libreplace: some systems don't have memmem()

added rep_memmem() and a testsuite
(cherry picked from commit fef3c910da421e890925e5e61275fc457da87f6e)
(cherry picked from commit 42057793ebb3ccdc4e63f59753bca8dd677e9748)

4 files changed, 68 insertions, 0 deletions

diff --git a/lib/replace/libreplace.m4 b/lib/replace/libreplace.m4
index af8587938d1..1353c1f7d26 100644
--- a/lib/replace/libreplace.m4
+++ b/lib/replace/libreplace.m4
@@ -228,6 +228,8 @@ AC_HAVE_DECL(environ, [#include <unistd.h>])
 AC_CHECK_FUNCS(strnlen)
 AC_CHECK_FUNCS(strtoull __strtoull strtouq strtoll __strtoll strtoq)
 
+AC_CHECK_FUNCS(memmem)
+
 # this test disabled as we don't actually need __VA_ARGS__ yet
 AC_TRY_CPP([
 #define eprintf(...) fprintf(stderr, __VA_ARGS__)
diff --git a/lib/replace/replace.c b/lib/replace/replace.c
index fc15717349e..17fd46bcc89 100644
--- a/lib/replace/replace.c
+++ b/lib/replace/replace.c
@@ -681,3 +681,26 @@ char *rep_realpath(const char *path, char *resolved_path)
 	return NULL;
 }
 #endif
+
+
+#ifndef HAVE_MEMMEM
+void *rep_memmem(const void *haystack, size_t haystacklen,
+		 const void *needle, size_t needlelen)
+{
+	if (needlelen == 0) {
+		return discard_const(haystack);
+	}
+	while (haystacklen >= needlelen) {
+		char *p = memchr(haystack, *(const char *)needle,
+				 haystacklen-(needlelen-1));
+		if (!p) return NULL;
+		if (memcmp(p, needle, needlelen) == 0) {
+			return p;
+		}
+		haystack = p+1;
+		haystacklen -= (p - (const char *)haystack) + 1;
+	}
+	return NULL;
+}
+#endif
+
diff --git a/lib/replace/replace.h b/lib/replace/replace.h
index 6424d10c0f9..baf2368130c 100644
--- a/lib/replace/replace.h
+++ b/lib/replace/replace.h
@@ -140,6 +140,12 @@ char *rep_strdup(const char *s);
 void *rep_memmove(void *dest,const void *src,int size);
 #endif
 
+#ifndef HAVE_MEMMEM
+#define memmem rep_memmem
+void *rep_memmem(const void *haystack, size_t haystacklen,
+		 const void *needle, size_t needlelen);
+#endif
+
 #ifndef HAVE_MKTIME
 #define mktime rep_mktime
 /* prototype is in "system/time.h" */
diff --git a/lib/replace/test/testsuite.c b/lib/replace/test/testsuite.c
index 7929f11addf..caa70d68e39 100644
--- a/lib/replace/test/testsuite.c
+++ b/lib/replace/test/testsuite.c
@@ -1015,6 +1015,42 @@ static int test_utimes(void)
 	return true;
 }
 
+static int test_memmem(void)
+{
+	char *s;
+
+	printf("test: memmem\n");
+
+	s = memmem("foo", 3, "fo", 2);
+	if (strcmp(s, "foo") != 0) {
+		printf(__location__ ": Failed memmem\n");
+		return false;
+	}
+
+	s = memmem("foo", 3, "", 0);
+	if (strcmp(s, "foo") != 0) {
+		printf(__location__ ": Failed memmem\n");
+		return false;
+	}
+
+	s = memmem("foo", 4, "o", 1);
+	if (strcmp(s, "oo") != 0) {
+		printf(__location__ ": Failed memmem\n");
+		return false;
+	}
+
+	s = memmem("foobarfodx", 11, "fod", 3);
+	if (strcmp(s, "fodx") != 0) {
+		printf(__location__ ": Failed memmem\n");
+		return false;
+	}
+
+	printf("success: memmem\n");
+
+	return true;
+}
+
+
 struct torture_context;
 bool torture_local_replace(struct torture_context *ctx)
 {
@@ -1065,6 +1101,7 @@ bool torture_local_replace(struct torture_context *ctx)
 	ret &= test_getifaddrs();
 	ret &= test_utime();
 	ret &= test_utimes();
+	ret &= test_memmem();
 
 	return ret;
 }