urldata.h

#ifndef HEADER_CURL_URLDATA_H
#define HEADER_CURL_URLDATA_H
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2014, 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 http://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.
 *
 ***************************************************************************/

/* This file is for lib internal stuff */

#include "curl_setup.h"

#define PORT_FTP 21
#define PORT_FTPS 990
#define PORT_TELNET 23
#define PORT_HTTP 80
#define PORT_HTTPS 443
#define PORT_DICT 2628
#define PORT_LDAP 389
#define PORT_LDAPS 636
#define PORT_TFTP 69
#define PORT_SSH 22
#define PORT_IMAP 143
#define PORT_IMAPS 993
#define PORT_POP3 110
#define PORT_POP3S 995
#define PORT_SMTP 25
#define PORT_SMTPS 465 /* sometimes called SSMTP */
#define PORT_RTSP 554
#define PORT_RTMP 1935
#define PORT_RTMPT PORT_HTTP
#define PORT_RTMPS PORT_HTTPS
#define PORT_GOPHER 70

#define DICT_MATCH "/MATCH:"
#define DICT_MATCH2 "/M:"
#define DICT_MATCH3 "/FIND:"
#define DICT_DEFINE "/DEFINE:"
#define DICT_DEFINE2 "/D:"
#define DICT_DEFINE3 "/LOOKUP:"

#define CURL_DEFAULT_USER "anonymous"
#define CURL_DEFAULT_PASSWORD "ftp@example.com"

/* Convenience defines for checking protocols or their SSL based version. Each
   protocol handler should only ever have a single CURLPROTO_ in its protocol
   field. */
#define PROTO_FAMILY_HTTP (CURLPROTO_HTTP|CURLPROTO_HTTPS)
#define PROTO_FAMILY_FTP  (CURLPROTO_FTP|CURLPROTO_FTPS)
#define PROTO_FAMILY_POP3 (CURLPROTO_POP3|CURLPROTO_POP3S)
#define PROTO_FAMILY_SMTP (CURLPROTO_SMTP|CURLPROTO_SMTPS)

#define DEFAULT_CONNCACHE_SIZE 5

/* length of longest IPv6 address string including the trailing null */
#define MAX_IPADR_LEN sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")

/* Default FTP/IMAP etc response timeout in milliseconds.
   Symbian OS panics when given a timeout much greater than 1/2 hour.
*/
#define RESP_TIMEOUT (1800*1000)

#include "cookie.h"
#include "formdata.h"

#ifdef USE_SSLEAY
#ifdef USE_OPENSSL
#include <openssl/rsa.h>
#include <openssl/crypto.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#ifdef HAVE_OPENSSL_ENGINE_H
#include <openssl/engine.h>
#endif
#ifdef HAVE_OPENSSL_PKCS12_H
#include <openssl/pkcs12.h>
#endif
#else /* SSLeay-style includes */
#include <rsa.h>
#include <crypto.h>
#include <x509.h>
#include <pem.h>
#include <ssl.h>
#include <err.h>
#ifdef HAVE_OPENSSL_ENGINE_H
#include <engine.h>
#endif
#ifdef HAVE_OPENSSL_PKCS12_H
#include <pkcs12.h>
#endif
#endif /* USE_OPENSSL */
#ifdef USE_GNUTLS
#error Configuration error; cannot use GnuTLS *and* OpenSSL.
#endif
#endif /* USE_SSLEAY */

#ifdef USE_GNUTLS
#include <gnutls/gnutls.h>
#endif

#ifdef USE_POLARSSL
#include <polarssl/ssl.h>
#include <polarssl/version.h>
#if POLARSSL_VERSION_NUMBER<0x01010000
#include <polarssl/havege.h>
#else
#include <polarssl/entropy.h>
#include <polarssl/ctr_drbg.h>
#endif /* POLARSSL_VERSION_NUMBER<0x01010000 */
#endif /* USE_POLARSSL */

#ifdef USE_CYASSL
#undef OCSP_REQUEST  /* avoid cyassl/openssl/ssl.h clash with wincrypt.h */
#undef OCSP_RESPONSE /* avoid cyassl/openssl/ssl.h clash with wincrypt.h */
#include <cyassl/openssl/ssl.h>
#endif

#ifdef USE_NSS
#include <nspr.h>
#include <pk11pub.h>
#endif

#ifdef USE_QSOSSL
#include <qsossl.h>
#endif

#ifdef USE_GSKIT
#include <gskssl.h>
#endif

#ifdef USE_AXTLS
#include <axTLS/ssl.h>
#undef malloc
#undef calloc
#undef realloc
#endif /* USE_AXTLS */

#ifdef USE_SCHANNEL
#include "curl_sspi.h"
#include <schnlsp.h>
#include <schannel.h>
#endif

#ifdef USE_DARWINSSL
#include <Security/Security.h>
/* For some reason, when building for iOS, the omnibus header above does
 * not include SecureTransport.h as of iOS SDK 5.1. */
#include <Security/SecureTransport.h>
#endif

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#include "timeval.h"

#ifdef HAVE_ZLIB_H
#include <zlib.h>               /* for content-encoding */
#ifdef __SYMBIAN32__
/* zlib pollutes the namespace with this definition */
#undef WIN32
#endif
#endif

#include <curl/curl.h>

#include "http_chunks.h" /* for the structs and enum stuff */
#include "hostip.h"
#include "hash.h"
#include "splay.h"

#include "imap.h"
#include "pop3.h"
#include "smtp.h"
#include "ftp.h"
#include "file.h"
#include "ssh.h"
#include "http.h"
#include "rtsp.h"
#include "wildcard.h"
#include "multihandle.h"

#ifdef HAVE_GSSAPI
# ifdef HAVE_GSSGNU
#  include <gss.h>
# elif defined HAVE_GSSMIT
#  include <gssapi/gssapi.h>
#  include <gssapi/gssapi_generic.h>
# else
#  include <gssapi.h>
# endif
#endif

#ifdef HAVE_LIBSSH2_H
#include <libssh2.h>
#include <libssh2_sftp.h>
#endif /* HAVE_LIBSSH2_H */

/* Download buffer size, keep it fairly big for speed reasons */
#undef BUFSIZE
#define BUFSIZE CURL_MAX_WRITE_SIZE

/* Initial size of the buffer to store headers in, it'll be enlarged in case
   of need. */
#define HEADERSIZE 256

#define CURLEASY_MAGIC_NUMBER 0xc0dedbadU

/* Some convenience macros to get the larger/smaller value out of two given.
   We prefix with CURL to prevent name collisions. */
#define CURLMAX(x,y) ((x)>(y)?(x):(y))
#define CURLMIN(x,y) ((x)<(y)?(x):(y))


#ifdef HAVE_GSSAPI
/* Types needed for krb5-ftp connections */
struct krb5buffer {
  void *data;
  size_t size;
  size_t index;
  int eof_flag;
};

enum protection_level {
  PROT_NONE, /* first in list */
  PROT_CLEAR,
  PROT_SAFE,
  PROT_CONFIDENTIAL,
  PROT_PRIVATE,
  PROT_CMD,
  PROT_LAST /* last in list */
};
#endif

#ifdef USE_SCHANNEL
/* Structs to store Schannel handles */
struct curl_schannel_cred {
  CredHandle cred_handle;
  TimeStamp time_stamp;
  int refcount;
  bool cached;
};

struct curl_schannel_ctxt {
  CtxtHandle ctxt_handle;
  TimeStamp time_stamp;
};
#endif

/* enum for the nonblocking SSL connection state machine */
typedef enum {
  ssl_connect_1,
  ssl_connect_2,
  ssl_connect_2_reading,
  ssl_connect_2_writing,
  ssl_connect_3,
  ssl_connect_done
} ssl_connect_state;

typedef enum {
  ssl_connection_none,
  ssl_connection_negotiating,
  ssl_connection_complete
} ssl_connection_state;

/* struct for data related to each SSL connection */
struct ssl_connect_data {
  /* Use ssl encrypted communications TRUE/FALSE, not necessarily using it atm
     but at least asked to or meaning to use it. See 'state' for the exact
     current state of the connection. */
  bool use;
  ssl_connection_state state;
#ifdef USE_SSLEAY
  /* these ones requires specific SSL-types */
  SSL_CTX* ctx;
  SSL*     handle;
  X509*    server_cert;
  ssl_connect_state connecting_state;
#endif /* USE_SSLEAY */
#ifdef USE_GNUTLS
  gnutls_session_t session;
  gnutls_certificate_credentials_t cred;
#ifdef USE_TLS_SRP
  gnutls_srp_client_credentials_t srp_client_cred;
#endif
  ssl_connect_state connecting_state;
#endif /* USE_GNUTLS */
#ifdef USE_POLARSSL
  ctr_drbg_context ctr_drbg;
  entropy_context entropy;
  ssl_context ssl;
  ssl_session ssn;
  int server_fd;
  x509_crt cacert;
  x509_crt clicert;
  x509_crl crl;
  rsa_context rsa;
  ssl_connect_state connecting_state;
#endif /* USE_POLARSSL */
#ifdef USE_CYASSL
  SSL_CTX* ctx;
  SSL*     handle;
  ssl_connect_state connecting_state;
#endif /* USE_CYASSL */
#ifdef USE_NSS
  PRFileDesc *handle;
  char *client_nickname;
  struct SessionHandle *data;
  struct curl_llist *obj_list;
  PK11GenericObject *obj_clicert;
  ssl_connect_state connecting_state;
#endif /* USE_NSS */
#ifdef USE_QSOSSL
  SSLHandle *handle;
#endif /* USE_QSOSSL */
#ifdef USE_GSKIT
  gsk_handle handle;
  int iocport;
  ssl_connect_state connecting_state;
#endif
#ifdef USE_AXTLS
  SSL_CTX* ssl_ctx;
  SSL*     ssl;
  ssl_connect_state connecting_state;
#endif /* USE_AXTLS */
#ifdef USE_SCHANNEL
  struct curl_schannel_cred *cred;
  struct curl_schannel_ctxt *ctxt;
  SecPkgContext_StreamSizes stream_sizes;
  ssl_connect_state connecting_state;
  size_t encdata_length, decdata_length;
  size_t encdata_offset, decdata_offset;
  unsigned char *encdata_buffer, *decdata_buffer;
  unsigned long req_flags, ret_flags;
#endif /* USE_SCHANNEL */
#ifdef USE_DARWINSSL
  SSLContextRef ssl_ctx;
  curl_socket_t ssl_sockfd;
  ssl_connect_state connecting_state;
  bool ssl_direction; /* true if writing, false if reading */
  size_t ssl_write_buffered_length;
#endif /* USE_DARWINSSL */
};

struct ssl_config_data {
  long version;          /* what version the client wants to use */
  long certverifyresult; /* result from the certificate verification */

  bool verifypeer;       /* set TRUE if this is desired */
  bool verifyhost;       /* set TRUE if CN/SAN must match hostname */
  char *CApath;          /* certificate dir (doesn't work on windows) */
  char *CAfile;          /* certificate to verify peer against */
  const char *CRLfile;   /* CRL to check certificate revocation */
  const char *issuercert;/* optional issuer certificate filename */
  char *random_file;     /* path to file containing "random" data */
  char *egdsocket;       /* path to file containing the EGD daemon socket */
  char *cipher_list;     /* list of ciphers to use */
  size_t max_ssl_sessions; /* SSL session id cache size */
  curl_ssl_ctx_callback fsslctx; /* function to initialize ssl ctx */
  void *fsslctxp;        /* parameter for call back */
  bool sessionid;        /* cache session IDs or not */
  bool certinfo;         /* gather lots of certificate info */

#ifdef USE_TLS_SRP
  char *username; /* TLS username (for, e.g., SRP) */
  char *password; /* TLS password (for, e.g., SRP) */
  enum CURL_TLSAUTH authtype; /* TLS authentication type (default SRP) */
#endif
};

/* information stored about one single SSL session */
struct curl_ssl_session {
  char *name;       /* host name for which this ID was used */
  void *sessionid;  /* as returned from the SSL layer */
  size_t idsize;    /* if known, otherwise 0 */
  long age;         /* just a number, the higher the more recent */
  int remote_port;  /* remote port to connect to */
  struct ssl_config_data ssl_config; /* setup for this session */
};

/* Struct used for Digest challenge-response authentication */
struct digestdata {
  char *nonce;
  char *cnonce;
  char *realm;
  int algo;
  bool stale; /* set true for re-negotiation */
  char *opaque;
  char *qop;
  char *algorithm;
  int nc; /* nounce count */
};

typedef enum {
  NTLMSTATE_NONE,
  NTLMSTATE_TYPE1,
  NTLMSTATE_TYPE2,
  NTLMSTATE_TYPE3,
  NTLMSTATE_LAST
} curlntlm;

#ifdef USE_WINDOWS_SSPI
#include "curl_sspi.h"
#endif

#if defined(CURL_DOES_CONVERSIONS) && defined(HAVE_ICONV)
#include <iconv.h>
#endif

/* Struct used for NTLM challenge-response authentication */
struct ntlmdata {
  curlntlm state;
#ifdef USE_WINDOWS_SSPI
  CredHandle handle;
  CtxtHandle c_handle;
  SEC_WINNT_AUTH_IDENTITY identity;
  SEC_WINNT_AUTH_IDENTITY *p_identity;
  int has_handles;
  void *type_2;
  unsigned long n_type_2;
#else
  unsigned int flags;
  unsigned char nonce[8];
  void* target_info; /* TargetInfo received in the ntlm type-2 message */
  unsigned int target_info_len;
#endif
};

#ifdef USE_HTTP_NEGOTIATE
struct negotiatedata {
  /* when doing Negotiate we first need to receive an auth token and then we
     need to send our header */
  enum { GSS_AUTHNONE, GSS_AUTHRECV, GSS_AUTHSENT } state;
  bool gss; /* Whether we're processing GSS-Negotiate or Negotiate */
  const char* protocol; /* "GSS-Negotiate" or "Negotiate" */
#ifdef HAVE_GSSAPI
  OM_uint32 status;
  gss_ctx_id_t context;
  gss_name_t server_name;
  gss_buffer_desc output_token;
#else
#ifdef USE_WINDOWS_SSPI
  DWORD status;
  CtxtHandle *context;
  CredHandle *credentials;
  char server_name[1024];
  size_t max_token_length;
  BYTE *output_token;
  size_t output_token_length;
#endif
#endif
};
#endif


/*
 * Boolean values that concerns this connection.
 */
struct ConnectBits {
  /* always modify bits.close with the connclose() and connkeep() macros! */
  bool close; /* if set, we close the connection after this request */
  bool reuse; /* if set, this is a re-used connection */
  bool proxy; /* if set, this transfer is done through a proxy - any type */
  bool httpproxy;    /* if set, this transfer is done through a http proxy */
  bool user_passwd;    /* do we use user+password for this connection? */
  bool proxy_user_passwd; /* user+password for the proxy? */
  bool ipv6_ip; /* we communicate with a remote site specified with pure IPv6
                   IP address */
  bool ipv6;    /* we communicate with a site using an IPv6 address */

  bool do_more; /* this is set TRUE if the ->curl_do_more() function is
                   supposed to be called, after ->curl_do() */
  bool tcpconnect[2]; /* the TCP layer (or similar) is connected, this is set
                         the first time on the first connect function call */
  bool protoconnstart;/* the protocol layer has STARTED its operation after
                         the TCP layer connect */

  bool retry;         /* this connection is about to get closed and then
                         re-attempted at another connection. */
  bool tunnel_proxy;  /* if CONNECT is used to "tunnel" through the proxy.
                         This is implicit when SSL-protocols are used through
                         proxies, but can also be enabled explicitly by
                         apps */
  bool authneg;       /* TRUE when the auth phase has started, which means
                         that we are creating a request with an auth header,
                         but it is not the final request in the auth
                         negotiation. */
  bool rewindaftersend;/* TRUE when the sending couldn't be stopped even
                          though it will be discarded. When the whole send
                          operation is done, we must call the data rewind
                          callback. */
  bool ftp_use_epsv;  /* As set with CURLOPT_FTP_USE_EPSV, but if we find out
                         EPSV doesn't work we disable it for the forthcoming
                         requests */

  bool ftp_use_eprt;  /* As set with CURLOPT_FTP_USE_EPRT, but if we find out
                         EPRT doesn't work we disable it for the forthcoming
                         requests */
  bool netrc;         /* name+password provided by netrc */
  bool userpwd_in_url; /* name+password found in url */

  bool done;          /* set to FALSE when Curl_do() is called and set to TRUE
                         when Curl_done() is called, to prevent Curl_done() to
                         get invoked twice when the multi interface is
                         used. */
  bool stream_was_rewound; /* Indicates that the stream was rewound after a
                              request read past the end of its response byte
                              boundary */
  bool proxy_connect_closed; /* set true if a proxy disconnected the
                                connection in a CONNECT request with auth, so
                                that libcurl should reconnect and continue. */
  bool bound; /* set true if bind() has already been done on this socket/
                 connection */
  bool type_set;  /* type= was used in the URL */
};

struct hostname {
  char *rawalloc; /* allocated "raw" version of the name */
  char *encalloc; /* allocated IDN-encoded version of the name */
  char *name;     /* name to use internally, might be encoded, might be raw */
  const char *dispname; /* name to display, as 'name' might be encoded */
};

/*
 * Flags on the keepon member of the Curl_transfer_keeper
 */

#define KEEP_NONE  0
#define KEEP_RECV  (1<<0)     /* there is or may be data to read */
#define KEEP_SEND (1<<1)     /* there is or may be data to write */
#define KEEP_RECV_HOLD (1<<2) /* when set, no reading should be done but there
                                 might still be data to read */
#define KEEP_SEND_HOLD (1<<3) /* when set, no writing should be done but there
                                  might still be data to write */
#define KEEP_RECV_PAUSE (1<<4) /* reading is paused */
#define KEEP_SEND_PAUSE (1<<5) /* writing is paused */

#define KEEP_RECVBITS (KEEP_RECV | KEEP_RECV_HOLD | KEEP_RECV_PAUSE)
#define KEEP_SENDBITS (KEEP_SEND | KEEP_SEND_HOLD | KEEP_SEND_PAUSE)


#ifdef HAVE_LIBZ
typedef enum {
  ZLIB_UNINIT,          /* uninitialized */
  ZLIB_INIT,            /* initialized */
  ZLIB_GZIP_HEADER,     /* reading gzip header */
  ZLIB_GZIP_INFLATING,  /* inflating gzip stream */
  ZLIB_INIT_GZIP        /* initialized in transparent gzip mode */
} zlibInitState;
#endif

#ifdef CURLRES_ASYNCH
struct Curl_async {
  char *hostname;
  int port;
  struct Curl_dns_entry *dns;
  bool done;  /* set TRUE when the lookup is complete */
  int status; /* if done is TRUE, this is the status from the callback */
  void *os_specific;  /* 'struct thread_data' for Windows */
};
#endif

#define FIRSTSOCKET     0
#define SECONDARYSOCKET 1

/* These function pointer types are here only to allow easier typecasting
   within the source when we need to cast between data pointers (such as NULL)
   and function pointers. */
typedef CURLcode (*Curl_do_more_func)(struct connectdata *, int *);
typedef CURLcode (*Curl_done_func)(struct connectdata *, CURLcode, bool);

enum expect100 {
  EXP100_SEND_DATA,           /* enough waiting, just send the body now */
  EXP100_AWAITING_CONTINUE,   /* waiting for the 100 Continue header */
  EXP100_SENDING_REQUEST,     /* still sending the request but will wait for
                                 the 100 header once done with the request */
  EXP100_FAILED               /* used on 417 Expectation Failed */
};

enum upgrade101 {
  UPGR101_INIT,               /* default state */
  UPGR101_REQUESTED,          /* upgrade requested */
  UPGR101_RECEIVED,           /* response received */
  UPGR101_WORKING             /* talking upgraded protocol */
};

enum negotiatenpn {
  NPN_INIT,                   /* default state */
  NPN_HTTP1_1,                /* HTTP/1.1 negotiated */
  NPN_HTTP2                   /* HTTP2 (draft-xx) negotiated */
};

/*
 * Request specific data in the easy handle (SessionHandle).  Previously,
 * these members were on the connectdata struct but since a conn struct may
 * now be shared between different SessionHandles, we store connection-specific
 * data here. This struct only keeps stuff that's interesting for *this*
 * request, as it will be cleared between multiple ones
 */
struct SingleRequest {
  curl_off_t size;        /* -1 if unknown at this point */
  curl_off_t *bytecountp; /* return number of bytes read or NULL */

  curl_off_t maxdownload; /* in bytes, the maximum amount of data to fetch,
                             -1 means unlimited */
  curl_off_t *writebytecountp; /* return number of bytes written or NULL */

  curl_off_t bytecount;         /* total number of bytes read */
  curl_off_t writebytecount;    /* number of bytes written */

  long headerbytecount;         /* only count received headers */
  long deductheadercount; /* this amount of bytes doesn't count when we check
                             if anything has been transferred at the end of a
                             connection. We use this counter to make only a
                             100 reply (without a following second response
                             code) result in a CURLE_GOT_NOTHING error code */

  struct timeval start;         /* transfer started at this time */
  struct timeval now;           /* current time */
  bool header;                  /* incoming data has HTTP header */
  enum {
    HEADER_NORMAL,              /* no bad header at all */
    HEADER_PARTHEADER,          /* part of the chunk is a bad header, the rest
                                   is normal data */
    HEADER_ALLBAD               /* all was believed to be header */
  } badheader;                  /* the header was deemed bad and will be
                                   written as body */
  int headerline;               /* counts header lines to better track the
                                   first one */
  char *hbufp;                  /* points at *end* of header line */
  size_t hbuflen;
  char *str;                    /* within buf */
  char *str_start;              /* within buf */
  char *end_ptr;                /* within buf */
  char *p;                      /* within headerbuff */
  bool content_range;           /* set TRUE if Content-Range: was found */
  curl_off_t offset;            /* possible resume offset read from the
                                   Content-Range: header */
  int httpcode;                 /* error code from the 'HTTP/1.? XXX' or
                                   'RTSP/1.? XXX' line */
  struct timeval start100;      /* time stamp to wait for the 100 code from */
  enum expect100 exp100;        /* expect 100 continue state */
  enum upgrade101 upgr101;      /* 101 upgrade state */

  int auto_decoding;            /* What content encoding. sec 3.5, RFC2616. */

#define IDENTITY 0              /* No encoding */
#define DEFLATE 1               /* zlib deflate [RFC 1950 & 1951] */
#define GZIP 2                  /* gzip algorithm [RFC 1952] */
#define COMPRESS 3              /* Not handled, added for completeness */

#ifdef HAVE_LIBZ
  zlibInitState zlib_init;      /* possible zlib init state;
                                   undefined if Content-Encoding header. */
  z_stream z;                   /* State structure for zlib. */
#endif

  time_t timeofdoc;
  long bodywrites;

  char *buf;
  char *uploadbuf;
  curl_socket_t maxfd;

  int keepon;

  bool upload_done; /* set to TRUE when doing chunked transfer-encoding upload
                       and we're uploading the last chunk */

  bool ignorebody;  /* we read a response-body but we ignore it! */
  bool ignorecl;    /* This HTTP response has no body so we ignore the Content-
                       Length: header */

  char *location;   /* This points to an allocated version of the Location:
                       header data */
  char *newurl;     /* Set to the new URL to use when a redirect or a retry is
                       wanted */

  /* 'upload_present' is used to keep a byte counter of how much data there is
     still left in the buffer, aimed for upload. */
  ssize_t upload_present;

   /* 'upload_fromhere' is used as a read-pointer when we uploaded parts of a
      buffer, so the next read should read from where this pointer points to,
      and the 'upload_present' contains the number of bytes available at this
      position */
  char *upload_fromhere;

  bool chunk; /* if set, this is a chunked transfer-encoding */
  bool upload_chunky; /* set TRUE if we are doing chunked transfer-encoding
                         on upload */
  bool getheader;     /* TRUE if header parsing is wanted */

  bool forbidchunk;   /* used only to explicitly forbid chunk-upload for
                         specific upload buffers. See readmoredata() in
                         http.c for details. */

  void *protop;       /* Allocated protocol-specific data. Each protocol
                         handler makes sure this points to data it needs. */
};

/*
 * Specific protocol handler.
 */

struct Curl_handler {
  const char * scheme;        /* URL scheme name. */

  /* Complement to setup_connection_internals(). */
  CURLcode (*setup_connection)(struct connectdata *);

  /* These two functions MUST be set to be protocol dependent */
  CURLcode (*do_it)(struct connectdata *, bool *done);
  Curl_done_func done;

  /* If the curl_do() function is better made in two halves, this
   * curl_do_more() function will be called afterwards, if set. For example
   * for doing the FTP stuff after the PASV/PORT command.
   */
  Curl_do_more_func do_more;

  /* This function *MAY* be set to a protocol-dependent function that is run
   * after the connect() and everything is done, as a step in the connection.
   * The 'done' pointer points to a bool that should be set to TRUE if the
   * function completes before return. If it doesn't complete, the caller
   * should call the curl_connecting() function until it is.
   */
  CURLcode (*connect_it)(struct connectdata *, bool *done);

  /* See above. Currently only used for FTP. */
  CURLcode (*connecting)(struct connectdata *, bool *done);
  CURLcode (*doing)(struct connectdata *, bool *done);

  /* Called from the multi interface during the PROTOCONNECT phase, and it
     should then return a proper fd set */
  int (*proto_getsock)(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks);

  /* Called from the multi interface during the DOING phase, and it should
     then return a proper fd set */
  int (*doing_getsock)(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks);

  /* Called from the multi interface during the DO_MORE phase, and it should
     then return a proper fd set */
  int (*domore_getsock)(struct connectdata *conn,
                        curl_socket_t *socks,
                        int numsocks);

  /* Called from the multi interface during the DO_DONE, PERFORM and
     WAITPERFORM phases, and it should then return a proper fd set. Not setting
     this will make libcurl use the generic default one. */
  int (*perform_getsock)(const struct connectdata *conn,
                         curl_socket_t *socks,
                         int numsocks);

  /* This function *MAY* be set to a protocol-dependent function that is run
   * by the curl_disconnect(), as a step in the disconnection.  If the handler
   * is called because the connection has been considered dead, dead_connection
   * is set to TRUE.
   */
  CURLcode (*disconnect)(struct connectdata *, bool dead_connection);

  /* If used, this function gets called from transfer.c:readwrite_data() to
     allow the protocol to do extra reads/writes */
  CURLcode (*readwrite)(struct SessionHandle *data, struct connectdata *conn,
                        ssize_t *nread, bool *readmore);

  long defport;           /* Default port. */
  unsigned int protocol;  /* See CURLPROTO_* - this needs to be the single
                             specific protocol bit */
  unsigned int flags;     /* Extra particular characteristics, see PROTOPT_* */
};

#define PROTOPT_NONE 0             /* nothing extra */
#define PROTOPT_SSL (1<<0)         /* uses SSL */
#define PROTOPT_DUAL (1<<1)        /* this protocol uses two connections */
#define PROTOPT_CLOSEACTION (1<<2) /* need action before socket close */
/* some protocols will have to call the underlying functions without regard to
   what exact state the socket signals. IE even if the socket says "readable",
   the send function might need to be called while uploading, or vice versa.
*/
#define PROTOPT_DIRLOCK (1<<3)
#define PROTOPT_NONETWORK (1<<4)   /* protocol doesn't use the network! */
#define PROTOPT_NEEDSPWD (1<<5)    /* needs a password, and if none is set it
                                      gets a default */
#define PROTOPT_NOURLQUERY (1<<6)   /* protocol can't handle
                                        url query strings (?foo=bar) ! */
#define PROTOPT_CREDSPERREQUEST (1<<7) /* requires login credentials per
                                          request instead of per connection */


/* return the count of bytes sent, or -1 on error */
typedef ssize_t (Curl_send)(struct connectdata *conn, /* connection data */
                            int sockindex,            /* socketindex */
                            const void *buf,          /* data to write */
                            size_t len,               /* max amount to write */
                            CURLcode *err);           /* error to return */

/* return the count of bytes read, or -1 on error */
typedef ssize_t (Curl_recv)(struct connectdata *conn, /* connection data */
                            int sockindex,            /* socketindex */
                            char *buf,                /* store data here */
                            size_t len,               /* max amount to read */
                            CURLcode *err);           /* error to return */

/*
 * The connectdata struct contains all fields and variables that should be
 * unique for an entire connection.
 */
struct connectdata {
  /* 'data' is the CURRENT SessionHandle using this connection -- take great
     caution that this might very well vary between different times this
     connection is used! */
  struct SessionHandle *data;

  /* chunk is for HTTP chunked encoding, but is in the general connectdata
     struct only because we can do just about any protocol through a HTTP proxy
     and a HTTP proxy may in fact respond using chunked encoding */
  struct Curl_chunker chunk;

  curl_closesocket_callback fclosesocket; /* function closing the socket(s) */
  void *closesocket_client;

  bool inuse; /* This is a marker for the connection cache logic. If this is
                 TRUE this handle is being used by an easy handle and cannot
                 be used by any other easy handle without careful
                 consideration (== only for pipelining). */

  /**** Fields set when inited and not modified again */
  long connection_id; /* Contains a unique number to make it easier to
                         track the connections in the log output */

  /* 'dns_entry' is the particular host we use. This points to an entry in the
     DNS cache and it will not get pruned while locked. It gets unlocked in
     Curl_done(). This entry will be NULL if the connection is re-used as then
     there is no name resolve done. */
  struct Curl_dns_entry *dns_entry;

  /* 'ip_addr' is the particular IP we connected to. It points to a struct
     within the DNS cache, so this pointer is only valid as long as the DNS
     cache entry remains locked. It gets unlocked in Curl_done() */
  Curl_addrinfo *ip_addr;
  Curl_addrinfo *tempaddr[2]; /* for happy eyeballs */

  /* 'ip_addr_str' is the ip_addr data as a human readable string.
     It remains available as long as the connection does, which is longer than
     the ip_addr itself. */
  char ip_addr_str[MAX_IPADR_LEN];

  unsigned int scope;    /* address scope for IPv6 */

  int socktype;  /* SOCK_STREAM or SOCK_DGRAM */

  struct hostname host;
  struct hostname proxy;

  long port;       /* which port to use locally */
  int remote_port; /* what remote port to connect to, not the proxy port! */

  /* 'primary_ip' and 'primary_port' get filled with peer's numerical
     ip address and port number whenever an outgoing connection is
     *attempted* from the primary socket to a remote address. When more
     than one address is tried for a connection these will hold data
     for the last attempt. When the connection is actually established
     these are updated with data which comes directly from the socket. */

  char primary_ip[MAX_IPADR_LEN];
  long primary_port;

  /* 'local_ip' and 'local_port' get filled with local's numerical
     ip address and port number whenever an outgoing connection is
     **established** from the primary socket to a remote address. */

  char local_ip[MAX_IPADR_LEN];
  long local_port;

  char *user;    /* user name string, allocated */
  char *passwd;  /* password string, allocated */
  char *options; /* options string, allocated */

  char *xoauth2_bearer; /* bearer token for xoauth2, allocated */

  char *proxyuser;    /* proxy user name string, allocated */
  char *proxypasswd;  /* proxy password string, allocated */
  curl_proxytype proxytype; /* what kind of proxy that is in use */

  int httpversion;        /* the HTTP version*10 reported by the server */
  int rtspversion;        /* the RTSP version*10 reported by the server */

  struct timeval now;     /* "current" time */
  struct timeval created; /* creation time */
  curl_socket_t sock[2]; /* two sockets, the second is used for the data
                            transfer when doing FTP */
  curl_socket_t tempsock[2]; /* temporary sockets for happy eyeballs */
  bool sock_accepted[2]; /* TRUE if the socket on this index was created with
                            accept() */
  Curl_recv *recv[2];
  Curl_send *send[2];

  struct ssl_connect_data ssl[2]; /* this is for ssl-stuff */
  struct ssl_config_data ssl_config;

  struct ConnectBits bits;    /* various state-flags for this connection */

 /* connecttime: when connect() is called on the current IP address. Used to
    be able to track when to move on to try next IP - but only when the multi
    interface is used. */
  struct timeval connecttime;
  /* The two fields below get set in Curl_connecthost */
  int num_addr; /* number of addresses to try to connect to */
  long timeoutms_per_addr; /* how long time in milliseconds to spend on
                              trying to connect to each IP address */

  const struct Curl_handler *handler; /* Connection's protocol handler */
  const struct Curl_handler *given;   /* The protocol first given */

  long ip_version; /* copied from the SessionHandle at creation time */

  /**** curl_get() phase fields */

  curl_socket_t sockfd;   /* socket to read from or CURL_SOCKET_BAD */
  curl_socket_t writesockfd; /* socket to write to, it may very
                                well be the same we read from.
                                CURL_SOCKET_BAD disables */

  /** Dynamicly allocated strings, MUST be freed before this **/
  /** struct is killed.                                      **/
  struct dynamically_allocated_data {
    char *proxyuserpwd;
    char *uagent;
    char *accept_encoding;
    char *userpwd;
    char *rangeline;
    char *ref;
    char *host;
    char *cookiehost;
    char *rtsp_transport;
    char *te; /* TE: request header */
  } allocptr;

  int sec_complete; /* if kerberos is enabled for this connection */
#ifdef HAVE_GSSAPI
  enum protection_level command_prot;
  enum protection_level data_prot;
  enum protection_level request_data_prot;
  size_t buffer_size;
  struct krb5buffer in_buffer;
  void *app_data;
  const struct Curl_sec_client_mech *mech;
  struct sockaddr_in local_addr;
#endif

  /* the two following *_inuse fields are only flags, not counters in any way.
     If TRUE it means the channel is in use, and if FALSE it means the channel
     is up for grabs by one. */

  bool readchannel_inuse;  /* whether the read channel is in use by an easy
                              handle */
  bool writechannel_inuse; /* whether the write channel is in use by an easy
                              handle */
  struct curl_llist *send_pipe; /* List of handles waiting to
                                   send on this pipeline */
  struct curl_llist *recv_pipe; /* List of handles waiting to read
                                   their responses on this pipeline */
  char* master_buffer; /* The master buffer allocated on-demand;
                          used for pipelining. */
  size_t read_pos; /* Current read position in the master buffer */
  size_t buf_len; /* Length of the buffer?? */


  curl_seek_callback seek_func; /* function that seeks the input */
  void *seek_client;            /* pointer to pass to the seek() above */

  /*************** Request - specific items ************/

  /* previously this was in the urldata struct */
  curl_read_callback fread_func; /* function that reads the input */
  void *fread_in;           /* pointer to pass to the fread() above */