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authormarha <marha@users.sourceforge.net>2014-04-15 00:06:14 +0200
committermarha <marha@users.sourceforge.net>2014-04-15 00:06:14 +0200
commitdda1497a1e88c6cb8b8d91a7bc61283b697e8ea0 (patch)
treefb2bc84af03d9482335bfe21e4b25f68c63327f9 /tools/plink/winhsock.c
parentc7a23c91d421c37cc2893f6f52a1dceb0c3e9f85 (diff)
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Added plink noterm.c winhsock.c
Diffstat (limited to 'tools/plink/winhsock.c')
-rw-r--r--tools/plink/winhsock.c267
1 files changed, 267 insertions, 0 deletions
diff --git a/tools/plink/winhsock.c b/tools/plink/winhsock.c
new file mode 100644
index 000000000..6d7e7da4f
--- /dev/null
+++ b/tools/plink/winhsock.c
@@ -0,0 +1,267 @@
+/*
+ * General mechanism for wrapping up reading/writing of Windows
+ * HANDLEs into a PuTTY Socket abstraction.
+ */
+
+#include <stdio.h>
+#include <assert.h>
+#include <limits.h>
+
+#define DEFINE_PLUG_METHOD_MACROS
+#include "tree234.h"
+#include "putty.h"
+#include "network.h"
+
+typedef struct Socket_handle_tag *Handle_Socket;
+
+struct Socket_handle_tag {
+ const struct socket_function_table *fn;
+ /* the above variable absolutely *must* be the first in this structure */
+
+ HANDLE send_H, recv_H;
+ struct handle *send_h, *recv_h;
+
+ /*
+ * Freezing one of these sockets is a slightly fiddly business,
+ * because the reads from the handle are happening in a separate
+ * thread as blocking system calls and so once one is in progress
+ * it can't sensibly be interrupted. Hence, after the user tries
+ * to freeze one of these sockets, it's unavoidable that we may
+ * receive one more load of data before we manage to get
+ * winhandl.c to stop reading.
+ */
+ enum {
+ UNFROZEN, /* reading as normal */
+ FREEZING, /* have been set to frozen but winhandl is still reading */
+ FROZEN, /* really frozen - winhandl has been throttled */
+ THAWING /* we're gradually releasing our remaining data */
+ } frozen;
+ /* We buffer data here if we receive it from winhandl while frozen. */
+ bufchain inputdata;
+
+ char *error;
+
+ Plug plug;
+};
+
+static int handle_gotdata(struct handle *h, void *data, int len)
+{
+ Handle_Socket ps = (Handle_Socket) handle_get_privdata(h);
+
+ if (len < 0) {
+ return plug_closing(ps->plug, "Read error from handle",
+ 0, 0);
+ } else if (len == 0) {
+ return plug_closing(ps->plug, NULL, 0, 0);
+ } else {
+ assert(ps->frozen != FREEZING && ps->frozen != THAWING);
+ if (ps->frozen == FREEZING) {
+ /*
+ * If we've received data while this socket is supposed to
+ * be frozen (because the read winhandl.c started before
+ * sk_set_frozen was called has now returned) then buffer
+ * the data for when we unfreeze.
+ */
+ bufchain_add(&ps->inputdata, data, len);
+
+ /*
+ * And return a very large backlog, to prevent further
+ * data arriving from winhandl until we unfreeze.
+ */
+ return INT_MAX;
+ } else {
+ return plug_receive(ps->plug, 0, data, len);
+ }
+ }
+}
+
+static void handle_sentdata(struct handle *h, int new_backlog)
+{
+ Handle_Socket ps = (Handle_Socket) handle_get_privdata(h);
+
+ plug_sent(ps->plug, new_backlog);
+}
+
+static Plug sk_handle_plug(Socket s, Plug p)
+{
+ Handle_Socket ps = (Handle_Socket) s;
+ Plug ret = ps->plug;
+ if (p)
+ ps->plug = p;
+ return ret;
+}
+
+static void sk_handle_close(Socket s)
+{
+ Handle_Socket ps = (Handle_Socket) s;
+
+ handle_free(ps->send_h);
+ handle_free(ps->recv_h);
+ CloseHandle(ps->send_H);
+ if (ps->recv_H != ps->send_H)
+ CloseHandle(ps->recv_H);
+ bufchain_clear(&ps->inputdata);
+
+ sfree(ps);
+}
+
+static int sk_handle_write(Socket s, const char *data, int len)
+{
+ Handle_Socket ps = (Handle_Socket) s;
+
+ return handle_write(ps->send_h, data, len);
+}
+
+static int sk_handle_write_oob(Socket s, const char *data, int len)
+{
+ /*
+ * oob data is treated as inband; nasty, but nothing really
+ * better we can do
+ */
+ return sk_handle_write(s, data, len);
+}
+
+static void sk_handle_write_eof(Socket s)
+{
+ Handle_Socket ps = (Handle_Socket) s;
+
+ handle_write_eof(ps->send_h);
+}
+
+static void sk_handle_flush(Socket s)
+{
+ /* Handle_Socket ps = (Handle_Socket) s; */
+ /* do nothing */
+}
+
+static void handle_socket_unfreeze(void *psv)
+{
+ Handle_Socket ps = (Handle_Socket) psv;
+ void *data;
+ int len, new_backlog;
+
+ /*
+ * If we've been put into a state other than THAWING since the
+ * last callback, then we're done.
+ */
+ if (ps->frozen != THAWING)
+ return;
+
+ /*
+ * Get some of the data we've buffered.
+ */
+ bufchain_prefix(&ps->inputdata, &data, &len);
+ assert(len > 0);
+
+ /*
+ * Hand it off to the plug.
+ */
+ new_backlog = plug_receive(ps->plug, 0, data, len);
+
+ if (bufchain_size(&ps->inputdata) > 0) {
+ /*
+ * If there's still data in our buffer, stay in THAWING state,
+ * and reschedule ourself.
+ */
+ queue_toplevel_callback(handle_socket_unfreeze, ps);
+ } else {
+ /*
+ * Otherwise, we've successfully thawed!
+ */
+ ps->frozen = UNFROZEN;
+ handle_unthrottle(ps->recv_h, new_backlog);
+ }
+}
+
+static void sk_handle_set_frozen(Socket s, int is_frozen)
+{
+ Handle_Socket ps = (Handle_Socket) s;
+
+ if (is_frozen) {
+ switch (ps->frozen) {
+ case FREEZING:
+ case FROZEN:
+ return; /* nothing to do */
+
+ case THAWING:
+ /*
+ * We were in the middle of emptying our bufchain, and got
+ * frozen again. In that case, winhandl.c is already
+ * throttled, so just return to FROZEN state. The toplevel
+ * callback will notice and disable itself.
+ */
+ ps->frozen = FROZEN;
+ break;
+
+ case UNFROZEN:
+ /*
+ * The normal case. Go to FREEZING, and expect one more
+ * load of data from winhandl if we're unlucky.
+ */
+ ps->frozen = FREEZING;
+ break;
+ }
+ } else {
+ switch (ps->frozen) {
+ case UNFROZEN:
+ case THAWING:
+ return; /* nothing to do */
+
+ case FREEZING:
+ /*
+ * If winhandl didn't send us any data throughout the time
+ * we were frozen, then we'll still be in this state and
+ * can just unfreeze in the trivial way.
+ */
+ assert(bufchain_size(&ps->inputdata) == 0);
+ ps->frozen = UNFROZEN;
+ break;
+
+ case FROZEN:
+ /*
+ * If we have buffered data, go to THAWING and start
+ * releasing it in top-level callbacks.
+ */
+ ps->frozen = THAWING;
+ queue_toplevel_callback(handle_socket_unfreeze, ps);
+ }
+ }
+}
+
+static const char *sk_handle_socket_error(Socket s)
+{
+ Handle_Socket ps = (Handle_Socket) s;
+ return ps->error;
+}
+
+Socket make_handle_socket(HANDLE send_H, HANDLE recv_H, Plug plug,
+ int overlapped)
+{
+ static const struct socket_function_table socket_fn_table = {
+ sk_handle_plug,
+ sk_handle_close,
+ sk_handle_write,
+ sk_handle_write_oob,
+ sk_handle_write_eof,
+ sk_handle_flush,
+ sk_handle_set_frozen,
+ sk_handle_socket_error
+ };
+
+ Handle_Socket ret;
+ int flags = (overlapped ? HANDLE_FLAG_OVERLAPPED : 0);
+
+ ret = snew(struct Socket_handle_tag);
+ ret->fn = &socket_fn_table;
+ ret->plug = plug;
+ ret->error = NULL;
+ ret->frozen = UNFROZEN;
+ bufchain_init(&ret->inputdata);
+
+ ret->recv_H = recv_H;
+ ret->recv_h = handle_input_new(ret->recv_H, handle_gotdata, ret, flags);
+ ret->send_H = send_H;
+ ret->send_h = handle_output_new(ret->send_H, handle_sentdata, ret, flags);
+
+ return (Socket) ret;
+}