rune/libenclave: Fix processing LD_LIBRARY_PATH #2

Instead of inheriting LD_LIBRARY_PATH by bootstrap, make it available
only for boostrap's child process.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>

rune/libcontainer/container_linux.go

@@ -531,16 +531,12 @@ func (c *linuxContainer) commandTemplate(p *Process, childInitPipe *os.File, chi
 				fmt.Sprintf("_LIBCONTAINER_AGENTPIPE=%d", stdioFdCount+len(cmd.ExtraFiles)-1))
 		}
 
+		if c.config.Enclave.Path != "" {
+			cmd.Env = append(cmd.Env, "_LIBCONTAINER_PAL_PATH="+string(c.config.Enclave.Path))
+		}
+
 		if c.config.Enclave.Signer != "server" {
-			rootfs := c.config.Rootfs
-			// LD_LIBRARY_PATH must be set before the process starts to be valid
-			cmd.Env = append(cmd.Env,
-				fmt.Sprintf("LD_LIBRARY_PATH=%s/usr/lib:%s/usr/lib64:%s/lib:%s/lib64",
-					rootfs, rootfs, rootfs, rootfs));
-			cmd.Env = append(cmd.Env,
-				fmt.Sprintf("_LIBCONTAINER_PAL_PATH=%s/%s", rootfs, c.config.Enclave.Path))
-		} else if c.config.Enclave.Path != "" {
-			cmd.Env = append(cmd.Env, "_LIBCONTAINER_PAL_PATH=" + c.config.Enclave.Path)
+			cmd.Env = append(cmd.Env, "_LIBCONTAINER_PAL_ROOTFS="+string(c.config.Rootfs))
 		}
 
 		if detached {

rune/libcontainer/nsenter/loader.c

@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <dlfcn.h>
+#include <linux/limits.h>
 
 /* Defined in nsexec.c. */
 
@@ -37,18 +38,28 @@ int is_enclave(void)
 
 int load_enclave_runtime(void)
 {
-	const char *file;
+	char pal_full_path[PATH_MAX+1];
+	char *pal_path;
+	const char *rootfs;
 	void *dl;
 
-	file = getenv("_LIBCONTAINER_PAL_PATH");
-	if (file == NULL || *file == '\0') {
+	pal_path = getenv("_LIBCONTAINER_PAL_PATH");
+	if (pal_path == NULL || *pal_path == '\0') {
 		write_log(DEBUG, "invalid environment _LIBCONTAINER_PAL_PATH");
 		return 0;
 	}
-	write_log(DEBUG, "_LIBCONTAINER_PAL_PATH = %s", file);
+
+	write_log(DEBUG, "_LIBCONTAINER_PAL_PATH = %s", pal_path);
 	write_log(DEBUG, "LD_LIBRARY_PATH = %s", getenv("LD_LIBRARY_PATH"));
 
-	dl = dlopen(file, RTLD_NOW);
+	rootfs = getenv("_LIBCONTAINER_PAL_ROOTFS");
+	if (rootfs && *rootfs != '\0') {
+		snprintf(pal_full_path, sizeof(pal_full_path) - 1, "%s/%s", rootfs, pal_path);
+		pal_path = pal_full_path;
+	}
+
+	dl = dlopen(pal_path, RTLD_NOW);
+	unsetenv("LD_LIBRARY_PATH");
 	if (dl == NULL) {
 		write_log(DEBUG, "dlopen(): %s", dlerror());
 		/* set errno correctly, make bail() work better */

rune/libcontainer/nsenter/nsexec.c

@@ -579,6 +579,7 @@ void nsexec(void)
 	jmp_buf env;
 	int sync_child_pipe[2], sync_grandchild_pipe[2];
 	struct nlconfig_t config = { 0 };
+	char *rootfs;
 
 	/*
 	 * Setup a pipe to send logs to the parent. This should happen
@@ -643,6 +644,16 @@ void nsexec(void)
 
 	/* TODO: Currently we aren't dealing with child deaths properly. */
 
+	rootfs = getenv("_LIBCONTAINER_PAL_ROOTFS");
+	if (rootfs && *rootfs != '\0') {
+		char ld_path[PATH_MAX+1];
+
+		snprintf(ld_path, sizeof(ld_path) - 1,
+			 "%s/usr/lib/x86_64-linux-gnu:%s/usr/lib:%s/usr/lib64:%s/lib:%s/lib64",
+			 rootfs, rootfs, rootfs, rootfs, rootfs);
+		setenv("LD_LIBRARY_PATH", ld_path, 1);
+	}
+
 	/*
 	 * Okay, so this is quite annoying.
 	 *
@@ -702,15 +713,10 @@ void nsexec(void)
 			int len;
 			pid_t child, first_child = -1;
 			bool ready = false;
-			int ret;
 
 			/* For debugging. */
 			prctl(PR_SET_NAME, (unsigned long)"runc:[0:PARENT]", 0, 0, 0);
 
-			ret = load_enclave_runtime();
-			if (ret < 0)
-				bail("load_enclave_runtime() failed, ret = %d", ret);
-
 			/* Start the process of getting a container. */
 			child = clone_parent(&env, JUMP_CHILD);
 			if (child < 0)
@@ -837,6 +843,11 @@ void nsexec(void)
 	case JUMP_CHILD:{
 			pid_t child;
 			enum sync_t s;
+			int ret;
+
+			ret = load_enclave_runtime();
+			if (ret < 0)
+				bail("load_enclave_runtime() failed, ret = %d", ret);
 
 			/* We're in a child and thus need to tell the parent if we die. */
 			syncfd = sync_child_pipe[0];