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https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 18:24:14 +08:00
nl80211: use small state buffer for wiphy_dump
Avoid parsing the original dump message again and again by allocating a small state struct that is used by the functions involved in the dump, storing this struct in cb->args[0]. This reduces the memory allocation size as well. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg
parent
f93beba705
commit
86e8cf98de
@ -1111,10 +1111,16 @@ nl80211_send_mgmt_stypes(struct sk_buff *msg,
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return 0;
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}
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struct nl80211_dump_wiphy_state {
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s64 filter_wiphy;
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long start;
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long split_start, band_start, chan_start;
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bool split;
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};
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static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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struct sk_buff *msg, u32 portid, u32 seq,
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int flags, bool split, long *split_start,
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long *band_start, long *chan_start)
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int flags, struct nl80211_dump_wiphy_state *state)
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{
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void *hdr;
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struct nlattr *nl_bands, *nl_band;
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@ -1125,19 +1131,14 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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int i;
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const struct ieee80211_txrx_stypes *mgmt_stypes =
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dev->wiphy.mgmt_stypes;
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long start = 0, start_chan = 0, start_band = 0;
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u32 features;
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hdr = nl80211hdr_put(msg, portid, seq, flags, NL80211_CMD_NEW_WIPHY);
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if (!hdr)
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return -ENOBUFS;
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/* allow always using the variables */
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if (!split) {
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split_start = &start;
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band_start = &start_band;
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chan_start = &start_chan;
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}
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if (WARN_ON(!state))
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return -EINVAL;
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if (nla_put_u32(msg, NL80211_ATTR_WIPHY, dev->wiphy_idx) ||
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nla_put_string(msg, NL80211_ATTR_WIPHY_NAME,
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@ -1146,7 +1147,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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cfg80211_rdev_list_generation))
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goto nla_put_failure;
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switch (*split_start) {
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switch (state->split_start) {
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case 0:
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if (nla_put_u8(msg, NL80211_ATTR_WIPHY_RETRY_SHORT,
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dev->wiphy.retry_short) ||
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@ -1192,8 +1193,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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nla_put_flag(msg, WIPHY_FLAG_SUPPORTS_5_10_MHZ))
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goto nla_put_failure;
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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case 1:
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if (nla_put(msg, NL80211_ATTR_CIPHER_SUITES,
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@ -1237,22 +1238,23 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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}
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}
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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case 2:
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if (nl80211_put_iftypes(msg, NL80211_ATTR_SUPPORTED_IFTYPES,
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dev->wiphy.interface_modes))
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goto nla_put_failure;
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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case 3:
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nl_bands = nla_nest_start(msg, NL80211_ATTR_WIPHY_BANDS);
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if (!nl_bands)
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goto nla_put_failure;
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for (band = *band_start; band < IEEE80211_NUM_BANDS; band++) {
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for (band = state->band_start;
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band < IEEE80211_NUM_BANDS; band++) {
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struct ieee80211_supported_band *sband;
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sband = dev->wiphy.bands[band];
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@ -1264,12 +1266,12 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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if (!nl_band)
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goto nla_put_failure;
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switch (*chan_start) {
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switch (state->chan_start) {
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case 0:
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if (nl80211_send_band_rateinfo(msg, sband))
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goto nla_put_failure;
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(*chan_start)++;
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if (split)
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state->chan_start++;
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if (state->split)
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break;
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default:
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/* add frequencies */
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@ -1278,7 +1280,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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if (!nl_freqs)
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goto nla_put_failure;
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for (i = *chan_start - 1;
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for (i = state->chan_start - 1;
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i < sband->n_channels;
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i++) {
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nl_freq = nla_nest_start(msg, i);
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@ -1287,26 +1289,27 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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chan = &sband->channels[i];
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if (nl80211_msg_put_channel(msg, chan,
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split))
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if (nl80211_msg_put_channel(
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msg, chan,
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state->split))
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goto nla_put_failure;
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nla_nest_end(msg, nl_freq);
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if (split)
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if (state->split)
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break;
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}
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if (i < sband->n_channels)
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*chan_start = i + 2;
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state->chan_start = i + 2;
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else
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*chan_start = 0;
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state->chan_start = 0;
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nla_nest_end(msg, nl_freqs);
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}
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nla_nest_end(msg, nl_band);
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if (split) {
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if (state->split) {
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/* start again here */
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if (*chan_start)
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if (state->chan_start)
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band--;
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break;
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}
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@ -1314,14 +1317,14 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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nla_nest_end(msg, nl_bands);
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if (band < IEEE80211_NUM_BANDS)
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*band_start = band + 1;
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state->band_start = band + 1;
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else
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*band_start = 0;
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state->band_start = 0;
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/* if bands & channels are done, continue outside */
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if (*band_start == 0 && *chan_start == 0)
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(*split_start)++;
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if (split)
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if (state->band_start == 0 && state->chan_start == 0)
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state->split_start++;
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if (state->split)
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break;
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case 4:
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nl_cmds = nla_nest_start(msg, NL80211_ATTR_SUPPORTED_COMMANDS);
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@ -1387,7 +1390,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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}
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CMD(start_p2p_device, START_P2P_DEVICE);
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CMD(set_mcast_rate, SET_MCAST_RATE);
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if (split) {
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if (state->split) {
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CMD(crit_proto_start, CRIT_PROTOCOL_START);
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CMD(crit_proto_stop, CRIT_PROTOCOL_STOP);
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}
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@ -1411,8 +1414,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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}
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nla_nest_end(msg, nl_cmds);
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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case 5:
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if (dev->ops->remain_on_channel &&
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@ -1428,29 +1431,30 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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if (nl80211_send_mgmt_stypes(msg, mgmt_stypes))
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goto nla_put_failure;
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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case 6:
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#ifdef CONFIG_PM
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if (nl80211_send_wowlan(msg, dev, split))
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if (nl80211_send_wowlan(msg, dev, state->split))
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goto nla_put_failure;
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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#else
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(*split_start)++;
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state->split_start++;
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#endif
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case 7:
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if (nl80211_put_iftypes(msg, NL80211_ATTR_SOFTWARE_IFTYPES,
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dev->wiphy.software_iftypes))
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goto nla_put_failure;
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if (nl80211_put_iface_combinations(&dev->wiphy, msg, split))
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if (nl80211_put_iface_combinations(&dev->wiphy, msg,
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state->split))
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goto nla_put_failure;
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(*split_start)++;
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if (split)
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state->split_start++;
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if (state->split)
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break;
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case 8:
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if ((dev->wiphy.flags & WIPHY_FLAG_HAVE_AP_SME) &&
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@ -1464,7 +1468,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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* dump is split, otherwise it makes it too big. Therefore
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* only advertise it in that case.
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*/
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if (split)
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if (state->split)
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features |= NL80211_FEATURE_ADVERTISE_CHAN_LIMITS;
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if (nla_put_u32(msg, NL80211_ATTR_FEATURE_FLAGS, features))
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goto nla_put_failure;
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@ -1491,7 +1495,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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* case we'll continue with more data in the next round,
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* but break unconditionally so unsplit data stops here.
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*/
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(*split_start)++;
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state->split_start++;
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break;
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case 9:
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if (dev->wiphy.extended_capabilities &&
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@ -1510,7 +1514,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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goto nla_put_failure;
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/* done */
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*split_start = 0;
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state->split_start = 0;
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break;
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}
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return genlmsg_end(msg, hdr);
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@ -1520,66 +1524,76 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
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return -EMSGSIZE;
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}
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static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
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static int nl80211_dump_wiphy_parse(struct sk_buff *skb,
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struct netlink_callback *cb,
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struct nl80211_dump_wiphy_state *state)
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{
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int idx = 0, ret;
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int start = cb->args[0];
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struct cfg80211_registered_device *dev;
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s64 filter_wiphy = -1;
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bool split = false;
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struct nlattr **tb;
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int res;
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struct nlattr **tb = nl80211_fam.attrbuf;
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int ret = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
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tb, nl80211_fam.maxattr, nl80211_policy);
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/* ignore parse errors for backward compatibility */
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if (ret)
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return 0;
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/* will be zeroed in nlmsg_parse() */
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tb = kmalloc(sizeof(*tb) * (NL80211_ATTR_MAX + 1), GFP_KERNEL);
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if (!tb)
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return -ENOMEM;
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rtnl_lock();
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res = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
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tb, NL80211_ATTR_MAX, nl80211_policy);
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if (res == 0) {
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split = tb[NL80211_ATTR_SPLIT_WIPHY_DUMP];
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state->split = tb[NL80211_ATTR_SPLIT_WIPHY_DUMP];
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if (tb[NL80211_ATTR_WIPHY])
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filter_wiphy = nla_get_u32(tb[NL80211_ATTR_WIPHY]);
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state->filter_wiphy = nla_get_u32(tb[NL80211_ATTR_WIPHY]);
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if (tb[NL80211_ATTR_WDEV])
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filter_wiphy = nla_get_u64(tb[NL80211_ATTR_WDEV]) >> 32;
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state->filter_wiphy = nla_get_u64(tb[NL80211_ATTR_WDEV]) >> 32;
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if (tb[NL80211_ATTR_IFINDEX]) {
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struct net_device *netdev;
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struct cfg80211_registered_device *rdev;
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int ifidx = nla_get_u32(tb[NL80211_ATTR_IFINDEX]);
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netdev = dev_get_by_index(sock_net(skb->sk), ifidx);
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if (!netdev) {
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rtnl_unlock();
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kfree(tb);
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if (!netdev)
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return -ENODEV;
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}
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if (netdev->ieee80211_ptr) {
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dev = wiphy_to_dev(
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rdev = wiphy_to_dev(
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netdev->ieee80211_ptr->wiphy);
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filter_wiphy = dev->wiphy_idx;
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state->filter_wiphy = rdev->wiphy_idx;
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}
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dev_put(netdev);
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}
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return 0;
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}
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static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
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{
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int idx = 0, ret;
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struct nl80211_dump_wiphy_state *state = (void *)cb->args[0];
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struct cfg80211_registered_device *dev;
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rtnl_lock();
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if (!state) {
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state = kzalloc(sizeof(*state), GFP_KERNEL);
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if (!state)
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return -ENOMEM;
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state->filter_wiphy = -1;
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ret = nl80211_dump_wiphy_parse(skb, cb, state);
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if (ret) {
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kfree(state);
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rtnl_unlock();
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return ret;
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}
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cb->args[0] = (long)state;
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}
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kfree(tb);
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list_for_each_entry(dev, &cfg80211_rdev_list, list) {
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if (!net_eq(wiphy_net(&dev->wiphy), sock_net(skb->sk)))
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continue;
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if (++idx <= start)
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if (++idx <= state->start)
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continue;
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if (filter_wiphy != -1 && dev->wiphy_idx != filter_wiphy)
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if (state->filter_wiphy != -1 &&
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state->filter_wiphy != dev->wiphy_idx)
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continue;
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/* attempt to fit multiple wiphy data chunks into the skb */
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do {
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ret = nl80211_send_wiphy(dev, skb,
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NETLINK_CB(cb->skb).portid,
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cb->nlh->nlmsg_seq,
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NLM_F_MULTI,
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split, &cb->args[1],
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&cb->args[2],
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&cb->args[3]);
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NLM_F_MULTI, state);
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if (ret < 0) {
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/*
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* If sending the wiphy data didn't fit (ENOBUFS
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@ -1604,27 +1618,34 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
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idx--;
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break;
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}
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} while (cb->args[1] > 0);
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} while (state->split_start > 0);
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break;
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}
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rtnl_unlock();
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cb->args[0] = idx;
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state->start = idx;
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return skb->len;
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}
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static int nl80211_dump_wiphy_done(struct netlink_callback *cb)
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{
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kfree((void *)cb->args[0]);
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return 0;
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}
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static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info)
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{
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struct sk_buff *msg;
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struct cfg80211_registered_device *dev = info->user_ptr[0];
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struct nl80211_dump_wiphy_state state = {};
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msg = nlmsg_new(4096, GFP_KERNEL);
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if (!msg)
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return -ENOMEM;
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if (nl80211_send_wiphy(dev, msg, info->snd_portid, info->snd_seq, 0,
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false, NULL, NULL, NULL) < 0) {
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&state) < 0) {
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nlmsg_free(msg);
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return -ENOBUFS;
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}
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@ -8418,6 +8439,7 @@ static struct genl_ops nl80211_ops[] = {
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.cmd = NL80211_CMD_GET_WIPHY,
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.doit = nl80211_get_wiphy,
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.dumpit = nl80211_dump_wiphy,
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.done = nl80211_dump_wiphy_done,
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.policy = nl80211_policy,
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/* can be retrieved by unprivileged users */
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.internal_flags = NL80211_FLAG_NEED_WIPHY |
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@ -9038,13 +9060,13 @@ static struct genl_multicast_group nl80211_regulatory_mcgrp = {
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void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev)
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{
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struct sk_buff *msg;
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struct nl80211_dump_wiphy_state state = {};
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msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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if (!msg)
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return;
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if (nl80211_send_wiphy(rdev, msg, 0, 0, 0,
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false, NULL, NULL, NULL) < 0) {
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if (nl80211_send_wiphy(rdev, msg, 0, 0, 0, &state) < 0) {
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nlmsg_free(msg);
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return;
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}
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