util: switch iobuf to uint8_t to avoid sign issues

char is signed or unsigned, so let's avoid this by using uint8_t.

src/brei-shared.c

@@ -340,7 +340,7 @@ brei_marshal_message(struct brei_context *brei,
 	size_t message_len = iobuf_len(buf) + sizeof(struct brei_header);
 	uint32_t header[4] = {0, 0, message_len, opcode};
 	memcpy(header, &id, sizeof(id));
-	iobuf_prepend(buf, (const char *)header, sizeof(header));
+	iobuf_prepend(buf, header, sizeof(header));
 
 	return brei_result_new_success(steal(&buf));
 }

src/util-io.c

@@ -123,7 +123,7 @@ xsend_with_fd(int fd, const void *buf, size_t len, int *fds)
 struct iobuf {
 	size_t sz;
 	size_t len;
-	char *data;
+	uint8_t *data;
 	int fds[32];
 };
 
@@ -131,7 +131,7 @@ struct iobuf *
 iobuf_new(size_t size)
 {
 	struct iobuf *buf = malloc(sizeof(*buf));
-	char *data = malloc(size);
+	uint8_t *data = malloc(size);
 
 	assert(buf);
 	assert(data);
@@ -182,7 +182,7 @@ iobuf_pop(struct iobuf *buf, size_t nbytes)
  * The returned pointer only valid in the immediate scope, any iobuf
  * function may invalidate the pointer.
  */
-const char *
+const uint8_t *
 iobuf_data(struct iobuf *buf)
 {
 	return buf->data;
@@ -194,7 +194,7 @@ iobuf_data(struct iobuf *buf)
  * The returned pointer only valid in the immediate scope, any iobuf
  * function may invalidate the pointer.
  */
-const char *
+const uint8_t *
 iobuf_data_end(struct iobuf *buf)
 {
 	return buf->data + buf->len;
@@ -216,7 +216,7 @@ iobuf_take_fd(struct iobuf *buf)
 static inline void
 iobuf_resize(struct iobuf *buf, size_t to_size)
 {
-	char *newdata = realloc(buf->data, to_size);
+	uint8_t *newdata = realloc(buf->data, to_size);
 	assert(newdata);
 
 	buf->data = newdata;
@@ -235,10 +235,10 @@ iobuf_extend(struct iobuf *buf, size_t extra)
  * Remove the data bytes from the buffer. The caller must free() the data.
  * The buffer state is the same as iobuf_new() after this call.
  */
-char *
+uint8_t *
 iobuf_take_data(struct iobuf *buf)
 {
-	char *data = buf->data;
+	uint8_t *data = buf->data;
 
 	buf->data = NULL;
 	buf->len = 0;
@@ -252,7 +252,7 @@ iobuf_take_data(struct iobuf *buf)
  * size it is resized automatically.
  */
 void
-iobuf_append(struct iobuf *buf, const char *data, size_t len)
+iobuf_append(struct iobuf *buf, const void *data, size_t len)
 {
 	if (len == 0)
 		return;
@@ -296,7 +296,7 @@ iobuf_append_f32(struct iobuf *buf, float data)
  * Prepend the given data to the buffer.
  */
 void
-iobuf_prepend(struct iobuf *buf, const char *data, size_t len)
+iobuf_prepend(struct iobuf *buf, const void *data, size_t len)
 {
 	if (len == 0)
 		return;
@@ -498,7 +498,7 @@ MUNIT_TEST(test_iobuf_append_prepend)
 	munit_assert_size(buf->sz, ==, 10);
 
 	/* we don't have a trailing \0 */
-	const char *bufdata = iobuf_data(buf);
+	const uint8_t *bufdata = iobuf_data(buf);
 	munit_assert_char(bufdata[0], ==, 'f');
 	munit_assert_char(bufdata[1], ==, 'o');
 	munit_assert_char(bufdata[2], ==, 'o');
@@ -530,7 +530,7 @@ MUNIT_TEST(test_iobuf_append_prepend)
 	munit_assert_size(iobuf_len(buf), ==, expected_size);
 	munit_assert_size(buf->sz, ==, expected_size);
 	/* now we have a trailing \0 */
-	munit_assert_string_equal(iobuf_data(buf), "barfoodata forcing resize");
+	munit_assert_string_equal((const char *)iobuf_data(buf), "barfoodata forcing resize");
 
 	/* and again with prepending */
 	const char prepend_data2[] = "second resize";
@@ -539,7 +539,7 @@ MUNIT_TEST(test_iobuf_append_prepend)
 
 	munit_assert_size(iobuf_len(buf), ==, expected_size);
 	munit_assert_size(buf->sz, ==, expected_size);
-	munit_assert_string_equal(iobuf_data(buf), "second resizebarfoodata forcing resize");
+	munit_assert_string_equal((const char *)iobuf_data(buf), "second resizebarfoodata forcing resize");
 
 	return MUNIT_OK;
 }
@@ -555,7 +555,7 @@ MUNIT_TEST(test_iobuf_append_values)
 	munit_assert_size(iobuf_len(buf), ==, expected_size);
 	munit_assert_size(buf->sz, ==, 10);
 
-	const char *bufdata = iobuf_data(buf);
+	const uint8_t *bufdata = iobuf_data(buf);
 	munit_assert_int(bufdata[0], ==, 0xff);
 	munit_assert_int(bufdata[1], ==, 0xff);
 	munit_assert_int(bufdata[2], ==, 0xff);
@@ -599,7 +599,7 @@ MUNIT_TEST(test_iobuf_prepend_empty_buffer)
 	munit_assert_size(buf->sz, ==, 10);
 
 	/* we don't have a trailing \0 */
-	const char *bufdata = iobuf_data(buf);
+	const uint8_t *bufdata = iobuf_data(buf);
 	munit_assert_char(bufdata[0], ==, 'f');
 	munit_assert_char(bufdata[1], ==, 'o');
 	munit_assert_char(bufdata[2], ==, 'o');
@@ -618,7 +618,7 @@ MUNIT_TEST(test_iobuf_pop)
 	munit_assert_size(iobuf_len(buf), ==, 3);
 
 	/* we don't have a trailing \0 */
-	const char *bufdata = iobuf_data(buf);
+	const uint8_t *bufdata = iobuf_data(buf);
 	munit_assert_char(bufdata[0], ==, 'b');
 	munit_assert_char(bufdata[1], ==, 'a');
 	munit_assert_char(bufdata[2], ==, 'r');
@@ -640,8 +640,7 @@ MUNIT_TEST(test_iobuf_append_short)
 	munit_assert_size(buf->len, ==, 4);
 	munit_assert_size(iobuf_len(buf), ==, 4);
 	munit_assert_size(buf->sz, ==, 10);
-	munit_assert_string_equal(iobuf_data(buf),
-				  "foo");
+	munit_assert_string_equal((const char *)iobuf_data(buf), "foo");
 
 	return MUNIT_OK;
 }
@@ -671,7 +670,7 @@ MUNIT_TEST(test_iobuf_append_fd)
 	/* so we can do strcmp */
 	const char nullbyte = '\0';
 	iobuf_append(buf, &nullbyte, 1);
-	munit_assert_string_equal(iobuf_data(buf), "foob");
+	munit_assert_string_equal((const char *)iobuf_data(buf), "foob");
 
 	/* read when there's nothing waiting */
 	int blocking_read = iobuf_append_from_fd(buf, rd);

src/util-io.h

@@ -266,7 +266,7 @@ iobuf_len(struct iobuf *buf);
  * The returned pointer only valid in the immediate scope, any iobuf
  * function may invalidate the pointer.
  */
-const char *
+const uint8_t *
 iobuf_data(struct iobuf *buf);
 
 /**
@@ -275,7 +275,7 @@ iobuf_data(struct iobuf *buf);
  * The returned pointer only valid in the immediate scope, any iobuf
  * function may invalidate the pointer.
  */
-const char *
+const uint8_t *
 iobuf_data_end(struct iobuf *buf);
 
 /**
@@ -289,7 +289,7 @@ iobuf_take_fd(struct iobuf *buf);
  * Remove the data bytes from the buffer. The caller must free() the data.
  * The buffer state is the same as iobuf_new() after this call.
  */
-char *
+uint8_t *
 iobuf_take_data(struct iobuf *buf);
 
 /**
@@ -303,7 +303,7 @@ iobuf_pop(struct iobuf *buf, size_t nbytes);
  * size it is resized automatically.
  */
 void
-iobuf_append(struct iobuf *buf, const char *data, size_t len);
+iobuf_append(struct iobuf *buf, const void *data, size_t len);
 
 /**
  * Append one 32-bit value to the buffer. If the data exceeds the current buffer
@@ -331,7 +331,7 @@ iobuf_append_f32(struct iobuf *buf, float data);
  * size it is resized automatically.
  */
 void
-iobuf_prepend(struct iobuf *buf, const char *data, size_t len);
+iobuf_prepend(struct iobuf *buf, const void *data, size_t len);
 
 /**
  * Append a file descriptor to the buffer. The file descriptor is dup()ed.