1 files changed, 97 insertions, 0 deletions
diff --git a/toys/lsb/su.c b/toys/lsb/su.c
new file mode 100644
index 00000000..52d20244
--- /dev/null
+++ b/toys/lsb/su.c
@@ -0,0 +1,97 @@
+/* su.c - switch user
+ *
+ * Copyright 2013 CE Strake <strake888@gmail.com>
+ *
+ * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/su.html
+ * TODO: log su attempts
+
+USE_SU(NEWTOY(su, "lmpc:s:", TOYFLAG_BIN|TOYFLAG_ROOTONLY))
+
+config SU
+  bool "su"
+  default y
+  help
+    usage: su [-lmp] [-c CMD] [-s SHELL] [USER [ARGS...]]
+
+    Switch to user (or root) and run shell (with optional command line).
+
+    -s	shell to use
+    -c	command to pass to shell with -c
+    -l	login shell
+    -(m|p)	preserve environment
+*/
+
+#define FOR_su
+#include "toys.h"
+
+GLOBALS(
+  char *s;
+  char *c;
+)
+
+static char *snapshot_env(char *name)
+{
+  char *s = getenv(name);
+
+  if (s) return xmsprintf("%s=%s", name, s);
+
+  return 0;
+}
+
+void su_main()
+{
+  char *name, *passhash = 0, **argu, **argv;
+  struct passwd *up;
+  struct spwd *shp;
+
+  if (*toys.optargs && !strcmp("-", *toys.optargs)) {
+    toys.optflags |= FLAG_l;
+    toys.optargs++;
+  }
+
+  if (*toys.optargs) name = *(toys.optargs++);
+  else name = "root";
+
+  if (!(shp = getspnam(name))) perror_exit("no '%s'", name);
+  if (*shp->sp_pwdp != '$') goto deny;
+  if (read_password(toybuf, sizeof(toybuf), "Password: ")) goto deny;
+  passhash = crypt(toybuf, shp->sp_pwdp);
+  memset(toybuf, 0, sizeof(toybuf));
+  if (!passhash || strcmp(passhash, shp->sp_pwdp)) goto deny;
+
+  up = xgetpwnam(name);
+  xsetuid(up->pw_uid);
+
+  argv = argu = xmalloc(sizeof(char *)*(toys.optc + 4));
+  *(argv++) = TT.s ? TT.s : up->pw_shell;
+
+  if (toys.optflags & FLAG_l) {
+    int i;
+    char *stuff[] = {snapshot_env("TERM"), snapshot_env("DISPLAY"),
+      snapshot_env("COLORTERM"), snapshot_env("XAUTHORITY")};
+
+    clearenv();
+    for (i=0; i < sizeof(stuff)/sizeof(char *); i++) putenv(stuff[i]);
+    *(argv++) = "-l";
+    xchdir(up->pw_dir);
+  } else unsetenv("IFS");
+  setenv("PATH", "/sbin:/bin:/usr/sbin:/usr/bin", 1);
+  if (!(toys.optflags & (FLAG_m|FLAG_p))) {
+    setenv("HOME", up->pw_dir, 1);
+    setenv("SHELL", up->pw_shell, 1);
+    setenv("USER", up->pw_name, 1);
+    setenv("LOGNAME", up->pw_name, 1);
+  } else unsetenv("IFS");
+
+  if (toys.optflags & FLAG_c) {
+    *(argv++) = "-c";
+    *(argv++) = TT.c;
+  }
+  while ((*(argv++) = *(toys.optargs++)));
+  xexec(argu);
+  perror_exit("can't exec %s", *argu);
+
+deny:
+  puts("No.");
+  toys.exitval = 1;
+}