1 files changed, 113 insertions, 0 deletions
diff --git a/windows/sharing.c b/windows/sharing.c
new file mode 100644
index 00000000..15b1da48
--- /dev/null
+++ b/windows/sharing.c
@@ -0,0 +1,113 @@
+/*
+ * Windows implementation of SSH connection-sharing IPC setup.
+ */
+
+#include <stdio.h>
+#include <assert.h>
+
+#include "tree234.h"
+#include "putty.h"
+#include "network.h"
+#include "proxy/proxy.h"
+#include "ssh.h"
+
+#include "cryptoapi.h"
+#include "security-api.h"
+
+#define CONNSHARE_PIPE_PREFIX "\\\\.\\pipe\\putty-connshare"
+#define CONNSHARE_MUTEX_PREFIX "Local\\putty-connshare-mutex"
+
+static char *make_name(const char *prefix, const char *name)
+{
+    char *username, *retname;
+
+    username = get_username();
+    retname = dupprintf("%s.%s.%s", prefix, username, name);
+    sfree(username);
+
+    return retname;
+}
+
+int platform_ssh_share(const char *pi_name, Conf *conf,
+                       Plug *downplug, Plug *upplug, Socket **sock,
+                       char **logtext, char **ds_err, char **us_err,
+                       bool can_upstream, bool can_downstream)
+{
+    char *name, *mutexname, *pipename;
+    HANDLE mutex;
+    Socket *retsock;
+
+    /*
+     * Transform the platform-independent version of the connection
+     * identifier into the obfuscated version we'll use for our
+     * Windows named pipe and mutex. A side effect of doing this is
+     * that it also eliminates any characters illegal in Windows pipe
+     * names.
+     */
+    name = capi_obfuscate_string(pi_name);
+    if (!name) {
+        *logtext = dupprintf("Unable to call CryptProtectMemory: %s",
+                             win_strerror(GetLastError()));
+        return SHARE_NONE;
+    }
+
+    /*
+     * Make a mutex name out of the connection identifier, and lock it
+     * while we decide whether to be upstream or downstream.
+     */
+    mutexname = make_name(CONNSHARE_MUTEX_PREFIX, name);
+    mutex = lock_interprocess_mutex(mutexname, logtext);
+    if (!mutex) {
+        sfree(mutexname);
+        sfree(name);
+        return SHARE_NONE;
+    }
+
+    pipename = make_name(CONNSHARE_PIPE_PREFIX, name);
+
+    *logtext = NULL;
+
+    if (can_downstream) {
+        retsock = new_named_pipe_client(pipename, downplug);
+        if (sk_socket_error(retsock) == NULL) {
+            sfree(*logtext);
+            *logtext = pipename;
+            *sock = retsock;
+            sfree(name);
+            unlock_interprocess_mutex(mutex);
+            return SHARE_DOWNSTREAM;
+        }
+        sfree(*ds_err);
+        *ds_err = dupprintf("%s: %s", pipename, sk_socket_error(retsock));
+        sk_close(retsock);
+    }
+
+    if (can_upstream) {
+        retsock = new_named_pipe_listener(pipename, upplug);
+        if (sk_socket_error(retsock) == NULL) {
+            sfree(*logtext);
+            *logtext = pipename;
+            *sock = retsock;
+            sfree(name);
+            ReleaseMutex(mutex);
+            CloseHandle(mutex);
+            return SHARE_UPSTREAM;
+        }
+        sfree(*us_err);
+        *us_err = dupprintf("%s: %s", pipename, sk_socket_error(retsock));
+        sk_close(retsock);
+    }
+
+    /* One of the above clauses ought to have happened. */
+    assert(*logtext || *ds_err || *us_err);
+
+    sfree(pipename);
+    sfree(name);
+    ReleaseMutex(mutex);
+    CloseHandle(mutex);
+    return SHARE_NONE;
+}
+
+void platform_ssh_share_cleanup(const char *name)
+{
+}