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1 #ifndef HEADER_CURL_PINGPONG_H
2 #define HEADER_CURL_PINGPONG_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 1998 - 2020, 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 #include "curl_setup.h"
26 
27 #if !defined(CURL_DISABLE_IMAP) || !defined(CURL_DISABLE_FTP) || \
28   !defined(CURL_DISABLE_POP3) || !defined(CURL_DISABLE_SMTP)
29 #define USE_PINGPONG
30 #endif
31 
32 /* forward-declaration, this is defined in urldata.h */
33 struct connectdata;
34 
35 typedef enum {
36   FTPTRANSFER_BODY, /* yes do transfer a body */
37   FTPTRANSFER_INFO, /* do still go through to get info/headers */
38   FTPTRANSFER_NONE, /* don't get anything and don't get info */
39   FTPTRANSFER_LAST  /* end of list marker, never used */
40 } curl_pp_transfer;
41 
42 /*
43  * 'pingpong' is the generic struct used for protocols doing server<->client
44  * conversations in a back-and-forth style such as FTP, IMAP, POP3, SMTP etc.
45  *
46  * It holds response cache and non-blocking sending data.
47  */
48 struct pingpong {
49   char *cache;     /* data cache between getresponse()-calls */
50   size_t cache_size;  /* size of cache in bytes */
51   size_t nread_resp;  /* number of bytes currently read of a server response */
52   char *linestart_resp; /* line start pointer for the server response
53                            reader function */
54   bool pending_resp;  /* set TRUE when a server response is pending or in
55                          progress, and is cleared once the last response is
56                          read */
57   char *sendthis; /* allocated pointer to a buffer that is to be sent to the
58                      server */
59   size_t sendleft; /* number of bytes left to send from the sendthis buffer */
60   size_t sendsize; /* total size of the sendthis buffer */
61   struct curltime response; /* set to Curl_now() when a command has been sent
62                                off, used to time-out response reading */
63   timediff_t response_time; /* When no timeout is given, this is the amount of
64                                milliseconds we await for a server response. */
65   struct connectdata *conn; /* points to the connectdata struct that this
66                                belongs to */
67   struct dynbuf sendbuf;
68 
69   /* Function pointers the protocols MUST implement and provide for the
70      pingpong layer to function */
71 
72   CURLcode (*statemach_act)(struct connectdata *conn);
73 
74   bool (*endofresp)(struct connectdata *conn, char *ptr, size_t len,
75                     int *code);
76 };
77 
78 /*
79  * Curl_pp_statemach()
80  *
81  * called repeatedly until done. Set 'wait' to make it wait a while on the
82  * socket if there's no traffic.
83  */
84 CURLcode Curl_pp_statemach(struct pingpong *pp, bool block,
85                            bool disconnecting);
86 
87 /* initialize stuff to prepare for reading a fresh new response */
88 void Curl_pp_init(struct pingpong *pp);
89 
90 /* setup for the transfer */
91 void Curl_pp_setup(struct pingpong *pp);
92 
93 /* Returns timeout in ms. 0 or negative number means the timeout has already
94    triggered */
95 timediff_t Curl_pp_state_timeout(struct pingpong *pp, bool disconnecting);
96 
97 
98 /***********************************************************************
99  *
100  * Curl_pp_sendf()
101  *
102  * Send the formatted string as a command to a pingpong server. Note that
103  * the string should not have any CRLF appended, as this function will
104  * append the necessary things itself.
105  *
106  * made to never block
107  */
108 CURLcode Curl_pp_sendf(struct pingpong *pp,
109                        const char *fmt, ...);
110 
111 /***********************************************************************
112  *
113  * Curl_pp_vsendf()
114  *
115  * Send the formatted string as a command to a pingpong server. Note that
116  * the string should not have any CRLF appended, as this function will
117  * append the necessary things itself.
118  *
119  * made to never block
120  */
121 CURLcode Curl_pp_vsendf(struct pingpong *pp,
122                         const char *fmt,
123                         va_list args);
124 
125 /*
126  * Curl_pp_readresp()
127  *
128  * Reads a piece of a server response.
129  */
130 CURLcode Curl_pp_readresp(curl_socket_t sockfd,
131                           struct pingpong *pp,
132                           int *code, /* return the server code if done */
133                           size_t *size); /* size of the response */
134 
135 
136 CURLcode Curl_pp_flushsend(struct pingpong *pp);
137 
138 /* call this when a pingpong connection is disconnected */
139 CURLcode Curl_pp_disconnect(struct pingpong *pp);
140 
141 int Curl_pp_getsock(struct pingpong *pp, curl_socket_t *socks);
142 
143 
144 /***********************************************************************
145  *
146  * Curl_pp_moredata()
147  *
148  * Returns whether there are still more data in the cache and so a call
149  * to Curl_pp_readresp() will not block.
150  */
151 bool Curl_pp_moredata(struct pingpong *pp);
152 
153 #endif /* HEADER_CURL_PINGPONG_H */
154