Restructure conf_ip4_prefix() so that success is the early exit path and
failure is the "default" path. Also move the error handling (die()) into
it from the caller.
This saves a handful of lines for now, and will make integration with
upcoming parsing changes nicer.
Signed-off-by: David Gibson
---
conf.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)
diff --git a/conf.c b/conf.c
index 32163f56..ea299e18 100644
--- a/conf.c
+++ b/conf.c
@@ -350,9 +350,9 @@ static void conf_pasta_ns(int *netns_only, char *userns, char *netns,
/** conf_ip4_prefix() - Parse an IPv4 prefix length or netmask
* @arg: Netmask in dotted decimal or prefix length
*
- * Return: validated prefix length on success, -1 on failure
+ * Return: validated prefix length; dies on bad argument
*/
-static int conf_ip4_prefix(const char *arg)
+static uint8_t conf_ip4_prefix(const char *arg)
{
struct in_addr mask;
unsigned long len;
@@ -360,16 +360,16 @@ static int conf_ip4_prefix(const char *arg)
if (inet_pton(AF_INET, arg, &mask)) {
in_addr_t hmask = ntohl(mask.s_addr);
len = __builtin_popcount(hmask);
- if ((hmask << len) != 0)
- return -1;
+ if ((hmask << len) == 0)
+ return len;
} else {
errno = 0;
len = strtoul(arg, NULL, 0);
- if (len > 32 || errno)
- return -1;
+ if (!errno && len <= 32)
+ return len;
}
- return len;
+ die("Invalid prefix length: %s", arg);
}
/**
@@ -1606,20 +1606,13 @@ void conf(struct ctx *c, int argc, char **argv)
}
break;
}
- case 'n': {
- int plen;
-
+ case 'n':
if (addr_has_prefix_len)
die("Redundant prefix length specification");
- plen = conf_ip4_prefix(optarg);
- if (plen < 0)
- die("Invalid prefix length: %s", optarg);
-
- prefix_len_from_opt = plen + 96;
- c->ip4.prefix_len = plen;
+ c->ip4.prefix_len = conf_ip4_prefix(optarg);
+ prefix_len_from_opt = c->ip4.prefix_len + 96;
break;
- }
case 'M':
parse_mac(c->our_tap_mac, optarg);
break;
--
2.55.0