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Message-ID: <20240227150200.2814664-16-edumazet@google.com>
Date: Tue, 27 Feb 2024 15:02:00 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: David Ahern <dsahern@...nel.org>, Jiri Pirko <jiri@...dia.com>, netdev@...r.kernel.org,
eric.dumazet@...il.com, Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH v2 net-next 15/15] ipv6: use xa_array iterator to implement inet6_netconf_dump_devconf()
1) inet6_netconf_dump_devconf() can run under RCU protection
instead of RTNL.
2) properly return 0 at the end of a dump, avoiding an
an extra recvmsg() system call.
3) Do not use inet6_base_seq() anymore, for_each_netdev_dump()
has nice properties. Restarting a GETDEVCONF dump if a device has
been added/removed or if net->ipv6.dev_addr_genid has changed is moot.
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
net/ipv6/addrconf.c | 102 +++++++++++++++++++-------------------------
1 file changed, 44 insertions(+), 58 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 35246a1c42ea53b3410fab84ae037cbae4b76060..ae53c13ca12c1e05bba6c218ca20f6d66ab2c303 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -727,17 +727,18 @@ static u32 inet6_base_seq(const struct net *net)
return res;
}
-
static int inet6_netconf_dump_devconf(struct sk_buff *skb,
struct netlink_callback *cb)
{
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
- int h, s_h;
- int idx, s_idx;
+ struct {
+ unsigned long ifindex;
+ unsigned int all_default;
+ } *ctx = (void *)cb->ctx;
struct net_device *dev;
struct inet6_dev *idev;
- struct hlist_head *head;
+ int err = 0;
if (cb->strict_check) {
struct netlink_ext_ack *extack = cb->extack;
@@ -754,64 +755,48 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
}
}
- s_h = cb->args[0];
- s_idx = idx = cb->args[1];
-
- for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
- idx = 0;
- head = &net->dev_index_head[h];
- rcu_read_lock();
- cb->seq = inet6_base_seq(net);
- hlist_for_each_entry_rcu(dev, head, index_hlist) {
- if (idx < s_idx)
- goto cont;
- idev = __in6_dev_get(dev);
- if (!idev)
- goto cont;
-
- if (inet6_netconf_fill_devconf(skb, dev->ifindex,
- &idev->cnf,
- NETLINK_CB(cb->skb).portid,
- nlh->nlmsg_seq,
- RTM_NEWNETCONF,
- NLM_F_MULTI,
- NETCONFA_ALL) < 0) {
- rcu_read_unlock();
- goto done;
- }
- nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-cont:
- idx++;
- }
- rcu_read_unlock();
+ rcu_read_lock();
+ for_each_netdev_dump(net, dev, ctx->ifindex) {
+ idev = __in6_dev_get(dev);
+ if (!idev)
+ continue;
+ err = inet6_netconf_fill_devconf(skb, dev->ifindex,
+ &idev->cnf,
+ NETLINK_CB(cb->skb).portid,
+ nlh->nlmsg_seq,
+ RTM_NEWNETCONF,
+ NLM_F_MULTI,
+ NETCONFA_ALL);
+ if (err < 0)
+ goto done;
}
- if (h == NETDEV_HASHENTRIES) {
- if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
- net->ipv6.devconf_all,
- NETLINK_CB(cb->skb).portid,
- nlh->nlmsg_seq,
- RTM_NEWNETCONF, NLM_F_MULTI,
- NETCONFA_ALL) < 0)
+ if (ctx->all_default == 0) {
+ err = inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
+ net->ipv6.devconf_all,
+ NETLINK_CB(cb->skb).portid,
+ nlh->nlmsg_seq,
+ RTM_NEWNETCONF, NLM_F_MULTI,
+ NETCONFA_ALL);
+ if (err < 0)
goto done;
- else
- h++;
- }
- if (h == NETDEV_HASHENTRIES + 1) {
- if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
- net->ipv6.devconf_dflt,
- NETLINK_CB(cb->skb).portid,
- nlh->nlmsg_seq,
- RTM_NEWNETCONF, NLM_F_MULTI,
- NETCONFA_ALL) < 0)
+ ctx->all_default++;
+ }
+ if (ctx->all_default == 1) {
+ err = inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
+ net->ipv6.devconf_dflt,
+ NETLINK_CB(cb->skb).portid,
+ nlh->nlmsg_seq,
+ RTM_NEWNETCONF, NLM_F_MULTI,
+ NETCONFA_ALL);
+ if (err < 0)
goto done;
- else
- h++;
+ ctx->all_default++;
}
done:
- cb->args[0] = h;
- cb->args[1] = idx;
-
- return skb->len;
+ if (err < 0 && likely(skb->len))
+ err = skb->len;
+ rcu_read_unlock();
+ return err;
}
#ifdef CONFIG_SYSCTL
@@ -7501,7 +7486,8 @@ int __init addrconf_init(void)
err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETNETCONF,
inet6_netconf_get_devconf,
inet6_netconf_dump_devconf,
- RTNL_FLAG_DOIT_UNLOCKED);
+ RTNL_FLAG_DOIT_UNLOCKED |
+ RTNL_FLAG_DUMP_UNLOCKED);
if (err < 0)
goto errout;
err = ipv6_addr_label_rtnl_register();
--
2.44.0.rc1.240.g4c46232300-goog
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