diff --git a/chansession.h b/chansession.h index 213c285..4513b1a 100644 --- a/chansession.h +++ b/chansession.h @@ -78,6 +78,9 @@ void addnewvar(const char* param, const char* var); void cli_send_chansess_request(); void cli_tty_cleanup(); void cli_chansess_winchange(); +#ifdef ENABLE_CLI_NETCAT +void cli_send_netcat_request(); +#endif void svr_chansessinitialise(); extern const struct ChanType svrchansess; diff --git a/cli-chansession.c b/cli-chansession.c index c92f902..07b9b9d 100644 --- a/cli-chansession.c +++ b/cli-chansession.c @@ -338,9 +338,8 @@ static void send_chansess_shell_req(struct Channel *channel) { TRACE(("leave send_chansess_shell_req")) } -static int cli_initchansess(struct Channel *channel) { - - +/* Shared for normal client channel and netcat-alike */ +static int cli_init_stdpipe_sess(struct Channel *channel) { channel->writefd = STDOUT_FILENO; setnonblocking(STDOUT_FILENO); @@ -351,6 +350,12 @@ static int cli_initchansess(struct Channel *channel) { setnonblocking(STDERR_FILENO); channel->extrabuf = cbuf_new(opts.recv_window); + return 0; +} + +static int cli_initchansess(struct Channel *channel) { + + cli_init_stdpipe_sess(channel); if (cli_opts.wantpty) { send_chansess_pty_req(channel); @@ -363,12 +368,48 @@ static int cli_initchansess(struct Channel *channel) { } return 0; /* Success */ - } +#ifdef ENABLE_CLI_NETCAT + +void cli_send_netcat_request() { + + const unsigned char* source_host = "127.0.0.1"; + const int source_port = 22; + + const struct ChanType cli_chan_netcat = { + 0, /* sepfds */ + "direct-tcpip", + cli_init_stdpipe_sess, /* inithandler */ + NULL, + NULL, + cli_closechansess + }; + + cli_opts.wantpty = 0; + + if (send_msg_channel_open_init(STDIN_FILENO, &cli_chan_netcat) + == DROPBEAR_FAILURE) { + dropbear_exit("Couldn't open initial channel"); + } + + buf_putstring(ses.writepayload, cli_opts.netcat_host, + strlen(cli_opts.netcat_host)); + buf_putint(ses.writepayload, cli_opts.netcat_port); + + /* originator ip - localhost is accurate enough */ + buf_putstring(ses.writepayload, source_host, strlen(source_host)); + buf_putint(ses.writepayload, source_port); + + encrypt_packet(); + TRACE(("leave cli_send_chansess_request")) +} +#endif + void cli_send_chansess_request() { TRACE(("enter cli_send_chansess_request")) + if (send_msg_channel_open_init(STDIN_FILENO, &clichansess) == DROPBEAR_FAILURE) { dropbear_exit("Couldn't open initial channel"); @@ -379,3 +420,16 @@ void cli_send_chansess_request() { TRACE(("leave cli_send_chansess_request")) } + + +#if 0 + while (cli_opts.localfwds != NULL) { + ret = cli_localtcp(cli_opts.localfwds->listenport, + cli_opts.localfwds->connectaddr, + cli_opts.localfwds->connectport); + if (ret == DROPBEAR_FAILURE) { + dropbear_log(LOG_WARNING, "Failed local port forward %d:%s:%d", + cli_opts.localfwds->listenport, + cli_opts.localfwds->connectaddr, + cli_opts.localfwds->connectport); +#endif diff --git a/cli-runopts.c b/cli-runopts.c index 611723c..b97f12e 100644 --- a/cli-runopts.c +++ b/cli-runopts.c @@ -33,13 +33,16 @@ cli_runopts cli_opts; /* GLOBAL */ static void printhelp(); -static void parsehostname(char* userhostarg); +static void parsehostname(const char* orighostarg); static void fill_own_user(); #ifdef ENABLE_CLI_PUBKEY_AUTH static void loadidentityfile(const char* filename); #endif #ifdef ENABLE_CLI_ANYTCPFWD -static void addforward(char* str, struct TCPFwdList** fwdlist); +static void addforward(const char* str, struct TCPFwdList** fwdlist); +#endif +#ifdef ENABLE_CLI_NETCAT +static void add_netcat(const char *str); #endif static void printhelp() { @@ -66,6 +69,9 @@ static void printhelp() { #endif "-W <receive_window_buffer> (default %d, larger may be faster, max 1MB)\n" "-K <keepalive> (0 is never, default %d)\n" +#ifdef ENABLE_CLI_NETCAT + "-B <endhost:endport> Netcat-alike bouncing\n" +#endif #ifdef ENABLE_CLI_PROXYCMD "-J <proxy_program> Use program rather than tcp connection\n" #endif @@ -90,6 +96,9 @@ void cli_getopts(int argc, char ** argv) { #endif #ifdef ENABLE_CLI_REMOTETCPFWD int nextisremote = 0; +#endif +#ifdef ENABLE_CLI_NETCAT + int nextisnetcat = 0; #endif char* dummy = NULL; /* Not used for anything real */ @@ -152,6 +161,14 @@ void cli_getopts(int argc, char ** argv) { nextislocal = 0; continue; } +#endif +#ifdef ENABLE_CLI_NETCAT + if (nextisnetcat) { + TRACE(("nextisnetcat true")) + add_netcat(argv[i]); + nextisnetcat = 0; + continue; + } #endif if (next) { /* The previous flag set a value to assign */ @@ -208,6 +225,11 @@ void cli_getopts(int argc, char ** argv) { nextisremote = 1; break; #endif +#ifdef ENABLE_CLI_NETCAT + case 'B': + nextisnetcat = 1; + break; +#endif #ifdef ENABLE_CLI_PROXYCMD case 'J': next = &cli_opts.proxycmd; @@ -362,12 +384,13 @@ static void loadidentityfile(const char* filename) { #endif -/* Parses a [user@]hostname argument. userhostarg is the argv[i] corresponding - * - note that it will be modified */ -static void parsehostname(char* orighostarg) { +/* Parses a [user@]hostname argument. orighostarg is the argv[i] corresponding */ +static void parsehostname(const char* orighostarg) { + + uid_t uid; + struct passwd *pw = NULL; char *userhostarg = NULL; - /* We probably don't want to be editing argvs */ userhostarg = m_strdup(orighostarg); cli_opts.remotehost = strchr(userhostarg, '@'); @@ -390,6 +413,44 @@ static void parsehostname(char* orighostarg) { } } +#ifdef ENABLE_CLI_NETCAT +static void add_netcat(const char* origstr) { + char *portstr = NULL; + + char * str = m_strdup(origstr); + + portstr = strchr(str, ':'); + if (portstr == NULL) { + TRACE(("No netcat port")) + goto fail; + } + *portstr = '\0'; + portstr++; + + if (strchr(portstr, ':')) { + TRACE(("Multiple netcat colons")) + goto fail; + } + + cli_opts.netcat_port = strtoul(portstr, NULL, 10); + if (errno != 0) { + TRACE(("bad netcat port")) + goto fail; + } + + if (cli_opts.netcat_port > 65535) { + TRACE(("too large netcat port")) + goto fail; + } + + cli_opts.netcat_host = str; + return; + +fail: + dropbear_exit("Bad netcat endpoint '%s'", origstr); +} +#endif + static void fill_own_user() { uid_t uid; struct passwd *pw = NULL; @@ -407,7 +468,7 @@ static void fill_own_user() { #ifdef ENABLE_CLI_ANYTCPFWD /* Turn a "listenport:remoteaddr:remoteport" string into into a forwarding * set, and add it to the forwarding list */ -static void addforward(char* origstr, struct TCPFwdList** fwdlist) { +static void addforward(const char* origstr, struct TCPFwdList** fwdlist) { char * listenport = NULL; char * connectport = NULL; @@ -443,13 +504,13 @@ static void addforward(char* origstr, struct TCPFwdList** fwdlist) { /* Now we check the ports - note that the port ints are unsigned, * the check later only checks for >= MAX_PORT */ - newfwd->listenport = strtol(listenport, NULL, 10); + newfwd->listenport = strtoul(listenport, NULL, 10); if (errno != 0) { TRACE(("bad listenport strtol")) goto fail; } - newfwd->connectport = strtol(connectport, NULL, 10); + newfwd->connectport = strtoul(connectport, NULL, 10); if (errno != 0) { TRACE(("bad connectport strtol")) goto fail; diff --git a/cli-session.c b/cli-session.c index 3d9ce98..d0a7361 100644 --- a/cli-session.c +++ b/cli-session.c @@ -197,20 +197,6 @@ static void cli_sessionloop() { TRACE(("leave cli_sessionloop: cli_auth_try")) return; - /* - case USERAUTH_SUCCESS_RCVD: - send_msg_service_request(SSH_SERVICE_CONNECTION); - cli_ses.state = SERVICE_CONN_REQ_SENT; - TRACE(("leave cli_sessionloop: sent ssh-connection service req")) - return; - - case SERVICE_CONN_ACCEPT_RCVD: - cli_send_chansess_request(); - TRACE(("leave cli_sessionloop: cli_send_chansess_request")) - cli_ses.state = SESSION_RUNNING; - return; - */ - case USERAUTH_SUCCESS_RCVD: if (cli_opts.backgrounded) { @@ -235,7 +221,13 @@ static void cli_sessionloop() { #ifdef ENABLE_CLI_REMOTETCPFWD setup_remotetcp(); #endif - if (!cli_opts.no_cmd) { + +#ifdef ENABLE_CLI_NETCAT + if (cli_opts.netcat_host) { + cli_send_netcat_request(); + } else +#endif + if (!cli_opts.no_cmd) { cli_send_chansess_request(); } TRACE(("leave cli_sessionloop: running")) diff --git a/options.h b/options.h index 54cfc65..f393c54 100644 --- a/options.h +++ b/options.h @@ -70,6 +70,10 @@ etc) slower (perhaps by 50%). Recommended for most small systems. */ /* Enable Authentication Agent Forwarding - server only for now */ #define ENABLE_AGENTFWD +/* Enable "Netcat mode". TODO describe here. */ +#define ENABLE_CLI_NETCAT + + /* Encryption - at least one required. * RFC Draft requires 3DES and recommends AES128 for interoperability. * Including multiple keysize variants the same cipher diff --git a/runopts.h b/runopts.h index 4ec7534..1be82a6 100644 --- a/runopts.h +++ b/runopts.h @@ -118,6 +118,11 @@ typedef struct cli_runopts { #ifdef ENABLE_CLI_LOCALTCPFWD struct TCPFwdList * localfwds; #endif + +#ifdef ENABLE_CLI_NETCAT + char *netcat_host; + unsigned int netcat_port; +#endif #ifdef ENABLE_CLI_PROXYCMD char *proxycmd; #endif