Merge pull request #188 from laijs/check-result

check the return value of the functions declared with warn_unused_result

src/container.c

@@ -313,15 +313,22 @@ static int container_setup_mount(struct hyper_container *container)
 		return -1;
 	}
 
-	if (unlink("./dev/ptmx") < 0)
+	if (unlink("./dev/ptmx") < 0) {
 		perror("remove /dev/ptmx failed");
-	if (symlink("/dev/pts/ptmx", "./dev/ptmx") < 0)
+		return -1;
+	}
+	if (symlink("/dev/pts/ptmx", "./dev/ptmx") < 0) {
 		perror("link /dev/pts/ptmx to /dev/ptmx failed");
+		return -1;
+	}
 
-	symlink("/proc/self/fd", "./dev/fd");
-	symlink("/proc/self/fd/0", "./dev/stdin");
-	symlink("/proc/self/fd/1", "./dev/stdout");
-	symlink("/proc/self/fd/2", "./dev/stderr");
+	if (symlink("/proc/self/fd", "./dev/fd") < 0 ||
+	    symlink("/proc/self/fd/0", "./dev/stdin") < 0 ||
+	    symlink("/proc/self/fd/1", "./dev/stdout") < 0 ||
+	    symlink("/proc/self/fd/2", "./dev/stderr") < 0) {
+		perror("failed to symlink for /dev/fd, /dev/stdin, /dev/stdout or /dev/stderr");
+		return -1;
+	}
 
 	return 0;
 }
@@ -584,7 +591,10 @@ static int hyper_setup_container_rootfs(void *data)
 		perror("failed to bind rootfs");
 		goto fail;
 	}
-	chdir(rootfs);
+	if (chdir(rootfs) < 0) {
+		perror("failed to change the root to path of the container root(before manipulating)");
+		goto fail;
+	}
 
 	/*
 	 * Recreate dns resolver iif configured by pod spec. Other cases
@@ -621,9 +631,15 @@ static int hyper_setup_container_rootfs(void *data)
 	}
 	/* pivot_root won't work, see
 	 * Documention/filesystem/ramfs-rootfs-initramfs.txt */
-	chroot(".");
+	if (chroot(".") < 0) {
+		perror("failed to setup the root for the mount namepsace");
+		goto fail;
+	}
 
-	chdir("/");
+	if (chdir("/") < 0) {
+		perror("failed chdir to the new root");
+		goto fail;
+	}
 
 	if (container_setup_sysctl(container) < 0) {
 		fprintf(stderr, "container sets up sysctl failed\n");

src/exec.c

@@ -271,7 +271,10 @@ static int hyper_setup_exec_user(struct hyper_exec *exec)
 	if (exec->tty) {
 		char ptmx[512];
 		sprintf(ptmx, "/dev/pts/%d", exec->ptyno);
-		chown(ptmx, uid, gid);
+		if (chown(ptmx, uid, gid) < 0) {
+			perror("failed to change the owner for the slave pty file");
+			goto fail;
+		}
 	}
 
 	// apply
@@ -490,7 +493,10 @@ static int hyper_do_exec_cmd(struct hyper_exec *exec, struct hyper_pod *pod, int
 		perror("fail to enter container ns");
 		goto out;
 	}
-	chdir("/");
+	if (chdir("/") < 0) {
+		perror("fail to change to the root of the rootfs");
+		goto out;
+	}
 
 	/* TODO: merge container env to exec env in hyperd */
 	if (hyper_setup_env(c->exec.envs, c->exec.envs_num) < 0) {

src/init.c

@@ -1370,13 +1370,20 @@ int main(int argc, char *argv[])
 		return -1;
 	}
 
-	symlink("/busybox", "/sh");
-	symlink("/busybox", "/tar");
-	symlink("/busybox", "/sbin/modprobe");
-	symlink("/busybox", "/sbin/depmod");
-	symlink("/iptables", "/sbin/iptables");
-	symlink("/iptables", "/sbin/iptables-restore");
-	symlink("/iptables", "/sbin/iptables-save");
+	if (symlink("/busybox", "/sh") < 0 ||
+	    symlink("/busybox", "/tar") < 0 ||
+	    symlink("/busybox", "/sbin/modprobe") < 0 ||
+	    symlink("/busybox", "/sbin/depmod") < 0) {
+		perror("failed to symlink tools to /busybox");
+		return -1;
+	}
+
+	if (symlink("/iptables", "/sbin/iptables") < 0 ||
+	    symlink("/iptables", "/sbin/iptables-restore") < 0 ||
+	    symlink("/iptables", "/sbin/iptables-save") < 0) {
+		perror("failed to symlink tools to /iptables");
+		/* TODO disable portmapping */
+	}
 
 	cmdline = read_cmdline();