[U-Boot] [RFC PATCH v2 3/5] lib/net_utils.c: make string_to_ip stricter

[Chris Packham <judge.packham@gmail.com>]

From: Chris Packham <chris.packham@alliedtelesis.co.nz>

Previously values greater than 255 were implicitly truncated. Add some
stricter checking to reject addresses with components >255.

With the input "1234192.168.1.1" the old behaviour would truncate the
address to 192.168.1.1. New behaviour rejects the string outright and
returns 0, which for the purposes of IP addresses can be considered an
error.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
Changes in v2: None

 lib/net_utils.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/net_utils.c b/lib/net_utils.c
index b425a68..2b20ccb 100644
--- a/lib/net_utils.c
+++ b/lib/net_utils.c
@@ -39,8 +39,9 @@ IPaddr_t string_to_ip(const char *s)
 
 	for (addr=0, i=0; i<4; ++i) {
 		ulong val = s ? simple_strtoul(s, &e, 10) : 0;
+		if (val > 255)
+			return 0;
 		addr <<= 8;
-		addr |= (val & 0xFF);
 		if (s) {
 			s = (*e) ? e+1 : e;
 		}
-- 
1.7.12.rc2.16.g034161a