Commit Graph

7 Commits

Author SHA1 Message Date
glebius
f03db98338 Avoid OOB reads in memmem(3).
commit 51bdcdc424bd7169c8cccdc2de7cad17f5ea0f70
Author: Alexander Monakov <amonakov@ispras.ru>
Date:   Fri Jun 30 00:35:33 2017 +0300

    fix OOB reads in Xbyte_memmem

    Reported by Leah Neukirchen.

Reviewed by:	emaste
Approved by:	re (kib)
2018-10-15 20:20:57 +00:00
pfg
9014a6e40c libc: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-25 17:12:48 +00:00
emaste
77ef67ae70 libc: add reference to two-way algorithm and bad shift table in memmem/strstr
Requested by:	ed
2017-03-18 00:53:24 +00:00
emaste
76661c1ce5 libc: Use musl's O(n) memmem and strstr
It is O(n) in the length of the haystack (big) string, and has special
cases for short needle (little) strings, of one to four bytes, to avoid
excessive overhead.

There are a small set of nearly trivial cases where the startup overhead
of the musl implementation makes it slightly slower -- for example, a 31
byte needle that matches the beginning of the haystack.  It's faster for
non-trivial cases, and significantly so for inputs that trigger worst-
case behaviour of the previous implementation.  As an example, in my
tests a 16K needle that matches the end of a 64K haystack is nearly
2000x faster with this implementation.

Reviewed by:	bapt (earlier), ed (earlier)
Obtained from:	musl (snapshot at commit c718f9fc)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D2601
2017-03-18 00:51:39 +00:00
emaste
d45a21328b memmem(3): empty little string matches the beginning of the big string
This function originated in glibc, and this matches their behaviour
(and NetBSD, OpenBSD, and musl).

An empty big string (arg "l") is handled by the existing
l_len < s_len test.

Reviewed by:	bapt, ngie
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D2657
2015-05-26 21:16:07 +00:00
danger
ff17de3853 - ANSIfy function definitions
- use nul when we are looking for a terminating character where appropriate

Approved by:	imp
2009-02-03 17:58:20 +00:00
andre
45fd598f49 Add the function memmem(3) as found in glibc and others.
It is the binary equivalent to strstr(3).

 void *memmem(const void *big, size_t big_len,
	const void *little, size_t little_len);

Submitted by:	Pascal Gloor <pascal.gloor at spale.com>
MFC after:	3 days
2005-08-25 18:26:58 +00:00