Quelle  channels.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only

#include <net/xdp_sock_drv.h>

#include "netlink.h"
#include "common.h"

struct channels_req_info {
 struct ethnl_req_info  base;
};

struct channels_reply_data {
 struct ethnl_reply_data  base;
 struct ethtool_channels  channels;
};

#define CHANNELS_REPDATA(__reply_base) \
 container_of(__reply_base, struct channels_reply_data, base)

const struct nla_policy ethnl_channels_get_policy[] = {
 [ETHTOOL_A_CHANNELS_HEADER]  =
  NLA_POLICY_NESTED(ethnl_header_policy),
};

static int channels_prepare_data(const struct ethnl_req_info *req_base,
     struct ethnl_reply_data *reply_base,
     const struct genl_info *info)
{
 struct channels_reply_data *data = CHANNELS_REPDATA(reply_base);
 struct net_device *dev = reply_base->dev;
 int ret;

 if (!dev->ethtool_ops->get_channels)
  return -EOPNOTSUPP;
 ret = ethnl_ops_begin(dev);
 if (ret < 0)
  return ret;
 dev->ethtool_ops->get_channels(dev, &data->channels);
 ethnl_ops_complete(dev);

 return 0;
}

static int channels_reply_size(const struct ethnl_req_info *req_base,
          const struct ethnl_reply_data *reply_base)
{
 return nla_total_size(sizeof(u32)) + /* _CHANNELS_RX_MAX */
        nla_total_size(sizeof(u32)) + /* _CHANNELS_TX_MAX */
        nla_total_size(sizeof(u32)) + /* _CHANNELS_OTHER_MAX */
        nla_total_size(sizeof(u32)) + /* _CHANNELS_COMBINED_MAX */
        nla_total_size(sizeof(u32)) + /* _CHANNELS_RX_COUNT */
        nla_total_size(sizeof(u32)) + /* _CHANNELS_TX_COUNT */
        nla_total_size(sizeof(u32)) + /* _CHANNELS_OTHER_COUNT */
        nla_total_size(sizeof(u32)); /* _CHANNELS_COMBINED_COUNT */
}

static int channels_fill_reply(struct sk_buff *skb,
          const struct ethnl_req_info *req_base,
          const struct ethnl_reply_data *reply_base)
{
 const struct channels_reply_data *data = CHANNELS_REPDATA(reply_base);
 const struct ethtool_channels *channels = &data->channels;

 if ((channels->max_rx &&
      (nla_put_u32(skb, ETHTOOL_A_CHANNELS_RX_MAX,
     channels->max_rx) ||
       nla_put_u32(skb, ETHTOOL_A_CHANNELS_RX_COUNT,
     channels->rx_count))) ||
     (channels->max_tx &&
      (nla_put_u32(skb, ETHTOOL_A_CHANNELS_TX_MAX,
     channels->max_tx) ||
       nla_put_u32(skb, ETHTOOL_A_CHANNELS_TX_COUNT,
     channels->tx_count))) ||
     (channels->max_other &&
      (nla_put_u32(skb, ETHTOOL_A_CHANNELS_OTHER_MAX,
     channels->max_other) ||
       nla_put_u32(skb, ETHTOOL_A_CHANNELS_OTHER_COUNT,
     channels->other_count))) ||
     (channels->max_combined &&
      (nla_put_u32(skb, ETHTOOL_A_CHANNELS_COMBINED_MAX,
     channels->max_combined) ||
       nla_put_u32(skb, ETHTOOL_A_CHANNELS_COMBINED_COUNT,
     channels->combined_count))))
  return -EMSGSIZE;

 return 0;
}

/* CHANNELS_SET */

const struct nla_policy ethnl_channels_set_policy[] = {
 [ETHTOOL_A_CHANNELS_HEADER]  =
  NLA_POLICY_NESTED(ethnl_header_policy),
 [ETHTOOL_A_CHANNELS_RX_COUNT]  = { .type = NLA_U32 },
 [ETHTOOL_A_CHANNELS_TX_COUNT]  = { .type = NLA_U32 },
 [ETHTOOL_A_CHANNELS_OTHER_COUNT] = { .type = NLA_U32 },
 [ETHTOOL_A_CHANNELS_COMBINED_COUNT] = { .type = NLA_U32 },
};

static int
ethnl_set_channels_validate(struct ethnl_req_info *req_info,
       struct genl_info *info)
{
 const struct ethtool_ops *ops = req_info->dev->ethtool_ops;

 return ops->get_channels && ops->set_channels ? 1 : -EOPNOTSUPP;
}

static int
ethnl_set_channels(struct ethnl_req_info *req_info, struct genl_info *info)
{
 unsigned int from_channel, old_total, i;
 bool mod = false, mod_combined = false;
 struct net_device *dev = req_info->dev;
 struct ethtool_channels channels = {};
 struct nlattr **tb = info->attrs;
 u32 err_attr;
 int ret;

 dev->ethtool_ops->get_channels(dev, &channels);
 old_total = channels.combined_count +
      max(channels.rx_count, channels.tx_count);

 ethnl_update_u32(&channels.rx_count, tb[ETHTOOL_A_CHANNELS_RX_COUNT],
    &mod);
 ethnl_update_u32(&channels.tx_count, tb[ETHTOOL_A_CHANNELS_TX_COUNT],
    &mod);
 ethnl_update_u32(&channels.other_count,
    tb[ETHTOOL_A_CHANNELS_OTHER_COUNT], &mod);
 ethnl_update_u32(&channels.combined_count,
    tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT], &mod_combined);
 mod |= mod_combined;
 if (!mod)
  return 0;

 /* ensure new channel counts are within limits */
 if (channels.rx_count > channels.max_rx)
  err_attr = ETHTOOL_A_CHANNELS_RX_COUNT;
 else if (channels.tx_count > channels.max_tx)
  err_attr = ETHTOOL_A_CHANNELS_TX_COUNT;
 else if (channels.other_count > channels.max_other)
  err_attr = ETHTOOL_A_CHANNELS_OTHER_COUNT;
 else if (channels.combined_count > channels.max_combined)
  err_attr = ETHTOOL_A_CHANNELS_COMBINED_COUNT;
 else
  err_attr = 0;
 if (err_attr) {
  NL_SET_ERR_MSG_ATTR(info->extack, tb[err_attr],
        "requested channel count exceeds maximum");
  return -EINVAL;
 }

 /* ensure there is at least one RX and one TX channel */
 if (!channels.combined_count && !channels.rx_count)
  err_attr = ETHTOOL_A_CHANNELS_RX_COUNT;
 else if (!channels.combined_count && !channels.tx_count)
  err_attr = ETHTOOL_A_CHANNELS_TX_COUNT;
 else
  err_attr = 0;
 if (err_attr) {
  if (mod_combined)
   err_attr = ETHTOOL_A_CHANNELS_COMBINED_COUNT;
  NL_SET_ERR_MSG_ATTR(info->extack, tb[err_attr],
        "requested channel counts would result in no RX or TX channel being configured");
  return -EINVAL;
 }

 ret = ethtool_check_max_channel(dev, channels, info);
 if (ret)
  return ret;

 /* Disabling channels, query zero-copy AF_XDP sockets */
 from_channel = channels.combined_count +
         min(channels.rx_count, channels.tx_count);
 for (i = from_channel; i < old_total; i++)
  if (xsk_get_pool_from_qid(dev, i)) {
   GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing zerocopy AF_XDP sockets");
   return -EINVAL;
  }

 ret = dev->ethtool_ops->set_channels(dev, &channels);
 return ret < 0 ? ret : 1;
}

const struct ethnl_request_ops ethnl_channels_request_ops = {
 .request_cmd  = ETHTOOL_MSG_CHANNELS_GET,
 .reply_cmd  = ETHTOOL_MSG_CHANNELS_GET_REPLY,
 .hdr_attr  = ETHTOOL_A_CHANNELS_HEADER,
 .req_info_size  = sizeof(struct channels_req_info),
 .reply_data_size = sizeof(struct channels_reply_data),

 .prepare_data  = channels_prepare_data,
 .reply_size  = channels_reply_size,
 .fill_reply  = channels_fill_reply,

 .set_validate  = ethnl_set_channels_validate,
 .set   = ethnl_set_channels,
 .set_ntf_cmd  = ETHTOOL_MSG_CHANNELS_NTF,
};