* [PATCH net v2] rtnetlink: enable alt_ifname for setlink/newlink
@ 2022-04-01 15:39 Florent Fourcot
2022-04-01 17:43 ` Jakub Kicinski
0 siblings, 1 reply; 4+ messages in thread
From: Florent Fourcot @ 2022-04-01 15:39 UTC (permalink / raw)
To: netdev; +Cc: cong.wang, edumazet, Florent Fourcot, Jiri Pirko, Brian Baboch
buffer called "ifname" given in function rtnl_dev_get
is always valid when called by setlink/newlink,
but contains only empty string when IFLA_IFNAME is not given. So
IFLA_ALT_IFNAME is always ignored
This patch fixes rtnl_dev_get function with a remove of ifname argument,
and move ifname copy in do_setlink when required
Changes in v2:
* Remove ifname argument in rtnl_dev_get/do_setlink
functions (simplify code)
Fixes: 76c9ac0ee878 ("net: rtnetlink: add possibility to use alternative names as message handle")
CC: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
---
net/core/rtnetlink.c | 65 +++++++++++++++++++-------------------------
1 file changed, 28 insertions(+), 37 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index be443cfc77d4..563fdd997f62 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2607,17 +2607,23 @@ static int do_set_proto_down(struct net_device *dev,
static int do_setlink(const struct sk_buff *skb,
struct net_device *dev, struct ifinfomsg *ifm,
struct netlink_ext_ack *extack,
- struct nlattr **tb, char *ifname, int status)
+ struct nlattr **tb, int status)
{
const struct net_device_ops *ops = dev->netdev_ops;
+ char ifname[IFNAMSIZ];
int err;
err = validate_linkmsg(dev, tb, extack);
if (err < 0)
return err;
+ if (tb[IFLA_IFNAME])
+ nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
+ else
+ ifname[0] = '\0';
+
if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD] || tb[IFLA_TARGET_NETNSID]) {
- const char *pat = ifname && ifname[0] ? ifname : NULL;
+ const char *pat = ifname[0] ? ifname : NULL;
struct net *net;
int new_ifindex;
@@ -2974,20 +2980,16 @@ static int do_setlink(const struct sk_buff *skb,
static struct net_device *rtnl_dev_get(struct net *net,
struct nlattr *ifname_attr,
- struct nlattr *altifname_attr,
- char *ifname)
+ struct nlattr *altifname_attr)
{
- char buffer[ALTIFNAMSIZ];
+ char ifname[ALTIFNAMSIZ];
- if (!ifname) {
- ifname = buffer;
- if (ifname_attr)
- nla_strscpy(ifname, ifname_attr, IFNAMSIZ);
- else if (altifname_attr)
- nla_strscpy(ifname, altifname_attr, ALTIFNAMSIZ);
- else
- return NULL;
- }
+ if (ifname_attr)
+ nla_strscpy(ifname, ifname_attr, IFNAMSIZ);
+ else if (altifname_attr)
+ nla_strscpy(ifname, altifname_attr, ALTIFNAMSIZ);
+ else
+ return NULL;
return __dev_get_by_name(net, ifname);
}
@@ -3000,7 +3002,6 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct net_device *dev;
int err;
struct nlattr *tb[IFLA_MAX+1];
- char ifname[IFNAMSIZ];
err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
ifla_policy, extack);
@@ -3011,17 +3012,12 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
if (err < 0)
goto errout;
- if (tb[IFLA_IFNAME])
- nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
- else
- ifname[0] = '\0';
-
err = -EINVAL;
ifm = nlmsg_data(nlh);
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(net, ifm->ifi_index);
else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
- dev = rtnl_dev_get(net, NULL, tb[IFLA_ALT_IFNAME], ifname);
+ dev = rtnl_dev_get(net, tb[IFLA_IFNAME], tb[IFLA_ALT_IFNAME]);
else
goto errout;
@@ -3030,7 +3026,7 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
goto errout;
}
- err = do_setlink(skb, dev, ifm, extack, tb, ifname, 0);
+ err = do_setlink(skb, dev, ifm, extack, tb, 0);
errout:
return err;
}
@@ -3119,8 +3115,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(tgt_net, ifm->ifi_index);
else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
- dev = rtnl_dev_get(net, tb[IFLA_IFNAME],
- tb[IFLA_ALT_IFNAME], NULL);
+ dev = rtnl_dev_get(net, tb[IFLA_IFNAME], tb[IFLA_ALT_IFNAME]);
else if (tb[IFLA_GROUP])
err = rtnl_group_dellink(tgt_net, nla_get_u32(tb[IFLA_GROUP]));
else
@@ -3262,7 +3257,7 @@ static int rtnl_group_changelink(const struct sk_buff *skb,
for_each_netdev_safe(net, dev, aux) {
if (dev->group == group) {
- err = do_setlink(skb, dev, ifm, extack, tb, NULL, 0);
+ err = do_setlink(skb, dev, ifm, extack, tb, 0);
if (err < 0)
return err;
}
@@ -3303,16 +3298,11 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
if (err < 0)
return err;
- if (tb[IFLA_IFNAME])
- nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
- else
- ifname[0] = '\0';
-
ifm = nlmsg_data(nlh);
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(net, ifm->ifi_index);
else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
- dev = rtnl_dev_get(net, NULL, tb[IFLA_ALT_IFNAME], ifname);
+ dev = rtnl_dev_get(net, tb[IFLA_IFNAME], tb[IFLA_ALT_IFNAME]);
else
dev = NULL;
@@ -3413,7 +3403,7 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
status |= DO_SETLINK_NOTIFY;
}
- return do_setlink(skb, dev, ifm, extack, tb, ifname, status);
+ return do_setlink(skb, dev, ifm, extack, tb, status);
}
if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
@@ -3450,7 +3440,10 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
if (!ops->alloc && !ops->setup)
return -EOPNOTSUPP;
- if (!ifname[0]) {
+ if (tb[IFLA_IFNAME]) {
+ nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
+ }
+ else {
snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
name_assign_type = NET_NAME_ENUM;
}
@@ -3622,8 +3615,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(tgt_net, ifm->ifi_index);
else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
- dev = rtnl_dev_get(tgt_net, tb[IFLA_IFNAME],
- tb[IFLA_ALT_IFNAME], NULL);
+ dev = rtnl_dev_get(tgt_net, tb[IFLA_IFNAME], tb[IFLA_ALT_IFNAME]);
else
goto out;
@@ -3718,8 +3710,7 @@ static int rtnl_linkprop(int cmd, struct sk_buff *skb, struct nlmsghdr *nlh,
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(net, ifm->ifi_index);
else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
- dev = rtnl_dev_get(net, tb[IFLA_IFNAME],
- tb[IFLA_ALT_IFNAME], NULL);
+ dev = rtnl_dev_get(net, tb[IFLA_IFNAME], tb[IFLA_ALT_IFNAME]);
else
return -EINVAL;
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net v2] rtnetlink: enable alt_ifname for setlink/newlink
2022-04-01 15:39 [PATCH net v2] rtnetlink: enable alt_ifname for setlink/newlink Florent Fourcot
@ 2022-04-01 17:43 ` Jakub Kicinski
2022-04-01 21:02 ` Florent Fourcot
0 siblings, 1 reply; 4+ messages in thread
From: Jakub Kicinski @ 2022-04-01 17:43 UTC (permalink / raw)
To: Florent Fourcot; +Cc: netdev, cong.wang, edumazet, Jiri Pirko, Brian Baboch
On Fri, 1 Apr 2022 17:39:39 +0200 Florent Fourcot wrote:
> buffer called "ifname" given in function rtnl_dev_get
> is always valid when called by setlink/newlink,
> but contains only empty string when IFLA_IFNAME is not given. So
> IFLA_ALT_IFNAME is always ignored
>
> This patch fixes rtnl_dev_get function with a remove of ifname argument,
> and move ifname copy in do_setlink when required
>
> Changes in v2:
> * Remove ifname argument in rtnl_dev_get/do_setlink
> functions (simplify code)
>
> Fixes: 76c9ac0ee878 ("net: rtnetlink: add possibility to use alternative names as message handle")
> CC: Jiri Pirko <jiri@mellanox.com>
> Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
> Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
> @@ -3262,7 +3257,7 @@ static int rtnl_group_changelink(const struct sk_buff *skb,
>
> for_each_netdev_safe(net, dev, aux) {
> if (dev->group == group) {
> - err = do_setlink(skb, dev, ifm, extack, tb, NULL, 0);
> + err = do_setlink(skb, dev, ifm, extack, tb, 0);
This part depends on your other change, right? Do you care about this
getting into stable? Otherwise we can downgrade it from a fix to -next
and merge after your other patch. It never worked so we can go either
way on it being a fix. Actually leaning slightly towards it _not_ being
a fix.
> if (err < 0)
> return err;
> }
> @@ -3450,7 +3440,10 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
> if (!ops->alloc && !ops->setup)
> return -EOPNOTSUPP;
>
> - if (!ifname[0]) {
> + if (tb[IFLA_IFNAME]) {
> + nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
> + }
> + else {
Formatting slightly off here, should be
} else {
> snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
> name_assign_type = NET_NAME_ENUM;
> }
> @@ -3622,8 +3615,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
> if (ifm->ifi_index > 0)
> dev = __dev_get_by_index(tgt_net, ifm->ifi_index);
> else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
> - dev = rtnl_dev_get(tgt_net, tb[IFLA_IFNAME],
> - tb[IFLA_ALT_IFNAME], NULL);
> + dev = rtnl_dev_get(tgt_net, tb[IFLA_IFNAME], tb[IFLA_ALT_IFNAME]);
How about we pass tb and extract IFLA_IFNAME and IFLA_ALT_IFNAME inside
rtnl_dev_get()? All callers seem to pass the same args now.
> else
> goto out;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net v2] rtnetlink: enable alt_ifname for setlink/newlink
2022-04-01 17:43 ` Jakub Kicinski
@ 2022-04-01 21:02 ` Florent Fourcot
2022-04-01 22:09 ` Jakub Kicinski
0 siblings, 1 reply; 4+ messages in thread
From: Florent Fourcot @ 2022-04-01 21:02 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: netdev, cong.wang, edumazet, Jiri Pirko, Brian Baboch
>
> This part depends on your other change, right? Do you care about this
> getting into stable? Otherwise we can downgrade it from a fix to -next
> and merge after your other patch. It never worked so we can go either
> way on it being a fix. Actually leaning slightly towards it _not_ being
> a fix.
>
I don't really care about getting this into stable, so I will resubmit
for net-next when opened.
Should I drop "Fixes" tag? Alternatives ifname feature never worked for
setlink/newlink, but 76c9ac0ee878 claimed it was.
>
> Formatting slightly off here, should be
>
> } else {
>
Thanks
>
> How about we pass tb and extract IFLA_IFNAME and IFLA_ALT_IFNAME inside
> rtnl_dev_get()? All callers seem to pass the same args now.
>
You are right, it's a good idea for the v3
Best regards,
--
Florent Fourcot
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net v2] rtnetlink: enable alt_ifname for setlink/newlink
2022-04-01 21:02 ` Florent Fourcot
@ 2022-04-01 22:09 ` Jakub Kicinski
0 siblings, 0 replies; 4+ messages in thread
From: Jakub Kicinski @ 2022-04-01 22:09 UTC (permalink / raw)
To: Florent Fourcot; +Cc: netdev, cong.wang, edumazet, Jiri Pirko, Brian Baboch
On Fri, 1 Apr 2022 23:02:39 +0200 Florent Fourcot wrote:
> I don't really care about getting this into stable, so I will resubmit
> for net-next when opened.
> Should I drop "Fixes" tag?
Yup! No fixes tag if it's going in to net-next.
> Alternatives ifname feature never worked for setlink/newlink,
> but 76c9ac0ee878 claimed it was.
I wonder what the story was there. I think it "works" in that ip link
accept altnames, but IIUC that's because it does a get first and
resolves the ifindex.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-04-01 15:39 [PATCH net v2] rtnetlink: enable alt_ifname for setlink/newlink Florent Fourcot
2022-04-01 17:43 ` Jakub Kicinski
2022-04-01 21:02 ` Florent Fourcot
2022-04-01 22:09 ` Jakub Kicinski
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