144 lines
3.7 KiB
C
144 lines
3.7 KiB
C
/*
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splice.c -- Splice two outgoing tinc connections together
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Copyright (C) 2018 Guus Sliepen <guus@tinc-vpn.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <stdio.h>
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#include <stdbool.h>
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#include <string.h>
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#include <errno.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netdb.h>
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#ifdef HAVE_MINGW
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extern const char *winerror(int);
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#define strerror(x) ((x)>0?strerror(x):winerror(GetLastError()))
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#define sockerrno WSAGetLastError()
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#define sockstrerror(x) winerror(x)
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#else
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#define sockerrno errno
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#define sockstrerror(x) strerror(x)
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#endif
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int main(int argc, char *argv[]) {
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if(argc < 7) {
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fprintf(stderr, "Usage: %s name1 host1 port1 name2 host2 port2 [protocol]\n", argv[0]);
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return 1;
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}
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const char *protocol;
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if(argc >= 8) {
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protocol = argv[7];
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} else {
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protocol = "17.7";
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}
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#ifdef HAVE_MINGW
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static struct WSAData wsa_state;
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if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
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return 1;
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}
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#endif
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int sock[2];
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char buf[1024];
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struct addrinfo *ai, hint;
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memset(&hint, 0, sizeof(hint));
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hint.ai_family = AF_UNSPEC;
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hint.ai_socktype = SOCK_STREAM;
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hint.ai_protocol = IPPROTO_TCP;
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hint.ai_flags = 0;
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for (int i = 0; i < 2; i++) {
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if(getaddrinfo(argv[2 + 3 * i], argv[3 + 3 * i], &hint, &ai) || !ai) {
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fprintf(stderr, "getaddrinfo() failed: %s\n", sockstrerror(sockerrno));
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return 1;
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}
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sock[i] = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
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if(sock[i] == -1) {
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fprintf(stderr, "Could not create socket: %s\n", sockstrerror(sockerrno));
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return 1;
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}
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if(connect(sock[i], ai->ai_addr, ai->ai_addrlen)) {
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fprintf(stderr, "Could not connect to %s: %s\n", argv[i + 3 * i], sockstrerror(sockerrno));
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return 1;
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}
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fprintf(stderr, "Connected to %s\n", argv[1 + 3 * i]);
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/* Pretend to be the other one */
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int len = snprintf(buf, sizeof buf, "0 %s %s\n", argv[4 - 3 * i], protocol);
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if (send(sock[i], buf, len, 0) != len) {
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fprintf(stderr, "Error sending data to %s: %s\n", argv[1 + 3 * i], sockstrerror(sockerrno));
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return 1;
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}
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/* Ignore the response */
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do {
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if (recv(sock[i], buf, 1, 0) != 1) {
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fprintf(stderr, "Error reading data from %s: %s\n", argv[1 + 3 * i], sockstrerror(sockerrno));
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return 1;
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}
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} while(*buf != '\n');
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}
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fprintf(stderr, "Splicing...\n");
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int nfds = (sock[0] > sock[1] ? sock[0] : sock[1]) + 1;
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while(true) {
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fd_set fds;
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FD_ZERO(&fds);
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FD_SET(sock[0], &fds);
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FD_SET(sock[1], &fds);
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if(select(nfds, &fds, NULL, NULL, NULL) <= 0) {
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return 1;
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}
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for(int i = 0; i < 2; i++ ) {
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if(FD_ISSET(sock[i], &fds)) {
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ssize_t len = recv(sock[i], buf, sizeof buf, 0);
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if(len < 0) {
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fprintf(stderr, "Error while reading from %s: %s\n", argv[1 + i * 3], sockstrerror(sockerrno));
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return 1;
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}
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if(len == 0) {
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fprintf(stderr, "Connection closed by %s\n", argv[1 + i * 3]);
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return 0;
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}
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if(send(sock[i ^ 1], buf, len, 0) != len) {
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fprintf(stderr, "Error while writing to %s: %s\n", argv[4 - i * 3], sockstrerror(sockerrno));
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return 1;
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}
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}
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}
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}
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return 0;
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}
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