summaryrefslogtreecommitdiff
path: root/src/bus-proxyd/stdio-bridge.c
blob: 60c4a0832598c4ff52173c70f96e0ad3166fe9e4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/***
  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 <errno.h>
#include <getopt.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>

#include <systemd/sd-bus.h>
#include <systemd/sd-daemon.h>

#include "alloc-util.h"
#include "bus-internal.h"
#include "bus-util.h"
#include "def.h"
#include "formats-util.h"
#include "log.h"
#include "proxy.h"
#include "strv.h"
#include "user-util.h"
#include "util.h"

static char *arg_address = NULL;
static char *arg_command_line_buffer = 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"
               "     --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_MACHINE,
        };

        static const struct option options[] = {
                { "help",            no_argument,       NULL, 'h'                 },
                { "version",         no_argument,       NULL, ARG_VERSION         },
                { "address",         required_argument, NULL, ARG_ADDRESS         },
                { "machine",         required_argument, NULL, ARG_MACHINE         },
                {},
        };

        int c;

        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:
                        return version();

                case ARG_ADDRESS: {
                        char *a;

                        a = strdup(optarg);
                        if (!a)
                                return log_oom();

                        free(arg_address);
                        arg_address = a;
                        break;
                }

                case ARG_MACHINE: {
                        _cleanup_free_ char *e = NULL;
                        char *a;

                        e = bus_address_escape(optarg);
                        if (!e)
                                return log_oom();

                        a = strjoin("x-machine-kernel:machine=", e, ";x-machine-unix:machine=", e, NULL);
                        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_(sd_bus_creds_unrefp) 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_EUID|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_euid(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 = rename_service(p->destination_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.");

        free(arg_address);

        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}