From: Changli Gao <xiaosuo@gmail.com>
To: Jan Engelhardt <jengelh@medozas.de>
Cc: netfilter-devel@vger.kernel.org, Changli Gao <xiaosuo@gmail.com>
Subject: [PATCH] xtables-addon: Remove recursive function calls
Date: Mon, 7 Mar 2011 16:14:29 +0800 [thread overview]
Message-ID: <1299485669-31288-1-git-send-email-xiaosuo@gmail.com> (raw)
The stack memory is very limited in Linux kernel.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
---
extensions/xt_geoip.c | 46 +++++++++++++++++++++++++++-------------------
1 file changed, 27 insertions(+), 19 deletions(-)
diff --git a/extensions/xt_geoip.c b/extensions/xt_geoip.c
index d644605..98f03e4 100644
--- a/extensions/xt_geoip.c
+++ b/extensions/xt_geoip.c
@@ -167,16 +167,20 @@ static bool geoip_bsearch6(const struct geoip_subnet6 *range,
{
int mid;
- if (hi <= lo)
- return false;
- mid = (lo + hi) / 2;
- if (ipv6_cmp(&range[mid].begin, addr) <= 0 &&
- ipv6_cmp(addr, &range[mid].end) <= 0)
- return true;
- if (ipv6_cmp(&range[mid].begin, addr) > 0)
- return geoip_bsearch6(range, addr, lo, mid);
- else if (ipv6_cmp(&range[mid].end, addr) < 0)
- return geoip_bsearch6(range, addr, mid + 1, hi);
+ while (1) {
+ if (hi <= lo)
+ return false;
+ mid = (lo + hi) / 2;
+ if (ipv6_cmp(&range[mid].begin, addr) <= 0 &&
+ ipv6_cmp(addr, &range[mid].end) <= 0)
+ return true;
+ if (ipv6_cmp(&range[mid].begin, addr) > 0)
+ hi = mid;
+ else if (ipv6_cmp(&range[mid].end, addr) < 0)
+ lo = mid + 1;
+ else
+ break;
+ }
WARN_ON(true);
return false;
@@ -218,15 +222,19 @@ static bool geoip_bsearch4(const struct geoip_subnet4 *range,
{
int mid;
- if (hi <= lo)
- return false;
- mid = (lo + hi) / 2;
- if (range[mid].begin <= addr && addr <= range[mid].end)
- return true;
- if (range[mid].begin > addr)
- return geoip_bsearch4(range, addr, lo, mid);
- else if (range[mid].end < addr)
- return geoip_bsearch4(range, addr, mid + 1, hi);
+ while (1) {
+ if (hi <= lo)
+ return false;
+ mid = (lo + hi) / 2;
+ if (range[mid].begin <= addr && addr <= range[mid].end)
+ return true;
+ if (range[mid].begin > addr)
+ hi = mid;
+ else if (range[mid].end < addr)
+ lo = mid + 1;
+ else
+ break;
+ }
WARN_ON(true);
return false;
next reply other threads:[~2011-03-07 8:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-07 8:14 Changli Gao [this message]
2011-04-14 7:07 ` [PATCH] xtables-addon: Remove recursive function calls Jan Engelhardt
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