ubase

suckless linux base utils
git clone git://git.2f30.org/ubase.git
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commit 0a3ed68d2500c2989545b3bf0af5ebc0b50bec7a
parent 5322e83da0f32f1d6805a2c3f492cfd3c178d489
Author: sin <sin@2f30.org>
Date:   Mon Jun  2 14:00:55 +0100

Add initial implementation of login(1)

No shadow support atm.

Diffstat:
Makefile | 1+
login.c | 109+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 110 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile @@ -32,6 +32,7 @@ SRC = \ id.c \ insmod.c \ killall5.c \ + login.c \ lsmod.c \ lsusb.c \ mknod.c \ diff --git a/login.c b/login.c @@ -0,0 +1,109 @@ +/* See LICENSE file for copyright and license details. */ +#define _XOPEN_SOURCE +#include <errno.h> +#include <grp.h> +#include <pwd.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <unistd.h> +#include "config.h" +#include "util.h" + +static int dologin(struct passwd *, int); + +static void +usage(void) +{ + eprintf("usage: %s [-p] username\n", argv0); +} + +int +main(int argc, char *argv[]) +{ + struct passwd *pw; + uid_t uid; + gid_t gid; + char *pass, *cryptpass; + int pflag = 0; + + ARGBEGIN { + case 'p': + pflag = 1; + break; + default: + usage(); + } ARGEND; + + if (argc < 1) + usage(); + + errno = 0; + pw = getpwnam(argv[0]); + if (errno) + eprintf("getpwnam: %s:", argv[0]); + else if (!pw) + eprintf("who are you?\n"); + + switch (pw->pw_passwd[0]) { + case '!': + case '*': + eprintf("Denied\n"); + } + + if (pw->pw_passwd[0] == 'x' && pw->pw_passwd[1] == '\0') + eprintf("no shadow support\n"); + + uid = pw->pw_uid; + gid = pw->pw_gid; + + /* Empty password? Login now */ + if (pw->pw_passwd[0] == '\0') + goto login; + + /* Flush pending input */ + ioctl(STDIN_FILENO, TCFLSH, (void *)0); + + pass = getpass("Password: "); + if (!pass) + eprintf("getpass:"); + putchar('\n'); + cryptpass = crypt(pass, pw->pw_passwd); + explicit_bzero(pass, strlen(pass)); + if (!cryptpass) + eprintf("crypt:"); + if (strcmp(cryptpass, pw->pw_passwd) != 0) + eprintf("oops\n"); + +login: + if (initgroups(argv[0], gid) < 0) + eprintf("initgroups:"); + if (setgid(gid) < 0) + eprintf("setgid:"); + if (setuid(uid) < 0) + eprintf("setuid:"); + + return dologin(pw, pflag); +} + +static int +dologin(struct passwd *pw, int preserve) +{ + char *shell[] = { pw->pw_shell, pw->pw_shell, "-l", NULL }; + + if (preserve == 0) + 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("PATH", strcmp(pw->pw_name, "root") == 0 ? + ENV_SUPATH : ENV_PATH, 1); + if (chdir(pw->pw_dir) < 0) + eprintf("chdir %s:", pw->pw_dir); + execvp(shell[0], shell + 1); + weprintf("execvp %s:", shell[0]); + return (errno == ENOENT) ? 127 : 126; +}