1 files changed, 116 insertions, 0 deletions
diff --git a/unix/local-proxy.c b/unix/local-proxy.c
new file mode 100644
index 00000000..157f9207
--- /dev/null
+++ b/unix/local-proxy.c
@@ -0,0 +1,116 @@
+/*
+ * local-proxy.c: Unix implementation of platform_new_connection(),
+ * supporting an OpenSSH-like proxy command.
+ */
+
+#include <stdio.h>
+#include <assert.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "tree234.h"
+#include "putty.h"
+#include "network.h"
+#include "proxy/proxy.h"
+
+char *platform_setup_local_proxy(Socket *socket, const char *cmd)
+{
+    /*
+     * Create the pipes to the proxy command, and spawn the proxy
+     * command process.
+     */
+    int to_cmd_pipe[2], from_cmd_pipe[2], cmd_err_pipe[2];
+    if (pipe(to_cmd_pipe) < 0 ||
+        pipe(from_cmd_pipe) < 0 ||
+        pipe(cmd_err_pipe) < 0) {
+        return dupprintf("pipe: %s", strerror(errno));
+    }
+    cloexec(to_cmd_pipe[1]);
+    cloexec(from_cmd_pipe[0]);
+    cloexec(cmd_err_pipe[0]);
+
+    int pid = fork();
+    if (pid == 0) {
+        close(0);
+        close(1);
+        dup2(to_cmd_pipe[0], 0);
+        dup2(from_cmd_pipe[1], 1);
+        close(to_cmd_pipe[0]);
+        close(from_cmd_pipe[1]);
+        dup2(cmd_err_pipe[1], 2);
+        noncloexec(0);
+        noncloexec(1);
+        execl("/bin/sh", "sh", "-c", cmd, (void *)NULL);
+        _exit(255);
+    }
+
+    if (pid < 0) {
+        return dupprintf("fork: %s", strerror(errno));
+    }
+
+    close(to_cmd_pipe[0]);
+    close(from_cmd_pipe[1]);
+    close(cmd_err_pipe[1]);
+
+    setup_fd_socket(socket, from_cmd_pipe[0], to_cmd_pipe[1], cmd_err_pipe[0]);
+
+    return NULL;
+}
+
+Socket *platform_new_connection(SockAddr *addr, const char *hostname,
+                                int port, bool privport,
+                                bool oobinline, bool nodelay, bool keepalive,
+                                Plug *plug, Conf *conf, Interactor *itr)
+{
+    switch (conf_get_int(conf, CONF_proxy_type)) {
+      case PROXY_CMD: {
+        DeferredSocketOpener *opener = local_proxy_opener(
+            addr, port, plug, conf, itr);
+        Socket *socket = make_deferred_fd_socket(opener, addr, port, plug);
+        local_proxy_opener_set_socket(opener, socket);
+        return socket;
+      }
+
+      case PROXY_FUZZ: {
+        char *cmd = format_telnet_command(addr, port, conf, NULL);
+        int outfd = open("/dev/null", O_WRONLY);
+        if (outfd == -1) {
+            sfree(cmd);
+            return new_error_socket_fmt(
+                plug, "/dev/null: %s", strerror(errno));
+        }
+        int infd = open(cmd, O_RDONLY);
+        if (infd == -1) {
+            Socket *toret = new_error_socket_fmt(
+                plug, "%s: %s", cmd, strerror(errno));
+            sfree(cmd);
+            close(outfd);
+            return toret;
+        }
+        sfree(cmd);
+        return make_fd_socket(infd, outfd, -1, addr, port, plug);
+      }
+
+      default:
+        return NULL;
+    }
+}
+
+Socket *platform_start_subprocess(const char *cmd, Plug *plug,
+                                  const char *prefix)
+{
+    Socket *socket = make_deferred_fd_socket(
+        null_deferred_socket_opener(),
+        sk_nonamelookup("<local command>"), 0, plug);
+    char *err = platform_setup_local_proxy(socket, cmd);
+    fd_socket_set_psb_prefix(socket, prefix);
+
+    if (err) {
+        sk_close(socket);
+        socket = new_error_socket_fmt(plug, "%s", err);
+        sfree(err);
+    }
+
+    return socket;
+}