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

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