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obstcp-cli.c
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obstcp-cli.c
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// Copyright 2008, Google Inc.
// All rights reserved.
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "libobstcp.h"
static const char quit_on_stdin_eof = 0;
static int
client(uint32_t destip, const char *advert) {
const int urfd = open("/dev/urandom", O_RDONLY);
if (urfd < 0) {
perror("opening urandom");
return 1;
}
struct obstcp_keys keys;
obstcp_keys_init(&keys);
uint8_t private_key[32];
if (read(urfd, private_key, sizeof(private_key)) != sizeof(private_key)) {
perror("reading from /dev/urandom");
return 1;
}
if (!obstcp_keys_key_add(&keys, private_key)) {
perror("obstcp_keys_key_add");
return 1;
}
uint8_t randbytes[16];
if (read(urfd, randbytes, sizeof(randbytes)) != sizeof(randbytes)) {
perror("reading from /dev/urandom");
return 1;
}
struct obstcp_client_ctx ctx;
if (!obstcp_client_ctx_init(&ctx, &keys, advert, strlen(advert), randbytes)) {
perror("obstcp_client_ctx_init");
return 1;
}
int port;
if (!obstcp_advert_base32_parse(advert, strlen(advert),
OBSTCP_ADVERT_OBSPORT, &port,
OBSTCP_ADVERT_END)) {
perror("obstcp_advert_parse");
return 1;
}
const int fd = socket(PF_INET, SOCK_STREAM, 0);
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = htons(port);
sin.sin_addr.s_addr = destip;
if (connect(fd, (struct sockaddr *) &sin, sizeof(sin))) {
perror("connect");
return 1;
}
struct iovec iov[3];
obstcp_client_banner(&ctx, &iov[0]);
write(fd, iov[0].iov_base, iov[0].iov_len);
const int efd = epoll_create(2);
if (efd < 0) {
perror("epoll_create");
return 1;
}
struct epoll_event eev;
memset(&eev, 0, sizeof(eev));
eev.events = EPOLLIN;
eev.data.fd = 0;
if (epoll_ctl(efd, EPOLL_CTL_ADD, 0, &eev)) {
perror("epoll_ctl");
return 1;
}
eev.data.fd = fd;
if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &eev)) {
perror("epoll_ctl");
return 1;
}
struct obstcp_rbuf rbuf;
obstcp_rbuf_client_init(&rbuf, &ctx);
for (;;) {
if (epoll_wait(efd, &eev, 1, -1) == -1) {
perror("epoll_wait");
return 1;
}
if (eev.data.fd == 0) {
uint8_t buffer[8192];
ssize_t n;
do {
n = read(0, buffer, sizeof(buffer));
} while (n == -1 && errno == EINTR);
if (n == 0) {
fprintf(stderr, " ** Stdin closed\n");
if (quit_on_stdin_eof)
return 0;
epoll_ctl(efd, EPOLL_CTL_DEL, 0, NULL);
} else if (n < 0) {
perror("reading from stdin");
return 1;
} else {
struct iovec iov[2];
obstcp_client_encrypt(&ctx, buffer, buffer, n);
const int a = obstcp_client_prefix(&ctx, &iov[0]);
if (a == -1) {
perror("obstcp_server_ends");
return 1;
} else if (a == 0) {
write(fd, buffer, n);
} else {
iov[1].iov_base = buffer;
iov[1].iov_len = n;
writev(fd, iov, 2);
}
}
} else {
uint8_t buffer[8192];
const ssize_t n =
obstcp_rbuf_read_fd(&rbuf, fd, buffer, sizeof(buffer));
if (n == 0) {
fprintf(stderr, " ** Remote closed\n");
return 0;
} else if (n < 0) {
perror("obstcp_rbuf_read_fd");
return 1;
} else {
write(1, buffer, n);
}
}
}
}
static int
usage(const char *argv0) {
fprintf(stderr, "Usage: %s <destination ip> <server advert>\n", argv0);
return 1;
}
int
main(int argc, char **argv) {
if (argc != 3) return usage(argv[0]);
struct in_addr inaddr;
if (inet_aton(argv[1], &inaddr) == 0) return usage(argv[0]);
return client(inaddr.s_addr, argv[2]);
}