2023-09-13 02:41:33

by Dmitry Antipov

Subject: [PATCH] [v2] wifi: wext: avoid extra calls to strlen() in ieee80211_bss()

Since 'sprintf()' returns the number of characters emitted, an
extra calls to 'strlen()' in 'ieee80211_bss()' may be dropped.

Signed-off-by: Dmitry Antipov <[email protected]>
---
v2: fix subject and reformat strings to avoid breaks (Johannes Berg)
---
net/wireless/scan.c | 47 ++++++++++++++++++++++++---------------------
1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 19516073c6d5..ae4d000009fe 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -3422,59 +3422,63 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
cfg = (u8 *)ie + 2;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
- sprintf(buf, "Mesh Network Path Selection Protocol ID: "
- "0x%02X", cfg[0]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Mesh Network Path Selection Protocol ID: 0x%02X",
+ cfg[0]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
- sprintf(buf, "Path Selection Metric ID: 0x%02X",
- cfg[1]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Path Selection Metric ID: 0x%02X",
+ cfg[1]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
- sprintf(buf, "Congestion Control Mode ID: 0x%02X",
- cfg[2]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Congestion Control Mode ID: 0x%02X",
+ cfg[2]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
- sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Synchronization ID: 0x%02X",
+ cfg[3]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
- sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Authentication ID: 0x%02X",
+ cfg[4]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
- sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Formation Info: 0x%02X",
+ cfg[5]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
- sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf,
+ "Capabilities: 0x%02X",
+ cfg[6]);
current_ev = iwe_stream_add_point_check(info,
current_ev,
end_buf,
@@ -3530,17 +3534,16 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,

memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
- sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf, "tsf=%016llx",
+ (unsigned long long)(ies->tsf));
current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
&iwe, buf);
if (IS_ERR(current_ev))
goto unlock;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
- sprintf(buf, " Last beacon: %ums ago",
- elapsed_jiffies_msecs(bss->ts));
- iwe.u.data.length = strlen(buf);
+ iwe.u.data.length = sprintf(buf, " Last beacon: %ums ago",
+ elapsed_jiffies_msecs(bss->ts));
current_ev = iwe_stream_add_point_check(info, current_ev,
end_buf, &iwe, buf);
if (IS_ERR(current_ev))
--
2.41.0