From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755759AbcBVVYh (ORCPT ); Mon, 22 Feb 2016 16:24:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40732 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755550AbcBVVYg (ORCPT ); Mon, 22 Feb 2016 16:24:36 -0500 From: Jessica Yu To: Andrew Morton Cc: Rasmus Villemoes , Andy Shevchenko , Kees Cook , linux-kernel@vger.kernel.org, Jessica Yu Subject: [PATCH v2] sscanf: implement basic character sets Date: Mon, 22 Feb 2016 16:24:19 -0500 Message-Id: <1456176259-32643-1-git-send-email-jeyu@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 22 Feb 2016 21:24:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Implement basic character sets for the '%[]' conversion specifier. The '%[]' conversion specifier matches a nonempty sequence of characters from the specified set of accepted (or with '^', rejected) characters between the brackets. The substring matched is to be made up of characters in (or not in) the set. This implementation differs from its glibc counterpart in that it does not support character ranges (e.g., 'a-z' or '0-9'), the hyphen '-' is *not* a special character, and the brackets themselves cannot be matched. Signed-off-by: Jessica Yu --- Patch based on linux-next-20160222. v2: - Use kstrndup() to copy the character set from fmt instead of using a statically allocated array lib/vsprintf.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 525c8e1..93a6f52 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2714,6 +2714,45 @@ int vsscanf(const char *buf, const char *fmt, va_list args) num++; } continue; + case '[': + { + char *s = (char *)va_arg(args, char *); + char *set; + size_t (*op)(const char *str, const char *set); + size_t len = 0; + bool negate = (*(fmt) == '^'); + + if (field_width == -1) + field_width = SHRT_MAX; + + op = negate ? &strcspn : &strspn; + if (negate) + fmt++; + + len = strcspn(fmt, "]"); + /* invalid format; stop here */ + if (!len) + return num; + + set = kstrndup(fmt, len, GFP_KERNEL); + if (!set) + return num; + + /* advance fmt past ']' */ + fmt += len + 1; + + len = (*op)(str, set); + /* no matches */ + if (!len) + return num; + + while (*str && len-- && field_width--) + *s++ = *str++; + *s = '\0'; + kfree(set); + num++; + } + continue; case 'o': base = 8; break; -- 2.4.3