src/nss-mymachines/nss-mymachines.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <nss.h>
  23 #include <netdb.h>
  24
  25 #include "sd-bus.h"
  26 #include "sd-login.h"
  27 #include "macro.h"
  28 #include "util.h"
  29 #include "nss-util.h"
  30 #include "bus-util.h"
  31 #include "in-addr-util.h"
  32
  33 NSS_GETHOSTBYNAME_PROTOTYPES(mymachines);
  34
  35 static int count_addresses(sd_bus_message *m, int af, unsigned *ret) {
  36         unsigned c = 0;
  37         int r;
  38
  39         assert(m);
  40         assert(ret);
  41
  42         while ((r = sd_bus_message_enter_container(m, 'r', "iay")) > 0) {
  43                 int family;
  44
  45                 r = sd_bus_message_read(m, "i", &family);
  46                 if (r < 0)
  47                         return r;
  48
  49                 r = sd_bus_message_skip(m, "ay");
  50                 if (r < 0)
  51                         return r;
  52
  53                 r = sd_bus_message_exit_container(m);
  54                 if (r < 0)
  55                         return r;
  56
  57                 if (af != AF_UNSPEC && family != af)
  58                         continue;
  59
  60                 c ++;
  61         }
  62         if (r < 0)
  63                 return r;
  64
  65         r = sd_bus_message_rewind(m, false);
  66         if (r < 0)
  67                 return r;
  68
  69         *ret = c;
  70         return 0;
  71 }
  72
  73 enum nss_status _nss_mymachines_gethostbyname4_r(
  74                 const char *name,
  75                 struct gaih_addrtuple **pat,
  76                 char *buffer, size_t buflen,
  77                 int *errnop, int *h_errnop,
  78                 int32_t *ttlp) {
  79
  80         struct gaih_addrtuple *r_tuple, *r_tuple_first = NULL;
  81         _cleanup_bus_message_unref_ sd_bus_message* reply = NULL;
  82         _cleanup_bus_close_unref_ sd_bus *bus = NULL;
  83         _cleanup_free_ int *ifindices = NULL;
  84         _cleanup_free_ char *class = NULL;
  85         size_t l, ms, idx;
  86         unsigned i = 0, c = 0;
  87         char *r_name;
  88         int n_ifindices, r;
  89
  90         assert(name);
  91         assert(pat);
  92         assert(buffer);
  93         assert(errnop);
  94         assert(h_errnop);
  95
  96         r = sd_machine_get_class(name, &class);
  97         if (r < 0)
  98                 goto fail;
  99         if (!streq(class, "container")) {
 100                 r = -ENOTTY;
 101                 goto fail;
 102         }
 103
 104         n_ifindices = sd_machine_get_ifindices(name, &ifindices);
 105         if (n_ifindices < 0) {
 106                 r = n_ifindices;
 107                 goto fail;
 108         }
 109
 110         r = sd_bus_open_system(&bus);
 111         if (r < 0)
 112                 goto fail;
 113
 114         r = sd_bus_call_method(bus,
 115                                "org.freedesktop.machine1",
 116                                "/org/freedesktop/machine1",
 117                                "org.freedesktop.machine1.Manager",
 118                                "GetMachineAddresses",
 119                                NULL,
 120                                &reply,
 121                                "s", name);
 122         if (r < 0)
 123                 goto fail;
 124
 125         r = sd_bus_message_enter_container(reply, 'a', "(iay)");
 126         if (r < 0)
 127                 goto fail;
 128
 129         r = count_addresses(reply, AF_UNSPEC, &c);
 130         if (r < 0)
 131                 goto fail;
 132
 133         if (c <= 0) {
 134                 *errnop = ESRCH;
 135                 *h_errnop = HOST_NOT_FOUND;
 136                 return NSS_STATUS_NOTFOUND;
 137         }
 138
 139         l = strlen(name);
 140         ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c;
 141         if (buflen < ms) {
 142                 *errnop = ENOMEM;
 143                 *h_errnop = TRY_AGAIN;
 144                 return NSS_STATUS_TRYAGAIN;
 145         }
 146
 147         /* First, append name */
 148         r_name = buffer;
 149         memcpy(r_name, name, l+1);
 150         idx = ALIGN(l+1);
 151
 152         /* Second, append addresses */
 153         r_tuple_first = (struct gaih_addrtuple*) (buffer + idx);
 154         while ((r = sd_bus_message_enter_container(reply, 'r', "iay")) > 0) {
 155                 int family;
 156                 const void *a;
 157                 size_t sz;
 158
 159                 r = sd_bus_message_read(reply, "i", &family);
 160                 if (r < 0)
 161                         goto fail;
 162
 163                 r = sd_bus_message_read_array(reply, 'y', &a, &sz);
 164                 if (r < 0)
 165                         goto fail;
 166
 167                 r = sd_bus_message_exit_container(reply);
 168                 if (r < 0)
 169                         goto fail;
 170
 171                 if (!IN_SET(family, AF_INET, AF_INET6)) {
 172                         r = -EAFNOSUPPORT;
 173                         goto fail;
 174                 }
 175
 176                 if (sz != FAMILY_ADDRESS_SIZE(family)) {
 177                         r = -EINVAL;
 178                         goto fail;
 179                 }
 180
 181                 r_tuple = (struct gaih_addrtuple*) (buffer + idx);
 182                 r_tuple->next = i == c-1 ? NULL : (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple)));
 183                 r_tuple->name = r_name;
 184                 r_tuple->family = family;
 185                 r_tuple->scopeid = n_ifindices == 1 ? ifindices[0] : 0;
 186                 memcpy(r_tuple->addr, a, sz);
 187
 188                 idx += ALIGN(sizeof(struct gaih_addrtuple));
 189                 i++;
 190         }
 191
 192         assert(i == c);
 193
 194         r = sd_bus_message_exit_container(reply);
 195         if (r < 0)
 196                 goto fail;
 197
 198         assert(idx == ms);
 199
 200         if (*pat)
 201                 **pat = *r_tuple_first;
 202         else
 203                 *pat = r_tuple_first;
 204
 205         if (ttlp)
 206                 *ttlp = 0;
 207
 208         /* Explicitly reset all error variables */
 209         *errnop = 0;
 210         *h_errnop = NETDB_SUCCESS;
 211         h_errno = 0;
 212
 213         return NSS_STATUS_SUCCESS;
 214
 215 fail:
 216         *errnop = -r;
 217         *h_errnop = NO_DATA;
 218         return NSS_STATUS_UNAVAIL;
 219 }
 220
 221 enum nss_status _nss_mymachines_gethostbyname3_r(
 222                 const char *name,
 223                 int af,
 224                 struct hostent *result,
 225                 char *buffer, size_t buflen,
 226                 int *errnop, int *h_errnop,
 227                 int32_t *ttlp,
 228                 char **canonp) {
 229
 230         _cleanup_bus_message_unref_ sd_bus_message* reply = NULL;
 231         _cleanup_bus_close_unref_ sd_bus *bus = NULL;
 232         _cleanup_free_ char *class = NULL;
 233         unsigned c = 0, i = 0;
 234         char *r_name, *r_aliases, *r_addr, *r_addr_list;
 235         size_t l, idx, ms, alen;
 236         int r;
 237
 238         assert(name);
 239         assert(result);
 240         assert(buffer);
 241         assert(errnop);
 242         assert(h_errnop);
 243
 244         if (af == AF_UNSPEC)
 245                 af = AF_INET;
 246
 247         if (af != AF_INET && af != AF_INET6) {
 248                 r = -EAFNOSUPPORT;
 249                 goto fail;
 250         }
 251
 252         r = sd_machine_get_class(name, &class);
 253         if (r < 0)
 254                 goto fail;
 255         if (!streq(class, "container")) {
 256                 r = -ENOTTY;
 257                 goto fail;
 258         }
 259
 260         r = sd_bus_open_system(&bus);
 261         if (r < 0)
 262                 goto fail;
 263
 264         r = sd_bus_call_method(bus,
 265                                "org.freedesktop.machine1",
 266                                "/org/freedesktop/machine1",
 267                                "org.freedesktop.machine1.Manager",
 268                                "GetMachineAddresses",
 269                                NULL,
 270                                &reply,
 271                                "s", name);
 272         if (r < 0)
 273                 goto fail;
 274
 275         r = sd_bus_message_enter_container(reply, 'a', "(iay)");
 276         if (r < 0)
 277                 goto fail;
 278
 279         r = count_addresses(reply, af, &c);
 280         if (r < 0)
 281                 goto fail;
 282
 283         if (c <= 0) {
 284                 *errnop = ENOENT;
 285                 *h_errnop = HOST_NOT_FOUND;
 286                 return NSS_STATUS_NOTFOUND;
 287         }
 288
 289         alen = FAMILY_ADDRESS_SIZE(af);
 290         l = strlen(name);
 291
 292         ms = ALIGN(l+1) +
 293                 sizeof(char*) +
 294                 (c > 0 ? c : 1) * ALIGN(alen) +
 295                 (c > 0 ? c+1 : 2) * sizeof(char*);
 296
 297         if (buflen < ms) {
 298                 *errnop = ENOMEM;
 299                 *h_errnop = NO_RECOVERY;
 300                 return NSS_STATUS_TRYAGAIN;
 301         }
 302
 303         /* First, append name */
 304         r_name = buffer;
 305         memcpy(r_name, name, l+1);
 306         idx = ALIGN(l+1);
 307
 308         /* Second, create aliases array */
 309         r_aliases = buffer + idx;
 310         ((char**) r_aliases)[0] = NULL;
 311         idx += sizeof(char*);
 312
 313         /* Third, append addresses */
 314         r_addr = buffer + idx;
 315         while ((r = sd_bus_message_enter_container(reply, 'r', "iay")) > 0) {
 316                 int family;
 317                 const void *a;
 318                 size_t sz;
 319
 320                 r = sd_bus_message_read(reply, "i", &family);
 321                 if (r < 0)
 322                         goto fail;
 323
 324                 r = sd_bus_message_read_array(reply, 'y', &a, &sz);
 325                 if (r < 0)
 326                         goto fail;
 327
 328                 r = sd_bus_message_exit_container(reply);
 329                 if (r < 0)
 330                         goto fail;
 331
 332                 if (family != af)
 333                         continue;
 334
 335                 if (sz != alen) {
 336                         r = -EINVAL;
 337                         goto fail;
 338                 }
 339
 340                 memcpy(r_addr + i*ALIGN(alen), a, alen);
 341                 i++;
 342         }
 343
 344         assert(i == c);
 345         idx += c * ALIGN(alen);
 346
 347         r = sd_bus_message_exit_container(reply);
 348         if (r < 0)
 349                 goto fail;
 350
 351         /* Third, append address pointer array */
 352         r_addr_list = buffer + idx;
 353         for (i = 0; i < c; i++)
 354                 ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen);
 355
 356         ((char**) r_addr_list)[i] = NULL;
 357         idx += (c+1) * sizeof(char*);
 358
 359         assert(idx == ms);
 360
 361         result->h_name = r_name;
 362         result->h_aliases = (char**) r_aliases;
 363         result->h_addrtype = af;
 364         result->h_length = alen;
 365         result->h_addr_list = (char**) r_addr_list;
 366
 367         if (ttlp)
 368                 *ttlp = 0;
 369
 370         if (canonp)
 371                 *canonp = r_name;
 372
 373         /* Explicitly reset all error variables */
 374         *errnop = 0;
 375         *h_errnop = NETDB_SUCCESS;
 376         h_errno = 0;
 377
 378         return NSS_STATUS_SUCCESS;
 379
 380 fail:
 381         *errnop = -r;
 382         *h_errnop = NO_DATA;
 383         return NSS_STATUS_UNAVAIL;
 384 }
 385
 386 NSS_GETHOSTBYNAME_FALLBACKS(mymachines)