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 4c1762f..98a9fbe 100644
--- a/src/server.c
+++ b/src/server.c
@@ -164,7 +164,8 @@
const char *weight_str)
{
struct proxy *px;
- int w;
+ long int w;
+ char *end;
px = sv->proxy;
@@ -174,8 +175,10 @@
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 @@
}
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";