Commit 665b3e48 authored by Patrick Monnerat's avatar Patrick Monnerat
Browse files

cli tool: reimplement stdin buffering in -F option. 

If stdin is not a regular file, its content is memory-buffered to enable
a possible data "rewind".
In all cases, stdin data size is determined before real use to avoid
having an unknown part's size.

--libcurl generated code is left as an unbuffered stdin fread/fseek callback
part with unknown data size.

Buffering is not supported in deprecated curl_formadd() API.
parent f64c0527

docs/cmdline-opts/form.d

+6 −3
Original line number Diff line number Diff line
@@ -25,9 +25,12 @@ the form-field to which portrait.jpg will be the input: 
 curl -F profile=@portrait.jpg https://example.com/upload.cgi



To read content from stdin instead of a file, use - as the filename. This goes

for both @ and < constructs. For this case, as well as for others in which the

full data size cannot be determined before the transfer starts (as named pipes

or similar), data is transferred as chunks by HTTP and rejected by IMAP.

for both @ and < constructs. If stdin is not attached to a regular file, it is

buffered first to determine its size and allow a possible resend. Defining a

part's data from a named non-regular file (such as a named pipe or similar) is

unfortunately not subject to buffering and will be effectively read at

transmission time; since the full size is unknown before the transfer starts,

data is sent as chunks by HTTP and rejected by IMAP.



You can also tell curl what Content-Type to use by using 'type=', in a manner

similar to:

src/tool_formparse.c

+146 −5
Original line number Diff line number Diff line
@@ -31,10 +31,21 @@ 
#include "tool_cfgable.h"

#include "tool_convert.h"

#include "tool_msgs.h"

#include "tool_binmode.h"

#include "tool_formparse.h"



#include "memdebug.h" /* keep this as LAST include */



#define STDIN_BUFSIZE 0x4000   /* Always have 16K to read more stdin data. */



/* Stdin parameters. */

typedef struct {

  char *data;  /* Memory data. */

  curl_off_t origin;  /* File read origin offset. */

  curl_off_t size; /* Data size. */

  curl_off_t curpos; /* Current read position. */

}  standard_input;





/*

 * helper function to get a word from form param
@@ -372,16 +383,146 @@ static int get_param_part(struct OperationConfig *config, char **str, 
  return sep & 0xFF;

}



/* Check if file is "-". If so, use a callback to read OUR stdin (to



/* Mime part callbacks for stdin. */

static size_t stdin_read(char *buffer, size_t size, size_t nitems, void *arg)

{

  standard_input *sip = (standard_input *) arg;

  curl_off_t bytesleft;

  (void) size;  /* Always 1: ignored. */



  if(sip->curpos >= sip->size)

    return 0;  /* At eof. */

  bytesleft = sip->size - sip->curpos;

  if((curl_off_t) nitems > bytesleft)

    nitems = (size_t) bytesleft;

  if(sip->data) {

    /* Return data from memory. */

    memcpy(buffer, sip->data + (size_t) sip->curpos, nitems);

  }

  else {

    /* Read from stdin. */

    nitems = fread(buffer, 1, nitems, stdin);

  }

  sip->curpos += nitems;

  return nitems;

}



static int stdin_seek(void *instream, curl_off_t offset, int whence)

{

  standard_input *sip = (standard_input *) instream;



  switch(whence) {

  case SEEK_CUR:

    offset += sip->curpos;

    break;

  case SEEK_END:

    offset += sip->size;

    break;

  }

  if(offset < 0)

    return CURL_SEEKFUNC_CANTSEEK;

  if(!sip->data) {

    if(fseek(stdin, (long) (offset + sip->origin), SEEK_SET))

      return CURL_SEEKFUNC_CANTSEEK;

  }

  sip->curpos = offset;

  return CURL_SEEKFUNC_OK;

}



static void stdin_free(void *ptr)

{

  standard_input *sip = (standard_input *) ptr;



  Curl_safefree(sip->data);

  free(sip);

}



/* Set a part's data from a file, taking care about the pseudo filename "-" as

 * a shortcut to read stdin: if so, use a callback to read OUR stdin (to

 * workaround Windows DLL file handle caveat).

 * Else use curl_mime_filedata(). */

 * If stdin is a regular file opened in binary mode, save current offset as

 * origin for rewind and do not buffer data. Else read to EOF and keep in

 * memory. In all cases, compute the stdin data size.

 */

static CURLcode file_or_stdin(curl_mimepart *part, const char *file)

{

  standard_input *sip = NULL;

  int fd = -1;

  CURLcode result = CURLE_OK;

  struct_stat sbuf;



  if(strcmp(file, "-"))

    return curl_mime_filedata(part, file);



  return curl_mime_data_cb(part, -1, (curl_read_callback) fread,

                           (curl_seek_callback) fseek, NULL, stdin);

  sip = (standard_input *) malloc(sizeof *sip);

  if(!sip)

    return CURLE_OUT_OF_MEMORY;



  memset((char *) sip, 0, sizeof *sip);

  set_binmode(stdin);



  /* If stdin is a regular file, do not buffer data but read it when needed. */

  fd = fileno(stdin);

  sip->origin = ftell(stdin);

  if(fd >= 0 && sip->origin >= 0 && !fstat(fd, &sbuf) &&

#ifdef __VMS

     sbuf.st_fab_rfm != FAB$C_VAR && sbuf.st_fab_rfm != FAB$C_VFC &&

#endif

     S_ISREG(sbuf.st_mode)) {

    sip->size = sbuf.st_size - sip->origin;

    if(sip->size < 0)

      sip->size = 0;

  }

  else {

    /* Not suitable for direct use, buffer stdin data. */

    sip->origin = 0;

    sip->size = 0;

    sip->curpos = STDIN_BUFSIZE;

    sip->data = malloc(STDIN_BUFSIZE);

    if(!sip->data) {

      stdin_free(sip);

      return CURLE_OUT_OF_MEMORY;

    }

    for(;;) {

      size_t wantbytes = (size_t) (sip->curpos - sip->size);

      size_t havebytes = fread(sip->data + (size_t) sip->size, 1, wantbytes,

                               stdin);

      char *p;



      sip->size += havebytes;

      if(ferror(stdin)) {

        stdin_free(sip);

        return CURLE_READ_ERROR;

      }

      if(!havebytes || feof(stdin))

        break;



      /* Enlarge data buffer. */

      p = realloc(sip->data, (size_t) sip->size + STDIN_BUFSIZE);

      if(!p) {

        stdin_free(sip);

        return CURLE_OUT_OF_MEMORY;

      }

      sip->data = p;

      sip->curpos = sip->size + STDIN_BUFSIZE;

    }

    /* Shrink buffer to spare memory resources. */

    if(sip->size < sip->curpos)

      sip->data = realloc(sip->data, (size_t) sip->size);

  }

  sip->curpos = 0;  /* Rewind. */



  /* Set remote file name. */

  result = curl_mime_filename(part, file);



  /* Set part's data from callback. */

  if(!result)

    result = curl_mime_data_cb(part, sip->size,

                               stdin_read, stdin_seek, stdin_free, sip);

  if(result)

    stdin_free(sip);

  return result;

}
@@ -650,7 +791,7 @@ int formparse(struct OperationConfig *config, 
      if(*contp == '<' && !literal_value) {

        ++contp;

        sep = get_param_part(config, &contp,

                             &data, &type, &filename, &encoder, &headers);

                             &data, &type, NULL, &encoder, &headers);

        if(sep < 0) {

          Curl_safefree(contents);

          return 21;

tests/data/test173

+1 −6
Original line number Diff line number Diff line
@@ -53,11 +53,9 @@ POST /we/want/173 HTTP/1.1 
User-Agent: curl/7.12.1-CVS (i686-pc-linux-gnu) libcurl/7.12.1-CVS OpenSSL/0.9.6b ipv6 zlib/1.1.4 GSS libidn/0.4.6

Host: %HOSTIP:%HTTPPORT

Accept: */*

Transfer-Encoding: chunked

Expect: 100-continue

Content-Length: 360

Content-Type: multipart/form-data; boundary=----------------------------5dbea401cd8c



168

------------------------------5dbea401cd8c

Content-Disposition: form-data; name="field1"
@@ -76,9 +74,6 @@ line7 
line8



------------------------------5dbea401cd8c--



0



</protocol>

</verify>

</testcase>