lxc-start to report exit code of started application

src/lxc/error.c

@@ -23,7 +23,11 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/wait.h>
 #include "error.h"
+#include "log.h"
+
+lxc_log_define(lxc_error, lxc);
 
 static const char *const catalogue[] = {
 
@@ -67,3 +71,32 @@ const char *const lxc_strerror(int error)
 
 	return catalogue[error];
 }
+
+/*---------------------------------------------------------------------------*/
+/* lxc_error_set_and_log
+ * function is here to convert
+ * the reported status to an exit code as detailed here:
+ *
+ *   0-126       exit code of the application
+ *   128+n       signal n received by the application
+ *   255         lxc error
+ */
+extern int  lxc_error_set_and_log(int pid, int status)
+{
+	int ret = 0;
+
+	if (WIFEXITED(status)) {
+		ret = WEXITSTATUS(status);
+		if (ret)
+			INFO("child <%d> ended on error (%d)", pid, ret);
+	}
+
+	if (WIFSIGNALED(status)) {
+		int signal = WTERMSIG(status);
+		ret = ret + 128 + signal;
+
+		INFO("child <%d> ended on signal (%d)", pid, signal);
+	}
+
+	return ret;
+}

src/lxc/error.h

@@ -59,4 +59,5 @@ typedef enum {
 	LXC_LAST_ERROR,
 } lxc_error_t;
 
+extern int  lxc_error_set_and_log(int pid, int status);
 #endif

src/lxc/lxc_start.c

@@ -61,7 +61,7 @@ Options :\n\
 int main(int argc, char *argv[])
 {
 	char *const *args;
-	int err;
+	int err = -1;
 	struct termios tios;
 
 	char *const default_args[] = {
@@ -69,9 +69,8 @@ int main(int argc, char *argv[])
 		'\0',
 	};
 
-	err = lxc_arguments_parse(&my_args, argc, argv);
-	if (err)
-		return 1;
+	if (lxc_arguments_parse(&my_args, argc, argv))
+		return err;
 
 	if (!my_args.argc)
 		args = default_args; 
@@ -80,19 +79,15 @@ int main(int argc, char *argv[])
 
 	if (lxc_log_init(my_args.log_file, my_args.log_priority,
 			 my_args.progname, my_args.quiet))
-		return 1;
+		return err;
 
 	if (tcgetattr(0, &tios)) {
 		ERROR("failed to get current terminal settings : %s",
 		      strerror(errno));
-		return 1;
+		return err;
 	}
 
 	err = lxc_start(my_args.name, args);
-	if (err) {
-		ERROR("failed to start '%s'", my_args.name);
-		err = 1;
-	}
 
 	if (tcsetattr(0, TCSAFLUSH, &tios))
 		ERROR("failed to restore terminal settings : %s",

src/lxc/start.c

@@ -439,7 +439,7 @@ int lxc_spawn(const char *name, struct lxc_handler *handler, char *const argv[])
 
 		if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) {
 			SYSERROR("failed to set sigprocmask");
-			return -1;
+			goto out_child;
 		}
 
 		close(sv[1]);
@@ -460,12 +460,9 @@ int lxc_spawn(const char *name, struct lxc_handler *handler, char *const argv[])
 		}
 
 		/* Setup the container, ip, names, utsname, ... */
-		err = lxc_setup(name, handler->tty, &handler->tty_info);
-		if (err) {
+		if (lxc_setup(name, handler->tty, &handler->tty_info)) {
 			ERROR("failed to setup the container");
-			if (write(sv[0], &err, sizeof(err)) < 0)
-				SYSERROR("failed to write the socket");
-			goto out_child;
+			goto out_warn_father;
 		}
 
 		if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) {
@@ -476,11 +473,10 @@ int lxc_spawn(const char *name, struct lxc_handler *handler, char *const argv[])
 		execvp(argv[0], argv);
 		SYSERROR("failed to exec %s", argv[0]);
 
-		err = LXC_ERROR_WRONG_COMMAND;
+	out_warn_father:
 		/* If the exec fails, tell that to our father */
 		if (write(sv[0], &err, sizeof(err)) < 0)
 			SYSERROR("failed to write the socket");
-		
 	out_child:
 		exit(err);
 	}
@@ -509,8 +505,7 @@ int lxc_spawn(const char *name, struct lxc_handler *handler, char *const argv[])
 	}
 
 	/* Wait for the child to exec or returning an error */
-	err = read(sv[1], &sync, sizeof(sync));
-	if (err < 0) {
+	if (read(sv[1], &sync, sizeof(sync)) < 0) {
 		ERROR("failed to read the socket");
 		goto out_abort;
 	}
@@ -542,7 +537,7 @@ out_abort:
 int lxc_start(const char *name, char *const argv[])
 {
 	struct lxc_handler handler = { 0 };
-	int err = -LXC_ERROR_INTERNAL;
+	int err = -1;
 	int status;
 
 	if (lxc_init(name, &handler)) {
@@ -556,14 +551,16 @@ int lxc_start(const char *name, char *const argv[])
 		goto out;
 	}
 
-	if (lxc_poll(name, &handler)) {
+	err = lxc_poll(name, &handler);
+	if (err) {
 		ERROR("mainloop exited with an error");
 		goto out_abort;
 	}
 
 	while (waitpid(handler.pid, &status, 0) < 0 && errno == EINTR)
 		continue;
-	err = 0;
+
+	err =  lxc_error_set_and_log(handler.pid, status);
 out:
 	lxc_fini(name, &handler);
 	return err;