[hackers] [utmp] Launch a login shell || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Wed, 17 Sep 2014 10:02:17 +0200

commit 4a855c000f1d300a44c784ed88d78a11d41cdca7
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
Date: Fri Aug 29 20:08:22 2014 +0200

    Launch a login shell
    
    Since we are creating a utmp entry, it is logical to create a login
    shell

diff --git a/utmp.c b/utmp.c
index f551f9d..75c35f5 100644
--- a/utmp.c
+++ b/utmp.c
_AT_@ -38,8 +38,10 @@ int
 main(int argc, char *argv[])
 {
         int status;
+ size_t len;
         uid_t uid;
         sigset_t set;
+ char *p, argv0[FILENAME_MAX], *sh;
         extern void addutmp(void), delutmp(void);
 
         egid = getegid();
_AT_@ -59,15 +61,23 @@ main(int argc, char *argv[])
         setenv("SHELL", pw->pw_shell, 1);
         setenv("HOME", pw->pw_dir, 1);
 
+ if ((p = strrchr(pw->pw_shell, '/')) == NULL)
+ die("incorrect shell field of passwd");
+ if ((len = strlen(++p)) > sizeof(argv0) - 2)
+ die("shell name too long");
+ argv0[0] = '-';
+ memcpy(&argv0[1], p, len);
+
         sigfillset(&set);
         sigprocmask(SIG_BLOCK, &set, NULL);
 
         switch (fork()) {
         case 0:
                 sigprocmask(SIG_UNBLOCK, &set, NULL);
- argv[0] = getenv("SHELL");
- execv(argv[0], argv);
- die("error executing shell:%s", strerror(errno));
+ sh = pw->pw_shell;
+ argv[0] = argv0;
+ execv(sh, argv);
+ die("error executing shell(%s):%s", sh, strerror(errno));
         case -1:
                 die("error spawning child:%s", strerror(errno));
         default:
Received on Wed Sep 17 2014 - 10:02:17 CEST