Support --prefix-data in qrexec-client too

daemon/qrexec-client.c

@@ -86,6 +86,7 @@ static struct option longopts[] = {
     { "help", no_argument, 0, 'h' },
     { "socket-dir", required_argument, 0, opt_socket_dir },
     { "no-exit-code", no_argument, 0, 'E' },
+    { "prefix-data", required_argument, 0, 'p' },
     { "use-stdin-socket", no_argument, 0, opt_use_stdin_socket },
     { NULL, 0, 0, 0 },
 };
@@ -108,6 +109,7 @@ _Noreturn static void usage(const char *const name, int status)
             "  -w timeout - override default connection timeout of 5s (set 0 for no timeout)\n"
             "  -k - kill the domain right before exiting\n"
             "  --socket-dir=PATH -  directory for qrexec socket, default: %s\n"
+            "  -p PREFIX-DATA, --prefix-data=PREFIX-DATA - send the given data before the provided stdin (can only be used once)\n"
             "  --use-stdin-socket - use fd 0 (which must be socket) for both stdin and stdout\n",
             name ? name : "qrexec-client", QREXEC_DAEMON_SOCKET_DIR);
     exit(status);
@@ -177,11 +179,12 @@ int main(int argc, char **argv)
     bool replace_chars_stderr = false;
     bool wait_connection_end = false;
     bool exit_with_code = true;
+    const char *prefix_data = NULL;
     int rc = QREXEC_EXIT_PROBLEM;
 
     setup_logging("qrexec-client");
 
-    while ((opt = getopt_long(argc, argv, "hd:l:eEc:tTw:Wk", longopts, NULL)) != -1) {
+    while ((opt = getopt_long(argc, argv, "hd:l:eEc:p:tTw:Wk", longopts, NULL)) != -1) {
         switch (opt) {
             case 'd':
                 domname = xstrdup(optarg);
@@ -206,6 +209,11 @@ int main(int argc, char **argv)
                     usage(argv[0], 1);
                 }
                 break;
+            case 'p':
+                if (prefix_data)
+                    usage(argv[0], 2);
+                prefix_data = optarg;
+                break;
             case 't':
                 replace_chars_stdout = true;
                 break;
@@ -281,7 +289,8 @@ int main(int argc, char **argv)
                                     src_domain_name,
                                     remote_cmdline,
                                     connection_timeout,
-                                    exit_with_code);
+                                    exit_with_code,
+                                    prefix_data);
         } else {
             /* dom0 -> dom0 fake service call */
             assert(src_domain_id == 0);
@@ -398,6 +407,7 @@ int main(int argc, char **argv)
                 .exit_with_code = exit_with_code,
                 .replace_chars_stdout = replace_chars_stdout,
                 .replace_chars_stderr = replace_chars_stderr,
+                .prefix_data = prefix_data,
             };
             rc = handshake_and_go(&params, NULL);
 cleanup:

daemon/qrexec-daemon-common.c

@@ -478,8 +478,13 @@ static int select_loop(const struct handshake_params *params,
     req.data_protocol_version = params->data_protocol_version;
     req.sigchld = &sigchld;
     req.sigusr1 = NULL;
-    req.prefix_data.data = NULL;
-    req.prefix_data.len = 0;
+    if (params->prefix_data) {
+        req.prefix_data.data = params->prefix_data;
+        req.prefix_data.len = strlen(params->prefix_data);
+    } else {
+        req.prefix_data.data = NULL;
+        req.prefix_data.len = 0;
+    }
 
     exit_code = qrexec_process_io(&req, cmd);
     return (params->exit_with_code ? exit_code : 0);
@@ -490,7 +495,8 @@ int run_qrexec_to_dom0(const struct service_params *svc_params,
                         const char *src_domain_name,
                         char *remote_cmdline,
                         int connection_timeout,
-                        bool exit_with_code)
+                        bool exit_with_code,
+                        const char *prefix_data)
 {
     int data_domain;
     int data_port;
@@ -544,6 +550,7 @@ int run_qrexec_to_dom0(const struct service_params *svc_params,
         .exit_with_code = exit_with_code,
         .replace_chars_stdout = false, // stdout is _from_ dom0
         .replace_chars_stderr = false, // stderr is _from_ dom0
+        .prefix_data = prefix_data,
     };
     return handshake_and_go(&params, command);
 }

daemon/qrexec-daemon-common.h

@@ -72,7 +72,8 @@ int run_qrexec_to_dom0(const struct service_params *svc_params,
                        const char *src_domain_name,
                        char *remote_cmdline,
                        int connection_timeout,
-                       bool exit_with_code);
+                       bool exit_with_code,
+                       const char *prefix_data);
 /** Parameters for handshake_and_go(), organized as a struct
  * for convenience. */
 struct handshake_params {
@@ -97,6 +98,8 @@ struct handshake_params {
     bool replace_chars_stdout;
     /// Whether to replace problematic bytes with _ before writing to stderr.
     bool replace_chars_stderr;
+    /// Data to send after connecting
+    const char *prefix_data;
 };
 /**
  * Process IO call with the parameters specified by the parameters.

daemon/qrexec-daemon.c

@@ -1256,7 +1256,8 @@ _Noreturn static void handle_execute_service_child(
                            source_domain,
                            cmd,
                            5 /* 5 second timeout */,
-                           false /* return 0 not remote status code */));
+                           false /* return 0 not remote status code */,
+                           NULL /* prefix data */));
     } else {
         bool const use_uuid = target_uuid != NULL;
         const char *const selected_target = use_uuid ? target_uuid : target;

qrexec/tests/socket/daemon.py

@@ -733,7 +733,9 @@ def test_run_vm_command_from_dom0(self):
         target_daemon = self.connect_daemon(
             target_domain, target_domain_name, target_domain_uuid
         )
-        self.start_client(["-d", target_domain_name, cmd])
+        self.start_client(
+            ["-d", target_domain_name, "-p", "prefix data\n", cmd]
+        )
         target_daemon.accept()
         target_daemon.handshake(QREXEC_PROTOCOL_V3)
 
@@ -754,6 +756,9 @@ def test_run_vm_command_from_dom0(self):
         target.handshake()
 
         # select_loop
+        self.assertEqual(
+            target.recv_message(), (qrexec.MSG_DATA_STDIN, b"prefix data\n")
+        )
         target.send_message(qrexec.MSG_DATA_STDOUT, b"stdout data\n")
         target.send_message(qrexec.MSG_DATA_STDOUT, b"")
         self.assertEqual(self.client.stdout.read(), b"stdout data\n")
@@ -822,7 +827,7 @@ def test_run_vm_command_from_dom0_reject_stdin(self):
 
     def test_run_vm_command_from_dom0_with_local_command(self):
         cmd = "user:command"
-        local_cmd = "while read x; do echo input: $x; done; exit 44"
+        local_cmd = 'while read x; do echo input: "$x"; done; exit 44'
         target_domain_name = "target_domain"
         target_domain_uuid = "d95e1147-2d82-4595-90bb-5a7500cc3196"
         target_domain = 42
@@ -832,7 +837,15 @@ def test_run_vm_command_from_dom0_with_local_command(self):
             target_domain, target_domain_name, target_domain_uuid
         )
         self.start_client(
-            ["-d", "uuid:" + target_domain_uuid, "-l", local_cmd, cmd]
+            [
+                "-d",
+                "uuid:" + target_domain_uuid,
+                "-l",
+                local_cmd,
+                "-p",
+                "prefix data\n",
+                cmd,
+            ]
         )
         target_daemon.accept()
         target_daemon.handshake(QREXEC_PROTOCOL_V3)
@@ -854,6 +867,10 @@ def test_run_vm_command_from_dom0_with_local_command(self):
         target.handshake()
 
         # select_loop
+        self.assertEqual(
+            target.recv_message(),
+            (qrexec.MSG_DATA_STDIN, b"prefix data\n"),
+        )
         target.send_message(qrexec.MSG_DATA_STDOUT, b"stdout data\n")
         self.assertEqual(
             target.recv_message(),