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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 2013-06-19 10:57:22 +02:00
parent f93beba705
commit 86e8cf98de
1 changed files with 116 additions and 94 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

210
net/wireless/nl80211.c
View File

@ -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;
}