126 lines
2.4 KiB
C
126 lines
2.4 KiB
C
/* See LICENSE file for copyright and license details. */
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#include <sys/types.h>
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#include <errno.h>
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#include <grp.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "config.h"
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#include "passwd.h"
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#include "util.h"
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extern char **environ;
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static int dologin(struct passwd *);
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static void
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usage(void)
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{
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eprintf("usage: %s [-lp] [username]\n", argv0);
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}
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static int lflag = 0;
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static int pflag = 0;
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int
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main(int argc, char *argv[])
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{
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char *usr = "root", *pass;
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char *shell;
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struct passwd *pw;
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char *newargv[2];
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uid_t uid;
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ARGBEGIN {
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case 'l':
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lflag = 1;
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break;
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case 'p':
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pflag = 1;
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break;
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default:
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usage();
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} ARGEND;
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if (argc < 1)
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;
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else if (argc == 1)
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usr = argv[0];
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else
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usage();
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errno = 0;
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pw = getpwnam(usr);
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if (errno)
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eprintf("getpwnam: %s:", usr);
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else if (!pw)
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eprintf("who are you?\n");
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uid = getuid();
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if (uid) {
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pass = getpass("Password: "); putchar('\n');
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if (!pass)
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eprintf("getpass:");
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if (pw_check(pw, pass) <= 0)
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exit(EXIT_FAILURE);
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}
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if (initgroups(usr, pw->pw_gid) < 0)
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eprintf("initgroups:");
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if (setgid(pw->pw_gid) < 0)
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eprintf("setgid:");
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if (setuid(pw->pw_uid) < 0)
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eprintf("setuid:");
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if (lflag) {
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return dologin(pw);
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} else {
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shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
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newargv[0] = shell;
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newargv[1] = NULL;
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if (!pflag) {
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setenv("HOME", pw->pw_dir, 1);
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setenv("SHELL", shell, 1);
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if (strcmp(pw->pw_name, "root") != 0) {
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setenv("USER", pw->pw_name, 1);
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setenv("LOGNAME", pw->pw_name, 1);
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}
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}
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if (strcmp(pw->pw_name, "root") == 0)
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setenv("PATH", ENV_SUPATH, 1);
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else
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setenv("PATH", ENV_PATH, 1);
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execve(pflag ? getenv("SHELL") : shell,
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newargv, environ);
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weprintf("execve %s:", shell);
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return (errno == ENOENT) ? 127 : 126;
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}
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return EXIT_SUCCESS;
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}
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static int
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dologin(struct passwd *pw)
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{
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char *shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
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char *term = getenv("TERM");
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clearenv();
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setenv("HOME", pw->pw_dir, 1);
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setenv("SHELL", shell, 1);
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setenv("USER", pw->pw_name, 1);
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setenv("LOGNAME", pw->pw_name, 1);
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setenv("TERM", term ? term : "linux", 1);
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if (strcmp(pw->pw_name, "root") == 0)
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setenv("PATH", ENV_SUPATH, 1);
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else
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setenv("PATH", ENV_PATH, 1);
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if (chdir(pw->pw_dir) < 0)
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eprintf("chdir %s:", pw->pw_dir);
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execlp(shell, shell, "-l", NULL);
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weprintf("execlp %s:", shell);
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return (errno == ENOENT) ? 127 : 126;
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}
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