1 #ifndef HEADER_CURL_URLDATA_H
2 #define HEADER_CURL_URLDATA_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
11  *
12  * This software is licensed as described in the file COPYING, which
13  * you should have received as part of this distribution. The terms
14  * are also available at https://curl.haxx.se/docs/copyright.html.
15  *
16  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
17  * copies of the Software, and permit persons to whom the Software is
18  * furnished to do so, under the terms of the COPYING file.
19  *
20  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21  * KIND, either express or implied.
22  *
23  ***************************************************************************/
24 
25 /* This file is for lib internal stuff */
26 
27 #include "curl_setup.h"
28 
29 #define PORT_FTP 21
30 #define PORT_FTPS 990
31 #define PORT_TELNET 23
32 #define PORT_HTTP 80
33 #define PORT_HTTPS 443
34 #define PORT_DICT 2628
35 #define PORT_LDAP 389
36 #define PORT_LDAPS 636
37 #define PORT_TFTP 69
38 #define PORT_SSH 22
39 #define PORT_IMAP 143
40 #define PORT_IMAPS 993
41 #define PORT_POP3 110
42 #define PORT_POP3S 995
43 #define PORT_SMB 445
44 #define PORT_SMBS 445
45 #define PORT_SMTP 25
46 #define PORT_SMTPS 465 /* sometimes called SSMTP */
47 #define PORT_RTSP 554
48 #define PORT_RTMP 1935
49 #define PORT_RTMPT PORT_HTTP
50 #define PORT_RTMPS PORT_HTTPS
51 #define PORT_GOPHER 70
52 
53 #define DICT_MATCH "/MATCH:"
54 #define DICT_MATCH2 "/M:"
55 #define DICT_MATCH3 "/FIND:"
56 #define DICT_DEFINE "/DEFINE:"
57 #define DICT_DEFINE2 "/D:"
58 #define DICT_DEFINE3 "/LOOKUP:"
59 
60 #define CURL_DEFAULT_USER "anonymous"
61 #define CURL_DEFAULT_PASSWORD "ftp@example.com"
62 
63 /* Convenience defines for checking protocols or their SSL based version. Each
64    protocol handler should only ever have a single CURLPROTO_ in its protocol
65    field. */
66 #define PROTO_FAMILY_HTTP (CURLPROTO_HTTP|CURLPROTO_HTTPS)
67 #define PROTO_FAMILY_FTP  (CURLPROTO_FTP|CURLPROTO_FTPS)
68 #define PROTO_FAMILY_POP3 (CURLPROTO_POP3|CURLPROTO_POP3S)
69 #define PROTO_FAMILY_SMB  (CURLPROTO_SMB|CURLPROTO_SMBS)
70 #define PROTO_FAMILY_SMTP (CURLPROTO_SMTP|CURLPROTO_SMTPS)
71 #define PROTO_FAMILY_SSH  (CURLPROTO_SCP|CURLPROTO_SFTP)
72 
73 #define DEFAULT_CONNCACHE_SIZE 5
74 
75 /* length of longest IPv6 address string including the trailing null */
76 #define MAX_IPADR_LEN sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")
77 
78 /* Default FTP/IMAP etc response timeout in milliseconds.
79    Symbian OS panics when given a timeout much greater than 1/2 hour.
80 */
81 #define RESP_TIMEOUT (120*1000)
82 
83 /* Max string intput length is a precaution against abuse and to detect junk
84    input easier and better. */
85 #define CURL_MAX_INPUT_LENGTH 8000000
86 
87 #include "cookie.h"
88 #include "psl.h"
89 #include "formdata.h"
90 
91 #ifdef HAVE_NETINET_IN_H
92 #include <netinet/in.h>
93 #endif
94 #ifdef HAVE_NETINET_IN6_H
95 #include <netinet/in6.h>
96 #endif
97 
98 #include "timeval.h"
99 
100 #include <curl/curl.h>
101 
102 #include "http_chunks.h" /* for the structs and enum stuff */
103 #include "hostip.h"
104 #include "hash.h"
105 #include "splay.h"
106 
107 /* return the count of bytes sent, or -1 on error */
108 typedef ssize_t (Curl_send)(struct connectdata *conn, /* connection data */
109                             int sockindex,            /* socketindex */
110                             const void *buf,          /* data to write */
111                             size_t len,               /* max amount to write */
112                             CURLcode *err);           /* error to return */
113 
114 /* return the count of bytes read, or -1 on error */
115 typedef ssize_t (Curl_recv)(struct connectdata *conn, /* connection data */
116                             int sockindex,            /* socketindex */
117                             char *buf,                /* store data here */
118                             size_t len,               /* max amount to read */
119                             CURLcode *err);           /* error to return */
120 
121 #include "mime.h"
122 #include "imap.h"
123 #include "pop3.h"
124 #include "smtp.h"
125 #include "ftp.h"
126 #include "file.h"
127 #include "vssh/ssh.h"
128 #include "http.h"
129 #include "rtsp.h"
130 #include "smb.h"
131 #include "wildcard.h"
132 #include "multihandle.h"
133 #include "quic.h"
134 
135 #ifdef HAVE_GSSAPI
136 # ifdef HAVE_GSSGNU
137 #  include <gss.h>
138 # elif defined HAVE_GSSAPI_GSSAPI_H
139 #  include <gssapi/gssapi.h>
140 # else
141 #  include <gssapi.h>
142 # endif
143 # ifdef HAVE_GSSAPI_GSSAPI_GENERIC_H
144 #  include <gssapi/gssapi_generic.h>
145 # endif
146 #endif
147 
148 #ifdef HAVE_LIBSSH2_H
149 #include <libssh2.h>
150 #include <libssh2_sftp.h>
151 #endif /* HAVE_LIBSSH2_H */
152 
153 /* Initial size of the buffer to store headers in, it'll be enlarged in case
154    of need. */
155 #define HEADERSIZE 256
156 
157 #define CURLEASY_MAGIC_NUMBER 0xc0dedbadU
158 #define GOOD_EASY_HANDLE(x) \
159   ((x) && ((x)->magic == CURLEASY_MAGIC_NUMBER))
160 
161 /* the type we use for storing a single boolean bit */
162 #ifdef _MSC_VER
163 typedef bool bit;
164 #define BIT(x) bool x
165 #else
166 typedef unsigned int bit;
167 #define BIT(x) bit x:1
168 #endif
169 
170 #ifdef HAVE_GSSAPI
171 /* Types needed for krb5-ftp connections */
172 struct krb5buffer {
173   void *data;
174   size_t size;
175   size_t index;
176   BIT(eof_flag);
177 };
178 
179 enum protection_level {
180   PROT_NONE, /* first in list */
181   PROT_CLEAR,
182   PROT_SAFE,
183   PROT_CONFIDENTIAL,
184   PROT_PRIVATE,
185   PROT_CMD,
186   PROT_LAST /* last in list */
187 };
188 #endif
189 
190 /* enum for the nonblocking SSL connection state machine */
191 typedef enum {
192   ssl_connect_1,
193   ssl_connect_2,
194   ssl_connect_2_reading,
195   ssl_connect_2_writing,
196   ssl_connect_3,
197   ssl_connect_done
198 } ssl_connect_state;
199 
200 typedef enum {
201   ssl_connection_none,
202   ssl_connection_negotiating,
203   ssl_connection_complete
204 } ssl_connection_state;
205 
206 /* SSL backend-specific data; declared differently by each SSL backend */
207 struct ssl_backend_data;
208 
209 /* struct for data related to each SSL connection */
210 struct ssl_connect_data {
211   /* Use ssl encrypted communications TRUE/FALSE, not necessarily using it atm
212      but at least asked to or meaning to use it. See 'state' for the exact
213      current state of the connection. */
214   ssl_connection_state state;
215   ssl_connect_state connecting_state;
216 #if defined(USE_SSL)
217   struct ssl_backend_data *backend;
218 #endif
219   BIT(use);
220 };
221 
222 struct ssl_primary_config {
223   long version;          /* what version the client wants to use */
224   long version_max;      /* max supported version the client wants to use*/
225   char *CApath;          /* certificate dir (doesn't work on windows) */
226   char *CAfile;          /* certificate to verify peer against */
227   char *clientcert;
228   char *random_file;     /* path to file containing "random" data */
229   char *egdsocket;       /* path to file containing the EGD daemon socket */
230   char *cipher_list;     /* list of ciphers to use */
231   char *cipher_list13;   /* list of TLS 1.3 cipher suites to use */
232   char *pinned_key;
233   BIT(verifypeer);       /* set TRUE if this is desired */
234   BIT(verifyhost);       /* set TRUE if CN/SAN must match hostname */
235   BIT(verifystatus);     /* set TRUE if certificate status must be checked */
236   BIT(sessionid);        /* cache session IDs or not */
237 };
238 
239 struct ssl_config_data {
240   struct ssl_primary_config primary;
241   long certverifyresult; /* result from the certificate verification */
242   char *CRLfile;   /* CRL to check certificate revocation */
243   char *issuercert;/* optional issuer certificate filename */
244   curl_ssl_ctx_callback fsslctx; /* function to initialize ssl ctx */
245   void *fsslctxp;        /* parameter for call back */
246   char *cert; /* client certificate file name */
247   char *cert_type; /* format for certificate (default: PEM)*/
248   char *key; /* private key file name */
249   char *key_type; /* format for private key (default: PEM) */
250   char *key_passwd; /* plain text private key password */
251 #ifdef USE_TLS_SRP
252   char *username; /* TLS username (for, e.g., SRP) */
253   char *password; /* TLS password (for, e.g., SRP) */
254   enum CURL_TLSAUTH authtype; /* TLS authentication type (default SRP) */
255 #endif
256   BIT(certinfo);     /* gather lots of certificate info */
257   BIT(falsestart);
258   BIT(enable_beast); /* allow this flaw for interoperability's sake*/
259   BIT(no_revoke);    /* disable SSL certificate revocation checks */
260   BIT(no_partialchain); /* don't accept partial certificate chains */
261 };
262 
263 struct ssl_general_config {
264   size_t max_ssl_sessions; /* SSL session id cache size */
265 };
266 
267 /* information stored about one single SSL session */
268 struct curl_ssl_session {
269   char *name;       /* host name for which this ID was used */
270   char *conn_to_host; /* host name for the connection (may be NULL) */
271   const char *scheme; /* protocol scheme used */
272   void *sessionid;  /* as returned from the SSL layer */
273   size_t idsize;    /* if known, otherwise 0 */
274   long age;         /* just a number, the higher the more recent */
275   int remote_port;  /* remote port */
276   int conn_to_port; /* remote port for the connection (may be -1) */
277   struct ssl_primary_config ssl_config; /* setup for this session */
278 };
279 
280 #ifdef USE_WINDOWS_SSPI
281 #include "curl_sspi.h"
282 #endif
283 
284 /* Struct used for Digest challenge-response authentication */
285 struct digestdata {
286 #if defined(USE_WINDOWS_SSPI)
287   BYTE *input_token;
288   size_t input_token_len;
289   CtxtHandle *http_context;
290   /* copy of user/passwd used to make the identity for http_context.
291      either may be NULL. */
292   char *user;
293   char *passwd;
294 #else
295   char *nonce;
296   char *cnonce;
297   char *realm;
298   int algo;
299   char *opaque;
300   char *qop;
301   char *algorithm;
302   int nc; /* nounce count */
303   BIT(stale); /* set true for re-negotiation */
304   BIT(userhash);
305 #endif
306 };
307 
308 typedef enum {
309   NTLMSTATE_NONE,
310   NTLMSTATE_TYPE1,
311   NTLMSTATE_TYPE2,
312   NTLMSTATE_TYPE3,
313   NTLMSTATE_LAST
314 } curlntlm;
315 
316 typedef enum {
317   GSS_AUTHNONE,
318   GSS_AUTHRECV,
319   GSS_AUTHSENT,
320   GSS_AUTHDONE,
321   GSS_AUTHSUCC
322 } curlnegotiate;
323 
324 #if defined(CURL_DOES_CONVERSIONS) && defined(HAVE_ICONV)
325 #include <iconv.h>
326 #endif
327 
328 /* Struct used for GSSAPI (Kerberos V5) authentication */
329 #if defined(USE_KERBEROS5)
330 struct kerberos5data {
331 #if defined(USE_WINDOWS_SSPI)
332   CredHandle *credentials;
333   CtxtHandle *context;
334   TCHAR *spn;
335   SEC_WINNT_AUTH_IDENTITY identity;
336   SEC_WINNT_AUTH_IDENTITY *p_identity;
337   size_t token_max;
338   BYTE *output_token;
339 #else
340   gss_ctx_id_t context;
341   gss_name_t spn;
342 #endif
343 };
344 #endif
345 
346 /* Struct used for NTLM challenge-response authentication */
347 #if defined(USE_NTLM)
348 struct ntlmdata {
349 #ifdef USE_WINDOWS_SSPI
350 /* The sslContext is used for the Schannel bindings. The
351  * api is available on the Windows 7 SDK and later.
352  */
353 #ifdef SECPKG_ATTR_ENDPOINT_BINDINGS
354   CtxtHandle *sslContext;
355 #endif
356   CredHandle *credentials;
357   CtxtHandle *context;
358   SEC_WINNT_AUTH_IDENTITY identity;
359   SEC_WINNT_AUTH_IDENTITY *p_identity;
360   size_t token_max;
361   BYTE *output_token;
362   BYTE *input_token;
363   size_t input_token_len;
364   TCHAR *spn;
365 #else
366   unsigned int flags;
367   unsigned char nonce[8];
368   void *target_info; /* TargetInfo received in the ntlm type-2 message */
369   unsigned int target_info_len;
370 #endif
371 };
372 #endif
373 
374 /* Struct used for Negotiate (SPNEGO) authentication */
375 #ifdef USE_SPNEGO
376 struct negotiatedata {
377 #ifdef HAVE_GSSAPI
378   OM_uint32 status;
379   gss_ctx_id_t context;
380   gss_name_t spn;
381   gss_buffer_desc output_token;
382 #else
383 #ifdef USE_WINDOWS_SSPI
384 #ifdef SECPKG_ATTR_ENDPOINT_BINDINGS
385   CtxtHandle *sslContext;
386 #endif
387   DWORD status;
388   CredHandle *credentials;
389   CtxtHandle *context;
390   SEC_WINNT_AUTH_IDENTITY identity;
391   SEC_WINNT_AUTH_IDENTITY *p_identity;
392   TCHAR *spn;
393   size_t token_max;
394   BYTE *output_token;
395   size_t output_token_length;
396 #endif
397 #endif
398   BIT(noauthpersist);
399   BIT(havenoauthpersist);
400   BIT(havenegdata);
401   BIT(havemultiplerequests);
402 };
403 #endif
404 
405 
406 /*
407  * Boolean values that concerns this connection.
408  */
409 struct ConnectBits {
410   /* always modify bits.close with the connclose() and connkeep() macros! */
411   bool proxy_ssl_connected[2]; /* TRUE when SSL initialization for HTTPS proxy
412                                   is complete */
413   bool tcpconnect[2]; /* the TCP layer (or similar) is connected, this is set
414                          the first time on the first connect function call */
415   BIT(close); /* if set, we close the connection after this request */
416   BIT(reuse); /* if set, this is a re-used connection */
417   BIT(altused); /* this is an alt-svc "redirect" */
418   BIT(conn_to_host); /* if set, this connection has a "connect to host"
419                         that overrides the host in the URL */
420   BIT(conn_to_port); /* if set, this connection has a "connect to port"
421                         that overrides the port in the URL (remote port) */
422   BIT(proxy); /* if set, this transfer is done through a proxy - any type */
423   BIT(httpproxy);  /* if set, this transfer is done through a http proxy */
424   BIT(socksproxy); /* if set, this transfer is done through a socks proxy */
425   BIT(user_passwd); /* do we use user+password for this connection? */
426   BIT(proxy_user_passwd); /* user+password for the proxy? */
427   BIT(ipv6_ip); /* we communicate with a remote site specified with pure IPv6
428                    IP address */
429   BIT(ipv6);    /* we communicate with a site using an IPv6 address */
430   BIT(do_more); /* this is set TRUE if the ->curl_do_more() function is
431                    supposed to be called, after ->curl_do() */
432   BIT(protoconnstart);/* the protocol layer has STARTED its operation after
433                          the TCP layer connect */
434   BIT(retry);         /* this connection is about to get closed and then
435                          re-attempted at another connection. */
436   BIT(tunnel_proxy);  /* if CONNECT is used to "tunnel" through the proxy.
437                          This is implicit when SSL-protocols are used through
438                          proxies, but can also be enabled explicitly by
439                          apps */
440   BIT(authneg);       /* TRUE when the auth phase has started, which means
441                          that we are creating a request with an auth header,
442                          but it is not the final request in the auth
443                          negotiation. */
444   BIT(rewindaftersend);/* TRUE when the sending couldn't be stopped even
445                           though it will be discarded. When the whole send
446                           operation is done, we must call the data rewind
447                           callback. */
448 #ifndef CURL_DISABLE_FTP
449   BIT(ftp_use_epsv);  /* As set with CURLOPT_FTP_USE_EPSV, but if we find out
450                          EPSV doesn't work we disable it for the forthcoming
451                          requests */
452   BIT(ftp_use_eprt);  /* As set with CURLOPT_FTP_USE_EPRT, but if we find out
453                          EPRT doesn't work we disable it for the forthcoming
454                          requests */
455   BIT(ftp_use_data_ssl); /* Enabled SSL for the data connection */
456 #endif
457   BIT(netrc);         /* name+password provided by netrc */
458   BIT(userpwd_in_url); /* name+password found in url */
459   BIT(stream_was_rewound); /* The stream was rewound after a request read
460                               past the end of its response byte boundary */
461   BIT(proxy_connect_closed); /* TRUE if a proxy disconnected the connection
462                                 in a CONNECT request with auth, so that
463                                 libcurl should reconnect and continue. */
464   BIT(bound); /* set true if bind() has already been done on this socket/
465                  connection */
466   BIT(type_set);  /* type= was used in the URL */
467   BIT(multiplex); /* connection is multiplexed */
468   BIT(tcp_fastopen); /* use TCP Fast Open */
469   BIT(tls_enable_npn);  /* TLS NPN extension? */
470   BIT(tls_enable_alpn); /* TLS ALPN extension? */
471   BIT(socksproxy_connecting); /* connecting through a socks proxy */
472   BIT(connect_only);
473 };
474 
475 struct hostname {
476   char *rawalloc; /* allocated "raw" version of the name */
477   char *encalloc; /* allocated IDN-encoded version of the name */
478   char *name;     /* name to use internally, might be encoded, might be raw */
479   const char *dispname; /* name to display, as 'name' might be encoded */
480 };
481 
482 /*
483  * Flags on the keepon member of the Curl_transfer_keeper
484  */
485 
486 #define KEEP_NONE  0
487 #define KEEP_RECV  (1<<0)     /* there is or may be data to read */
488 #define KEEP_SEND (1<<1)     /* there is or may be data to write */
489 #define KEEP_RECV_HOLD (1<<2) /* when set, no reading should be done but there
490                                  might still be data to read */
491 #define KEEP_SEND_HOLD (1<<3) /* when set, no writing should be done but there
492                                   might still be data to write */
493 #define KEEP_RECV_PAUSE (1<<4) /* reading is paused */
494 #define KEEP_SEND_PAUSE (1<<5) /* writing is paused */
495 
496 #define KEEP_RECVBITS (KEEP_RECV | KEEP_RECV_HOLD | KEEP_RECV_PAUSE)
497 #define KEEP_SENDBITS (KEEP_SEND | KEEP_SEND_HOLD | KEEP_SEND_PAUSE)
498 
499 struct Curl_async {
500   char *hostname;
501   int port;
502   struct Curl_dns_entry *dns;
503   int status; /* if done is TRUE, this is the status from the callback */
504   void *os_specific;  /* 'struct thread_data' for Windows */
505   BIT(done);  /* set TRUE when the lookup is complete */
506 };
507 
508 #define FIRSTSOCKET     0
509 #define SECONDARYSOCKET 1
510 
511 /* These function pointer types are here only to allow easier typecasting
512    within the source when we need to cast between data pointers (such as NULL)
513    and function pointers. */
514 typedef CURLcode (*Curl_do_more_func)(struct connectdata *, int *);
515 typedef CURLcode (*Curl_done_func)(struct connectdata *, CURLcode, bool);
516 
517 enum expect100 {
518   EXP100_SEND_DATA,           /* enough waiting, just send the body now */
519   EXP100_AWAITING_CONTINUE,   /* waiting for the 100 Continue header */
520   EXP100_SENDING_REQUEST,     /* still sending the request but will wait for
521                                  the 100 header once done with the request */
522   EXP100_FAILED               /* used on 417 Expectation Failed */
523 };
524 
525 enum upgrade101 {
526   UPGR101_INIT,               /* default state */
527   UPGR101_REQUESTED,          /* upgrade requested */
528   UPGR101_RECEIVED,           /* response received */
529   UPGR101_WORKING             /* talking upgraded protocol */
530 };
531 
532 enum doh_slots {
533   /* Explicit values for first two symbols so as to match hard-coded
534    * constants in existing code
535    */
536   DOH_PROBE_SLOT_IPADDR_V4 = 0, /* make 'V4' stand out for readability */
537   DOH_PROBE_SLOT_IPADDR_V6 = 1, /* 'V6' likewise */
538 
539   /* Space here for (possibly build-specific) additional slot definitions */
540 
541   /* for example */
542   /* #ifdef WANT_DOH_FOOBAR_TXT */
543   /*   DOH_PROBE_SLOT_FOOBAR_TXT, */
544   /* #endif */
545 
546   /* AFTER all slot definitions, establish how many we have */
547   DOH_PROBE_SLOTS
548 };
549 
550 struct dohresponse {
551   unsigned char *memory;
552   size_t size;
553 };
554 
555 /* one of these for each DoH request */
556 struct dnsprobe {
557   CURL *easy;
558   int dnstype;
559   unsigned char dohbuffer[512];
560   size_t dohlen;
561   struct dohresponse serverdoh;
562 };
563 
564 struct dohdata {
565   struct curl_slist *headers;
566   struct dnsprobe probe[DOH_PROBE_SLOTS];
567   unsigned int pending; /* still outstanding requests */
568   const char *host;
569   int port;
570 };
571 
572 /*
573  * Request specific data in the easy handle (Curl_easy).  Previously,
574  * these members were on the connectdata struct but since a conn struct may
575  * now be shared between different Curl_easys, we store connection-specific
576  * data here. This struct only keeps stuff that's interesting for *this*
577  * request, as it will be cleared between multiple ones
578  */
579 struct SingleRequest {
580   curl_off_t size;        /* -1 if unknown at this point */
581   curl_off_t maxdownload; /* in bytes, the maximum amount of data to fetch,
582                              -1 means unlimited */
583   curl_off_t bytecount;         /* total number of bytes read */
584   curl_off_t writebytecount;    /* number of bytes written */
585 
586   curl_off_t headerbytecount;   /* only count received headers */
587   curl_off_t deductheadercount; /* this amount of bytes doesn't count when we
588                                    check if anything has been transferred at
589                                    the end of a connection. We use this
590                                    counter to make only a 100 reply (without a
591                                    following second response code) result in a
592                                    CURLE_GOT_NOTHING error code */
593 
594   struct curltime start;         /* transfer started at this time */
595   struct curltime now;           /* current time */
596   enum {
597     HEADER_NORMAL,              /* no bad header at all */
598     HEADER_PARTHEADER,          /* part of the chunk is a bad header, the rest
599                                    is normal data */
600     HEADER_ALLBAD               /* all was believed to be header */
601   } badheader;                  /* the header was deemed bad and will be
602                                    written as body */
603   int headerline;               /* counts header lines to better track the
604                                    first one */
605   char *hbufp;                  /* points at *end* of header line */
606   size_t hbuflen;
607   char *str;                    /* within buf */
608   char *str_start;              /* within buf */
609   char *end_ptr;                /* within buf */
610   char *p;                      /* within headerbuff */
611   curl_off_t offset;            /* possible resume offset read from the
612                                    Content-Range: header */
613   int httpcode;                 /* error code from the 'HTTP/1.? XXX' or
614                                    'RTSP/1.? XXX' line */
615   struct curltime start100;      /* time stamp to wait for the 100 code from */
616   enum expect100 exp100;        /* expect 100 continue state */
617   enum upgrade101 upgr101;      /* 101 upgrade state */
618 
619   struct contenc_writer_s *writer_stack;  /* Content unencoding stack. */
620                                           /* See sec 3.5, RFC2616. */
621   time_t timeofdoc;
622   long bodywrites;
623   char *buf;
624   int keepon;
625   char *location;   /* This points to an allocated version of the Location:
626                        header data */
627   char *newurl;     /* Set to the new URL to use when a redirect or a retry is
628                        wanted */
629 
630   /* 'upload_present' is used to keep a byte counter of how much data there is
631      still left in the buffer, aimed for upload. */
632   ssize_t upload_present;
633 
634   /* 'upload_fromhere' is used as a read-pointer when we uploaded parts of a
635      buffer, so the next read should read from where this pointer points to,
636      and the 'upload_present' contains the number of bytes available at this
637      position */
638   char *upload_fromhere;
639   void *protop;       /* Allocated protocol-specific data. Each protocol
640                          handler makes sure this points to data it needs. */
641 #ifndef CURL_DISABLE_DOH
642   struct dohdata doh; /* DoH specific data for this request */
643 #endif
644   BIT(header);       /* incoming data has HTTP header */
645   BIT(content_range); /* set TRUE if Content-Range: was found */
646   BIT(upload_done);  /* set to TRUE when doing chunked transfer-encoding
647                         upload and we're uploading the last chunk */
648   BIT(ignorebody);   /* we read a response-body but we ignore it! */
649   BIT(http_bodyless); /* HTTP response status code is between 100 and 199,
650                          204 or 304 */
651   BIT(chunk); /* if set, this is a chunked transfer-encoding */
652   BIT(upload_chunky); /* set TRUE if we are doing chunked transfer-encoding
653                          on upload */
654   BIT(getheader);    /* TRUE if header parsing is wanted */
655   BIT(forbidchunk);  /* used only to explicitly forbid chunk-upload for
656                         specific upload buffers. See readmoredata() in http.c
657                         for details. */
658 };
659 
660 /*
661  * Specific protocol handler.
662  */
663 
664 struct Curl_handler {
665   const char *scheme;        /* URL scheme name. */
666 
667   /* Complement to setup_connection_internals(). */
668   CURLcode (*setup_connection)(struct connectdata *);
669 
670   /* These two functions MUST be set to be protocol dependent */
671   CURLcode (*do_it)(struct connectdata *, bool *done);
672   Curl_done_func done;
673 
674   /* If the curl_do() function is better made in two halves, this
675    * curl_do_more() function will be called afterwards, if set. For example
676    * for doing the FTP stuff after the PASV/PORT command.
677    */
678   Curl_do_more_func do_more;
679 
680   /* This function *MAY* be set to a protocol-dependent function that is run
681    * after the connect() and everything is done, as a step in the connection.
682    * The 'done' pointer points to a bool that should be set to TRUE if the
683    * function completes before return. If it doesn't complete, the caller
684    * should call the curl_connecting() function until it is.
685    */
686   CURLcode (*connect_it)(struct connectdata *, bool *done);
687 
688   /* See above. */
689   CURLcode (*connecting)(struct connectdata *, bool *done);
690   CURLcode (*doing)(struct connectdata *, bool *done);
691 
692   /* Called from the multi interface during the PROTOCONNECT phase, and it
693      should then return a proper fd set */
694   int (*proto_getsock)(struct connectdata *conn,
695                        curl_socket_t *socks);
696 
697   /* Called from the multi interface during the DOING phase, and it should
698      then return a proper fd set */
699   int (*doing_getsock)(struct connectdata *conn,
700                        curl_socket_t *socks);
701 
702   /* Called from the multi interface during the DO_MORE phase, and it should
703      then return a proper fd set */
704   int (*domore_getsock)(struct connectdata *conn,
705                         curl_socket_t *socks);
706 
707   /* Called from the multi interface during the DO_DONE, PERFORM and
708      WAITPERFORM phases, and it should then return a proper fd set. Not setting
709      this will make libcurl use the generic default one. */
710   int (*perform_getsock)(const struct connectdata *conn,
711                          curl_socket_t *socks);
712 
713   /* This function *MAY* be set to a protocol-dependent function that is run
714    * by the curl_disconnect(), as a step in the disconnection.  If the handler
715    * is called because the connection has been considered dead, dead_connection
716    * is set to TRUE.
717    */
718   CURLcode (*disconnect)(struct connectdata *, bool dead_connection);
719 
720   /* If used, this function gets called from transfer.c:readwrite_data() to
721      allow the protocol to do extra reads/writes */
722   CURLcode (*readwrite)(struct Curl_easy *data, struct connectdata *conn,
723                         ssize_t *nread, bool *readmore);
724 
725   /* This function can perform various checks on the connection. See
726      CONNCHECK_* for more information about the checks that can be performed,
727      and CONNRESULT_* for the results that can be returned. */
728   unsigned int (*connection_check)(struct connectdata *conn,
729                                    unsigned int checks_to_perform);
730 
731   long defport;           /* Default port. */
732   unsigned int protocol;  /* See CURLPROTO_* - this needs to be the single
733                              specific protocol bit */
734   unsigned int flags;     /* Extra particular characteristics, see PROTOPT_* */
735 };
736 
737 #define PROTOPT_NONE 0             /* nothing extra */
738 #define PROTOPT_SSL (1<<0)         /* uses SSL */
739 #define PROTOPT_DUAL (1<<1)        /* this protocol uses two connections */
740 #define PROTOPT_CLOSEACTION (1<<2) /* need action before socket close */
741 /* some protocols will have to call the underlying functions without regard to
742    what exact state the socket signals. IE even if the socket says "readable",
743    the send function might need to be called while uploading, or vice versa.
744 */
745 #define PROTOPT_DIRLOCK (1<<3)
746 #define PROTOPT_NONETWORK (1<<4)   /* protocol doesn't use the network! */
747 #define PROTOPT_NEEDSPWD (1<<5)    /* needs a password, and if none is set it
748                                       gets a default */
749 #define PROTOPT_NOURLQUERY (1<<6)   /* protocol can't handle
750                                         url query strings (?foo=bar) ! */
751 #define PROTOPT_CREDSPERREQUEST (1<<7) /* requires login credentials per
752                                           request instead of per connection */
753 #define PROTOPT_ALPN_NPN (1<<8) /* set ALPN and/or NPN for this */
754 #define PROTOPT_STREAM (1<<9) /* a protocol with individual logical streams */
755 #define PROTOPT_URLOPTIONS (1<<10) /* allow options part in the userinfo field
756                                       of the URL */
757 #define PROTOPT_PROXY_AS_HTTP (1<<11) /* allow this non-HTTP scheme over a
758                                          HTTP proxy as HTTP proxies may know
759                                          this protocol and act as a gateway */
760 #define PROTOPT_WILDCARD (1<<12) /* protocol supports wildcard matching */
761 
762 #define CONNCHECK_NONE 0                 /* No checks */
763 #define CONNCHECK_ISDEAD (1<<0)          /* Check if the connection is dead. */
764 #define CONNCHECK_KEEPALIVE (1<<1)       /* Perform any keepalive function. */
765 
766 #define CONNRESULT_NONE 0                /* No extra information. */
767 #define CONNRESULT_DEAD (1<<0)           /* The connection is dead. */
768 
769 #ifdef USE_RECV_BEFORE_SEND_WORKAROUND
770 struct postponed_data {
771   char *buffer;          /* Temporal store for received data during
772                             sending, must be freed */
773   size_t allocated_size; /* Size of temporal store */
774   size_t recv_size;      /* Size of received data during sending */
775   size_t recv_processed; /* Size of processed part of postponed data */
776 #ifdef DEBUGBUILD
777   curl_socket_t bindsock;/* Structure must be bound to specific socket,
778                             used only for DEBUGASSERT */
779 #endif /* DEBUGBUILD */
780 };
781 #endif /* USE_RECV_BEFORE_SEND_WORKAROUND */
782 
783 struct proxy_info {
784   struct hostname host;
785   long port;
786   curl_proxytype proxytype; /* what kind of proxy that is in use */
787   char *user;    /* proxy user name string, allocated */
788   char *passwd;  /* proxy password string, allocated */
789 };
790 
791 #define CONNECT_BUFFER_SIZE 16384
792 
793 /* struct for HTTP CONNECT state data */
794 struct http_connect_state {
795   char connect_buffer[CONNECT_BUFFER_SIZE];
796   int perline; /* count bytes per line */
797   int keepon;
798   char *line_start;
799   char *ptr; /* where to store more data */
800   curl_off_t cl; /* size of content to read and ignore */
801   enum {
802     TUNNEL_INIT,    /* init/default/no tunnel state */
803     TUNNEL_CONNECT, /* CONNECT has been sent off */
804     TUNNEL_COMPLETE /* CONNECT response received completely */
805   } tunnel_state;
806   BIT(chunked_encoding);
807   BIT(close_connection);
808 };
809 
810 struct ldapconninfo;
811 
812 /*
813  * The connectdata struct contains all fields and variables that should be
814  * unique for an entire connection.
815  */
816 struct connectdata {
817   /* 'data' is the CURRENT Curl_easy using this connection -- take great
818      caution that this might very well vary between different times this
819      connection is used! */
820   struct Curl_easy *data;
821 
822   struct curl_llist_element bundle_node; /* conncache */
823 
824   /* chunk is for HTTP chunked encoding, but is in the general connectdata
825      struct only because we can do just about any protocol through a HTTP proxy
826      and a HTTP proxy may in fact respond using chunked encoding */
827   struct Curl_chunker chunk;
828 
829   curl_closesocket_callback fclosesocket; /* function closing the socket(s) */
830   void *closesocket_client;
831 
832   /* This is used by the connection cache logic. If this returns TRUE, this
833      handle is still used by one or more easy handles and can only used by any
834      other easy handle without careful consideration (== only for
835      multiplexing) and it cannot be used by another multi handle! */
836 #define CONN_INUSE(c) ((c)->easyq.size)
837 
838   /**** Fields set when inited and not modified again */
839   long connection_id; /* Contains a unique number to make it easier to
840                          track the connections in the log output */
841 
842   /* 'dns_entry' is the particular host we use. This points to an entry in the
843      DNS cache and it will not get pruned while locked. It gets unlocked in
844      Curl_done(). This entry will be NULL if the connection is re-used as then
845      there is no name resolve done. */
846   struct Curl_dns_entry *dns_entry;
847 
848   /* 'ip_addr' is the particular IP we connected to. It points to a struct
849      within the DNS cache, so this pointer is only valid as long as the DNS
850      cache entry remains locked. It gets unlocked in Curl_done() */
851   Curl_addrinfo *ip_addr;
852   Curl_addrinfo *tempaddr[2]; /* for happy eyeballs */
853 
854   /* 'ip_addr_str' is the ip_addr data as a human readable string.
855      It remains available as long as the connection does, which is longer than
856      the ip_addr itself. */
857   char ip_addr_str[MAX_IPADR_LEN];
858 
859   unsigned int scope_id;  /* Scope id for IPv6 */
860 
861   enum {
862     TRNSPRT_TCP = 3,
863     TRNSPRT_UDP = 4,
864     TRNSPRT_QUIC = 5
865   } transport;
866 
867 #ifdef ENABLE_QUIC
868   struct quicsocket hequic[2]; /* two, for happy eyeballs! */
869   struct quicsocket *quic;
870 #endif
871 
872   struct hostname host;
873   char *hostname_resolve; /* host name to resolve to address, allocated */
874   char *secondaryhostname; /* secondary socket host name (ftp) */
875   struct hostname conn_to_host; /* the host to connect to. valid only if
876                                    bits.conn_to_host is set */
877 
878   struct proxy_info socks_proxy;
879   struct proxy_info http_proxy;
880 
881   long port;       /* which port to use locally */
882   int remote_port; /* the remote port, not the proxy port! */
883   int conn_to_port; /* the remote port to connect to. valid only if
884                        bits.conn_to_port is set */
885   unsigned short secondary_port; /* secondary socket remote port to connect to
886                                     (ftp) */
887 
888   /* 'primary_ip' and 'primary_port' get filled with peer's numerical
889      ip address and port number whenever an outgoing connection is
890      *attempted* from the primary socket to a remote address. When more
891      than one address is tried for a connection these will hold data
892      for the last attempt. When the connection is actually established
893      these are updated with data which comes directly from the socket. */
894 
895   char primary_ip[MAX_IPADR_LEN];
896   long primary_port;
897 
898   /* 'local_ip' and 'local_port' get filled with local's numerical
899      ip address and port number whenever an outgoing connection is
900      **established** from the primary socket to a remote address. */
901 
902   char local_ip[MAX_IPADR_LEN];
903   long local_port;
904 
905   char *user;    /* user name string, allocated */
906   char *passwd;  /* password string, allocated */
907   char *options; /* options string, allocated */
908 
909   char *oauth_bearer;     /* bearer token for OAuth 2.0, allocated */
910   char *sasl_authzid;     /* authorisation identity string, allocated */
911 
912   int httpversion;        /* the HTTP version*10 reported by the server */
913   int rtspversion;        /* the RTSP version*10 reported by the server */
914 
915   struct curltime now;     /* "current" time */
916   struct curltime created; /* creation time */
917   struct curltime lastused; /* when returned to the connection cache */
918   curl_socket_t sock[2]; /* two sockets, the second is used for the data
919                             transfer when doing FTP */
920   curl_socket_t tempsock[2]; /* temporary sockets for happy eyeballs */
921   bool sock_accepted[2]; /* TRUE if the socket on this index was created with
922                             accept() */
923   Curl_recv *recv[2];
924   Curl_send *send[2];
925 
926 #ifdef USE_RECV_BEFORE_SEND_WORKAROUND
927   struct postponed_data postponed[2]; /* two buffers for two sockets */
928 #endif /* USE_RECV_BEFORE_SEND_WORKAROUND */
929   struct ssl_connect_data ssl[2]; /* this is for ssl-stuff */
930   struct ssl_connect_data proxy_ssl[2]; /* this is for proxy ssl-stuff */
931 #ifdef USE_SSL
932   void *ssl_extra; /* separately allocated backend-specific data */
933 #endif
934   struct ssl_primary_config ssl_config;
935   struct ssl_primary_config proxy_ssl_config;
936   struct ConnectBits bits;    /* various state-flags for this connection */
937 
938  /* connecttime: when connect() is called on the current IP address. Used to
939     be able to track when to move on to try next IP - but only when the multi
940     interface is used. */
941   struct curltime connecttime;
942   /* The two fields below get set in Curl_connecthost */
943   int num_addr; /* number of addresses to try to connect to */
944   timediff_t timeoutms_per_addr; /* how long time in milliseconds to spend on
945                                     trying to connect to each IP address */
946 
947   const struct Curl_handler *handler; /* Connection's protocol handler */
948   const struct Curl_handler *given;   /* The protocol first given */
949 
950   long ip_version; /* copied from the Curl_easy at creation time */
951 
952   /* Protocols can use a custom keepalive mechanism to keep connections alive.
953      This allows those protocols to track the last time the keepalive mechanism
954      was used on this connection. */
955   struct curltime keepalive;
956 
957   long upkeep_interval_ms;      /* Time between calls for connection upkeep. */
958 
959   /**** curl_get() phase fields */
960 
961   curl_socket_t sockfd;   /* socket to read from or CURL_SOCKET_BAD */
962   curl_socket_t writesockfd; /* socket to write to, it may very
963                                 well be the same we read from.
964                                 CURL_SOCKET_BAD disables */
965 
966   /** Dynamically allocated strings, MUST be freed before this **/
967   /** struct is killed.                                      **/
968   struct dynamically_allocated_data {
969     char *proxyuserpwd;
970     char *uagent;
971     char *accept_encoding;
972     char *userpwd;
973     char *rangeline;
974     char *ref;
975     char *host;
976     char *cookiehost;
977     char *rtsp_transport;
978     char *te; /* TE: request header */
979   } allocptr;
980 
981 #ifdef HAVE_GSSAPI
982   BIT(sec_complete); /* if Kerberos is enabled for this connection */
983   enum protection_level command_prot;
984   enum protection_level data_prot;
985   enum protection_level request_data_prot;
986   size_t buffer_size;
987   struct krb5buffer in_buffer;
988   void *app_data;
989   const struct Curl_sec_client_mech *mech;
990   struct sockaddr_in local_addr;
991 #endif
992 
993 #if defined(USE_KERBEROS5)    /* Consider moving some of the above GSS-API */
994   struct kerberos5data krb5;  /* variables into the structure definition, */
995 #endif                        /* however, some of them are ftp specific. */
996 
997   struct curl_llist easyq;    /* List of easy handles using this connection */
998   curl_seek_callback seek_func; /* function that seeks the input */
999   void *seek_client;            /* pointer to pass to the seek() above */
1000 
1001   /*************** Request - specific items ************/
1002 #if defined(USE_WINDOWS_SSPI) && defined(SECPKG_ATTR_ENDPOINT_BINDINGS)
1003   CtxtHandle *sslContext;
1004 #endif
1005 
1006 #if defined(USE_NTLM)
1007   curlntlm http_ntlm_state;
1008   curlntlm proxy_ntlm_state;
1009 
1010   struct ntlmdata ntlm;     /* NTLM differs from other authentication schemes
1011                                because it authenticates connections, not
1012                                single requests! */
1013   struct ntlmdata proxyntlm; /* NTLM data for proxy */
1014 
1015 #if defined(NTLM_WB_ENABLED)
1016   /* used for communication with Samba's winbind daemon helper ntlm_auth */
1017   curl_socket_t ntlm_auth_hlpr_socket;
1018   pid_t ntlm_auth_hlpr_pid;
1019   char *challenge_header;
1020   char *response_header;
1021 #endif
1022 #endif
1023 
1024 #ifdef USE_SPNEGO
1025   curlnegotiate http_negotiate_state;
1026   curlnegotiate proxy_negotiate_state;
1027 
1028   struct negotiatedata negotiate; /* state data for host Negotiate auth */
1029   struct negotiatedata proxyneg; /* state data for proxy Negotiate auth */
1030 #endif
1031 
1032   /* data used for the asynch name resolve callback */
1033   struct Curl_async async;
1034 
1035   /* These three are used for chunked-encoding trailer support */
1036   char *trailer; /* allocated buffer to store trailer in */
1037   int trlMax;    /* allocated buffer size */
1038   int trlPos;    /* index of where to store data */
1039 
1040   union {
1041     struct ftp_conn ftpc;
1042     struct http_conn httpc;
1043     struct ssh_conn sshc;
1044     struct tftp_state_data *tftpc;
1045     struct imap_conn imapc;
1046     struct pop3_conn pop3c;
1047     struct smtp_conn smtpc;
1048     struct rtsp_conn rtspc;
1049     struct smb_conn smbc;
1050     void *rtmp;
1051     struct ldapconninfo *ldapc;
1052   } proto;
1053 
1054   int cselect_bits; /* bitmask of socket events */
1055   int waitfor;      /* current READ/WRITE bits to wait for */
1056 
1057 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
1058   int socks5_gssapi_enctype;
1059 #endif
1060 
1061   /* When this connection is created, store the conditions for the local end
1062      bind. This is stored before the actual bind and before any connection is
1063      made and will serve the purpose of being used for comparison reasons so
1064      that subsequent bound-requested connections aren't accidentally re-using
1065      wrong connections. */
1066   char *localdev;
1067   unsigned short localport;
1068   int localportrange;
1069   struct http_connect_state *connect_state; /* for HTTP CONNECT */
1070   struct connectbundle *bundle; /* The bundle we are member of */
1071   int negnpn; /* APLN or NPN TLS negotiated protocol, CURL_HTTP_VERSION* */
1072 
1073 #ifdef USE_UNIX_SOCKETS
1074   char *unix_domain_socket;
1075   BIT(abstract_unix_socket);
1076 #endif
1077   BIT(tls_upgraded);
1078   /* the two following *_inuse fields are only flags, not counters in any way.
1079      If TRUE it means the channel is in use, and if FALSE it means the channel
1080      is up for grabs by one. */
1081   BIT(readchannel_inuse);  /* whether the read channel is in use by an easy
1082                               handle */
1083   BIT(writechannel_inuse); /* whether the write channel is in use by an easy
1084                               handle */
1085 };
1086 
1087 /* The end of connectdata. */
1088 
1089 /*
1090  * Struct to keep statistical and informational data.
1091  * All variables in this struct must be initialized/reset in Curl_initinfo().
1092  */
1093 struct PureInfo {
1094   int httpcode;  /* Recent HTTP, FTP, RTSP or SMTP response code */
1095   int httpproxycode; /* response code from proxy when received separate */
1096   int httpversion; /* the http version number X.Y = X*10+Y */
1097   time_t filetime; /* If requested, this is might get set. Set to -1 if the
1098                       time was unretrievable. */
1099   curl_off_t header_size;  /* size of read header(s) in bytes */
1100   curl_off_t request_size; /* the amount of bytes sent in the request(s) */
1101   unsigned long proxyauthavail; /* what proxy auth types were announced */
1102   unsigned long httpauthavail;  /* what host auth types were announced */
1103   long numconnects; /* how many new connection did libcurl created */
1104   char *contenttype; /* the content type of the object */
1105   char *wouldredirect; /* URL this would've been redirected to if asked to */
1106   curl_off_t retry_after; /* info from Retry-After: header */
1107 
1108   /* PureInfo members 'conn_primary_ip', 'conn_primary_port', 'conn_local_ip'
1109      and, 'conn_local_port' are copied over from the connectdata struct in
1110      order to allow curl_easy_getinfo() to return this information even when
1111      the session handle is no longer associated with a connection, and also
1112      allow curl_easy_reset() to clear this information from the session handle
1113      without disturbing information which is still alive, and that might be
1114      reused, in the connection cache. */
1115 
1116   char conn_primary_ip[MAX_IPADR_LEN];
1117   long conn_primary_port;
1118   char conn_local_ip[MAX_IPADR_LEN];
1119   long conn_local_port;
1120   const char *conn_scheme;
1121   unsigned int conn_protocol;
1122   struct curl_certinfo certs; /* info about the certs, only populated in
1123                                  OpenSSL, GnuTLS, Schannel, NSS and GSKit
1124                                  builds. Asked for with CURLOPT_CERTINFO
1125                                  / CURLINFO_CERTINFO */
1126   BIT(timecond);  /* set to TRUE if the time condition didn't match, which
1127                      thus made the document NOT get fetched */
1128 };
1129 
1130 
1131 struct Progress {
1132   time_t lastshow; /* time() of the last displayed progress meter or NULL to
1133                       force redraw at next call */
1134   curl_off_t size_dl; /* total expected size */
1135   curl_off_t size_ul; /* total expected size */
1136   curl_off_t downloaded; /* transferred so far */
1137   curl_off_t uploaded; /* transferred so far */
1138 
1139   curl_off_t current_speed; /* uses the currently fastest transfer */
1140 
1141   int width; /* screen width at download start */
1142   int flags; /* see progress.h */
1143 
1144   timediff_t timespent;
1145 
1146   curl_off_t dlspeed;
1147   curl_off_t ulspeed;
1148 
1149   timediff_t t_nslookup;
1150   timediff_t t_connect;
1151   timediff_t t_appconnect;
1152   timediff_t t_pretransfer;
1153   timediff_t t_starttransfer;
1154   timediff_t t_redirect;
1155 
1156   struct curltime start;
1157   struct curltime t_startsingle;
1158   struct curltime t_startop;
1159   struct curltime t_acceptdata;
1160 
1161 
1162   /* upload speed limit */
1163   struct curltime ul_limit_start;
1164   curl_off_t ul_limit_size;
1165   /* download speed limit */
1166   struct curltime dl_limit_start;
1167   curl_off_t dl_limit_size;
1168 
1169 #define CURR_TIME (5 + 1) /* 6 entries for 5 seconds */
1170 
1171   curl_off_t speeder[ CURR_TIME ];
1172   struct curltime speeder_time[ CURR_TIME ];
1173   int speeder_c;
1174   BIT(callback);  /* set when progress callback is used */
1175   BIT(is_t_startransfer_set);
1176 };
1177 
1178 typedef enum {
1179   HTTPREQ_NONE, /* first in list */
1180   HTTPREQ_GET,
1181   HTTPREQ_POST,
1182   HTTPREQ_POST_FORM, /* we make a difference internally */
1183   HTTPREQ_POST_MIME, /* we make a difference internally */
1184   HTTPREQ_PUT,
1185   HTTPREQ_HEAD,
1186   HTTPREQ_OPTIONS,
1187   HTTPREQ_LAST /* last in list */
1188 } Curl_HttpReq;
1189 
1190 typedef enum {
1191     RTSPREQ_NONE, /* first in list */
1192     RTSPREQ_OPTIONS,
1193     RTSPREQ_DESCRIBE,
1194     RTSPREQ_ANNOUNCE,
1195     RTSPREQ_SETUP,
1196     RTSPREQ_PLAY,
1197     RTSPREQ_PAUSE,
1198     RTSPREQ_TEARDOWN,
1199     RTSPREQ_GET_PARAMETER,
1200     RTSPREQ_SET_PARAMETER,
1201     RTSPREQ_RECORD,
1202     RTSPREQ_RECEIVE,
1203     RTSPREQ_LAST /* last in list */
1204 } Curl_RtspReq;
1205 
1206 /*
1207  * Values that are generated, temporary or calculated internally for a
1208  * "session handle" must be defined within the 'struct UrlState'.  This struct
1209  * will be used within the Curl_easy struct. When the 'Curl_easy'
1210  * struct is cloned, this data MUST NOT be copied.
1211  *
1212  * Remember that any "state" information goes globally for the curl handle.
1213  * Session-data MUST be put in the connectdata struct and here.  */
1214 #define MAX_CURL_USER_LENGTH 256
1215 #define MAX_CURL_PASSWORD_LENGTH 256
1216 
1217 struct auth {
1218   unsigned long want;  /* Bitmask set to the authentication methods wanted by
1219                           app (with CURLOPT_HTTPAUTH or CURLOPT_PROXYAUTH). */
1220   unsigned long picked;
1221   unsigned long avail; /* Bitmask for what the server reports to support for
1222                           this resource */
1223   BIT(done);  /* TRUE when the auth phase is done and ready to do the
1224                  actual request */
1225   BIT(multipass); /* TRUE if this is not yet authenticated but within the
1226                      auth multipass negotiation */
1227   BIT(iestyle); /* TRUE if digest should be done IE-style or FALSE if it
1228                    should be RFC compliant */
1229 };
1230 
1231 struct Curl_http2_dep {
1232   struct Curl_http2_dep *next;
1233   struct Curl_easy *data;
1234 };
1235 
1236 /*
1237  * This struct is for holding data that was attempted to get sent to the user's
1238  * callback but is held due to pausing. One instance per type (BOTH, HEADER,
1239  * BODY).
1240  */
1241 struct tempbuf {
1242   char *buf;  /* allocated buffer to keep data in when a write callback
1243                  returns to make the connection paused */
1244   size_t len; /* size of the 'tempwrite' allocated buffer */
1245   int type;   /* type of the 'tempwrite' buffer as a bitmask that is used with
1246                  Curl_client_write() */
1247 };
1248 
1249 /* Timers */
1250 typedef enum {
1251   EXPIRE_100_TIMEOUT,
1252   EXPIRE_ASYNC_NAME,
1253   EXPIRE_CONNECTTIMEOUT,
1254   EXPIRE_DNS_PER_NAME,
1255   EXPIRE_HAPPY_EYEBALLS_DNS, /* See asyn-ares.c */
1256   EXPIRE_HAPPY_EYEBALLS,
1257   EXPIRE_MULTI_PENDING,
1258   EXPIRE_RUN_NOW,
1259   EXPIRE_SPEEDCHECK,
1260   EXPIRE_TIMEOUT,
1261   EXPIRE_TOOFAST,
1262   EXPIRE_QUIC,
1263   EXPIRE_LAST /* not an actual timer, used as a marker only */
1264 } expire_id;
1265 
1266 
1267 typedef enum {
1268   TRAILERS_NONE,
1269   TRAILERS_INITIALIZED,
1270   TRAILERS_SENDING,
1271   TRAILERS_DONE
1272 } trailers_state;
1273 
1274 
1275 /*
1276  * One instance for each timeout an easy handle can set.
1277  */
1278 struct time_node {
1279   struct curl_llist_element list;
1280   struct curltime time;
1281   expire_id eid;
1282 };
1283 
1284 /* individual pieces of the URL */
1285 struct urlpieces {
1286   char *scheme;
1287   char *hostname;
1288   char *port;
1289   char *user;
1290   char *password;
1291   char *options;
1292   char *path;
1293   char *query;
1294 };
1295 
1296 struct UrlState {
1297 
1298   /* Points to the connection cache */
1299   struct conncache *conn_cache;
1300 
1301   /* buffers to store authentication data in, as parsed from input options */
1302   struct curltime keeps_speed; /* for the progress meter really */
1303 
1304   struct connectdata *lastconnect; /* The last connection, NULL if undefined */
1305 
1306   char *headerbuff; /* allocated buffer to store headers in */
1307   size_t headersize;   /* size of the allocation */
1308 
1309   char *buffer; /* download buffer */
1310   char *ulbuf; /* allocated upload buffer or NULL */
1311   curl_off_t current_speed;  /* the ProgressShow() function sets this,
1312                                 bytes / second */
1313   char *first_host; /* host name of the first (not followed) request.
1314                        if set, this should be the host name that we will
1315                        sent authorization to, no else. Used to make Location:
1316                        following not keep sending user+password... This is
1317                        strdup() data.
1318                     */
1319   int first_remote_port; /* remote port of the first (not followed) request */
1320   struct curl_ssl_session *session; /* array of 'max_ssl_sessions' size */
1321   long sessionage;                  /* number of the most recent session */
1322   unsigned int tempcount; /* number of entries in use in tempwrite, 0 - 3 */
1323   struct tempbuf tempwrite[3]; /* BOTH, HEADER, BODY */
1324   char *scratch; /* huge buffer[set.buffer_size*2] for upload CRLF replacing */
1325   int os_errno;  /* filled in with errno whenever an error occurs */
1326 #ifdef HAVE_SIGNAL
1327   /* storage for the previous bag^H^H^HSIGPIPE signal handler :-) */
1328   void (*prev_signal)(int sig);
1329 #endif
1330   struct digestdata digest;      /* state data for host Digest auth */
1331   struct digestdata proxydigest; /* state data for proxy Digest auth */
1332 
1333   struct auth authhost;  /* auth details for host */
1334   struct auth authproxy; /* auth details for proxy */
1335   void *resolver; /* resolver state, if it is used in the URL state -
1336                      ares_channel f.e. */
1337 
1338 #if defined(USE_OPENSSL)
1339   /* void instead of ENGINE to avoid bleeding OpenSSL into this header */
1340   void *engine;
1341 #endif /* USE_OPENSSL */
1342   struct curltime expiretime; /* set this with Curl_expire() only */
1343   struct Curl_tree timenode; /* for the splay stuff */
1344   struct curl_llist timeoutlist; /* list of pending timeouts */
1345   struct time_node expires[EXPIRE_LAST]; /* nodes for each expire type */
1346 
1347   /* a place to store the most recently set FTP entrypath */
1348   char *most_recent_ftp_entrypath;
1349 
1350   int httpversion;       /* the lowest HTTP version*10 reported by any server
1351                             involved in this request */
1352 
1353 #if !defined(WIN32) && !defined(MSDOS) && !defined(__EMX__) && \
1354     !defined(__SYMBIAN32__)
1355 /* do FTP line-end conversions on most platforms */
1356 #define CURL_DO_LINEEND_CONV
1357   /* for FTP downloads: track CRLF sequences that span blocks */
1358   BIT(prev_block_had_trailing_cr);
1359   /* for FTP downloads: how many CRLFs did we converted to LFs? */
1360   curl_off_t crlf_conversions;
1361 #endif
1362   char *range; /* range, if used. See README for detailed specification on
1363                   this syntax. */
1364   curl_off_t resume_from; /* continue [ftp] transfer from here */
1365 
1366   /* This RTSP state information survives requests and connections */
1367   long rtsp_next_client_CSeq; /* the session's next client CSeq */
1368   long rtsp_next_server_CSeq; /* the session's next server CSeq */
1369   long rtsp_CSeq_recv; /* most recent CSeq received */
1370 
1371   curl_off_t infilesize; /* size of file to upload, -1 means unknown.
1372                             Copied from set.filesize at start of operation */
1373 
1374   size_t drain; /* Increased when this stream has data to read, even if its
1375                    socket is not necessarily is readable. Decreased when
1376                    checked. */
1377 
1378   curl_read_callback fread_func; /* read callback/function */
1379   void *in;                      /* CURLOPT_READDATA */
1380 
1381   struct Curl_easy *stream_depends_on;
1382   int stream_weight;
1383   CURLU *uh; /* URL handle for the current parsed URL */
1384   struct urlpieces up;
1385 #ifndef CURL_DISABLE_HTTP
1386   size_t trailers_bytes_sent;
1387   Curl_send_buffer *trailers_buf; /* a buffer containing the compiled trailing
1388                                   headers */
1389 #endif
1390   trailers_state trailers_state; /* whether we are sending trailers
1391                                        and what stage are we at */
1392 #ifdef CURLDEBUG
1393   BIT(conncache_lock);
1394 #endif
1395   /* when curl_easy_perform() is called, the multi handle is "owned" by
1396      the easy handle so curl_easy_cleanup() on such an easy handle will
1397      also close the multi handle! */
1398   BIT(multi_owned_by_easy);
1399 
1400   BIT(this_is_a_follow); /* this is a followed Location: request */
1401   BIT(refused_stream); /* this was refused, try again */
1402   BIT(errorbuf); /* Set to TRUE if the error buffer is already filled in.
1403                     This must be set to FALSE every time _easy_perform() is
1404                     called. */
1405   BIT(allow_port); /* Is set.use_port allowed to take effect or not. This
1406                       is always set TRUE when curl_easy_perform() is called. */
1407   BIT(authproblem); /* TRUE if there's some problem authenticating */
1408   /* set after initial USER failure, to prevent an authentication loop */
1409   BIT(ftp_trying_alternative);
1410   BIT(wildcardmatch); /* enable wildcard matching */
1411   BIT(expect100header);  /* TRUE if we added Expect: 100-continue */
1412   BIT(use_range);
1413   BIT(rangestringalloc); /* the range string is malloc()'ed */
1414   BIT(done); /* set to FALSE when Curl_init_do() is called and set to TRUE
1415                   when multi_done() is called, to prevent multi_done() to get
1416                   invoked twice when the multi interface is used. */
1417   BIT(stream_depends_e); /* set or don't set the Exclusive bit */
1418   BIT(previouslypending); /* this transfer WAS in the multi->pending queue */
1419   BIT(cookie_engine);
1420 };
1421 
1422 
1423 /*
1424  * This 'DynamicStatic' struct defines dynamic states that actually change
1425  * values in the 'UserDefined' area, which MUST be taken into consideration
1426  * if the UserDefined struct is cloned or similar. You can probably just
1427  * copy these, but each one indicate a special action on other data.
1428  */
1429 
1430 struct DynamicStatic {
1431   char *url;        /* work URL, copied from UserDefined */
1432   char *referer;    /* referer string */
1433   struct curl_slist *cookielist; /* list of cookie files set by
1434                                     curl_easy_setopt(COOKIEFILE) calls */
1435   struct curl_slist *resolve; /* set to point to the set.resolve list when
1436                                  this should be dealt with in pretransfer */
1437   BIT(url_alloc);   /* URL string is malloc()'ed */
1438   BIT(referer_alloc); /* referer string is malloc()ed */
1439   BIT(wildcard_resolve); /* Set to true if any resolve change is a
1440                               wildcard */
1441 };
1442 
1443 /*
1444  * This 'UserDefined' struct must only contain data that is set once to go
1445  * for many (perhaps) independent connections. Values that are generated or
1446  * calculated internally for the "session handle" MUST be defined within the
1447  * 'struct UrlState' instead. The only exceptions MUST note the changes in
1448  * the 'DynamicStatic' struct.
1449  * Character pointer fields point to dynamic storage, unless otherwise stated.
1450  */
1451 
1452 struct Curl_multi;    /* declared and used only in multi.c */
1453 
1454 enum dupstring {
1455   STRING_CERT_ORIG,       /* client certificate file name */
1456   STRING_CERT_PROXY,      /* client certificate file name */
1457   STRING_CERT_TYPE_ORIG,  /* format for certificate (default: PEM)*/
1458   STRING_CERT_TYPE_PROXY, /* format for certificate (default: PEM)*/
1459   STRING_COOKIE,          /* HTTP cookie string to send */
1460   STRING_COOKIEJAR,       /* dump all cookies to this file */
1461   STRING_CUSTOMREQUEST,   /* HTTP/FTP/RTSP request/method to use */
1462   STRING_DEFAULT_PROTOCOL, /* Protocol to use when the URL doesn't specify */
1463   STRING_DEVICE,          /* local network interface/address to use */
1464   STRING_ENCODING,        /* Accept-Encoding string */
1465   STRING_FTP_ACCOUNT,     /* ftp account data */
1466   STRING_FTP_ALTERNATIVE_TO_USER, /* command to send if USER/PASS fails */
1467   STRING_FTPPORT,         /* port to send with the FTP PORT command */
1468   STRING_KEY_ORIG,        /* private key file name */
1469   STRING_KEY_PROXY,       /* private key file name */
1470   STRING_KEY_PASSWD_ORIG, /* plain text private key password */
1471   STRING_KEY_PASSWD_PROXY, /* plain text private key password */
1472   STRING_KEY_TYPE_ORIG,   /* format for private key (default: PEM) */
1473   STRING_KEY_TYPE_PROXY,  /* format for private key (default: PEM) */
1474   STRING_KRB_LEVEL,       /* krb security level */
1475   STRING_NETRC_FILE,      /* if not NULL, use this instead of trying to find
1476                              $HOME/.netrc */
1477   STRING_PROXY,           /* proxy to use */
1478   STRING_PRE_PROXY,       /* pre socks proxy to use */
1479   STRING_SET_RANGE,       /* range, if used */
1480   STRING_SET_REFERER,     /* custom string for the HTTP referer field */
1481   STRING_SET_URL,         /* what original URL to work on */
1482   STRING_SSL_CAPATH_ORIG, /* CA directory name (doesn't work on windows) */
1483   STRING_SSL_CAPATH_PROXY, /* CA directory name (doesn't work on windows) */
1484   STRING_SSL_CAFILE_ORIG, /* certificate file to verify peer against */
1485   STRING_SSL_CAFILE_PROXY, /* certificate file to verify peer against */
1486   STRING_SSL_PINNEDPUBLICKEY_ORIG, /* public key file to verify peer against */
1487   STRING_SSL_PINNEDPUBLICKEY_PROXY, /* public key file to verify proxy */
1488   STRING_SSL_CIPHER_LIST_ORIG, /* list of ciphers to use */
1489   STRING_SSL_CIPHER_LIST_PROXY, /* list of ciphers to use */
1490   STRING_SSL_CIPHER13_LIST_ORIG, /* list of TLS 1.3 ciphers to use */
1491   STRING_SSL_CIPHER13_LIST_PROXY, /* list of TLS 1.3 ciphers to use */
1492   STRING_SSL_EGDSOCKET,   /* path to file containing the EGD daemon socket */
1493   STRING_SSL_RANDOM_FILE, /* path to file containing "random" data */
1494   STRING_USERAGENT,       /* User-Agent string */
1495   STRING_SSL_CRLFILE_ORIG, /* crl file to check certificate */
1496   STRING_SSL_CRLFILE_PROXY, /* crl file to check certificate */
1497   STRING_SSL_ISSUERCERT_ORIG, /* issuer cert file to check certificate */
1498   STRING_SSL_ISSUERCERT_PROXY, /* issuer cert file to check certificate */
1499   STRING_SSL_ENGINE,      /* name of ssl engine */
1500   STRING_USERNAME,        /* <username>, if used */
1501   STRING_PASSWORD,        /* <password>, if used */
1502   STRING_OPTIONS,         /* <options>, if used */
1503   STRING_PROXYUSERNAME,   /* Proxy <username>, if used */
1504   STRING_PROXYPASSWORD,   /* Proxy <password>, if used */
1505   STRING_NOPROXY,         /* List of hosts which should not use the proxy, if
1506                              used */
1507   STRING_RTSP_SESSION_ID, /* Session ID to use */
1508   STRING_RTSP_STREAM_URI, /* Stream URI for this request */
1509   STRING_RTSP_TRANSPORT,  /* Transport for this session */
1510 #ifdef USE_SSH
1511   STRING_SSH_PRIVATE_KEY, /* path to the private key file for auth */
1512   STRING_SSH_PUBLIC_KEY,  /* path to the public key file for auth */
1513   STRING_SSH_HOST_PUBLIC_KEY_MD5, /* md5 of host public key in ascii hex */
1514   STRING_SSH_KNOWNHOSTS,  /* file name of knownhosts file */
1515 #endif
1516   STRING_PROXY_SERVICE_NAME, /* Proxy service name */
1517   STRING_SERVICE_NAME,    /* Service name */
1518   STRING_MAIL_FROM,
1519   STRING_MAIL_AUTH,
1520 
1521 #ifdef USE_TLS_SRP
1522   STRING_TLSAUTH_USERNAME_ORIG,  /* TLS auth <username> */
1523   STRING_TLSAUTH_USERNAME_PROXY, /* TLS auth <username> */
1524   STRING_TLSAUTH_PASSWORD_ORIG,  /* TLS auth <password> */
1525   STRING_TLSAUTH_PASSWORD_PROXY, /* TLS auth <password> */
1526 #endif
1527   STRING_BEARER,                /* <bearer>, if used */
1528 #ifdef USE_UNIX_SOCKETS
1529   STRING_UNIX_SOCKET_PATH,      /* path to Unix socket, if used */
1530 #endif
1531   STRING_TARGET,                /* CURLOPT_REQUEST_TARGET */
1532   STRING_DOH,                   /* CURLOPT_DOH_URL */
1533 #ifdef USE_ALTSVC
1534   STRING_ALTSVC,                /* CURLOPT_ALTSVC */
1535 #endif
1536   STRING_SASL_AUTHZID,          /* CURLOPT_SASL_AUTHZID */
1537 #ifndef CURL_DISABLE_PROXY
1538   STRING_TEMP_URL,              /* temp URL storage for proxy use */
1539 #endif
1540   /* -- end of zero-terminated strings -- */
1541 
1542   STRING_LASTZEROTERMINATED,
1543 
1544   /* -- below this are pointers to binary data that cannot be strdup'ed. --- */
1545 
1546   STRING_COPYPOSTFIELDS,  /* if POST, set the fields' values here */
1547 
1548   STRING_LAST /* not used, just an end-of-list marker */
1549 };
1550 
1551 /* callback that gets called when this easy handle is completed within a multi
1552    handle.  Only used for internally created transfers, like for example
1553    DoH. */
1554 typedef int (*multidone_func)(struct Curl_easy *easy, CURLcode result);
1555 
1556 struct UserDefined {
1557   FILE *err;         /* the stderr user data goes here */
1558   void *debugdata;   /* the data that will be passed to fdebug */
1559   char *errorbuffer; /* (Static) store failure messages in here */
1560   long proxyport; /* If non-zero, use this port number by default. If the
1561                      proxy string features a ":[port]" that one will override
1562                      this. */
1563   void *out;         /* CURLOPT_WRITEDATA */
1564   void *in_set;      /* CURLOPT_READDATA */
1565   void *writeheader; /* write the header to this if non-NULL */
1566   void *rtp_out;     /* write RTP to this if non-NULL */
1567   long use_port;     /* which port to use (when not using default) */
1568   unsigned long httpauth;  /* kind of HTTP authentication to use (bitmask) */
1569   unsigned long proxyauth; /* kind of proxy authentication to use (bitmask) */
1570   unsigned long socks5auth;/* kind of SOCKS5 authentication to use (bitmask) */
1571   long followlocation; /* as in HTTP Location: */
1572   long maxredirs;    /* maximum no. of http(s) redirects to follow, set to -1
1573                         for infinity */
1574 
1575   int keep_post;     /* keep POSTs as POSTs after a 30x request; each
1576                         bit represents a request, from 301 to 303 */
1577   void *postfields;  /* if POST, set the fields' values here */
1578   curl_seek_callback seek_func;      /* function that seeks the input */
1579   curl_off_t postfieldsize; /* if POST, this might have a size to use instead
1580                                of strlen(), and then the data *may* be binary
1581                                (contain zero bytes) */
1582   unsigned short localport; /* local port number to bind to */
1583   int localportrange; /* number of additional port numbers to test in case the
1584                          'localport' one can't be bind()ed */
1585   curl_write_callback fwrite_func;   /* function that stores the output */
1586   curl_write_callback fwrite_header; /* function that stores headers */
1587   curl_write_callback fwrite_rtp;    /* function that stores interleaved RTP */
1588   curl_read_callback fread_func_set; /* function that reads the input */
1589   curl_progress_callback fprogress; /* OLD and deprecated progress callback  */
1590   curl_xferinfo_callback fxferinfo; /* progress callback */
1591   curl_debug_callback fdebug;      /* function that write informational data */
1592   curl_ioctl_callback ioctl_func;  /* function for I/O control */
1593   curl_sockopt_callback fsockopt;  /* function for setting socket options */
1594   void *sockopt_client; /* pointer to pass to the socket options callback */
1595   curl_opensocket_callback fopensocket; /* function for checking/translating
1596                                            the address and opening the
1597                                            socket */
1598   void *opensocket_client;
1599   curl_closesocket_callback fclosesocket; /* function for closing the
1600                                              socket */
1601   void *closesocket_client;
1602 
1603   void *seek_client;    /* pointer to pass to the seek callback */
1604   /* the 3 curl_conv_callback functions below are used on non-ASCII hosts */
1605   /* function to convert from the network encoding: */
1606   curl_conv_callback convfromnetwork;
1607   /* function to convert to the network encoding: */
1608   curl_conv_callback convtonetwork;
1609   /* function to convert from UTF-8 encoding: */
1610   curl_conv_callback convfromutf8;
1611 
1612   void *progress_client; /* pointer to pass to the progress callback */
1613   void *ioctl_client;   /* pointer to pass to the ioctl callback */
1614   long timeout;         /* in milliseconds, 0 means no timeout */
1615   long connecttimeout;  /* in milliseconds, 0 means no timeout */
1616   long accepttimeout;   /* in milliseconds, 0 means no timeout */
1617   long happy_eyeballs_timeout; /* in milliseconds, 0 is a valid value */
1618   long server_response_timeout; /* in milliseconds, 0 means no timeout */
1619   long maxage_conn;     /* in seconds, max idle time to allow a connection that
1620                            is to be reused */
1621   long tftp_blksize;    /* in bytes, 0 means use default */
1622   curl_off_t filesize;  /* size of file to upload, -1 means unknown */
1623   long low_speed_limit; /* bytes/second */
1624   long low_speed_time;  /* number of seconds */
1625   curl_off_t max_send_speed; /* high speed limit in bytes/second for upload */
1626   curl_off_t max_recv_speed; /* high speed limit in bytes/second for
1627                                 download */
1628   curl_off_t set_resume_from;  /* continue [ftp] transfer from here */
1629   struct curl_slist *headers; /* linked list of extra headers */
1630   struct curl_slist *proxyheaders; /* linked list of extra CONNECT headers */
1631   struct curl_httppost *httppost;  /* linked list of old POST data */
1632   curl_mimepart mimepost;  /* MIME/POST data. */
1633   struct curl_slist *quote;     /* after connection is established */
1634   struct curl_slist *postquote; /* after the transfer */
1635   struct curl_slist *prequote; /* before the transfer, after type */
1636   struct curl_slist *source_quote;  /* 3rd party quote */
1637   struct curl_slist *source_prequote;  /* in 3rd party transfer mode - before
1638                                           the transfer on source host */
1639   struct curl_slist *source_postquote; /* in 3rd party transfer mode - after
1640                                           the transfer on source host */
1641   struct curl_slist *telnet_options; /* linked list of telnet options */
1642   struct curl_slist *resolve;     /* list of names to add/remove from
1643                                      DNS cache */
1644   struct curl_slist *connect_to; /* list of host:port mappings to override
1645                                     the hostname and port to connect to */
1646   curl_TimeCond timecondition; /* kind of time/date comparison */
1647   time_t timevalue;       /* what time to compare with */
1648   Curl_HttpReq httpreq;   /* what kind of HTTP request (if any) is this */
1649   long httpversion; /* when non-zero, a specific HTTP version requested to
1650                        be used in the library's request(s) */
1651   struct ssl_config_data ssl;  /* user defined SSL stuff */
1652   struct ssl_config_data proxy_ssl;  /* user defined SSL stuff for proxy */
1653   struct ssl_general_config general_ssl; /* general user defined SSL stuff */
1654   curl_proxytype proxytype; /* what kind of proxy that is in use */
1655   long dns_cache_timeout; /* DNS cache timeout */
1656   long buffer_size;      /* size of receive buffer to use */
1657   size_t upload_buffer_size; /* size of upload buffer to use,
1658                                 keep it >= CURL_MAX_WRITE_SIZE */
1659   void *private_data; /* application-private data */
1660   struct curl_slist *http200aliases; /* linked list of aliases for http200 */
1661   long ipver; /* the CURL_IPRESOLVE_* defines in the public header file
1662                  0 - whatever, 1 - v2, 2 - v6 */
1663   curl_off_t max_filesize; /* Maximum file size to download */
1664 #ifndef CURL_DISABLE_FTP
1665   curl_ftpfile ftp_filemethod; /* how to get to a file when FTP is used  */
1666   curl_ftpauth ftpsslauth; /* what AUTH XXX to be attempted */
1667   curl_ftpccc ftp_ccc;   /* FTP CCC options */
1668 #endif
1669   int ftp_create_missing_dirs; /* 1 - create directories that don't exist
1670                                   2 - the same but also allow MKD to fail once
1671                                */
1672   curl_sshkeycallback ssh_keyfunc; /* key matching callback */
1673   void *ssh_keyfunc_userp;         /* custom pointer to callback */
1674   enum CURL_NETRC_OPTION
1675        use_netrc;        /* defined in include/curl.h */
1676   curl_usessl use_ssl;   /* if AUTH TLS is to be attempted etc, for FTP or
1677                             IMAP or POP3 or others! */
1678   long new_file_perms;    /* Permissions to use when creating remote files */
1679   long new_directory_perms; /* Permissions to use when creating remote dirs */
1680   long ssh_auth_types;   /* allowed SSH auth types */
1681   char *str[STRING_LAST]; /* array of strings, pointing to allocated memory */
1682   unsigned int scope_id;  /* Scope id for IPv6 */
1683   long allowed_protocols;
1684   long redir_protocols;
1685   struct curl_slist *mail_rcpt; /* linked list of mail recipients */
1686   /* Common RTSP header options */
1687   Curl_RtspReq rtspreq; /* RTSP request type */
1688   long rtspversion; /* like httpversion, for RTSP */
1689   curl_chunk_bgn_callback chunk_bgn; /* called before part of transfer
1690                                         starts */
1691   curl_chunk_end_callback chunk_end; /* called after part transferring
1692                                         stopped */
1693   curl_fnmatch_callback fnmatch; /* callback to decide which file corresponds
1694                                     to pattern (e.g. if WILDCARDMATCH is on) */
1695   void *fnmatch_data;
1696 
1697   long gssapi_delegation; /* GSS-API credential delegation, see the
1698                              documentation of CURLOPT_GSSAPI_DELEGATION */
1699 
1700   long tcp_keepidle;     /* seconds in idle before sending keepalive probe */
1701   long tcp_keepintvl;    /* seconds between TCP keepalive probes */
1702 
1703   size_t maxconnects;    /* Max idle connections in the connection cache */
1704 
1705   long expect_100_timeout; /* in milliseconds */
1706   struct Curl_easy *stream_depends_on;
1707   int stream_weight;
1708   struct Curl_http2_dep *stream_dependents;
1709 
1710   curl_resolver_start_callback resolver_start; /* optional callback called
1711                                                   before resolver start */
1712   void *resolver_start_client; /* pointer to pass to resolver start callback */
1713   long upkeep_interval_ms;      /* Time between calls for connection upkeep. */
1714   multidone_func fmultidone;
1715   struct Curl_easy *dohfor; /* this is a DoH request for that transfer */
1716   CURLU *uh; /* URL handle for the current parsed URL */
1717   void *trailer_data; /* pointer to pass to trailer data callback */
1718   curl_trailer_callback trailer_callback; /* trailing data callback */
1719   BIT(is_fread_set); /* has read callback been set to non-NULL? */
1720   BIT(is_fwrite_set); /* has write callback been set to non-NULL? */
1721   BIT(free_referer); /* set TRUE if 'referer' points to a string we
1722                         allocated */
1723   BIT(tftp_no_options); /* do not send TFTP options requests */
1724   BIT(sep_headers);     /* handle host and proxy headers separately */
1725   BIT(cookiesession);   /* new cookie session? */
1726   BIT(crlf);            /* convert crlf on ftp upload(?) */
1727   BIT(strip_path_slash); /* strip off initial slash from path */
1728   BIT(ssh_compression);            /* enable SSH compression */
1729 
1730 /* Here follows boolean settings that define how to behave during
1731    this session. They are STATIC, set by libcurl users or at least initially
1732    and they don't change during operations. */
1733   BIT(get_filetime);     /* get the time and get of the remote file */
1734   BIT(tunnel_thru_httpproxy); /* use CONNECT through a HTTP proxy */
1735   BIT(prefer_ascii);     /* ASCII rather than binary */
1736   BIT(ftp_append);       /* append, not overwrite, on upload */
1737   BIT(ftp_list_only);    /* switch FTP command for listing directories */
1738 #ifndef CURL_DISABLE_FTP
1739   BIT(ftp_use_port);     /* use the FTP PORT command */
1740   BIT(ftp_use_epsv);     /* if EPSV is to be attempted or not */
1741   BIT(ftp_use_eprt);     /* if EPRT is to be attempted or not */
1742   BIT(ftp_use_pret);     /* if PRET is to be used before PASV or not */
1743   BIT(ftp_skip_ip);      /* skip the IP address the FTP server passes on to
1744                             us */
1745 #endif
1746   BIT(hide_progress);    /* don't use the progress meter */
1747   BIT(http_fail_on_error);  /* fail on HTTP error codes >= 400 */
1748   BIT(http_keep_sending_on_error); /* for HTTP status codes >= 300 */
1749   BIT(http_follow_location); /* follow HTTP redirects */
1750   BIT(http_transfer_encoding); /* request compressed HTTP transfer-encoding */
1751   BIT(allow_auth_to_other_hosts);
1752   BIT(include_header); /* include received protocol headers in data output */
1753   BIT(http_set_referer); /* is a custom referer used */
1754   BIT(http_auto_referer); /* set "correct" referer when following
1755                              location: */
1756   BIT(opt_no_body);    /* as set with CURLOPT_NOBODY */
1757   BIT(upload);         /* upload request */
1758   BIT(verbose);        /* output verbosity */
1759   BIT(krb);            /* Kerberos connection requested */
1760   BIT(reuse_forbid);   /* forbidden to be reused, close after use */
1761   BIT(reuse_fresh);    /* do not re-use an existing connection  */
1762   BIT(no_signal);      /* do not use any signal/alarm handler */
1763   BIT(tcp_nodelay);    /* whether to enable TCP_NODELAY or not */
1764   BIT(ignorecl);       /* ignore content length */
1765   BIT(connect_only);   /* make connection, let application use the socket */
1766   BIT(http_te_skip);   /* pass the raw body data to the user, even when
1767                           transfer-encoded (chunked, compressed) */
1768   BIT(http_ce_skip);   /* pass the raw body data to the user, even when
1769                           content-encoded (chunked, compressed) */
1770   BIT(proxy_transfer_mode); /* set transfer mode (;type=<a|i>) when doing
1771                                FTP via an HTTP proxy */
1772 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
1773   BIT(socks5_gssapi_nec); /* Flag to support NEC SOCKS5 server */
1774 #endif
1775   BIT(sasl_ir);         /* Enable/disable SASL initial response */
1776   BIT(wildcard_enabled); /* enable wildcard matching */
1777   BIT(tcp_keepalive);  /* use TCP keepalives */
1778   BIT(tcp_fastopen);   /* use TCP Fast Open */
1779   BIT(ssl_enable_npn); /* TLS NPN extension? */
1780   BIT(ssl_enable_alpn);/* TLS ALPN extension? */
1781   BIT(path_as_is);     /* allow dotdots? */
1782   BIT(pipewait);       /* wait for multiplex status before starting a new
1783                           connection */
1784   BIT(suppress_connect_headers); /* suppress proxy CONNECT response headers
1785                                     from user callbacks */
1786   BIT(dns_shuffle_addresses); /* whether to shuffle addresses before use */
1787   BIT(stream_depends_e); /* set or don't set the Exclusive bit */
1788   BIT(haproxyprotocol); /* whether to send HAProxy PROXY protocol v1
1789                            header */
1790   BIT(abstract_unix_socket);
1791   BIT(disallow_username_in_url); /* disallow username in url */
1792   BIT(doh); /* DNS-over-HTTPS enabled */
1793   BIT(doh_get); /* use GET for DoH requests, instead of POST */
1794   BIT(http09_allowed); /* allow HTTP/0.9 responses */
1795 };
1796 
1797 struct Names {
1798   struct curl_hash *hostcache;
1799   enum {
1800     HCACHE_NONE,    /* not pointing to anything */
1801     HCACHE_MULTI,   /* points to a shared one in the multi handle */
1802     HCACHE_SHARED   /* points to a shared one in a shared object */
1803   } hostcachetype;
1804 };
1805 
1806 /*
1807  * The 'connectdata' struct MUST have all the connection oriented stuff as we
1808  * may have several simultaneous connections and connection structs in memory.
1809  *
1810  * The 'struct UserDefined' must only contain data that is set once to go for
1811  * many (perhaps) independent connections. Values that are generated or
1812  * calculated internally for the "session handle" must be defined within the
1813  * 'struct UrlState' instead.
1814  */
1815 
1816 struct Curl_easy {
1817   /* first, two fields for the linked list of these */
1818   struct Curl_easy *next;
1819   struct Curl_easy *prev;
1820 
1821   struct connectdata *conn;
1822   struct curl_llist_element connect_queue;
1823   struct curl_llist_element conn_queue; /* list per connectdata */
1824 
1825   CURLMstate mstate;  /* the handle's state */
1826   CURLcode result;   /* previous result */
1827 
1828   struct Curl_message msg; /* A single posted message. */
1829 
1830   /* Array with the plain socket numbers this handle takes care of, in no
1831      particular order. Note that all sockets are added to the sockhash, where
1832      the state etc are also kept. This array is mostly used to detect when a
1833      socket is to be removed from the hash. See singlesocket(). */
1834   curl_socket_t sockets[MAX_SOCKSPEREASYHANDLE];
1835   int actions[MAX_SOCKSPEREASYHANDLE]; /* action for each socket in
1836                                           sockets[] */
1837   int numsocks;
1838 
1839   struct Names dns;
1840   struct Curl_multi *multi;    /* if non-NULL, points to the multi handle
1841                                   struct to which this "belongs" when used by
1842                                   the multi interface */
1843   struct Curl_multi *multi_easy; /* if non-NULL, points to the multi handle
1844                                     struct to which this "belongs" when used
1845                                     by the easy interface */
1846   struct Curl_share *share;    /* Share, handles global variable mutexing */
1847 #ifdef USE_LIBPSL
1848   struct PslCache *psl;        /* The associated PSL cache. */
1849 #endif
1850   struct SingleRequest req;    /* Request-specific data */
1851   struct UserDefined set;      /* values set by the libcurl user */
1852   struct DynamicStatic change; /* possibly modified userdefined data */
1853   struct CookieInfo *cookies;  /* the cookies, read from files and servers.
1854                                   NOTE that the 'cookie' field in the
1855                                   UserDefined struct defines if the "engine"
1856                                   is to be used or not. */
1857 #ifdef USE_ALTSVC
1858   struct altsvcinfo *asi;      /* the alt-svc cache */
1859 #endif
1860   struct Progress progress;    /* for all the progress meter data */
1861   struct UrlState state;       /* struct for fields used for state info and
1862                                   other dynamic purposes */
1863 #ifndef CURL_DISABLE_FTP
1864   struct WildcardData wildcard; /* wildcard download state info */
1865 #endif
1866   struct PureInfo info;        /* stats, reports and info data */
1867   struct curl_tlssessioninfo tsi; /* Information about the TLS session, only
1868                                      valid after a client has asked for it */
1869 #if defined(CURL_DOES_CONVERSIONS) && defined(HAVE_ICONV)
1870   iconv_t outbound_cd;         /* for translating to the network encoding */
1871   iconv_t inbound_cd;          /* for translating from the network encoding */
1872   iconv_t utf8_cd;             /* for translating to UTF8 */
1873 #endif /* CURL_DOES_CONVERSIONS && HAVE_ICONV */
1874   unsigned int magic;          /* set to a CURLEASY_MAGIC_NUMBER */
1875 };
1876 
1877 #define LIBCURL_NAME "libcurl"
1878 
1879 #endif /* HEADER_CURL_URLDATA_H */
1880