sandbox: change interface to make it easier to pass thru

The sandbox command line is passed to a shell for execution.  This can
be a bit awkward to quote right if you weren't expecting it, and even
if you were.  Change the default behavior to be more like `env` where
the arguments, as they are, get passed through and run.  If people want
the old shell behavior, they can use the -c option akin to `bash -c`.

Bug: https://bugs.gentoo.org/265907
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

3 files changed, 35 insertions, 20 deletions

diff --git a/src/options.c b/src/options.c
index 03cffda..64cd750 100644
--- a/src/options.c
+++ b/src/options.c
@@ -20,6 +20,7 @@ int opt_use_ns_sysv = -1;
 int opt_use_ns_time = -1;
 int opt_use_ns_user = -1;
 int opt_use_ns_uts = -1;
+bool opt_use_bash = false;
 
 static const struct {
 	const char *name;
@@ -76,7 +77,7 @@ static void show_version(void)
 	exit(0);
 }
 
-#define PARSE_FLAGS "+hV"
+#define PARSE_FLAGS "+chV"
 #define a_argument required_argument
 static struct option const long_opts[] = {
 	{"ns-on",         no_argument, &opt_use_namespaces, true},
@@ -99,6 +100,7 @@ static struct option const long_opts[] = {
 	{"ns-user-off",   no_argument, &opt_use_ns_user, false},
 	{"ns-uts-on",     no_argument, &opt_use_ns_uts, true},
 	{"ns-uts-off",    no_argument, &opt_use_ns_uts, false},
+	{"bash",          no_argument, NULL, 'c'},
 	{"help",          no_argument, NULL, 'h'},
 	{"version",       no_argument, NULL, 'V'},
 	{"run-configure", no_argument, NULL, 0x800},
@@ -125,6 +127,7 @@ static const char * const opts_help[] = {
 	"Disable the use of user namespaces",
 	"Enable  the use of UTS (hostname/uname) namespaces",
 	"Disable the use of UTS (hostname/uname) namespaces",
+	"Run command through bash shell",
 	"Print this help and exit",
 	"Print version and exit",
 	"Run local sandbox configure in same way and exit (developer only)",
@@ -201,6 +204,9 @@ void parseargs(int argc, char *argv[])
 
 	while ((i = getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
 		switch (i) {
+		case 'c':
+			opt_use_bash = true;
+			break;
 		case 'V':
 			show_version();
 		case 'h':
diff --git a/src/sandbox.c b/src/sandbox.c
index 7e8a769..7d6b03f 100644
--- a/src/sandbox.c
+++ b/src/sandbox.c
@@ -175,7 +175,9 @@ static int spawn_shell(char *argv_bash[], char **env, int debug)
 
 	/* Child's process */
 	if (0 == child_pid) {
-		int ret = execve(argv_bash[0], argv_bash, env);
+		/* Would be nice if execvpe were in POSIX. */
+		environ = env;
+		int ret = execvp(argv_bash[0], argv_bash);
 		sb_pwarn("failed to exec child");
 		_exit(ret);
 	} else if (child_pid < 0) {
@@ -258,25 +260,31 @@ int main(int argc, char **argv)
 		goto oom_error;
 
 	/* Setup bash argv */
-	str_list_add_item_copy(argv_bash, "/bin/bash", oom_error);
-	str_list_add_item_copy(argv_bash, "-rcfile", oom_error);
-	str_list_add_item_copy(argv_bash, sandbox_info.sandbox_rc, oom_error);
-	if (argc >= 2) {
-		int i;
-		size_t cmdlen;
-		char *cmd = NULL;
-
-		str_list_add_item_copy(argv_bash, run_str, oom_error);
-		str_list_add_item_copy(argv_bash, argv[1], oom_error);
-		cmdlen = strlen(argv_bash[4]);
-		for (i = 2; i < argc; i++) {
-			size_t arglen = strlen(argv[i]);
-			argv_bash[4] = xrealloc(argv_bash[4], cmdlen + arglen + 2);
-			argv_bash[4][cmdlen] = ' ';
-			memcpy(argv_bash[4] + cmdlen + 1, argv[i], arglen);
-			cmdlen += arglen + 1;
-			argv_bash[4][cmdlen] = '\0';
+	if (opt_use_bash || argc == 1) {
+		str_list_add_item_copy(argv_bash, "/bin/bash", oom_error);
+		str_list_add_item_copy(argv_bash, "-rcfile", oom_error);
+		str_list_add_item_copy(argv_bash, sandbox_info.sandbox_rc, oom_error);
+		if (argc >= 2) {
+			int i;
+			size_t cmdlen;
+			char *cmd = NULL;
+
+			str_list_add_item_copy(argv_bash, run_str, oom_error);
+			str_list_add_item_copy(argv_bash, argv[1], oom_error);
+			cmdlen = strlen(argv_bash[4]);
+			for (i = 2; i < argc; i++) {
+				size_t arglen = strlen(argv[i]);
+				argv_bash[4] = xrealloc(argv_bash[4], cmdlen + arglen + 2);
+				argv_bash[4][cmdlen] = ' ';
+				memcpy(argv_bash[4] + cmdlen + 1, argv[i], arglen);
+				cmdlen += arglen + 1;
+				argv_bash[4][cmdlen] = '\0';
+			}
 		}
+	} else {
+		int i;
+		for (i = 1; i < argc; ++i)
+			str_list_add_item_copy(argv_bash, argv[i], oom_error);
 	}
 
 #ifdef HAVE_PRCTL
diff --git a/src/sandbox.h b/src/sandbox.h
index 7e5b575..cdc1b9e 100644
--- a/src/sandbox.h
+++ b/src/sandbox.h
@@ -52,5 +52,6 @@ extern int opt_use_ns_sysv;
 extern int opt_use_ns_time;
 extern int opt_use_ns_user;
 extern int opt_use_ns_uts;
+extern bool opt_use_bash;
 
 #endif