C++ Curl_write函数代码示例

CURLcode Curl_pp_flushsend(struct pingpong *pp)
{
  /* we have a piece of a command still left to send */
  struct connectdata *conn = pp->conn;
  ssize_t written;
  CURLcode result = CURLE_OK;
  curl_socket_t sock = conn->sock[FIRSTSOCKET];

  result = Curl_write(conn, sock, pp->sendthis + pp->sendsize -
                      pp->sendleft, pp->sendleft, &written);
  if(result)
    return result;

  if(written != (ssize_t)pp->sendleft) {
    /* only a fraction was sent */
    pp->sendleft -= written;
  }
  else {
    free(pp->sendthis);
    pp->sendthis=NULL;
    pp->sendleft = pp->sendsize = 0;
    pp->response = Curl_tvnow();
  }
  return CURLE_OK;
}

/*
 * Sends data over the connected socket. Use after successful
 * curl_easy_perform() with CURLOPT_CONNECT_ONLY option.
 */
CURLcode curl_easy_send(CURL *curl, const void *buffer, size_t buflen,
                        size_t *n)
{
  curl_socket_t sfd;
  CURLcode ret;
  ssize_t n1;
  struct connectdata *c = NULL;
  struct SessionHandle *data = (struct SessionHandle *)curl;

  ret = easy_connection(data, &sfd, &c);
  if(ret)
    return ret;

  *n = 0;
  ret = Curl_write(c, sfd, buffer, buflen, &n1);

  if(n1 == -1)
    return CURLE_SEND_ERROR;

  /* detect EAGAIN */
  if((CURLE_OK == ret) && (0 == n1))
    return CURLE_AGAIN;

  *n = (size_t)n1;

  return ret;
}

/*
 * Sends data over the connected socket. Use after successful
 * curl_easy_perform() with CURLOPT_CONNECT_ONLY option.
 */
CURLcode curl_easy_send(struct Curl_easy *data, const void *buffer,
                        size_t buflen, size_t *n)
{
  curl_socket_t sfd;
  CURLcode result;
  ssize_t n1;
  struct connectdata *c = NULL;

  result = easy_connection(data, &sfd, &c);
  if(result)
    return result;

  *n = 0;
  result = Curl_write(c, sfd, buffer, buflen, &n1);

  if(n1 == -1)
    return CURLE_SEND_ERROR;

  /* detect EAGAIN */
  if(!result && !n1)
    return CURLE_AGAIN;

  *n = (size_t)n1;

  return result;
}

/* Escape and send a telnet data block */
static CURLcode send_telnet_data(struct connectdata *conn,
                                 char *buffer, ssize_t nread)
{
  ssize_t escapes, i, j, outlen;
  unsigned char *outbuf = NULL;
  CURLcode result = CURLE_OK;
  ssize_t bytes_written, total_written;

  /* Determine size of new buffer after escaping */
  escapes = 0;
  for(i = 0; i < nread; i++)
    if((unsigned char)buffer[i] == CURL_IAC)
      escapes++;
  outlen = nread + escapes;

  if(outlen == nread)
    outbuf = (unsigned char *)buffer;
  else {
    outbuf = malloc(nread + escapes + 1);
    if(!outbuf)
      return CURLE_OUT_OF_MEMORY;

    j = 0;
    for(i = 0; i < nread; i++) {
      outbuf[j++] = buffer[i];
      if((unsigned char)buffer[i] == CURL_IAC)
        outbuf[j++] = CURL_IAC;
    }
    outbuf[j] = '\0';
  }

  total_written = 0;
  while(!result && total_written < outlen) {
    /* Make sure socket is writable to avoid EWOULDBLOCK condition */
    struct pollfd pfd[1];
    pfd[0].fd = conn->sock[FIRSTSOCKET];
    pfd[0].events = POLLOUT;
    switch(Curl_poll(pfd, 1, -1)) {
      case -1:                    /* error, abort writing */
      case 0:                     /* timeout (will never happen) */
        result = CURLE_SEND_ERROR;
        break;
      default:                    /* write! */
        bytes_written = 0;
        result = Curl_write(conn, conn->sock[FIRSTSOCKET],
                            outbuf + total_written,
                            outlen - total_written,
                            &bytes_written);
        total_written += bytes_written;
        break;
    }
  }

  /* Free malloc copy if escaped */
  if(outbuf != (unsigned char *)buffer)
    free(outbuf);

  return result;
}

/***********************************************************************
 *
 * smtp_done()
 *
 * The DONE function. This does what needs to be done after a single DO has
 * performed.
 *
 * Input argument is already checked for validity.
 */
static CURLcode smtp_done(struct connectdata *conn, CURLcode status,
                          bool premature)
{
  struct SessionHandle *data = conn->data;
  struct FTP *smtp = data->state.proto.smtp;
  CURLcode result = CURLE_OK;
  ssize_t bytes_written;
  (void)premature;

  if(!smtp)
    /* When the easy handle is removed from the multi while libcurl is still
     * trying to resolve the host name, it seems that the smtp struct is not
     * yet initialized, but the removal action calls Curl_done() which calls
     * this function. So we simply return success if no smtp pointer is set.
     */
    return CURLE_OK;

  if(status) {
    conn->bits.close = TRUE; /* marked for closure */
    result = status;      /* use the already set error code */
  }
  else
    /* TODO: make this work even when the socket is EWOULDBLOCK in this
       call! */

    /* write to socket (send away data) */
    result = Curl_write(conn,
                        conn->writesockfd,  /* socket to send to */
                        SMTP_EOB,           /* buffer pointer */
                        SMTP_EOB_LEN,       /* buffer size */
                        &bytes_written);    /* actually sent away */


  if(status == CURLE_OK) {
    struct smtp_conn *smtpc = &conn->proto.smtpc;
    struct pingpong *pp = &smtpc->pp;
    pp->response = Curl_tvnow(); /* timeout relative now */

    state(conn, SMTP_POSTDATA);
    /* run the state-machine

       TODO: when the multi interface is used, this _really_ should be using
       the smtp_multi_statemach function but we have no general support for
       non-blocking DONE operations, not in the multi state machine and with
       Curl_done() invokes on several places in the code!
    */
    result = smtp_easy_statemach(conn);
  }

  /* clear these for next connection */
  smtp->transfer = FTPTRANSFER_BODY;

  return result;
}

/* Curl_sendf() sends formated data to the server */
CURLcode Curl_sendf(curl_socket_t sockfd, struct connectdata *conn,
                    const char *fmt, ...)
{
    struct SessionHandle *data = conn->data;
    ssize_t bytes_written;
    size_t write_len;
    CURLcode res;
    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;

    while (1)
    {
        /* Write the buffer to the socket */
        res = Curl_write(conn, sockfd, sptr, write_len, &bytes_written);

        if(CURLE_OK != res)
            break;

        if(data->set.verbose)
            Curl_debug(data, CURLINFO_DATA_OUT, sptr, 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 res;
}

/*
 * add_buffer_send() sends a buffer and frees all associated memory.
 */
static
CURLcode add_buffer_send(int sockfd, struct connectdata *conn, send_buffer *in,
                         long *bytes_written)
{
  ssize_t amount;
  CURLcode res;
  char *ptr;
  int size;

  if(conn->data->set.verbose) {
    fputs("> ", conn->data->set.err);
    /* this data _may_ contain binary stuff */
    fwrite(in->buffer, in->size_used, 1, conn->data->set.err);
  }

  /* 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 = in->buffer;
  size = in->size_used;
  do {
    res = Curl_write(conn, sockfd, ptr, size, &amount);

    if(CURLE_OK != res)
      break;

    if(amount != size) {
      size -= amount;
      ptr += amount;
    }
    else
      break;

  } while(1);

  if(in->buffer)
    free(in->buffer);
  free(in);

  *bytes_written = amount;

  return res;
}

/*
 * The implementation of nghttp2_send_callback type. Here we write |data| with
 * size |length| to the network and return the number of bytes actually
 * written. See the documentation of nghttp2_send_callback for the details.
 */
static ssize_t send_callback(nghttp2_session *h2,
                             const uint8_t *data, size_t length, int flags,
                             void *userp)
{
  struct connectdata *conn = (struct connectdata *)userp;
  ssize_t written;
  CURLcode rc =
    Curl_write(conn, conn->sock[FIRSTSOCKET], data, length, &written);
  (void)h2;
  (void)flags;

  if(rc) {
    failf(conn->data, "Failed sending HTTP2 data");
    return NGHTTP2_ERR_CALLBACK_FAILURE;
  }
  else if(!written)
    return NGHTTP2_ERR_WOULDBLOCK;

  return written;
}

/* TODO: write large chunks of data instead of one byte at a time */
static CURLcode send_telnet_data(struct connectdata *conn,
                                 char *buffer, ssize_t nread)
{
  unsigned char outbuf[2];
  ssize_t bytes_written, total_written;
  int out_count;
  CURLcode result = CURLE_OK;

  while(!result && nread--) {
    outbuf[0] = *buffer++;
    out_count = 1;
    if(outbuf[0] == CURL_IAC)
      outbuf[out_count++] = CURL_IAC;

    total_written = 0;
    do {
      /* Make sure socket is writable to avoid EWOULDBLOCK condition */
      struct pollfd pfd[1];
      pfd[0].fd = conn->sock[FIRSTSOCKET];
      pfd[0].events = POLLOUT;
      switch (Curl_poll(pfd, 1, -1)) {
        case -1:                    /* error, abort writing */
        case 0:                     /* timeout (will never happen) */
          result = CURLE_SEND_ERROR;
          break;
        default:                    /* write! */
          bytes_written = 0;
          result = Curl_write(conn, conn->sock[FIRSTSOCKET],
                              outbuf+total_written, out_count-total_written,
                              &bytes_written);
          total_written += bytes_written;
          break;
      }
      /* handle partial write */
    } while(!result && total_written < out_count);
  }
  return result;
}

/***********************************************************************
 *
 * smtp_done()
 *
 * The DONE function. This does what needs to be done after a single DO has
 * performed.
 *
 * Input argument is already checked for validity.
 */
static CURLcode smtp_done(struct connectdata *conn, CURLcode status,
                          bool premature)
{
  struct SessionHandle *data = conn->data;
  struct FTP *smtp = data->state.proto.smtp;
  CURLcode result=CURLE_OK;
  ssize_t bytes_written;
  (void)premature;

  if(!smtp)
    /* When the easy handle is removed from the multi while libcurl is still
     * trying to resolve the host name, it seems that the smtp struct is not
     * yet initialized, but the removal action calls Curl_done() which calls
     * this function. So we simply return success if no smtp pointer is set.
     */
    return CURLE_OK;

  if(status) {
    conn->bits.close = TRUE; /* marked for closure */
    result = status;      /* use the already set error code */
  }
  else
    /* TODO: make this work even when the socket is EWOULDBLOCK in this call! */

    /* write to socket (send away data) */
    result = Curl_write(conn,
                        conn->writesockfd,  /* socket to send to */
                        SMTP_EOB,           /* buffer pointer */
                        SMTP_EOB_LEN,       /* buffer size */
                        &bytes_written);    /* actually sent away */

  /* clear these for next connection */
  smtp->transfer = FTPTRANSFER_BODY;

  return result;
}

/***********************************************************************
 *
 * smtp_done()
 *
 * The DONE function. This does what needs to be done after a single DO has
 * performed.
 *
 * Input argument is already checked for validity.
 */
static CURLcode smtp_done(struct connectdata *conn, CURLcode status,
                          bool premature)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct SMTP *smtp = data->req.protop;
  struct pingpong *pp = &conn->proto.smtpc.pp;
  char *eob;
  ssize_t len;
  ssize_t bytes_written;

  (void)premature;

  if(!smtp || !pp->conn)
    return CURLE_OK;

  /* Cleanup our per-request based variables */
  Curl_safefree(smtp->custom);

  if(status) {
    connclose(conn, "SMTP done with bad status"); /* marked for closure */
    result = status;         /* use the already set error code */
  }
  else if(!data->set.connect_only && data->set.mail_rcpt &&
          (data->set.upload || data->set.mimepost.kind)) {
    /* Calculate the EOB taking into account any terminating CRLF from the
       previous line of the email or the CRLF of the DATA command when there
       is "no mail data". RFC-5321, sect. 4.1.1.4.

       Note: As some SSL backends, such as OpenSSL, will cause Curl_write() to
       fail when using a different pointer following a previous write, that
       returned CURLE_AGAIN, we duplicate the EOB now rather than when the
       bytes written doesn't equal len. */
    if(smtp->trailing_crlf || !conn->data->state.infilesize) {
      eob = strdup(SMTP_EOB + 2);
      len = SMTP_EOB_LEN - 2;
    }
    else {
      eob = strdup(SMTP_EOB);
      len = SMTP_EOB_LEN;
    }

    if(!eob)
      return CURLE_OUT_OF_MEMORY;

    /* Send the end of block data */
    result = Curl_write(conn, conn->writesockfd, eob, len, &bytes_written);
    if(result) {
      free(eob);
      return result;
    }

    if(bytes_written != len) {
      /* The whole chunk was not sent so keep it around and adjust the
         pingpong structure accordingly */
      pp->sendthis = eob;
      pp->sendsize = len;
      pp->sendleft = len - bytes_written;
    }
    else {
      /* Successfully sent so adjust the response timeout relative to now */
      pp->response = Curl_now();

      free(eob);
    }

    state(conn, SMTP_POSTDATA);

    /* Run the state-machine

       TODO: when the multi interface is used, this _really_ should be using
       the smtp_multi_statemach function but we have no general support for
       non-blocking DONE operations!
    */
    result = smtp_block_statemach(conn);
  }

  /* Clear the transfer mode for the next request */
  smtp->transfer = FTPTRANSFER_BODY;

  return result;
}

//.........这里部分代码省略.........
        socksreq[6] = (unsigned char)ip[2];
        socksreq[7] = (unsigned char)ip[3];
      }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */

    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
            conn->host.name);
      return CURLE_COULDNT_RESOLVE_HOST;
    }
  }

  /*
   * This is currently not supporting "Identification Protocol (RFC1413)".
   */
  socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
  if (proxy_name)
    strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8);

  /*
   * Make connection
   */
  {
    ssize_t actualread;
    ssize_t written;
    int packetsize = 9 +
      (int)strlen((char*)socksreq + 8); /* size including NUL */

    /* Send request */
    code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
    if ((code != CURLE_OK) || (written != packetsize)) {
      failf(data, "Failed to send SOCKS4 connect request.");
      return CURLE_COULDNT_CONNECT;
    }

    packetsize = 8; /* receive data size */

    /* Receive response */
    result = blockread_all(conn, sock, (char *)socksreq, packetsize,
                           &actualread, timeout);
    if ((result != CURLE_OK) || (actualread != packetsize)) {
      failf(data, "Failed to receive SOCKS4 connect request ack.");
      return CURLE_COULDNT_CONNECT;
    }

    /*
     * Response format
     *
     *     +----+----+----+----+----+----+----+----+
     *     | VN | CD | DSTPORT |      DSTIP        |
     *     +----+----+----+----+----+----+----+----+
     * # of bytes:  1    1      2              4
     *
     * VN is the version of the reply code and should be 0. CD is the result
     * code with one of the following values:
     *
     * 90: request granted
     * 91: request rejected or failed
     * 92: request rejected because SOCKS server cannot connect to
     *     identd on the client
     * 93: request rejected because the client program and identd
     *     report different user-ids

//.........这里部分代码省略.........
  objs[1] = event_handle;

  /* Tell winsock what events we want to listen to */
  if(event_select_func(sockfd, event_handle, FD_READ|FD_CLOSE) == SOCKET_ERROR) {
    close_event_func(event_handle);
    FreeLibrary(wsock2);
    return 0;
  }

  /* Keep on listening and act on events */
  while(keepon) {
    waitret = WaitForMultipleObjects(2, objs, FALSE, INFINITE);
    switch(waitret - WAIT_OBJECT_0) {
    case 0:
    {
      unsigned char outbuf[2];
      int out_count = 0;
      ssize_t bytes_written;
      char *buffer = buf;
              
      if(!ReadFile(stdin_handle, buf, sizeof(data->state.buffer),
                   &readfile_read, NULL)) {
        keepon = FALSE;
        break;
      }
      nread = readfile_read;
        
      while(nread--) {
        outbuf[0] = *buffer++;
        out_count = 1;
        if(outbuf[0] == CURL_IAC)
          outbuf[out_count++] = CURL_IAC;
          
        Curl_write(conn, conn->sock[FIRSTSOCKET], outbuf,
                   out_count, &bytes_written);
      }
    }
    break;
      
    case 1:
      if(enum_netevents_func(sockfd, event_handle, &events)
         != SOCKET_ERROR) {
        if(events.lNetworkEvents & FD_READ) {
          /* This reallu OUGHT to check its return code. */
          (void)Curl_read(conn, sockfd, buf, BUFSIZE - 1, &nread);
            
          telrcv(conn, (unsigned char *)buf, nread);
          
          fflush(stdout);
            
          /* Negotiate if the peer has started negotiating,
             otherwise don't. We don't want to speak telnet with
             non-telnet servers, like POP or SMTP. */
          if(tn->please_negotiate && !tn->already_negotiated) {
            negotiate(conn);
            tn->already_negotiated = 1;
          }
        }
          
        if(events.lNetworkEvents & FD_CLOSE) {
          keepon = FALSE;
        }
      }
      break;
    }
  }

/*
 * This function logs in to a SOCKS5 proxy and sends the specifics to the final
 * destination server.
 */
CURLcode Curl_SOCKS5(const char *proxy_name,
                     const char *proxy_password,
                     struct connectdata *conn)
{
  /*
    According to the RFC1928, section "6.  Replies". This is what a SOCK5
    replies:

        +----+-----+-------+------+----------+----------+
        |VER | REP |  RSV  | ATYP | BND.ADDR | BND.PORT |
        +----+-----+-------+------+----------+----------+
        | 1  |  1  | X'00' |  1   | Variable |    2     |
        +----+-----+-------+------+----------+----------+

    Where:

    o  VER    protocol version: X'05'
    o  REP    Reply field:
    o  X'00' succeeded
  */

  unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
  ssize_t actualread;
  ssize_t written;
  int result;
  CURLcode code;
  curl_socket_t sock = conn->sock[FIRSTSOCKET];
  struct SessionHandle *data = conn->data;
  long timeout;

  /* get timeout */
  if(data->set.timeout && data->set.connecttimeout) {
    if (data->set.timeout < data->set.connecttimeout)
      timeout = data->set.timeout*1000;
    else
      timeout = data->set.connecttimeout*1000;
  }
  else if(data->set.timeout)
    timeout = data->set.timeout*1000;
  else if(data->set.connecttimeout)
    timeout = data->set.connecttimeout*1000;
  else
    timeout = DEFAULT_CONNECT_TIMEOUT;

  Curl_nonblock(sock, TRUE);

  /* wait until socket gets connected */
  result = Curl_select(CURL_SOCKET_BAD, sock, (int)timeout);

  if(-1 == result) {
    failf(conn->data, "SOCKS5: no connection here");
    return CURLE_COULDNT_CONNECT;
  }
  else if(0 == result) {
    failf(conn->data, "SOCKS5: connection timeout");
    return CURLE_OPERATION_TIMEDOUT;
  }

  if(result & CSELECT_ERR) {
    failf(conn->data, "SOCKS5: error occured during connection");
    return CURLE_COULDNT_CONNECT;
  }

  socksreq[0] = 5; /* version */
  socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */
  socksreq[2] = 0; /* no authentication */
  socksreq[3] = 2; /* username/password */

  Curl_nonblock(sock, FALSE);

  code = Curl_write(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
                      &written);
  if ((code != CURLE_OK) || (written != (2 + (int)socksreq[1]))) {
    failf(data, "Unable to send initial SOCKS5 request.");
    return CURLE_COULDNT_CONNECT;
  }

  Curl_nonblock(sock, TRUE);

  result = Curl_select(sock, CURL_SOCKET_BAD, (int)timeout);

  if(-1 == result) {
    failf(conn->data, "SOCKS5 nothing to read");
    return CURLE_COULDNT_CONNECT;
  }
  else if(0 == result) {
    failf(conn->data, "SOCKS5 read timeout");
    return CURLE_OPERATION_TIMEDOUT;
  }

  if(result & CSELECT_ERR) {
    failf(conn->data, "SOCKS5 read error occured");
    return CURLE_RECV_ERROR;
  }

  Curl_nonblock(sock, FALSE);
//.........这里部分代码省略.........

/***********************************************************************
 *
 * Curl_pp_sendfv()
 *
 * Send the formated string as a command to a pingpong server. Note that
 * the string should not have any CRLF appended, as this function will
 * append the necessary things itself.
 *
 * NOTE: we build the command in a fixed-length buffer, which sets length
 * restrictions on the command!
 *
 * made to never block
 */
CURLcode Curl_pp_vsendf(struct pingpong *pp,
                        const char *fmt,
                        va_list args)
{
  ssize_t bytes_written;
/* may still not be big enough for some krb5 tokens */
#define SBUF_SIZE 1024
  char s[SBUF_SIZE];
  size_t write_len;
  char *sptr=s;
  CURLcode res = CURLE_OK;
  struct connectdata *conn = pp->conn;
  struct SessionHandle *data = conn->data;

#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
  enum protection_level data_sec = conn->data_prot;
#endif

  vsnprintf(s, SBUF_SIZE-3, fmt, args);

  strcat(s, "\r\n"); /* append a trailing CRLF */

  bytes_written=0;
  write_len = strlen(s);

  Curl_pp_init(pp);

#ifdef CURL_DOES_CONVERSIONS
  res = Curl_convert_to_network(data, s, write_len);
  /* Curl_convert_to_network calls failf if unsuccessful */
  if(res != CURLE_OK) {
    return res;
  }
#endif /* CURL_DOES_CONVERSIONS */

#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
  conn->data_prot = prot_cmd;
#endif
  res = Curl_write(conn, conn->sock[FIRSTSOCKET], sptr, write_len,
                   &bytes_written);
#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
  conn->data_prot = data_sec;
#endif

  if(CURLE_OK != res)
    return res;

  if(conn->data->set.verbose)
    Curl_debug(conn->data, CURLINFO_HEADER_OUT,
               sptr, (size_t)bytes_written, conn);

  if(bytes_written != (ssize_t)write_len) {
    /* the whole chunk was not sent, store the rest of the data */
    write_len -= bytes_written;
    sptr += bytes_written;
    pp->sendthis = malloc(write_len);
    if(pp->sendthis) {
      memcpy(pp->sendthis, sptr, write_len);
      pp->sendsize = pp->sendleft = write_len;
    }
    else {
      failf(data, "out of memory");
      res = CURLE_OUT_OF_MEMORY;
    }
  }
  else
    pp->response = Curl_tvnow();

  return res;
}