int buflen;
};
-static int pfd_closing(Plug plug, char *error_msg, int error_code,
+static int pfd_closing(Plug plug, const char *error_msg, int error_code,
int calling_back)
{
struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
if (pr->dynamic) {
while (len--) {
+ /*
+ * Throughout SOCKS negotiation, "hostname" is re-used as a
+ * random protocol buffer with "port" storing the length.
+ */
if (pr->port >= lenof(pr->hostname)) {
+ /* Request too long. */
if ((pr->dynamic >> 12) == 4) {
/* Send back a SOCKS 4 error before closing. */
char data[8];
pr->dynamic = 0x4000;
if (pr->port < 2) continue;/* don't have command code yet */
if (pr->hostname[1] != 1) {
+ /* Not CONNECT. */
/* Send back a SOCKS 4 error before closing. */
char data[8];
memset(data, 0, sizeof(data));
pfd_close(pr->s);
return 1;
}
- if (pr->port < 8) continue; /* haven't started username */
+ if (pr->port <= 8) continue; /* haven't started user/hostname */
if (pr->hostname[pr->port-1] != 0)
- continue; /* haven't _finished_ username */
+ continue; /* haven't _finished_ user/hostname */
/*
* Now we have a full SOCKS 4 request. Check it to
* see if it's a SOCKS 4A request.
pr->hostname[0] = 0; /* reply version code */
pr->hostname[1] = 90; /* request granted */
sk_write(pr->s, pr->hostname, 8);
- len= pr->port;
+ len= pr->port - 8;
pr->port = GET_16BIT_MSB_FIRST(pr->hostname+2);
memmove(pr->hostname, pr->hostname + 8, len);
goto connect;
}
if (pr->dynamic == 0x5001) {
- int atype, alen;
+ /*
+ * We're receiving a SOCKS request.
+ */
+ unsigned char reply[10]; /* SOCKS5 atyp=1 reply */
+ int atype, alen = 0;
+
+ /*
+ * Pre-fill reply packet.
+ * In all cases, we set BND.{HOST,ADDR} to 0.0.0.0:0
+ * (atyp=1) in the reply; if we succeed, we don't know
+ * the right answers, and if we fail, they should be
+ * ignored.
+ */
+ memset(reply, 0, lenof(reply));
+ reply[0] = 5; /* VER */
+ reply[3] = 1; /* ATYP = 1 (IPv4, 0.0.0.0:0) */
+
if (pr->port < 6) continue;
atype = (unsigned char)pr->hostname[3];
if (atype == 1) /* IPv4 address */
alen = 1 + (unsigned char)pr->hostname[4];
if (pr->port < 6 + alen) continue;
if (pr->hostname[1] != 1 || pr->hostname[2] != 0) {
- pr->hostname[1] = 1; /* generic failure */
- pr->hostname[2] = 0; /* reserved */
- sk_write(pr->s, pr->hostname, pr->port);
+ /* Not CONNECT or reserved field nonzero - error */
+ reply[1] = 1; /* generic failure */
+ sk_write(pr->s, reply, lenof(reply));
pfd_close(pr->s);
return 1;
}
*/
pr->port = GET_16BIT_MSB_FIRST(pr->hostname+4+alen);
if (atype == 1) {
- pr->hostname[1] = 0; /* succeeded */
- sk_write(pr->s, pr->hostname, alen + 6);
+ /* REP=0 (success) already */
+ sk_write(pr->s, reply, lenof(reply));
sprintf(pr->hostname, "%d.%d.%d.%d",
(unsigned char)pr->hostname[4],
(unsigned char)pr->hostname[5],
(unsigned char)pr->hostname[7]);
goto connect;
} else if (atype == 3) {
- pr->hostname[1] = 0; /* succeeded */
- sk_write(pr->s, pr->hostname, alen + 6);
+ /* REP=0 (success) already */
+ sk_write(pr->s, reply, lenof(reply));
memmove(pr->hostname, pr->hostname + 5, alen-1);
pr->hostname[alen-1] = '\0';
goto connect;
/*
* Unknown address type. (FIXME: support IPv6!)
*/
- pr->hostname[1] = 8; /* atype not supported */
- sk_write(pr->s, pr->hostname, pr->port);
+ reply[1] = 8; /* atype not supported */
+ sk_write(pr->s, reply, lenof(reply));
pfd_close(pr->s);
return 1;
}
/*
* Called when receiving a PORT OPEN from the server
*/
-char *pfd_newconnect(Socket *s, char *hostname, int port, void *c,
- const Config *cfg)
+const char *pfd_newconnect(Socket *s, char *hostname, int port,
+ void *c, const Config *cfg)
{
static const struct plug_function_table fn_table = {
pfd_closing,
};
SockAddr addr;
- char *err, *dummy_realhost;
+ const char *err;
+ char *dummy_realhost;
struct PFwdPrivate *pr;
/*
* Try to find host.
*/
addr = name_lookup(hostname, port, &dummy_realhost, cfg);
- if ((err = sk_addr_error(addr)) != NULL)
+ if ((err = sk_addr_error(addr)) != NULL) {
+ sk_addr_free(addr);
return err;
+ }
/*
* Open socket.
}
sk_set_private_ptr(*s, pr);
- sk_addr_free(addr);
return NULL;
}
called when someone connects to the local port
*/
-static int pfd_accepting(Plug p, void *sock)
+static int pfd_accepting(Plug p, OSSocket sock)
{
static const struct plug_function_table fn_table = {
pfd_closing,
};
struct PFwdPrivate *pr, *org;
Socket s;
- char *err;
+ const char *err;
org = (struct PFwdPrivate *)p;
pr = snew(struct PFwdPrivate);
if (org->dynamic) {
pr->dynamic = 1;
- pr->port = 0; /* hostname buffer is so far empty */
+ pr->port = 0; /* "hostname" buffer is so far empty */
sk_set_frozen(s, 0); /* we want to receive SOCKS _now_! */
} else {
pr->dynamic = 0;
/* Add a new forwarding from port -> desthost:destport
sets up a listener on the local machine on (srcaddr:)port
*/
-char *pfd_addforward(char *desthost, int destport, char *srcaddr, int port,
- void *backhandle, const Config *cfg)
+const char *pfd_addforward(char *desthost, int destport, char *srcaddr,
+ int port, void *backhandle, const Config *cfg)
{
static const struct plug_function_table fn_table = {
pfd_closing,
pfd_accepting
};
- char *err;
+ const char *err;
struct PFwdPrivate *pr;
Socket s;