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| author | Eric Dumazet <edumazet@google.com> | 2026-05-11 07:02:44 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-12 18:30:26 -0700 |
| commit | b588019e85f490696bf19f0747e93f14b1563927 (patch) | |
| tree | 69616dcd4929fdcd3e3e65bf7d2324210e4639c3 /net/core/rtnetlink.c | |
| parent | 9edbdd2c9d02667b3953997440036ea2ba932b4d (diff) | |
| download | linux-next-b588019e85f490696bf19f0747e93f14b1563927.tar.gz linux-next-b588019e85f490696bf19f0747e93f14b1563927.zip | |
rtnetlink: add RTEXT_FILTER_NAME_ONLY support
iproute2 can spend considerable amount of time in ll_init_map()
or ll_link_get() to dump verbose netdev attributes, contributing
to RTNL pressure.
Add RTEXT_FILTER_NAME_ONLY new flag so that rtnl_fill_ifinfo()
limits its output to:
- struct nlmsghdr
- IFLA_IFNAME
- IFLA_PROP_LIST (alternate names)
We can later avoid using RTNL when RTEXT_FILTER_NAME_ONLY
is requested, as none of these attributes need RTNL.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260511070244.971028-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/rtnetlink.c')
| -rw-r--r-- | net/core/rtnetlink.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index df042da422ef..70fde922b371 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1295,7 +1295,12 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, size = NLMSG_ALIGN(sizeof(struct ifinfomsg)) + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */ - + nla_total_size(IFALIASZ) /* IFLA_IFALIAS */ + + rtnl_prop_list_size(dev); + + if (ext_filter_mask & RTEXT_FILTER_NAME_ONLY) + return size; + + size += nla_total_size(IFALIASZ) /* IFLA_IFALIAS */ + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */ + nla_total_size_64bit(sizeof(struct rtnl_link_ifmap)) + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */ @@ -1342,7 +1347,6 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + nla_total_size(4) /* IFLA_CARRIER_DOWN_COUNT */ + nla_total_size(4) /* IFLA_MIN_MTU */ + nla_total_size(4) /* IFLA_MAX_MTU */ - + rtnl_prop_list_size(dev) + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */ + rtnl_devlink_port_size(dev) + rtnl_dpll_pin_size(dev) @@ -1941,15 +1945,18 @@ static int rtnl_fill_alt_ifnames(struct sk_buff *skb, struct netdev_name_node *name_node; int count = 0; + rcu_read_lock(); list_for_each_entry_rcu(name_node, &dev->name_node->list, list) { - if (nla_put_string(skb, IFLA_ALT_IFNAME, name_node->name)) + if (nla_put_string(skb, IFLA_ALT_IFNAME, name_node->name)) { + rcu_read_unlock(); return -EMSGSIZE; + } count++; } + rcu_read_unlock(); return count; } -/* RCU protected. */ static int rtnl_fill_prop_list(struct sk_buff *skb, const struct net_device *dev) { @@ -2072,13 +2079,20 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, ifm->ifi_flags = netif_get_flags(dev); ifm->ifi_change = change; - if (tgt_netnsid >= 0 && nla_put_s32(skb, IFLA_TARGET_NETNSID, tgt_netnsid)) - goto nla_put_failure; - netdev_copy_name(dev, devname); if (nla_put_string(skb, IFLA_IFNAME, devname)) goto nla_put_failure; + if (rtnl_fill_prop_list(skb, dev)) + goto nla_put_failure; + + if (ext_filter_mask & RTEXT_FILTER_NAME_ONLY) + goto end; + + if (tgt_netnsid >= 0 && + nla_put_s32(skb, IFLA_TARGET_NETNSID, tgt_netnsid)) + goto nla_put_failure; + if (nla_put_u32(skb, IFLA_TXQLEN, READ_ONCE(dev->tx_queue_len)) || nla_put_u8(skb, IFLA_OPERSTATE, netif_running(dev) ? READ_ONCE(dev->operstate) : @@ -2191,8 +2205,6 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, goto nla_put_failure_rcu; if (rtnl_fill_link_ifmap(skb, dev)) goto nla_put_failure_rcu; - if (rtnl_fill_prop_list(skb, dev)) - goto nla_put_failure_rcu; rcu_read_unlock(); if (dev->dev.parent && @@ -2211,6 +2223,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, if (rtnl_fill_dpll_pin(skb, dev)) goto nla_put_failure; +end: nlmsg_end(skb, nlh); return 0; |