libssh2-tunnel/forward-tunnel.c

457 lines
13 KiB
C

#include "forward-tunnel.h"
const char *keyfile1 = "/home/aixiao/.ssh/id_rsa.pub";
const char *keyfile2 = "/home/aixiao/.ssh/id_rsa";
char *server_ssh_ip = "47.108.253.59";
int server_ssh_port = 22;
char *server_ssh_user = "root";
char *server_ssh_passwd = "123456";
const char *local_listenip = "0.0.0.0";
unsigned int local_listenport = 3009;
char *remote_desthost = "0.0.0.0"; /* resolved by the server */
unsigned int remote_destport = 3306;
enum {
AUTH_NONE = 0,
AUTH_PASSWORD,
AUTH_PUBLICKEY
};
void *forward_tunnel(void *p)
{
int forwardsock = *(int *)p;
int rc, i, auth = AUTH_NONE;
struct sockaddr_in sin;
const char *fingerprint;
char *userauthlist;
LIBSSH2_SESSION *session;
LIBSSH2_CHANNEL *channel = NULL;
const char *shost;
unsigned int sport;
fd_set fds;
struct timeval tv;
ssize_t len, wr;
char buffer[16384];
int sock;
bzero(buffer, 0);
rc = libssh2_init(0);
if (rc) {
fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
return NULL;
}
/* Connect to SSH server */
sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sock == -1) {
perror("socket");
return NULL;
}
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = inet_addr(server_ssh_ip);
if (INADDR_NONE == sin.sin_addr.s_addr) {
perror("inet_addr");
return NULL;
}
sin.sin_port = htons(server_ssh_port);
if (connect(sock, (struct sockaddr *)(&sin), sizeof(struct sockaddr_in)) != 0) {
fprintf(stderr, "failed to connect!\n");
return NULL;
}
/* Create a session instance */
session = libssh2_session_init();
if (!session) {
fprintf(stderr, "Could not initialize SSH session!\n");
return NULL;
}
/* ... start it up. This will trade welcome banners, exchange keys,
* and setup crypto, compression, and MAC layers
*/
rc = libssh2_session_handshake(session, sock);
if (rc) {
fprintf(stderr, "Error when starting up SSH session: %d\n", rc);
return NULL;
}
/* At this point we havn't yet authenticated. The first thing to do
* is check the hostkey's fingerprint against our known hosts Your app
* may have it hard coded, may go to a file, may present it to the
* user, that's your call
*/
fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
fprintf(stderr, "Fingerprint: ");
for (i = 0; i < 20; i++)
fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
fprintf(stderr, "\n");
/* check what authentication methods are available */
userauthlist = libssh2_userauth_list(session, server_ssh_user, strlen(server_ssh_user));
fprintf(stderr, "Authentication methods: %s\n", userauthlist);
if (strstr(userauthlist, "password"))
auth |= AUTH_PASSWORD;
if (strstr(userauthlist, "publickey"))
auth |= AUTH_PUBLICKEY;
if (auth & AUTH_PASSWORD) {
if (libssh2_userauth_password(session, server_ssh_user, server_ssh_passwd)) {
fprintf(stderr, "Authentication by password failed.\n");
goto shutdown;
}
} else if (auth & AUTH_PUBLICKEY) {
if (libssh2_userauth_publickey_fromfile(session, server_ssh_user, keyfile1, keyfile2, server_ssh_passwd)) {
fprintf(stderr, "\tAuthentication by public key failed!\n");
goto shutdown;
}
fprintf(stderr, "\tAuthentication by public key succeeded.\n");
} else {
fprintf(stderr, "No supported authentication methods found!\n");
goto shutdown;
}
shost = inet_ntoa(sin.sin_addr);
sport = ntohs(sin.sin_port);
fprintf(stderr, "Forwarding connection from %s:%d here to remote %s:%d\n", shost, sport, remote_desthost, remote_destport);
channel = libssh2_channel_direct_tcpip_ex(session, remote_desthost, remote_destport, shost, sport);
if (!channel) {
fprintf(stderr, "Could not open the direct-tcpip channel!\n" "(Note that this can be a problem at the server!" " Please review the server logs.)\n");
goto shutdown;
}
/* Setting session to non-blocking IO */
libssh2_session_set_blocking(session, 0);
while (1) {
FD_ZERO(&fds);
FD_SET(forwardsock, &fds); // 设置一个描述符
tv.tv_sec = 0;
tv.tv_usec = 100000;
rc = select(forwardsock + 1, &fds, NULL, NULL, &tv);
if (-1 == rc) { // 返回-1表示出错
perror("select");
goto shutdown;
}
if (rc && FD_ISSET(forwardsock, &fds)) { // 测试某一个描述符返回值: 若fd在描述符集中则返回非0,否则返回0
len = read(forwardsock, buffer, sizeof(buffer));
if (len < 0) {
perror("read");
goto shutdown;
} else if (0 == len) {
fprintf(stderr, "The client at %s:%d disconnected!\n", shost, sport);
goto shutdown;
}
wr = 0;
while (wr < len) {
i = libssh2_channel_write(channel, buffer + wr, len - wr);
if (LIBSSH2_ERROR_EAGAIN == i) {
continue;
}
if (i < 0) {
fprintf(stderr, "libssh2_channel_write: %d\n", i);
goto shutdown;
}
wr += i;
}
}
while (1) {
len = libssh2_channel_read(channel, buffer, sizeof(buffer));
if (LIBSSH2_ERROR_EAGAIN == len)
break;
else if (len < 0) {
fprintf(stderr, "libssh2_channel_read: %d", (int)len);
goto shutdown;
}
wr = 0;
while (wr < len) {
i = write(forwardsock, buffer + wr, len - wr);
if (i <= 0) {
perror("write");
goto shutdown;
}
wr += i;
}
if (libssh2_channel_eof(channel)) {
fprintf(stderr, "The server at %s:%d disconnected!\n", remote_desthost, remote_destport);
goto shutdown;
}
}
}
shutdown:
close(forwardsock);
if (channel)
libssh2_channel_free(channel);
libssh2_session_set_blocking(session, 1);
libssh2_session_disconnect(session, "Client disconnecting normally");
libssh2_session_free(session);
close(sock);
libssh2_exit();
return NULL;
}
static char help_info(void)
{
static const char name[] = "STunnel";
static const char subject[] = "SSH forward tunnel";
static const struct {
const char *email;
const char *version;
} author = {
"AIXIAO@AIXIAO.ME",
"1.0",
};
static const char usage[] = "Usage: [-d] [-rsplueh?]";
static const char *s_help[] = {
"",
"Options:",
" -d : Background running",
" -r : SSH Server IP",
" -p : SSH Server Port (default: 22)",
" -u : SSH Server User",
" -e : SSH Server User Passwd",
" -s : Remote Dest Port (default: 3306 1521)",
" -l : Local_Listen Port",
" -? -h : help information",
"",
"",
0
};
fprintf(stderr, " %s %s\n", name, subject);
fprintf(stderr, "Author: %s\n", author.email);
fprintf(stderr, "Version: %s\n", author.version);
fprintf(stderr, "%s\n", usage);
int l;
for (l = 0; s_help[l]; l++) {
fprintf(stderr, "%s\n", s_help[l]);
}
BUILD("Compile、link.\n");
puts("");
return 0;
}
int nice( int increment)
{
int oldprio = getpriority(PRIO_PROCESS, getpid());
printf("%d\n", oldprio);
return setpriority(PRIO_PROCESS, getpid(), oldprio + increment);
}
int main(int argc, char *argv[], char **env)
{
struct sockaddr_in sin;
struct sockaddr_in server_addr;
socklen_t server_addr_len;
int sockopt = 1;
int listensock = -1, forwardsock = -1;
int daemon_ = 0;
int opt;
char *p = NULL;
char optstring[] = ":dr:s:p:l:u:e:h?";
while (-1 != (opt = getopt(argc, argv, optstring))) {
switch (opt) {
case 'd':
daemon_ = 1;
break;
case 'r':
server_ssh_ip = strdup(optarg);
break;
case 's':
p = strchr(optarg, ':');
if (p != NULL) {
remote_destport = atoi(p + 1);
*p = '\0';
remote_desthost = optarg;
} else {
if (NULL == (p = strchr(optarg, '.')))
{
remote_destport =atoi(optarg);
remote_desthost = "0.0.0.0";
} else {
help_info();
exit(0);
}
}
break;
case 'p':
server_ssh_port = atoi(optarg);
break;
case 'l':
local_listenport = atoi(optarg);
break;
case 'u':
server_ssh_user = strdup(optarg);
break;
case 'e':
server_ssh_passwd = strdup(optarg);;
break;
case 'h':
case '?':
help_info();
exit(0);
break;
default:
;
}
}
int i, j;
for (i = 1; i < argc; i++) {
if (0 == strcmp(argv[i], "-e") || 0 == strcmp(argv[i], "-u") || 0 == strcmp(argv[i], "-p"))
{
for (j = strlen(argv[i+1]) - 1; j >= 0; j--) {
argv[i+1][j] = 'x';
}
}
}
printf("SSH Server: %s:%d, Local listen: %s:%d, User&Passwd: [%s]['%s']\n", server_ssh_ip, remote_destport, local_listenip, local_listenport, server_ssh_user, server_ssh_passwd);
listensock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (listensock == -1) {
perror("socket");
return -1;
}
sin.sin_family = AF_INET;
sin.sin_port = htons(local_listenport);
sin.sin_addr.s_addr = inet_addr(local_listenip);
if (INADDR_NONE == sin.sin_addr.s_addr) {
perror("inet_addr");
goto shutdown;
}
if (setsockopt(listensock, SOL_SOCKET, SO_REUSEADDR, &sockopt, sizeof(sockopt)) < 0) {
perror("setsockopt");
return -1;
}
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(local_listenport);
server_addr.sin_addr.s_addr = INADDR_ANY;
if (bind(listensock, (struct sockaddr *)&server_addr, sizeof(server_addr)) != 0) {
perror("bind");
goto shutdown;
}
if (listen(listensock, 500) < 0) {
perror("listen");
goto shutdown;
}
fprintf(stderr, "Waiting for TCP connection on %s:%d...\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
if (daemon_ == 1) {
if (daemon(1, 1)) {
perror("daemon");
return -1;
}
}
if (-1 == (nice(-20))) // 进程优先级
perror("nice");
pthread_t thread_id = 0;
pthread_attr_t attr;
struct sched_param param;
sigset_t signal_mask;
sigemptyset(&signal_mask);
sigaddset(&signal_mask, SIGPIPE); // 忽略PIPE信号
if (pthread_sigmask(SIG_BLOCK, &signal_mask, NULL) != 0) {
printf("block sigpipe error\n");
}
// 初始化线程属性
pthread_attr_init(&attr);
// 设置线程调度策略为SCHED_FIFO
pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
// 设置线程优先级为50
param.sched_priority = 50;
pthread_attr_setschedparam(&attr, &param);
while (1) {
server_addr_len = sizeof(server_addr);
forwardsock = accept(listensock, (struct sockaddr *)&sin, &server_addr_len);
if (forwardsock == -1) {
perror("accept");
goto shutdown;
}
getsockname(forwardsock, (struct sockaddr *)&sin, &server_addr_len);
char *ip = inet_ntoa(sin.sin_addr);
printf("Client IP address: %s\n", ip);
pthread_create(&thread_id, &attr, &forward_tunnel, (void *)&forwardsock);
}
pthread_attr_destroy(&attr);
pthread_join(thread_id, NULL);
pthread_exit(NULL);
shutdown:
close(forwardsock);
close(listensock);
libssh2_exit();
if (server_ssh_ip)
free(server_ssh_ip);
if (server_ssh_user)
free(server_ssh_user);
if (server_ssh_passwd)
free(server_ssh_passwd);
return 0;
}