1 files changed, 95 insertions, 0 deletions
diff --git a/check/check.c b/check/check.c
new file mode 100644
index 0000000..a776053
--- /dev/null
+++ b/check/check.c
@@ -0,0 +1,95 @@
+#define _POSIX_C_SOURCE 200809L
+#include <errno.h>
+#include <grp.h>
+#include <locale.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pwd.h>
+#include <unistd.h>
+
+#include "check.h"
+
+static char *progname = NULL;
+
+void fatal(int include_errno, char *fmt, ...)
+{
+	fprintf(stderr, "%s: ", progname);
+	va_list ap;
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	if (include_errno) {
+		fprintf(stderr, ": %s", strerror(errno));
+	}
+	fputc('\n', stderr);
+	exit(EXIT_FAILURE);
+}
+
+static int authorize(const char *user)
+{
+	(void)user;
+	return 1;
+}
+
+static char *get_username(void)
+{
+	struct passwd *pwd = getpwuid(getuid());
+	if (pwd == NULL) {
+		fatal(1, "unable to determine user name");
+	}
+	printf("checking for user %s\n", pwd->pw_name);
+	return pwd->pw_name;
+}
+
+static char *get_groupname(void)
+{
+	struct group *grp = getgrgid(getgid());
+	if (grp == NULL) {
+		fatal(1, "unable to determine group name");
+	}
+	printf("checking for group %s\n", grp->gr_name);
+	return grp->gr_name;
+}
+
+static char *get_command(int argc, char *argv[])
+{
+	if (argc < 2) {
+		fatal(1, "missing operands");
+	}
+
+	printf("checking command %s\n", argv[1]);
+	return argv[1];
+}
+
+int main(int argc, char *argv[])
+{
+	setlocale(LC_ALL, "");
+	progname = argv[0];
+
+	char *cmd = get_command(argc, argv);
+	char *user = get_username();
+	char *group = get_groupname();
+
+	switch (get_permission(user, group, cmd)) {
+	case NEED_AUTH:
+		if (authorize(user) != 0) {
+			fatal(0, "bad authorization");
+		}
+		/* FALLTHRU */
+	case NO_AUTH:
+		puts("granted");
+		return 0;
+
+	case DENIED:
+		fatal(0, "explicitly denied");
+		return 1;
+	
+	case UNKNOWN:
+	default:
+		fatal(0, "denied by default");
+	}
+
+	return 1;
+}