[hackers] [ubase] Simplify dologin() in su(1) || sin

From: <git_AT_suckless.org>
Date: Tue, 03 Jun 2014 13:28:54 +0200

commit b8dbf05ce7aee91e1cf646840f7cc7a8c7827ba9
Author: sin <sin_AT_2f30.org>
Date: Tue Jun 3 12:24:17 2014 +0100

    Simplify dologin() in su(1)
    
    Exec the user's shell with -l to fake a login.

diff --git a/su.c b/su.c
index f5ac7d9..2f7eace 100644
--- a/su.c
+++ b/su.c
_AT_@ -16,7 +16,6 @@
 extern char **environ;
 
 static const char *randreply(void);
-static char *msetenv(const char *, const char *);
 static void dologin(struct passwd *);
 
 static void
_AT_@ -161,39 +160,21 @@ randreply(void)
         return replies[rand() % LEN(replies)];
 }
 
-static char *
-msetenv(const char *name, const char *value)
-{
- char *buf;
- size_t sz;
-
- sz = strlen(name) + strlen(value) + 2;
- buf = emalloc(sz);
- snprintf(buf, sz, "%s=%s", name, value);
- return buf;
-}
-
 static void
 dologin(struct passwd *pw)
 {
- char shbuf[strlen(pw->pw_shell) + 1];
- char * const *newargv;
- char * const *newenv;
-
- strcpy(shbuf, pw->pw_shell);
- newargv = (char *const[]){shbuf, NULL};
- newenv = (char *const[]){
- msetenv("HOME", pw->pw_dir),
- msetenv("SHELL", pw->pw_shell),
- msetenv("USER", pw->pw_name),
- msetenv("LOGNAME", pw->pw_name),
- msetenv("TERM", getenv("TERM")),
- msetenv("PATH",
- strcmp(pw->pw_name, "root") == 0 ?
- ENV_SUPATH : ENV_PATH),
- NULL
- };
+ char *term = getenv("TERM");
+ clearenv();
+ setenv("HOME", pw->pw_dir, 1);
+ setenv("SHELL", pw->pw_shell, 1);
+ setenv("USER", pw->pw_name, 1);
+ setenv("LOGNAME", pw->pw_name, 1);
+ setenv("TERM", term ? term : "vt100", 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);
- execve(pw->pw_shell, newargv, newenv);
+ execlp(pw->pw_shell, pw->pw_shell, "-l", NULL);
 }
Received on Tue Jun 03 2014 - 13:28:54 CEST