From: Stephen Hemminger <stephen@networkplumber.org>
Date: Wed, 6 Feb 2019 18:49:47 +0000 (-0800)
Subject: tc: avoid problems with hard coded rate string length
X-Git-Tag: v5.0.0~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=817204d0b0ee98b0849902e5b20cc3e84460b900;p=thirdparty%2Fiproute2.git

tc: avoid problems with hard coded rate string length

The parse_percent_rate function assumed the buffer was 20 characters.
Better to pass length in case the size ever changes.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---

diff --git a/tc/tc_util.c b/tc/tc_util.c
index 1377b536e..4e289ae9c 100644
--- a/tc/tc_util.c
+++ b/tc/tc_util.c
@@ -190,7 +190,8 @@ static const struct rate_suffix {
 	{ NULL }
 };
 
-static int parse_percent_rate(char *rate, const char *str, const char *dev)
+static int parse_percent_rate(char *rate, size_t len,
+			      const char *str, const char *dev)
 {
 	long dev_mbit;
 	int ret;
@@ -221,8 +222,8 @@ static int parse_percent_rate(char *rate, const char *str, const char *dev)
 
 	rate_mbit = perc * dev_mbit;
 
-	ret = snprintf(rate, 20, "%lf", rate_mbit);
-	if (ret <= 0 || ret >= 20) {
+	ret = snprintf(rate, len, "%lf", rate_mbit);
+	if (ret <= 0 || ret >= len) {
 		fprintf(stderr, "Unable to parse calculated rate\n");
 		return -1;
 	}
@@ -239,7 +240,7 @@ int get_percent_rate(unsigned int *rate, const char *str, const char *dev)
 {
 	char r_str[20];
 
-	if (parse_percent_rate(r_str, str, dev))
+	if (parse_percent_rate(r_str, sizeof(r_str), str, dev))
 		return -1;
 
 	return get_rate(rate, r_str);
@@ -249,7 +250,7 @@ int get_percent_rate64(__u64 *rate, const char *str, const char *dev)
 {
 	char r_str[20];
 
-	if (parse_percent_rate(r_str, str, dev))
+	if (parse_percent_rate(r_str, sizeof(r_str), str, dev))
 		return -1;
 
 	return get_rate64(rate, r_str);