/* Create a new channel, and start the open request. This is intended
* for X11, agent, tcp forwarding, and should be filled with channel-specific
* options, with the calling function calling encrypt_packet() after
* completion. It is mandatory for the caller to encrypt_packet() if
* DROPBEAR_SUCCESS is returned */
int send_msg_channel_open_init(int fd, const char * typestring) {
struct Channel* chan;
chan = newchannel(0, CHANNEL_ID_AGENT, 0, 0);
if (!chan) {
return DROPBEAR_FAILURE;
}
/* set fd non-blocking */
if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
return DROPBEAR_FAILURE;
}
chan->infd = chan->outfd = fd;
ses.maxfd = MAX(ses.maxfd, fd);
/* now open the channel connection */
CHECKCLEARTOWRITE();
buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_OPEN);
buf_putstring(ses.writepayload, typestring, strlen(typestring));
buf_putint(ses.writepayload, chan->index);
buf_putint(ses.writepayload, RECV_MAXWINDOW);
buf_putint(ses.writepayload, RECV_MAXPACKET);
return DROPBEAR_SUCCESS;
}
static void
listenloop(char *listfile, int ctlfd, char *buf, int size)
{
int fd, n;
while ((fd = open(listfile, ORDWR)) >= 0) {
n = read(fd, buf, size - 1);
fprint(errfd, "read from listen file returned %d\n", n);
if (n <= 0) {
syslog(0, "ssh", "read on listen failed: %r");
break;
}
buf[n >= 0? n: 0] = '\0';
fprint(errfd, "read %s\n", buf);
switch (fork()) {
case 0: /* child */
close(ctlfd);
newchannel(fd, netdir, atoi(buf)); /* never returns */
case -1:
syslog(0, "ssh", "fork failed: %r");
hangup(ctlfd);
exits("fork");
}
close(fd);
}
if (fd < 0)
syslog(0, "ssh", "listen failed: %r");
}
/* Handle a new channel request, performing any channel-type-specific setup */
void recv_msg_channel_open() {
unsigned char* type;
unsigned int typelen;
unsigned int typeval;
unsigned int remotechan, transwindow, transmaxpacket;
struct Channel* channel;
unsigned int errtype = SSH_OPEN_UNKNOWN_CHANNEL_TYPE;
TRACE(("enter recv_msg_channel_open"));
/* get the packet contents */
type = buf_getstring(ses.payload, &typelen);
remotechan = buf_getint(ses.payload);
transwindow = buf_getint(ses.payload);
transwindow = MIN(transwindow, MAX_TRANS_WINDOW);
transmaxpacket = buf_getint(ses.payload);
transmaxpacket = MIN(transmaxpacket, MAX_TRANS_PAYLOAD_LEN);
/* figure what type of packet it is */
if (typelen > MAX_NAME_LEN) {
goto failure;
}
if (strcmp(type, "session") == 0) {
typeval = CHANNEL_ID_SESSION;
#ifndef DISABLE_LOCALTCPFWD
} else if (strcmp(type, "direct-tcpip") == 0) {
typeval = CHANNEL_ID_TCPDIRECT;
#endif
} else {
goto failure;
}
/* create the channel */
channel = newchannel(remotechan, typeval, transwindow, transmaxpacket);
if (channel == NULL) {
errtype = SSH_OPEN_RESOURCE_SHORTAGE;
goto failure;
}
/* type specific initialisation */
if (typeval == CHANNEL_ID_SESSION) {
newchansess(channel);
#ifndef DISABLE_LOCALTCPFWD
} else if (typeval == CHANNEL_ID_TCPDIRECT) {
if (newtcpdirect(channel) == DROPBEAR_FAILURE) {
deletechannel(channel);
goto failure;
}
#endif
}
/* success */
send_msg_channel_open_confirmation(channel, channel->recvwindow,
channel->recvmaxpacket);
goto cleanup;
failure:
send_msg_channel_open_failure(remotechan, errtype, "", "");
cleanup:
m_free(type);
TRACE(("leave recv_msg_channel_open"));
}
