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1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
9  *
10  * This software is licensed as described in the file COPYING, which
11  * you should have received as part of this distribution. The terms
12  * are also available at https://curl.haxx.se/docs/copyright.html.
13  *
14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15  * copies of the Software, and permit persons to whom the Software is
16  * furnished to do so, under the terms of the COPYING file.
17  *
18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19  * KIND, either express or implied.
20  *
21  ***************************************************************************/
22 
23 #include "curl_setup.h"
24 
25 #ifndef CURL_DISABLE_GOPHER
26 
27 #include "urldata.h"
28 #include <curl/curl.h>
29 #include "transfer.h"
30 #include "sendf.h"
31 #include "progress.h"
32 #include "gopher.h"
33 #include "select.h"
34 #include "strdup.h"
35 #include "url.h"
36 #include "escape.h"
37 #include "warnless.h"
38 #include "curl_printf.h"
39 #include "curl_memory.h"
40 /* The last #include file should be: */
41 #include "memdebug.h"
42 
43 /*
44  * Forward declarations.
45  */
46 
47 static CURLcode gopher_do(struct connectdata *conn, bool *done);
48 
49 /*
50  * Gopher protocol handler.
51  * This is also a nice simple template to build off for simple
52  * connect-command-download protocols.
53  */
54 
55 const struct Curl_handler Curl_handler_gopher = {
56   "GOPHER",                             /* scheme */
57   ZERO_NULL,                            /* setup_connection */
58   gopher_do,                            /* do_it */
59   ZERO_NULL,                            /* done */
60   ZERO_NULL,                            /* do_more */
61   ZERO_NULL,                            /* connect_it */
62   ZERO_NULL,                            /* connecting */
63   ZERO_NULL,                            /* doing */
64   ZERO_NULL,                            /* proto_getsock */
65   ZERO_NULL,                            /* doing_getsock */
66   ZERO_NULL,                            /* domore_getsock */
67   ZERO_NULL,                            /* perform_getsock */
68   ZERO_NULL,                            /* disconnect */
69   ZERO_NULL,                            /* readwrite */
70   ZERO_NULL,                            /* connection_check */
71   PORT_GOPHER,                          /* defport */
72   CURLPROTO_GOPHER,                     /* protocol */
73   PROTOPT_NONE                          /* flags */
74 };
75 
gopher_do(struct connectdata * conn,bool * done)76 static CURLcode gopher_do(struct connectdata *conn, bool *done)
77 {
78   CURLcode result = CURLE_OK;
79   struct Curl_easy *data = conn->data;
80   curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
81   char *gopherpath;
82   char *path = data->state.up.path;
83   char *query = data->state.up.query;
84   char *sel = NULL;
85   char *sel_org = NULL;
86   ssize_t amount, k;
87   size_t len;
88 
89   *done = TRUE; /* unconditionally */
90 
91   /* path is guaranteed non-NULL */
92   DEBUGASSERT(path);
93 
94   if(query)
95     gopherpath = aprintf("%s?%s", path, query);
96   else
97     gopherpath = strdup(path);
98 
99   if(!gopherpath)
100     return CURLE_OUT_OF_MEMORY;
101 
102   /* Create selector. Degenerate cases: / and /1 => convert to "" */
103   if(strlen(gopherpath) <= 2) {
104     sel = (char *)"";
105     len = strlen(sel);
106     free(gopherpath);
107   }
108   else {
109     char *newp;
110 
111     /* Otherwise, drop / and the first character (i.e., item type) ... */
112     newp = gopherpath;
113     newp += 2;
114 
115     /* ... and finally unescape */
116     result = Curl_urldecode(data, newp, 0, &sel, &len, FALSE);
117     free(gopherpath);
118     if(result)
119       return result;
120     sel_org = sel;
121   }
122 
123   /* We use Curl_write instead of Curl_sendf to make sure the entire buffer is
124      sent, which could be sizeable with long selectors. */
125   k = curlx_uztosz(len);
126 
127   for(;;) {
128     result = Curl_write(conn, sockfd, sel, k, &amount);
129     if(!result) { /* Which may not have written it all! */
130       result = Curl_client_write(conn, CLIENTWRITE_HEADER, sel, amount);
131       if(result)
132         break;
133 
134       k -= amount;
135       sel += amount;
136       if(k < 1)
137         break; /* but it did write it all */
138     }
139     else
140       break;
141 
142     /* Don't busyloop. The entire loop thing is a work-around as it causes a
143        BLOCKING behavior which is a NO-NO. This function should rather be
144        split up in a do and a doing piece where the pieces that aren't
145        possible to send now will be sent in the doing function repeatedly
146        until the entire request is sent.
147 
148        Wait a while for the socket to be writable. Note that this doesn't
149        acknowledge the timeout.
150     */
151     if(SOCKET_WRITABLE(sockfd, 100) < 0) {
152       result = CURLE_SEND_ERROR;
153       break;
154     }
155   }
156 
157   free(sel_org);
158 
159   if(!result)
160     /* We can use Curl_sendf to send the terminal \r\n relatively safely and
161        save allocing another string/doing another _write loop. */
162     result = Curl_sendf(sockfd, conn, "\r\n");
163   if(result) {
164     failf(data, "Failed sending Gopher request");
165     return result;
166   }
167   result = Curl_client_write(conn, CLIENTWRITE_HEADER, (char *)"\r\n", 2);
168   if(result)
169     return result;
170 
171   Curl_setup_transfer(data, FIRSTSOCKET, -1, FALSE, -1);
172   return CURLE_OK;
173 }
174 #endif /*CURL_DISABLE_GOPHER*/
175