src/shared/install-printf.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Zbigniew Jędrzejewski-Szmek
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <stdlib.h>
  23
  24 #include "alloc-util.h"
  25 #include "formats-util.h"
  26 #include "install-printf.h"
  27 #include "specifier.h"
  28 #include "unit-name.h"
  29 #include "user-util.h"
  30 #include "util.h"
  31
  32 static int specifier_prefix_and_instance(char specifier, void *data, void *userdata, char **ret) {
  33         UnitFileInstallInfo *i = userdata;
  34
  35         assert(i);
  36
  37         return unit_name_to_prefix_and_instance(i->name, ret);
  38 }
  39
  40 static int specifier_prefix(char specifier, void *data, void *userdata, char **ret) {
  41         UnitFileInstallInfo *i = userdata;
  42
  43         assert(i);
  44
  45         return unit_name_to_prefix(i->name, ret);
  46 }
  47
  48 static int specifier_instance(char specifier, void *data, void *userdata, char **ret) {
  49         UnitFileInstallInfo *i = userdata;
  50         char *instance;
  51         int r;
  52
  53         assert(i);
  54
  55         r = unit_name_to_instance(i->name, &instance);
  56         if (r < 0)
  57                 return r;
  58
  59         if (!instance) {
  60                 instance = strdup("");
  61                 if (!instance)
  62                         return -ENOMEM;
  63         }
  64
  65         *ret = instance;
  66         return 0;
  67 }
  68
  69 static int specifier_user_name(char specifier, void *data, void *userdata, char **ret) {
  70         char *t;
  71
  72         /* If we are UID 0 (root), this will not result in NSS,
  73          * otherwise it might. This is good, as we want to be able to
  74          * run this in PID 1, where our user ID is 0, but where NSS
  75          * lookups are not allowed. */
  76
  77         t = getusername_malloc();
  78         if (!t)
  79                 return -ENOMEM;
  80
  81         *ret = t;
  82         return 0;
  83 }
  84
  85 static int specifier_user_id(char specifier, void *data, void *userdata, char **ret) {
  86
  87         if (asprintf(ret, UID_FMT, getuid()) < 0)
  88                 return -ENOMEM;
  89
  90         return 0;
  91 }
  92
  93 int install_full_printf(UnitFileInstallInfo *i, const char *format, char **ret) {
  94
  95         /* This is similar to unit_full_printf() but does not support
  96          * anything path-related.
  97          *
  98          * %n: the full id of the unit                 (foo@bar.waldo)
  99          * %N: the id of the unit without the suffix   (foo@bar)
 100          * %p: the prefix                              (foo)
 101          * %i: the instance                            (bar)
 102
 103          * %U the UID of the running user
 104          * %u the username of running user
 105          * %m the machine ID of the running system
 106          * %H the host name of the running system
 107          * %b the boot ID of the running system
 108          * %v `uname -r` of the running system
 109          */
 110
 111         const Specifier table[] = {
 112                 { 'n', specifier_string,              i->name },
 113                 { 'N', specifier_prefix_and_instance, NULL },
 114                 { 'p', specifier_prefix,              NULL },
 115                 { 'i', specifier_instance,            NULL },
 116
 117                 { 'U', specifier_user_id,             NULL },
 118                 { 'u', specifier_user_name,           NULL },
 119
 120                 { 'm', specifier_machine_id,          NULL },
 121                 { 'H', specifier_host_name,           NULL },
 122                 { 'b', specifier_boot_id,             NULL },
 123                 { 'v', specifier_kernel_release,      NULL },
 124                 {}
 125         };
 126
 127         assert(i);
 128         assert(format);
 129         assert(ret);
 130
 131         return specifier_printf(format, table, i, ret);
 132 }