aboutsummaryrefslogtreecommitdiffstats
path: root/src/resolve/resolvconf-compat.c
blob: 93ded6d56437b3d51f34f3b19c3af22abef65a3c (plain) (blame)
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
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <getopt.h>
#include <net/if.h>

#include "alloc-util.h"
#include "def.h"
#include "dns-domain.h"
#include "extract-word.h"
#include "fileio.h"
#include "parse-util.h"
#include "pretty-print.h"
#include "resolvconf-compat.h"
#include "resolvectl.h"
#include "resolved-def.h"
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"

static int resolvconf_help(void) {
        _cleanup_free_ char *link = NULL;
        int r;

        r = terminal_urlify_man("resolvectl", "1", &link);
        if (r < 0)
                return log_oom();

        printf("%1$s -a INTERFACE < FILE\n"
               "%1$s -d INTERFACE\n"
               "\n"
               "Register DNS server and domain configuration with systemd-resolved.\n\n"
               "  -h --help     Show this help\n"
               "     --version  Show package version\n"
               "  -a            Register per-interface DNS server and domain data\n"
               "  -d            Unregister per-interface DNS server and domain data\n"
               "  -f            Ignore if specified interface does not exist\n"
               "  -x            Send DNS traffic preferably over this interface\n"
               "\n"
               "This is a compatibility alias for the resolvectl(1) tool, providing native\n"
               "command line compatibility with the resolvconf(8) tool of various Linux\n"
               "distributions and BSD systems. Some options supported by other implementations\n"
               "are not supported and are ignored: -m, -p. Various options supported by other\n"
               "implementations are not supported and will cause the invocation to fail: -u,\n"
               "-I, -i, -l, -R, -r, -v, -V, --enable-updates, --disable-updates,\n"
               "--updates-are-enabled.\n"
               "\nSee the %2$s for details.\n",
               program_invocation_short_name,
               link);

        return 0;
}

static int parse_nameserver(const char *string) {
        int r;

        assert(string);

        for (;;) {
                _cleanup_free_ char *word = NULL;

                r = extract_first_word(&string, &word, NULL, 0);
                if (r < 0)
                        return r;
                if (r == 0)
                        break;

                if (strv_push(&arg_set_dns, word) < 0)
                        return log_oom();

                word = NULL;
        }

        return 0;
}

static int parse_search_domain(const char *string) {
        int r;

        assert(string);

        for (;;) {
                _cleanup_free_ char *word = NULL;

                r = extract_first_word(&string, &word, NULL, EXTRACT_UNQUOTE);
                if (r < 0)
                        return r;
                if (r == 0)
                        break;

                if (strv_push(&arg_set_domain, word) < 0)
                        return log_oom();

                word = NULL;
        }

        return 0;
}

int resolvconf_parse_argv(int argc, char *argv[]) {

        enum {
                ARG_VERSION = 0x100,
                ARG_ENABLE_UPDATES,
                ARG_DISABLE_UPDATES,
                ARG_UPDATES_ARE_ENABLED,
        };

        static const struct option options[] = {
                { "help",                no_argument, NULL, 'h'                     },
                { "version",             no_argument, NULL, ARG_VERSION             },

                /* The following are specific to Debian's original resolvconf */
                { "enable-updates",      no_argument, NULL, ARG_ENABLE_UPDATES      },
                { "disable-updates",     no_argument, NULL, ARG_DISABLE_UPDATES     },
                { "updates-are-enabled", no_argument, NULL, ARG_UPDATES_ARE_ENABLED },
                {}
        };

        enum {
                TYPE_REGULAR,
                TYPE_PRIVATE,   /* -p: Not supported, treated identically to TYPE_REGULAR */
                TYPE_EXCLUSIVE, /* -x */
        } type = TYPE_REGULAR;

        int c, r;

        assert(argc >= 0);
        assert(argv);

        /* openresolv checks these environment variables */
        if (getenv("IF_EXCLUSIVE"))
                type = TYPE_EXCLUSIVE;
        if (getenv("IF_PRIVATE"))
                type = TYPE_PRIVATE; /* not actually supported */

        arg_mode = _MODE_INVALID;

        while ((c = getopt_long(argc, argv, "hadxpfm:uIi:l:Rr:vV", options, NULL)) >= 0)
                switch(c) {

                case 'h':
                        return resolvconf_help();

                case ARG_VERSION:
                        return version();

                /* -a and -d is what everybody can agree on */
                case 'a':
                        arg_mode = MODE_SET_LINK;
                        break;

                case 'd':
                        arg_mode = MODE_REVERT_LINK;
                        break;

                /* The exclusive/private/force stuff is an openresolv invention, we support in some skewed way */
                case 'x':
                        type = TYPE_EXCLUSIVE;
                        break;

                case 'p':
                        type = TYPE_PRIVATE; /* not actually supported */
                        break;

                case 'f':
                        arg_ifindex_permissive = true;
                        break;

                /* The metrics stuff is an openresolv invention we ignore (and don't really need) */
                case 'm':
                        log_debug("Switch -%c ignored.", c);
                        break;

                /* Everybody else can agree on the existence of -u but we don't support it. */
                case 'u':

                /* The following options are openresolv inventions we don't support. */
                case 'I':
                case 'i':
                case 'l':
                case 'R':
                case 'r':
                case 'v':
                case 'V':
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "Switch -%c not supported.", c);

                /* The Debian resolvconf commands we don't support. */
                case ARG_ENABLE_UPDATES:
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "Switch --enable-updates not supported.");
                case ARG_DISABLE_UPDATES:
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "Switch --disable-updates not supported.");
                case ARG_UPDATES_ARE_ENABLED:
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "Switch --updates-are-enabled not supported.");

                case '?':
                        return -EINVAL;

                default:
                        assert_not_reached("Unhandled option");
                }

        if (arg_mode == _MODE_INVALID)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Expected either -a or -d on the command line.");

        if (optind+1 != argc)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Expected interface name as argument.");

        r = ifname_resolvconf_mangle(argv[optind]);
        if (r <= 0)
                return r;

        optind++;

        if (arg_mode == MODE_SET_LINK) {
                unsigned n = 0;

                for (;;) {
                        _cleanup_free_ char *line = NULL;
                        const char *a, *l;

                        r = read_line(stdin, LONG_LINE_MAX, &line);
                        if (r < 0)
                                return log_error_errno(r, "Failed to read from stdin: %m");
                        if (r == 0)
                                break;

                        n++;

                        l = strstrip(line);
                        if (IN_SET(*l, '#', ';', 0))
                                continue;

                        a = first_word(l, "nameserver");
                        if (a) {
                                (void) parse_nameserver(a);
                                continue;
                        }

                        a = first_word(l, "domain");
                        if (!a)
                                a = first_word(l, "search");
                        if (a) {
                                (void) parse_search_domain(a);
                                continue;
                        }

                        log_syntax(NULL, LOG_DEBUG, "stdin", n, 0, "Ignoring resolv.conf line: %s", l);
                }

                if (type == TYPE_EXCLUSIVE) {

                        /* If -x mode is selected, let's preferably route non-suffixed lookups to this interface. This
                         * somewhat matches the original -x behaviour */

                        r = strv_extend(&arg_set_domain, "~.");
                        if (r < 0)
                                return log_oom();

                } else if (type == TYPE_PRIVATE)
                        log_debug("Private DNS server data not supported, ignoring.");

                if (!arg_set_dns)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "No DNS servers specified, refusing operation.");
        }

        return 1; /* work to do */
}