src/core/unit-printf.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include "sd-path.h"
   4
   5 #include "alloc-util.h"
   6 #include "creds-util.h"
   7 #include "env-util.h"
   8 #include "fd-util.h"
   9 #include "fileio.h"
  10 #include "manager.h"
  11 #include "specifier.h"
  12 #include "string-util.h"
  13 #include "unit.h"
  14 #include "unit-name.h"
  15 #include "unit-printf.h"
  16
  17 static int specifier_prefix_and_instance(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  18         const Unit *u = ASSERT_PTR(userdata);
  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 char *root, const void *userdata, char **ret) {
  24         const Unit *u = ASSERT_PTR(userdata);
  25
  26         return unit_name_to_prefix(u->id, ret);
  27 }
  28
  29 static int specifier_prefix_unescaped(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  30         _cleanup_free_ char *p = NULL;
  31         const Unit *u = ASSERT_PTR(userdata);
  32         int r;
  33
  34         r = unit_name_to_prefix(u->id, &p);
  35         if (r < 0)
  36                 return r;
  37
  38         return unit_name_unescape(p, ret);
  39 }
  40
  41 static int specifier_instance_unescaped(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  42         const Unit *u = ASSERT_PTR(userdata);
  43
  44         return unit_name_unescape(strempty(u->instance), ret);
  45 }
  46
  47 static int specifier_last_component(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  48         const Unit *u = ASSERT_PTR(userdata);
  49         _cleanup_free_ char *prefix = NULL;
  50         char *dash;
  51         int r;
  52
  53         r = unit_name_to_prefix(u->id, &prefix);
  54         if (r < 0)
  55                 return r;
  56
  57         dash = strrchr(prefix, '-');
  58         if (dash)
  59                 return specifier_string(specifier, dash + 1, root, userdata, ret);
  60
  61         *ret = TAKE_PTR(prefix);
  62         return 0;
  63 }
  64
  65 static int specifier_last_component_unescaped(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  66         _cleanup_free_ char *p = NULL;
  67         int r;
  68
  69         r = specifier_last_component(specifier, data, root, userdata, &p);
  70         if (r < 0)
  71                 return r;
  72
  73         return unit_name_unescape(p, ret);
  74 }
  75
  76 static int specifier_filename(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  77         const Unit *u = ASSERT_PTR(userdata);
  78
  79         if (u->instance)
  80                 return unit_name_path_unescape(u->instance, ret);
  81         else
  82                 return unit_name_to_path(u->id, ret);
  83 }
  84
  85 static void bad_specifier(const Unit *u, char specifier) {
  86         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);
  87 }
  88
  89 static int specifier_cgroup(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  90         const Unit *u = ASSERT_PTR(userdata);
  91
  92         bad_specifier(u, specifier);
  93
  94         return unit_get_cgroup_path_with_fallback(u, ret);
  95 }
  96
  97 static int specifier_cgroup_root(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
  98         const Unit *u = ASSERT_PTR(userdata);
  99
 100         bad_specifier(u, specifier);
 101
 102         return strdup_to(ret, u->manager->cgroup_root);
 103 }
 104
 105 static int specifier_cgroup_slice(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 106         const Unit *u = ASSERT_PTR(userdata), *slice;
 107
 108         bad_specifier(u, specifier);
 109
 110         slice = UNIT_GET_SLICE(u);
 111         if (slice)
 112                 return unit_get_cgroup_path_with_fallback(slice, ret);
 113
 114         return strdup_to(ret, u->manager->cgroup_root);
 115 }
 116
 117 static int specifier_special_directory(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 118         const Unit *u = ASSERT_PTR(userdata);
 119
 120         return strdup_to(ret, u->manager->prefix[PTR_TO_UINT(data)]);
 121 }
 122
 123 static int specifier_credentials_dir(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 124         const Unit *u = ASSERT_PTR(userdata);
 125         char *d;
 126
 127         assert(ret);
 128
 129         d = strjoin(u->manager->prefix[EXEC_DIRECTORY_RUNTIME], "/credentials/", u->id);
 130         if (!d)
 131                 return -ENOMEM;
 132
 133         *ret = d;
 134         return 0;
 135 }
 136
 137 static int specifier_shared_data_dir(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
 138         const Unit *u = ASSERT_PTR(userdata);
 139
 140         assert(ret);
 141
 142         return sd_path_lookup(MANAGER_IS_SYSTEM(u->manager) ? SD_PATH_SYSTEM_SHARED : SD_PATH_USER_SHARED, NULL, ret);
 143 }
 144
 145 int unit_name_printf(const Unit *u, const char* format, char **ret) {
 146         /*
 147          * This will use the passed string as format string and replace the following specifiers (which should all be
 148          * safe for inclusion in unit names):
 149          *
 150          * %n: the full id of the unit                 (foo-aaa@bar.waldo)
 151          * %N: the id of the unit without the suffix   (foo-aaa@bar)
 152          * %p: the prefix                              (foo-aaa)
 153          * %i: the instance                            (bar)
 154          * %j: the last component of the prefix        (aaa)
 155          */
 156
 157         const Specifier table[] = {
 158                 { 'i', specifier_string,              u->instance },
 159                 { 'j', specifier_last_component,      NULL },
 160                 { 'n', specifier_string,              u->id },
 161                 { 'N', specifier_prefix_and_instance, NULL },
 162                 { 'p', specifier_prefix,              NULL },
 163
 164                 COMMON_SYSTEM_SPECIFIERS,
 165
 166                 COMMON_CREDS_SPECIFIERS(u->manager->runtime_scope),
 167                 {}
 168         };
 169
 170         assert(u);
 171         assert(format);
 172         assert(ret);
 173
 174         return specifier_printf(format, UNIT_NAME_MAX, table, NULL, u, ret);
 175 }
 176
 177 int unit_full_printf_full(const Unit *u, const char *format, size_t max_length, char **ret) {
 178         /* This is similar to unit_name_printf() but also supports unescaping. Also, adds a couple of
 179          * additional codes (which are likely not suitable for unescaped inclusion in unit names):
 180          *
 181          * %f: the unescaped instance if set, otherwise the id unescaped as path
 182          *
 183          * %c: cgroup path of unit (deprecated)
 184          * %r: where units in this slice are placed in the cgroup tree (deprecated)
 185          * %R: the root of this systemd's instance tree (deprecated)
 186          *
 187          * %C: the cache directory root (e.g. /var/cache or $XDG_CACHE_HOME)
 188          * %d: the credentials directory ($CREDENTIALS_DIRECTORY)
 189          * %D: the shared data root (e.g. /usr/share or $XDG_DATA_HOME)
 190          * %E: the configuration directory root (e.g. /etc or $XDG_CONFIG_HOME)
 191          * %L: the log directory root (e.g. /var/log or $XDG_STATE_HOME/log)
 192          * %S: the state directory root (e.g. /var/lib or $XDG_STATE_HOME)
 193          * %t: the runtime directory root (e.g. /run or $XDG_RUNTIME_DIR)
 194          *
 195          * %h: the homedir of the running user
 196          * %s: the shell of the running user
 197          *
 198          * NOTICE: When you add new entries here, please be careful: specifiers which depend on settings of
 199          * the unit file itself are broken by design, as they would resolve differently depending on whether
 200          * they are used before or after the relevant configuration setting. Hence: don't add them.
 201          */
 202
 203         assert(u);
 204         assert(format);
 205         assert(ret);
 206
 207         const Specifier table[] = {
 208                 { 'i', specifier_string,                   u->instance },
 209                 { 'I', specifier_instance_unescaped,       NULL },
 210                 { 'j', specifier_last_component,           NULL },
 211                 { 'J', specifier_last_component_unescaped, NULL },
 212                 { 'n', specifier_string,                   u->id },
 213                 { 'N', specifier_prefix_and_instance,      NULL },
 214                 { 'p', specifier_prefix,                   NULL },
 215                 { 'P', specifier_prefix_unescaped,         NULL },
 216
 217                 { 'f', specifier_filename,                 NULL },
 218                 { 'y', specifier_real_path,                u->fragment_path },
 219                 { 'Y', specifier_real_directory,           u->fragment_path },
 220
 221                 { 'c', specifier_cgroup,                   NULL },  /* deprecated, see 1b89b0c499cd4bf0ff389caab4ecaae6e75f9d4e */
 222                 { 'r', specifier_cgroup_slice,             NULL },  /* deprecated, see 1b89b0c499cd4bf0ff389caab4ecaae6e75f9d4e */
 223                 { 'R', specifier_cgroup_root,              NULL },  /* deprecated, see 1b89b0c499cd4bf0ff389caab4ecaae6e75f9d4e */
 224
 225                 { 'C', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CACHE) },
 226                 { 'd', specifier_credentials_dir,          NULL },
 227                 { 'D', specifier_shared_data_dir,          NULL },
 228                 { 'E', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_CONFIGURATION) },
 229                 { 'L', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_LOGS) },
 230                 { 'S', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_STATE) },
 231                 { 't', specifier_special_directory,        UINT_TO_PTR(EXEC_DIRECTORY_RUNTIME) },
 232
 233                 { 'h', specifier_user_home,                NULL },
 234                 { 's', specifier_user_shell,               NULL },
 235
 236                 COMMON_SYSTEM_SPECIFIERS,
 237
 238                 COMMON_CREDS_SPECIFIERS(u->manager->runtime_scope),
 239
 240                 COMMON_TMP_SPECIFIERS,
 241                 {}
 242         };
 243
 244         return specifier_printf(format, max_length, table, NULL, u, ret);
 245 }
 246
 247 int unit_full_printf(const Unit *u, const char *text, char **ret) {
 248         return unit_full_printf_full(u, text, LONG_LINE_MAX, ret);
 249 }
 250
 251 int unit_path_printf(const Unit *u, const char *text, char **ret) {
 252         return unit_full_printf_full(u, text, PATH_MAX-1, ret);
 253 }
 254
 255 int unit_fd_printf(const Unit *u, const char *text, char **ret) {
 256         return unit_full_printf_full(u, text, FDNAME_MAX, ret);
 257 }
 258
 259 int unit_cred_printf(const Unit *u, const char *text, char **ret) {
 260         return unit_full_printf_full(u, text, CREDENTIAL_NAME_MAX, ret);
 261 }
 262
 263 int unit_env_printf(const Unit *u, const char *text, char **ret) {
 264         return unit_full_printf_full(u, text, sc_arg_max(), ret);
 265 }