s3:libsmb: add an option to cli_push to let the caller provide the buffers

[ira/wip.git] / source3 / libsmb / clireadwrite.c

diff --git a/source3/libsmb/clireadwrite.c b/source3/libsmb/clireadwrite.c
index f2f447b4c95661f7d87190473afd6f4b200cc073..7e7cf0d682129a26c173f99061a9cb671ff72704 100644 (file)
--- a/source3/libsmb/clireadwrite.c
+++ b/source3/libsmb/clireadwrite.c
@@ -930,8 +930,11 @@ struct cli_push_state {
        uint16_t mode;
        off_t start_offset;
        size_t window_size;
+       bool caller_buffers;
 
-       size_t (*source)(uint8_t *buf, size_t n, void *priv);
+       size_t (*source)(uint8_t *inbuf, size_t n,
+                        const uint8_t **outbuf,
+                        void *priv);
        void *priv;
 
        bool eof;
@@ -963,13 +966,21 @@ static bool cli_push_write_setup(struct async_req *req,
        substate->req = req;
        substate->idx = idx;
        substate->ofs = state->next_offset;
-       substate->buf = talloc_array(substate, uint8_t, state->chunk_size);
-       if (!substate->buf) {
-               talloc_free(substate);
-               return false;
+       if (state->caller_buffers) {
+               substate->buf = NULL;
+       } else {
+               substate->buf = talloc_array(substate, uint8_t,
+                                            state->chunk_size);
+               if (!substate->buf) {
+                       talloc_free(substate);
+                       return false;
+               }
        }
+
+       /* source function can overwrite substate->buf... */
        substate->size = state->source(substate->buf,
                                       state->chunk_size,
+                                      (const uint8_t **)&substate->buf,
                                       state->priv);
        if (substate->size == 0) {
                state->eof = true;
@@ -1002,7 +1013,9 @@ struct async_req *cli_push_send(TALLOC_CTX *mem_ctx, struct event_context *ev,
                                struct cli_state *cli,
                                uint16_t fnum, uint16_t mode,
                                off_t start_offset, size_t window_size,
-                               size_t (*source)(uint8_t *buf, size_t n,
+                               bool caller_buffers,
+                               size_t (*source)(uint8_t *inbuf, size_t n,
+                                                const uint8_t **outbuf,
                                                 void *priv),
                                void *priv)
 {
@@ -1019,6 +1032,7 @@ struct async_req *cli_push_send(TALLOC_CTX *mem_ctx, struct event_context *ev,
        state->fnum = fnum;
        state->start_offset = start_offset;
        state->mode = mode;
+       state->caller_buffers = caller_buffers;
        state->source = source;
        state->priv = priv;
        state->eof = false;
@@ -1108,7 +1122,10 @@ NTSTATUS cli_push_recv(struct async_req *req)
 
 NTSTATUS cli_push(struct cli_state *cli, uint16_t fnum, uint16_t mode,
                  off_t start_offset, size_t window_size,
-                 size_t (*source)(uint8_t *buf, size_t n, void *priv),
+                 bool caller_buffers,
+                 size_t (*source)(uint8_t *inbuf, size_t n,
+                                  const uint8_t **outbuf,
+                                  void *priv),
                  void *priv)
 {
        TALLOC_CTX *frame = talloc_stackframe();
@@ -1129,7 +1146,7 @@ NTSTATUS cli_push(struct cli_state *cli, uint16_t fnum, uint16_t mode,
        }
 
        req = cli_push_send(frame, ev, cli, fnum, mode, start_offset,
-                           window_size, source, priv);
+                           window_size, caller_buffers, source, priv);
        if (req == NULL) {
                goto nomem;
        }