/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at https://curl.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ***************************************************************************/ /* <DESC> * An example demonstrating how an application can pass in a custom * socket to libcurl to use. This example also handles the connect itself. * </DESC> */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <curl/curl.h> #ifdef WIN32 #include <windows.h> #include <winsock2.h> #include <ws2tcpip.h> #define close closesocket #else #include <sys/types.h> /* socket types */ #include <sys/socket.h> /* socket definitions */ #include <netinet/in.h> #include <arpa/inet.h> /* inet (3) functions */ #include <unistd.h> /* misc. Unix functions */ #endif #include <errno.h> /* The IP address and port number to connect to */ #define IPADDR "127.0.0.1" #define PORTNUM 80 #ifndef INADDR_NONE #define INADDR_NONE 0xffffffff #endif static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream) { size_t written = fwrite(ptr, size, nmemb, (FILE *)stream); return written; } static int closecb(void *clientp, curl_socket_t item) { (void)clientp; printf("libcurl wants to close %d now\n", (int)item); return 0; } static curl_socket_t opensocket(void *clientp, curlsocktype purpose, struct curl_sockaddr *address) { curl_socket_t sockfd; (void)purpose; (void)address; sockfd = *(curl_socket_t *)clientp; /* the actual externally set socket is passed in via the OPENSOCKETDATA option */ return sockfd; } static int sockopt_callback(void *clientp, curl_socket_t curlfd, curlsocktype purpose) { (void)clientp; (void)curlfd; (void)purpose; /* This return code was added in libcurl 7.21.5 */ return CURL_SOCKOPT_ALREADY_CONNECTED; } int main(void) { CURL *curl; CURLcode res; struct sockaddr_in servaddr; /* socket address structure */ curl_socket_t sockfd; #ifdef WIN32 WSADATA wsaData; int initwsa = WSAStartup(MAKEWORD(2, 0), &wsaData); if(initwsa != 0) { printf("WSAStartup failed: %d\n", initwsa); return 1; } #endif curl = curl_easy_init(); if(curl) { /* * Note that libcurl will internally think that you connect to the host * and port that you specify in the URL option. */ curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999"); /* Create the socket "manually" */ sockfd = socket(AF_INET, SOCK_STREAM, 0); if(sockfd == CURL_SOCKET_BAD) { printf("Error creating listening socket.\n"); return 3; } memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(PORTNUM); servaddr.sin_addr.s_addr = inet_addr(IPADDR); if(INADDR_NONE == servaddr.sin_addr.s_addr) { close(sockfd); return 2; } if(connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) == -1) { close(sockfd); printf("client error: connect: %s\n", strerror(errno)); return 1; } /* no progress meter please */ curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L); /* send all data to this function */ curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data); /* call this function to get a socket */ curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket); curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd); /* call this function to close sockets */ curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closecb); curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &sockfd); /* call this function to set options for the socket */ curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback); curl_easy_setopt(curl, CURLOPT_VERBOSE, 1); res = curl_easy_perform(curl); curl_easy_cleanup(curl); close(sockfd); if(res) { printf("libcurl error: %d\n", res); return 4; } } #ifdef WIN32 WSACleanup(); #endif return 0; }