
* of available protocols.
*/
int tcp_register_ulp(struct tcp_ulp_ops *ulp)
{
int ret = 0;
spin_lock(&tcp_ulp_list_lock);
net: add a UID to use for ULP socket assignment Create a UID field and enum that can be used to assign ULPs to sockets. This saves a set of string comparisons if the ULP id is known. For sockmap, which is added in the next patches, a ULP is used to hook into TCP sockets close state. In this case the ULP being added is done at map insert time and the ULP is known and done on the kernel side. In this case the named lookup is not needed. Because we don't want to expose psock internals to user space socket options a user visible flag is also added. For TLS this is set for BPF it will be cleared. Alos remove pr_notice, user gets an error code back and should check that rather than rely on logs. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-05 18:17:43 +00:00
if (tcp_ulp_find(ulp->name))
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
ret = -EEXIST;
net: add a UID to use for ULP socket assignment Create a UID field and enum that can be used to assign ULPs to sockets. This saves a set of string comparisons if the ULP id is known. For sockmap, which is added in the next patches, a ULP is used to hook into TCP sockets close state. In this case the ULP being added is done at map insert time and the ULP is known and done on the kernel side. In this case the named lookup is not needed. Because we don't want to expose psock internals to user space socket options a user visible flag is also added. For TLS this is set for BPF it will be cleared. Alos remove pr_notice, user gets an error code back and should check that rather than rely on logs. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-05 18:17:43 +00:00
else
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
list_add_tail_rcu(&ulp->list, &tcp_ulp_list);
spin_unlock(&tcp_ulp_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(tcp_register_ulp);
void tcp_unregister_ulp(struct tcp_ulp_ops *ulp)
{
spin_lock(&tcp_ulp_list_lock);
list_del_rcu(&ulp->list);
spin_unlock(&tcp_ulp_list_lock);
synchronize_rcu();
}
EXPORT_SYMBOL_GPL(tcp_unregister_ulp);
/* Build string with list of available upper layer protocl values */
void tcp_get_available_ulp(char *buf, size_t maxlen)
{
struct tcp_ulp_ops *ulp_ops;
size_t offs = 0;
tcp: fix out-of-bounds access in ULP sysctl KASAN reports out-of-bound access in proc_dostring() coming from proc_tcp_available_ulp() because in case TCP ULP list is empty the buffer allocated for the response will not have anything printed into it. Set the first byte to zero to avoid strlen() going out-of-bounds. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23 01:57:55 +00:00
*buf = '\0';
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
rcu_read_lock();
list_for_each_entry_rcu(ulp_ops, &tcp_ulp_list, list) {
offs += snprintf(buf + offs, maxlen - offs,
"%s%s",
offs == 0 ? "" : " ", ulp_ops->name);
}
rcu_read_unlock();
}
void tcp_cleanup_ulp(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
if (!icsk->icsk_ulp_ops)
return;
if (icsk->icsk_ulp_ops->release)
icsk->icsk_ulp_ops->release(sk);
module_put(icsk->icsk_ulp_ops->owner);
tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattach I found that in BPF sockmap programs once we either delete a socket from the map or we updated a map slot and the old socket was purged from the map that these socket can never get reattached into a map even though their related psock has been dropped entirely at that point. Reason is that tcp_cleanup_ulp() leaves the old icsk->icsk_ulp_ops intact, so that on the next tcp_set_ulp_id() the kernel returns an -EEXIST thinking there is still some active ULP attached. BPF sockmap is the only one that has this issue as the other user, kTLS, only calls tcp_cleanup_ulp() from tcp_v4_destroy_sock() whereas sockmap semantics allow dropping the socket from the map with all related psock state being cleaned up. Fixes: 1aa12bdf1bfb ("bpf: sockmap, add sock close() hook to remove socks") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-16 19:49:07 +00:00
icsk->icsk_ulp_ops = NULL;
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
}
/* Change upper layer protocol for socket */
int tcp_set_ulp(struct sock *sk, const char *name)
{
struct inet_connection_sock *icsk = inet_csk(sk);
const struct tcp_ulp_ops *ulp_ops;
int err = 0;
if (icsk->icsk_ulp_ops)
return -EEXIST;
ulp_ops = __tcp_ulp_find_autoload(name);
if (!ulp_ops)
tcp: ulp: avoid module refcnt leak in tcp_set_ulp __tcp_ulp_find_autoload returns tcp_ulp_ops after taking a reference on the module. Then, if ->init fails, tcp_set_ulp propagates the error but nothing releases that reference. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-14 16:04:24 +00:00
return -ENOENT;
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
net: add a UID to use for ULP socket assignment Create a UID field and enum that can be used to assign ULPs to sockets. This saves a set of string comparisons if the ULP id is known. For sockmap, which is added in the next patches, a ULP is used to hook into TCP sockets close state. In this case the ULP being added is done at map insert time and the ULP is known and done on the kernel side. In this case the named lookup is not needed. Because we don't want to expose psock internals to user space socket options a user visible flag is also added. For TLS this is set for BPF it will be cleared. Alos remove pr_notice, user gets an error code back and should check that rather than rely on logs. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-05 18:17:43 +00:00
if (!ulp_ops->user_visible) {
module_put(ulp_ops->owner);
return -ENOENT;
}
err = ulp_ops->init(sk);
if (err) {
module_put(ulp_ops->owner);
return err;
}
icsk->icsk_ulp_ops = ulp_ops;
return 0;
}
int tcp_set_ulp_id(struct sock *sk, int ulp)
{
struct inet_connection_sock *icsk = inet_csk(sk);
const struct tcp_ulp_ops *ulp_ops;
int err;
if (icsk->icsk_ulp_ops)
return -EEXIST;
ulp_ops = __tcp_ulp_lookup(ulp);
if (!ulp_ops)
return -ENOENT;
tcp: ulp: avoid module refcnt leak in tcp_set_ulp __tcp_ulp_find_autoload returns tcp_ulp_ops after taking a reference on the module. Then, if ->init fails, tcp_set_ulp propagates the error but nothing releases that reference. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-14 16:04:24 +00:00
err = ulp_ops->init(sk);
if (err) {
module_put(ulp_ops->owner);
return err;
}
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
icsk->icsk_ulp_ops = ulp_ops;
tcp: ulp: avoid module refcnt leak in tcp_set_ulp __tcp_ulp_find_autoload returns tcp_ulp_ops after taking a reference on the module. Then, if ->init fails, tcp_set_ulp propagates the error but nothing releases that reference. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-14 16:04:24 +00:00
return 0;
tcp: ULP infrastructure Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 18:37:14 +00:00
}
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