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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2011 Lennart Poettering
   6   Copyright 2014 Tom Gundersen
   7 ***/
   8
   9 #include <errno.h>
  10 #include <poll.h>
  11 #include <string.h>
  12 #include <sys/inotify.h>
  13
  14 #include "sd-network.h"
  15
  16 #include "alloc-util.h"
  17 #include "fd-util.h"
  18 #include "fileio.h"
  19 #include "fs-util.h"
  20 #include "macro.h"
  21 #include "parse-util.h"
  22 #include "stdio-util.h"
  23 #include "string-util.h"
  24 #include "strv.h"
  25 #include "util.h"
  26
  27 _public_ int sd_network_get_operational_state(char **state) {
  28         _cleanup_free_ char *s = NULL;
  29         int r;
  30
  31         assert_return(state, -EINVAL);
  32
  33         r = parse_env_file("/run/systemd/netif/state", NEWLINE, "OPER_STATE", &s, NULL);
  34         if (r == -ENOENT)
  35                 return -ENODATA;
  36         if (r < 0)
  37                 return r;
  38         if (isempty(s))
  39                 return -ENODATA;
  40
  41         *state = TAKE_PTR(s);
  42
  43         return 0;
  44 }
  45
  46 static int network_get_strv(const char *key, char ***ret) {
  47         _cleanup_strv_free_ char **a = NULL;
  48         _cleanup_free_ char *s = NULL;
  49         int r;
  50
  51         assert_return(ret, -EINVAL);
  52
  53         r = parse_env_file("/run/systemd/netif/state", NEWLINE, key, &s, NULL);
  54         if (r == -ENOENT)
  55                 return -ENODATA;
  56         if (r < 0)
  57                 return r;
  58         if (isempty(s)) {
  59                 *ret = NULL;
  60                 return 0;
  61         }
  62
  63         a = strv_split(s, " ");
  64         if (!a)
  65                 return -ENOMEM;
  66
  67         strv_uniq(a);
  68         r = strv_length(a);
  69
  70         *ret = TAKE_PTR(a);
  71
  72         return r;
  73 }
  74
  75 _public_ int sd_network_get_dns(char ***ret) {
  76         return network_get_strv("DNS", ret);
  77 }
  78
  79 _public_ int sd_network_get_ntp(char ***ret) {
  80         return network_get_strv("NTP", ret);
  81 }
  82
  83 _public_ int sd_network_get_search_domains(char ***ret) {
  84         return network_get_strv("DOMAINS", ret);
  85 }
  86
  87 _public_ int sd_network_get_route_domains(char ***ret) {
  88         return network_get_strv("ROUTE_DOMAINS", ret);
  89 }
  90
  91 static int network_link_get_string(int ifindex, const char *field, char **ret) {
  92         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
  93         _cleanup_free_ char *s = NULL;
  94         int r;
  95
  96         assert_return(ifindex > 0, -EINVAL);
  97         assert_return(ret, -EINVAL);
  98
  99         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 100
 101         r = parse_env_file(path, NEWLINE, field, &s, NULL);
 102         if (r == -ENOENT)
 103                 return -ENODATA;
 104         if (r < 0)
 105                 return r;
 106         if (isempty(s))
 107                 return -ENODATA;
 108
 109         *ret = TAKE_PTR(s);
 110
 111         return 0;
 112 }
 113
 114 static int network_link_get_strv(int ifindex, const char *key, char ***ret) {
 115         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
 116         _cleanup_strv_free_ char **a = NULL;
 117         _cleanup_free_ char *s = NULL;
 118         int r;
 119
 120         assert_return(ifindex > 0, -EINVAL);
 121         assert_return(ret, -EINVAL);
 122
 123         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 124         r = parse_env_file(path, NEWLINE, key, &s, NULL);
 125         if (r == -ENOENT)
 126                 return -ENODATA;
 127         if (r < 0)
 128                 return r;
 129         if (isempty(s)) {
 130                 *ret = NULL;
 131                 return 0;
 132         }
 133
 134         a = strv_split(s, " ");
 135         if (!a)
 136                 return -ENOMEM;
 137
 138         strv_uniq(a);
 139         r = strv_length(a);
 140
 141         *ret = TAKE_PTR(a);
 142
 143         return r;
 144 }
 145
 146 _public_ int sd_network_link_get_setup_state(int ifindex, char **state) {
 147         return network_link_get_string(ifindex, "ADMIN_STATE", state);
 148 }
 149
 150 _public_ int sd_network_link_get_network_file(int ifindex, char **filename) {
 151         return network_link_get_string(ifindex, "NETWORK_FILE", filename);
 152 }
 153
 154 _public_ int sd_network_link_get_operational_state(int ifindex, char **state) {
 155         return network_link_get_string(ifindex, "OPER_STATE", state);
 156 }
 157
 158 _public_ int sd_network_link_get_required_for_online(int ifindex) {
 159         _cleanup_free_ char *s = NULL;
 160         int r;
 161
 162         r = network_link_get_string(ifindex, "REQUIRED_FOR_ONLINE", &s);
 163         if (r < 0) {
 164                 /* Handle -ENODATA as RequiredForOnline=yes, for compatibility */
 165                 if (r == -ENODATA)
 166                         return true;
 167                 return r;
 168         }
 169
 170         return parse_boolean(s);
 171 }
 172
 173 _public_ int sd_network_link_get_llmnr(int ifindex, char **llmnr) {
 174         return network_link_get_string(ifindex, "LLMNR", llmnr);
 175 }
 176
 177 _public_ int sd_network_link_get_mdns(int ifindex, char **mdns) {
 178         return network_link_get_string(ifindex, "MDNS", mdns);
 179 }
 180
 181 _public_ int sd_network_link_get_dnssec(int ifindex, char **dnssec) {
 182         return network_link_get_string(ifindex, "DNSSEC", dnssec);
 183 }
 184
 185 _public_ int sd_network_link_get_dnssec_negative_trust_anchors(int ifindex, char ***nta) {
 186         return network_link_get_strv(ifindex, "DNSSEC_NTA", nta);
 187 }
 188
 189 _public_ int sd_network_link_get_timezone(int ifindex, char **ret) {
 190         return network_link_get_string(ifindex, "TIMEZONE", ret);
 191 }
 192
 193 _public_ int sd_network_link_get_dns(int ifindex, char ***ret) {
 194         return network_link_get_strv(ifindex, "DNS", ret);
 195 }
 196
 197 _public_ int sd_network_link_get_ntp(int ifindex, char ***ret) {
 198         return network_link_get_strv(ifindex, "NTP", ret);
 199 }
 200
 201 _public_ int sd_network_link_get_search_domains(int ifindex, char ***ret) {
 202         return network_link_get_strv(ifindex, "DOMAINS", ret);
 203 }
 204
 205 _public_ int sd_network_link_get_route_domains(int ifindex, char ***ret) {
 206         return network_link_get_strv(ifindex, "ROUTE_DOMAINS", ret);
 207 }
 208
 209 static int network_link_get_ifindexes(int ifindex, const char *key, int **ret) {
 210         char path[STRLEN("/run/systemd/netif/links/") + DECIMAL_STR_MAX(ifindex) + 1];
 211         _cleanup_free_ int *ifis = NULL;
 212         _cleanup_free_ char *s = NULL;
 213         size_t allocated = 0, c = 0;
 214         const char *x;
 215         int r;
 216
 217         assert_return(ifindex > 0, -EINVAL);
 218         assert_return(ret, -EINVAL);
 219
 220         xsprintf(path, "/run/systemd/netif/links/%i", ifindex);
 221         r = parse_env_file(path, NEWLINE, key, &s, NULL);
 222         if (r == -ENOENT)
 223                 return -ENODATA;
 224         if (r < 0)
 225                 return r;
 226
 227         for (x = s;;) {
 228                 _cleanup_free_ char *word = NULL;
 229
 230                 r = extract_first_word(&x, &word, NULL, 0);
 231                 if (r < 0)
 232                         return r;
 233                 if (r == 0)
 234                         break;
 235
 236                 r = parse_ifindex(word, &ifindex);
 237                 if (r < 0)
 238                         return r;
 239
 240                 if (!GREEDY_REALLOC(ifis, allocated, c + 2))
 241                         return -ENOMEM;
 242
 243                 ifis[c++] = ifindex;
 244         }
 245
 246         if (ifis)
 247                 ifis[c] = 0; /* Let's add a 0 ifindex to the end, to be nice */
 248
 249         *ret = TAKE_PTR(ifis);
 250
 251         return c;
 252 }
 253
 254 _public_ int sd_network_link_get_carrier_bound_to(int ifindex, int **ret) {
 255         return network_link_get_ifindexes(ifindex, "CARRIER_BOUND_TO", ret);
 256 }
 257
 258 _public_ int sd_network_link_get_carrier_bound_by(int ifindex, int **ret) {
 259         return network_link_get_ifindexes(ifindex, "CARRIER_BOUND_BY", ret);
 260 }
 261
 262 static inline int MONITOR_TO_FD(sd_network_monitor *m) {
 263         return (int) (unsigned long) m - 1;
 264 }
 265
 266 static inline sd_network_monitor* FD_TO_MONITOR(int fd) {
 267         return (sd_network_monitor*) (unsigned long) (fd + 1);
 268 }
 269
 270 static int monitor_add_inotify_watch(int fd) {
 271         int k;
 272
 273         k = inotify_add_watch(fd, "/run/systemd/netif/links/", IN_MOVED_TO|IN_DELETE);
 274         if (k >= 0)
 275                 return 0;
 276         else if (errno != ENOENT)
 277                 return -errno;
 278
 279         k = inotify_add_watch(fd, "/run/systemd/netif/", IN_CREATE|IN_ISDIR);
 280         if (k >= 0)
 281                 return 0;
 282         else if (errno != ENOENT)
 283                 return -errno;
 284
 285         k = inotify_add_watch(fd, "/run/systemd/", IN_CREATE|IN_ISDIR);
 286         if (k < 0)
 287                 return -errno;
 288
 289         return 0;
 290 }
 291
 292 _public_ int sd_network_monitor_new(sd_network_monitor **m, const char *category) {
 293         _cleanup_close_ int fd = -1;
 294         int k;
 295         bool good = false;
 296
 297         assert_return(m, -EINVAL);
 298
 299         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 300         if (fd < 0)
 301                 return -errno;
 302
 303         if (!category || streq(category, "links")) {
 304                 k = monitor_add_inotify_watch(fd);
 305                 if (k < 0)
 306                         return k;
 307
 308                 good = true;
 309         }
 310
 311         if (!good)
 312                 return -EINVAL;
 313
 314         *m = FD_TO_MONITOR(fd);
 315         fd = -1;
 316
 317         return 0;
 318 }
 319
 320 _public_ sd_network_monitor* sd_network_monitor_unref(sd_network_monitor *m) {
 321         int fd;
 322
 323         if (m) {
 324                 fd = MONITOR_TO_FD(m);
 325                 close_nointr(fd);
 326         }
 327
 328         return NULL;
 329 }
 330
 331 _public_ int sd_network_monitor_flush(sd_network_monitor *m) {
 332         union inotify_event_buffer buffer;
 333         struct inotify_event *e;
 334         ssize_t l;
 335         int fd, k;
 336
 337         assert_return(m, -EINVAL);
 338
 339         fd = MONITOR_TO_FD(m);
 340
 341         l = read(fd, &buffer, sizeof(buffer));
 342         if (l < 0) {
 343                 if (IN_SET(errno, EAGAIN, EINTR))
 344                         return 0;
 345
 346                 return -errno;
 347         }
 348
 349         FOREACH_INOTIFY_EVENT(e, buffer, l) {
 350                 if (e->mask & IN_ISDIR) {
 351                         k = monitor_add_inotify_watch(fd);
 352                         if (k < 0)
 353                                 return k;
 354
 355                         k = inotify_rm_watch(fd, e->wd);
 356                         if (k < 0)
 357                                 return -errno;
 358                 }
 359         }
 360
 361         return 0;
 362 }
 363
 364 _public_ int sd_network_monitor_get_fd(sd_network_monitor *m) {
 365
 366         assert_return(m, -EINVAL);
 367
 368         return MONITOR_TO_FD(m);
 369 }
 370
 371 _public_ int sd_network_monitor_get_events(sd_network_monitor *m) {
 372
 373         assert_return(m, -EINVAL);
 374
 375         /* For now we will only return POLLIN here, since we don't
 376          * need anything else ever for inotify.  However, let's have
 377          * this API to keep our options open should we later on need
 378          * it. */
 379         return POLLIN;
 380 }
 381
 382 _public_ int sd_network_monitor_get_timeout(sd_network_monitor *m, uint64_t *timeout_usec) {
 383
 384         assert_return(m, -EINVAL);
 385         assert_return(timeout_usec, -EINVAL);
 386
 387         /* For now we will only return (uint64_t) -1, since we don't
 388          * need any timeout. However, let's have this API to keep our
 389          * options open should we later on need it. */
 390         *timeout_usec = (uint64_t) -1;
 391         return 0;
 392 }