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 #include <stdio.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <curl/curl.h>
32
33 #ifdef WIN32
34 #include <windows.h>
35 #include <winsock2.h>
36 #include <ws2tcpip.h>
37 #define close closesocket
38 #else
39 #include <sys/types.h> /* socket types */
40 #include <sys/socket.h> /* socket definitions */
41 #include <netinet/in.h>
42 #include <arpa/inet.h> /* inet (3) functions */
43 #include <unistd.h> /* misc. Unix functions */
44 #endif
45
46 #include <errno.h>
47
48 /* The IP address and port number to connect to */
49 #define IPADDR "127.0.0.1"
50 #define PORTNUM 80
51
52 #ifndef INADDR_NONE
53 #define INADDR_NONE 0xffffffff
54 #endif
55
write_data(void * ptr,size_t size,size_t nmemb,void * stream)56 static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
57 {
58 size_t written = fwrite(ptr, size, nmemb, (FILE *)stream);
59 return written;
60 }
61
closecb(void * clientp,curl_socket_t item)62 static int closecb(void *clientp, curl_socket_t item)
63 {
64 (void)clientp;
65 printf("libcurl wants to close %d now\n", (int)item);
66 return 0;
67 }
68
opensocket(void * clientp,curlsocktype purpose,struct curl_sockaddr * address)69 static curl_socket_t opensocket(void *clientp,
70 curlsocktype purpose,
71 struct curl_sockaddr *address)
72 {
73 curl_socket_t sockfd;
74 (void)purpose;
75 (void)address;
76 sockfd = *(curl_socket_t *)clientp;
77 /* the actual externally set socket is passed in via the OPENSOCKETDATA
78 option */
79 return sockfd;
80 }
81
sockopt_callback(void * clientp,curl_socket_t curlfd,curlsocktype purpose)82 static int sockopt_callback(void *clientp, curl_socket_t curlfd,
83 curlsocktype purpose)
84 {
85 (void)clientp;
86 (void)curlfd;
87 (void)purpose;
88 /* This return code was added in libcurl 7.21.5 */
89 return CURL_SOCKOPT_ALREADY_CONNECTED;
90 }
91
main(void)92 int main(void)
93 {
94 CURL *curl;
95 CURLcode res;
96 struct sockaddr_in servaddr; /* socket address structure */
97 curl_socket_t sockfd;
98
99 #ifdef WIN32
100 WSADATA wsaData;
101 int initwsa = WSAStartup(MAKEWORD(2, 2), &wsaData);
102 if(initwsa) {
103 printf("WSAStartup failed: %d\n", initwsa);
104 return 1;
105 }
106 #endif
107
108 curl = curl_easy_init();
109 if(curl) {
110 /*
111 * Note that libcurl will internally think that you connect to the host
112 * and port that you specify in the URL option.
113 */
114 curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
115
116 /* Create the socket "manually" */
117 sockfd = socket(AF_INET, SOCK_STREAM, 0);
118 if(sockfd == CURL_SOCKET_BAD) {
119 printf("Error creating listening socket.\n");
120 return 3;
121 }
122
123 memset(&servaddr, 0, sizeof(servaddr));
124 servaddr.sin_family = AF_INET;
125 servaddr.sin_port = htons(PORTNUM);
126
127 servaddr.sin_addr.s_addr = inet_addr(IPADDR);
128 if(INADDR_NONE == servaddr.sin_addr.s_addr) {
129 close(sockfd);
130 return 2;
131 }
132
133 if(connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) ==
134 -1) {
135 close(sockfd);
136 printf("client error: connect: %s\n", strerror(errno));
137 return 1;
138 }
139
140 /* no progress meter please */
141 curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L);
142
143 /* send all data to this function */
144 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
145
146 /* call this function to get a socket */
147 curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
148 curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);
149
150 /* call this function to close sockets */
151 curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closecb);
152 curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &sockfd);
153
154 /* call this function to set options for the socket */
155 curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
156
157 curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
158
159 res = curl_easy_perform(curl);
160
161 curl_easy_cleanup(curl);
162
163 close(sockfd);
164
165 if(res) {
166 printf("libcurl error: %d\n", res);
167 return 4;
168 }
169 }
170
171 #ifdef WIN32
172 WSACleanup();
173 #endif
174 return 0;
175 }
176