From f6e0fb81298825e195888d2a32e6f7b6e64abf76 Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Wed, 2 Mar 2022 18:31:16 +0200 Subject: [PATCH] net: rtnetlink: Stop assuming that IFLA_OFFLOAD_XSTATS_* are dev-backed The IFLA_STATS_LINK_OFFLOAD_XSTATS attribute is a nest whose child attributes carry various special hardware statistics. The code that handles this nest was written with the idea that all these statistics would be exposed by the device driver of a physical netdevice. In the following patches, a new attribute is added to the abovementioned nest, which however can be defined for some soft netdevices. The NDO-based approach to querying these does not work, because it is not the soft netdevice driver that exposes these statistics, but an offloading NIC driver that does so. The current code does not scale well to this usage. Simply rewrite it back to the pattern seen in other fill-like and get_size-like functions elsewhere. Extract to helpers the code that is concerned with handling specifically NDO-backed statistics so that it can be easily reused should more such statistics be added. Signed-off-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 97 +++++++++++++++++++++++++--------------------------- 1 file changed, 47 insertions(+), 50 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index c484bf2..ad85879 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -5048,84 +5048,81 @@ static bool stats_attr_valid(unsigned int mask, int attrid, int idxattr) (!idxattr || idxattr == attrid); } -#define IFLA_OFFLOAD_XSTATS_FIRST (IFLA_OFFLOAD_XSTATS_UNSPEC + 1) -static int rtnl_get_offload_stats_attr_size(int attr_id) +static bool +rtnl_offload_xstats_have_ndo(const struct net_device *dev, int attr_id) { - switch (attr_id) { - case IFLA_OFFLOAD_XSTATS_CPU_HIT: - return sizeof(struct rtnl_link_stats64); - } + return dev->netdev_ops && + dev->netdev_ops->ndo_has_offload_stats && + dev->netdev_ops->ndo_get_offload_stats && + dev->netdev_ops->ndo_has_offload_stats(dev, attr_id); +} - return 0; +static unsigned int +rtnl_offload_xstats_get_size_ndo(const struct net_device *dev, int attr_id) +{ + return rtnl_offload_xstats_have_ndo(dev, attr_id) ? + sizeof(struct rtnl_link_stats64) : 0; } -static int rtnl_offload_xstats_fill(struct sk_buff *skb, struct net_device *dev, - int *prividx) +static int +rtnl_offload_xstats_fill_ndo(struct net_device *dev, int attr_id, + struct sk_buff *skb) { + unsigned int size = rtnl_offload_xstats_get_size_ndo(dev, attr_id); struct nlattr *attr = NULL; - int attr_id, size; void *attr_data; int err; - if (!(dev->netdev_ops && dev->netdev_ops->ndo_has_offload_stats && - dev->netdev_ops->ndo_get_offload_stats)) + if (!size) return -ENODATA; - for (attr_id = IFLA_OFFLOAD_XSTATS_FIRST; - attr_id <= IFLA_OFFLOAD_XSTATS_MAX; attr_id++) { - if (attr_id < *prividx) - continue; + attr = nla_reserve_64bit(skb, attr_id, size, + IFLA_OFFLOAD_XSTATS_UNSPEC); + if (!attr) + return -EMSGSIZE; - size = rtnl_get_offload_stats_attr_size(attr_id); - if (!size) - continue; + attr_data = nla_data(attr); + memset(attr_data, 0, size); - if (!dev->netdev_ops->ndo_has_offload_stats(dev, attr_id)) - continue; + err = dev->netdev_ops->ndo_get_offload_stats(attr_id, dev, attr_data); + if (err) + return err; - attr = nla_reserve_64bit(skb, attr_id, size, - IFLA_OFFLOAD_XSTATS_UNSPEC); - if (!attr) - goto nla_put_failure; + return 0; +} - attr_data = nla_data(attr); - memset(attr_data, 0, size); - err = dev->netdev_ops->ndo_get_offload_stats(attr_id, dev, - attr_data); - if (err) - goto get_offload_stats_failure; +static int rtnl_offload_xstats_fill(struct sk_buff *skb, struct net_device *dev, + int *prividx) +{ + int attr_id_cpu_hit = IFLA_OFFLOAD_XSTATS_CPU_HIT; + bool have_data = false; + int err; + + if (*prividx <= attr_id_cpu_hit) { + err = rtnl_offload_xstats_fill_ndo(dev, attr_id_cpu_hit, skb); + if (!err) { + have_data = true; + } else if (err != -ENODATA) { + *prividx = attr_id_cpu_hit; + return err; + } } - if (!attr) + if (!have_data) return -ENODATA; *prividx = 0; return 0; - -nla_put_failure: - err = -EMSGSIZE; -get_offload_stats_failure: - *prividx = attr_id; - return err; } static int rtnl_offload_xstats_get_size(const struct net_device *dev) { + int attr_id_cpu_hit = IFLA_OFFLOAD_XSTATS_CPU_HIT; int nla_size = 0; - int attr_id; int size; - if (!(dev->netdev_ops && dev->netdev_ops->ndo_has_offload_stats && - dev->netdev_ops->ndo_get_offload_stats)) - return 0; - - for (attr_id = IFLA_OFFLOAD_XSTATS_FIRST; - attr_id <= IFLA_OFFLOAD_XSTATS_MAX; attr_id++) { - if (!dev->netdev_ops->ndo_has_offload_stats(dev, attr_id)) - continue; - size = rtnl_get_offload_stats_attr_size(attr_id); - nla_size += nla_total_size_64bit(size); - } + size = rtnl_offload_xstats_get_size_ndo(dev, attr_id_cpu_hit); + nla_size += nla_total_size_64bit(size); if (nla_size != 0) nla_size += nla_total_size(0); -- 2.7.4