Add atoid() function to convert a string to an id_t (uid, gid or

pid).  We have to be careful to choose() either strtol() or strtoul()
depending on whether the string appears to be signed or unsigned.
Always using strtoul() is unsafe on 64-bit platforms since the
uid might be represented as a negative number and (unsigned long)-1
on a 64-bit system is 0xffffffffffffffff not 0xffffffff.
Fixes a problem with uids larger than 0x7fffffff on 32-bit platforms.

diff --git a/plugins/sudoers/atoid.c b/plugins/sudoers/atoid.c
new file mode 100644 (file)
index 0000000..bd5aa1e
--- /dev/null
+++ b/plugins/sudoers/atoid.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2013 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+
+#include <stdio.h>
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif /* STDC_HEADERS */
+#if defined(HAVE_STDINT_H)
+# include <stdint.h>
+#elif defined(HAVE_INTTYPES_H)
+# include <inttypes.h>
+#endif
+#include <errno.h>
+#include <limits.h>
+
+#define DEFAULT_TEXT_DOMAIN    "sudoers"
+#include "gettext.h"
+
+#include "missing.h"
+#include "sudo_debug.h"
+
+id_t
+atoid(const char *p, const char **errstr)
+{
+    char *ep;
+    id_t rval = 0;
+    debug_decl(atoid, SUDO_DEBUG_UTIL)
+
+    errno = 0;
+    if (*p == '-') {
+       long lval = strtol(p, &ep, 10);
+       if (ep == p || *ep != '\0') {
+           *errstr = N_("invalid value");
+           errno = EINVAL;
+           goto done;
+       }
+       if ((errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN)) ||
+           (lval > INT_MAX || lval < INT_MIN)) {
+           errno = ERANGE;
+           *errstr = N_("value out of range");
+           goto done;
+       }
+       rval = (id_t)lval;
+       *errstr = NULL;
+    } else {
+       unsigned long ulval = strtoul(p, &ep, 10);
+       if (ep == p || *ep != '\0') {
+           *errstr = N_("invalid value");
+           errno = EINVAL;
+           goto done;
+       }
+       if ((errno == ERANGE && ulval == ULONG_MAX) || ulval > UINT_MAX) {
+           errno = ERANGE;
+           *errstr = N_("value too large");
+           goto done;
+       }
+       rval = (id_t)ulval;
+       *errstr = NULL;
+    }
+done:
+    debug_return_int(rval);
+}