More defer-ization

net.c

@@ -57,32 +57,33 @@ bool netInitNsFromParent(struct nsjconf_t * nsjconf, int pid)
 		return true;
 	}
 
-	struct nl_sock *sk;
-	struct nl_cache *link_cache;
 	int err, master_index;
-	bool ret = false;
 
-	sk = nl_socket_alloc();
+	struct nl_sock *sk = nl_socket_alloc();
+	defer(nl_socket_free(sk));
+
 	if ((err = nl_connect(sk, NETLINK_ROUTE)) < 0) {
 		LOG_E("Unable to connect socket: %s", nl_geterror(err));
-		goto out_sock;
+		return false;
 	}
 
-	struct rtnl_link *rmv = rtnl_link_macvlan_alloc();
-
+	__block struct rtnl_link *rmv = rtnl_link_macvlan_alloc();
 	if (rmv == NULL) {
 		LOG_E("rtnl_link_macvlan_alloc(): %s", nl_geterror(err));
-		goto out_sock;
+		return false;
 	}
+	rtnl_link_put(rmv);
 
+	_block struct nl_cache *link_cache;
 	if ((err = rtnl_link_alloc_cache(sk, AF_UNSPEC, &link_cache)) < 0) {
 		LOG_E("rtnl_link_alloc_cache(): %s", nl_geterror(err));
-		goto out_link;
+		return false;
 	}
+	defer(nl_cache_free(link_cache));
 
 	if (!(master_index = rtnl_link_name2i(link_cache, nsjconf->iface))) {
 		LOG_E("rtnl_link_name2i(): Did not find '%s' interface", nsjconf->iface);
-		goto out_cache;
+		return false;
 	}
 
 	rtnl_link_set_name(rmv, IFACE_NAME);
@@ -91,17 +92,10 @@ bool netInitNsFromParent(struct nsjconf_t * nsjconf, int pid)
 
 	if ((err = rtnl_link_add(sk, rmv, NLM_F_CREATE)) < 0) {
 		LOG_E("rtnl_link_add(): %s", nl_geterror(err));
-		goto out_cache;
+		return false;
 	}
 
-	ret = true;
- out_cache:
-	nl_cache_free(link_cache);
- out_link:
-	rtnl_link_put(rmv);
- out_sock:
-	nl_socket_free(sk);
-	return ret;
+	return true;
 }
 #else				// defined(NSJAIL_NL3_WITH_MACVLAN)
 static bool netSystemSbinIp(struct nsjconf_t *nsjconf, char *const *argv)

subproc.c

@@ -247,6 +247,8 @@ void subprocRunChild(struct nsjconf_t *nsjconf, int fd_in, int fd_out, int fd_er
 		PLOG_E("socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC) failed");
 		return;
 	}
+	__block int subproc_sock = sv[1];
+	defer(close(subproc_sock));
 
 	pid_t pid = syscall(__NR_clone, (uintptr_t) flags, NULL, NULL, NULL, (uintptr_t) 0);
 	if (pid == 0) {
@@ -259,13 +261,11 @@ void subprocRunChild(struct nsjconf_t *nsjconf, int fd_in, int fd_out, int fd_er
 		       "doesn't support CLONE_NEWUSER. Alternatively, you might want to recompile your "
 		       "kernel with support for namespaces or check the setting of the "
 		       "kernel.unprivileged_userns_clone sysctl", flags);
-		close(sv[1]);
 		return;
 	}
 	subprocAdd(nsjconf, pid, fd_in);
 
 	if (subprocInitParent(nsjconf, pid, sv[1]) == false) {
-		close(sv[1]);
 		return;
 	}
 
@@ -279,5 +279,4 @@ void subprocRunChild(struct nsjconf_t *nsjconf, int fd_in, int fd_out, int fd_er
 		log_buf[sz] = '\0';
 		logDirectlyToFD(log_buf);
 	}
-	close(sv[1]);
 }

util.c

@@ -82,14 +82,13 @@ bool utilWriteBufToFile(char *filename, const void *buf, size_t len, int open_fl
 		PLOG_E("Couldn't open '%s' for R/O", filename);
 		return false;
 	}
+	defer(close(fd));
 
 	if (utilWriteToFd(fd, buf, len) == false) {
 		PLOG_E("Couldn't write '%zu' bytes to file '%s' (fd='%d')", len, filename, fd);
-		close(fd);
 		unlink(filename);
 		return false;
 	}
-	close(fd);
 
 	LOG_D("Written '%zu' bytes to '%s'", len, filename);