2023-06-14 23:56:41

by Anjali Kulkarni

Subject: [PATCH v6 2/6] netlink: Add new netlink_release function

A new function netlink_release is added in netlink_sock to store the
protocol's release function. This is called when the socket is deleted.
This can be supplied by the protocol via the release function in
netlink_kernel_cfg. This is being added for the NETLINK_CONNECTOR
protocol, so it can free it's data when socket is deleted.

Signed-off-by: Anjali Kulkarni <[email protected]>
---
include/linux/netlink.h | 1 +
net/netlink/af_netlink.c | 6 ++++++
net/netlink/af_netlink.h | 4 ++++
3 files changed, 11 insertions(+)

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index d73cfe5b6bc2..0db4ffe6186b 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -50,6 +50,7 @@ struct netlink_kernel_cfg {
struct mutex *cb_mutex;
int (*bind)(struct net *net, int group);
void (*unbind)(struct net *net, int group);
+ void (*release) (struct sock *sk, unsigned long *groups);
};

struct sock *__netlink_kernel_create(struct net *net, int unit,
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index e75e5156e4ac..383c10c6e6e3 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -677,6 +677,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
struct netlink_sock *nlk;
int (*bind)(struct net *net, int group);
void (*unbind)(struct net *net, int group);
+ void (*release)(struct sock *sock, unsigned long *groups);
int err = 0;

sock->state = SS_UNCONNECTED;
@@ -704,6 +705,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
cb_mutex = nl_table[protocol].cb_mutex;
bind = nl_table[protocol].bind;
unbind = nl_table[protocol].unbind;
+ release = nl_table[protocol].release;
netlink_unlock_table();

if (err < 0)
@@ -719,6 +721,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
nlk->module = module;
nlk->netlink_bind = bind;
nlk->netlink_unbind = unbind;
+ nlk->netlink_release = release;
out:
return err;

@@ -763,6 +766,8 @@ static int netlink_release(struct socket *sock)
* OK. Socket is unlinked, any packets that arrive now
* will be purged.
*/
+ if (nlk->netlink_release)
+ nlk->netlink_release(sk, nlk->groups);

/* must not acquire netlink_table_lock in any way again before unbind
* and notifying genetlink is done as otherwise it might deadlock
@@ -2091,6 +2096,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
if (cfg) {
nl_table[unit].bind = cfg->bind;
nl_table[unit].unbind = cfg->unbind;
+ nl_table[unit].release = cfg->release;
nl_table[unit].flags = cfg->flags;
}
nl_table[unit].registered = 1;
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index 90a3198a9b7f..cb2688aa347a 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h
@@ -42,6 +42,8 @@ struct netlink_sock {
void (*netlink_rcv)(struct sk_buff *skb);
int (*netlink_bind)(struct net *net, int group);
void (*netlink_unbind)(struct net *net, int group);
+ void (*netlink_release)(struct sock *sk,
+ unsigned long *groups);
struct module *module;

struct rhash_head node;
@@ -64,6 +66,8 @@ struct netlink_table {
struct module *module;
int (*bind)(struct net *net, int group);
void (*unbind)(struct net *net, int group);
+ void (*release)(struct sock *sk,
+ unsigned long *groups);
int registered;
};

--
2.41.0

2023-06-30 20:55:53

by Anjali Kulkarni

Subject: Re: [PATCH v6 2/6] netlink: Add new netlink_release function

> On Jun 30, 2023, at 1:23 PM, Liam Howlett <[email protected]> wrote:
>
> * Anjali Kulkarni <[email protected]> [230614 19:41]:
>> A new function netlink_release is added in netlink_sock to store the
>> protocol's release function. This is called when the socket is deleted.
>> This can be supplied by the protocol via the release function in
>> netlink_kernel_cfg. This is being added for the NETLINK_CONNECTOR
>> protocol, so it can free it's data when socket is deleted.
>>
>> Signed-off-by: Anjali Kulkarni <[email protected]>
>> ---
>> include/linux/netlink.h | 1 +
>> net/netlink/af_netlink.c | 6 ++++++
>> net/netlink/af_netlink.h | 4 ++++
>> 3 files changed, 11 insertions(+)
>>
>> diff --git a/include/linux/netlink.h b/include/linux/netlink.h
>> index d73cfe5b6bc2..0db4ffe6186b 100644
>> --- a/include/linux/netlink.h
>> +++ b/include/linux/netlink.h
>> @@ -50,6 +50,7 @@ struct netlink_kernel_cfg {
>> struct mutex *cb_mutex;
>> int (*bind)(struct net *net, int group);
>> void (*unbind)(struct net *net, int group);
>> + void (*release) (struct sock *sk, unsigned long *groups);
>> };
>>
>> struct sock *__netlink_kernel_create(struct net *net, int unit,
>> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
>> index e75e5156e4ac..383c10c6e6e3 100644
>> --- a/net/netlink/af_netlink.c
>> +++ b/net/netlink/af_netlink.c
>> @@ -677,6 +677,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
>> struct netlink_sock *nlk;
>> int (*bind)(struct net *net, int group);
>> void (*unbind)(struct net *net, int group);
>> + void (*release)(struct sock *sock, unsigned long *groups);
>> int err = 0;
>>
>> sock->state = SS_UNCONNECTED;
>> @@ -704,6 +705,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
>> cb_mutex = nl_table[protocol].cb_mutex;
>> bind = nl_table[protocol].bind;
>> unbind = nl_table[protocol].unbind;
>> + release = nl_table[protocol].release;
>> netlink_unlock_table();
>>
>> if (err < 0)
>> @@ -719,6 +721,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
>> nlk->module = module;
>> nlk->netlink_bind = bind;
>> nlk->netlink_unbind = unbind;
>> + nlk->netlink_release = release;
>> out:
>> return err;
>>
>> @@ -763,6 +766,8 @@ static int netlink_release(struct socket *sock)
>> * OK. Socket is unlinked, any packets that arrive now
>> * will be purged.
>> */
>> + if (nlk->netlink_release)
>> + nlk->netlink_release(sk, nlk->groups);
>>
>> /* must not acquire netlink_table_lock in any way again before unbind
>> * and notifying genetlink is done as otherwise it might deadlock
>> @@ -2091,6 +2096,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
>> if (cfg) {
>> nl_table[unit].bind = cfg->bind;
>> nl_table[unit].unbind = cfg->unbind;
>> + nl_table[unit].release = cfg->release;
>> nl_table[unit].flags = cfg->flags;
>> }
>> nl_table[unit].registered = 1;
>> diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
>> index 90a3198a9b7f..cb2688aa347a 100644
>> --- a/net/netlink/af_netlink.h
>> +++ b/net/netlink/af_netlink.h
>> @@ -42,6 +42,8 @@ struct netlink_sock {
>> void (*netlink_rcv)(struct sk_buff *skb);
>> int (*netlink_bind)(struct net *net, int group);
>> void (*netlink_unbind)(struct net *net, int group);
>> + void (*netlink_release)(struct sock *sk,
>> + unsigned long *groups);
>> struct module *module;
>>
>> struct rhash_head node;
>> @@ -64,6 +66,8 @@ struct netlink_table {
>> struct module *module;
>> int (*bind)(struct net *net, int group);
>> void (*unbind)(struct net *net, int group);
>> + void (*release)(struct sock *sk,
>
> The line above ends in a space.
>

Thanks, will fix in v7.

>> + unsigned long *groups);
>> int registered;
>> };
>>
>> --
>> 2.41.0

2023-06-30 20:59:53

by Liam R. Howlett

Subject: Re: [PATCH v6 2/6] netlink: Add new netlink_release function

* Anjali Kulkarni <[email protected]> [230614 19:41]:
> A new function netlink_release is added in netlink_sock to store the
> protocol's release function. This is called when the socket is deleted.
> This can be supplied by the protocol via the release function in
> netlink_kernel_cfg. This is being added for the NETLINK_CONNECTOR
> protocol, so it can free it's data when socket is deleted.
>
> Signed-off-by: Anjali Kulkarni <[email protected]>
> ---
> include/linux/netlink.h | 1 +
> net/netlink/af_netlink.c | 6 ++++++
> net/netlink/af_netlink.h | 4 ++++
> 3 files changed, 11 insertions(+)
>
> diff --git a/include/linux/netlink.h b/include/linux/netlink.h
> index d73cfe5b6bc2..0db4ffe6186b 100644
> --- a/include/linux/netlink.h
> +++ b/include/linux/netlink.h
> @@ -50,6 +50,7 @@ struct netlink_kernel_cfg {
> struct mutex *cb_mutex;
> int (*bind)(struct net *net, int group);
> void (*unbind)(struct net *net, int group);
> + void (*release) (struct sock *sk, unsigned long *groups);
> };
>
> struct sock *__netlink_kernel_create(struct net *net, int unit,
> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
> index e75e5156e4ac..383c10c6e6e3 100644
> --- a/net/netlink/af_netlink.c
> +++ b/net/netlink/af_netlink.c
> @@ -677,6 +677,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
> struct netlink_sock *nlk;
> int (*bind)(struct net *net, int group);
> void (*unbind)(struct net *net, int group);
> + void (*release)(struct sock *sock, unsigned long *groups);
> int err = 0;
>
> sock->state = SS_UNCONNECTED;
> @@ -704,6 +705,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
> cb_mutex = nl_table[protocol].cb_mutex;
> bind = nl_table[protocol].bind;
> unbind = nl_table[protocol].unbind;
> + release = nl_table[protocol].release;
> netlink_unlock_table();
>
> if (err < 0)
> @@ -719,6 +721,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
> nlk->module = module;
> nlk->netlink_bind = bind;
> nlk->netlink_unbind = unbind;
> + nlk->netlink_release = release;
> out:
> return err;
>
> @@ -763,6 +766,8 @@ static int netlink_release(struct socket *sock)
> * OK. Socket is unlinked, any packets that arrive now
> * will be purged.
> */
> + if (nlk->netlink_release)
> + nlk->netlink_release(sk, nlk->groups);
>
> /* must not acquire netlink_table_lock in any way again before unbind
> * and notifying genetlink is done as otherwise it might deadlock
> @@ -2091,6 +2096,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
> if (cfg) {
> nl_table[unit].bind = cfg->bind;
> nl_table[unit].unbind = cfg->unbind;
> + nl_table[unit].release = cfg->release;
> nl_table[unit].flags = cfg->flags;
> }
> nl_table[unit].registered = 1;
> diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
> index 90a3198a9b7f..cb2688aa347a 100644
> --- a/net/netlink/af_netlink.h
> +++ b/net/netlink/af_netlink.h
> @@ -42,6 +42,8 @@ struct netlink_sock {
> void (*netlink_rcv)(struct sk_buff *skb);
> int (*netlink_bind)(struct net *net, int group);
> void (*netlink_unbind)(struct net *net, int group);
> + void (*netlink_release)(struct sock *sk,
> + unsigned long *groups);
> struct module *module;
>
> struct rhash_head node;
> @@ -64,6 +66,8 @@ struct netlink_table {
> struct module *module;
> int (*bind)(struct net *net, int group);
> void (*unbind)(struct net *net, int group);
> + void (*release)(struct sock *sk,

The line above ends in a space.

> + unsigned long *groups);
> int registered;
> };
>
> --
> 2.41.0
>