bus-proxy: bring back systemd-stdio-bridge

Now that we want to make bus-proxy multi-threaded, we have to bring back
the systemd-stdio-bridge for our TCP use-cases.

1 files changed, 282 insertions, 0 deletions

diff --git a/src/bus-proxyd/stdio-bridge.c b/src/bus-proxyd/stdio-bridge.c
new file mode 100644
index 0000000000..711f74cacf
--- /dev/null
+++ b/src/bus-proxyd/stdio-bridge.c
@@ -0,0 +1,282 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+  Copyright 2013 Daniel Mack
+  Copyright 2014 Kay Sievers
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/poll.h>
+#include <stddef.h>
+#include <getopt.h>
+
+#include "log.h"
+#include "util.h"
+#include "socket-util.h"
+#include "sd-daemon.h"
+#include "sd-bus.h"
+#include "bus-internal.h"
+#include "bus-message.h"
+#include "bus-util.h"
+#include "build.h"
+#include "strv.h"
+#include "def.h"
+#include "capability.h"
+#include "bus-control.h"
+#include "smack-util.h"
+#include "set.h"
+#include "bus-xml-policy.h"
+#include "driver.h"
+#include "proxy.h"
+#include "synthesize.h"
+
+static char *arg_address = NULL;
+static char *arg_command_line_buffer = NULL;
+static char **arg_configuration = NULL;
+
+static int help(void) {
+
+        printf("%s [OPTIONS...]\n\n"
+               "Connect STDIO to a given bus address.\n\n"
+               "  -h --help               Show this help\n"
+               "     --version            Show package version\n"
+               "     --configuration=PATH Configuration file or directory\n"
+               "     --machine=MACHINE    Connect to specified machine\n"
+               "     --address=ADDRESS    Connect to the bus specified by ADDRESS\n"
+               "                          (default: " DEFAULT_SYSTEM_BUS_ADDRESS ")\n",
+               program_invocation_short_name);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_ADDRESS,
+                ARG_CONFIGURATION,
+                ARG_MACHINE,
+        };
+
+        static const struct option options[] = {
+                { "help",            no_argument,       NULL, 'h'                 },
+                { "version",         no_argument,       NULL, ARG_VERSION         },
+                { "address",         required_argument, NULL, ARG_ADDRESS         },
+                { "configuration",   required_argument, NULL, ARG_CONFIGURATION   },
+                { "machine",         required_argument, NULL, ARG_MACHINE         },
+                {},
+        };
+
+        int c, r;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
+
+                switch (c) {
+
+                case 'h':
+                        help();
+                        return 0;
+
+                case ARG_VERSION:
+                        puts(PACKAGE_STRING);
+                        puts(SYSTEMD_FEATURES);
+                        return 0;
+
+                case ARG_ADDRESS: {
+                        char *a;
+
+                        a = strdup(optarg);
+                        if (!a)
+                                return log_oom();
+
+                        free(arg_address);
+                        arg_address = a;
+                        break;
+                }
+
+                case ARG_CONFIGURATION:
+                        r = strv_extend(&arg_configuration, optarg);
+                        if (r < 0)
+                                return log_oom();
+                        break;
+
+                case ARG_MACHINE: {
+                        _cleanup_free_ char *e = NULL;
+                        char *a;
+
+                        e = bus_address_escape(optarg);
+                        if (!e)
+                                return log_oom();
+
+#ifdef ENABLE_KDBUS
+                        a = strjoin("x-machine-kernel:machine=", e, ";x-machine-unix:machine=", e, NULL);
+#else
+                        a = strjoin("x-machine-unix:machine=", e, NULL);
+#endif
+                        if (!a)
+                                return log_oom();
+
+                        free(arg_address);
+                        arg_address = a;
+
+                        break;
+                }
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached("Unhandled option");
+                }
+
+        /* If the first command line argument is only "x" characters
+         * we'll write who we are talking to into it, so that "ps" is
+         * explanatory */
+        arg_command_line_buffer = argv[optind];
+        if (argc > optind + 1 || (arg_command_line_buffer && !in_charset(arg_command_line_buffer, "x"))) {
+                log_error("Too many arguments");
+                return -EINVAL;
+        }
+
+        if (!arg_address) {
+                arg_address = strdup(DEFAULT_SYSTEM_BUS_ADDRESS);
+                if (!arg_address)
+                        return log_oom();
+        }
+
+        return 1;
+}
+
+static int rename_service(sd_bus *a, sd_bus *b) {
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        _cleanup_free_ char *p = NULL, *name = NULL;
+        const char *comm;
+        char **cmdline;
+        uid_t uid;
+        pid_t pid;
+        int r;
+
+        assert(a);
+        assert(b);
+
+        r = sd_bus_get_owner_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM|SD_BUS_CREDS_AUGMENT, &creds);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_get_uid(creds, &uid);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_get_pid(creds, &pid);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_get_cmdline(creds, &cmdline);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_get_comm(creds, &comm);
+        if (r < 0)
+                return r;
+
+        name = uid_to_name(uid);
+        if (!name)
+                return -ENOMEM;
+
+        p = strv_join(cmdline, " ");
+        if (!p)
+                return -ENOMEM;
+
+        /* The status string gets the full command line ... */
+        sd_notifyf(false,
+                   "STATUS=Processing requests from client PID "PID_FMT" (%s); UID "UID_FMT" (%s)",
+                   pid, p,
+                   uid, name);
+
+        /* ... and the argv line only the short comm */
+        if (arg_command_line_buffer) {
+                size_t m, w;
+
+                m = strlen(arg_command_line_buffer);
+                w = snprintf(arg_command_line_buffer, m,
+                             "[PID "PID_FMT"/%s; UID "UID_FMT"/%s]",
+                             pid, comm,
+                             uid, name);
+
+                if (m > w)
+                        memzero(arg_command_line_buffer + w, m - w);
+        }
+
+        log_debug("Running on behalf of PID "PID_FMT" (%s), UID "UID_FMT" (%s), %s",
+                  pid, p,
+                  uid, name,
+                  a->unique_name);
+
+        return 0;
+}
+
+int main(int argc, char *argv[]) {
+        _cleanup_(proxy_freep) Proxy *p = NULL;
+        int r;
+
+        log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        r = proxy_new(&p, STDIN_FILENO, STDOUT_FILENO, arg_address);
+        if (r < 0)
+                goto finish;
+
+        r = proxy_load_policy(p, arg_configuration);
+        if (r < 0)
+                goto finish;
+
+        r = proxy_hello_policy(p, getuid());
+        if (r < 0)
+                goto finish;
+
+        r = rename_service(p->dest_bus, p->local_bus);
+        if (r < 0)
+                log_debug_errno(r, "Failed to rename process: %m");
+
+        r = proxy_run(p);
+
+finish:
+        sd_notify(false,
+                  "STOPPING=1\n"
+                  "STATUS=Shutting down.");
+
+        strv_free(arg_configuration);
+        free(arg_address);
+
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}