Example #1
0
static int rhizome_server_parse_http_request(rhizome_http_request *r)
{
  /* Switching to writing, so update the call-back */
  r->alarm.poll.events=POLLOUT;
  watch(&r->alarm);
  // Start building up a response.
  r->request_type = 0;
  // Parse the HTTP "GET" line.
  char *path = NULL;
  size_t pathlen = 0;
  if (str_startswith(r->request, "GET ", &path)) {
    char *p;
    // This loop is guaranteed to terminate before the end of the buffer, because we know that the
    // buffer contains at least "\n\n" and maybe "\r\n\r\n" at the end of the header block.
    for (p = path; !isspace(*p); ++p)
      ;
    pathlen = p - path;
    if ( str_startswith(p, " HTTP/1.", &p)
      && (str_startswith(p, "0", &p) || str_startswith(p, "1", &p))
      && (str_startswith(p, "\r\n", &p) || str_startswith(p, "\n", &p))
    )
      path[pathlen] = '\0';
    else
      path = NULL;
  }
  if (path) {
    char *id = NULL;
    INFOF("RHIZOME HTTP SERVER, GET %s", alloca_toprint(1024, path, pathlen));
    if (strcmp(path, "/favicon.ico") == 0) {
      r->request_type = RHIZOME_HTTP_REQUEST_FAVICON;
      rhizome_server_http_response_header(r, 200, "image/vnd.microsoft.icon", favicon_len);
    } else if (strcmp(path, "/rhizome/groups") == 0) {
      /* Return the list of known groups */
      rhizome_server_sql_query_http_response(r, "id", "groups", "from groups", 32, 1);
    } else if (strcmp(path, "/rhizome/files") == 0) {
      /* Return the list of known files */
      rhizome_server_sql_query_http_response(r, "id", "files", "from files", 32, 1);
    } else if (strcmp(path, "/rhizome/bars") == 0) {
      /* Return the list of known BARs */
      rhizome_server_sql_query_http_response(r, "bar", "manifests", "from manifests", 32, 0);
    } else if (str_startswith(path, "/rhizome/file/", &id)) {
      /* Stream the specified payload */
      if (!rhizome_str_is_file_hash(id)) {
	rhizome_server_simple_http_response(r, 400, "<html><h1>Invalid payload ID</h1></html>\r\n");
      } else {
	// TODO: Check for Range: header and return 206 if returning partial content
	str_toupper_inplace(id);
	long long rowid = -1;
	sqlite_exec_int64(&rowid, "select rowid from files where id='%s';", id);
	if (rowid >= 0 && sqlite3_blob_open(rhizome_db, "main", "files", "data", rowid, 0, &r->blob) != SQLITE_OK)
	  rowid = -1;
	if (rowid == -1) {
	  rhizome_server_simple_http_response(r, 404, "<html><h1>Payload not found</h1></html>\r\n");
	} else {
	  r->source_index = 0;
	  r->blob_end = sqlite3_blob_bytes(r->blob);
	  rhizome_server_http_response_header(r, 200, "application/binary", r->blob_end - r->source_index);
	  r->request_type |= RHIZOME_HTTP_REQUEST_BLOB;
	}
      }
    } else if (str_startswith(path, "/rhizome/manifest/", &id)) {
      // TODO: Stream the specified manifest
      rhizome_server_simple_http_response(r, 500, "<html><h1>Not implemented</h1></html>\r\n");
    } else {
      rhizome_server_simple_http_response(r, 404, "<html><h1>Not found</h1></html>\r\n");
    }
  } else {
    if (debug & DEBUG_RHIZOME_TX)
      DEBUGF("Received malformed HTTP request: %s", alloca_toprint(120, (const char *)r->request, r->request_length));
    rhizome_server_simple_http_response(r, 400, "<html><h1>Malformed request</h1></html>\r\n");
  }
  
  /* Try sending data immediately. */
  rhizome_server_http_send_bytes(r);

  return 0;
}
int rhizome_direct_form_received(rhizome_http_request *r)
{
  const char *submitBareFileURI=confValueGet("rhizome.api.addfile.uri", NULL);

  /* Process completed form based on the set of fields seen */
  if (!strcmp(r->path,"/rhizome/import")) {
    switch(r->fields_seen) {
    case RD_MIME_STATE_MANIFESTHEADERS | RD_MIME_STATE_DATAHEADERS: {
	/* Got a bundle to import */
	DEBUGF("Call bundle import for rhizomedata.%d.{data,file}",
	       r->alarm.poll.fd);
	strbuf manifest_path = strbuf_alloca(50);
	strbuf payload_path = strbuf_alloca(50);
	strbuf_sprintf(manifest_path, "rhizomedirect.%d.manifest", r->alarm.poll.fd);
	strbuf_sprintf(payload_path, "rhizomedirect.%d.data", r->alarm.poll.fd);
	int ret = rhizome_bundle_import_files(strbuf_str(manifest_path), strbuf_str(payload_path), 1); // ttl = 1
	
	DEBUGF("Import returned %d",ret);
	
	rhizome_direct_clear_temporary_files(r);
	/* report back to caller.
	  200 = ok, which is probably appropriate for when we already had the bundle.
	  201 = content created, which is probably appropriate for when we successfully
	  import a bundle (or if we already have it).
	  403 = forbidden, which might be appropriate if we refuse to accept it, e.g.,
	  the import fails due to malformed data etc.
	  (should probably also indicate if we have a newer version if possible)
	*/
	switch (ret) {
	case 0:
	  return rhizome_server_simple_http_response(r, 201, "Bundle succesfully imported.");
	case 2:
	  return rhizome_server_simple_http_response(r, 200, "Bundle already imported.");
	}
	return rhizome_server_simple_http_response(r, 500, "Server error: Rhizome import command failed.");
      }
      break;     
    default:
      /* Clean up after ourselves */
      rhizome_direct_clear_temporary_files(r);	     
    }
  } else if (!strcmp(r->path,"/rhizome/enquiry")) {
    int fd=-1;
    char file[1024];
    switch(r->fields_seen) {
    case RD_MIME_STATE_DATAHEADERS:
      /* Read data buffer in, pass to rhizome direct for comparison with local
	 rhizome database, and send back responses. */
      snprintf(file,1024,"rhizomedirect.%d.%s",r->alarm.poll.fd,"data");
      fd=open(file,O_RDONLY);
      if (fd == -1) {
	WHYF_perror("open(%s, O_RDONLY)", alloca_str_toprint(file));
	/* Clean up after ourselves */
	rhizome_direct_clear_temporary_files(r);	     
	return rhizome_server_simple_http_response(r,500,"Couldn't read a file");
      }
      struct stat stat;
      if (fstat(fd, &stat) == -1) {
	WHYF_perror("stat(%d)", fd);
	/* Clean up after ourselves */
	close(fd);
	rhizome_direct_clear_temporary_files(r);	     
	return rhizome_server_simple_http_response(r,500,"Couldn't stat a file");
      }
      unsigned char *addr = mmap(NULL, stat.st_size, PROT_READ, MAP_SHARED, fd, 0);
      if (addr==MAP_FAILED) {
	WHYF_perror("mmap(NULL, %lld, PROT_READ, MAP_SHARED, %d, 0)", (long long) stat.st_size, fd);
	/* Clean up after ourselves */
	close(fd);
	rhizome_direct_clear_temporary_files(r);	     
	return rhizome_server_simple_http_response(r,500,"Couldn't mmap() a file");
      }
      /* Ask for a fill response.  Regardless of the size of the set of BARs passed
	 to us, we will allow up to 64KB of response. */
      rhizome_direct_bundle_cursor 
	*c=rhizome_direct_get_fill_response(addr,stat.st_size,65536);
      munmap(addr,stat.st_size);
      close(fd);

      if (c)
	{
	  /* TODO: Write out_buffer as the body of the response.
	     We should be able to do this using the async framework fairly easily.
	  */
	  
	  int bytes=c->buffer_offset_bytes+c->buffer_used;
	  r->buffer=malloc(bytes+1024);
	  r->buffer_size=bytes+1024;
	  r->buffer_offset=0;
	  assert(r->buffer);

	  /* Write HTTP response header */
	  struct http_response hr;
	  hr.result_code=200;
	  hr.content_type="binary/octet-stream";
	  hr.content_length=bytes;
	  hr.body=NULL;
	  r->request_type=0;
	  rhizome_server_set_response(r,&hr);
	  assert(r->buffer_offset<1024);

	  /* Now append body and send it back. */
	  bcopy(c->buffer,&r->buffer[r->buffer_length],bytes);
	  r->buffer_length+=bytes;
	  r->buffer_offset=0;

	  /* Clean up cursor after sending response */
	  rhizome_direct_bundle_iterator_free(&c);
	  /* Clean up after ourselves */
	  rhizome_direct_clear_temporary_files(r);	     

	  return 0;
	}
      else
	{
	  return rhizome_server_simple_http_response(r,500,"Could not get response to enquiry");
	}

      /* Clean up after ourselves */
      rhizome_direct_clear_temporary_files(r);	     
      break;
    default:
      /* Clean up after ourselves */
      rhizome_direct_clear_temporary_files(r);	     

      return rhizome_server_simple_http_response(r, 404, "/rhizome/enquiry requires 'data' field");
    }
  }  
  /* Allow servald to be configured to accept files without manifests via HTTP
     from localhost, so that rhizome bundles can be created programatically.
     There are probably still some security loop-holes here, which is part of
     why we leave it disabled by default, but it will be sufficient for testing
     possible uses, including integration with OpenDataKit.
  */
  else if (submitBareFileURI&&(!strcmp(r->path,submitBareFileURI))) {
    if (strcmp(inet_ntoa(r->requestor.sin_addr),
	       confValueGet("rhizome.api.addfile.allowedaddress","127.0.0.1")))
      {	
	DEBUGF("rhizome.api.addfile request received from %s, but is only allowed from %s",
	       inet_ntoa(r->requestor.sin_addr),
	       confValueGet("rhizome.api.addfile.allowedaddress", "127.0.0.1"));

	rhizome_direct_clear_temporary_files(r);	     
	return rhizome_server_simple_http_response(r,404,"Not available from here.");
      }

    switch(r->fields_seen) {
    case RD_MIME_STATE_DATAHEADERS:
      /* We have been given a file without a manifest, we should only
	 accept if it we are configured to do so, and the connection is from
	 localhost.  Otherwise people could cause your servald to create
	 arbitrary bundles, which would be bad.
      */
      /* A bundle to import */
      DEBUGF("Call bundle import sans-manifest for rhizomedata.%d.{data,file}",
	     r->alarm.poll.fd);
      
      char filepath[1024];
      snprintf(filepath,1024,"rhizomedirect.%d.data",r->alarm.poll.fd);

      const char *manifestTemplate
	=confValueGet("rhizome.api.addfile.manifesttemplate", NULL);
      
      if (manifestTemplate&&access(manifestTemplate, R_OK) != 0)
	{
	  rhizome_direct_clear_temporary_files(r);	     
	  return rhizome_server_simple_http_response(r,500,"rhizome.api.addfile.manifesttemplate points to a file I could not read.");
	}

      rhizome_manifest *m = rhizome_new_manifest();
      if (!m)
	{
	  rhizome_server_simple_http_response(r,500,"No free manifest slots. Try again later.");
	  rhizome_direct_clear_temporary_files(r);	     
	  return WHY("Manifest struct could not be allocated -- not added to rhizome");
	}

      if (manifestTemplate)
	if (rhizome_read_manifest_file(m, manifestTemplate, 0) == -1) {
	  rhizome_manifest_free(m);
	  rhizome_direct_clear_temporary_files(r);	     
	  return rhizome_server_simple_http_response(r,500,"rhizome.api.addfile.manifesttemplate can't be read as a manifest.");
	}

      /* Fill in a few missing manifest fields, to make it easier to use when adding new files:
	 - the default service is FILE
	 - use the current time for "date"
	 - if service is file, then use the payload file's basename for "name"
      */
      const char *service = rhizome_manifest_get(m, "service", NULL, 0);
      if (service == NULL) {
	rhizome_manifest_set(m, "service", (service = RHIZOME_SERVICE_FILE));
	if (debug & DEBUG_RHIZOME) DEBUGF("missing 'service', set default service=%s", service);
      } else {
	if (debug & DEBUG_RHIZOME) DEBUGF("manifest contains service=%s", service);
      }
      if (rhizome_manifest_get(m, "date", NULL, 0) == NULL) {
	rhizome_manifest_set_ll(m, "date", (long long) gettime_ms());
	if (debug & DEBUG_RHIZOME) DEBUGF("missing 'date', set default date=%s", rhizome_manifest_get(m, "date", NULL, 0));
      }

      const char *name = rhizome_manifest_get(m, "name", NULL, 0);
      if (name == NULL) {
	name=r->data_file_name;
	rhizome_manifest_set(m, "name", r->data_file_name);
	if (debug & DEBUG_RHIZOME) DEBUGF("missing 'name', set name=\"%s\" from HTTP post field filename specification", name);
      } else {
	if (debug & DEBUG_RHIZOME) DEBUGF("manifest contains name=\"%s\"", name);
      }

      const char *senderhex
	= rhizome_manifest_get(m, "sender", NULL, 0);
      if (!senderhex) senderhex=confValueGet("rhizome.api.addfile.author",NULL);
      unsigned char authorSid[SID_SIZE];
      if (senderhex) fromhexstr(authorSid,senderhex,SID_SIZE);
      const char *bskhex
	=confValueGet("rhizome.api.addfile.bundlesecretkey", NULL);   

      /* Bind an ID to the manifest, and also bind the file.  Then finalise the 
	 manifest. But if the manifest already contains an ID, don't override it. */
      if (rhizome_manifest_get(m, "id", NULL, 0) == NULL) {
	if (rhizome_manifest_bind_id(m, senderhex ? authorSid : NULL)) {
	  rhizome_manifest_free(m);
	  m = NULL;
	  rhizome_direct_clear_temporary_files(r);
	  return rhizome_server_simple_http_response(r,500,"Could not bind manifest to an ID");
	}	
      } else if (bskhex) {
	/* Allow user to specify a bundle secret key so that the same bundle can
	   be updated, rather than creating a new bundle each time. */
	unsigned char bsk[RHIZOME_BUNDLE_KEY_BYTES];
	fromhexstr(bsk,bskhex,RHIZOME_BUNDLE_KEY_BYTES);
	memcpy(m->cryptoSignSecret, bsk, RHIZOME_BUNDLE_KEY_BYTES);
	if (rhizome_verify_bundle_privatekey(m) == -1) {
	  rhizome_manifest_free(m);
	  m = NULL;
	  rhizome_direct_clear_temporary_files(r);
	  return rhizome_server_simple_http_response(r,500,"rhizome.api.addfile.bundlesecretkey did not verify.  Using the right key for the right bundle?");
	}
      } else {
	/* Bundle ID specified, but without a BSK or sender SID specified.
	   Therefore we cannot work out the bundle key, and cannot update the
	   bundle. */
	rhizome_manifest_free(m);
	m = NULL;
	rhizome_direct_clear_temporary_files(r);
	return rhizome_server_simple_http_response(r,500,"rhizome.api.addfile.bundlesecretkey not set, and manifest template contains no sender, but template contains a hard-wired bundle ID.  You must specify at least one, or not supply id= in the manifest template.");
	
      }
      
      int encryptP = 0; // TODO Determine here whether payload is to be encrypted.
      if (rhizome_manifest_bind_file(m, filepath, encryptP)) {
	rhizome_manifest_free(m);
	rhizome_direct_clear_temporary_files(r);
	return rhizome_server_simple_http_response(r,500,"Could not bind manifest to file");
      }      
      if (rhizome_manifest_finalise(m)) {
	rhizome_manifest_free(m);
	rhizome_direct_clear_temporary_files(r);
	return rhizome_server_simple_http_response(r,500,
						   "Could not finalise manifest");
      }
      if (rhizome_add_manifest(m,255 /* TTL */)) {
	rhizome_manifest_free(m);
	rhizome_direct_clear_temporary_files(r);
	return rhizome_server_simple_http_response(r,500,
						   "Add manifest operation failed");
      }
            
      DEBUGF("Import sans-manifest appeared to succeed");
      
      /* Respond with the manifest that was added. */
      rhizome_server_simple_http_response(r, 200, (char *)m->manifestdata);

      /* clean up after ourselves */
      rhizome_manifest_free(m);
      rhizome_direct_clear_temporary_files(r);

      return 0;
      break;
    default:
      /* Clean up after ourselves */
      rhizome_direct_clear_temporary_files(r);	     
      
      return rhizome_server_simple_http_response(r, 400, "Rhizome create bundle from file API requires 'data' field");     
    }
  }  

  /* Clean up after ourselves */
  rhizome_direct_clear_temporary_files(r);	     
  /* Report error */
  return rhizome_server_simple_http_response(r, 500, "Something went wrong.  Probably a missing data or manifest part, or invalid combination of URI and data/manifest provision.");

}
int rhizome_direct_parse_http_request(rhizome_http_request *r)
{
  const char *submitBareFileURI=confValueGet("rhizome.api.addfile.uri", NULL);
  DEBUGF("uri=%s", submitBareFileURI ? alloca_str_toprint(submitBareFileURI) : "NULL");
  
  /* Switching to writing, so update the call-back */
  r->alarm.poll.events=POLLOUT;
  watch(&r->alarm);
  // Parse the HTTP request into verb, path, protocol, headers and content.
  char *const request_end = r->request + r->request_length;
  char *verb = r->request;
  char *path = NULL;
  char *proto = NULL;
  size_t pathlen = 0;
  char *headers = NULL;
  int headerlen = 0;
  char *content = NULL;
  int contentlen = 0;
  char *p;
  if ((str_startswith(verb, "GET", &p) || str_startswith(verb, "POST", &p)) && isspace(*p)) {
    *p++ = '\0';
    path = p;
    while (p < request_end && !isspace(*p))
      ++p;
    if (p < request_end) {
      pathlen = p - path;
      *p++ = '\0';
      proto = p;
      if ( str_startswith(p, "HTTP/1.", &p)
	&& (str_startswith(p, "0", &p) || str_startswith(p, "1", &p))
	&& (str_startswith(p, "\r\n", &headers) || str_startswith(p, "\n", &headers))
      ) {
	*p = '\0';
	char *eoh = str_str(headers, "\r\n\r\n", request_end - p);
	if (eoh) {
	  content = eoh + 4;
	  headerlen = content - headers;
	  contentlen = request_end - content;
	}
      }
    }
  }
  if (content == NULL) {
    if (debug & DEBUG_RHIZOME_TX)
      DEBUGF("Received malformed HTTP request %s", alloca_toprint(160, (const char *)r->request, r->request_length));
    return rhizome_server_simple_http_response(r, 400, "<html><h1>Malformed request</h1></html>\r\n");
  }
  INFOF("RHIZOME HTTP SERVER, %s %s %s", verb, alloca_toprint(-1, path, pathlen), proto);
  if (debug & DEBUG_RHIZOME_TX)
    DEBUGF("headers %s", alloca_toprint(-1, headers, headerlen));
  if (strcmp(verb, "GET") == 0 && strcmp(path, "/favicon.ico") == 0) {
    r->request_type = RHIZOME_HTTP_REQUEST_FAVICON;
    rhizome_server_http_response_header(r, 200, "image/vnd.microsoft.icon", favicon_len);
  } else if (strcmp(verb, "POST") == 0
      && (   strcmp(path, "/rhizome/import") == 0 
	  || strcmp(path, "/rhizome/enquiry") == 0
	  || (submitBareFileURI && strcmp(path, submitBareFileURI) == 0)
	 )
  ) {
    const char *cl_str=str_str(headers,"Content-Length: ",headerlen);
    const char *ct_str=str_str(headers,"Content-Type: multipart/form-data; boundary=",headerlen);
    if (!cl_str)
      return rhizome_server_simple_http_response(r,400,"<html><h1>Missing Content-Length header</h1></html>\r\n");
    if (!ct_str)
      return rhizome_server_simple_http_response(r,400,"<html><h1>Missing or unsupported Content-Type header</h1></html>\r\n");
    /* ok, we have content-type and content-length, now make sure they are well formed. */
    long long content_length;
    if (sscanf(cl_str,"Content-Length: %lld",&content_length)!=1)
      return rhizome_server_simple_http_response(r,400,"<html><h1>Malformed Content-Length header</h1></html>\r\n");
    char boundary_string[1024];
    int i;
    ct_str+=strlen("Content-Type: multipart/form-data; boundary=");
    for(i=0;i<1023&&*ct_str&&*ct_str!='\n'&&*ct_str!='\r';i++,ct_str++)
      boundary_string[i]=*ct_str;
    boundary_string[i] = '\0';
    if (i<4||i>128)
      return rhizome_server_simple_http_response(r,400,"<html><h1>Malformed Content-Type header</h1></html>\r\n");

    DEBUGF("content_length=%lld, boundary_string=%s contentlen=%d", (long long) content_length, alloca_str_toprint(boundary_string), contentlen);

    /* Now start receiving and parsing multi-part data.  If we already received some of the
	post-header data, process that first.  Tell the HTTP request that it has moved to multipart
	form data parsing, and what the actual requested action is.
    */

    /* Remember boundary string and source path.
	Put the preceeding -- on the front to make our life easier when
	parsing the rest later. */
    strbuf bs = strbuf_local(r->boundary_string, sizeof r->boundary_string);
    strbuf_puts(bs, "--");
    strbuf_puts(bs, boundary_string);
    if (strbuf_overrun(bs))
      return rhizome_server_simple_http_response(r,500,"<html><h1>Internal server error: Multipart boundary string too long</h1></html>\r\n");
    strbuf ps = strbuf_local(r->path, sizeof r->path);
    strbuf_puts(ps, path);
    if (strbuf_overrun(ps))
      return rhizome_server_simple_http_response(r,500,"<html><h1>Internal server error: Path too long</h1></html>\r\n");
    r->boundary_string_length = strbuf_len(bs);
    r->source_index = 0;
    r->source_count = content_length;
    r->request_type = RHIZOME_HTTP_REQUEST_RECEIVING_MULTIPART;
    r->request_length = 0;
    r->source_flags = 0;

    /* Find the end of the headers and start of any body bytes that we have read
	so far. Copy the bytes to a separate buffer, because r->request and 
	r->request_length get used internally in the parser.
      */
    if (contentlen) {
      char buffer[contentlen];
      bcopy(content, buffer, contentlen);
      rhizome_direct_process_post_multipart_bytes(r, buffer, contentlen);
    }

    /* Handle the rest of the transfer asynchronously. */
    return 0;
  } else {
    rhizome_server_simple_http_response(r, 404, "<html><h1>Not found (OTHER)</h1></html>\r\n");
  }
  
  /* Try sending data immediately. */
  rhizome_server_http_send_bytes(r);

  return 0;
}
int rhizome_direct_process_mime_line(rhizome_http_request *r,char *buffer,int count)
{
  /* Check for boundary line at start of buffer.
     Boundary line = CRLF + "--" + boundary_string + optional whitespace + CRLF
     EXCEPT end of form boundary, which is:
     CRLF + "--" + boundary_string + "--" + CRLF

     NOTE: We attach the "--" to boundary_string when setting things up so that
     we don't have to keep manually checking for it here.

     NOTE: The parser eats the CRLF from the front, and attaches it to the end
     of the previous line.  This means we need to rewind 2 bytes from whatever
     file we were writing to whenever we encounter a boundary line, at least
     if those last two bytes were CRLF. That can be safely assumed if we
     assume that the boundary string has been chosen to be a string never appearing
     anywhere in the contents of the form.  In practice, that is only "almost
     certain" (according to the mathematical meaning of that phrase) if boundary
     strings are randomly selected and are of sufficient length.
   
     NOTE: We are not supporting nested/mixed parts, as that would considerably
     complicate the parser.  If the need arises in future, we will deal with it
     then.  In the meantime, we will have something that meets our immediate
     needs for Rhizome Direct and a variety of use cases.
  */

  /* Regardless of the state of the parser, the presence of boundary lines
     is significant, so lets just check once, and remember the result.
     Similarly check a few other conditions. */
  int boundaryLine=0;
  if (!memcmp(buffer,r->boundary_string,r->boundary_string_length))
    boundaryLine=1;

  int endOfForm=0;
  if (boundaryLine&&
      buffer[r->boundary_string_length]=='-'&&
      buffer[r->boundary_string_length+1]=='-')
    endOfForm=1;
  int blankLine=0;
  if (!strcmp(buffer,"\r\n")) blankLine=1;

  switch(r->source_flags) {
  case RD_MIME_STATE_INITIAL:
    if (boundaryLine) r->source_flags=RD_MIME_STATE_PARTHEADERS;
    break;
  case RD_MIME_STATE_PARTHEADERS:
  case RD_MIME_STATE_MANIFESTHEADERS:
  case RD_MIME_STATE_DATAHEADERS:
    if (blankLine) {
      /* End of headers */
      if (r->source_flags==RD_MIME_STATE_PARTHEADERS)
	{
	  /* Multiple content-disposition lines.  This is very naughty. */
	  rhizome_server_simple_http_response
	    (r, 400, "<html><h1>Malformed multi-part form POST: Missing content-disposition lines in MIME encoded part.</h1></html>\r\n");
	  return -1;
	}
      
      /* Prepare to write to file for field.
	 We may have multiple rhizome direct transactions running at the same
	 time on different TCP connections.  So serialise using file descriptor.
	 We could use the boundary string or some other random thing, but using
	 the file descriptor places a reasonable upper limit on the clutter that
	 is possible, while still preventing collisions -- provided that we don't
	 close the file descriptor until we have completed processing the 
	 request. */
      r->field_file=NULL;
      char filename[1024];
      char *field="unknown";
      switch(r->source_flags) {
      case RD_MIME_STATE_DATAHEADERS: field="data"; break;
      case RD_MIME_STATE_MANIFESTHEADERS: field="manifest"; break;
      }
      snprintf(filename,1024,"rhizomedirect.%d.%s",r->alarm.poll.fd,field);
      filename[1023]=0;
      r->field_file=fopen(filename,"w");
      if (!r->field_file) {
	WHYF_perror("fopen(%s, \"w\")", alloca_str_toprint(filename));
	rhizome_direct_clear_temporary_files(r);
	rhizome_server_simple_http_response
	  (r, 500, "<html><h1>Sorry, couldn't complete your request, reasonable as it was.  Perhaps try again later.</h1></html>\r\n");
	return -1;
      }
      r->source_flags=RD_MIME_STATE_BODY;
    } else {
      char name[1024];
      char field[1024];
      if (sscanf(buffer,
		 "Content-Disposition: form-data; name=\"%[^\"]\";"
		 " filename=\"%[^\"]\"",field,name)==2)
	{
	  if (r->source_flags!=RD_MIME_STATE_PARTHEADERS)
	    {
	      /* Multiple content-disposition lines.  This is very naughty. */
	      rhizome_server_simple_http_response
		(r, 400, "<html><h1>Malformed multi-part form POST: Multiple content-disposition lines in single MIME encoded part.</h1></html>\r\n");
	      return -1;
	    }
	  if (!strcasecmp(field,"manifest")) 
	    r->source_flags=RD_MIME_STATE_MANIFESTHEADERS;
	  if (!strcasecmp(field,"data")) {
	    r->source_flags=RD_MIME_STATE_DATAHEADERS;
	    /* record file name of data field for HTTP manifest-less import */
	    strncpy(r->data_file_name,name,1023);
	    r->data_file_name[1023]=0;
	  }
	  if (r->source_flags!=RD_MIME_STATE_PARTHEADERS)
	    r->fields_seen|=r->source_flags;
	} 
    }
    break;
  case RD_MIME_STATE_BODY:
    if (boundaryLine) {
      r->source_flags=RD_MIME_STATE_PARTHEADERS;

      /* We will have written an extra CRLF to the end of the file,
	 so prune that off. */
      fflush(r->field_file);
      int fd=fileno(r->field_file);
      off_t correct_size=ftell(r->field_file)-2;
      ftruncate(fd,correct_size);
      fclose(r->field_file);
      r->field_file=NULL;
    }
    else {
      int written=fwrite(r->request,count,1,r->field_file);
      if (written<1) 
	DEBUGF("Short write for multi-part form file -- %d bytes may be missing",
	       count);
    }
    break;
  }

  if (endOfForm) {
    /* End of form marker found. 
       Pass it to function that deals with what has been received,
       and will also send response or close the http request if required. */

    /* XXX Rewind last two bytes from file if open, and close file */

    return rhizome_direct_form_received(r);
  }
  return 0;
}