From 86e8cf98de3e74bbfb0003501e0004bf1e5e2618 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 19 Jun 2013 10:57:22 +0200 Subject: [PATCH] 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 --- net/wireless/nl80211.c | 210 +++++++++++++++++++++++------------------ 1 file changed, 116 insertions(+), 94 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index f8ffb9a59c83..7dc3343427c1 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -1111,10 +1111,16 @@ nl80211_send_mgmt_stypes(struct sk_buff *msg, return 0; } +struct nl80211_dump_wiphy_state { + s64 filter_wiphy; + long start; + long split_start, band_start, chan_start; + bool split; +}; + static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, struct sk_buff *msg, u32 portid, u32 seq, - int flags, bool split, long *split_start, - long *band_start, long *chan_start) + int flags, struct nl80211_dump_wiphy_state *state) { void *hdr; struct nlattr *nl_bands, *nl_band; @@ -1125,19 +1131,14 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, int i; const struct ieee80211_txrx_stypes *mgmt_stypes = dev->wiphy.mgmt_stypes; - long start = 0, start_chan = 0, start_band = 0; u32 features; hdr = nl80211hdr_put(msg, portid, seq, flags, NL80211_CMD_NEW_WIPHY); if (!hdr) return -ENOBUFS; - /* allow always using the variables */ - if (!split) { - split_start = &start; - band_start = &start_band; - chan_start = &start_chan; - } + if (WARN_ON(!state)) + return -EINVAL; if (nla_put_u32(msg, NL80211_ATTR_WIPHY, dev->wiphy_idx) || nla_put_string(msg, NL80211_ATTR_WIPHY_NAME, @@ -1146,7 +1147,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, cfg80211_rdev_list_generation)) goto nla_put_failure; - switch (*split_start) { + switch (state->split_start) { case 0: if (nla_put_u8(msg, NL80211_ATTR_WIPHY_RETRY_SHORT, dev->wiphy.retry_short) || @@ -1192,8 +1193,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, nla_put_flag(msg, WIPHY_FLAG_SUPPORTS_5_10_MHZ)) goto nla_put_failure; - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; case 1: if (nla_put(msg, NL80211_ATTR_CIPHER_SUITES, @@ -1237,22 +1238,23 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, } } - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; case 2: if (nl80211_put_iftypes(msg, NL80211_ATTR_SUPPORTED_IFTYPES, dev->wiphy.interface_modes)) goto nla_put_failure; - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; case 3: nl_bands = nla_nest_start(msg, NL80211_ATTR_WIPHY_BANDS); if (!nl_bands) goto nla_put_failure; - for (band = *band_start; band < IEEE80211_NUM_BANDS; band++) { + for (band = state->band_start; + band < IEEE80211_NUM_BANDS; band++) { struct ieee80211_supported_band *sband; sband = dev->wiphy.bands[band]; @@ -1264,12 +1266,12 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, if (!nl_band) goto nla_put_failure; - switch (*chan_start) { + switch (state->chan_start) { case 0: if (nl80211_send_band_rateinfo(msg, sband)) goto nla_put_failure; - (*chan_start)++; - if (split) + state->chan_start++; + if (state->split) break; default: /* add frequencies */ @@ -1278,7 +1280,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, if (!nl_freqs) goto nla_put_failure; - for (i = *chan_start - 1; + for (i = state->chan_start - 1; i < sband->n_channels; i++) { nl_freq = nla_nest_start(msg, i); @@ -1287,26 +1289,27 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, chan = &sband->channels[i]; - if (nl80211_msg_put_channel(msg, chan, - split)) + if (nl80211_msg_put_channel( + msg, chan, + state->split)) goto nla_put_failure; nla_nest_end(msg, nl_freq); - if (split) + if (state->split) break; } if (i < sband->n_channels) - *chan_start = i + 2; + state->chan_start = i + 2; else - *chan_start = 0; + state->chan_start = 0; nla_nest_end(msg, nl_freqs); } nla_nest_end(msg, nl_band); - if (split) { + if (state->split) { /* start again here */ - if (*chan_start) + if (state->chan_start) band--; break; } @@ -1314,14 +1317,14 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, nla_nest_end(msg, nl_bands); if (band < IEEE80211_NUM_BANDS) - *band_start = band + 1; + state->band_start = band + 1; else - *band_start = 0; + state->band_start = 0; /* if bands & channels are done, continue outside */ - if (*band_start == 0 && *chan_start == 0) - (*split_start)++; - if (split) + if (state->band_start == 0 && state->chan_start == 0) + state->split_start++; + if (state->split) break; case 4: nl_cmds = nla_nest_start(msg, NL80211_ATTR_SUPPORTED_COMMANDS); @@ -1387,7 +1390,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, } CMD(start_p2p_device, START_P2P_DEVICE); CMD(set_mcast_rate, SET_MCAST_RATE); - if (split) { + if (state->split) { CMD(crit_proto_start, CRIT_PROTOCOL_START); CMD(crit_proto_stop, CRIT_PROTOCOL_STOP); } @@ -1411,8 +1414,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, } nla_nest_end(msg, nl_cmds); - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; case 5: if (dev->ops->remain_on_channel && @@ -1428,29 +1431,30 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, if (nl80211_send_mgmt_stypes(msg, mgmt_stypes)) goto nla_put_failure; - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; case 6: #ifdef CONFIG_PM - if (nl80211_send_wowlan(msg, dev, split)) + if (nl80211_send_wowlan(msg, dev, state->split)) goto nla_put_failure; - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; #else - (*split_start)++; + state->split_start++; #endif case 7: if (nl80211_put_iftypes(msg, NL80211_ATTR_SOFTWARE_IFTYPES, dev->wiphy.software_iftypes)) goto nla_put_failure; - if (nl80211_put_iface_combinations(&dev->wiphy, msg, split)) + if (nl80211_put_iface_combinations(&dev->wiphy, msg, + state->split)) goto nla_put_failure; - (*split_start)++; - if (split) + state->split_start++; + if (state->split) break; case 8: if ((dev->wiphy.flags & WIPHY_FLAG_HAVE_AP_SME) && @@ -1464,7 +1468,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, * dump is split, otherwise it makes it too big. Therefore * only advertise it in that case. */ - if (split) + if (state->split) features |= NL80211_FEATURE_ADVERTISE_CHAN_LIMITS; if (nla_put_u32(msg, NL80211_ATTR_FEATURE_FLAGS, features)) goto nla_put_failure; @@ -1491,7 +1495,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, * case we'll continue with more data in the next round, * but break unconditionally so unsplit data stops here. */ - (*split_start)++; + state->split_start++; break; case 9: if (dev->wiphy.extended_capabilities && @@ -1510,7 +1514,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, goto nla_put_failure; /* done */ - *split_start = 0; + state->split_start = 0; break; } return genlmsg_end(msg, hdr); @@ -1520,66 +1524,76 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, return -EMSGSIZE; } +static int nl80211_dump_wiphy_parse(struct sk_buff *skb, + struct netlink_callback *cb, + struct nl80211_dump_wiphy_state *state) +{ + struct nlattr **tb = nl80211_fam.attrbuf; + int ret = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize, + tb, nl80211_fam.maxattr, nl80211_policy); + /* ignore parse errors for backward compatibility */ + if (ret) + return 0; + + state->split = tb[NL80211_ATTR_SPLIT_WIPHY_DUMP]; + if (tb[NL80211_ATTR_WIPHY]) + state->filter_wiphy = nla_get_u32(tb[NL80211_ATTR_WIPHY]); + if (tb[NL80211_ATTR_WDEV]) + state->filter_wiphy = nla_get_u64(tb[NL80211_ATTR_WDEV]) >> 32; + if (tb[NL80211_ATTR_IFINDEX]) { + struct net_device *netdev; + struct cfg80211_registered_device *rdev; + int ifidx = nla_get_u32(tb[NL80211_ATTR_IFINDEX]); + + netdev = dev_get_by_index(sock_net(skb->sk), ifidx); + if (!netdev) + return -ENODEV; + if (netdev->ieee80211_ptr) { + rdev = wiphy_to_dev( + netdev->ieee80211_ptr->wiphy); + state->filter_wiphy = rdev->wiphy_idx; + } + dev_put(netdev); + } + + return 0; +} + static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb) { int idx = 0, ret; - int start = cb->args[0]; + struct nl80211_dump_wiphy_state *state = (void *)cb->args[0]; struct cfg80211_registered_device *dev; - s64 filter_wiphy = -1; - bool split = false; - struct nlattr **tb; - int res; - - /* will be zeroed in nlmsg_parse() */ - tb = kmalloc(sizeof(*tb) * (NL80211_ATTR_MAX + 1), GFP_KERNEL); - if (!tb) - return -ENOMEM; rtnl_lock(); - res = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize, - tb, NL80211_ATTR_MAX, nl80211_policy); - if (res == 0) { - split = tb[NL80211_ATTR_SPLIT_WIPHY_DUMP]; - if (tb[NL80211_ATTR_WIPHY]) - filter_wiphy = nla_get_u32(tb[NL80211_ATTR_WIPHY]); - if (tb[NL80211_ATTR_WDEV]) - filter_wiphy = nla_get_u64(tb[NL80211_ATTR_WDEV]) >> 32; - if (tb[NL80211_ATTR_IFINDEX]) { - struct net_device *netdev; - int ifidx = nla_get_u32(tb[NL80211_ATTR_IFINDEX]); - - netdev = dev_get_by_index(sock_net(skb->sk), ifidx); - if (!netdev) { - rtnl_unlock(); - kfree(tb); - return -ENODEV; - } - if (netdev->ieee80211_ptr) { - dev = wiphy_to_dev( - netdev->ieee80211_ptr->wiphy); - filter_wiphy = dev->wiphy_idx; - } - dev_put(netdev); + if (!state) { + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + state->filter_wiphy = -1; + ret = nl80211_dump_wiphy_parse(skb, cb, state); + if (ret) { + kfree(state); + rtnl_unlock(); + return ret; } + cb->args[0] = (long)state; } - kfree(tb); list_for_each_entry(dev, &cfg80211_rdev_list, list) { if (!net_eq(wiphy_net(&dev->wiphy), sock_net(skb->sk))) continue; - if (++idx <= start) + if (++idx <= state->start) continue; - if (filter_wiphy != -1 && dev->wiphy_idx != filter_wiphy) + if (state->filter_wiphy != -1 && + state->filter_wiphy != dev->wiphy_idx) continue; /* attempt to fit multiple wiphy data chunks into the skb */ do { ret = nl80211_send_wiphy(dev, skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, - NLM_F_MULTI, - split, &cb->args[1], - &cb->args[2], - &cb->args[3]); + NLM_F_MULTI, state); if (ret < 0) { /* * If sending the wiphy data didn't fit (ENOBUFS @@ -1604,27 +1618,34 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb) idx--; break; } - } while (cb->args[1] > 0); + } while (state->split_start > 0); break; } rtnl_unlock(); - cb->args[0] = idx; + state->start = idx; return skb->len; } +static int nl80211_dump_wiphy_done(struct netlink_callback *cb) +{ + kfree((void *)cb->args[0]); + return 0; +} + static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info) { struct sk_buff *msg; struct cfg80211_registered_device *dev = info->user_ptr[0]; + struct nl80211_dump_wiphy_state state = {}; msg = nlmsg_new(4096, GFP_KERNEL); if (!msg) return -ENOMEM; if (nl80211_send_wiphy(dev, msg, info->snd_portid, info->snd_seq, 0, - false, NULL, NULL, NULL) < 0) { + &state) < 0) { nlmsg_free(msg); return -ENOBUFS; } @@ -8418,6 +8439,7 @@ static struct genl_ops nl80211_ops[] = { .cmd = NL80211_CMD_GET_WIPHY, .doit = nl80211_get_wiphy, .dumpit = nl80211_dump_wiphy, + .done = nl80211_dump_wiphy_done, .policy = nl80211_policy, /* can be retrieved by unprivileged users */ .internal_flags = NL80211_FLAG_NEED_WIPHY | @@ -9038,13 +9060,13 @@ static struct genl_multicast_group nl80211_regulatory_mcgrp = { void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev) { struct sk_buff *msg; + struct nl80211_dump_wiphy_state state = {}; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) return; - if (nl80211_send_wiphy(rdev, msg, 0, 0, 0, - false, NULL, NULL, NULL) < 0) { + if (nl80211_send_wiphy(rdev, msg, 0, 0, 0, &state) < 0) { nlmsg_free(msg); return; } -- 2.39.5