net: return bool with iptable_has_criu_jump_target

To improve readability, this patch changes the return type of
iptables_has_criu_jump_target() to a boolean, where 'true' indicates
that iptables has CRIU jump target and 'false' indicates otherwise.

Suggested-by: Pavel Tikhomirov <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>

criu/net.c

@@ -3190,7 +3190,7 @@ static inline int nftables_network_unlock(void)
 #endif
 }
 
-static int iptables_has_criu_jump_target(void)
+static bool iptables_has_criu_jump_target(void)
 {
  int fd, ret;
  char *argv[4] = { "sh", "-c", "iptables -C INPUT -j CRIU", NULL };
@@ -3203,7 +3203,7 @@ static int iptables_has_criu_jump_target(void)
 
  ret = cr_system(fd, fd, fd, "sh", argv, CRS_CAN_FAIL);
  close_safe(&fd);
- return ret;
+ return !ret;
 }
 
 static int iptables_network_unlock_internal(void)
@@ -3228,7 +3228,7 @@ static int iptables_network_unlock_internal(void)
  /* For compatibility with iptables-nft backend, we need to make sure that all jump
  * targets have been removed before deleting the CRIU chain.
  */
- if (!iptables_has_criu_jump_target()) {
+ if (iptables_has_criu_jump_target()) {
  ret |= iptables_restore(false, delete_jump_targets, sizeof(delete_jump_targets) - 1);
  if (kdat.ipv6)
  ret |= iptables_restore(true, delete_jump_targets, sizeof(delete_jump_targets) - 1);