sudo: cache success

apps/sudo.c

@@ -17,10 +17,16 @@
 #include <termios.h>
 #include <errno.h>
 #include <pwd.h>
-#include <sys/wait.h>
+#include <dirent.h>
 #include <sys/utsname.h>
+#include <sys/stat.h>
+#include <sys/time.h>
 #include <toaru/auth.h>
 
+#define MINUTES * 60
+
+#define SUDO_TIME 5 MINUTES
+
 uint32_t child = 0;
 
 void usage(int argc, char * argv[]) {
@@ -36,9 +42,20 @@ int main(int argc, char ** argv) {
 		return 1;
 	}
 
+	struct stat buf;
+	if (stat("/var/sudoers", &buf)) {
+		mkdir("/var/sudoers", 0700);
+	}
+
 	while (1) {
+		int need_password = 1;
+		int need_sudoers  = 1;
+
 		uid_t me = getuid();
-		if (me == 0) goto _do_it;
+		if (me == 0) {
+			need_password = 0;
+			need_sudoers  = 0;
+		}
 
 		struct passwd * p = getpwuid(me);
 		if (!p) {
@@ -46,8 +63,22 @@ int main(int argc, char ** argv) {
 			return 1;
 		}
 		char * username = p->pw_name;
-		char * password = malloc(sizeof(char) * 1024);
 
+		char token_file[64];
+		sprintf(token_file, "/var/sudoers/%d", me); /* TODO: Restrict to this session? */
+
+		if (need_password) {
+			struct stat buf;
+			if (!stat(token_file, &buf)) {
+				/* check the time */
+				if (buf.st_mtime > (SUDO_TIME) && time(NULL) - buf.st_mtime < (SUDO_TIME)) {
+					need_password = 0;
+				}
+			}
+		}
+
+		if (need_password) {
+			char * password = malloc(sizeof(char) * 1024);
 			fprintf(stderr, "[%s] password for %s: ", argv[0], username);
 			fflush(stderr);
 
@@ -74,8 +105,10 @@ int main(int argc, char ** argv) {
 				fprintf(stderr, "Sorry, try again.\n");
 				continue;
 			}
+		}
 
 		/* Determine if this user is in the sudoers file */
+		if (need_sudoers) {
 			FILE * sudoers = fopen("/etc/sudoers","r");
 			if (!sudoers) {
 				fprintf(stderr, "%s: /etc/sudoers is not available\n", argv[0]);
@@ -102,8 +135,15 @@ int main(int argc, char ** argv) {
 				fprintf(stderr, "%s is not in sudoers file.\n", username);
 				return 1;
 			}
+		}
+
+		/* Write a timestamp file */
+		FILE * f = fopen(token_file, "a");
+		if (!f) {
+			fprintf(stderr, "%s: (warning) failed to create token file\n", argv[0]);
+		}
+		fclose(f);
 
-_do_it:
 		/* Set username to root */
 		putenv("USER=root");