From 9f8fcdcf96aff9c872189b081d62b1a061579b20 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 3 Jul 2026 13:54:37 +1000 Subject: conf: Clean up conf_ip4_prefix() 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 Signed-off-by: Stefano Brivio --- conf.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/conf.c b/conf.c index 32163f5..ea299e1 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; -- cgit v1.2.3