lib: Curl_read/Curl_write clarifications

- replace `Curl_read()`, `Curl_write()` and `Curl_nwrite()` to
  clarify when and at what level they operate
- send/recv of transfer related data is now done via
  `Curl_xfer_send()/Curl_xfer_recv()` which no longer has
  socket/socketindex as parameter. It decides on the transfer
  setup of `conn->sockfd` and `conn->writesockfd` on which
  connection filter chain to operate.
- send/recv on a specific connection filter chain is done via
  `Curl_conn_send()/Curl_conn_recv()` which get the socket index
  as parameter.
- rename `Curl_setup_transfer()` to `Curl_xfer_setup()` for
  naming consistency
- clarify that the special CURLE_AGAIN hangling to return
  `CURLE_OK` with length 0 only applies to `Curl_xfer_send()`
  and CURLE_AGAIN is returned by all other send() variants.
- fix a bug in websocket `curl_ws_recv()` that mixed up data
  when it arrived in more than a single chunk (to be made
  into a sperate PR, also)

Added as documented [in
CLIENT-READER.md](https://github.com/curl/curl/blob/5b1f31dfbab8aef467c419c68aa06dc738cb75d4/docs/CLIENT-READERS.md).

- old `Curl_buffer_send()` completely replaced by new `Curl_req_send()`
- old `Curl_fillreadbuffer()` replaced with `Curl_client_read()`
- HTTP chunked uploads are now formatted in a client reader added when
  needed.
- FTP line-end conversions are done in a client reader added when
  needed.
- when sending requests headers, remaining buffer space is filled with
  body data for sending in "one go". This is independent of the request
  body size. Resolves #12938 as now small and large requests have the
  same code path.

Changes done to test cases:

- test513: now fails before sending request headers as this initial
  "client read" triggers the setup fault. Behaves now the same as in
  hyper build
- test547, test555, test1620: fix the length check in the lib code to
  only fail for reads *smaller* than expected. This was a bug in the
  test code that never triggered in the old implementation.

Closes #12969

docs/CLIENT-READERS.md

@@ -0,0 +1,93 @@
+# curl client readers
+
+Client readers is a design in the internals of libcurl, not visible in its public API. They were started
+in curl v8.7.0. This document describes the concepts, its high level implementation and the motivations.
+
+## Naming
+
+`libcurl` operates between clients and servers. A *client* is the application using libcurl, like the command line tool `curl` itself. Data to be uploaded to a server is **read** from the client and **sent** to the server, the servers response is **received** by `libcurl` and then **written** to the client.
+
+With this naming established, client readers are concerned with providing data from the application to the server. Applications register callbacks via `CURLOPT_READFUNCTION`, data via `CURLOPT_POSTFIELDS` and other options to be used by `libcurl` when the request is send.
+
+## Invoking
+
+The transfer loop that sends and receives, is using `Curl_client_read()` to get more data to send for a transfer. If no specific reader has been installed yet, the default one that uses `CURLOPT_READFUNCTION` is added. The prototype is
+
+```
+CURLcode Curl_client_read(struct Curl_easy *data, char *buf, size_t blen,
+                          size_t *nread, bool *eos);
+```
+The arguments are the transfer to read for, a buffer to hold the read data, its length, the actual number of bytes placed into the buffer and the `eos` (*end of stream*) flag indicating that no more data is available. The `eos` flag may be set for a read amount, if that amount was the last. That way curl can avoid to read an additional time.
+
+The implementation of `Curl_client_read()` uses a chain of *client reader* instances to get the data. This is similar to the design of *client writers*. The chain of readers allows processing of the data to send.
+
+The definition of a reader is:
+
+```
+struct Curl_crtype {
+  const char *name;        /* writer name. */
+  CURLcode (*do_init)(struct Curl_easy *data, struct Curl_creader *writer);
+  CURLcode (*do_read)(struct Curl_easy *data, struct Curl_creader *reader,
+                      char *buf, size_t blen, size_t *nread, bool *eos);
+  void (*do_close)(struct Curl_easy *data, struct Curl_creader *reader);
+  bool (*needs_rewind)(struct Curl_easy *data, struct Curl_creader *reader);
+};
+
+struct Curl_creader {
+  const struct Curl_crtype *crt;  /* type implementation */
+  struct Curl_creader *next;  /* Downstream reader. */
+  Curl_creader_phase phase; /* phase at which it operates */
+};
+```
+
+`Curl_creader` is a reader instance with a `next` pointer to form the chain. It as a type `crt` which provides the implementation. The main callback is `do_read()` which provides the data to the caller. The others are for setup and tear down. `needs_rewind()` is explained further below.
+
+## Phases and Ordering
+
+Since client readers may transform the data being read through the chain, the order in which they are called is relevant for the outcome. When a reader is created, it gets the `phase` property in which it operates. Reader phases are defined like:
+
+```
+typedef enum {
+  CURL_CR_NET,  /* data send to the network (connection filters) */
+  CURL_CR_TRANSFER_ENCODE, /* add transfer-encodings */
+  CURL_CR_PROTOCOL, /* before transfer, but after content decoding */
+  CURL_CR_CONTENT_ENCODE, /* add content-encodings */
+  CURL_CR_CLIENT  /* data read from client */
+} Curl_creader_phase;
+```
+
+If a reader for phase `PROTOCOL` is added to the chain, it is always added *after* any `NET` or `TRANSFER_ENCODE` readers and *before* and `CONTENT_ENCODE` and `CLIENT` readers. If there is already a reader for the same phase, the new reader is added before the existing one(s).
+
+### Example: `chunked` reader
+
+In `http_chunks.c` a client reader for chunked uploads is implemented. This one operates at phase `CURL_CR_TRANSFER_ENCODE`. Any data coming from the reader "below" has the HTTP/1.1 chunk handling applied and returned to the caller.
+
+When this reader sees an `eos` from below, it generates the terminal chunk, adding trailers if provided by the application. When that last chunk is fully returned, it also sets `eos` to the caller.
+
+### Example: `lineconv` reader
+
+In `sendf.c` a client reader that does line-end conversions is implemented. It operates at `CURL_CR_CONTENT_ENCODE` and converts any "\n" to "\r\n". This is used for FTP ASCII uploads or when the general `crlf` options has been set.
+
+### Example: `null` reader
+
+Implemented in `sendf.c` for phase `CURL_CR_CLIENT`, this reader has the simple job of providing transfer bytes of length 0 to the caller, immediately indicating an `eos`. This reader is installed by HTTP for all GET/HEAD requests and when authentication is being negotiated.
+
+### Example: `buf` reader
+
+Implemented in `sendf.c` for phase `CURL_CR_CLIENT`, this reader get a buffer pointer and a length and provides exactly these bytes. This one is used in HTTP for sending `postfields` provided by the application.
+
+## Request retries
+
+Sometimes it is necessary to send a request with client data again. Transfer handling can inquire via `Curl_client_read_needs_rewind()` if a rewind (e.g. a reset of the client data) is necessary. This asks all installed readers if they need it and give `FALSE` of none does.
+
+## Summary and Outlook
+
+By adding the client reader interface, any protocol can control how/if it wants the curl transfer to send bytes for a request. The transfer loop becomes then blissfully ignorant of the specifics. 
+
+The protocols on the other hand no longer have to care to package data most efficiently. At any time, should more data be needed, it can be read from the client. This is used when sending HTTP requests headers to add as much request body data to the initial sending as there is room for.
+
+Future enhancements based on the client readers:
+* delegate the actual "rewinding" to the readers. The should know how it is done, eliminating the `readrewind.c` protocol specifics in `multi.c`.
+* `expect-100` handling: place that into a HTTP specific reader at `CURL_CR_PROTOCOL` and eliminate the checks in the generic transfer parts.
+* `eos` detection: `upload_done` is partly triggered now by comparing the number of bytes sent to a known size. This is no longer necessary since the core readers obey length restrictions.
+* `eos forwarding`: transfer should forward an `eos` flag to the connection filters. Filters like HTTP/2 and HTTP/3 can make use of that, terminating streams early. This would also eliminate length checks in stream handling.

docs/Makefile.am

@@ -56,6 +56,7 @@ EXTRA_DIST =                                    \
  CODE_OF_CONDUCT.md                             \
  CODE_REVIEW.md                                 \
  CODE_STYLE.md                                  \
+ CLIENT-READERS.md                              \
  CLIENT-WRITERS.md                              \
  CONNECTION-FILTERS.md                          \
  CONTRIBUTE.md                                  \

lib/bufq.c

@@ -417,6 +417,17 @@ ssize_t Curl_bufq_write(struct bufq *q,
   return nwritten;
 }
 
+CURLcode Curl_bufq_cwrite(struct bufq *q,
+                          const char *buf, size_t len,
+                          size_t *pnwritten)
+{
+  ssize_t n;
+  CURLcode result;
+  n = Curl_bufq_write(q, (const unsigned char *)buf, len, &result);
+  *pnwritten = (n < 0)? 0 : (size_t)n;
+  return result;
+}
+
 ssize_t Curl_bufq_read(struct bufq *q, unsigned char *buf, size_t len,
                        CURLcode *err)
 {
@@ -440,6 +451,16 @@ ssize_t Curl_bufq_read(struct bufq *q, unsigned char *buf, size_t len,
   return nread;
 }
 
+CURLcode Curl_bufq_cread(struct bufq *q, char *buf, size_t len,
+                         size_t *pnread)
+{
+  ssize_t n;
+  CURLcode result;
+  n = Curl_bufq_read(q, (unsigned char *)buf, len, &result);
+  *pnread = (n < 0)? 0 : (size_t)n;
+  return result;
+}
+
 bool Curl_bufq_peek(struct bufq *q,
                     const unsigned char **pbuf, size_t *plen)
 {

lib/bufq.h

@@ -178,6 +178,10 @@ ssize_t Curl_bufq_write(struct bufq *q,
                         const unsigned char *buf, size_t len,
                         CURLcode *err);
 
+CURLcode Curl_bufq_cwrite(struct bufq *q,
+                         const char *buf, size_t len,
+                         size_t *pnwritten);
+
 /**
  * Read buf from the start of the buffer queue. The buf is copied
  * and the amount of copied bytes is returned.
@@ -187,6 +191,9 @@ ssize_t Curl_bufq_write(struct bufq *q,
 ssize_t Curl_bufq_read(struct bufq *q, unsigned char *buf, size_t len,
                         CURLcode *err);
 
+CURLcode Curl_bufq_cread(struct bufq *q, char *buf, size_t len,
+                         size_t *pnread);
+
 /**
  * Peek at the head chunk in the buffer queue. Returns a pointer to
  * the chunk buf (at the current offset) and its length. Does not

lib/c-hyper.c

@@ -117,8 +117,6 @@ size_t Curl_hyper_send(void *userp, hyper_context *ctx,
   DEBUGF(infof(data, "Curl_hyper_send(%zu)", buflen));
   result = Curl_conn_send(data, io_ctx->sockindex,
                           (void *)buf, buflen, &nwrote);
-  if(!result && !nwrote)
-    result = CURLE_AGAIN;
   if(result == CURLE_AGAIN) {
     DEBUGF(infof(data, "Curl_hyper_send(%zu) -> EAGAIN", buflen));
     /* would block, register interest */
@@ -659,48 +657,13 @@ static CURLcode request_target(struct Curl_easy *data,
   return result;
 }
 
-static int uploadpostfields(void *userdata, hyper_context *ctx,
-                            hyper_buf **chunk)
-{
-  struct Curl_easy *data = (struct Curl_easy *)userdata;
-  (void)ctx;
-  if(data->req.exp100 > EXP100_SEND_DATA) {
-    if(data->req.exp100 == EXP100_FAILED)
-      return HYPER_POLL_ERROR;
-
-    /* still waiting confirmation */
-    if(data->hyp.exp100_waker)
-      hyper_waker_free(data->hyp.exp100_waker);
-    data->hyp.exp100_waker = hyper_context_waker(ctx);
-    return HYPER_POLL_PENDING;
-  }
-  if(data->req.upload_done)
-    *chunk = NULL; /* nothing more to deliver */
-  else {
-    /* send everything off in a single go */
-    hyper_buf *copy = hyper_buf_copy(data->set.postfields,
-                                     (size_t)data->req.p.http->postsize);
-    if(copy)
-      *chunk = copy;
-    else {
-      data->state.hresult = CURLE_OUT_OF_MEMORY;
-      return HYPER_POLL_ERROR;
-    }
-    /* increasing the writebytecount here is a little premature but we
-       don't know exactly when the body is sent */
-    data->req.writebytecount += (size_t)data->req.p.http->postsize;
-    Curl_pgrsSetUploadCounter(data, data->req.writebytecount);
-    data->req.upload_done = TRUE;
-  }
-  return HYPER_POLL_READY;
-}
-
 static int uploadstreamed(void *userdata, hyper_context *ctx,
                           hyper_buf **chunk)
 {
   size_t fillcount;
   struct Curl_easy *data = (struct Curl_easy *)userdata;
   CURLcode result;
+  bool eos;
   (void)ctx;
 
   if(data->req.exp100 > EXP100_SEND_DATA) {
@@ -714,32 +677,15 @@ static int uploadstreamed(void *userdata, hyper_context *ctx,
     return HYPER_POLL_PENDING;
   }
 
-  if(data->req.upload_chunky && data->req.authneg) {
-    fillcount = 0;
-    data->req.upload_chunky = FALSE;
-    result = CURLE_OK;
-  }
-  else {
-    result = Curl_fillreadbuffer(data, data->set.upload_buffer_size,
-                                 &fillcount);
-  }
+  result = Curl_client_read(data, data->state.ulbuf,
+                            data->set.upload_buffer_size,
+                            &fillcount, &eos);
   if(result) {
     data->state.hresult = result;
     return HYPER_POLL_ERROR;
   }
-  if(!fillcount) {
-    if((data->req.keepon & KEEP_SEND_PAUSE) != KEEP_SEND_PAUSE)
-      /* done! */
-      *chunk = NULL;
-    else {
-      /* paused, save a waker */
-      if(data->hyp.send_body_waker)
-        hyper_waker_free(data->hyp.send_body_waker);
-      data->hyp.send_body_waker = hyper_context_waker(ctx);
-      return HYPER_POLL_PENDING;
-    }
-  }
-  else {
+
+  if(fillcount) {
     hyper_buf *copy = hyper_buf_copy((uint8_t *)data->state.ulbuf, fillcount);
     if(copy)
       *chunk = copy;
@@ -751,8 +697,19 @@ static int uploadstreamed(void *userdata, hyper_context *ctx,
        don't know exactly when the body is sent */
     data->req.writebytecount += fillcount;
     Curl_pgrsSetUploadCounter(data, data->req.writebytecount);
+    return HYPER_POLL_READY;
+  }
+  else if(eos) {
+    *chunk = NULL;
+    return HYPER_POLL_READY;
+  }
+  else {
+    /* paused, save a waker */
+    if(data->hyp.send_body_waker)
+      hyper_waker_free(data->hyp.send_body_waker);
+    data->hyp.send_body_waker = hyper_context_waker(ctx);
+    return HYPER_POLL_PENDING;
   }
-  return HYPER_POLL_READY;
 }
 
 /*
@@ -773,7 +730,7 @@ static CURLcode bodysend(struct Curl_easy *data,
   else {
     hyper_body *body;
     Curl_dyn_init(&req, DYN_HTTP_REQUEST);
-    result = Curl_http_req_send(data, &req, httpreq);
+    result = Curl_http_req_complete(data, &req, httpreq);
 
     if(!result)
       result = Curl_hyper_header(data, headers, Curl_dyn_ptr(&req));
@@ -782,18 +739,15 @@ static CURLcode bodysend(struct Curl_easy *data,
 
     body = hyper_body_new();
     hyper_body_set_userdata(body, data);
-    if(data->set.postfields)
-      hyper_body_set_data_func(body, uploadpostfields);
-    else {
-      result = Curl_get_upload_buffer(data);
-      if(result) {
-        hyper_body_free(body);
-        return result;
-      }
-      /* init the "upload from here" pointer */
-      data->req.upload_fromhere = data->state.ulbuf;
-      hyper_body_set_data_func(body, uploadstreamed);
+    result = Curl_get_upload_buffer(data);
+    if(result) {
+      hyper_body_free(body);
+      return result;
     }
+    /* init the "upload from here" pointer */
+    data->req.upload_fromhere = data->state.ulbuf;
+    hyper_body_set_data_func(body, uploadstreamed);
+
     if(HYPERE_OK != hyper_request_set_body(hyperreq, body)) {
       /* fail */
       result = CURLE_OUT_OF_MEMORY;
@@ -888,7 +842,7 @@ CURLcode Curl_http(struct Curl_easy *data, bool *done)
      may be parts of the request that is not yet sent, since we can deal with
      the rest of the request in the PERFORM phase. */
   *done = TRUE;
-  Curl_cw_reset(data);
+  Curl_client_reset(data);
 
   /* Add collecting of headers written to client. For a new connection,
    * we might have done that already, but reuse

lib/cf-h1-proxy.c

@@ -1013,7 +1013,7 @@ out:
     data->req.header = TRUE; /* assume header */
     data->req.bytecount = 0;
     data->req.ignorebody = FALSE;
-    Curl_cw_reset(data);
+    Curl_client_reset(data);
     Curl_pgrsSetUploadCounter(data, 0);
     Curl_pgrsSetDownloadCounter(data, 0);
 

lib/file.c

@@ -293,10 +293,10 @@ static CURLcode file_upload(struct Curl_easy *data)
   CURLcode result = CURLE_OK;
   char *xfer_buf;
   size_t xfer_blen;
-  char *uphere_save;
   curl_off_t bytecount = 0;
   struct_stat file_stat;
   const char *sendbuf;
+  bool eos = FALSE;
 
   /*
    * Since FILE: doesn't do the full init, we need to provide some extra
@@ -340,21 +340,16 @@ static CURLcode file_upload(struct Curl_easy *data)
     data->state.resume_from = (curl_off_t)file_stat.st_size;
   }
 
-  /* Yikes! Curl_fillreadbuffer uses data->req.upload_fromhere to READ
-   * client data to! Please, someone fix... */
-  uphere_save = data->req.upload_fromhere;
-
   result = Curl_multi_xfer_buf_borrow(data, &xfer_buf, &xfer_blen);
   if(result)
     goto out;
 
-  while(!result) {
+  while(!result && !eos) {
     size_t nread;
     ssize_t nwrite;
     size_t readcount;
 
-    data->req.upload_fromhere = xfer_buf;
-    result = Curl_fillreadbuffer(data, xfer_blen, &readcount);
+    result = Curl_client_read(data, xfer_buf, xfer_blen, &readcount, &eos);
     if(result)
       break;
 
@@ -401,7 +396,6 @@ static CURLcode file_upload(struct Curl_easy *data)
 out:
   close(fd);
   Curl_multi_xfer_buf_release(data, xfer_buf);
-  data->req.upload_fromhere = uphere_save;
 
   return result;
 }

lib/http.c

@@ -543,7 +543,7 @@ static CURLcode http_perhapsrewind(struct Curl_easy *data,
        closure so we can safely do the rewind right now */
   }
 
-  if(bytessent) {
+  if(Curl_client_read_needs_rewind(data)) {
     /* mark for rewind since if we already sent something */
     data->state.rewindbeforesend = TRUE;
     infof(data, "Please rewind output before next send");
@@ -1174,277 +1174,6 @@ static bool http_should_fail(struct Curl_easy *data)
   return data->state.authproblem;
 }
 
-#ifndef USE_HYPER
-/*
- * readmoredata() is a "fread() emulation" to provide POST and/or request
- * data. It is used when a huge POST is to be made and the entire chunk wasn't
- * sent in the first send(). This function will then be called from the
- * transfer.c loop when more data is to be sent to the peer.
- *
- * Returns the amount of bytes it filled the buffer with.
- */
-static size_t readmoredata(char *buffer,
-                           size_t size,
-                           size_t nitems,
-                           void *userp)
-{
-  struct HTTP *http = (struct HTTP *)userp;
-  struct Curl_easy *data = http->backup.data;
-  size_t fullsize = size * nitems;
-
-  if(!http->postsize)
-    /* nothing to return */
-    return 0;
-
-  /* make sure that an HTTP request is never sent away chunked! */
-  data->req.forbidchunk = (http->sending == HTTPSEND_REQUEST)?TRUE:FALSE;
-
-  if(data->set.max_send_speed &&
-     (data->set.max_send_speed < (curl_off_t)fullsize) &&
-     (data->set.max_send_speed < http->postsize))
-    /* speed limit */
-    fullsize = (size_t)data->set.max_send_speed;
-
-  else if(http->postsize <= (curl_off_t)fullsize) {
-    memcpy(buffer, http->postdata, (size_t)http->postsize);
-    fullsize = (size_t)http->postsize;
-
-    if(http->backup.postsize) {
-      /* move backup data into focus and continue on that */
-      http->postdata = http->backup.postdata;
-      http->postsize = http->backup.postsize;
-      data->state.fread_func = http->backup.fread_func;
-      data->state.in = http->backup.fread_in;
-
-      http->sending++; /* move one step up */
-
-      http->backup.postsize = 0;
-    }
-    else
-      http->postsize = 0;
-
-    return fullsize;
-  }
-
-  memcpy(buffer, http->postdata, fullsize);
-  http->postdata += fullsize;
-  http->postsize -= fullsize;
-
-  return fullsize;
-}
-
-/*
- * Curl_buffer_send() sends a header buffer and frees all associated
- * memory.  Body data may be appended to the header data if desired.
- *
- * Returns CURLcode
- */
-static CURLcode buffer_send(struct dynbuf *in,
-                            struct Curl_easy *data,
-                            struct HTTP *http,
-                            /* add the number of sent bytes to this
-                               counter */
-                            curl_off_t *bytes_written,
-                            /* how much of the buffer contains body data */
-                            curl_off_t included_body_bytes)
-{
-  size_t amount;
-  CURLcode result;
-  char *ptr;
-  size_t size;
-  struct connectdata *conn = data->conn;
-  size_t sendsize;
-  size_t headersize;
-
-  /* The looping below is required since we use non-blocking sockets, but due
-     to the circumstances we will just loop and try again and again etc */
-
-  ptr = Curl_dyn_ptr(in);
-  size = Curl_dyn_len(in);
-
-  headersize = size - (size_t)included_body_bytes; /* the initial part that
-                                                      isn't body is header */
-
-  DEBUGASSERT(size > (size_t)included_body_bytes);
-
-  if((conn->handler->flags & PROTOPT_SSL
-#ifndef CURL_DISABLE_PROXY
-      || IS_HTTPS_PROXY(conn->http_proxy.proxytype)
-#endif
-       )
-     && conn->httpversion < 20) {
-    /* Make sure this doesn't send more body bytes than what the max send
-       speed says. The request bytes do not count to the max speed.
-    */
-    if(data->set.max_send_speed &&
-       (included_body_bytes > data->set.max_send_speed)) {
-      curl_off_t overflow = included_body_bytes - data->set.max_send_speed;
-      DEBUGASSERT((size_t)overflow < size);
-      sendsize = size - (size_t)overflow;
-    }
-    else
-      sendsize = size;
-
-    /* OpenSSL is very picky and we must send the SAME buffer pointer to the
-       library when we attempt to re-send this buffer. Sending the same data
-       is not enough, we must use the exact same address. For this reason, we
-       must copy the data to the uploadbuffer first, since that is the buffer
-       we will be using if this send is retried later.
-    */
-    result = Curl_get_upload_buffer(data);
-    if(result) {
-      /* malloc failed, free memory and return to the caller */
-      Curl_dyn_free(in);
-      return result;
-    }
-    /* We never send more than upload_buffer_size bytes in one single chunk
-       when we speak HTTPS, as if only a fraction of it is sent now, this data
-       needs to fit into the normal read-callback buffer later on and that
-       buffer is using this size.
-    */
-    if(sendsize > (size_t)data->set.upload_buffer_size)
-      sendsize = (size_t)data->set.upload_buffer_size;
-
-    memcpy(data->state.ulbuf, ptr, sendsize);
-    ptr = data->state.ulbuf;
-  }
-  else {
-#ifdef CURLDEBUG
-    /* Allow debug builds to override this logic to force short initial
-       sends
-     */
-    char *p = getenv("CURL_SMALLREQSEND");
-    if(p) {
-      size_t altsize = (size_t)strtoul(p, NULL, 10);
-      if(altsize)
-        sendsize = CURLMIN(size, altsize);
-      else
-        sendsize = size;
-    }
-    else
-#endif
-    {
-      /* Make sure this doesn't send more body bytes than what the max send
-         speed says. The request bytes do not count to the max speed.
-      */
-      if(data->set.max_send_speed &&
-         (included_body_bytes > data->set.max_send_speed)) {
-        curl_off_t overflow = included_body_bytes - data->set.max_send_speed;
-        DEBUGASSERT((size_t)overflow < size);
-        sendsize = size - (size_t)overflow;
-      }
-      else
-        sendsize = size;
-    }
-
-    /* We currently cannot send more that this for http here:
-     * - if sending blocks, it return 0 as amount
-     * - we then whisk aside the `in` into the `http` struct
-     *   and install our own `data->state.fread_func` that
-     *   on subsequent calls reads `in` empty.
-     * - when the whisked away `in` is empty, the `fread_func`
-     *   is restored to its original state.
-     * The problem is that `fread_func` can only return
-     * `upload_buffer_size` lengths. If the send we do here
-     * is larger and blocks, we do re-sending with smaller
-     * amounts of data and connection filters do not like
-     * that.
-     */
-    if(http && (sendsize > (size_t)data->set.upload_buffer_size))
-      sendsize = (size_t)data->set.upload_buffer_size;
-  }
-
-  result = Curl_xfer_send(data, ptr, sendsize, &amount);
-
-  if(!result) {
-    /*
-     * Note that we may not send the entire chunk at once, and we have a set
-     * number of data bytes at the end of the big buffer (out of which we may
-     * only send away a part).
-     */
-    /* how much of the header that was sent */
-    size_t headlen = (size_t)amount>headersize ? headersize : (size_t)amount;
-    size_t bodylen = amount - headlen;
-
-    /* this data _may_ contain binary stuff */
-    Curl_debug(data, CURLINFO_HEADER_OUT, ptr, headlen);
-    if(bodylen)
-      /* there was body data sent beyond the initial header part, pass that on
-         to the debug callback too */
-      Curl_debug(data, CURLINFO_DATA_OUT, ptr + headlen, bodylen);
-
-    /* 'amount' can never be a very large value here so typecasting it so a
-       signed 31 bit value should not cause problems even if ssize_t is
-       64bit */
-    *bytes_written += (long)amount;
-
-    if(http) {
-      /* if we sent a piece of the body here, up the byte counter for it
-         accordingly */
-      data->req.writebytecount += bodylen;
-      Curl_pgrsSetUploadCounter(data, data->req.writebytecount);
-
-      if((size_t)amount != size) {
-        /* The whole request could not be sent in one system call. We must
-           queue it up and send it later when we get the chance. We must not
-           loop here and wait until it might work again. */
-
-        size -= amount;
-
-        ptr = Curl_dyn_ptr(in) + amount;
-
-        /* backup the currently set pointers */
-        http->backup.fread_func = data->state.fread_func;
-        http->backup.fread_in = data->state.in;
-        http->backup.postdata = http->postdata;
-        http->backup.postsize = http->postsize;
-        http->backup.data = data;
-
-        /* set the new pointers for the request-sending */
-        data->state.fread_func = (curl_read_callback)readmoredata;
-        data->state.in = (void *)http;
-        http->postdata = ptr;
-        http->postsize = (curl_off_t)size;
-
-        /* this much data is remaining header: */
-        data->req.pendingheader = headersize - headlen;
-
-        http->send_buffer = *in; /* copy the whole struct */
-        http->sending = HTTPSEND_REQUEST;
-        return CURLE_OK;
-      }
-      http->sending = HTTPSEND_BODY;
-      /* the full buffer was sent, clean up and return */
-    }
-    else {
-      if((size_t)amount != size)
-        /* We have no continue-send mechanism now, fail. This can only happen
-           when this function is used from the CONNECT sending function. We
-           currently (stupidly) assume that the whole request is always sent
-           away in the first single chunk.
-
-           This needs FIXing.
-        */
-        return CURLE_SEND_ERROR;
-    }
-  }
-  Curl_dyn_free(in);
-
-  /* no remaining header data */
-  data->req.pendingheader = 0;
-  return result;
-}
-
-/* end of the add_buffer functions */
-/* ------------------------------------------------------------------------- */
-#else /* !USE_HYPER */
-  /* In hyper, this is an ugly NOP */
-#define buffer_send(a,b,c,d,e) CURLE_OK
-
-#endif /* !USE_HYPER(else) */
-
-
-
 /*
  * Curl_compareheader()
  *
@@ -1648,51 +1377,6 @@ enum proxy_use {
   HEADER_CONNECT  /* sending CONNECT to a proxy */
 };
 
-/* used to compile the provided trailers into one buffer
-   will return an error code if one of the headers is
-   not formatted correctly */
-CURLcode Curl_http_compile_trailers(struct curl_slist *trailers,
-                                    struct dynbuf *b,
-                                    struct Curl_easy *handle)
-{
-  char *ptr = NULL;
-  CURLcode result = CURLE_OK;
-  const char *endofline_native = NULL;
-  const char *endofline_network = NULL;
-
-  if(
-#ifdef CURL_DO_LINEEND_CONV
-     (handle->state.prefer_ascii) ||
-#endif
-     (handle->set.crlf)) {
-    /* \n will become \r\n later on */
-    endofline_native  = "\n";
-    endofline_network = "\x0a";
-  }
-  else {
-    endofline_native  = "\r\n";
-    endofline_network = "\x0d\x0a";
-  }
-
-  while(trailers) {
-    /* only add correctly formatted trailers */
-    ptr = strchr(trailers->data, ':');
-    if(ptr && *(ptr + 1) == ' ') {
-      result = Curl_dyn_add(b, trailers->data);
-      if(result)
-        return result;
-      result = Curl_dyn_add(b, endofline_native);
-      if(result)
-        return result;
-    }
-    else
-      infof(handle, "Malformatted trailing header, skipping trailer");
-    trailers = trailers->next;
-  }
-  result = Curl_dyn_add(b, endofline_network);
-  return result;
-}
-
 static bool hd_name_eq(const char *n1, size_t n1len,
                        const char *n2, size_t n2len)
 {
@@ -2461,13 +2145,9 @@ static CURLcode addexpect(struct Curl_easy *data, struct dynbuf *r)
   return CURLE_OK;
 }
 
-CURLcode Curl_http_req_send(struct Curl_easy *data,
-                            struct dynbuf *r, Curl_HttpReq httpreq)
+CURLcode Curl_http_req_complete(struct Curl_easy *data,
+                                struct dynbuf *r, Curl_HttpReq httpreq)
 {
-#ifndef USE_HYPER
-  /* Hyper always handles the body separately */
-  curl_off_t included_body = 0;
-#endif
   CURLcode result = CURLE_OK;
   struct HTTP *http = data->req.p.http;
 
@@ -2487,32 +2167,24 @@ CURLcode Curl_http_req_send(struct Curl_easy *data,
       result = Curl_dyn_addf(r, "Content-Length: %" CURL_FORMAT_CURL_OFF_T
                              "\r\n", http->postsize);
       if(result)
-        return result;
+        goto out;
     }
 
     result = addexpect(data, r);
     if(result)
-      return result;
+      goto out;
 
     /* end of headers */
     result = Curl_dyn_addn(r, STRCONST("\r\n"));
     if(result)
-      return result;
+      goto out;
 
     /* set the upload size to the progress meter */
     Curl_pgrsSetUploadSize(data, http->postsize);
-
-    /* this sends the buffer and frees all the buffer resources */
-    result = buffer_send(r, data, data->req.p.http,
-                         &data->info.request_size, 0);
-    if(result)
-      failf(data, "Failed sending PUT request");
+    if(!http->postsize)
+      result = Client_reader_set_null(data);
     else
-      /* prepare for transfer */
-      Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE,
-                      http->postsize?FIRSTSOCKET:-1);
-    if(result)
-      return result;
+      result = Client_reader_set_fread(data, data->state.infilesize);
     break;
 
 #if !defined(CURL_DISABLE_MIME) || !defined(CURL_DISABLE_FORM_API)
@@ -2522,16 +2194,12 @@ CURLcode Curl_http_req_send(struct Curl_easy *data,
     if(data->req.authneg) {
       /* nothing to post! */
       result = Curl_dyn_addn(r, STRCONST("Content-Length: 0\r\n\r\n"));
+      if(!result)
+        result = Client_reader_set_null(data);
       if(result)
         return result;
-
-      result = buffer_send(r, data, data->req.p.http,
-                           &data->info.request_size, 0);
-      if(result)
-        failf(data, "Failed sending POST request");
-      else
-        /* setup variables for the upcoming transfer */
-        Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, -1);
+      /* setup variables for the upcoming transfer */
+      Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, -1);
       break;
     }
 
@@ -2548,7 +2216,7 @@ CURLcode Curl_http_req_send(struct Curl_easy *data,
                              "Content-Length: %" CURL_FORMAT_CURL_OFF_T
                              "\r\n", http->postsize);
       if(result)
-        return result;
+        goto out;
     }
 
 #ifndef CURL_DISABLE_MIME
@@ -2559,40 +2227,32 @@ CURLcode Curl_http_req_send(struct Curl_easy *data,
       for(hdr = data->state.mimepost->curlheaders; hdr; hdr = hdr->next) {
         result = Curl_dyn_addf(r, "%s\r\n", hdr->data);
         if(result)
-          return result;
+          goto out;
       }
     }
 #endif
 
     result = addexpect(data, r);
     if(result)
-      return result;
+      goto out;
 
     /* make the request end in a true CRLF */
     result = Curl_dyn_addn(r, STRCONST("\r\n"));
     if(result)
-      return result;
+      goto out;
 
     /* set the upload size to the progress meter */
     Curl_pgrsSetUploadSize(data, http->postsize);
-
-    /* Read from mime structure. */
-    data->state.fread_func = (curl_read_callback) Curl_mime_read;
-    data->state.in = (void *) data->state.mimepost;
+    if(!http->postsize)
+      result = Client_reader_set_null(data);
+    else {
+      /* Read from mime structure. We could do a special client reader
+       * for this, but replacing the callback seems to work fine. */
+      data->state.fread_func = (curl_read_callback) Curl_mime_read;
+      data->state.in = (void *) data->state.mimepost;
+      result = Client_reader_set_fread(data, data->state.infilesize);
+    }
     http->sending = HTTPSEND_BODY;
-
-    /* this sends the buffer and frees all the buffer resources */
-    result = buffer_send(r, data, data->req.p.http,
-                         &data->info.request_size, 0);
-    if(result)
-      failf(data, "Failed sending POST request");
-    else
-      /* prepare for transfer */
-      Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE,
-                      http->postsize?FIRSTSOCKET:-1);
-    if(result)
-      return result;
-
     break;
 #endif
   case HTTPREQ_POST:
@@ -2615,147 +2275,53 @@ CURLcode Curl_http_req_send(struct Curl_easy *data,
       result = Curl_dyn_addf(r, "Content-Length: %" CURL_FORMAT_CURL_OFF_T
                              "\r\n", http->postsize);
       if(result)
-        return result;
+        goto out;
     }
 
     if(!Curl_checkheaders(data, STRCONST("Content-Type"))) {
       result = Curl_dyn_addn(r, STRCONST("Content-Type: application/"
                                          "x-www-form-urlencoded\r\n"));
       if(result)
-        return result;
+        goto out;
     }
 
     result = addexpect(data, r);
     if(result)
-      return result;
+      goto out;
 
-#ifndef USE_HYPER
-    /* With Hyper the body is always passed on separately */
-    if(data->set.postfields) {
-      if(!data->state.expect100header &&
-         (http->postsize < MAX_INITIAL_POST_SIZE)) {
-        /* if we don't use expect: 100  AND
-           postsize is less than MAX_INITIAL_POST_SIZE
-
-           then append the post data to the HTTP request header. This limit
-           is no magic limit but only set to prevent really huge POSTs to
-           get the data duplicated with malloc() and family. */
-
-        /* end of headers! */
-        result = Curl_dyn_addn(r, STRCONST("\r\n"));
-        if(result)
-          return result;
+    result = Curl_dyn_addn(r, STRCONST("\r\n"));
+    if(result)
+      goto out;
 
-        if(!data->req.upload_chunky) {
-          /* We're not sending it 'chunked', append it to the request
-             already now to reduce the number of send() calls */
-          result = Curl_dyn_addn(r, data->set.postfields,
-                                 (size_t)http->postsize);
-          included_body = http->postsize;
-        }
-        else {
-          if(http->postsize) {
-            char chunk[16];
-            /* Append the POST data chunky-style */
-            msnprintf(chunk, sizeof(chunk), "%x\r\n", (int)http->postsize);
-            result = Curl_dyn_add(r, chunk);
-            if(!result) {
-              included_body = http->postsize + strlen(chunk);
-              result = Curl_dyn_addn(r, data->set.postfields,
+    if(!http->postsize) {
+      Curl_pgrsSetUploadSize(data, -1);
+      result = Client_reader_set_null(data);
+    }
+    else if(data->set.postfields) {  /* we have the bytes */
+      Curl_pgrsSetUploadSize(data, http->postsize);
+      result = Client_reader_set_buf(data, data->set.postfields,
                                      (size_t)http->postsize);
-              if(!result)
-                result = Curl_dyn_addn(r, STRCONST("\r\n"));
-              included_body += 2;
-            }
-          }
-          if(!result) {
-            result = Curl_dyn_addn(r, STRCONST("\x30\x0d\x0a\x0d\x0a"));
-            /* 0  CR  LF  CR  LF */
-            included_body += 5;
-          }
-        }
-        if(result)
-          return result;
-        /* Make sure the progress information is accurate */
-        Curl_pgrsSetUploadSize(data, http->postsize);
-      }
-      else {
-        /* A huge POST coming up, do data separate from the request */
-        http->postdata = data->set.postfields;
-        http->sending = HTTPSEND_BODY;
-        http->backup.data = data;
-        data->state.fread_func = (curl_read_callback)readmoredata;
-        data->state.in = (void *)http;
-
-        /* set the upload size to the progress meter */
-        Curl_pgrsSetUploadSize(data, http->postsize);
-
-        /* end of headers! */
-        result = Curl_dyn_addn(r, STRCONST("\r\n"));
-        if(result)
-          return result;
-      }
     }
-    else
-#endif
-    {
-       /* end of headers! */
-      result = Curl_dyn_addn(r, STRCONST("\r\n"));
-      if(result)
-        return result;
-
-      if(data->req.upload_chunky && data->req.authneg) {
-        /* Chunky upload is selected and we're negotiating auth still, send
-           end-of-data only */
-        result = Curl_dyn_addn(r, (char *)STRCONST("\x30\x0d\x0a\x0d\x0a"));
-        /* 0  CR  LF  CR  LF */
-        if(result)
-          return result;
-      }
-
-      else if(data->state.infilesize) {
-        /* set the upload size to the progress meter */
-        Curl_pgrsSetUploadSize(data, http->postsize?http->postsize:-1);
-
-        /* set the pointer to mark that we will send the post body using the
-           read callback, but only if we're not in authenticate negotiation */
-        if(!data->req.authneg)
-          http->postdata = (char *)&http->postdata;
-      }
+    else { /* we read the bytes from the callback */
+      Curl_pgrsSetUploadSize(data, http->postsize);
+      result = Client_reader_set_fread(data, http->postsize);
     }
-    /* issue the request */
-    result = buffer_send(r, data, data->req.p.http,
-                         &data->info.request_size, included_body);
-
-    if(result)
-      failf(data, "Failed sending HTTP POST request");
-    else
-      Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE,
-                      http->postdata?FIRSTSOCKET:-1);
+    http->sending = HTTPSEND_BODY;
     break;
 
   default:
+    /* HTTP GET/HEAD download, has no body, needs no Content-Length */
     result = Curl_dyn_addn(r, STRCONST("\r\n"));
-    if(result)
-      return result;
-
-    /* issue the request */
-    result = Curl_req_send_hds(data, Curl_dyn_ptr(r), Curl_dyn_len(r));
-    Curl_dyn_free(r);
-    if(result)
-      failf(data, "Failed sending HTTP request");
-#ifdef USE_WEBSOCKETS
-    else if((data->conn->handler->protocol & (CURLPROTO_WS|CURLPROTO_WSS)) &&
-            !(data->set.connect_only))
-      /* Set up the transfer for two-way since without CONNECT_ONLY set, this
-         request probably wants to send data too post upgrade */
-      Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, FIRSTSOCKET);
-#endif
-    else
-      /* HTTP GET/HEAD download: */
-      Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, -1);
+    if(!result)
+      result = Client_reader_set_null(data);
+    break;
   }
 
+out:
+  if(!result) {
+    /* setup variables for the upcoming transfer */
+    Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, FIRSTSOCKET);
+  }
   return result;
 }
 
@@ -3320,17 +2886,15 @@ CURLcode Curl_http(struct Curl_easy *data, bool *done)
       Curl_pgrsSetUploadSize(data, 0); /* nothing */
 
     /* req_send takes ownership of the 'req' memory on success */
-    result = Curl_http_req_send(data, &req, httpreq);
+    result = Curl_http_req_complete(data, &req, httpreq);
+    if(!result && data->req.upload_chunky)
+      result = Curl_httpchunk_add_reader(data);
+    if(!result)
+      result = Curl_req_send(data, &req);
   }
-  if(result) {
-    Curl_dyn_free(&req);
+  Curl_dyn_free(&req);
+  if(result)
     goto fail;
-  }
-
-  if((http->postsize > -1) &&
-     (http->postsize <= data->req.writebytecount) &&
-     (http->sending != HTTPSEND_REQUEST))
-    data->req.upload_done = TRUE;
 
   if(data->req.writebytecount) {
     /* if a request-body has been sent off, we make sure this progress is noted

lib/http.h

@@ -94,10 +94,6 @@ CURLcode Curl_dynhds_add_custom(struct Curl_easy *data,
                                 bool is_connect,
                                 struct dynhds *hds);
 
-CURLcode Curl_http_compile_trailers(struct curl_slist *trailers,
-                                    struct dynbuf *buf,
-                                    struct Curl_easy *handle);
-
 void Curl_http_method(struct Curl_easy *data, struct connectdata *conn,
                       const char **method, Curl_HttpReq *);
 CURLcode Curl_http_useragent(struct Curl_easy *data);
@@ -112,8 +108,8 @@ CURLcode Curl_transferencode(struct Curl_easy *data);
 CURLcode Curl_http_body(struct Curl_easy *data, struct connectdata *conn,
                         Curl_HttpReq httpreq,
                         const char **teep);
-CURLcode Curl_http_req_send(struct Curl_easy *data,
-                            struct dynbuf *r, Curl_HttpReq httpreq);
+CURLcode Curl_http_req_complete(struct Curl_easy *data,
+                                struct dynbuf *r, Curl_HttpReq httpreq);
 bool Curl_use_http_1_1plus(const struct Curl_easy *data,
                            const struct connectdata *conn);
 #ifndef CURL_DISABLE_COOKIES

lib/http_chunks.c

@@ -27,10 +27,12 @@
 #ifndef CURL_DISABLE_HTTP
 
 #include "urldata.h" /* it includes http_chunks.h */
+#include "curl_printf.h"
 #include "sendf.h"   /* for the client write stuff */
 #include "dynbuf.h"
 #include "content_encoding.h"
 #include "http.h"
+#include "multiif.h"
 #include "strtoofft.h"
 #include "warnless.h"
 
@@ -458,4 +460,193 @@ const struct Curl_cwtype Curl_httpchunk_unencoder = {
   sizeof(struct chunked_writer)
 };
 
+/* max length of a HTTP chunk that we want to generate */
+#define CURL_CHUNKED_MINLEN   (1024)
+#define CURL_CHUNKED_MAXLEN   (64 * 1024)
+
+struct chunked_reader {
+  struct Curl_creader super;
+  struct bufq chunkbuf;
+  BIT(read_eos);  /* we read an EOS from the next reader */
+  BIT(eos);       /* we have returned an EOS */
+};
+
+static CURLcode cr_chunked_init(struct Curl_easy *data,
+                                struct Curl_creader *reader)
+{
+  struct chunked_reader *ctx = (struct chunked_reader *)reader;
+  (void)data;
+  Curl_bufq_init2(&ctx->chunkbuf, CURL_CHUNKED_MAXLEN, 2, BUFQ_OPT_SOFT_LIMIT);
+  return CURLE_OK;
+}
+
+static void cr_chunked_close(struct Curl_easy *data,
+                             struct Curl_creader *reader)
+{
+  struct chunked_reader *ctx = (struct chunked_reader *)reader;
+  (void)data;
+  Curl_bufq_free(&ctx->chunkbuf);
+}
+
+static CURLcode add_last_chunk(struct Curl_easy *data,
+                               struct Curl_creader *reader)
+{
+  struct chunked_reader *ctx = (struct chunked_reader *)reader;
+  struct curl_slist *trailers = NULL, *tr;
+  CURLcode result;
+  size_t n;
+  int rc;
+
+  if(!data->set.trailer_callback) {
+    return Curl_bufq_cwrite(&ctx->chunkbuf, STRCONST("0\r\n\r\n"), &n);
+  }
+
+  result = Curl_bufq_cwrite(&ctx->chunkbuf, STRCONST("0\r\n"), &n);
+  if(result)
+    goto out;
+
+  Curl_set_in_callback(data, true);
+  rc = data->set.trailer_callback(&trailers, data->set.trailer_data);
+  Curl_set_in_callback(data, false);
+
+  if(rc != CURL_TRAILERFUNC_OK) {
+    failf(data, "operation aborted by trailing headers callback");
+    result = CURLE_ABORTED_BY_CALLBACK;
+    goto out;
+  }
+
+  for(tr = trailers; tr; tr = tr->next) {
+    /* only add correctly formatted trailers */
+    char *ptr = strchr(tr->data, ':');
+    if(!ptr || *(ptr + 1) != ' ') {
+      infof(data, "Malformatted trailing header, skipping trailer");
+      continue;
+    }
+
+    result = Curl_bufq_cwrite(&ctx->chunkbuf, tr->data,
+                              strlen(tr->data), &n);
+    if(!result)
+      result = Curl_bufq_cwrite(&ctx->chunkbuf, STRCONST("\r\n"), &n);
+    if(result)
+      goto out;
+  }
+
+  result = Curl_bufq_cwrite(&ctx->chunkbuf, STRCONST("\r\n"), &n);
+
+out:
+  curl_slist_free_all(trailers);
+  return result;
+}
+
+static CURLcode add_chunk(struct Curl_easy *data,
+                          struct Curl_creader *reader,
+                          char *buf, size_t blen)
+{
+  struct chunked_reader *ctx = (struct chunked_reader *)reader;
+  CURLcode result;
+  char tmp[CURL_CHUNKED_MINLEN];
+  size_t nread;
+  bool eos;
+
+  DEBUGASSERT(!ctx->read_eos);
+  blen = CURLMIN(blen, CURL_CHUNKED_MAXLEN); /* respect our buffer pref */
+  if(blen < sizeof(tmp)) {
+    /* small read, make a chunk of decent size */
+    buf = tmp;
+    blen = sizeof(tmp);
+  }
+  else {
+    /* larger read, make a chunk that will fit when read back */
+    blen -= (8 + 2 + 2); /* deduct max overhead, 8 hex + 2*crlf */
+  }
+
+  result = Curl_creader_read(data, reader->next, buf, blen, &nread, &eos);
+  if(result)
+    return result;
+  if(eos)
+    ctx->read_eos = TRUE;
+
+  if(nread) {
+    /* actually got bytes, wrap them into the chunkbuf */
+    char hd[11] = "";
+    int hdlen;
+    size_t n;
+
+    hdlen = msnprintf(hd, sizeof(hd), "%zx\r\n", nread);
+    if(hdlen <= 0)
+      return CURLE_READ_ERROR;
+    /* On a soft-limited bufq, we do not need to check that all was written */
+    result = Curl_bufq_cwrite(&ctx->chunkbuf, hd, hdlen, &n);
+    if(!result)
+      result = Curl_bufq_cwrite(&ctx->chunkbuf, buf, nread, &n);
+    if(!result)
+      result = Curl_bufq_cwrite(&ctx->chunkbuf, "\r\n", 2, &n);
+    if(result)
+      return result;
+  }
+
+  if(ctx->read_eos)
+    return add_last_chunk(data, reader);
+  return CURLE_OK;
+}
+
+static CURLcode cr_chunked_read(struct Curl_easy *data,
+                                struct Curl_creader *reader,
+                                char *buf, size_t blen,
+                                size_t *pnread, bool *peos)
+{
+  struct chunked_reader *ctx = (struct chunked_reader *)reader;
+  CURLcode result = CURLE_READ_ERROR;
+
+  *pnread = 0;
+  *peos = ctx->eos;
+
+  if(!ctx->eos) {
+    if(!ctx->read_eos && Curl_bufq_is_empty(&ctx->chunkbuf)) {
+      /* Still getting data form the next reader, buffer is empty */
+      result = add_chunk(data, reader, buf, blen);
+      if(result)
+        return result;
+    }
+
+    if(!Curl_bufq_is_empty(&ctx->chunkbuf)) {
+      result = Curl_bufq_cread(&ctx->chunkbuf, buf, blen, pnread);
+      if(!result && ctx->read_eos && Curl_bufq_is_empty(&ctx->chunkbuf)) {
+        /* no more data, read all, done. */
+        ctx->eos = TRUE;
+        *peos = TRUE;
+      }
+      return result;
+    }
+  }
+  /* We may get here, because we are done or because callbacks paused */
+  DEBUGASSERT(ctx->eos || !ctx->read_eos);
+  return CURLE_OK;
+}
+
+/* HTTP chunked Transfer-Encoding encoder */
+const struct Curl_crtype Curl_httpchunk_encoder = {
+  "chunked",
+  cr_chunked_init,
+  cr_chunked_read,
+  cr_chunked_close,
+  Curl_creader_def_needs_rewind,
+  sizeof(struct chunked_reader)
+};
+
+CURLcode Curl_httpchunk_add_reader(struct Curl_easy *data)
+{
+  struct Curl_creader *reader = NULL;
+  CURLcode result;
+
+  result = Curl_creader_create(&reader, data, &Curl_httpchunk_encoder,
+                               CURL_CR_TRANSFER_ENCODE);
+  if(!result)
+    result = Curl_creader_add(data, reader);
+
+  if(result && reader)
+    Curl_creader_free(data, reader);
+  return result;
+}
+
 #endif /* CURL_DISABLE_HTTP */

lib/http_chunks.h

@@ -133,6 +133,13 @@ bool Curl_httpchunk_is_done(struct Curl_easy *data, struct Curl_chunker *ch);
 
 extern const struct Curl_cwtype Curl_httpchunk_unencoder;
 
+extern const struct Curl_crtype Curl_httpchunk_encoder;
+
+/**
+ * Add a transfer-encoding "chunked" reader to the transfers reader stack
+ */
+CURLcode Curl_httpchunk_add_reader(struct Curl_easy *data);
+
 #endif /* !CURL_DISABLE_HTTP */
 
 #endif /* HEADER_CURL_HTTP_CHUNKS_H */

lib/request.c

@@ -27,6 +27,7 @@
 #include "urldata.h"
 #include "dynbuf.h"
 #include "doh.h"
+#include "multiif.h"
 #include "progress.h"
 #include "request.h"
 #include "sendf.h"
@@ -48,7 +49,7 @@ CURLcode Curl_req_start(struct SingleRequest *req,
                         struct Curl_easy *data)
 {
   req->start = Curl_now();
-  Curl_cw_reset(data);
+  Curl_client_reset(data);
   if(!req->sendbuf_init) {
     Curl_bufq_init2(&req->sendbuf, data->set.upload_buffer_size, 1,
                     BUFQ_OPT_SOFT_LIMIT);
@@ -72,7 +73,7 @@ CURLcode Curl_req_done(struct SingleRequest *req,
   (void)req;
   if(!aborted)
     (void)Curl_req_flush(data);
-  Curl_cw_reset(data);
+  Curl_client_reset(data);
   return CURLE_OK;
 }
 
@@ -85,7 +86,7 @@ void Curl_req_reset(struct SingleRequest *req, struct Curl_easy *data)
    * free this safely without leaks. */
   Curl_safefree(req->p.http);
   Curl_safefree(req->newurl);
-  Curl_cw_reset(data);
+  Curl_client_reset(data);
 
 #ifndef CURL_DISABLE_DOH
   if(req->doh) {
@@ -114,7 +115,7 @@ void Curl_req_free(struct SingleRequest *req, struct Curl_easy *data)
   Curl_safefree(req->newurl);
   if(req->sendbuf_init)
     Curl_bufq_free(&req->sendbuf);
-  Curl_cw_reset(data);
+  Curl_client_reset(data);
 
 #ifndef CURL_DISABLE_DOH
   if(req->doh) {
@@ -171,22 +172,6 @@ static CURLcode req_send(struct Curl_easy *data,
   return result;
 }
 
-static CURLcode req_send_buffer_add(struct Curl_easy *data,
-                                    const char *buf, size_t blen,
-                                    size_t hds_len)
-{
-  CURLcode result = CURLE_OK;
-  ssize_t n;
-  n = Curl_bufq_write(&data->req.sendbuf,
-                      (const unsigned char *)buf, blen, &result);
-  if(n < 0)
-    return result;
-  /* We rely on a SOFTLIMIT on sendbuf, so it can take all data in */
-  DEBUGASSERT((size_t)n == blen);
-  data->req.sendbuf_hds_len += hds_len;
-  return CURLE_OK;
-}
-
 static CURLcode req_send_buffer_flush(struct Curl_easy *data)
 {
   CURLcode result = CURLE_OK;
@@ -200,8 +185,19 @@ static CURLcode req_send_buffer_flush(struct Curl_easy *data)
       break;
 
     Curl_bufq_skip(&data->req.sendbuf, nwritten);
-    if(hds_len)
+    if(hds_len) {
       data->req.sendbuf_hds_len -= CURLMIN(hds_len, nwritten);
+      if(!data->req.sendbuf_hds_len) {
+        /* all request headers sent */
+        if(data->req.exp100 == EXP100_SENDING_REQUEST) {
+          /* We are now waiting for a reply from the server or
+           * a timeout on our side */
+          data->req.exp100 = EXP100_AWAITING_CONTINUE;
+          data->req.start100 = Curl_now();
+          Curl_expire(data, data->set.expect_100_timeout, EXPIRE_100_TIMEOUT);
+        }
+      }
+    }
     /* leave if we could not send all. Maybe network blocking or
      * speed limits on transfer */
     if(nwritten < blen)
@@ -228,9 +224,41 @@ CURLcode Curl_req_flush(struct Curl_easy *data)
   return CURLE_OK;
 }
 
-CURLcode Curl_req_send(struct Curl_easy *data,
-                       const char *buf, size_t blen,
-                       size_t hds_len)
+#ifndef USE_HYPER
+
+static CURLcode req_send_buffer_add(struct Curl_easy *data,
+                                    const char *buf, size_t blen,
+                                    size_t hds_len)
+{
+  CURLcode result = CURLE_OK;
+  ssize_t n;
+  n = Curl_bufq_write(&data->req.sendbuf,
+                      (const unsigned char *)buf, blen, &result);
+  if(n < 0)
+    return result;
+  /* We rely on a SOFTLIMIT on sendbuf, so it can take all data in */
+  DEBUGASSERT((size_t)n == blen);
+  data->req.sendbuf_hds_len += hds_len;
+  return CURLE_OK;
+}
+
+static ssize_t add_from_client(void *reader_ctx,
+                               unsigned char *buf, size_t buflen,
+                               CURLcode *err)
+{
+  struct Curl_easy *data = reader_ctx;
+  size_t nread;
+  bool eos;
+
+  *err = Curl_client_read(data, (char *)buf, buflen, &nread, &eos);
+  if(*err)
+    return -1;
+  if(eos)
+    data->req.eos_read = TRUE;
+  return (ssize_t)nread;
+}
+
+CURLcode Curl_req_send(struct Curl_easy *data, struct dynbuf *buf)
 {
   CURLcode result;
 
@@ -242,14 +270,25 @@ CURLcode Curl_req_send(struct Curl_easy *data,
    * important for TLS libraries that expect this.
    * We *could* optimized for non-TLS transfers, but that would mean
    * separate code paths and seems not worth it. */
-  result = req_send_buffer_add(data, buf, blen, hds_len);
+  result = req_send_buffer_add(data, Curl_dyn_ptr(buf), Curl_dyn_len(buf),
+                               Curl_dyn_len(buf));
   if(result)
     return result;
+
+  if((data->req.exp100 == EXP100_SEND_DATA) &&
+     !Curl_bufq_is_full(&data->req.sendbuf)) {
+    ssize_t nread = Curl_bufq_sipn(&data->req.sendbuf, 0,
+                                   add_from_client, data, &result);
+    if(nread < 0 && result != CURLE_AGAIN)
+      return result;
+  }
+
   result = req_send_buffer_flush(data);
   if(result == CURLE_AGAIN)
     result = CURLE_OK;
   return result;
 }
+#endif /* !USE_HYPER */
 
 bool Curl_req_want_send(struct Curl_easy *data)
 {

lib/request.h

@@ -64,8 +64,6 @@ struct SingleRequest {
   curl_off_t bytecount;         /* total number of bytes read */
   curl_off_t writebytecount;    /* number of bytes written */
 
-  size_t pendingheader;         /* this many bytes left to send is actually
-                                    header and not body */
   struct curltime start;         /* transfer started at this time */
   unsigned int headerbytecount;  /* received server headers (not CONNECT
                                     headers) */
@@ -87,9 +85,12 @@ struct SingleRequest {
   enum expect100 exp100;        /* expect 100 continue state */
   enum upgrade101 upgr101;      /* 101 upgrade state */
 
-  /* Client Writer stack, handles trasnfer- and content-encodings, protocol
+  /* Client Writer stack, handles transfer- and content-encodings, protocol
    * checks, pausing by client callbacks. */
   struct Curl_cwriter *writer_stack;
+  /* Client Reader stack, handles transfer- and content-encodings, protocol
+   * checks, pausing by client callbacks. */
+  struct Curl_creader *reader_stack;
   struct bufq sendbuf; /* data which needs to be send to the server */
   size_t sendbuf_hds_len; /* amount of header bytes in sendbuf */
   time_t timeofdoc;
@@ -137,6 +138,7 @@ struct SingleRequest {
   BIT(content_range); /* set TRUE if Content-Range: was found */
   BIT(download_done); /* set to TRUE when download is complete */
   BIT(eos_written);   /* iff EOS has been written to client */
+  BIT(eos_read);      /* iff EOS has been read from the client */
   BIT(upload_done);   /* set to TRUE when doing chunked transfer-encoding
                          upload and we're uploading the last chunk */
   BIT(ignorebody);    /* we read a response-body but we ignore it! */
@@ -190,24 +192,18 @@ void Curl_req_free(struct SingleRequest *req, struct Curl_easy *data);
  */
 void Curl_req_reset(struct SingleRequest *req, struct Curl_easy *data);
 
-
+#ifndef USE_HYPER
 /**
- * Send request bytes for transfer. If not all could be sent
+ * Send request headers. If not all could be sent
  * they will be buffered. Use `Curl_req_flush()` to make sure
  * bytes are really send.
  * @param data      the transfer making the request
- * @param buf       the bytes to send
- * @param blen      the number of bytes to send
- * @param hds_len   the number of bytes from the start that are headers
+ * @param buf       the complete header bytes, no body
  * @return CURLE_OK (on blocking with *pnwritten == 0) or error.
  */
-CURLcode Curl_req_send(struct Curl_easy *data,
-                        const char *buf, size_t blen,
-                        size_t hds_len);
+CURLcode Curl_req_send(struct Curl_easy *data, struct dynbuf *buf);
 
-/* Convenience for sending only header bytes */
-#define Curl_req_send_hds(data, buf, blen) \
-          Curl_req_send((data), (buf), (blen), (blen))
+#endif /* !USE_HYPER */
 
 /**
  * Flush all buffered request bytes.

lib/rtsp.c

@@ -241,6 +241,8 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
   const char *p_userpwd = NULL;
 
   *done = TRUE;
+  /* Initialize a dynamic send buffer */
+  Curl_dyn_init(&req_buffer, DYN_RTSP_REQ_HEADER);
 
   rtsp->CSeq_sent = data->state.rtsp_next_client_CSeq;
   rtsp->CSeq_recv = 0;
@@ -311,8 +313,7 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
 
   if(rtspreq == RTSPREQ_RECEIVE) {
     Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, -1);
-
-    return result;
+    goto out;
   }
 
   p_session_id = data->set.str[STRING_RTSP_SESSION_ID];
@@ -320,7 +321,8 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
      (rtspreq & ~(RTSPREQ_OPTIONS | RTSPREQ_DESCRIBE | RTSPREQ_SETUP))) {
     failf(data, "Refusing to issue an RTSP request [%s] without a session ID.",
           p_request);
-    return CURLE_BAD_FUNCTION_ARGUMENT;
+    result = CURLE_BAD_FUNCTION_ARGUMENT;
+    goto out;
   }
 
   /* Stream URI. Default to server '*' if not specified */
@@ -347,7 +349,8 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
     else {
       failf(data,
             "Refusing to issue an RTSP SETUP without a Transport: header.");
-      return CURLE_BAD_FUNCTION_ARGUMENT;
+      result = CURLE_BAD_FUNCTION_ARGUMENT;
+      goto out;
     }
 
     p_transport = data->state.aptr.rtsp_transport;
@@ -366,9 +369,10 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
       data->state.aptr.accept_encoding =
         aprintf("Accept-Encoding: %s\r\n", data->set.str[STRING_ENCODING]);
 
-      if(!data->state.aptr.accept_encoding)
-        return CURLE_OUT_OF_MEMORY;
-
+      if(!data->state.aptr.accept_encoding) {
+        result = CURLE_OUT_OF_MEMORY;
+        goto out;
+      }
       p_accept_encoding = data->state.aptr.accept_encoding;
     }
   }
@@ -390,7 +394,7 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
   result = Curl_http_output_auth(data, conn, p_request, HTTPREQ_GET,
                                  p_stream_uri, FALSE);
   if(result)
-    return result;
+    goto out;
 
   p_proxyuserpwd = data->state.aptr.proxyuserpwd;
   p_userpwd = data->state.aptr.userpwd;
@@ -424,23 +428,22 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
    */
   if(Curl_checkheaders(data, STRCONST("CSeq"))) {
     failf(data, "CSeq cannot be set as a custom header.");
-    return CURLE_RTSP_CSEQ_ERROR;
+    result = CURLE_RTSP_CSEQ_ERROR;
+    goto out;
   }
   if(Curl_checkheaders(data, STRCONST("Session"))) {
     failf(data, "Session ID cannot be set as a custom header.");
-    return CURLE_BAD_FUNCTION_ARGUMENT;
+    result = CURLE_BAD_FUNCTION_ARGUMENT;
+    goto out;
   }
 
-  /* Initialize a dynamic send buffer */
-  Curl_dyn_init(&req_buffer, DYN_RTSP_REQ_HEADER);
-
   result =
     Curl_dyn_addf(&req_buffer,
                   "%s %s RTSP/1.0\r\n" /* Request Stream-URI RTSP/1.0 */
                   "CSeq: %ld\r\n", /* CSeq */
                   p_request, p_stream_uri, rtsp->CSeq_sent);
   if(result)
-    return result;
+    goto out;
 
   /*
    * Rather than do a normal alloc line, keep the session_id unformatted
@@ -449,7 +452,7 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
   if(p_session_id) {
     result = Curl_dyn_addf(&req_buffer, "Session: %s\r\n", p_session_id);
     if(result)
-      return result;
+      goto out;
   }
 
   /*
@@ -481,17 +484,17 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
   Curl_safefree(data->state.aptr.userpwd);
 
   if(result)
-    return result;
+    goto out;
 
   if((rtspreq == RTSPREQ_SETUP) || (rtspreq == RTSPREQ_DESCRIBE)) {
     result = Curl_add_timecondition(data, &req_buffer);
     if(result)
-      return result;
+      goto out;
   }
 
   result = Curl_add_custom_headers(data, FALSE, &req_buffer);
   if(result)
-    return result;
+    goto out;
 
   if(rtspreq == RTSPREQ_ANNOUNCE ||
      rtspreq == RTSPREQ_SET_PARAMETER ||
@@ -500,13 +503,24 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
     if(data->state.upload) {
       putsize = data->state.infilesize;
       data->state.httpreq = HTTPREQ_PUT;
-
+      result = Client_reader_set_fread(data, putsize);
+      if(result)
+        goto out;
     }
     else {
       postsize = (data->state.infilesize != -1)?
         data->state.infilesize:
         (data->set.postfields? (curl_off_t)strlen(data->set.postfields):0);
       data->state.httpreq = HTTPREQ_POST;
+      if(postsize > 0 && data->set.postfields)
+        result = Client_reader_set_buf(data, data->set.postfields,
+                                       (size_t)postsize);
+      else if(!postsize)
+        result = Client_reader_set_null(data);
+      else
+        result = Client_reader_set_fread(data, postsize);
+      if(result)
+        goto out;
     }
 
     if(putsize > 0 || postsize > 0) {
@@ -518,7 +532,7 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
                         "Content-Length: %" CURL_FORMAT_CURL_OFF_T"\r\n",
                         (data->state.upload ? putsize : postsize));
         if(result)
-          return result;
+          goto out;
       }
 
       if(rtspreq == RTSPREQ_SET_PARAMETER ||
@@ -528,7 +542,7 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
                                  STRCONST("Content-Type: "
                                           "text/parameters\r\n"));
           if(result)
-            return result;
+            goto out;
         }
       }
 
@@ -538,7 +552,7 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
                                  STRCONST("Content-Type: "
                                           "application/sdp\r\n"));
           if(result)
-            return result;
+            goto out;
         }
       }
 
@@ -550,31 +564,27 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
       data->req.no_body = TRUE;
     }
   }
+  else {
+    result = Client_reader_set_null(data);
+    if(result)
+      goto out;
+  }
 
   /* RTSP never allows chunked transfer */
   data->req.forbidchunk = TRUE;
   /* Finish the request buffer */
   result = Curl_dyn_addn(&req_buffer, STRCONST("\r\n"));
   if(result)
-    return result;
-
-  if(postsize > 0) {
-    result = Curl_dyn_addn(&req_buffer, data->set.postfields,
-                           (size_t)postsize);
-    if(result)
-      return result;
-  }
+    goto out;
 
   /* issue the request */
-  result = Curl_req_send_hds(data, Curl_dyn_ptr(&req_buffer),
-                             Curl_dyn_len(&req_buffer));
-  Curl_dyn_free(&req_buffer);
+  result = Curl_req_send(data, &req_buffer);
   if(result) {
     failf(data, "Failed sending RTSP request");
-    return result;
+    goto out;
   }
 
-  Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, putsize?FIRSTSOCKET:-1);
+  Curl_xfer_setup(data, FIRSTSOCKET, -1, TRUE, FIRSTSOCKET);
 
   /* Increment the CSeq on success */
   data->state.rtsp_next_client_CSeq++;
@@ -586,7 +596,8 @@ static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
     if(Curl_pgrsUpdate(data))
       result = CURLE_ABORTED_BY_CALLBACK;
   }
-
+out:
+  Curl_dyn_free(&req_buffer);
   return result;
 }
 

lib/sendf.c

@@ -59,7 +59,7 @@
 #include "memdebug.h"
 
 
-static CURLcode do_init_stack(struct Curl_easy *data);
+static CURLcode do_init_writer_stack(struct Curl_easy *data);
 
 /* Curl_client_write() sends data to the write callback(s)
 
@@ -81,7 +81,7 @@ CURLcode Curl_client_write(struct Curl_easy *data,
               ((type & ~(CLIENTWRITE_INFO|CLIENTWRITE_EOS)) == 0));
 
   if(!data->req.writer_stack) {
-    result = do_init_stack(data);
+    result = do_init_writer_stack(data);
     if(result)
       return result;
     DEBUGASSERT(data->req.writer_stack);
@@ -90,16 +90,33 @@ CURLcode Curl_client_write(struct Curl_easy *data,
   return Curl_cwriter_write(data, data->req.writer_stack, type, buf, blen);
 }
 
-void Curl_cw_reset(struct Curl_easy *data)
+static void cl_reset_writer(struct Curl_easy *data)
 {
   struct Curl_cwriter *writer = data->req.writer_stack;
-
   while(writer) {
     data->req.writer_stack = writer->next;
     writer->cwt->do_close(data, writer);
     free(writer);
     writer = data->req.writer_stack;
   }
+}
+
+static void cl_reset_reader(struct Curl_easy *data)
+{
+  struct Curl_creader *reader = data->req.reader_stack;
+  while(reader) {
+    data->req.reader_stack = reader->next;
+    reader->crt->do_close(data, reader);
+    free(reader);
+    reader = data->req.reader_stack;
+  }
+}
+
+void Curl_client_reset(struct Curl_easy *data)
+{
+  DEBUGF(infof(data, "Curl_client_reset()"));
+  cl_reset_reader(data);
+  cl_reset_writer(data);
 
   data->req.bytecount = 0;
   data->req.headerline = 0;
@@ -338,7 +355,7 @@ size_t Curl_cwriter_count(struct Curl_easy *data, Curl_cwriter_phase phase)
   return n;
 }
 
-static CURLcode do_init_stack(struct Curl_easy *data)
+static CURLcode do_init_writer_stack(struct Curl_easy *data)
 {
   struct Curl_cwriter *writer;
   CURLcode result;
@@ -374,7 +391,7 @@ CURLcode Curl_cwriter_add(struct Curl_easy *data,
   struct Curl_cwriter **anchor = &data->req.writer_stack;
 
   if(!*anchor) {
-    result = do_init_stack(data);
+    result = do_init_writer_stack(data);
     if(result)
       return result;
   }
@@ -426,3 +443,502 @@ void Curl_cwriter_remove_by_name(struct Curl_easy *data,
   }
 }
 
+CURLcode Curl_creader_read(struct Curl_easy *data,
+                           struct Curl_creader *reader,
+                           char *buf, size_t blen, size_t *nread, bool *eos)
+{
+  if(!reader)
+    return CURLE_READ_ERROR;
+  return reader->crt->do_read(data, reader, buf, blen, nread, eos);
+}
+
+CURLcode Curl_creader_def_init(struct Curl_easy *data,
+                               struct Curl_creader *reader)
+{
+  (void)data;
+  (void)reader;
+  return CURLE_OK;
+}
+
+void Curl_creader_def_close(struct Curl_easy *data,
+                            struct Curl_creader *reader)
+{
+  (void)data;
+  (void)reader;
+}
+
+bool Curl_creader_def_needs_rewind(struct Curl_easy *data,
+                                   struct Curl_creader *reader)
+{
+  (void)data;
+  (void)reader;
+  return FALSE;
+}
+
+struct cr_in_ctx {
+  struct Curl_creader super;
+  curl_off_t total_len;
+  curl_off_t read_len;
+  CURLcode error_result;
+  BIT(seen_eos);
+  BIT(errored);
+  BIT(has_used_cb);
+};
+
+static CURLcode cr_in_init(struct Curl_easy *data, struct Curl_creader *reader)
+{
+  struct cr_in_ctx *ctx = (struct cr_in_ctx *)reader;
+  (void)data;
+  ctx->total_len = -1;
+  ctx->read_len = 0;
+  return CURLE_OK;
+}
+
+/* Real client reader to installed client callbacks. */
+static CURLcode cr_in_read(struct Curl_easy *data,
+                           struct Curl_creader *reader,
+                           char *buf, size_t blen,
+                           size_t *pnread, bool *peos)
+{
+  struct cr_in_ctx *ctx = (struct cr_in_ctx *)reader;
+  size_t nread;
+
+  /* Once we have errored, we will return the same error forever */
+  if(ctx->errored) {
+    *pnread = 0;
+    *peos = FALSE;
+    return ctx->error_result;
+  }
+  if(ctx->seen_eos) {
+    *pnread = 0;
+    *peos = TRUE;
+    return CURLE_OK;
+  }
+  /* respect length limitations */
+  if(ctx->total_len >= 0) {
+    curl_off_t remain = ctx->total_len - ctx->read_len;
+    if(remain <= 0)
+      blen = 0;
+    else if(remain < (curl_off_t)blen)
+      blen = (size_t)remain;
+  }
+  nread = 0;
+  if(data->state.fread_func && blen) {
+    Curl_set_in_callback(data, true);
+    nread = data->state.fread_func(buf, 1, blen, data->state.in);
+    Curl_set_in_callback(data, false);
+    ctx->has_used_cb = TRUE;
+  }
+
+  switch(nread) {
+  case 0:
+    if((ctx->total_len >= 0) && (ctx->read_len < ctx->total_len)) {
+      failf(data, "client read function EOF fail, only "
+            "only %"CURL_FORMAT_CURL_OFF_T"/%"CURL_FORMAT_CURL_OFF_T
+            " of needed bytes read", ctx->read_len, ctx->total_len);
+      return CURLE_READ_ERROR;
+    }
+    *pnread = 0;
+    *peos = TRUE;
+    ctx->seen_eos = TRUE;
+    break;
+
+  case CURL_READFUNC_ABORT:
+    failf(data, "operation aborted by callback");
+    *pnread = 0;
+    *peos = FALSE;
+    ctx->errored = TRUE;
+    ctx->error_result = CURLE_ABORTED_BY_CALLBACK;
+    return CURLE_ABORTED_BY_CALLBACK;
+
+  case CURL_READFUNC_PAUSE:
+    if(data->conn->handler->flags & PROTOPT_NONETWORK) {
+      /* protocols that work without network cannot be paused. This is
+         actually only FILE:// just now, and it can't pause since the transfer
+         isn't done using the "normal" procedure. */
+      failf(data, "Read callback asked for PAUSE when not supported");
+      return CURLE_READ_ERROR;
+    }
+    /* CURL_READFUNC_PAUSE pauses read callbacks that feed socket writes */
+    data->req.keepon |= KEEP_SEND_PAUSE; /* mark socket send as paused */
+    *pnread = 0;
+    *peos = FALSE;
+    break; /* nothing was read */
+
+  default:
+    if(nread > blen) {
+      /* the read function returned a too large value */
+      failf(data, "read function returned funny value");
+      *pnread = 0;
+      *peos = FALSE;
+      ctx->errored = TRUE;
+      ctx->error_result = CURLE_READ_ERROR;
+      return CURLE_READ_ERROR;
+    }
+    ctx->read_len += nread;
+    *pnread = nread;
+    *peos = FALSE;
+    break;
+  }
+  DEBUGF(infof(data, "cr_in_read(len=%zu, total=%"CURL_FORMAT_CURL_OFF_T
+         ", read=%"CURL_FORMAT_CURL_OFF_T") -> %d, %zu, %d",
+         blen, ctx->total_len, ctx->read_len, CURLE_OK, *pnread, *peos));
+  return CURLE_OK;
+}
+
+static bool cr_in_needs_rewind(struct Curl_easy *data,
+                               struct Curl_creader *reader)
+{
+  struct cr_in_ctx *ctx = (struct cr_in_ctx *)reader;
+  (void)data;
+  return ctx->has_used_cb;
+}
+
+static const struct Curl_crtype cr_in = {
+  "cr-in",
+  cr_in_init,
+  cr_in_read,
+  Curl_creader_def_close,
+  cr_in_needs_rewind,
+  sizeof(struct cr_in_ctx)
+};
+
+CURLcode Curl_creader_create(struct Curl_creader **preader,
+                             struct Curl_easy *data,
+                             const struct Curl_crtype *crt,
+                             Curl_creader_phase phase)
+{
+  struct Curl_creader *reader;
+  CURLcode result = CURLE_OUT_OF_MEMORY;
+
+  DEBUGASSERT(crt->creader_size >= sizeof(struct Curl_creader));
+  reader = (struct Curl_creader *) calloc(1, crt->creader_size);
+  if(!reader)
+    goto out;
+
+  reader->crt = crt;
+  reader->phase = phase;
+  result = crt->do_init(data, reader);
+
+out:
+  *preader = result? NULL : reader;
+  if(result)
+    free(reader);
+  return result;
+}
+
+void Curl_creader_free(struct Curl_easy *data, struct Curl_creader *reader)
+{
+  if(reader) {
+    reader->crt->do_close(data, reader);
+    free(reader);
+  }
+}
+
+struct cr_lc_ctx {
+  struct Curl_creader super;
+  struct bufq buf;
+  BIT(read_eos);  /* we read an EOS from the next reader */
+  BIT(eos);       /* we have returned an EOS */
+};
+
+static CURLcode cr_lc_init(struct Curl_easy *data, struct Curl_creader *reader)
+{
+  struct cr_lc_ctx *ctx = (struct cr_lc_ctx *)reader;
+  (void)data;
+  Curl_bufq_init2(&ctx->buf, (16 * 1024), 1, BUFQ_OPT_SOFT_LIMIT);
+  return CURLE_OK;
+}
+
+static void cr_lc_close(struct Curl_easy *data, struct Curl_creader *reader)
+{
+  struct cr_lc_ctx *ctx = (struct cr_lc_ctx *)reader;
+  (void)data;
+  Curl_bufq_free(&ctx->buf);
+}
+
+/* client reader doing line end conversions. */
+static CURLcode cr_lc_read(struct Curl_easy *data,
+                           struct Curl_creader *reader,
+                           char *buf, size_t blen,
+                           size_t *pnread, bool *peos)
+{
+  struct cr_lc_ctx *ctx = (struct cr_lc_ctx *)reader;
+  CURLcode result;
+  size_t nread, i, start, n;
+  bool eos;
+
+  if(ctx->eos) {
+    *pnread = 0;
+    *peos = TRUE;
+    return CURLE_OK;
+  }
+
+  if(Curl_bufq_is_empty(&ctx->buf)) {
+    if(ctx->read_eos) {
+      ctx->eos = TRUE;
+      *pnread = 0;
+      *peos = TRUE;
+      return CURLE_OK;
+    }
+    /* Still getting data form the next reader, ctx->buf is empty */
+    result = Curl_creader_read(data, reader->next, buf, blen, &nread, &eos);
+    if(result)
+      return result;
+    ctx->read_eos = eos;
+
+    if(!nread || !memchr(buf, '\n', nread)) {
+      /* nothing to convert, return this right away */
+      if(ctx->read_eos)
+        ctx->eos = TRUE;
+      *pnread = nread;
+      *peos = ctx->eos;
+      return CURLE_OK;
+    }
+
+    /* at least one \n needs conversion to '\r\n', place into ctx->buf */
+    for(i = start = 0; i < nread; ++i) {
+      if(buf[i] != '\n')
+        continue;
+      /* on a soft limit bufq, we do not need to check length */
+      result = Curl_bufq_cwrite(&ctx->buf, buf + start, i - start, &n);
+      if(!result)
+        result = Curl_bufq_cwrite(&ctx->buf, STRCONST("\r\n"), &n);
+      if(result)
+        return result;
+      start = i + 1;
+      if(!data->set.crlf && (data->state.infilesize != -1)) {
+        /* we're here only because FTP is in ASCII mode...
+           bump infilesize for the LF we just added */
+        data->state.infilesize++;
+        /* comment: this might work for FTP, but in HTTP we could not change
+         * the content length after having started the request... */
+      }
+    }
+  }
+
+  DEBUGASSERT(!Curl_bufq_is_empty(&ctx->buf));
+  *peos = FALSE;
+  result = Curl_bufq_cread(&ctx->buf, buf, blen, pnread);
+  if(!result && ctx->read_eos && Curl_bufq_is_empty(&ctx->buf)) {
+    /* no more data, read all, done. */
+    ctx->eos = TRUE;
+    *peos = TRUE;
+  }
+  return result;
+}
+
+static const struct Curl_crtype cr_lc = {
+  "cr-lineconv",
+  cr_lc_init,
+  cr_lc_read,
+  cr_lc_close,
+  Curl_creader_def_needs_rewind,
+  sizeof(struct cr_lc_ctx)
+};
+
+static CURLcode cr_lc_add(struct Curl_easy *data)
+{
+  struct Curl_creader *reader = NULL;
+  CURLcode result;
+
+  result = Curl_creader_create(&reader, data, &cr_lc,
+                               CURL_CR_TRANSFER_ENCODE);
+  if(!result)
+    result = Curl_creader_add(data, reader);
+
+  if(result && reader)
+    Curl_creader_free(data, reader);
+  return result;
+}
+
+static CURLcode do_init_reader_stack(struct Curl_easy *data,
+                                     const struct Curl_crtype *crt,
+                                     struct Curl_creader **preader)
+{
+  CURLcode result;
+
+  DEBUGASSERT(!data->req.reader_stack);
+  result = Curl_creader_create(preader, data, crt, CURL_CR_CLIENT);
+  if(result)
+    return result;
+  data->req.reader_stack = *preader;
+
+  if(data->set.crlf
+#ifdef CURL_DO_LINEEND_CONV
+     || data->state.prefer_ascii
+#endif
+    ) {
+    result = cr_lc_add(data);
+    if(result)
+      return result;
+  }
+
+  return result;
+}
+
+CURLcode Client_reader_set_fread(struct Curl_easy *data, curl_off_t len)
+{
+  CURLcode result;
+  struct Curl_creader *r;
+
+  cl_reset_reader(data);
+  result = do_init_reader_stack(data, &cr_in, &r);
+  if(!result && r) {
+    struct cr_in_ctx *ctx = (struct cr_in_ctx *)r;
+    DEBUGASSERT(r->crt == &cr_in);
+    ctx->total_len = len;
+  }
+  return result;
+}
+
+CURLcode Curl_creader_add(struct Curl_easy *data,
+                          struct Curl_creader *reader)
+{
+  CURLcode result;
+  struct Curl_creader **anchor = &data->req.reader_stack;
+
+  if(!*anchor) {
+    result = Client_reader_set_fread(data, data->state.infilesize);
+    if(result)
+      return result;
+  }
+
+  /* Insert the writer as first in its phase.
+   * Skip existing readers of lower phases. */
+  while(*anchor && (*anchor)->phase < reader->phase)
+    anchor = &((*anchor)->next);
+  reader->next = *anchor;
+  *anchor = reader;
+  return CURLE_OK;
+}
+
+CURLcode Curl_client_read(struct Curl_easy *data, char *buf, size_t blen,
+                          size_t *nread, bool *eos)
+{
+  CURLcode result;
+
+  DEBUGASSERT(buf);
+  DEBUGASSERT(blen);
+  DEBUGASSERT(nread);
+  DEBUGASSERT(eos);
+
+  if(!data->req.reader_stack) {
+    result = Client_reader_set_fread(data, data->state.infilesize);
+    if(result)
+      return result;
+    DEBUGASSERT(data->req.reader_stack);
+  }
+
+  result = Curl_creader_read(data, data->req.reader_stack, buf, blen,
+                             nread, eos);
+  return result;
+}
+
+bool Curl_client_read_needs_rewind(struct Curl_easy *data)
+{
+  struct Curl_creader *reader = data->req.reader_stack;
+  while(reader) {
+    if(reader->crt->needs_rewind(data, reader))
+      return TRUE;
+    reader = reader->next;
+  }
+  return FALSE;
+}
+
+static CURLcode cr_null_read(struct Curl_easy *data,
+                             struct Curl_creader *reader,
+                             char *buf, size_t blen,
+                             size_t *pnread, bool *peos)
+{
+  (void)data;
+  (void)reader;
+  (void)buf;
+  (void)blen;
+  *pnread = 0;
+  *peos = TRUE;
+  return CURLE_OK;
+}
+
+static const struct Curl_crtype cr_null = {
+  "cr-null",
+  Curl_creader_def_init,
+  cr_null_read,
+  Curl_creader_def_close,
+  Curl_creader_def_needs_rewind,
+  sizeof(struct Curl_creader)
+};
+
+CURLcode Client_reader_set_null(struct Curl_easy *data)
+{
+  struct Curl_creader *r;
+
+  cl_reset_reader(data);
+  return do_init_reader_stack(data, &cr_null, &r);
+}
+
+struct cr_buf_ctx {
+  struct Curl_creader super;
+  const char *buf;
+  size_t blen;
+  size_t index;
+};
+
+static CURLcode cr_buf_read(struct Curl_easy *data,
+                            struct Curl_creader *reader,
+                            char *buf, size_t blen,
+                            size_t *pnread, bool *peos)
+{
+  struct cr_buf_ctx *ctx = (struct cr_buf_ctx *)reader;
+  size_t nread = ctx->blen - ctx->index;
+
+  (void)data;
+  if(!nread || !ctx->buf) {
+    *pnread = 0;
+    *peos = TRUE;
+  }
+  else {
+    if(nread > blen)
+      nread = blen;
+    memcpy(buf, ctx->buf + ctx->index, nread);
+    *pnread = nread;
+    ctx->index += nread;
+    *peos = (ctx->index == ctx->blen);
+  }
+  return CURLE_OK;
+}
+
+static bool cr_buf_needs_rewind(struct Curl_easy *data,
+                                struct Curl_creader *reader)
+{
+  struct cr_buf_ctx *ctx = (struct cr_buf_ctx *)reader;
+  (void)data;
+  return ctx->index > 0;
+}
+
+static const struct Curl_crtype cr_buf = {
+  "cr-buf",
+  Curl_creader_def_init,
+  cr_buf_read,
+  Curl_creader_def_close,
+  cr_buf_needs_rewind,
+  sizeof(struct cr_buf_ctx)
+};
+
+CURLcode Client_reader_set_buf(struct Curl_easy *data,
+                               const char *buf, size_t blen)
+{
+  CURLcode result;
+  struct Curl_creader *r;
+
+  cl_reset_reader(data);
+  result = do_init_reader_stack(data, &cr_buf, &r);
+  if(!result && r) {
+    struct cr_buf_ctx *ctx = (struct cr_buf_ctx *)r;
+    DEBUGASSERT(r->crt == &cr_buf);
+    ctx->buf = buf;
+    ctx->blen = blen;
+    ctx->index = 0;
+  }
+  return result;
+}

lib/sendf.h

@@ -61,7 +61,7 @@ CURLcode Curl_client_write(struct Curl_easy *data, int type, const char *ptr,
 /**
  * Free all resources related to client writing.
  */
-void Curl_cw_reset(struct Curl_easy *data);
+void Curl_client_reset(struct Curl_easy *data);
 
 /**
  * Client Writers - a chain passing transfer BODY data to the client.
@@ -175,4 +175,107 @@ void Curl_cwriter_def_close(struct Curl_easy *data,
                             struct Curl_cwriter *writer);
 
 
+/* Client Reader Type, provides the implementation */
+struct Curl_crtype {
+  const char *name;        /* writer name. */
+  CURLcode (*do_init)(struct Curl_easy *data, struct Curl_creader *writer);
+  CURLcode (*do_read)(struct Curl_easy *data, struct Curl_creader *reader,
+                      char *buf, size_t blen, size_t *nread, bool *eos);
+  void (*do_close)(struct Curl_easy *data, struct Curl_creader *reader);
+  bool (*needs_rewind)(struct Curl_easy *data, struct Curl_creader *reader);
+  size_t creader_size;  /* sizeof() allocated struct Curl_creader */
+};
+
+/* Phase a reader operates at. */
+typedef enum {
+  CURL_CR_NET,  /* data send to the network (connection filters) */
+  CURL_CR_TRANSFER_ENCODE, /* add transfer-encodings */
+  CURL_CR_PROTOCOL, /* before transfer, but after content decoding */
+  CURL_CR_CONTENT_ENCODE, /* add content-encodings */
+  CURL_CR_CLIENT  /* data read from client */
+} Curl_creader_phase;
+
+/* Client reader instance */
+struct Curl_creader {
+  const struct Curl_crtype *crt;  /* type implementation */
+  struct Curl_creader *next;  /* Downstream reader. */
+  Curl_creader_phase phase; /* phase at which it operates */
+};
+
+/**
+ * Default implementations for do_init, do_write, do_close that
+ * do nothing and pass the data through.
+ */
+CURLcode Curl_creader_def_init(struct Curl_easy *data,
+                               struct Curl_creader *reader);
+void Curl_creader_def_close(struct Curl_easy *data,
+                            struct Curl_creader *reader);
+bool Curl_creader_def_needs_rewind(struct Curl_easy *data,
+                                   struct Curl_creader *reader);
+
+/**
+ * Convenience method for calling `reader->do_read()` that
+ * checks for NULL reader.
+ */
+CURLcode Curl_creader_read(struct Curl_easy *data,
+                           struct Curl_creader *reader,
+                           char *buf, size_t blen, size_t *nread, bool *eos);
+
+/**
+ * Create a new creader instance with given type and phase. Is not
+ * inserted into the writer chain by this call.
+ * Invokes `reader->do_init()`.
+ */
+CURLcode Curl_creader_create(struct Curl_creader **preader,
+                             struct Curl_easy *data,
+                             const struct Curl_crtype *cr_handler,
+                             Curl_creader_phase phase);
+
+/**
+ * Free a creader instance.
+ * Invokes `reader->do_close()`.
+ */
+void Curl_creader_free(struct Curl_easy *data, struct Curl_creader *reader);
+
+/**
+ * Adds a reader to the transfer's reader chain.
+ * The readers `phase` determines where in the chain it is inserted.
+ */
+CURLcode Curl_creader_add(struct Curl_easy *data,
+                          struct Curl_creader *reader);
+
+/**
+ * Read at most `blen` bytes at `buf` from the client.
+ * @param date    the transfer to read client bytes for
+ * @param buf     the memory location to read to
+ * @param blen    the amount of memory at `buf`
+ * @param nread   on return the number of bytes read into `buf`
+ * @param eos     TRUE iff bytes are the end of data from client
+ * @return CURLE_OK on successful read (even 0 length) or error
+ */
+CURLcode Curl_client_read(struct Curl_easy *data, char *buf, size_t blen,
+                          size_t *nread, bool *eos) WARN_UNUSED_RESULT;
+
+/**
+ * TRUE iff client reader needs rewing before it can be used for
+ * a retry request.
+ */
+bool Curl_client_read_needs_rewind(struct Curl_easy *data);
+
+/**
+ * Set the client reader to provide 0 bytes, immediate EOS.
+ */
+CURLcode Client_reader_set_null(struct Curl_easy *data);
+
+/**
+ * Set the client reader the reads from fread callback.
+ */
+CURLcode Client_reader_set_fread(struct Curl_easy *data, curl_off_t len);
+
+/**
+ * Set the client reader the reads from the supplied buf (NOT COPIED).
+ */
+CURLcode Client_reader_set_buf(struct Curl_easy *data,
+                               const char *buf, size_t blen);
+
 #endif /* HEADER_CURL_SENDF_H */

lib/smb.c

@@ -811,8 +811,9 @@ static CURLcode smb_send_and_recv(struct Curl_easy *data, void **msg)
   if(!smbc->send_size && smbc->upload_size) {
     size_t nread = smbc->upload_size > (size_t)data->set.upload_buffer_size ?
       (size_t)data->set.upload_buffer_size : smbc->upload_size;
-    data->req.upload_fromhere = data->state.ulbuf;
-    result = Curl_fillreadbuffer(data, nread, &nread);
+    bool eos;
+
+    result = Curl_client_read(data, data->state.ulbuf, nread, &nread, &eos);
     if(result && result != CURLE_AGAIN)
       return result;
     if(!nread)

lib/tftp.c

@@ -708,6 +708,8 @@ static CURLcode tftp_tx(struct tftp_state_data *state, tftp_event_t event)
   struct SingleRequest *k = &data->req;
   size_t cb; /* Bytes currently read */
   char buffer[STRERROR_LEN];
+  char *bufptr;
+  bool eos;
 
   switch(event) {
 
@@ -771,13 +773,14 @@ static CURLcode tftp_tx(struct tftp_state_data *state, tftp_event_t event)
      * data block.
      * */
     state->sbytes = 0;
-    state->data->req.upload_fromhere = (char *)state->spacket.data + 4;
+    bufptr = (char *)state->spacket.data + 4;
     do {
-      result = Curl_fillreadbuffer(data, state->blksize - state->sbytes, &cb);
+      result = Curl_client_read(data, bufptr, state->blksize - state->sbytes,
+                                &cb, &eos);
       if(result)
         return result;
       state->sbytes += (int)cb;
-      state->data->req.upload_fromhere += cb;
+      bufptr += cb;
     } while(state->sbytes < state->blksize && cb);
 
     sbytes = sendto(state->sockfd, (void *) state->spacket.data,

lib/transfer.c

@@ -125,250 +125,6 @@ CURLcode Curl_get_upload_buffer(struct Curl_easy *data)
   return CURLE_OK;
 }
 
-#ifndef CURL_DISABLE_HTTP
-/*
- * This function will be called to loop through the trailers buffer
- * until no more data is available for sending.
- */
-static size_t trailers_read(char *buffer, size_t size, size_t nitems,
-                            void *raw)
-{
-  struct Curl_easy *data = (struct Curl_easy *)raw;
-  struct dynbuf *trailers_buf = &data->state.trailers_buf;
-  size_t bytes_left = Curl_dyn_len(trailers_buf) -
-    data->state.trailers_bytes_sent;
-  size_t to_copy = (size*nitems < bytes_left) ? size*nitems : bytes_left;
-  if(to_copy) {
-    memcpy(buffer,
-           Curl_dyn_ptr(trailers_buf) + data->state.trailers_bytes_sent,
-           to_copy);
-    data->state.trailers_bytes_sent += to_copy;
-  }
-  return to_copy;
-}
-
-static size_t trailers_left(void *raw)
-{
-  struct Curl_easy *data = (struct Curl_easy *)raw;
-  struct dynbuf *trailers_buf = &data->state.trailers_buf;
-  return Curl_dyn_len(trailers_buf) - data->state.trailers_bytes_sent;
-}
-#endif
-
-/*
- * This function will call the read callback to fill our buffer with data
- * to upload.
- */
-CURLcode Curl_fillreadbuffer(struct Curl_easy *data, size_t bytes,
-                             size_t *nreadp)
-{
-  size_t buffersize = bytes;
-  size_t nread;
-  curl_read_callback readfunc = NULL;
-  void *extra_data = NULL;
-  int eof_index = 0;
-
-#ifndef CURL_DISABLE_HTTP
-  if(data->state.trailers_state == TRAILERS_INITIALIZED) {
-    struct curl_slist *trailers = NULL;
-    CURLcode result;
-    int trailers_ret_code;
-
-    /* at this point we already verified that the callback exists
-       so we compile and store the trailers buffer, then proceed */
-    infof(data,
-          "Moving trailers state machine from initialized to sending.");
-    data->state.trailers_state = TRAILERS_SENDING;
-    Curl_dyn_init(&data->state.trailers_buf, DYN_TRAILERS);
-
-    data->state.trailers_bytes_sent = 0;
-    Curl_set_in_callback(data, true);
-    trailers_ret_code = data->set.trailer_callback(&trailers,
-                                                   data->set.trailer_data);
-    Curl_set_in_callback(data, false);
-    if(trailers_ret_code == CURL_TRAILERFUNC_OK) {
-      result = Curl_http_compile_trailers(trailers, &data->state.trailers_buf,
-                                          data);
-    }
-    else {
-      failf(data, "operation aborted by trailing headers callback");
-      *nreadp = 0;
-      result = CURLE_ABORTED_BY_CALLBACK;
-    }
-    if(result) {
-      Curl_dyn_free(&data->state.trailers_buf);
-      curl_slist_free_all(trailers);
-      return result;
-    }
-    infof(data, "Successfully compiled trailers.");
-    curl_slist_free_all(trailers);
-  }
-#endif
-
-#ifndef CURL_DISABLE_HTTP
-  /* if we are transmitting trailing data, we don't need to write
-     a chunk size so we skip this */
-  if(data->req.upload_chunky &&
-     data->state.trailers_state == TRAILERS_NONE) {
-    /* if chunked Transfer-Encoding */
-    buffersize -= (8 + 2 + 2);   /* 32bit hex + CRLF + CRLF */
-    data->req.upload_fromhere += (8 + 2); /* 32bit hex + CRLF */
-  }
-
-  if(data->state.trailers_state == TRAILERS_SENDING) {
-    /* if we're here then that means that we already sent the last empty chunk
-       but we didn't send a final CR LF, so we sent 0 CR LF. We then start
-       pulling trailing data until we have no more at which point we
-       simply return to the previous point in the state machine as if
-       nothing happened.
-       */
-    readfunc = trailers_read;
-    extra_data = (void *)data;
-    eof_index = 1;
-  }
-  else
-#endif
-  {
-    readfunc = data->state.fread_func;
-    extra_data = data->state.in;
-  }
-
-  if(!data->req.fread_eof[eof_index]) {
-    Curl_set_in_callback(data, true);
-    nread = readfunc(data->req.upload_fromhere, 1, buffersize, extra_data);
-    Curl_set_in_callback(data, false);
-    /* make sure the callback is not called again after EOF */
-    data->req.fread_eof[eof_index] = !nread;
-  }
-  else
-    nread = 0;
-
-  if(nread == CURL_READFUNC_ABORT) {
-    failf(data, "operation aborted by callback");
-    *nreadp = 0;
-    return CURLE_ABORTED_BY_CALLBACK;
-  }
-  if(nread == CURL_READFUNC_PAUSE) {
-    struct SingleRequest *k = &data->req;
-
-    if(data->conn->handler->flags & PROTOPT_NONETWORK) {
-      /* protocols that work without network cannot be paused. This is
-         actually only FILE:// just now, and it can't pause since the transfer
-         isn't done using the "normal" procedure. */
-      failf(data, "Read callback asked for PAUSE when not supported");
-      return CURLE_READ_ERROR;
-    }
-
-    /* CURL_READFUNC_PAUSE pauses read callbacks that feed socket writes */
-    k->keepon |= KEEP_SEND_PAUSE; /* mark socket send as paused */
-    if(data->req.upload_chunky) {
-        /* Back out the preallocation done above */
-      data->req.upload_fromhere -= (8 + 2);
-    }
-    *nreadp = 0;
-
-    return CURLE_OK; /* nothing was read */
-  }
-  else if(nread > buffersize) {
-    /* the read function returned a too large value */
-    *nreadp = 0;
-    failf(data, "read function returned funny value");
-    return CURLE_READ_ERROR;
-  }
-
-#ifndef CURL_DISABLE_HTTP
-  if(!data->req.forbidchunk && data->req.upload_chunky) {
-    /* if chunked Transfer-Encoding
-     *    build chunk:
-     *
-     *        <HEX SIZE> CRLF
-     *        <DATA> CRLF
-     */
-    /* On non-ASCII platforms the <DATA> may or may not be
-       translated based on state.prefer_ascii while the protocol
-       portion must always be translated to the network encoding.
-       To further complicate matters, line end conversion might be
-       done later on, so we need to prevent CRLFs from becoming
-       CRCRLFs if that's the case.  To do this we use bare LFs
-       here, knowing they'll become CRLFs later on.
-     */
-
-    bool added_crlf = FALSE;
-    int hexlen = 0;
-    const char *endofline_native;
-    const char *endofline_network;
-
-    if(
-#ifdef CURL_DO_LINEEND_CONV
-       (data->state.prefer_ascii) ||
-#endif
-       (data->set.crlf)) {
-      /* \n will become \r\n later on */
-      endofline_native  = "\n";
-      endofline_network = "\x0a";
-    }
-    else {
-      endofline_native  = "\r\n";
-      endofline_network = "\x0d\x0a";
-    }
-
-    /* if we're not handling trailing data, proceed as usual */
-    if(data->state.trailers_state != TRAILERS_SENDING) {
-      char hexbuffer[11] = "";
-      hexlen = msnprintf(hexbuffer, sizeof(hexbuffer),
-                         "%zx%s", nread, endofline_native);
-
-      /* move buffer pointer */
-      data->req.upload_fromhere -= hexlen;
-      nread += hexlen;
-
-      /* copy the prefix to the buffer, leaving out the NUL */
-      memcpy(data->req.upload_fromhere, hexbuffer, hexlen);
-
-      /* always append ASCII CRLF to the data unless
-         we have a valid trailer callback */
-      if((nread-hexlen) == 0 &&
-          data->set.trailer_callback != NULL &&
-          data->state.trailers_state == TRAILERS_NONE) {
-        data->state.trailers_state = TRAILERS_INITIALIZED;
-      }
-      else {
-        memcpy(data->req.upload_fromhere + nread,
-               endofline_network,
-               strlen(endofline_network));
-        added_crlf = TRUE;
-      }
-    }
-
-    if(data->state.trailers_state == TRAILERS_SENDING &&
-       !trailers_left(data)) {
-      Curl_dyn_free(&data->state.trailers_buf);
-      data->state.trailers_state = TRAILERS_DONE;
-      data->set.trailer_data = NULL;
-      data->set.trailer_callback = NULL;
-      /* mark the transfer as done */
-      data->req.upload_done = TRUE;
-      infof(data, "Signaling end of chunked upload after trailers.");
-    }
-    else
-      if((nread - hexlen) == 0 &&
-         data->state.trailers_state != TRAILERS_INITIALIZED) {
-        /* mark this as done once this chunk is transferred */
-        data->req.upload_done = TRUE;
-        infof(data,
-              "Signaling end of chunked upload via terminating chunk.");
-      }
-
-    if(added_crlf)
-      nread += strlen(endofline_network); /* for the added end of line */
-  }
-#endif
-
-  *nreadp = nread;
-
-  return CURLE_OK;
-}
-
 static int data_pending(struct Curl_easy *data)
 {
   struct connectdata *conn = data->conn;
@@ -616,13 +372,12 @@ static CURLcode readwrite_upload(struct Curl_easy *data,
                                  struct connectdata *conn,
                                  int *didwhat)
 {
-  ssize_t i, si;
   size_t bytes_written;
   CURLcode result;
   ssize_t nread; /* number of bytes read */
-  bool sending_http_headers = FALSE;
   struct SingleRequest *k = &data->req;
 
+  (void)conn;
   *didwhat |= KEEP_SEND;
 
   if(!(k->keepon & KEEP_SEND_PAUSE)) {
@@ -636,13 +391,14 @@ static CURLcode readwrite_upload(struct Curl_easy *data,
   do {
     curl_off_t nbody;
     ssize_t offset = 0;
+    bool eos;
 
     if(0 != k->upload_present &&
        k->upload_present < curl_upload_refill_watermark(data) &&
        !k->upload_chunky &&/*(variable sized chunked header; append not safe)*/
        !k->upload_done &&  /*!(k->upload_done once k->upload_present sent)*/
-       !(k->writebytecount + (curl_off_t)k->upload_present -
-         (curl_off_t)k->pendingheader == data->state.infilesize)) {
+       !(k->writebytecount + (curl_off_t)k->upload_present ==
+         data->state.infilesize)) {
       offset = k->upload_present;
     }
 
@@ -661,10 +417,8 @@ static CURLcode readwrite_upload(struct Curl_easy *data,
         /* HTTP pollution, this should be written nicer to become more
            protocol agnostic. */
         size_t fillcount;
-        struct HTTP *http = k->p.http;
 
-        if((k->exp100 == EXP100_SENDING_REQUEST) &&
-           (http->sending == HTTPSEND_BODY)) {
+        if(k->exp100 == EXP100_SENDING_REQUEST) {
           /* If this call is to send body data, we must take some action:
              We have sent off the full HTTP 1.1 request, and we shall now
              go into the Expect: 100 state and await such a header */
@@ -677,18 +431,10 @@ static CURLcode readwrite_upload(struct Curl_easy *data,
           break;
         }
 
-        if(conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_RTSP)) {
-          if(http->sending == HTTPSEND_REQUEST)
-            /* We're sending the HTTP request headers, not the data.
-               Remember that so we don't change the line endings. */
-            sending_http_headers = TRUE;
-          else
-            sending_http_headers = FALSE;
-        }
-
         k->upload_fromhere += offset;
-        result = Curl_fillreadbuffer(data, data->set.upload_buffer_size-offset,
-                                     &fillcount);
+        result = Curl_client_read(data, k->upload_fromhere,
+                                  data->set.upload_buffer_size-offset,
+                                  &fillcount, &eos);
         k->upload_fromhere -= offset;
         if(result)
           return result;
@@ -712,59 +458,6 @@ static CURLcode readwrite_upload(struct Curl_easy *data,
       /* store number of bytes available for upload */
       k->upload_present = nread;
 
-      /* convert LF to CRLF if so asked */
-      if((!sending_http_headers) && (
-#ifdef CURL_DO_LINEEND_CONV
-         /* always convert if we're FTPing in ASCII mode */
-         (data->state.prefer_ascii) ||
-#endif
-         (data->set.crlf))) {
-        /* Do we need to allocate a scratch buffer? */
-        if(!data->state.scratch) {
-          data->state.scratch = malloc(2 * data->set.upload_buffer_size);
-          if(!data->state.scratch) {
-            failf(data, "Failed to alloc scratch buffer");
-
-            return CURLE_OUT_OF_MEMORY;
-          }
-        }
-
-        /*
-         * ASCII/EBCDIC Note: This is presumably a text (not binary)
-         * transfer so the data should already be in ASCII.
-         * That means the hex values for ASCII CR (0x0d) & LF (0x0a)
-         * must be used instead of the escape sequences \r & \n.
-         */
-        if(offset)
-          memcpy(data->state.scratch, k->upload_fromhere, offset);
-        for(i = offset, si = offset; i < nread; i++, si++) {
-          if(k->upload_fromhere[i] == 0x0a) {
-            data->state.scratch[si++] = 0x0d;
-            data->state.scratch[si] = 0x0a;
-            if(!data->set.crlf) {
-              /* we're here only because FTP is in ASCII mode...
-                 bump infilesize for the LF we just added */
-              if(data->state.infilesize != -1)
-                data->state.infilesize++;
-            }
-          }
-          else
-            data->state.scratch[si] = k->upload_fromhere[i];
-        }
-
-        if(si != nread) {
-          /* only perform the special operation if we really did replace
-             anything */
-          nread = si;
-
-          /* upload from the new (replaced) buffer instead */
-          k->upload_fromhere = data->state.scratch;
-
-          /* set the new amount too */
-          k->upload_present = nread;
-        }
-      }
-
 #ifndef CURL_DISABLE_SMTP
       if(conn->handler->protocol & PROTO_FAMILY_SMTP) {
         result = Curl_smtp_escape_eob(data, nread, offset);
@@ -796,17 +489,7 @@ static CURLcode readwrite_upload(struct Curl_easy *data,
     }
 #endif
 
-    if(k->pendingheader) {
-      /* parts of what was sent was header */
-      size_t n = CURLMIN(k->pendingheader, bytes_written);
-      /* show the data before we change the pointer upload_fromhere */
-      Curl_debug(data, CURLINFO_HEADER_OUT, k->upload_fromhere, n);
-      k->pendingheader -= n;
-      nbody = bytes_written - n; /* size of the written body part */
-    }
-    else
-      nbody = bytes_written;
-
+    nbody = bytes_written;
     if(nbody) {
       /* show the data before we change the pointer upload_fromhere */
       Curl_debug(data, CURLINFO_DATA_OUT,
@@ -1014,7 +697,6 @@ CURLcode Curl_readwrite(struct Curl_easy *data,
      * The transfer has been performed. Just make some general checks before
      * returning.
      */
-
     if(!(data->req.no_body) && (k->size != -1) &&
        (k->bytecount != k->size) &&
 #ifdef CURL_DO_LINEEND_CONV
@@ -1587,8 +1269,7 @@ CURLcode Curl_retry_request(struct Curl_easy *data, char **url)
                                 transferred! */
 
 
-    if((conn->handler->protocol&PROTO_FAMILY_HTTP) &&
-       data->req.writebytecount) {
+    if(Curl_client_read_needs_rewind(data)) {
       data->state.rewindbeforesend = TRUE;
       infof(data, "state.rewindbeforesend = TRUE");
     }
@@ -1611,7 +1292,6 @@ void Curl_xfer_setup(
 {
   struct SingleRequest *k = &data->req;
   struct connectdata *conn = data->conn;
-  struct HTTP *http = data->req.p.http;
   bool want_send = Curl_req_want_send(data);
 
   DEBUGASSERT(conn != NULL);
@@ -1664,8 +1344,7 @@ void Curl_xfer_setup(
          state info where we wait for the 100-return code
       */
       if((data->state.expect100header) &&
-         (conn->handler->protocol&PROTO_FAMILY_HTTP) &&
-         (http->sending == HTTPSEND_BODY)) {
+         (conn->handler->protocol&PROTO_FAMILY_HTTP)) {
         /* wait with write until we either got 100-continue or a timeout */
         k->exp100 = EXP100_AWAITING_CONTINUE;
         k->start100 = Curl_now();

lib/transfer.h

@@ -48,8 +48,6 @@ CURLcode Curl_follow(struct Curl_easy *data, char *newurl,
 CURLcode Curl_readwrite(struct Curl_easy *data, bool *done);
 int Curl_single_getsock(struct Curl_easy *data,
                         struct connectdata *conn, curl_socket_t *socks);
-CURLcode Curl_fillreadbuffer(struct Curl_easy *data, size_t bytes,
-                             size_t *nreadp);
 CURLcode Curl_retry_request(struct Curl_easy *data, char **url);
 bool Curl_meets_timecondition(struct Curl_easy *data, time_t timeofdoc);
 CURLcode Curl_get_upload_buffer(struct Curl_easy *data);

scripts/singleuse.pl

@@ -44,6 +44,8 @@ my $file = $ARGV[0];
 my %wl = (
     'curlx_uztoso' => 'cmdline tool use',
     'Curl_xfer_write_resp' => 'internal api',
+    'Curl_creader_def_init' => 'internal api',
+    'Curl_creader_def_close' => 'internal api',
     );
 
 my %api = (

tests/data/test513

@@ -34,14 +34,6 @@ http://%HOSTIP:%HTTPPORT/%TESTNUMBER
 # Verify data after the test has been "shot"
 <verify>
 <protocol>
-%if !hyper
-POST /%TESTNUMBER HTTP/1.1
-Host: %HOSTIP:%HTTPPORT
-Accept: */*
-Content-Length: 1
-Content-Type: application/x-www-form-urlencoded
-
-%endif
 </protocol>
 # 42 - aborted by callback
 <errorcode>

tests/data/test579

@@ -77,6 +77,8 @@ http://%HOSTIP:%HTTPPORT/%TESTNUMBER %LOGDIR/ip%TESTNUMBER
 <verify>
 <file name="%LOGDIR/ip%TESTNUMBER">
 Progress callback called with UL 0 out of 0
+Progress callback called with UL 5 out of 0
+Progress callback called with UL 0 out of 0
 Progress callback called with UL 8 out of 0
 Progress callback called with UL 16 out of 0
 Progress callback called with UL 26 out of 0

tests/http/test_14_auth.py

@@ -103,9 +103,9 @@ class TestAuth:
     def test_14_05_basic_large_pw(self, env: Env, httpd, nghttpx, repeat, proto):
         if proto == 'h3' and not env.have_h3():
             pytest.skip("h3 not supported")
-        if proto == 'h3' and env.curl_uses_lib('quiche'):
+        if proto == 'h3' and not env.curl_uses_lib('ngtcp2'):
             # See <https://github.com/cloudflare/quiche/issues/1573>
-            pytest.skip("quiche has problems with large requests")
+            pytest.skip("quiche/openssl-quic have problems with large requests")
         # just large enough that nghttp2 will submit
         password = 'x' * (47 * 1024)
         fdata = os.path.join(env.gen_dir, 'data-10m')

tests/libtest/lib547.c

@@ -47,7 +47,7 @@ static size_t readcallback(char  *ptr,
   }
   (*counter)++; /* bump */
 
-  if(size * nmemb > strlen(UPLOADTHIS)) {
+  if(size * nmemb >= strlen(UPLOADTHIS)) {
     fprintf(stderr, "READ!\n");
     strcpy(ptr, UPLOADTHIS);
     return strlen(UPLOADTHIS);

tests/libtest/lib555.c

@@ -54,7 +54,7 @@ static size_t readcallback(char  *ptr,
   }
   (*counter)++; /* bump */
 
-  if(size * nmemb > strlen(uploadthis)) {
+  if(size * nmemb >= strlen(uploadthis)) {
     fprintf(stderr, "READ!\n");
     strcpy(ptr, uploadthis);
     return strlen(uploadthis);