+ if (new_iov == NULL) {
+ return -ENOMEM;
+ }
+
+ /* Allocate new chunks as needed into new_iov */
+ for (i = qsb->n_iov; i < qsb->n_iov + needed_chunks; i++) {
+ new_iov[i].iov_base = g_try_malloc0(chunk_size);
+ new_iov[i].iov_len = chunk_size;
+ if (!new_iov[i].iov_base) {
+ size_t j;
+
+ /* Free previously allocated new chunks */
+ for (j = qsb->n_iov; j < i; j++) {
+ g_free(new_iov[j].iov_base);
+ }
+ g_free(new_iov);
+
+ return -ENOMEM;
+ }
+ }
+
+ /*
+ * Now we can't get any allocation errors, copy over to new iov
+ * and switch.
+ */
+ for (i = 0; i < qsb->n_iov; i++) {
+ new_iov[i] = qsb->iov[i];
+ }
+
+ qsb->n_iov += needed_chunks;
+ g_free(qsb->iov);
+ qsb->iov = new_iov;
+ qsb->size += (needed_chunks * chunk_size);
+ }
+
+ return qsb->size;
+}
+
+/**
+ * Write into the QEMUSizedBuffer at a given position and a given
+ * number of bytes. This function will automatically grow the
+ * QEMUSizedBuffer.
+ *
+ * @qsb: A QEMUSizedBuffer
+ * @source: A byte array to copy data from
+ * @pos: The position within the @qsb to write data to
+ * @size: The number of bytes to copy into the @qsb
+ *
+ * Returns @size or a negative error code in case of memory allocation failure,
+ * or with an invalid 'pos'
+ */
+ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *source,
+ off_t pos, size_t count)
+{
+ ssize_t rc = qsb_grow(qsb, pos + count);
+ size_t to_copy;
+ size_t all_copy = count;
+ const struct iovec *iov;
+ ssize_t index;
+ char *dest;
+ off_t d_off, s_off = 0;
+
+ if (rc < 0) {
+ return rc;
+ }
+
+ if (pos + count > qsb->used) {
+ qsb->used = pos + count;
+ }
+
+ index = qsb_get_iovec(qsb, pos, &d_off);
+ if (index < 0) {
+ return -EINVAL;
+ }
+
+ while (all_copy > 0) {
+ iov = &qsb->iov[index];
+
+ dest = iov->iov_base;
+
+ to_copy = iov->iov_len - d_off;
+ if (to_copy > all_copy) {
+ to_copy = all_copy;
+ }
+
+ memcpy(&dest[d_off], &source[s_off], to_copy);
+
+ s_off += to_copy;
+ all_copy -= to_copy;
+
+ d_off = 0;
+ index++;
+ }
+
+ return count;
+}
+
+/**
+ * Create a deep copy of the given QEMUSizedBuffer.
+ *
+ * @qsb: A QEMUSizedBuffer
+ *
+ * Returns a clone of @qsb or NULL on allocation failure
+ */
+QEMUSizedBuffer *qsb_clone(const QEMUSizedBuffer *qsb)
+{
+ QEMUSizedBuffer *out = qsb_create(NULL, qsb_get_length(qsb));
+ size_t i;
+ ssize_t res;
+ off_t pos = 0;
+
+ if (!out) {
+ return NULL;
+ }
+
+ for (i = 0; i < qsb->n_iov; i++) {
+ res = qsb_write_at(out, qsb->iov[i].iov_base,
+ pos, qsb->iov[i].iov_len);
+ if (res < 0) {
+ qsb_free(out);
+ return NULL;
+ }
+ pos += res;
+ }
+
+ return out;
+}
+
+typedef struct QEMUBuffer {
+ QEMUSizedBuffer *qsb;
+ QEMUFile *file;
+} QEMUBuffer;
+
+static int buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
+{
+ QEMUBuffer *s = opaque;
+ ssize_t len = qsb_get_length(s->qsb) - pos;
+
+ if (len <= 0) {
+ return 0;
+ }
+
+ if (len > size) {
+ len = size;
+ }
+ return qsb_get_buffer(s->qsb, pos, len, buf);
+}
+
+static int buf_put_buffer(void *opaque, const uint8_t *buf,
+ int64_t pos, int size)
+{
+ QEMUBuffer *s = opaque;
+
+ return qsb_write_at(s->qsb, buf, pos, size);
+}
+
+static int buf_close(void *opaque)
+{
+ QEMUBuffer *s = opaque;
+
+ qsb_free(s->qsb);
+
+ g_free(s);
+
+ return 0;
+}
+
+const QEMUSizedBuffer *qemu_buf_get(QEMUFile *f)
+{
+ QEMUBuffer *p;
+
+ qemu_fflush(f);
+
+ p = f->opaque;
+
+ return p->qsb;
+}
+
+static const QEMUFileOps buf_read_ops = {
+ .get_buffer = buf_get_buffer,
+ .close = buf_close,
+};
+
+static const QEMUFileOps buf_write_ops = {
+ .put_buffer = buf_put_buffer,
+ .close = buf_close,
+};
+
+QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input)
+{
+ QEMUBuffer *s;
+
+ if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') ||
+ mode[1] != '\0') {
+ error_report("qemu_bufopen: Argument validity check failed");
+ return NULL;
+ }
+
+ s = g_malloc0(sizeof(QEMUBuffer));
+ if (mode[0] == 'r') {
+ s->qsb = input;
+ }
+
+ if (s->qsb == NULL) {
+ s->qsb = qsb_create(NULL, 0);
+ }
+ if (!s->qsb) {
+ g_free(s);
+ error_report("qemu_bufopen: qsb_create failed");
+ return NULL;
+ }
+
+
+ if (mode[0] == 'r') {
+ s->file = qemu_fopen_ops(s, &buf_read_ops);
+ } else {
+ s->file = qemu_fopen_ops(s, &buf_write_ops);
+ }
+ return s->file;
+}
