[hackers] [ubase][PATCH 1/4] su: simplify logic

[neeshy]

Inline dologin, and simplify common code
---
 su.c | 69 ++++++++++++++++++++++++------------------------------------
 1 file changed, 28 insertions(+), 41 deletions(-)

diff --git a/su.c b/su.c
index 329238f..bc7a94f 100644
--- a/su.c
+++ b/su.c
@@ -18,28 +18,6 @@ extern char **environ;
 static int lflag = 0;
 static int pflag = 0;
 
-static int
-dologin(struct passwd *pw)
-{
-       char *shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
-       char *term = getenv("TERM");
-       clearenv();
-       setenv("HOME", pw->pw_dir, 1);
-       setenv("SHELL", shell, 1);
-       setenv("USER", pw->pw_name, 1);
-       setenv("LOGNAME", pw->pw_name, 1);
-       setenv("TERM", term ? term : "linux", 1);
-       if (strcmp(pw->pw_name, "root") == 0)
-               setenv("PATH", ENV_SUPATH, 1);
-       else
-               setenv("PATH", ENV_PATH, 1);
-       if (chdir(pw->pw_dir) < 0)
-               eprintf("chdir %s:", pw->pw_dir);
-       execlp(shell, shell, "-l", NULL);
-       weprintf("execlp %s:", shell);
-       return (errno == ENOENT) ? 127 : 126;
-}
-
 static void
 usage(void)
 {
@@ -50,9 +28,9 @@ int
 main(int argc, char *argv[])
 {
        char *usr = "root", *pass;
-       char *shell;
+       char *shell, *term;
        struct passwd *pw;
-       char *newargv[2];
+       char *newargv[3];
        uid_t uid;
 
        ARGBEGIN {
@@ -66,11 +44,9 @@ main(int argc, char *argv[])
                usage();
        } ARGEND;
 
-       if (argc < 1)
-               ;
-       else if (argc == 1)
+       if (argc == 1)
                usr = argv[0];
-       else
+       else if (argc > 1)
                usage();
 
        errno = 0;
@@ -98,13 +74,26 @@ main(int argc, char *argv[])
        if (setuid(pw->pw_uid) < 0)
                eprintf("setuid:");
 
+       shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
        if (lflag) {
-               return dologin(pw);
+               newargv[0] = shell;
+               newargv[1] = "-l";
+               newargv[2] = NULL;
+               term = getenv("TERM");
+               clearenv();
+               setenv("HOME", pw->pw_dir, 1);
+               setenv("SHELL", shell, 1);
+               setenv("USER", pw->pw_name, 1);
+               setenv("LOGNAME", pw->pw_name, 1);
+               setenv("TERM", term ? term : "linux", 1);
+               if (chdir(pw->pw_dir) < 0)
+                       eprintf("chdir %s:", pw->pw_dir);
        } else {
-               shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
                newargv[0] = shell;
                newargv[1] = NULL;
-               if (!pflag) {
+               if (pflag) {
+                       shell = getenv("SHELL");
+               } else {
                        setenv("HOME", pw->pw_dir, 1);
                        setenv("SHELL", shell, 1);
                        if (strcmp(pw->pw_name, "root") != 0) {
@@ -112,14 +101,12 @@ main(int argc, char *argv[])
                                setenv("LOGNAME", pw->pw_name, 1);
                        }
                }
-               if (strcmp(pw->pw_name, "root") == 0)
-                       setenv("PATH", ENV_SUPATH, 1);
-               else
-                       setenv("PATH", ENV_PATH, 1);
-               execve(pflag ? getenv("SHELL") : shell,
-                      newargv, environ);
-               weprintf("execve %s:", shell);
-               return (errno == ENOENT) ? 127 : 126;
        }
-       return 0;
-}
\ No newline at end of file
+       if (strcmp(pw->pw_name, "root") == 0)
+               setenv("PATH", ENV_SUPATH, 1);
+       else
+               setenv("PATH", ENV_PATH, 1);
+       execve(shell, newargv, environ);
+       weprintf("execve %s:", shell);
+       return (errno == ENOENT) ? 127 : 126;
+}
-- 
2.43.1