/*
sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
accept()
*/
static bool juggle(curl_socket_t *sockfdp,
curl_socket_t listenfd,
enum sockmode *mode)
{
struct timeval timeout;
fd_set fds_read;
fd_set fds_write;
fd_set fds_err;
curl_socket_t sockfd = CURL_SOCKET_BAD;
int maxfd = -99;
ssize_t rc;
ssize_t nread_socket;
ssize_t bytes_written;
ssize_t buffer_len;
int error = 0;
/* 'buffer' is this excessively large only to be able to support things like
test 1003 which tests exceedingly large server response lines */
unsigned char buffer[17010];
char data[16];
if(got_exit_signal) {
logmsg("signalled to die, exiting...");
return FALSE;
}
#ifdef HAVE_GETPPID
/* As a last resort, quit if sockfilt process becomes orphan. Just in case
parent ftpserver process has died without killing its sockfilt children */
if(getppid() <= 1) {
logmsg("process becomes orphan, exiting");
return FALSE;
}
#endif
timeout.tv_sec = 120;
timeout.tv_usec = 0;
FD_ZERO(&fds_read);
FD_ZERO(&fds_write);
FD_ZERO(&fds_err);
FD_SET((curl_socket_t)fileno(stdin), &fds_read);
switch(*mode) {
case PASSIVE_LISTEN:
/* server mode */
sockfd = listenfd;
/* there's always a socket to wait for */
FD_SET(sockfd, &fds_read);
maxfd = (int)sockfd;
break;
case PASSIVE_CONNECT:
sockfd = *sockfdp;
if(CURL_SOCKET_BAD == sockfd) {
/* eeek, we are supposedly connected and then this cannot be -1 ! */
logmsg("socket is -1! on %s:%d", __FILE__, __LINE__);
maxfd = 0; /* stdin */
}
else {
/* there's always a socket to wait for */
FD_SET(sockfd, &fds_read);
#ifdef USE_WINSOCK
FD_SET(sockfd, &fds_err);
#endif
maxfd = (int)sockfd;
}
break;
case ACTIVE:
sockfd = *sockfdp;
/* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
if(CURL_SOCKET_BAD != sockfd) {
FD_SET(sockfd, &fds_read);
#ifdef USE_WINSOCK
FD_SET(sockfd, &fds_err);
#endif
maxfd = (int)sockfd;
}
else {
logmsg("No socket to read on");
maxfd = 0;
}
break;
case ACTIVE_DISCONNECT:
logmsg("disconnected, no socket to read on");
maxfd = 0;
sockfd = CURL_SOCKET_BAD;
break;
} /* switch(*mode) */
do {
/* select() blocking behavior call on blocking descriptors please */
rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
if(got_exit_signal) {
logmsg("signalled to die, exiting...");
return FALSE;
}
} while((rc == -1) && ((error = errno) == EINTR));
if(rc < 0) {
logmsg("select() failed with error: (%d) %s",
error, strerror(error));
return FALSE;
}
if(rc == 0)
/* timeout */
return TRUE;
if(FD_ISSET(fileno(stdin), &fds_read)) {
/* read from stdin, commands/data to be dealt with and possibly passed on
to the socket
protocol:
4 letter command + LF [mandatory]
4-digit hexadecimal data length + LF [if the command takes data]
data [the data being as long as set above]
Commands:
DATA - plain pass-thru data
*/
if(!read_stdin(buffer, 5))
return FALSE;
logmsg("Received %c%c%c%c (on stdin)",
buffer[0], buffer[1], buffer[2], buffer[3] );
if(!memcmp("PING", buffer, 4)) {
/* send reply on stdout, just proving we are alive */
if(!write_stdout("PONG\n", 5))
return FALSE;
}
else if(!memcmp("PORT", buffer, 4)) {
/* Question asking us what PORT number we are listening to.
Replies to PORT with "IPv[num]/[port]" */
sprintf((char *)buffer, "%s/%hu\n", ipv_inuse, port);
buffer_len = (ssize_t)strlen((char *)buffer);
snprintf(data, sizeof(data), "PORT\n%04zx\n", buffer_len);
if(!write_stdout(data, 10))
return FALSE;
if(!write_stdout(buffer, buffer_len))
return FALSE;
}
else if(!memcmp("QUIT", buffer, 4)) {
/* just die */
logmsg("quits");
return FALSE;
}
else if(!memcmp("DATA", buffer, 4)) {
/* data IN => data OUT */
if(!read_stdin(buffer, 5))
return FALSE;
buffer[5] = '\0';
buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16);
if (buffer_len > (ssize_t)sizeof(buffer)) {
logmsg("ERROR: Buffer size (%zu bytes) too small for data size "
"(%zd bytes)", sizeof(buffer), buffer_len);
return FALSE;
}
logmsg("> %zd bytes data, server => client", buffer_len);
if(!read_stdin(buffer, buffer_len))
return FALSE;
lograw(buffer, buffer_len);
if(*mode == PASSIVE_LISTEN) {
logmsg("*** We are disconnected!");
if(!write_stdout("DISC\n", 5))
return FALSE;
}
else {
/* send away on the socket */
bytes_written = swrite(sockfd, buffer, buffer_len);
if(bytes_written != buffer_len) {
logmsg("Not all data was sent. Bytes to send: %zd sent: %zd",
buffer_len, bytes_written);
}
}
}
else if(!memcmp("DISC", buffer, 4)) {
/* disconnect! */
if(!write_stdout("DISC\n", 5))
return FALSE;
if(sockfd != CURL_SOCKET_BAD) {
logmsg("====> Client forcibly disconnected");
sclose(sockfd);
*sockfdp = CURL_SOCKET_BAD;
if(*mode == PASSIVE_CONNECT)
*mode = PASSIVE_LISTEN;
else
*mode = ACTIVE_DISCONNECT;
}
else
logmsg("attempt to close already dead connection");
return TRUE;
}
}
if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
curl_socket_t newfd = CURL_SOCKET_BAD; /* newly accepted socket */
if(*mode == PASSIVE_LISTEN) {
/* there's no stream set up yet, this is an indication that there's a
client connecting. */
newfd = accept(sockfd, NULL, NULL);
if(CURL_SOCKET_BAD == newfd) {
error = SOCKERRNO;
logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
sockfd, error, strerror(error));
}
else {
logmsg("====> Client connect");
if(!write_stdout("CNCT\n", 5))
return FALSE;
*sockfdp = newfd; /* store the new socket */
*mode = PASSIVE_CONNECT; /* we have connected */
}
return TRUE;
}
/* read from socket, pass on data to stdout */
nread_socket = sread(sockfd, buffer, sizeof(buffer));
if(nread_socket > 0) {
snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket);
if(!write_stdout(data, 10))
return FALSE;
if(!write_stdout(buffer, nread_socket))
return FALSE;
logmsg("< %zd bytes data, client => server", nread_socket);
lograw(buffer, nread_socket);
}
if(nread_socket <= 0
#ifdef USE_WINSOCK
|| FD_ISSET(sockfd, &fds_err)
#endif
) {
logmsg("====> Client disconnect");
if(!write_stdout("DISC\n", 5))
return FALSE;
sclose(sockfd);
*sockfdp = CURL_SOCKET_BAD;
if(*mode == PASSIVE_CONNECT)
*mode = PASSIVE_LISTEN;
else
*mode = ACTIVE_DISCONNECT;
return TRUE;
}
}
return TRUE;
}
/*
sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
accept()
*/
static int juggle(curl_socket_t *sockfdp,
curl_socket_t listenfd,
enum sockmode *mode)
{
struct timeval timeout;
fd_set fds_read;
fd_set fds_write;
fd_set fds_err;
curl_socket_t sockfd;
curl_socket_t maxfd;
ssize_t rc;
ssize_t nread_stdin;
ssize_t nread_socket;
ssize_t bytes_written;
ssize_t buffer_len;
unsigned char buffer[256]; /* FIX: bigger buffer */
char data[256];
timeout.tv_sec = 120;
timeout.tv_usec = 0;
FD_ZERO(&fds_read);
FD_ZERO(&fds_write);
FD_ZERO(&fds_err);
FD_SET(fileno(stdin), &fds_read);
switch(*mode) {
case PASSIVE_LISTEN:
/* server mode */
sockfd = listenfd;
/* there's always a socket to wait for */
FD_SET(sockfd, &fds_read);
maxfd = sockfd;
break;
case PASSIVE_CONNECT:
sockfd = *sockfdp;
if(CURL_SOCKET_BAD == sockfd) {
/* eeek, we are supposedly connected and then this cannot be -1 ! */
logmsg("socket is -1! on %s:%d", __FILE__, __LINE__);
maxfd = 0; /* stdin */
}
else {
/* there's always a socket to wait for */
FD_SET(sockfd, &fds_read);
maxfd = sockfd;
}
break;
case ACTIVE:
sockfd = *sockfdp;
/* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
if(CURL_SOCKET_BAD != sockfd) {
FD_SET(sockfd, &fds_read);
maxfd = sockfd;
}
else {
logmsg("No socket to read on");
maxfd = 0;
}
break;
case ACTIVE_DISCONNECT:
logmsg("disconnected, no socket to read on");
maxfd = 0;
sockfd = CURL_SOCKET_BAD;
break;
} /* switch(*mode) */
do {
rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
} while((rc == -1) && (SOCKERRNO == EINTR));
switch(rc) {
case -1:
return FALSE;
case 0: /* timeout! */
return TRUE;
}
if(FD_ISSET(fileno(stdin), &fds_read)) {
/* read from stdin, commands/data to be dealt with and possibly passed on
to the socket
protocol:
4 letter command + LF [mandatory]
4-digit hexadecimal data length + LF [if the command takes data]
data [the data being as long as set above]
Commands:
DATA - plain pass-thru data
*/
nread_stdin = read(fileno(stdin), buffer, 5);
if(5 == nread_stdin) {
logmsg("Received %c%c%c%c (on stdin)",
buffer[0], buffer[1], buffer[2], buffer[3] );
if(!memcmp("PING", buffer, 4)) {
/* send reply on stdout, just proving we are alive */
write(fileno(stdout), "PONG\n", 5);
}
else if(!memcmp("PORT", buffer, 4)) {
/* Question asking us what PORT number we are listening to.
Replies to PORT with "IPv[num]/[port]" */
sprintf((char *)buffer, "IPv%d/%d\n", use_ipv6?6:4, (int)port);
buffer_len = (ssize_t)strlen((char *)buffer);
sprintf(data, "PORT\n%04x\n", buffer_len);
write(fileno(stdout), data, 10);
write(fileno(stdout), buffer, buffer_len);
}
else if(!memcmp("QUIT", buffer, 4)) {
/* just die */
logmsg("quits");
return FALSE;
}
else if(!memcmp("DATA", buffer, 4)) {
/* data IN => data OUT */
if(5 != read(fileno(stdin), buffer, 5))
return FALSE;
buffer[5] = '\0';
buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16);
if (buffer_len > (ssize_t)sizeof(buffer)) {
logmsg("Buffer size %d too small for data size %d",
(int)sizeof(buffer), buffer_len);
return FALSE;
}
nread_stdin = read(fileno(stdin), buffer, buffer_len);
if(nread_stdin != buffer_len)
return FALSE;
logmsg("> %d bytes data, server => client", buffer_len);
lograw(buffer, buffer_len);
if(*mode == PASSIVE_LISTEN) {
logmsg("*** We are disconnected!");
write(fileno(stdout), "DISC\n", 5);
}
else {
/* send away on the socket */
bytes_written = swrite(sockfd, buffer, buffer_len);
if(bytes_written != buffer_len) {
logmsg("Not all data was sent. Bytes to send: %d sent: %d",
buffer_len, bytes_written);
}
}
}
else if(!memcmp("DISC", buffer, 4)) {
/* disconnect! */
write(fileno(stdout), "DISC\n", 5);
if(sockfd != CURL_SOCKET_BAD) {
logmsg("====> Client forcibly disconnected");
sclose(sockfd);
*sockfdp = CURL_SOCKET_BAD;
if(*mode == PASSIVE_CONNECT)
*mode = PASSIVE_LISTEN;
else
*mode = ACTIVE_DISCONNECT;
}
else
logmsg("attempt to close already dead connection");
return TRUE;
}
}
else if(-1 == nread_stdin) {
logmsg("read %d from stdin, exiting", nread_stdin);
return FALSE;
}
}
if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
if(*mode == PASSIVE_LISTEN) {
/* there's no stream set up yet, this is an indication that there's a
client connecting. */
sockfd = accept(sockfd, NULL, NULL);
if(CURL_SOCKET_BAD == sockfd)
logmsg("accept() failed");
else {
logmsg("====> Client connect");
write(fileno(stdout), "CNCT\n", 5);
*sockfdp = sockfd; /* store the new socket */
*mode = PASSIVE_CONNECT; /* we have connected */
}
return TRUE;
}
/* read from socket, pass on data to stdout */
nread_socket = sread(sockfd, buffer, sizeof(buffer));
if(nread_socket <= 0) {
logmsg("====> Client disconnect");
write(fileno(stdout), "DISC\n", 5);
sclose(sockfd);
*sockfdp = CURL_SOCKET_BAD;
if(*mode == PASSIVE_CONNECT)
*mode = PASSIVE_LISTEN;
else
*mode = ACTIVE_DISCONNECT;
return TRUE;
}
sprintf(data, "DATA\n%04x\n", nread_socket);
write(fileno(stdout), data, 10);
write(fileno(stdout), buffer, nread_socket);
logmsg("< %d bytes data, client => server", nread_socket);
lograw(buffer, nread_socket);
}
return TRUE;
}
