src/core/unit-printf.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   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 char *root, const void *userdata, char **ret) {
  16         const Unit *u = ASSERT_PTR(userdata);
  17
  18         return unit_name_to_prefix_and_instance(u->id, ret);
  19 }
  20
  21 static int specifier_prefix(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  22         const Unit *u = ASSERT_PTR(userdata);
  23
  24         return unit_name_to_prefix(u->id, ret);
  25 }
  26
  27 static int specifier_prefix_unescaped(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  28         _cleanup_free_ char *p = NULL;
  29         const Unit *u = ASSERT_PTR(userdata);
  30         int r;
  31
  32         r = unit_name_to_prefix(u->id, &p);
  33         if (r < 0)
  34                 return r;
  35
  36         return unit_name_unescape(p, ret);
  37 }
  38
  39 static int specifier_instance_unescaped(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  40         const Unit *u = ASSERT_PTR(userdata);
  41
  42         return unit_name_unescape(strempty(u->instance), ret);
  43 }
  44
  45 static int specifier_last_component(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  46         const Unit *u = ASSERT_PTR(userdata);
  47         _cleanup_free_ char *prefix = NULL;
  48         char *dash;
  49         int r;
  50
  51         r = unit_name_to_prefix(u->id, &prefix);
  52         if (r < 0)
  53                 return r;
  54
  55         dash = strrchr(prefix, '-');
  56         if (dash)
  57                 return specifier_string(specifier, dash + 1, root, userdata, ret);
  58
  59         *ret = TAKE_PTR(prefix);
  60         return 0;
  61 }
  62
  63 static int specifier_last_component_unescaped(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  64         _cleanup_free_ char *p = NULL;
  65         int r;
  66
  67         r = specifier_last_component(specifier, data, root, userdata, &p);
  68         if (r < 0)
  69                 return r;
  70
  71         return unit_name_unescape(p, ret);
  72 }
  73
  74 static int specifier_filename(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  75         const Unit *u = ASSERT_PTR(userdata);
  76
  77         if (u->instance)
  78                 return unit_name_path_unescape(u->instance, ret);
  79         else
  80                 return unit_name_to_path(u->id, ret);
  81 }
  82
  83 static void bad_specifier(const Unit *u, char specifier) {
  84         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);
  85 }
  86
  87 static int specifier_cgroup(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  88         const Unit *u = ASSERT_PTR(userdata);
  89
  90         bad_specifier(u, specifier);
  91
  92         if (u->cgroup_path) {
  93                 char *n;
  94
  95                 n = strdup(u->cgroup_path);
  96                 if (!n)
  97                         return -ENOMEM;
  98
  99                 *ret = n;
 100                 return 0;
 101         }
 102
 103         return unit_default_cgroup_path(u, ret);
 104 }
 105
 106 static int specifier_cgroup_root(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 107         const Unit *u = ASSERT_PTR(userdata);
 108         char *n;
 109
 110         bad_specifier(u, specifier);
 111
 112         n = strdup(u->manager->cgroup_root);
 113         if (!n)
 114                 return -ENOMEM;
 115
 116         *ret = n;
 117         return 0;
 118 }
 119
 120 static int specifier_cgroup_slice(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 121         const Unit *u = ASSERT_PTR(userdata), *slice;
 122         char *n;
 123
 124         bad_specifier(u, specifier);
 125
 126         slice = UNIT_GET_SLICE(u);
 127         if (slice) {
 128                 if (slice->cgroup_path)
 129                         n = strdup(slice->cgroup_path);
 130                 else
 131                         return unit_default_cgroup_path(slice, ret);
 132         } else
 133                 n = strdup(u->manager->cgroup_root);
 134         if (!n)
 135                 return -ENOMEM;
 136
 137         *ret = n;
 138         return 0;
 139 }
 140
 141 static int specifier_special_directory(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 142         const Unit *u = ASSERT_PTR(userdata);
 143         char *n;
 144
 145         n = strdup(u->manager->prefix[PTR_TO_UINT(data)]);
 146         if (!n)
 147                 return -ENOMEM;
 148
 149         *ret = n;
 150         return 0;
 151 }
 152
 153 static int specifier_credentials_dir(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 154         const Unit *u = ASSERT_PTR(userdata);
 155         char *d;
 156
 157         assert(ret);
 158
 159         d = strjoin(u->manager->prefix[EXEC_DIRECTORY_RUNTIME], "/credentials/", u->id);
 160         if (!d)
 161                 return -ENOMEM;
 162
 163         *ret = d;
 164         return 0;
 165 }
 166
 167 int unit_name_printf(const Unit *u, const char* format, char **ret) {
 168         /*
 169          * This will use the passed string as format string and replace the following specifiers (which should all be
 170          * safe for inclusion in unit names):
 171          *
 172          * %n: the full id of the unit                 (foo-aaa@bar.waldo)
 173          * %N: the id of the unit without the suffix   (foo-aaa@bar)
 174          * %p: the prefix                              (foo-aaa)
 175          * %i: the instance                            (bar)
 176          * %j: the last component of the prefix        (aaa)
 177          */
 178
 179         const Specifier table[] = {
 180                 { 'i', specifier_string,              u->instance },
 181                 { 'j', specifier_last_component,      NULL },
 182                 { 'n', specifier_string,              u->id },
 183                 { 'N', specifier_prefix_and_instance, NULL },
 184                 { 'p', specifier_prefix,              NULL },
 185
 186                 COMMON_SYSTEM_SPECIFIERS,
 187
 188                 COMMON_CREDS_SPECIFIERS(u->manager->runtime_scope),
 189                 {}
 190         };
 191
 192         assert(u);
 193         assert(format);
 194         assert(ret);
 195
 196         return specifier_printf(format, UNIT_NAME_MAX, table, NULL, u, ret);
 197 }
 198
 199 int unit_full_printf_full(const Unit *u, const char *format, size_t max_length, char **ret) {
 200         /* This is similar to unit_name_printf() but also supports unescaping. Also, adds a couple of
 201          * additional codes (which are likely not suitable for unescaped inclusion in unit names):
 202          *
 203          * %f: the unescaped instance if set, otherwise the id unescaped as path
 204          *
 205          * %c: cgroup path of unit (deprecated)
 206          * %r: where units in this slice are placed in the cgroup tree (deprecated)
 207          * %R: the root of this systemd's instance tree (deprecated)
 208          *
 209          * %C: the cache directory root (e.g. /var/cache or $XDG_CACHE_HOME)
 210          * %d: the credentials directory ($CREDENTIALS_DIRECTORY)
 211          * %E: the configuration directory root (e.g. /etc or $XDG_CONFIG_HOME)
 212          * %L: the log directory root (e.g. /var/log or $XDG_STATE_HOME/log)
 213          * %S: the state directory root (e.g. /var/lib or $XDG_STATE_HOME)
 214          * %t: the runtime directory root (e.g. /run or $XDG_RUNTIME_DIR)
 215          *
 216          * %h: the homedir of the running user
 217          * %s: the shell of the running user
 218          *
 219          * NOTICE: When you add new entries here, please be careful: specifiers which depend on settings of
 220          * the unit file itself are broken by design, as they would resolve differently depending on whether
 221          * they are used before or after the relevant configuration setting. Hence: don't add them.
 222          */
 223
 224         assert(u);
 225         assert(format);
 226         assert(ret);
 227
 228         const Specifier table[] = {
 229                 { 'i', specifier_string,                   u->instance },
 230                 { 'I', specifier_instance_unescaped,       NULL },
 231                 { 'j', specifier_last_component,           NULL },
 232                 { 'J', specifier_last_component_unescaped, NULL },
 233                 { 'n', specifier_string,                   u->id },
 234                 { 'N', specifier_prefix_and_instance,      NULL },
 235                 { 'p', specifier_prefix,                   NULL },
 236                 { 'P', specifier_prefix_unescaped,         NULL },
 237
 238                 { 'f', specifier_filename,                 NULL },
 239                 { 'y', specifier_real_path,                u->fragment_path },
 240                 { 'Y', specifier_real_directory,           u->fragment_path },
 241
 242                 { 'c', specifier_cgroup,                   NULL },  /* deprecated, see 1b89b0c499cd4bf0ff389caab4ecaae6e75f9d4e */
 243                 { 'r', specifier_cgroup_slice,             NULL },  /* deprecated, see 1b89b0c499cd4bf0ff389caab4ecaae6e75f9d4e */
 244                 { 'R', specifier_cgroup_root,              NULL },  /* deprecated, see 1b89b0c499cd4bf0ff389caab4ecaae6e75f9d4e */
 245
 246                 { 'C', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CACHE) },
 247                 { 'd', specifier_credentials_dir,          NULL },
 248                 { 'E', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CONFIGURATION) },
 249                 { 'L', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_LOGS) },
 250                 { 'S', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_STATE) },
 251                 { 't', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_RUNTIME) },
 252
 253                 { 'h', specifier_user_home,                NULL },
 254                 { 's', specifier_user_shell,               NULL },
 255
 256                 COMMON_SYSTEM_SPECIFIERS,
 257
 258                 COMMON_CREDS_SPECIFIERS(u->manager->runtime_scope),
 259
 260                 COMMON_TMP_SPECIFIERS,
 261                 {}
 262         };
 263
 264         return specifier_printf(format, max_length, table, NULL, u, ret);
 265 }