[net-next,v2,06/12] net: mroute: Check if rule is a default rule

From: Yotam Gigi <yotamg@mellanox.com>

When the ipmr starts, it adds one default FIB rule that matches all packets
and sends them to the DEFAULT (multicast) FIB table. A more complex rule
can be added by user to specify that for a specific interface, a packet
should be look up at either an arbitrary table or according to the l3mdev
of the interface.

For drivers willing to offload the ipmr logic into a hardware but don't
want to offload all the FIB rules functionality, provide a function that
can indicate whether the FIB rule is the default multicast rule, thus only
one routing table is needed.

This way, a driver can register to the FIB notification chain, get
notifications about FIB rules added and trigger some kind of an internal
abort mechanism when a non default rule is added by the user.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 include/linux/mroute.h |  7 +++++++
 net/ipv4/ipmr.c        | 10 ++++++++++
 2 files changed, 17 insertions(+)

Hi, Jiri

On 2017/9/25 1:22, Jiri Pirko wrote:
> From: Yotam Gigi <yotamg@mellanox.com>
> 
> When the ipmr starts, it adds one default FIB rule that matches all packets
> and sends them to the DEFAULT (multicast) FIB table. A more complex rule
> can be added by user to specify that for a specific interface, a packet
> should be look up at either an arbitrary table or according to the l3mdev
> of the interface.
> 
> For drivers willing to offload the ipmr logic into a hardware but don't
> want to offload all the FIB rules functionality, provide a function that
> can indicate whether the FIB rule is the default multicast rule, thus only
> one routing table is needed.
> 
> This way, a driver can register to the FIB notification chain, get
> notifications about FIB rules added and trigger some kind of an internal
> abort mechanism when a non default rule is added by the user.
> 
> Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
> ---
>  include/linux/mroute.h |  7 +++++++
>  net/ipv4/ipmr.c        | 10 ++++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/include/linux/mroute.h b/include/linux/mroute.h
> index 5566580..b072a84 100644
> --- a/include/linux/mroute.h
> +++ b/include/linux/mroute.h
> @@ -5,6 +5,7 @@
>  #include <linux/pim.h>
>  #include <linux/rhashtable.h>
>  #include <net/sock.h>
> +#include <net/fib_rules.h>
>  #include <net/fib_notifier.h>
>  #include <uapi/linux/mroute.h>
>  
> @@ -19,6 +20,7 @@ int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
>  int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
>  int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
>  int ip_mr_init(void);
> +bool ipmr_rule_default(const struct fib_rule *rule);
>  #else
>  static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
>  				       char __user *optval, unsigned int optlen)
> @@ -46,6 +48,11 @@ static inline int ip_mroute_opt(int opt)
>  {
>  	return 0;
>  }
> +
> +static inline bool ipmr_rule_default(const struct fib_rule *rule)
> +{
> +	return true;
> +}
>  #endif
>  
>  struct vif_device {
> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
> index 2a795d2..a714f55 100644
> --- a/net/ipv4/ipmr.c
> +++ b/net/ipv4/ipmr.c
> @@ -320,6 +320,16 @@ static unsigned int ipmr_rules_seq_read(struct net *net)
>  }
>  #endif
>  
> +bool ipmr_rule_default(const struct fib_rule *rule)
> +{
> +#if IS_ENABLED(CONFIG_FIB_RULES)
> +	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
> +#else
> +	return true;
> +#endif

In patch 02, You have the following, can you do the same for the above?
+#ifdef CONFIG_IP_MROUTE
+void ipmr_cache_free(struct mfc_cache *mfc_cache);
+#else
+static inline void ipmr_cache_free(struct mfc_cache *mfc_cache)
+{
+}
+#endif

> +}
> +EXPORT_SYMBOL(ipmr_rule_default);
> +
>  static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
>  				const void *ptr)
>  {
>

On 09/25/2017 04:28 AM, Yunsheng Lin wrote:
> Hi, Jiri
>
> On 2017/9/25 1:22, Jiri Pirko wrote:
>> From: Yotam Gigi <yotamg@mellanox.com>
>>
>> When the ipmr starts, it adds one default FIB rule that matches all packets
>> and sends them to the DEFAULT (multicast) FIB table. A more complex rule
>> can be added by user to specify that for a specific interface, a packet
>> should be look up at either an arbitrary table or according to the l3mdev
>> of the interface.
>>
>> For drivers willing to offload the ipmr logic into a hardware but don't
>> want to offload all the FIB rules functionality, provide a function that
>> can indicate whether the FIB rule is the default multicast rule, thus only
>> one routing table is needed.
>>
>> This way, a driver can register to the FIB notification chain, get
>> notifications about FIB rules added and trigger some kind of an internal
>> abort mechanism when a non default rule is added by the user.
>>
>> Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
>> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>> ---
>>  include/linux/mroute.h |  7 +++++++
>>  net/ipv4/ipmr.c        | 10 ++++++++++
>>  2 files changed, 17 insertions(+)
>>
>> diff --git a/include/linux/mroute.h b/include/linux/mroute.h
>> index 5566580..b072a84 100644
>> --- a/include/linux/mroute.h
>> +++ b/include/linux/mroute.h
>> @@ -5,6 +5,7 @@
>>  #include <linux/pim.h>
>>  #include <linux/rhashtable.h>
>>  #include <net/sock.h>
>> +#include <net/fib_rules.h>
>>  #include <net/fib_notifier.h>
>>  #include <uapi/linux/mroute.h>
>>  
>> @@ -19,6 +20,7 @@ int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
>>  int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
>>  int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
>>  int ip_mr_init(void);
>> +bool ipmr_rule_default(const struct fib_rule *rule);
>>  #else
>>  static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
>>  				       char __user *optval, unsigned int optlen)
>> @@ -46,6 +48,11 @@ static inline int ip_mroute_opt(int opt)
>>  {
>>  	return 0;
>>  }
>> +
>> +static inline bool ipmr_rule_default(const struct fib_rule *rule)
>> +{
>> +	return true;
>> +}
>>  #endif
>>  
>>  struct vif_device {
>> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
>> index 2a795d2..a714f55 100644
>> --- a/net/ipv4/ipmr.c
>> +++ b/net/ipv4/ipmr.c
>> @@ -320,6 +320,16 @@ static unsigned int ipmr_rules_seq_read(struct net *net)
>>  }
>>  #endif
>>  
>> +bool ipmr_rule_default(const struct fib_rule *rule)
>> +{
>> +#if IS_ENABLED(CONFIG_FIB_RULES)
>> +	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
>> +#else
>> +	return true;
>> +#endif
> In patch 02, You have the following, can you do the same for the above?
> +#ifdef CONFIG_IP_MROUTE
> +void ipmr_cache_free(struct mfc_cache *mfc_cache);
> +#else
> +static inline void ipmr_cache_free(struct mfc_cache *mfc_cache)
> +{
> +}
> +#endif

OK.

>> +}
>> +EXPORT_SYMBOL(ipmr_rule_default);
>> +
>>  static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
>>  				const void *ptr)
>>  {
>>

On 24/09/17 20:22, Jiri Pirko wrote:
> From: Yotam Gigi <yotamg@mellanox.com>
> 
> When the ipmr starts, it adds one default FIB rule that matches all packets
> and sends them to the DEFAULT (multicast) FIB table. A more complex rule
> can be added by user to specify that for a specific interface, a packet
> should be look up at either an arbitrary table or according to the l3mdev
> of the interface.
> 
> For drivers willing to offload the ipmr logic into a hardware but don't
> want to offload all the FIB rules functionality, provide a function that
> can indicate whether the FIB rule is the default multicast rule, thus only
> one routing table is needed.
> 
> This way, a driver can register to the FIB notification chain, get
> notifications about FIB rules added and trigger some kind of an internal
> abort mechanism when a non default rule is added by the user.
> 
> Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
> ---
>  include/linux/mroute.h |  7 +++++++
>  net/ipv4/ipmr.c        | 10 ++++++++++
>  2 files changed, 17 insertions(+)
> 

I saw the comment and am fine with the patch either way, so you can
add my:

Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

Thanks

Mon, Sep 25, 2017 at 03:28:21AM CEST, linyunsheng@huawei.com wrote:
>Hi, Jiri
>
>On 2017/9/25 1:22, Jiri Pirko wrote:
>> From: Yotam Gigi <yotamg@mellanox.com>
>> 
>> When the ipmr starts, it adds one default FIB rule that matches all packets
>> and sends them to the DEFAULT (multicast) FIB table. A more complex rule
>> can be added by user to specify that for a specific interface, a packet
>> should be look up at either an arbitrary table or according to the l3mdev
>> of the interface.
>> 
>> For drivers willing to offload the ipmr logic into a hardware but don't
>> want to offload all the FIB rules functionality, provide a function that
>> can indicate whether the FIB rule is the default multicast rule, thus only
>> one routing table is needed.
>> 
>> This way, a driver can register to the FIB notification chain, get
>> notifications about FIB rules added and trigger some kind of an internal
>> abort mechanism when a non default rule is added by the user.
>> 
>> Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
>> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>> ---
>>  include/linux/mroute.h |  7 +++++++
>>  net/ipv4/ipmr.c        | 10 ++++++++++
>>  2 files changed, 17 insertions(+)
>> 
>> diff --git a/include/linux/mroute.h b/include/linux/mroute.h
>> index 5566580..b072a84 100644
>> --- a/include/linux/mroute.h
>> +++ b/include/linux/mroute.h
>> @@ -5,6 +5,7 @@
>>  #include <linux/pim.h>
>>  #include <linux/rhashtable.h>
>>  #include <net/sock.h>
>> +#include <net/fib_rules.h>
>>  #include <net/fib_notifier.h>
>>  #include <uapi/linux/mroute.h>
>>  
>> @@ -19,6 +20,7 @@ int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
>>  int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
>>  int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
>>  int ip_mr_init(void);
>> +bool ipmr_rule_default(const struct fib_rule *rule);
>>  #else
>>  static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
>>  				       char __user *optval, unsigned int optlen)
>> @@ -46,6 +48,11 @@ static inline int ip_mroute_opt(int opt)
>>  {
>>  	return 0;
>>  }
>> +
>> +static inline bool ipmr_rule_default(const struct fib_rule *rule)
>> +{
>> +	return true;
>> +}
>>  #endif
>>  
>>  struct vif_device {
>> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
>> index 2a795d2..a714f55 100644
>> --- a/net/ipv4/ipmr.c
>> +++ b/net/ipv4/ipmr.c
>> @@ -320,6 +320,16 @@ static unsigned int ipmr_rules_seq_read(struct net *net)
>>  }
>>  #endif
>>  
>> +bool ipmr_rule_default(const struct fib_rule *rule)
>> +{
>> +#if IS_ENABLED(CONFIG_FIB_RULES)
>> +	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
>> +#else
>> +	return true;
>> +#endif
>
>In patch 02, You have the following, can you do the same for the above?
>+#ifdef CONFIG_IP_MROUTE
>+void ipmr_cache_free(struct mfc_cache *mfc_cache);
>+#else
>+static inline void ipmr_cache_free(struct mfc_cache *mfc_cache)
>+{
>+}
>+#endif

I don't believe this is necessary. The solution you described is often
used in headers. But here, I'm ok with the current code.


>
>> +}
>> +EXPORT_SYMBOL(ipmr_rule_default);
>> +
>>  static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
>>  				const void *ptr)
>>  {
>> 
>

On 25/09/17 12:45, Jiri Pirko wrote:
> Mon, Sep 25, 2017 at 03:28:21AM CEST, linyunsheng@huawei.com wrote:
>> Hi, Jiri
>>
>> On 2017/9/25 1:22, Jiri Pirko wrote:
>>> From: Yotam Gigi <yotamg@mellanox.com>
>>>
>>> When the ipmr starts, it adds one default FIB rule that matches all packets
>>> and sends them to the DEFAULT (multicast) FIB table. A more complex rule
>>> can be added by user to specify that for a specific interface, a packet
>>> should be look up at either an arbitrary table or according to the l3mdev
>>> of the interface.
>>>
>>> For drivers willing to offload the ipmr logic into a hardware but don't
>>> want to offload all the FIB rules functionality, provide a function that
>>> can indicate whether the FIB rule is the default multicast rule, thus only
>>> one routing table is needed.
>>>
>>> This way, a driver can register to the FIB notification chain, get
>>> notifications about FIB rules added and trigger some kind of an internal
>>> abort mechanism when a non default rule is added by the user.
>>>
>>> Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
>>> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
>>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>>> ---
>>>  include/linux/mroute.h |  7 +++++++
>>>  net/ipv4/ipmr.c        | 10 ++++++++++
>>>  2 files changed, 17 insertions(+)
>>>
>>> diff --git a/include/linux/mroute.h b/include/linux/mroute.h
>>> index 5566580..b072a84 100644
>>> --- a/include/linux/mroute.h
>>> +++ b/include/linux/mroute.h
>>> @@ -5,6 +5,7 @@
>>>  #include <linux/pim.h>
>>>  #include <linux/rhashtable.h>
>>>  #include <net/sock.h>
>>> +#include <net/fib_rules.h>
>>>  #include <net/fib_notifier.h>
>>>  #include <uapi/linux/mroute.h>
>>>  
>>> @@ -19,6 +20,7 @@ int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
>>>  int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
>>>  int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
>>>  int ip_mr_init(void);
>>> +bool ipmr_rule_default(const struct fib_rule *rule);
>>>  #else
>>>  static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
>>>  				       char __user *optval, unsigned int optlen)
>>> @@ -46,6 +48,11 @@ static inline int ip_mroute_opt(int opt)
>>>  {
>>>  	return 0;
>>>  }
>>> +
>>> +static inline bool ipmr_rule_default(const struct fib_rule *rule)
>>> +{
>>> +	return true;
>>> +}
>>>  #endif
>>>  
>>>  struct vif_device {
>>> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
>>> index 2a795d2..a714f55 100644
>>> --- a/net/ipv4/ipmr.c
>>> +++ b/net/ipv4/ipmr.c
>>> @@ -320,6 +320,16 @@ static unsigned int ipmr_rules_seq_read(struct net *net)
>>>  }
>>>  #endif
>>>  
>>> +bool ipmr_rule_default(const struct fib_rule *rule)
>>> +{
>>> +#if IS_ENABLED(CONFIG_FIB_RULES)
>>> +	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
>>> +#else
>>> +	return true;
>>> +#endif
>>
>> In patch 02, You have the following, can you do the same for the above?
>> +#ifdef CONFIG_IP_MROUTE
>> +void ipmr_cache_free(struct mfc_cache *mfc_cache);
>> +#else
>> +static inline void ipmr_cache_free(struct mfc_cache *mfc_cache)
>> +{
>> +}
>> +#endif
> 
> I don't believe this is necessary. The solution you described is often
> used in headers. But here, I'm ok with the current code.
> 

+1

> 
>>
>>> +}
>>> +EXPORT_SYMBOL(ipmr_rule_default);
>>> +
>>>  static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
>>>  				const void *ptr)
>>>  {
>>>
>>

On 09/25/2017 01:02 PM, Nikolay Aleksandrov wrote:
> On 25/09/17 12:45, Jiri Pirko wrote:
>> Mon, Sep 25, 2017 at 03:28:21AM CEST, linyunsheng@huawei.com wrote:
>>> Hi, Jiri
>>>
>>> On 2017/9/25 1:22, Jiri Pirko wrote:
>>>> From: Yotam Gigi <yotamg@mellanox.com>
>>>>
>>>> When the ipmr starts, it adds one default FIB rule that matches all packets
>>>> and sends them to the DEFAULT (multicast) FIB table. A more complex rule
>>>> can be added by user to specify that for a specific interface, a packet
>>>> should be look up at either an arbitrary table or according to the l3mdev
>>>> of the interface.
>>>>
>>>> For drivers willing to offload the ipmr logic into a hardware but don't
>>>> want to offload all the FIB rules functionality, provide a function that
>>>> can indicate whether the FIB rule is the default multicast rule, thus only
>>>> one routing table is needed.
>>>>
>>>> This way, a driver can register to the FIB notification chain, get
>>>> notifications about FIB rules added and trigger some kind of an internal
>>>> abort mechanism when a non default rule is added by the user.
>>>>
>>>> Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
>>>> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
>>>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>>>> ---
>>>>  include/linux/mroute.h |  7 +++++++
>>>>  net/ipv4/ipmr.c        | 10 ++++++++++
>>>>  2 files changed, 17 insertions(+)
>>>>
>>>> diff --git a/include/linux/mroute.h b/include/linux/mroute.h
>>>> index 5566580..b072a84 100644
>>>> --- a/include/linux/mroute.h
>>>> +++ b/include/linux/mroute.h
>>>> @@ -5,6 +5,7 @@
>>>>  #include <linux/pim.h>
>>>>  #include <linux/rhashtable.h>
>>>>  #include <net/sock.h>
>>>> +#include <net/fib_rules.h>
>>>>  #include <net/fib_notifier.h>
>>>>  #include <uapi/linux/mroute.h>
>>>>  
>>>> @@ -19,6 +20,7 @@ int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
>>>>  int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
>>>>  int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
>>>>  int ip_mr_init(void);
>>>> +bool ipmr_rule_default(const struct fib_rule *rule);
>>>>  #else
>>>>  static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
>>>>  				       char __user *optval, unsigned int optlen)
>>>> @@ -46,6 +48,11 @@ static inline int ip_mroute_opt(int opt)
>>>>  {
>>>>  	return 0;
>>>>  }
>>>> +
>>>> +static inline bool ipmr_rule_default(const struct fib_rule *rule)
>>>> +{
>>>> +	return true;
>>>> +}
>>>>  #endif
>>>>  
>>>>  struct vif_device {
>>>> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
>>>> index 2a795d2..a714f55 100644
>>>> --- a/net/ipv4/ipmr.c
>>>> +++ b/net/ipv4/ipmr.c
>>>> @@ -320,6 +320,16 @@ static unsigned int ipmr_rules_seq_read(struct net *net)
>>>>  }
>>>>  #endif
>>>>  
>>>> +bool ipmr_rule_default(const struct fib_rule *rule)
>>>> +{
>>>> +#if IS_ENABLED(CONFIG_FIB_RULES)
>>>> +	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
>>>> +#else
>>>> +	return true;
>>>> +#endif
>>> In patch 02, You have the following, can you do the same for the above?
>>> +#ifdef CONFIG_IP_MROUTE
>>> +void ipmr_cache_free(struct mfc_cache *mfc_cache);
>>> +#else
>>> +static inline void ipmr_cache_free(struct mfc_cache *mfc_cache)
>>> +{
>>> +}
>>> +#endif
>> I don't believe this is necessary. The solution you described is often
>> used in headers. But here, I'm ok with the current code.
>>
> +1


Hmm, when re-looking at it, I think I will just use the already existing
#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES other than adding a new one. It selects
the CONFIG_FIB_RULES, and if CONFIG_IP_MROUTE_MULTIPLE_TABLES is not defined
than only default rules can exist for the IPMR family.

I will fix it for v3.



>
>>>> +}
>>>> +EXPORT_SYMBOL(ipmr_rule_default);
>>>> +
>>>>  static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
>>>>  				const void *ptr)
>>>>  {
>>>>