src/core/unit-printf.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 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 "systemd/sd-id128.h"
  23 #include "unit.h"
  24 #include "specifier.h"
  25 #include "path-util.h"
  26 #include "strv.h"
  27 #include "unit-name.h"
  28 #include "unit-printf.h"
  29 #include "macro.h"
  30 #include "cgroup-util.h"
  31 #include "special.h"
  32
  33 static int specifier_prefix_and_instance(char specifier, void *data, void *userdata, char **ret) {
  34         Unit *u = userdata;
  35         char *n;
  36
  37         assert(u);
  38
  39         n = unit_name_to_prefix_and_instance(u->id);
  40         if (!n)
  41                 return -ENOMEM;
  42
  43         *ret = n;
  44         return 0;
  45 }
  46
  47 static int specifier_prefix(char specifier, void *data, void *userdata, char **ret) {
  48         Unit *u = userdata;
  49         char *n;
  50
  51         assert(u);
  52
  53         n = unit_name_to_prefix(u->id);
  54         if (!n)
  55                 return -ENOMEM;
  56
  57         *ret = n;
  58         return 0;
  59 }
  60
  61 static int specifier_prefix_unescaped(char specifier, void *data, void *userdata, char **ret) {
  62         Unit *u = userdata;
  63         _cleanup_free_ char *p = NULL;
  64         char *n;
  65
  66         assert(u);
  67
  68         p = unit_name_to_prefix(u->id);
  69         if (!p)
  70                 return -ENOMEM;
  71
  72         n = unit_name_unescape(p);
  73         if (!n)
  74                 return -ENOMEM;
  75
  76         *ret = n;
  77         return 0;
  78 }
  79
  80 static int specifier_instance_unescaped(char specifier, void *data, void *userdata, char **ret) {
  81         Unit *u = userdata;
  82         char *n;
  83
  84         assert(u);
  85
  86         if (!u->instance)
  87                 return -ENOTSUP;
  88
  89         n = unit_name_unescape(u->instance);
  90         if (!n)
  91                 return -ENOMEM;
  92
  93         *ret = n;
  94         return 0;
  95 }
  96
  97 static int specifier_filename(char specifier, void *data, void *userdata, char **ret) {
  98         Unit *u = userdata;
  99         char *n;
 100
 101         assert(u);
 102
 103         if (u->instance)
 104                 n = unit_name_path_unescape(u->instance);
 105         else
 106                 n = unit_name_to_path(u->id);
 107         if (!n)
 108                 return -ENOMEM;
 109
 110         *ret = n;
 111         return 0;
 112 }
 113
 114 static int specifier_cgroup(char specifier, void *data, void *userdata, char **ret) {
 115         Unit *u = userdata;
 116         char *n;
 117
 118         assert(u);
 119
 120         if (u->cgroup_path)
 121                 n = strdup(u->cgroup_path);
 122         else
 123                 n = unit_default_cgroup_path(u);
 124         if (!n)
 125                 return -ENOMEM;
 126
 127         *ret = n;
 128         return 0;
 129 }
 130
 131 static int specifier_cgroup_root(char specifier, void *data, void *userdata, char **ret) {
 132         Unit *u = userdata;
 133         const char *slice;
 134         char *n;
 135         int r;
 136
 137         assert(u);
 138
 139         slice = unit_slice_name(u);
 140         if (specifier == 'R' || !slice)
 141                 n = strdup(u->manager->cgroup_root);
 142         else {
 143                 _cleanup_free_ char *p = NULL;
 144
 145                 r = cg_slice_to_path(slice, &p);
 146                 if (r < 0)
 147                         return r;
 148
 149                 n = strjoin(u->manager->cgroup_root, "/", p, NULL);
 150                 if (!n)
 151                         return -ENOMEM;
 152         }
 153
 154         *ret = n;
 155         return 0;
 156 }
 157
 158 static int specifier_runtime(char specifier, void *data, void *userdata, char **ret) {
 159         Unit *u = userdata;
 160         const char *e;
 161         char *n = NULL;
 162
 163         assert(u);
 164
 165         if (u->manager->running_as == SYSTEMD_SYSTEM)
 166                 e = "/run";
 167         else {
 168                 e = getenv("XDG_RUNTIME_DIR");
 169                 if (!e)
 170                         return -ENOTSUP;
 171         }
 172
 173         n = strdup(e);
 174         if (!n)
 175                 return -ENOMEM;
 176
 177         *ret = n;
 178         return 0;
 179 }
 180
 181 static int specifier_user_name(char specifier, void *data, void *userdata, char **ret) {
 182         char *printed = NULL;
 183         Unit *u = userdata;
 184         ExecContext *c;
 185         int r;
 186
 187         assert(u);
 188
 189         c = unit_get_exec_context(u);
 190         if (!c)
 191                 return -ENOTSUP;
 192
 193         if (u->manager->running_as == SYSTEMD_SYSTEM) {
 194
 195                 /* We cannot use NSS from PID 1, hence try to make the
 196                  * best of it in that case, and fail if we can't help
 197                  * it */
 198
 199                 if (!c->user || streq(c->user, "root") || streq(c->user, "0"))
 200                         printed = strdup(specifier == 'u' ? "root" : "0");
 201                 else {
 202                         if (specifier == 'u')
 203                                 printed = strdup(c->user);
 204                         else {
 205                                 uid_t uid;
 206
 207                                 r = parse_uid(c->user, &uid);
 208                                 if (r < 0)
 209                                         return -ENODATA;
 210
 211                                 asprintf(&printed, UID_FMT, uid);
 212                         }
 213                 }
 214
 215         } else {
 216                 _cleanup_free_ char *tmp = NULL;
 217                 const char *username = NULL;
 218                 uid_t uid;
 219
 220                 if (c->user)
 221                         username = c->user;
 222                 else
 223                         /* get USER env from env or our own uid */
 224                         username = tmp = getusername_malloc();
 225
 226                 /* fish username from passwd */
 227                 r = get_user_creds(&username, &uid, NULL, NULL, NULL);
 228                 if (r < 0)
 229                         return r;
 230
 231                 if (specifier == 'u')
 232                         printed = strdup(username);
 233                 else
 234                         asprintf(&printed, UID_FMT, uid);
 235         }
 236
 237         if (!printed)
 238                 return -ENOMEM;
 239
 240         *ret = printed;
 241         return 0;
 242 }
 243
 244 static int specifier_user_home(char specifier, void *data, void *userdata, char **ret) {
 245         Unit *u = userdata;
 246         ExecContext *c;
 247         char *n;
 248         int r;
 249
 250         assert(u);
 251
 252         c = unit_get_exec_context(u);
 253         if (!c)
 254                 return -ENOTSUP;
 255
 256         if (u->manager->running_as == SYSTEMD_SYSTEM) {
 257
 258                 /* We cannot use NSS from PID 1, hence try to make the
 259                  * best of it if we can, but fail if we can't */
 260
 261                 if (!c->user || streq(c->user, "root") || streq(c->user, "0"))
 262                         n = strdup("/root");
 263                 else
 264                         return -ENOTSUP;
 265
 266         } else {
 267
 268                 /* return HOME if set, otherwise from passwd */
 269                 if (!c || !c->user) {
 270                         r = get_home_dir(&n);
 271                         if (r < 0)
 272                                 return r;
 273                 } else {
 274                         const char *username, *home;
 275
 276                         username = c->user;
 277                         r = get_user_creds(&username, NULL, NULL, &home, NULL);
 278                         if (r < 0)
 279                                 return r;
 280
 281                         n = strdup(home);
 282                 }
 283         }
 284
 285         if (!n)
 286                 return -ENOMEM;
 287
 288         *ret = n;
 289         return 0;
 290 }
 291
 292 static int specifier_user_shell(char specifier, void *data, void *userdata, char **ret) {
 293         Unit *u = userdata;
 294         ExecContext *c;
 295         char *n;
 296         int r;
 297
 298         assert(u);
 299
 300         c = unit_get_exec_context(u);
 301         if (!c)
 302                 return -ENOTSUP;
 303
 304         if (u->manager->running_as == SYSTEMD_SYSTEM) {
 305
 306                 /* We cannot use NSS from PID 1, hence try to make the
 307                  * best of it if we can, but fail if we can't */
 308
 309                 if (!c->user || streq(c->user, "root") || streq(c->user, "0"))
 310                         n = strdup("/bin/sh");
 311                 else
 312                         return -ENOTSUP;
 313
 314         } else {
 315
 316                 /* return /bin/sh for root, otherwise the value from passwd */
 317                 if (!c->user) {
 318                         r = get_shell(&n);
 319                         if (r < 0)
 320                                 return r;
 321                 } else {
 322                         const char *username, *shell;
 323
 324                         username = c->user;
 325                         r = get_user_creds(&username, NULL, NULL, NULL, &shell);
 326                         if (r < 0)
 327                                 return r;
 328
 329                         n = strdup(shell);
 330                 }
 331         }
 332
 333         if (!n)
 334                 return -ENOMEM;
 335
 336         *ret = n;
 337         return 0;
 338 }
 339
 340 int unit_name_printf(Unit *u, const char* format, char **ret) {
 341
 342         /*
 343          * This will use the passed string as format string and
 344          * replace the following specifiers:
 345          *
 346          * %n: the full id of the unit                 (foo@bar.waldo)
 347          * %N: the id of the unit without the suffix   (foo@bar)
 348          * %p: the prefix                              (foo)
 349          * %i: the instance                            (bar)
 350          */
 351
 352         const Specifier table[] = {
 353                 { 'n', specifier_string,              u->id },
 354                 { 'N', specifier_prefix_and_instance, NULL },
 355                 { 'p', specifier_prefix,              NULL },
 356                 { 'i', specifier_string,              u->instance },
 357                 { 0, NULL, NULL }
 358         };
 359
 360         assert(u);
 361         assert(format);
 362         assert(ret);
 363
 364         return specifier_printf(format, table, u, ret);
 365 }
 366
 367 int unit_full_printf(Unit *u, const char *format, char **ret) {
 368
 369         /* This is similar to unit_name_printf() but also supports
 370          * unescaping. Also, adds a couple of additional codes:
 371          *
 372          * %f the instance if set, otherwise the id
 373          * %c cgroup path of unit
 374          * %r where units in this slice are placed in the cgroup tree
 375          * %R the root of this systemd's instance tree
 376          * %t the runtime directory to place sockets in (e.g. "/run" or $XDG_RUNTIME_DIR)
 377          * %U the UID of the configured user or running user
 378          * %u the username of the configured user or running user
 379          * %h the homedir of the configured user or running user
 380          * %s the shell of the configured user or running user
 381          * %m the machine ID of the running system
 382          * %H the host name of the running system
 383          * %b the boot ID of the running system
 384          * %v `uname -r` of the running system
 385          */
 386
 387         const Specifier table[] = {
 388                 { 'n', specifier_string,              u->id },
 389                 { 'N', specifier_prefix_and_instance, NULL },
 390                 { 'p', specifier_prefix,              NULL },
 391                 { 'P', specifier_prefix_unescaped,    NULL },
 392                 { 'i', specifier_string,              u->instance },
 393                 { 'I', specifier_instance_unescaped,  NULL },
 394
 395                 { 'f', specifier_filename,            NULL },
 396                 { 'c', specifier_cgroup,              NULL },
 397                 { 'r', specifier_cgroup_root,         NULL },
 398                 { 'R', specifier_cgroup_root,         NULL },
 399                 { 't', specifier_runtime,             NULL },
 400                 { 'U', specifier_user_name,           NULL },
 401                 { 'u', specifier_user_name,           NULL },
 402                 { 'h', specifier_user_home,           NULL },
 403                 { 's', specifier_user_shell,          NULL },
 404
 405                 { 'm', specifier_machine_id,          NULL },
 406                 { 'H', specifier_host_name,           NULL },
 407                 { 'b', specifier_boot_id,             NULL },
 408                 { 'v', specifier_kernel_release,      NULL },
 409                 {}
 410         };
 411
 412         assert(u);
 413         assert(format);
 414         assert(ret);
 415
 416         return specifier_printf(format, table, u, ret);
 417 }
 418
 419 int unit_full_printf_strv(Unit *u, char **l, char ***ret) {
 420         size_t n;
 421         char **r, **i, **j;
 422         int q;
 423
 424         /* Applies unit_full_printf to every entry in l */
 425
 426         assert(u);
 427
 428         n = strv_length(l);
 429         r = new(char*, n+1);
 430         if (!r)
 431                 return -ENOMEM;
 432
 433         for (i = l, j = r; *i; i++, j++) {
 434                 q = unit_full_printf(u, *i, j);
 435                 if (q < 0)
 436                         goto fail;
 437         }
 438
 439         *j = NULL;
 440         *ret = r;
 441         return 0;
 442
 443 fail:
 444         for (j--; j >= r; j--)
 445                 free(*j);
 446
 447         free(r);
 448         return q;
 449 }