--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/sendf.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,821 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+
+#ifdef HAVE_LINUX_TCP_H
+#include <linux/tcp.h>
+#endif
+
+#include <curl/curl.h>
+
+#include "urldata.h"
+#include "sendf.h"
+#include "connect.h"
+#include "vtls/vtls.h"
+#include "ssh.h"
+#include "easyif.h"
+#include "multiif.h"
+#include "non-ascii.h"
+#include "strerror.h"
+#include "select.h"
+#include "strdup.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+#ifdef CURL_DO_LINEEND_CONV
+/*
+ * convert_lineends() changes CRLF (\r\n) end-of-line markers to a single LF
+ * (\n), with special processing for CRLF sequences that are split between two
+ * blocks of data.  Remaining, bare CRs are changed to LFs.  The possibly new
+ * size of the data is returned.
+ */
+static size_t convert_lineends(struct Curl_easy *data,
+                               char *startPtr, size_t size)
+{
+  char *inPtr, *outPtr;
+
+  /* sanity check */
+  if((startPtr == NULL) || (size < 1)) {
+    return size;
+  }
+
+  if(data->state.prev_block_had_trailing_cr) {
+    /* The previous block of incoming data
+       had a trailing CR, which was turned into a LF. */
+    if(*startPtr == '\n') {
+      /* This block of incoming data starts with the
+         previous block's LF so get rid of it */
+      memmove(startPtr, startPtr + 1, size-1);
+      size--;
+      /* and it wasn't a bare CR but a CRLF conversion instead */
+      data->state.crlf_conversions++;
+    }
+    data->state.prev_block_had_trailing_cr = FALSE; /* reset the flag */
+  }
+
+  /* find 1st CR, if any */
+  inPtr = outPtr = memchr(startPtr, '\r', size);
+  if(inPtr) {
+    /* at least one CR, now look for CRLF */
+    while(inPtr < (startPtr + size-1)) {
+      /* note that it's size-1, so we'll never look past the last byte */
+      if(memcmp(inPtr, "\r\n", 2) == 0) {
+        /* CRLF found, bump past the CR and copy the NL */
+        inPtr++;
+        *outPtr = *inPtr;
+        /* keep track of how many CRLFs we converted */
+        data->state.crlf_conversions++;
+      }
+      else {
+        if(*inPtr == '\r') {
+          /* lone CR, move LF instead */
+          *outPtr = '\n';
+        }
+        else {
+          /* not a CRLF nor a CR, just copy whatever it is */
+          *outPtr = *inPtr;
+        }
+      }
+      outPtr++;
+      inPtr++;
+    } /* end of while loop */
+
+    if(inPtr < startPtr + size) {
+      /* handle last byte */
+      if(*inPtr == '\r') {
+        /* deal with a CR at the end of the buffer */
+        *outPtr = '\n'; /* copy a NL instead */
+        /* note that a CRLF might be split across two blocks */
+        data->state.prev_block_had_trailing_cr = TRUE;
+      }
+      else {
+        /* copy last byte */
+        *outPtr = *inPtr;
+      }
+      outPtr++;
+    }
+    if(outPtr < startPtr + size)
+      /* tidy up by null terminating the now shorter data */
+      *outPtr = '\0';
+
+    return (outPtr - startPtr);
+  }
+  return size;
+}
+#endif /* CURL_DO_LINEEND_CONV */
+
+#ifdef USE_RECV_BEFORE_SEND_WORKAROUND
+bool Curl_recv_has_postponed_data(struct connectdata *conn, int sockindex)
+{
+  struct postponed_data * const psnd = &(conn->postponed[sockindex]);
+  return psnd->buffer && psnd->allocated_size &&
+         psnd->recv_size > psnd->recv_processed;
+}
+
+static void pre_receive_plain(struct connectdata *conn, int num)
+{
+  const curl_socket_t sockfd = conn->sock[num];
+  struct postponed_data * const psnd = &(conn->postponed[num]);
+  size_t bytestorecv = psnd->allocated_size - psnd->recv_size;
+  /* WinSock will destroy unread received data if send() is
+     failed.
+     To avoid lossage of received data, recv() must be
+     performed before every send() if any incoming data is
+     available. However, skip this, if buffer is already full. */
+  if((conn->handler->protocol&PROTO_FAMILY_HTTP) != 0 &&
+     conn->recv[num] == Curl_recv_plain &&
+     (!psnd->buffer || bytestorecv)) {
+    const int readymask = Curl_socket_check(sockfd, CURL_SOCKET_BAD,
+                                            CURL_SOCKET_BAD, 0);
+    if(readymask != -1 && (readymask & CURL_CSELECT_IN) != 0) {
+      /* Have some incoming data */
+      if(!psnd->buffer) {
+        /* Use buffer double default size for intermediate buffer */
+        psnd->allocated_size = 2 * conn->data->set.buffer_size;
+        psnd->buffer = malloc(psnd->allocated_size);
+        psnd->recv_size = 0;
+        psnd->recv_processed = 0;
+#ifdef DEBUGBUILD
+        psnd->bindsock = sockfd; /* Used only for DEBUGASSERT */
+#endif /* DEBUGBUILD */
+        bytestorecv = psnd->allocated_size;
+      }
+      if(psnd->buffer) {
+        ssize_t recvedbytes;
+        DEBUGASSERT(psnd->bindsock == sockfd);
+        recvedbytes = sread(sockfd, psnd->buffer + psnd->recv_size,
+                            bytestorecv);
+        if(recvedbytes > 0)
+          psnd->recv_size += recvedbytes;
+      }
+      else
+        psnd->allocated_size = 0;
+    }
+  }
+}
+
+static ssize_t get_pre_recved(struct connectdata *conn, int num, char *buf,
+                              size_t len)
+{
+  struct postponed_data * const psnd = &(conn->postponed[num]);
+  size_t copysize;
+  if(!psnd->buffer)
+    return 0;
+
+  DEBUGASSERT(psnd->allocated_size > 0);
+  DEBUGASSERT(psnd->recv_size <= psnd->allocated_size);
+  DEBUGASSERT(psnd->recv_processed <= psnd->recv_size);
+  /* Check and process data that already received and storied in internal
+     intermediate buffer */
+  if(psnd->recv_size > psnd->recv_processed) {
+    DEBUGASSERT(psnd->bindsock == conn->sock[num]);
+    copysize = CURLMIN(len, psnd->recv_size - psnd->recv_processed);
+    memcpy(buf, psnd->buffer + psnd->recv_processed, copysize);
+    psnd->recv_processed += copysize;
+  }
+  else
+    copysize = 0; /* buffer was allocated, but nothing was received */
+
+  /* Free intermediate buffer if it has no unprocessed data */
+  if(psnd->recv_processed == psnd->recv_size) {
+    free(psnd->buffer);
+    psnd->buffer = NULL;
+    psnd->allocated_size = 0;
+    psnd->recv_size = 0;
+    psnd->recv_processed = 0;
+#ifdef DEBUGBUILD
+    psnd->bindsock = CURL_SOCKET_BAD;
+#endif /* DEBUGBUILD */
+  }
+  return (ssize_t)copysize;
+}
+#else  /* ! USE_RECV_BEFORE_SEND_WORKAROUND */
+/* Use "do-nothing" macros instead of functions when workaround not used */
+bool Curl_recv_has_postponed_data(struct connectdata *conn, int sockindex)
+{
+  (void)conn;
+  (void)sockindex;
+  return false;
+}
+#define pre_receive_plain(c,n) do {} WHILE_FALSE
+#define get_pre_recved(c,n,b,l) 0
+#endif /* ! USE_RECV_BEFORE_SEND_WORKAROUND */
+
+/* Curl_infof() is for info message along the way */
+
+void Curl_infof(struct Curl_easy *data, const char *fmt, ...)
+{
+  if(data && data->set.verbose) {
+    va_list ap;
+    size_t len;
+    char print_buffer[2048 + 1];
+    va_start(ap, fmt);
+    len = mvsnprintf(print_buffer, sizeof(print_buffer), fmt, ap);
+    /*
+     * Indicate truncation of the input by replacing the last 3 characters
+     * with "...", and transfer the newline over in case the format had one.
+     */
+    if(len >= sizeof(print_buffer)) {
+      len = strlen(fmt);
+      if(fmt[--len] == '\n')
+        msnprintf(print_buffer + (sizeof(print_buffer) - 5), 5, "...\n");
+      else
+        msnprintf(print_buffer + (sizeof(print_buffer) - 4), 4, "...");
+    }
+    va_end(ap);
+    len = strlen(print_buffer);
+    Curl_debug(data, CURLINFO_TEXT, print_buffer, len);
+  }
+}
+
+/* Curl_failf() is for messages stating why we failed.
+ * The message SHALL NOT include any LF or CR.
+ */
+
+void Curl_failf(struct Curl_easy *data, const char *fmt, ...)
+{
+  if(data->set.verbose || data->set.errorbuffer) {
+    va_list ap;
+    size_t len;
+    char error[CURL_ERROR_SIZE + 2];
+    va_start(ap, fmt);
+    mvsnprintf(error, CURL_ERROR_SIZE, fmt, ap);
+    len = strlen(error);
+
+    if(data->set.errorbuffer && !data->state.errorbuf) {
+      strcpy(data->set.errorbuffer, error);
+      data->state.errorbuf = TRUE; /* wrote error string */
+    }
+    if(data->set.verbose) {
+      error[len] = '\n';
+      error[++len] = '\0';
+      Curl_debug(data, CURLINFO_TEXT, error, len);
+    }
+    va_end(ap);
+  }
+}
+
+/* Curl_sendf() sends formatted data to the server */
+CURLcode Curl_sendf(curl_socket_t sockfd, struct connectdata *conn,
+                    const char *fmt, ...)
+{
+  struct Curl_easy *data = conn->data;
+  ssize_t bytes_written;
+  size_t write_len;
+  CURLcode result = CURLE_OK;
+  char *s;
+  char *sptr;
+  va_list ap;
+  va_start(ap, fmt);
+  s = vaprintf(fmt, ap); /* returns an allocated string */
+  va_end(ap);
+  if(!s)
+    return CURLE_OUT_OF_MEMORY; /* failure */
+
+  bytes_written = 0;
+  write_len = strlen(s);
+  sptr = s;
+
+  for(;;) {
+    /* Write the buffer to the socket */
+    result = Curl_write(conn, sockfd, sptr, write_len, &bytes_written);
+
+    if(result)
+      break;
+
+    if(data->set.verbose)
+      Curl_debug(data, CURLINFO_DATA_OUT, sptr, (size_t)bytes_written);
+
+    if((size_t)bytes_written != write_len) {
+      /* if not all was written at once, we must advance the pointer, decrease
+         the size left and try again! */
+      write_len -= bytes_written;
+      sptr += bytes_written;
+    }
+    else
+      break;
+  }
+
+  free(s); /* free the output string */
+
+  return result;
+}
+
+/*
+ * Curl_write() is an internal write function that sends data to the
+ * server. Works with plain sockets, SCP, SSL or kerberos.
+ *
+ * If the write would block (CURLE_AGAIN), we return CURLE_OK and
+ * (*written == 0). Otherwise we return regular CURLcode value.
+ */
+CURLcode Curl_write(struct connectdata *conn,
+                    curl_socket_t sockfd,
+                    const void *mem,
+                    size_t len,
+                    ssize_t *written)
+{
+  ssize_t bytes_written;
+  CURLcode result = CURLE_OK;
+  int num = (sockfd == conn->sock[SECONDARYSOCKET]);
+
+  bytes_written = conn->send[num](conn, num, mem, len, &result);
+
+  *written = bytes_written;
+  if(bytes_written >= 0)
+    /* we completely ignore the curlcode value when subzero is not returned */
+    return CURLE_OK;
+
+  /* handle CURLE_AGAIN or a send failure */
+  switch(result) {
+  case CURLE_AGAIN:
+    *written = 0;
+    return CURLE_OK;
+
+  case CURLE_OK:
+    /* general send failure */
+    return CURLE_SEND_ERROR;
+
+  default:
+    /* we got a specific curlcode, forward it */
+    return result;
+  }
+}
+
+ssize_t Curl_send_plain(struct connectdata *conn, int num,
+                        const void *mem, size_t len, CURLcode *code)
+{
+  curl_socket_t sockfd = conn->sock[num];
+  ssize_t bytes_written;
+  /* WinSock will destroy unread received data if send() is
+     failed.
+     To avoid lossage of received data, recv() must be
+     performed before every send() if any incoming data is
+     available. */
+  pre_receive_plain(conn, num);
+
+#if defined(MSG_FASTOPEN) && !defined(TCP_FASTOPEN_CONNECT) /* Linux */
+  if(conn->bits.tcp_fastopen) {
+    bytes_written = sendto(sockfd, mem, len, MSG_FASTOPEN,
+                           conn->ip_addr->ai_addr, conn->ip_addr->ai_addrlen);
+    conn->bits.tcp_fastopen = FALSE;
+  }
+  else
+#endif
+    bytes_written = swrite(sockfd, mem, len);
+
+  *code = CURLE_OK;
+  if(-1 == bytes_written) {
+    int err = SOCKERRNO;
+
+    if(
+#ifdef WSAEWOULDBLOCK
+      /* This is how Windows does it */
+      (WSAEWOULDBLOCK == err)
+#else
+      /* errno may be EWOULDBLOCK or on some systems EAGAIN when it returned
+         due to its inability to send off data without blocking. We therefore
+         treat both error codes the same here */
+      (EWOULDBLOCK == err) || (EAGAIN == err) || (EINTR == err) ||
+      (EINPROGRESS == err)
+#endif
+      ) {
+      /* this is just a case of EWOULDBLOCK */
+      bytes_written = 0;
+      *code = CURLE_AGAIN;
+    }
+    else {
+      char buffer[STRERROR_LEN];
+      failf(conn->data, "Send failure: %s",
+            Curl_strerror(err, buffer, sizeof(buffer)));
+      conn->data->state.os_errno = err;
+      *code = CURLE_SEND_ERROR;
+    }
+  }
+  return bytes_written;
+}
+
+/*
+ * Curl_write_plain() is an internal write function that sends data to the
+ * server using plain sockets only. Otherwise meant to have the exact same
+ * proto as Curl_write()
+ */
+CURLcode Curl_write_plain(struct connectdata *conn,
+                          curl_socket_t sockfd,
+                          const void *mem,
+                          size_t len,
+                          ssize_t *written)
+{
+  ssize_t bytes_written;
+  CURLcode result;
+  int num = (sockfd == conn->sock[SECONDARYSOCKET]);
+
+  bytes_written = Curl_send_plain(conn, num, mem, len, &result);
+
+  *written = bytes_written;
+
+  return result;
+}
+
+ssize_t Curl_recv_plain(struct connectdata *conn, int num, char *buf,
+                        size_t len, CURLcode *code)
+{
+  curl_socket_t sockfd = conn->sock[num];
+  ssize_t nread;
+  /* Check and return data that already received and storied in internal
+     intermediate buffer */
+  nread = get_pre_recved(conn, num, buf, len);
+  if(nread > 0) {
+    *code = CURLE_OK;
+    return nread;
+  }
+
+  nread = sread(sockfd, buf, len);
+
+  *code = CURLE_OK;
+  if(-1 == nread) {
+    int err = SOCKERRNO;
+
+    if(
+#ifdef WSAEWOULDBLOCK
+      /* This is how Windows does it */
+      (WSAEWOULDBLOCK == err)
+#else
+      /* errno may be EWOULDBLOCK or on some systems EAGAIN when it returned
+         due to its inability to send off data without blocking. We therefore
+         treat both error codes the same here */
+      (EWOULDBLOCK == err) || (EAGAIN == err) || (EINTR == err)
+#endif
+      ) {
+      /* this is just a case of EWOULDBLOCK */
+      *code = CURLE_AGAIN;
+    }
+    else {
+      char buffer[STRERROR_LEN];
+      failf(conn->data, "Recv failure: %s",
+            Curl_strerror(err, buffer, sizeof(buffer)));
+      conn->data->state.os_errno = err;
+      *code = CURLE_RECV_ERROR;
+    }
+  }
+  return nread;
+}
+
+static CURLcode pausewrite(struct Curl_easy *data,
+                           int type, /* what type of data */
+                           const char *ptr,
+                           size_t len)
+{
+  /* signalled to pause sending on this connection, but since we have data
+     we want to send we need to dup it to save a copy for when the sending
+     is again enabled */
+  struct SingleRequest *k = &data->req;
+  struct UrlState *s = &data->state;
+  char *dupl;
+  unsigned int i;
+  bool newtype = TRUE;
+
+  if(s->tempcount) {
+    for(i = 0; i< s->tempcount; i++) {
+      if(s->tempwrite[i].type == type) {
+        /* data for this type exists */
+        newtype = FALSE;
+        break;
+      }
+    }
+    DEBUGASSERT(i < 3);
+  }
+  else
+    i = 0;
+
+  if(!newtype) {
+    /* append new data to old data */
+
+    /* figure out the new size of the data to save */
+    size_t newlen = len + s->tempwrite[i].len;
+    /* allocate the new memory area */
+    char *newptr = realloc(s->tempwrite[i].buf, newlen);
+    if(!newptr)
+      return CURLE_OUT_OF_MEMORY;
+    /* copy the new data to the end of the new area */
+    memcpy(newptr + s->tempwrite[i].len, ptr, len);
+
+    /* update the pointer and the size */
+    s->tempwrite[i].buf = newptr;
+    s->tempwrite[i].len = newlen;
+  }
+  else {
+    dupl = Curl_memdup(ptr, len);
+    if(!dupl)
+      return CURLE_OUT_OF_MEMORY;
+
+    /* store this information in the state struct for later use */
+    s->tempwrite[i].buf = dupl;
+    s->tempwrite[i].len = len;
+    s->tempwrite[i].type = type;
+
+    if(newtype)
+      s->tempcount++;
+  }
+
+  /* mark the connection as RECV paused */
+  k->keepon |= KEEP_RECV_PAUSE;
+
+  DEBUGF(infof(data, "Paused %zu bytes in buffer for type %02x\n",
+               len, type));
+
+  return CURLE_OK;
+}
+
+
+/* chop_write() writes chunks of data not larger than CURL_MAX_WRITE_SIZE via
+ * client write callback(s) and takes care of pause requests from the
+ * callbacks.
+ */
+static CURLcode chop_write(struct connectdata *conn,
+                           int type,
+                           char *optr,
+                           size_t olen)
+{
+  struct Curl_easy *data = conn->data;
+  curl_write_callback writeheader = NULL;
+  curl_write_callback writebody = NULL;
+  char *ptr = optr;
+  size_t len = olen;
+
+  if(!len)
+    return CURLE_OK;
+
+  /* If reading is paused, append this data to the already held data for this
+     type. */
+  if(data->req.keepon & KEEP_RECV_PAUSE)
+    return pausewrite(data, type, ptr, len);
+
+  /* Determine the callback(s) to use. */
+  if(type & CLIENTWRITE_BODY)
+    writebody = data->set.fwrite_func;
+  if((type & CLIENTWRITE_HEADER) &&
+     (data->set.fwrite_header || data->set.writeheader)) {
+    /*
+     * Write headers to the same callback or to the especially setup
+     * header callback function (added after version 7.7.1).
+     */
+    writeheader =
+      data->set.fwrite_header? data->set.fwrite_header: data->set.fwrite_func;
+  }
+
+  /* Chop data, write chunks. */
+  while(len) {
+    size_t chunklen = len <= CURL_MAX_WRITE_SIZE? len: CURL_MAX_WRITE_SIZE;
+
+    if(writebody) {
+      size_t wrote;
+      Curl_set_in_callback(data, true);
+      wrote = writebody(ptr, 1, chunklen, data->set.out);
+      Curl_set_in_callback(data, false);
+
+      if(CURL_WRITEFUNC_PAUSE == wrote) {
+        if(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, "Write callback asked for PAUSE when not supported!");
+          return CURLE_WRITE_ERROR;
+        }
+        return pausewrite(data, type, ptr, len);
+      }
+      if(wrote != chunklen) {
+        failf(data, "Failed writing body (%zu != %zu)", wrote, chunklen);
+        return CURLE_WRITE_ERROR;
+      }
+    }
+
+    ptr += chunklen;
+    len -= chunklen;
+  }
+
+  if(writeheader) {
+    size_t wrote;
+    ptr = optr;
+    len = olen;
+    Curl_set_in_callback(data, true);
+    wrote = writeheader(ptr, 1, len, data->set.writeheader);
+    Curl_set_in_callback(data, false);
+
+    if(CURL_WRITEFUNC_PAUSE == wrote)
+      /* here we pass in the HEADER bit only since if this was body as well
+         then it was passed already and clearly that didn't trigger the
+         pause, so this is saved for later with the HEADER bit only */
+      return pausewrite(data, CLIENTWRITE_HEADER, ptr, len);
+
+    if(wrote != len) {
+      failf(data, "Failed writing header");
+      return CURLE_WRITE_ERROR;
+    }
+  }
+
+  return CURLE_OK;
+}
+
+
+/* Curl_client_write() sends data to the write callback(s)
+
+   The bit pattern defines to what "streams" to write to. Body and/or header.
+   The defines are in sendf.h of course.
+
+   If CURL_DO_LINEEND_CONV is enabled, data is converted IN PLACE to the
+   local character encoding.  This is a problem and should be changed in
+   the future to leave the original data alone.
+ */
+CURLcode Curl_client_write(struct connectdata *conn,
+                           int type,
+                           char *ptr,
+                           size_t len)
+{
+  struct Curl_easy *data = conn->data;
+
+  if(0 == len)
+    len = strlen(ptr);
+
+  DEBUGASSERT(type <= 3);
+
+  /* FTP data may need conversion. */
+  if((type & CLIENTWRITE_BODY) &&
+    (conn->handler->protocol & PROTO_FAMILY_FTP) &&
+    conn->proto.ftpc.transfertype == 'A') {
+    /* convert from the network encoding */
+    CURLcode result = Curl_convert_from_network(data, ptr, len);
+    /* Curl_convert_from_network calls failf if unsuccessful */
+    if(result)
+      return result;
+
+#ifdef CURL_DO_LINEEND_CONV
+    /* convert end-of-line markers */
+    len = convert_lineends(data, ptr, len);
+#endif /* CURL_DO_LINEEND_CONV */
+    }
+
+  return chop_write(conn, type, ptr, len);
+}
+
+CURLcode Curl_read_plain(curl_socket_t sockfd,
+                         char *buf,
+                         size_t bytesfromsocket,
+                         ssize_t *n)
+{
+  ssize_t nread = sread(sockfd, buf, bytesfromsocket);
+
+  if(-1 == nread) {
+    int err = SOCKERRNO;
+    int return_error;
+#ifdef USE_WINSOCK
+    return_error = WSAEWOULDBLOCK == err;
+#else
+    return_error = EWOULDBLOCK == err || EAGAIN == err || EINTR == err;
+#endif
+    if(return_error)
+      return CURLE_AGAIN;
+    return CURLE_RECV_ERROR;
+  }
+
+  /* we only return number of bytes read when we return OK */
+  *n = nread;
+  return CURLE_OK;
+}
+
+/*
+ * Internal read-from-socket function. This is meant to deal with plain
+ * sockets, SSL sockets and kerberos sockets.
+ *
+ * Returns a regular CURLcode value.
+ */
+CURLcode Curl_read(struct connectdata *conn, /* connection data */
+                   curl_socket_t sockfd,     /* read from this socket */
+                   char *buf,                /* store read data here */
+                   size_t sizerequested,     /* max amount to read */
+                   ssize_t *n)               /* amount bytes read */
+{
+  CURLcode result = CURLE_RECV_ERROR;
+  ssize_t nread = 0;
+  size_t bytesfromsocket = 0;
+  char *buffertofill = NULL;
+  struct Curl_easy *data = conn->data;
+
+  /* Set 'num' to 0 or 1, depending on which socket that has been sent here.
+     If it is the second socket, we set num to 1. Otherwise to 0. This lets
+     us use the correct ssl handle. */
+  int num = (sockfd == conn->sock[SECONDARYSOCKET]);
+
+  *n = 0; /* reset amount to zero */
+
+  bytesfromsocket = CURLMIN(sizerequested, (size_t)data->set.buffer_size);
+  buffertofill = buf;
+
+  nread = conn->recv[num](conn, num, buffertofill, bytesfromsocket, &result);
+  if(nread < 0)
+    return result;
+
+  *n += nread;
+
+  return CURLE_OK;
+}
+
+/* return 0 on success */
+int Curl_debug(struct Curl_easy *data, curl_infotype type,
+               char *ptr, size_t size)
+{
+  static const char s_infotype[CURLINFO_END][3] = {
+    "* ", "< ", "> ", "{ ", "} ", "{ ", "} " };
+  int rc = 0;
+
+#ifdef CURL_DOES_CONVERSIONS
+  char *buf = NULL;
+  size_t conv_size = 0;
+
+  switch(type) {
+  case CURLINFO_HEADER_OUT:
+    buf = Curl_memdup(ptr, size);
+    if(!buf)
+      return 1;
+    conv_size = size;
+
+    /* Special processing is needed for this block if it
+     * contains both headers and data (separated by CRLFCRLF).
+     * We want to convert just the headers, leaving the data as-is.
+     */
+    if(size > 4) {
+      size_t i;
+      for(i = 0; i < size-4; i++) {
+        if(memcmp(&buf[i], "\x0d\x0a\x0d\x0a", 4) == 0) {
+          /* convert everything through this CRLFCRLF but no further */
+          conv_size = i + 4;
+          break;
+        }
+      }
+    }
+
+    Curl_convert_from_network(data, buf, conv_size);
+    /* Curl_convert_from_network calls failf if unsuccessful */
+    /* we might as well continue even if it fails...   */
+    ptr = buf; /* switch pointer to use my buffer instead */
+    break;
+  default:
+    /* leave everything else as-is */
+    break;
+  }
+#endif /* CURL_DOES_CONVERSIONS */
+
+  if(data->set.fdebug) {
+    Curl_set_in_callback(data, true);
+    rc = (*data->set.fdebug)(data, type, ptr, size, data->set.debugdata);
+    Curl_set_in_callback(data, false);
+  }
+  else {
+    switch(type) {
+    case CURLINFO_TEXT:
+    case CURLINFO_HEADER_OUT:
+    case CURLINFO_HEADER_IN:
+      fwrite(s_infotype[type], 2, 1, data->set.err);
+      fwrite(ptr, size, 1, data->set.err);
+#ifdef CURL_DOES_CONVERSIONS
+      if(size != conv_size) {
+        /* we had untranslated data so we need an explicit newline */
+        fwrite("\n", 1, 1, data->set.err);
+      }
+#endif
+      break;
+    default: /* nada */
+      break;
+    }
+  }
+#ifdef CURL_DOES_CONVERSIONS
+  free(buf);
+#endif
+  return rc;
+}