src/core/unit-printf.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2010 Lennart Poettering
   6 ***/
   7
   8 #include "alloc-util.h"
   9 #include "cgroup-util.h"
  10 #include "format-util.h"
  11 #include "macro.h"
  12 #include "specifier.h"
  13 #include "string-util.h"
  14 #include "strv.h"
  15 #include "unit-name.h"
  16 #include "unit-printf.h"
  17 #include "unit.h"
  18 #include "user-util.h"
  19
  20 static int specifier_prefix_and_instance(char specifier, void *data, void *userdata, char **ret) {
  21         Unit *u = userdata;
  22
  23         assert(u);
  24
  25         return unit_name_to_prefix_and_instance(u->id, ret);
  26 }
  27
  28 static int specifier_prefix(char specifier, void *data, void *userdata, char **ret) {
  29         Unit *u = userdata;
  30
  31         assert(u);
  32
  33         return unit_name_to_prefix(u->id, ret);
  34 }
  35
  36 static int specifier_prefix_unescaped(char specifier, void *data, void *userdata, char **ret) {
  37         _cleanup_free_ char *p = NULL;
  38         Unit *u = userdata;
  39         int r;
  40
  41         assert(u);
  42
  43         r = unit_name_to_prefix(u->id, &p);
  44         if (r < 0)
  45                 return r;
  46
  47         return unit_name_unescape(p, ret);
  48 }
  49
  50 static int specifier_instance_unescaped(char specifier, void *data, void *userdata, char **ret) {
  51         Unit *u = userdata;
  52
  53         assert(u);
  54
  55         return unit_name_unescape(strempty(u->instance), ret);
  56 }
  57
  58 static int specifier_filename(char specifier, void *data, void *userdata, char **ret) {
  59         Unit *u = userdata;
  60
  61         assert(u);
  62
  63         if (u->instance)
  64                 return unit_name_path_unescape(u->instance, ret);
  65         else
  66                 return unit_name_to_path(u->id, ret);
  67 }
  68
  69 static void bad_specifier(Unit *u, char specifier) {
  70         log_unit_warning(u, "Specifier '%%%c' used in unit configuration, which is deprecated. Please update your unit file, as it does not work as intended.", specifier);
  71 }
  72
  73 static int specifier_cgroup(char specifier, void *data, void *userdata, char **ret) {
  74         Unit *u = userdata;
  75         char *n;
  76
  77         assert(u);
  78
  79         bad_specifier(u, specifier);
  80
  81         if (u->cgroup_path)
  82                 n = strdup(u->cgroup_path);
  83         else
  84                 n = unit_default_cgroup_path(u);
  85         if (!n)
  86                 return -ENOMEM;
  87
  88         *ret = n;
  89         return 0;
  90 }
  91
  92 static int specifier_cgroup_root(char specifier, void *data, void *userdata, char **ret) {
  93         Unit *u = userdata;
  94         char *n;
  95
  96         assert(u);
  97
  98         bad_specifier(u, specifier);
  99
 100         n = strdup(u->manager->cgroup_root);
 101         if (!n)
 102                 return -ENOMEM;
 103
 104         *ret = n;
 105         return 0;
 106 }
 107
 108 static int specifier_cgroup_slice(char specifier, void *data, void *userdata, char **ret) {
 109         Unit *u = userdata;
 110         char *n;
 111
 112         assert(u);
 113
 114         bad_specifier(u, specifier);
 115
 116         if (UNIT_ISSET(u->slice)) {
 117                 Unit *slice;
 118
 119                 slice = UNIT_DEREF(u->slice);
 120
 121                 if (slice->cgroup_path)
 122                         n = strdup(slice->cgroup_path);
 123                 else
 124                         n = unit_default_cgroup_path(slice);
 125         } else
 126                 n = strdup(u->manager->cgroup_root);
 127         if (!n)
 128                 return -ENOMEM;
 129
 130         *ret = n;
 131         return 0;
 132 }
 133
 134 static int specifier_special_directory(char specifier, void *data, void *userdata, char **ret) {
 135         Unit *u = userdata;
 136         char *n = NULL;
 137
 138         assert(u);
 139
 140         n = strdup(u->manager->prefix[PTR_TO_UINT(data)]);
 141         if (!n)
 142                 return -ENOMEM;
 143
 144         *ret = n;
 145         return 0;
 146 }
 147
 148 int unit_name_printf(Unit *u, const char* format, char **ret) {
 149
 150         /*
 151          * This will use the passed string as format string and replace the following specifiers (which should all be
 152          * safe for inclusion in unit names):
 153          *
 154          * %n: the full id of the unit                 (foo@bar.waldo)
 155          * %N: the id of the unit without the suffix   (foo@bar)
 156          * %p: the prefix                              (foo)
 157          * %i: the instance                            (bar)
 158          *
 159          * %U: the UID of the running user
 160          * %u: the username of the running user
 161          *
 162          * %m: the machine ID of the running system
 163          * %H: the host name of the running system
 164          * %b: the boot ID of the running system
 165          */
 166
 167         const Specifier table[] = {
 168                 { 'n', specifier_string,              u->id },
 169                 { 'N', specifier_prefix_and_instance, NULL },
 170                 { 'p', specifier_prefix,              NULL },
 171                 { 'i', specifier_string,              u->instance },
 172
 173                 { 'U', specifier_user_id,             NULL },
 174                 { 'u', specifier_user_name,           NULL },
 175
 176                 { 'm', specifier_machine_id,          NULL },
 177                 { 'H', specifier_host_name,           NULL },
 178                 { 'b', specifier_boot_id,             NULL },
 179                 {}
 180         };
 181
 182         assert(u);
 183         assert(format);
 184         assert(ret);
 185
 186         return specifier_printf(format, table, u, ret);
 187 }
 188
 189 int unit_full_printf(Unit *u, const char *format, char **ret) {
 190
 191         /* This is similar to unit_name_printf() but also supports unescaping. Also, adds a couple of additional codes
 192          * (which are likely not suitable for unescaped inclusion in unit names):
 193          *
 194          * %f: the unescaped instance if set, otherwise the id unescaped as path
 195          *
 196          * %c: cgroup path of unit (deprecated)
 197          * %r: where units in this slice are placed in the cgroup tree (deprecated)
 198          * %R: the root of this systemd's instance tree (deprecated)
 199          *
 200          * %t: the runtime directory root (e.g. /run or $XDG_RUNTIME_DIR)
 201          * %S: the state directory root (e.g. /var/lib or $XDG_CONFIG_HOME)
 202          * %C: the cache directory root (e.g. /var/cache or $XDG_CACHE_HOME)
 203          * %L: the log directory root (e.g. /var/log or $XDG_CONFIG_HOME/log)
 204          *
 205          * %h: the homedir of the running user
 206          * %s: the shell of the running user
 207          *
 208          * %v: `uname -r` of the running system
 209          *
 210          * NOTICE: When you add new entries here, please be careful: specifiers which depend on settings of the unit
 211          * file itself are broken by design, as they would resolve differently depending on whether they are used
 212          * before or after the relevant configuration setting. Hence: don't add them.
 213          */
 214
 215         const Specifier table[] = {
 216                 { 'n', specifier_string,              u->id },
 217                 { 'N', specifier_prefix_and_instance, NULL },
 218                 { 'p', specifier_prefix,              NULL },
 219                 { 'P', specifier_prefix_unescaped,    NULL },
 220                 { 'i', specifier_string,              u->instance },
 221                 { 'I', specifier_instance_unescaped,  NULL },
 222
 223                 { 'f', specifier_filename,            NULL },
 224                 { 'c', specifier_cgroup,              NULL },
 225                 { 'r', specifier_cgroup_slice,        NULL },
 226                 { 'R', specifier_cgroup_root,         NULL },
 227                 { 't', specifier_special_directory,   UINT_TO_PTR(EXEC_DIRECTORY_RUNTIME) },
 228                 { 'S', specifier_special_directory,   UINT_TO_PTR(EXEC_DIRECTORY_STATE) },
 229                 { 'C', specifier_special_directory,   UINT_TO_PTR(EXEC_DIRECTORY_CACHE) },
 230                 { 'L', specifier_special_directory,   UINT_TO_PTR(EXEC_DIRECTORY_LOGS) },
 231
 232                 { 'U', specifier_user_id,             NULL },
 233                 { 'u', specifier_user_name,           NULL },
 234                 { 'h', specifier_user_home,           NULL },
 235                 { 's', specifier_user_shell,          NULL },
 236
 237                 { 'm', specifier_machine_id,          NULL },
 238                 { 'H', specifier_host_name,           NULL },
 239                 { 'b', specifier_boot_id,             NULL },
 240                 { 'v', specifier_kernel_release,      NULL },
 241                 {}
 242         };
 243
 244         assert(u);
 245         assert(format);
 246         assert(ret);
 247
 248         return specifier_printf(format, table, u, ret);
 249 }
 250
 251 int unit_full_printf_strv(Unit *u, char **l, char ***ret) {
 252         size_t n;
 253         char **r, **i, **j;
 254         int q;
 255
 256         /* Applies unit_full_printf to every entry in l */
 257
 258         assert(u);
 259
 260         n = strv_length(l);
 261         r = new(char*, n+1);
 262         if (!r)
 263                 return -ENOMEM;
 264
 265         for (i = l, j = r; *i; i++, j++) {
 266                 q = unit_full_printf(u, *i, j);
 267                 if (q < 0)
 268                         goto fail;
 269         }
 270
 271         *j = NULL;
 272         *ret = r;
 273         return 0;
 274
 275 fail:
 276         for (j--; j >= r; j--)
 277                 free(*j);
 278
 279         free(r);
 280         return q;
 281 }