src/libsystemd/sd-network/sd-network.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <poll.h>
   5 #include <sys/inotify.h>
   6
   7 #include "sd-network.h"
   8
   9 #include "alloc-util.h"
  10 #include "env-file.h"
  11 #include "fd-util.h"
  12 #include "fs-util.h"
  13 #include "macro.h"
  14 #include "parse-util.h"
  15 #include "stdio-util.h"
  16 #include "string-util.h"
  17 #include "strv.h"
  18 #include "util.h"
  19
  20 static int network_get_string(const char *field, char **ret) {
  21         _cleanup_free_ char *s = NULL;
  22         int r;
  23
  24         assert_return(ret, -EINVAL);
  25
  26         r = parse_env_file(NULL, "/run/systemd/netif/state", field, &s);
  27         if (r == -ENOENT)
  28                 return -ENODATA;
  29         if (r < 0)
  30                 return r;
  31         if (isempty(s))
  32                 return -ENODATA;
  33
  34         *ret = TAKE_PTR(s);
  35
  36         return 0;
  37 }
  38
  39 _public_ int sd_network_get_operational_state(char **state) {
  40         return network_get_string("OPER_STATE", state);
  41 }
  42
  43 _public_ int sd_network_get_carrier_state(char **state) {
  44         return network_get_string("CARRIER_STATE", state);
  45 }
  46
  47 _public_ int sd_network_get_address_state(char **state) {
  48         return network_get_string("ADDRESS_STATE", state);
  49 }
  50
  51 static int network_get_strv(const char *key, char ***ret) {
  52         _cleanup_strv_free_ char **a = NULL;
  53         _cleanup_free_ char *s = NULL;
  54         int r;
  55
  56         assert_return(ret, -EINVAL);
  57
  58         r = parse_env_file(NULL, "/run/systemd/netif/state", key, &s);
  59         if (r == -ENOENT)
  60                 return -ENODATA;
  61         if (r < 0)
  62                 return r;
  63         if (isempty(s)) {
  64                 *ret = NULL;
  65                 return 0;
  66         }
  67
  68         a = strv_split(s, " ");
  69         if (!a)
  70                 return -ENOMEM;
  71
  72         strv_uniq(a);
  73         r = (int) strv_length(a);
  74
  75         *ret = TAKE_PTR(a);
  76
  77         return r;
  78 }
  79
  80 _public_ int sd_network_get_dns(char ***ret) {
  81         return network_get_strv("DNS", ret);
  82 }
  83
  84 _public_ int sd_network_get_ntp(char ***ret) {
  85         return network_get_strv("NTP", ret);
  86 }
  87
  88 _public_ int sd_network_get_search_domains(char ***ret) {
  89         return network_get_strv("DOMAINS", ret);
  90 }
  91
  92 _public_ int sd_network_get_route_domains(char ***ret) {
  93         return network_get_strv("ROUTE_DOMAINS", ret);
  94 }
  95
  96 static int network_link_get_string(int ifindex, const char *field, char **ret) {
  97         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
  98         _cleanup_free_ char *s = NULL;
  99         int r;
 100
 101         assert_return(ifindex > 0, -EINVAL);
 102         assert_return(ret, -EINVAL);
 103
 104         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 105
 106         r = parse_env_file(NULL, path, field, &s);
 107         if (r == -ENOENT)
 108                 return -ENODATA;
 109         if (r < 0)
 110                 return r;
 111         if (isempty(s))
 112                 return -ENODATA;
 113
 114         *ret = TAKE_PTR(s);
 115
 116         return 0;
 117 }
 118
 119 static int network_link_get_strv(int ifindex, const char *key, char ***ret) {
 120         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
 121         _cleanup_strv_free_ char **a = NULL;
 122         _cleanup_free_ char *s = NULL;
 123         int r;
 124
 125         assert_return(ifindex > 0, -EINVAL);
 126         assert_return(ret, -EINVAL);
 127
 128         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 129         r = parse_env_file(NULL, path, key, &s);
 130         if (r == -ENOENT)
 131                 return -ENODATA;
 132         if (r < 0)
 133                 return r;
 134         if (isempty(s)) {
 135                 *ret = NULL;
 136                 return 0;
 137         }
 138
 139         a = strv_split(s, " ");
 140         if (!a)
 141                 return -ENOMEM;
 142
 143         strv_uniq(a);
 144         r = (int) strv_length(a);
 145
 146         *ret = TAKE_PTR(a);
 147
 148         return r;
 149 }
 150
 151 _public_ int sd_network_link_get_setup_state(int ifindex, char **state) {
 152         return network_link_get_string(ifindex, "ADMIN_STATE", state);
 153 }
 154
 155 _public_ int sd_network_link_get_network_file(int ifindex, char **filename) {
 156         return network_link_get_string(ifindex, "NETWORK_FILE", filename);
 157 }
 158
 159 _public_ int sd_network_link_get_operational_state(int ifindex, char **state) {
 160         return network_link_get_string(ifindex, "OPER_STATE", state);
 161 }
 162
 163 _public_ int sd_network_link_get_carrier_state(int ifindex, char **state) {
 164         return network_link_get_string(ifindex, "CARRIER_STATE", state);
 165 }
 166
 167 _public_ int sd_network_link_get_address_state(int ifindex, char **state) {
 168         return network_link_get_string(ifindex, "ADDRESS_STATE", state);
 169 }
 170
 171 _public_ int sd_network_link_get_dhcp6_client_iaid_string(int ifindex, char **iaid) {
 172         return network_link_get_string(ifindex, "DHCP6_CLIENT_IAID", iaid);
 173 }
 174
 175 _public_ int sd_network_link_get_dhcp6_client_duid_string(int ifindex, char **duid) {
 176         return network_link_get_string(ifindex, "DHCP6_CLIENT_DUID", duid);
 177 }
 178
 179 _public_ int sd_network_link_get_required_for_online(int ifindex) {
 180         _cleanup_free_ char *s = NULL;
 181         int r;
 182
 183         r = network_link_get_string(ifindex, "REQUIRED_FOR_ONLINE", &s);
 184         if (r < 0) {
 185                 /* Handle -ENODATA as RequiredForOnline=yes, for compatibility */
 186                 if (r == -ENODATA)
 187                         return true;
 188                 return r;
 189         }
 190
 191         return parse_boolean(s);
 192 }
 193
 194 _public_ int sd_network_link_get_required_operstate_for_online(int ifindex, char **state) {
 195         _cleanup_free_ char *s = NULL;
 196         int r;
 197
 198         assert_return(state, -EINVAL);
 199
 200         r = network_link_get_string(ifindex, "REQUIRED_OPER_STATE_FOR_ONLINE", &s);
 201         if (r < 0) {
 202                 if (r != -ENODATA)
 203                         return r;
 204
 205                 /* For compatibility, assuming degraded. */
 206                 s = strdup("degraded");
 207                 if (!s)
 208                         return -ENOMEM;
 209         }
 210
 211         *state = TAKE_PTR(s);
 212         return 0;
 213 }
 214
 215 _public_ int sd_network_link_get_activation_policy(int ifindex, char **policy) {
 216         _cleanup_free_ char *s = NULL;
 217         int r;
 218
 219         assert_return(policy, -EINVAL);
 220
 221         r = network_link_get_string(ifindex, "ACTIVATION_POLICY", &s);
 222         if (r < 0) {
 223                 if (r != -ENODATA)
 224                         return r;
 225
 226                 /* For compatibility, assuming up. */
 227                 s = strdup("up");
 228                 if (!s)
 229                         return -ENOMEM;
 230         }
 231
 232         *policy = TAKE_PTR(s);
 233         return 0;
 234 }
 235
 236 _public_ int sd_network_link_get_llmnr(int ifindex, char **llmnr) {
 237         return network_link_get_string(ifindex, "LLMNR", llmnr);
 238 }
 239
 240 _public_ int sd_network_link_get_mdns(int ifindex, char **mdns) {
 241         return network_link_get_string(ifindex, "MDNS", mdns);
 242 }
 243
 244 _public_ int sd_network_link_get_dns_over_tls(int ifindex, char **dns_over_tls) {
 245         return network_link_get_string(ifindex, "DNS_OVER_TLS", dns_over_tls);
 246 }
 247
 248 _public_ int sd_network_link_get_dnssec(int ifindex, char **dnssec) {
 249         return network_link_get_string(ifindex, "DNSSEC", dnssec);
 250 }
 251
 252 _public_ int sd_network_link_get_dnssec_negative_trust_anchors(int ifindex, char ***nta) {
 253         return network_link_get_strv(ifindex, "DNSSEC_NTA", nta);
 254 }
 255
 256 _public_ int sd_network_link_get_dns(int ifindex, char ***ret) {
 257         return network_link_get_strv(ifindex, "DNS", ret);
 258 }
 259
 260 _public_ int sd_network_link_get_ntp(int ifindex, char ***ret) {
 261         return network_link_get_strv(ifindex, "NTP", ret);
 262 }
 263
 264 _public_ int sd_network_link_get_sip(int ifindex, char ***ret) {
 265         return network_link_get_strv(ifindex, "SIP", ret);
 266 }
 267
 268 _public_ int sd_network_link_get_search_domains(int ifindex, char ***ret) {
 269         return network_link_get_strv(ifindex, "DOMAINS", ret);
 270 }
 271
 272 _public_ int sd_network_link_get_route_domains(int ifindex, char ***ret) {
 273         return network_link_get_strv(ifindex, "ROUTE_DOMAINS", ret);
 274 }
 275
 276 _public_ int sd_network_link_get_dns_default_route(int ifindex) {
 277         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
 278         _cleanup_free_ char *s = NULL;
 279         int r;
 280
 281         assert_return(ifindex > 0, -EINVAL);
 282
 283         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 284
 285         r = parse_env_file(NULL, path, "DNS_DEFAULT_ROUTE", &s);
 286         if (r == -ENOENT)
 287                 return -ENODATA;
 288         if (r < 0)
 289                 return r;
 290         if (isempty(s))
 291                 return -ENODATA;
 292         return parse_boolean(s);
 293 }
 294
 295 static int network_link_get_ifindexes(int ifindex, const char *key, int **ret) {
 296         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
 297         _cleanup_free_ int *ifis = NULL;
 298         _cleanup_free_ char *s = NULL;
 299         size_t allocated = 0, c = 0;
 300         int r;
 301
 302         assert_return(ifindex > 0, -EINVAL);
 303         assert_return(ret, -EINVAL);
 304
 305         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 306         r = parse_env_file(NULL, path, key, &s);
 307         if (r == -ENOENT)
 308                 return -ENODATA;
 309         if (r < 0)
 310                 return r;
 311
 312         for (const char *x = s;;) {
 313                 _cleanup_free_ char *word = NULL;
 314
 315                 r = extract_first_word(&x, &word, NULL, 0);
 316                 if (r < 0)
 317                         return r;
 318                 if (r == 0)
 319                         break;
 320
 321                 if (!GREEDY_REALLOC(ifis, allocated, c + 2))
 322                         return -ENOMEM;
 323
 324                 r = ifis[c++] = parse_ifindex(word);
 325                 if (r < 0)
 326                         return r;
 327         }
 328
 329         if (ifis)
 330                 ifis[c] = 0; /* Let's add a 0 ifindex to the end, to be nice */
 331
 332         *ret = TAKE_PTR(ifis);
 333
 334         return c;
 335 }
 336
 337 _public_ int sd_network_link_get_carrier_bound_to(int ifindex, int **ret) {
 338         return network_link_get_ifindexes(ifindex, "CARRIER_BOUND_TO", ret);
 339 }
 340
 341 _public_ int sd_network_link_get_carrier_bound_by(int ifindex, int **ret) {
 342         return network_link_get_ifindexes(ifindex, "CARRIER_BOUND_BY", ret);
 343 }
 344
 345 static int MONITOR_TO_FD(sd_network_monitor *m) {
 346         return (int) (unsigned long) m - 1;
 347 }
 348
 349 static sd_network_monitor* FD_TO_MONITOR(int fd) {
 350         return (sd_network_monitor*) (unsigned long) (fd + 1);
 351 }
 352
 353 static int monitor_add_inotify_watch(int fd) {
 354         int k;
 355
 356         k = inotify_add_watch(fd, "/run/systemd/netif/links/", IN_MOVED_TO|IN_DELETE);
 357         if (k >= 0)
 358                 return 0;
 359         else if (errno != ENOENT)
 360                 return -errno;
 361
 362         k = inotify_add_watch(fd, "/run/systemd/netif/", IN_CREATE|IN_ISDIR);
 363         if (k >= 0)
 364                 return 0;
 365         else if (errno != ENOENT)
 366                 return -errno;
 367
 368         k = inotify_add_watch(fd, "/run/systemd/", IN_CREATE|IN_ISDIR);
 369         if (k < 0)
 370                 return -errno;
 371
 372         return 0;
 373 }
 374
 375 _public_ int sd_network_monitor_new(sd_network_monitor **m, const char *category) {
 376         _cleanup_close_ int fd = -1;
 377         int k;
 378         bool good = false;
 379
 380         assert_return(m, -EINVAL);
 381
 382         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 383         if (fd < 0)
 384                 return -errno;
 385
 386         if (!category || streq(category, "links")) {
 387                 k = monitor_add_inotify_watch(fd);
 388                 if (k < 0)
 389                         return k;
 390
 391                 good = true;
 392         }
 393
 394         if (!good)
 395                 return -EINVAL;
 396
 397         *m = FD_TO_MONITOR(TAKE_FD(fd));
 398         return 0;
 399 }
 400
 401 _public_ sd_network_monitor* sd_network_monitor_unref(sd_network_monitor *m) {
 402         if (m)
 403                 close_nointr(MONITOR_TO_FD(m));
 404
 405         return NULL;
 406 }
 407
 408 _public_ int sd_network_monitor_flush(sd_network_monitor *m) {
 409         union inotify_event_buffer buffer;
 410         struct inotify_event *e;
 411         ssize_t l;
 412         int fd, k;
 413
 414         assert_return(m, -EINVAL);
 415
 416         fd = MONITOR_TO_FD(m);
 417
 418         l = read(fd, &buffer, sizeof(buffer));
 419         if (l < 0) {
 420                 if (IN_SET(errno, EAGAIN, EINTR))
 421                         return 0;
 422
 423                 return -errno;
 424         }
 425
 426         FOREACH_INOTIFY_EVENT(e, buffer, l) {
 427                 if (e->mask & IN_ISDIR) {
 428                         k = monitor_add_inotify_watch(fd);
 429                         if (k < 0)
 430                                 return k;
 431
 432                         k = inotify_rm_watch(fd, e->wd);
 433                         if (k < 0)
 434                                 return -errno;
 435                 }
 436         }
 437
 438         return 0;
 439 }
 440
 441 _public_ int sd_network_monitor_get_fd(sd_network_monitor *m) {
 442
 443         assert_return(m, -EINVAL);
 444
 445         return MONITOR_TO_FD(m);
 446 }
 447
 448 _public_ int sd_network_monitor_get_events(sd_network_monitor *m) {
 449
 450         assert_return(m, -EINVAL);
 451
 452         /* For now we will only return POLLIN here, since we don't
 453          * need anything else ever for inotify.  However, let's have
 454          * this API to keep our options open should we later on need
 455          * it. */
 456         return POLLIN;
 457 }
 458
 459 _public_ int sd_network_monitor_get_timeout(sd_network_monitor *m, uint64_t *timeout_usec) {
 460
 461         assert_return(m, -EINVAL);
 462         assert_return(timeout_usec, -EINVAL);
 463
 464         /* For now we will only return UINT64_MAX, since we don't
 465          * need any timeout. However, let's have this API to keep our
 466          * options open should we later on need it. */
 467         *timeout_usec = UINT64_MAX;
 468         return 0;
 469 }