src/core/unit-printf.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include "alloc-util.h"
   4 #include "cgroup-util.h"
   5 #include "format-util.h"
   6 #include "macro.h"
   7 #include "specifier.h"
   8 #include "string-util.h"
   9 #include "strv.h"
  10 #include "unit-name.h"
  11 #include "unit-printf.h"
  12 #include "unit.h"
  13 #include "user-util.h"
  14
  15 static int specifier_prefix_and_instance(char specifier, const void *data, const void *userdata, char **ret) {
  16         const Unit *u = userdata;
  17
  18         assert(u);
  19
  20         return unit_name_to_prefix_and_instance(u->id, ret);
  21 }
  22
  23 static int specifier_prefix(char specifier, const void *data, const void *userdata, char **ret) {
  24         const Unit *u = userdata;
  25
  26         assert(u);
  27
  28         return unit_name_to_prefix(u->id, ret);
  29 }
  30
  31 static int specifier_prefix_unescaped(char specifier, const void *data, const void *userdata, char **ret) {
  32         _cleanup_free_ char *p = NULL;
  33         const Unit *u = userdata;
  34         int r;
  35
  36         assert(u);
  37
  38         r = unit_name_to_prefix(u->id, &p);
  39         if (r < 0)
  40                 return r;
  41
  42         return unit_name_unescape(p, ret);
  43 }
  44
  45 static int specifier_instance_unescaped(char specifier, const void *data, const void *userdata, char **ret) {
  46         const Unit *u = userdata;
  47
  48         assert(u);
  49
  50         return unit_name_unescape(strempty(u->instance), ret);
  51 }
  52
  53 static int specifier_last_component(char specifier, const void *data, const void *userdata, char **ret) {
  54         const Unit *u = userdata;
  55         _cleanup_free_ char *prefix = NULL;
  56         char *dash;
  57         int r;
  58
  59         assert(u);
  60
  61         r = unit_name_to_prefix(u->id, &prefix);
  62         if (r < 0)
  63                 return r;
  64
  65         dash = strrchr(prefix, '-');
  66         if (dash)
  67                 return specifier_string(specifier, dash + 1, userdata, ret);
  68
  69         *ret = TAKE_PTR(prefix);
  70         return 0;
  71 }
  72
  73 static int specifier_last_component_unescaped(char specifier, const void *data, const void *userdata, char **ret) {
  74         _cleanup_free_ char *p = NULL;
  75         int r;
  76
  77         r = specifier_last_component(specifier, data, userdata, &p);
  78         if (r < 0)
  79                 return r;
  80
  81         return unit_name_unescape(p, ret);
  82 }
  83
  84 static int specifier_filename(char specifier, const void *data, const void *userdata, char **ret) {
  85         const Unit *u = userdata;
  86
  87         assert(u);
  88
  89         if (u->instance)
  90                 return unit_name_path_unescape(u->instance, ret);
  91         else
  92                 return unit_name_to_path(u->id, ret);
  93 }
  94
  95 static void bad_specifier(const Unit *u, char specifier) {
  96         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);
  97 }
  98
  99 static int specifier_cgroup(char specifier, const void *data, const void *userdata, char **ret) {
 100         const Unit *u = userdata;
 101         char *n;
 102
 103         assert(u);
 104
 105         bad_specifier(u, specifier);
 106
 107         if (u->cgroup_path)
 108                 n = strdup(u->cgroup_path);
 109         else
 110                 n = unit_default_cgroup_path(u);
 111         if (!n)
 112                 return -ENOMEM;
 113
 114         *ret = n;
 115         return 0;
 116 }
 117
 118 static int specifier_cgroup_root(char specifier, const void *data, const void *userdata, char **ret) {
 119         const Unit *u = userdata;
 120         char *n;
 121
 122         assert(u);
 123
 124         bad_specifier(u, specifier);
 125
 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_cgroup_slice(char specifier, const void *data, const void *userdata, char **ret) {
 135         const Unit *u = userdata;
 136         char *n;
 137
 138         assert(u);
 139
 140         bad_specifier(u, specifier);
 141
 142         if (UNIT_ISSET(u->slice)) {
 143                 const Unit *slice;
 144
 145                 slice = UNIT_DEREF(u->slice);
 146
 147                 if (slice->cgroup_path)
 148                         n = strdup(slice->cgroup_path);
 149                 else
 150                         n = unit_default_cgroup_path(slice);
 151         } else
 152                 n = strdup(u->manager->cgroup_root);
 153         if (!n)
 154                 return -ENOMEM;
 155
 156         *ret = n;
 157         return 0;
 158 }
 159
 160 static int specifier_special_directory(char specifier, const void *data, const void *userdata, char **ret) {
 161         const Unit *u = userdata;
 162         char *n = NULL;
 163
 164         assert(u);
 165
 166         n = strdup(u->manager->prefix[PTR_TO_UINT(data)]);
 167         if (!n)
 168                 return -ENOMEM;
 169
 170         *ret = n;
 171         return 0;
 172 }
 173
 174 int unit_name_printf(const Unit *u, const char* format, char **ret) {
 175
 176         /*
 177          * This will use the passed string as format string and replace the following specifiers (which should all be
 178          * safe for inclusion in unit names):
 179          *
 180          * %n: the full id of the unit                 (foo@bar.waldo)
 181          * %N: the id of the unit without the suffix   (foo@bar)
 182          * %p: the prefix                              (foo)
 183          * %i: the instance                            (bar)
 184          *
 185          * %U: the UID of the running user
 186          * %u: the username of the running user
 187          *
 188          * %m: the machine ID of the running system
 189          * %H: the hostname of the running system
 190          * %b: the boot ID of the running system
 191          */
 192
 193         const Specifier table[] = {
 194                 { 'n', specifier_string,              u->id },
 195                 { 'N', specifier_prefix_and_instance, NULL },
 196                 { 'p', specifier_prefix,              NULL },
 197                 { 'i', specifier_string,              u->instance },
 198                 { 'j', specifier_last_component,      NULL },
 199
 200                 { 'g', specifier_group_name,          NULL },
 201                 { 'G', specifier_group_id,            NULL },
 202                 { 'U', specifier_user_id,             NULL },
 203                 { 'u', specifier_user_name,           NULL },
 204
 205                 { 'm', specifier_machine_id,          NULL },
 206                 { 'H', specifier_host_name,           NULL },
 207                 { 'b', specifier_boot_id,             NULL },
 208                 {}
 209         };
 210
 211         assert(u);
 212         assert(format);
 213         assert(ret);
 214
 215         return specifier_printf(format, table, u, ret);
 216 }
 217
 218 int unit_full_printf(const Unit *u, const char *format, char **ret) {
 219         /* This is similar to unit_name_printf() but also supports unescaping. Also, adds a couple of additional codes
 220          * (which are likely not suitable for unescaped inclusion in unit names):
 221          *
 222          * %f: the unescaped instance if set, otherwise the id unescaped as path
 223          *
 224          * %c: cgroup path of unit (deprecated)
 225          * %r: where units in this slice are placed in the cgroup tree (deprecated)
 226          * %R: the root of this systemd's instance tree (deprecated)
 227          *
 228          * %t: the runtime directory root (e.g. /run or $XDG_RUNTIME_DIR)
 229          * %S: the state directory root (e.g. /var/lib or $XDG_CONFIG_HOME)
 230          * %C: the cache directory root (e.g. /var/cache or $XDG_CACHE_HOME)
 231          * %L: the log directory root (e.g. /var/log or $XDG_CONFIG_HOME/log)
 232          * %E: the configuration directory root (e.g. /etc or $XDG_CONFIG_HOME)
 233          * %T: the temporary directory (e.g. /tmp, or $TMPDIR, $TEMP, $TMP)
 234          * %V: the temporary directory for large, persistent stuff (e.g. /var/tmp, or $TMPDIR, $TEMP, $TMP)
 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         assert(u);
 247         assert(format);
 248         assert(ret);
 249
 250         const Specifier table[] = {
 251                 { 'n', specifier_string,                   u->id },
 252                 { 'N', specifier_prefix_and_instance,      NULL },
 253                 { 'p', specifier_prefix,                   NULL },
 254                 { 'P', specifier_prefix_unescaped,         NULL },
 255                 { 'i', specifier_string,                   u->instance },
 256                 { 'I', specifier_instance_unescaped,       NULL },
 257                 { 'j', specifier_last_component,           NULL },
 258                 { 'J', specifier_last_component_unescaped, NULL },
 259
 260                 { 'f', specifier_filename,                 NULL },
 261                 { 'c', specifier_cgroup,                   NULL },
 262                 { 'r', specifier_cgroup_slice,             NULL },
 263                 { 'R', specifier_cgroup_root,              NULL },
 264
 265                 { 't', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_RUNTIME) },
 266                 { 'S', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_STATE) },
 267                 { 'C', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CACHE) },
 268                 { 'L', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_LOGS) },
 269                 { 'E', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CONFIGURATION) },
 270                 { 'T', specifier_tmp_dir,                  NULL },
 271                 { 'V', specifier_var_tmp_dir,              NULL },
 272
 273                 { 'g', specifier_group_name,               NULL },
 274                 { 'G', specifier_group_id,                 NULL },
 275                 { 'U', specifier_user_id,                  NULL },
 276                 { 'u', specifier_user_name,                NULL },
 277                 { 'h', specifier_user_home,                NULL },
 278                 { 's', specifier_user_shell,               NULL },
 279
 280                 { 'm', specifier_machine_id,               NULL },
 281                 { 'H', specifier_host_name,                NULL },
 282                 { 'b', specifier_boot_id,                  NULL },
 283                 { 'v', specifier_kernel_release,           NULL },
 284                 {}
 285         };
 286
 287         return specifier_printf(format, table, u, ret);
 288 }