adding memmem fallback implementation proposal.

must be a rare occurence nowadays tough.

Author: devnexen

configure.ac

@@ -686,7 +686,7 @@ if test "$ac_cv_func_getaddrinfo" = yes; then
   AC_DEFINE(HAVE_GETADDRINFO,1,[Define if you have the getaddrinfo function])
 fi
 
-AC_REPLACE_FUNCS(strlcat strlcpy explicit_bzero getopt)
+AC_REPLACE_FUNCS(strlcat strlcpy explicit_bzero getopt memmem)
 AC_FUNC_ALLOCA
 PHP_TIME_R_TYPE
 PHP_CHECK_IN_ADDR_T
@@ -1612,7 +1612,7 @@ PHP_ADD_SOURCES(main, main.c snprintf.c spprintf.c \
        fopen_wrappers.c alloca.c  php_scandir.c \
        php_ini.c SAPI.c rfc1867.c php_content_types.c strlcpy.c \
        strlcat.c explicit_bzero.c reentrancy.c php_variables.c php_ticks.c \
-       network.c php_open_temporary_file.c \
+       network.c php_open_temporary_file.c memmem.c \
        output.c getopt.c php_syslog.c, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
 
 PHP_ADD_SOURCES_X(main, fastcgi.c, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1, PHP_FASTCGI_OBJS, no)

main/memmem.c

@@ -0,0 +1,48 @@
+/*
+  +----------------------------------------------------------------------+
+  | Copyright (c) The PHP Group                                          |
+  +----------------------------------------------------------------------+
+  | This source file is subject to version 3.01 of the PHP license,      |
+  | that is bundled with this package in the file LICENSE, and is        |
+  | available through the world-wide-web at the following url:           |
+  | https://www.php.net/license/3_01.txt                                 |
+  | If you did not receive a copy of the PHP license and are unable to   |
+  | obtain it through the world-wide-web, please send a note to          |
+  | license@php.net so we can mail you a copy immediately.               |
+  +----------------------------------------------------------------------+
+  | Author:                                                              |
+  +----------------------------------------------------------------------+
+*/
+
+#include "php.h"
+
+#ifndef HAVE_MEMMEM
+
+#include <string.h>
+
+void* memmem(const void *haystack, size_t hlen, const void *needle, size_t nlen)
+{
+    const char *shaystack = (const char *)haystack;
+    const char *sneedle = (const char *)needle;
+    const char *s, *end;
+
+    // handful of optimisation cases before doing any heavy lifting
+    if (!hlen)
+        return (void *)haystack;
+    else if (hlen == 1)
+        return memchr(haystack, *sneedle, hlen);
+    else if (hlen < nlen)
+        return NULL;
+
+    s = shaystack;
+    end = s + hlen - nlen;
+
+    while (s <= end) {
+        if (memcmp(s, sneedle, nlen) == 0)
+            return (void *)s;
+        ++s;
+    }
+
+    return NULL;
+}
+#endif

main/php.h

@@ -179,6 +179,12 @@ END_EXTERN_C()
 #define explicit_bzero php_explicit_bzero
 #endif
 
+#ifndef HAVE_MEMMEM
+BEGIN_EXTERN_C()
+void* memmem(const void *haystack, size_t hlen, const void *needle, size_t nlen);
+END_EXTERN_C()
+#endif
+
 #ifndef HAVE_STRTOK_R
 BEGIN_EXTERN_C()
 char *strtok_r(char *s, const char *delim, char **last);