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_last_component(char specifier, void *data, void *userdata, char **ret) {
  59         Unit *u = userdata;
  60         _cleanup_free_ char *prefix = NULL;
  61         char *dash;
  62         int r;
  63
  64         assert(u);
  65
  66         r = unit_name_to_prefix(u->id, &prefix);
  67         if (r < 0)
  68                 return r;
  69
  70         dash = strrchr(prefix, '-');
  71         if (dash)
  72                 return specifier_string(specifier, dash + 1, userdata, ret);
  73
  74         *ret = TAKE_PTR(prefix);
  75         return 0;
  76 }
  77
  78 static int specifier_last_component_unescaped(char specifier, void *data, void *userdata, char **ret) {
  79         _cleanup_free_ char *p = NULL;
  80         int r;
  81
  82         r = specifier_last_component(specifier, data, userdata, &p);
  83         if (r < 0)
  84                 return r;
  85
  86         return unit_name_unescape(p, ret);
  87 }
  88
  89 static int specifier_filename(char specifier, void *data, void *userdata, char **ret) {
  90         Unit *u = userdata;
  91
  92         assert(u);
  93
  94         if (u->instance)
  95                 return unit_name_path_unescape(u->instance, ret);
  96         else
  97                 return unit_name_to_path(u->id, ret);
  98 }
  99
 100 static void bad_specifier(Unit *u, char specifier) {
 101         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);
 102 }
 103
 104 static int specifier_cgroup(char specifier, void *data, void *userdata, char **ret) {
 105         Unit *u = userdata;
 106         char *n;
 107
 108         assert(u);
 109
 110         bad_specifier(u, specifier);
 111
 112         if (u->cgroup_path)
 113                 n = strdup(u->cgroup_path);
 114         else
 115                 n = unit_default_cgroup_path(u);
 116         if (!n)
 117                 return -ENOMEM;
 118
 119         *ret = n;
 120         return 0;
 121 }
 122
 123 static int specifier_cgroup_root(char specifier, void *data, void *userdata, char **ret) {
 124         Unit *u = userdata;
 125         char *n;
 126
 127         assert(u);
 128
 129         bad_specifier(u, specifier);
 130
 131         n = strdup(u->manager->cgroup_root);
 132         if (!n)
 133                 return -ENOMEM;
 134
 135         *ret = n;
 136         return 0;
 137 }
 138
 139 static int specifier_cgroup_slice(char specifier, void *data, void *userdata, char **ret) {
 140         Unit *u = userdata;
 141         char *n;
 142
 143         assert(u);
 144
 145         bad_specifier(u, specifier);
 146
 147         if (UNIT_ISSET(u->slice)) {
 148                 Unit *slice;
 149
 150                 slice = UNIT_DEREF(u->slice);
 151
 152                 if (slice->cgroup_path)
 153                         n = strdup(slice->cgroup_path);
 154                 else
 155                         n = unit_default_cgroup_path(slice);
 156         } else
 157                 n = strdup(u->manager->cgroup_root);
 158         if (!n)
 159                 return -ENOMEM;
 160
 161         *ret = n;
 162         return 0;
 163 }
 164
 165 static int specifier_special_directory(char specifier, void *data, void *userdata, char **ret) {
 166         Unit *u = userdata;
 167         char *n = NULL;
 168
 169         assert(u);
 170
 171         n = strdup(u->manager->prefix[PTR_TO_UINT(data)]);
 172         if (!n)
 173                 return -ENOMEM;
 174
 175         *ret = n;
 176         return 0;
 177 }
 178
 179 int unit_name_printf(Unit *u, const char* format, char **ret) {
 180
 181         /*
 182          * This will use the passed string as format string and replace the following specifiers (which should all be
 183          * safe for inclusion in unit names):
 184          *
 185          * %n: the full id of the unit                 (foo@bar.waldo)
 186          * %N: the id of the unit without the suffix   (foo@bar)
 187          * %p: the prefix                              (foo)
 188          * %i: the instance                            (bar)
 189          *
 190          * %U: the UID of the running user
 191          * %u: the username of the running user
 192          *
 193          * %m: the machine ID of the running system
 194          * %H: the host name of the running system
 195          * %b: the boot ID of the running system
 196          */
 197
 198         const Specifier table[] = {
 199                 { 'n', specifier_string,              u->id },
 200                 { 'N', specifier_prefix_and_instance, NULL },
 201                 { 'p', specifier_prefix,              NULL },
 202                 { 'i', specifier_string,              u->instance },
 203
 204                 { 'U', specifier_user_id,             NULL },
 205                 { 'u', specifier_user_name,           NULL },
 206
 207                 { 'm', specifier_machine_id,          NULL },
 208                 { 'H', specifier_host_name,           NULL },
 209                 { 'b', specifier_boot_id,             NULL },
 210                 {}
 211         };
 212
 213         assert(u);
 214         assert(format);
 215         assert(ret);
 216
 217         return specifier_printf(format, table, u, ret);
 218 }
 219
 220 int unit_full_printf(Unit *u, const char *format, char **ret) {
 221
 222         /* This is similar to unit_name_printf() but also supports unescaping. Also, adds a couple of additional codes
 223          * (which are likely not suitable for unescaped inclusion in unit names):
 224          *
 225          * %f: the unescaped instance if set, otherwise the id unescaped as path
 226          *
 227          * %c: cgroup path of unit (deprecated)
 228          * %r: where units in this slice are placed in the cgroup tree (deprecated)
 229          * %R: the root of this systemd's instance tree (deprecated)
 230          *
 231          * %t: the runtime directory root (e.g. /run or $XDG_RUNTIME_DIR)
 232          * %S: the state directory root (e.g. /var/lib or $XDG_CONFIG_HOME)
 233          * %C: the cache directory root (e.g. /var/cache or $XDG_CACHE_HOME)
 234          * %L: the log directory root (e.g. /var/log or $XDG_CONFIG_HOME/log)
 235          *
 236          * %h: the homedir of the running user
 237          * %s: the shell of the running user
 238          *
 239          * %v: `uname -r` of the running system
 240          *
 241          * NOTICE: When you add new entries here, please be careful: specifiers which depend on settings of the unit
 242          * file itself are broken by design, as they would resolve differently depending on whether they are used
 243          * before or after the relevant configuration setting. Hence: don't add them.
 244          */
 245
 246         const Specifier table[] = {
 247                 { 'n', specifier_string,                   u->id },
 248                 { 'N', specifier_prefix_and_instance,      NULL },
 249                 { 'p', specifier_prefix,                   NULL },
 250                 { 'P', specifier_prefix_unescaped,         NULL },
 251                 { 'i', specifier_string,                   u->instance },
 252                 { 'I', specifier_instance_unescaped,       NULL },
 253                 { 'j', specifier_last_component,           NULL },
 254                 { 'J', specifier_last_component_unescaped, NULL },
 255
 256                 { 'f', specifier_filename,                 NULL },
 257                 { 'c', specifier_cgroup,                   NULL },
 258                 { 'r', specifier_cgroup_slice,             NULL },
 259                 { 'R', specifier_cgroup_root,              NULL },
 260                 { 't', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_RUNTIME) },
 261                 { 'S', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_STATE) },
 262                 { 'C', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CACHE) },
 263                 { 'L', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_LOGS) },
 264
 265                 { 'U', specifier_user_id,                  NULL },
 266                 { 'u', specifier_user_name,                NULL },
 267                 { 'h', specifier_user_home,                NULL },
 268                 { 's', specifier_user_shell,               NULL },
 269
 270                 { 'm', specifier_machine_id,               NULL },
 271                 { 'H', specifier_host_name,                NULL },
 272                 { 'b', specifier_boot_id,                  NULL },
 273                 { 'v', specifier_kernel_release,           NULL },
 274                 {}
 275         };
 276
 277         assert(u);
 278         assert(format);
 279         assert(ret);
 280
 281         return specifier_printf(format, table, u, ret);
 282 }
 283
 284 int unit_full_printf_strv(Unit *u, char **l, char ***ret) {
 285         size_t n;
 286         char **r, **i, **j;
 287         int q;
 288
 289         /* Applies unit_full_printf to every entry in l */
 290
 291         assert(u);
 292
 293         n = strv_length(l);
 294         r = new(char*, n+1);
 295         if (!r)
 296                 return -ENOMEM;
 297
 298         for (i = l, j = r; *i; i++, j++) {
 299                 q = unit_full_printf(u, *i, j);
 300                 if (q < 0)
 301                         goto fail;
 302         }
 303
 304         *j = NULL;
 305         *ret = r;
 306         return 0;
 307
 308 fail:
 309         for (j--; j >= r; j--)
 310                 free(*j);
 311
 312         free(r);
 313         return q;
 314 }