From: Simon Horman <horms@verge.net.au>
Date: Tue, 12 Feb 2013 01:45:53 +0000 (+0900)
Subject: MEDIUM: server: Tighten up parsing of weight string
X-Git-Tag: v1.5-dev18~94
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b796afa60dc44e96beeec508e6180f3ed1708b72;p=thirdparty%2Fhaproxy.git

MEDIUM: server: Tighten up parsing of weight string

Detect:
* Empty weight string, including no digits before '%' in relative
  weight string
* Trailing garbage, including between the last integer and '%'
  in relative weights

The motivation for this is to allow the weight string to be safely
logged if successfully parsed by this function

Signed-off-by: Simon Horman <horms@verge.net.au>
---

diff --git a/src/server.c b/src/server.c
index 4c1762f425..98a9fbe9c7 100644
--- a/src/server.c
+++ b/src/server.c
@@ -164,7 +164,8 @@ const char *server_parse_weight_change_request(struct server *sv,
 					       const char *weight_str)
 {
 	struct proxy *px;
-	int w;
+	long int w;
+	char *end;
 
 	px = sv->proxy;
 
@@ -174,8 +175,10 @@ const char *server_parse_weight_change_request(struct server *sv,
 	if (!*weight_str)
 		return "Require <weight> or <weight%>.\n";
 
-	w = atoi(weight_str);
-	if (strchr(weight_str, '%') != NULL) {
+	w = strtol(weight_str, &end, 10);
+	if (end == weight_str)
+		return "Empty weight string empty or preceded by garbage";
+	else if (end[0] == '%' && end[1] == '\0') {
 		if (w < 0)
 			return "Relative weight must be positive.\n";
 		/* Avoid integer overflow */
@@ -187,6 +190,8 @@ const char *server_parse_weight_change_request(struct server *sv,
 	}
 	else if (w < 0 || w > 256)
 		return "Absolute weight can only be between 0 and 256 inclusive.\n";
+	else if (end[0] != '\0')
+		return "Trailing garbage in weight string";
 
 	if (w && w != sv->iweight && !(px->lbprm.algo & BE_LB_PROP_DYN))
 		return "Backend is using a static LB algorithm and only accepts weights '0%' and '100%'.\n";