1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24 /* <DESC>
25 * Pass in a custom socket for libcurl to use.
26 * </DESC>
27 */
28 #ifdef _WIN32
29 #ifndef _WINSOCK_DEPRECATED_NO_WARNINGS
30 #define _WINSOCK_DEPRECATED_NO_WARNINGS /* for inet_addr() */
31 #endif
32 #endif
33
34 #include <stdio.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #include <curl/curl.h>
38
39 #ifdef _WIN32
40 #define close closesocket
41 #else
42 #include <sys/types.h> /* socket types */
43 #include <sys/socket.h> /* socket definitions */
44 #include <netinet/in.h>
45 #include <arpa/inet.h> /* inet (3) functions */
46 #include <unistd.h> /* misc. Unix functions */
47 #endif
48
49 #include <errno.h>
50
51 /* The IP address and port number to connect to */
52 #define IPADDR "127.0.0.1"
53 #define PORTNUM 80
54
55 #ifndef INADDR_NONE
56 #define INADDR_NONE 0xffffffff
57 #endif
58
write_data(void * ptr,size_t size,size_t nmemb,void * stream)59 static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
60 {
61 size_t written = fwrite(ptr, size, nmemb, (FILE *)stream);
62 return written;
63 }
64
closecb(void * clientp,curl_socket_t item)65 static int closecb(void *clientp, curl_socket_t item)
66 {
67 (void)clientp;
68 printf("libcurl wants to close %d now\n", (int)item);
69 return 0;
70 }
71
opensocket(void * clientp,curlsocktype purpose,struct curl_sockaddr * address)72 static curl_socket_t opensocket(void *clientp,
73 curlsocktype purpose,
74 struct curl_sockaddr *address)
75 {
76 curl_socket_t sockfd;
77 (void)purpose;
78 (void)address;
79 sockfd = *(curl_socket_t *)clientp;
80 /* the actual externally set socket is passed in via the OPENSOCKETDATA
81 option */
82 return sockfd;
83 }
84
sockopt_callback(void * clientp,curl_socket_t curlfd,curlsocktype purpose)85 static int sockopt_callback(void *clientp, curl_socket_t curlfd,
86 curlsocktype purpose)
87 {
88 (void)clientp;
89 (void)curlfd;
90 (void)purpose;
91 /* This return code was added in libcurl 7.21.5 */
92 return CURL_SOCKOPT_ALREADY_CONNECTED;
93 }
94
main(void)95 int main(void)
96 {
97 CURL *curl;
98 CURLcode res;
99 struct sockaddr_in servaddr; /* socket address structure */
100 curl_socket_t sockfd;
101
102 #ifdef _WIN32
103 WSADATA wsaData;
104 int initwsa = WSAStartup(MAKEWORD(2, 2), &wsaData);
105 if(initwsa) {
106 printf("WSAStartup failed: %d\n", initwsa);
107 return 1;
108 }
109 #endif
110
111 curl = curl_easy_init();
112 if(curl) {
113 /*
114 * Note that libcurl internally thinks that you connect to the host and
115 * port that you specify in the URL option.
116 */
117 curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
118
119 /* Create the socket "manually" */
120 sockfd = socket(AF_INET, SOCK_STREAM, 0);
121 if(sockfd == CURL_SOCKET_BAD) {
122 printf("Error creating listening socket.\n");
123 return 3;
124 }
125
126 memset(&servaddr, 0, sizeof(servaddr));
127 servaddr.sin_family = AF_INET;
128 servaddr.sin_port = htons(PORTNUM);
129
130 servaddr.sin_addr.s_addr = inet_addr(IPADDR);
131 if(INADDR_NONE == servaddr.sin_addr.s_addr) {
132 close(sockfd);
133 return 2;
134 }
135
136 if(connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) ==
137 -1) {
138 close(sockfd);
139 printf("client error: connect: %s\n", strerror(errno));
140 return 1;
141 }
142
143 /* no progress meter please */
144 curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L);
145
146 /* send all data to this function */
147 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
148
149 /* call this function to get a socket */
150 curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
151 curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);
152
153 /* call this function to close sockets */
154 curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closecb);
155 curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &sockfd);
156
157 /* call this function to set options for the socket */
158 curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
159
160 curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
161
162 res = curl_easy_perform(curl);
163
164 curl_easy_cleanup(curl);
165
166 close(sockfd);
167
168 if(res) {
169 printf("libcurl error: %d\n", res);
170 return 4;
171 }
172 }
173
174 #ifdef _WIN32
175 WSACleanup();
176 #endif
177 return 0;
178 }
179
