On 03/21/2018 03:38 AM, Jon Maloy wrote:
> Setting network identity is currently a write-once operation, so the
> scenarios you are listing below cannot happen. I don't see any reason to ever
> change this as long as the net id is associated to the node.
> If we decide to associate it to bearers instead, as I suggested earlier, that
> may change of course.
>
Yes, you are right. We have prohibited to change net_id after node
address has been set.
tipc_nl_net_set()
{
...
if (attrs[TIPC_NLA_NET_ID]) {
u32 val;
/* Can't change net id once TIPC has joined a network */
if (tn->own_addr)
return -EPERM; --->disallow to set net_id again.
val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
if (val < 1 || val > 9999)
return -EINVAL;
tn->net_id = val;
}
...
}
But probably, it's necessary to dynamically adjust it in the future.
> BR
> ///jon
>
>> -----Original Message-----
>> From: Ying Xue [mailto:[email protected]]
>> Sent: Tuesday, March 20, 2018 09:53
>> To: Jon Maloy <[email protected]>; Jon Maloy
>> <[email protected]>
>> Cc: Mohan Krishna Ghanta Krishnamurthy
>> <[email protected]>; Tung Quang Nguyen
>> <[email protected]>; Hoang Huu Le
>> <[email protected]>; Canh Duc Luu
>> <[email protected]>; [email protected]; tipc-
>> [email protected]
>> Subject: Re: [net-next v2 8/8] tipc: obtain node identity from interface by
>> default
>>
>> On 03/19/2018 08:10 PM, Jon Maloy wrote:
>>> Selecting and expicitly configuring a TIPC node identity may be
>>> unwanted
>>
>> s/expicitly/explicitly
>>
>>> in some cases.
>>>
>>> In this commit we introduce a default setting if the identity has not
>>> been set at the moment the first bearer is enabled. We do this by
>>> using a raw copy of a unique identifier from the used interface: MAC
>>> address in the case of an L2 bearer, IPv4/IPv6 address in the case of
>>> a UDP bearer.
>>>
>>
>> This is a good idea, which means TIPC has the capability of self-automatic
>> configuration and automatically building a cluster without any manual
>> interfering. Is my understanding right?
>>
>> In addition, after a node has established links with other nodes with the
>> same net_id, user changes net_id through tipc_nl_net_set(). It means the
>> node cannot communicates with its originally linked nodes. I just found one
>> place in tipc_disc_rcv() where once net_id is different, discovery message is
>> directly dropped. But after links have been established and then net_id is
>> changed, I don't find where we handle the special case. In my mind, we
>> should first break the current links and then launch another request to re-
>> establish links with the new net_id.
>>
>> Moreover, we should immediately drop the message in data receive path
>> once net_id is changed. However, it seems we don't identify whether net_id
>> is same in tipc_rcv(). Please confirm this.
>>
>> Lastly, after zone concept is obsoleted, in the same Ethernet segment there
>> often exists many nodes whose net_id is different. Therefore, once net_id is
>> changed, we should permit the node to connect wither other nodes.
>>
>>
>> Thanks,
>> Ying
>>
>>> Signed-off-by: Jon Maloy <[email protected]>
>>> ---
>>> net/tipc/bearer.c | 24 +++++++++++++++---------
>>> net/tipc/net.h | 1 +
>>> net/tipc/udp_media.c | 13 +++++++++++++
>>> 3 files changed, 29 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index
>>> ae5b44c..f7d47c8 100644
>>> --- a/net/tipc/bearer.c
>>> +++ b/net/tipc/bearer.c
>>> @@ -243,12 +243,6 @@ static int tipc_enable_bearer(struct net *net, const
>> char *name,
>>> int res = -EINVAL;
>>> char *errstr = "";
>>>
>>> - if (!tipc_own_id(net)) {
>>> - errstr = "not supported in standalone mode";
>>> - res = -ENOPROTOOPT;
>>> - goto rejected;
>>> - }
>>> -
>>> if (!bearer_name_validate(name, &b_names)) {
>>> errstr = "illegal name";
>>> goto rejected;
>>> @@ -381,11 +375,13 @@ static void bearer_disable(struct net *net,
>>> struct tipc_bearer *b) int tipc_enable_l2_media(struct net *net, struct
>> tipc_bearer *b,
>>> struct nlattr *attr[])
>>> {
>>> + char *dev_name = strchr((const char *)b->name, ':') + 1;
>>> + int hwaddr_len = b->media->hwaddr_len;
>>> + u8 node_id[NODE_ID_LEN] = {0,};
>>> struct net_device *dev;
>>> - char *driver_name = strchr((const char *)b->name, ':') + 1;
>>>
>>> /* Find device with specified name */
>>> - dev = dev_get_by_name(net, driver_name);
>>> + dev = dev_get_by_name(net, dev_name);
>>> if (!dev)
>>> return -ENODEV;
>>> if (tipc_mtu_bad(dev, 0)) {
>>> @@ -393,6 +389,16 @@ int tipc_enable_l2_media(struct net *net, struct
>> tipc_bearer *b,
>>> return -EINVAL;
>>> }
>>>
>>> + /* Autoconfigure own node identity if needed */
>>> + if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
>>> + memcpy(node_id, dev->dev_addr, hwaddr_len);
>>> + tipc_net_init(net, node_id, 0);
>>> + }
>>> + if (!tipc_own_id(net)) {
>>> + pr_warn("Failed to obtain node identity\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> /* Associate TIPC bearer with L2 bearer */
>>> rcu_assign_pointer(b->media_ptr, dev);
>>> b->pt.dev = dev;
>>> @@ -400,7 +406,7 @@ int tipc_enable_l2_media(struct net *net, struct
>> tipc_bearer *b,
>>> b->pt.func = tipc_l2_rcv_msg;
>>> dev_add_pack(&b->pt);
>>> memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
>>> - memcpy(b->bcast_addr.value, dev->broadcast, b->media-
>>> hwaddr_len);
>>> + memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
>>> b->bcast_addr.media_id = b->media->type_id;
>>> b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
>>> b->mtu = dev->mtu;
>>> diff --git a/net/tipc/net.h b/net/tipc/net.h index 08efa60..09ad02b
>>> 100644
>>> --- a/net/tipc/net.h
>>> +++ b/net/tipc/net.h
>>> @@ -41,6 +41,7 @@
>>>
>>> extern const struct nla_policy tipc_nl_net_policy[];
>>>
>>> +int tipc_net_init(struct net *net, u8 *node_id, u32 addr);
>>> void tipc_net_finalize(struct net *net, u32 addr); void
>>> tipc_net_stop(struct net *net); int tipc_nl_net_dump(struct sk_buff
>>> *skb, struct netlink_callback *cb); diff --git a/net/tipc/udp_media.c
>>> b/net/tipc/udp_media.c index 3deabca..2c13b18 100644
>>> --- a/net/tipc/udp_media.c
>>> +++ b/net/tipc/udp_media.c
>>> @@ -47,6 +47,8 @@
>>> #include <net/addrconf.h>
>>> #include <linux/tipc_netlink.h>
>>> #include "core.h"
>>> +#include "addr.h"
>>> +#include "net.h"
>>> #include "bearer.h"
>>> #include "netlink.h"
>>> #include "msg.h"
>>> @@ -647,6 +649,7 @@ static int tipc_udp_enable(struct net *net, struct
>> tipc_bearer *b,
>>> struct udp_port_cfg udp_conf = {0};
>>> struct udp_tunnel_sock_cfg tuncfg = {NULL};
>>> struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
>>> + u8 node_id[NODE_ID_LEN] = {0,};
>>>
>>> ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
>>> if (!ub)
>>> @@ -677,6 +680,16 @@ static int tipc_udp_enable(struct net *net, struct
>> tipc_bearer *b,
>>> if (err)
>>> goto err;
>>>
>>> + /* Autoconfigure own node identity if needed */
>>> + if (!tipc_own_id(net)) {
>>> + memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
>>> + tipc_net_init(net, node_id, 0);
>>> + }
>>> + if (!tipc_own_id(net)) {
>>> + pr_warn("Failed to set node id, please configure
>> manually\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
>>> b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
>>> rcu_assign_pointer(b->media_ptr, ub);
>>>
------------------------------------------------------------------------------
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