src/shared/install-printf.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Zbigniew Jędrzejewski-Szmek
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 #include "formats-util.h"
  26 #include "install-printf.h"
  27 #include "install.h"
  28 #include "macro.h"
  29 #include "specifier.h"
  30 #include "unit-name.h"
  31 #include "user-util.h"
  32
  33 static int specifier_prefix_and_instance(char specifier, void *data, void *userdata, char **ret) {
  34         UnitFileInstallInfo *i = userdata;
  35
  36         assert(i);
  37
  38         return unit_name_to_prefix_and_instance(i->name, ret);
  39 }
  40
  41 static int specifier_prefix(char specifier, void *data, void *userdata, char **ret) {
  42         UnitFileInstallInfo *i = userdata;
  43
  44         assert(i);
  45
  46         return unit_name_to_prefix(i->name, ret);
  47 }
  48
  49 static int specifier_instance(char specifier, void *data, void *userdata, char **ret) {
  50         UnitFileInstallInfo *i = userdata;
  51         char *instance;
  52         int r;
  53
  54         assert(i);
  55
  56         r = unit_name_to_instance(i->name, &instance);
  57         if (r < 0)
  58                 return r;
  59
  60         if (!instance) {
  61                 instance = strdup("");
  62                 if (!instance)
  63                         return -ENOMEM;
  64         }
  65
  66         *ret = instance;
  67         return 0;
  68 }
  69
  70 static int specifier_user_name(char specifier, void *data, void *userdata, char **ret) {
  71         char *t;
  72
  73         /* If we are UID 0 (root), this will not result in NSS,
  74          * otherwise it might. This is good, as we want to be able to
  75          * run this in PID 1, where our user ID is 0, but where NSS
  76          * lookups are not allowed. */
  77
  78         t = getusername_malloc();
  79         if (!t)
  80                 return -ENOMEM;
  81
  82         *ret = t;
  83         return 0;
  84 }
  85
  86 static int specifier_user_id(char specifier, void *data, void *userdata, char **ret) {
  87
  88         if (asprintf(ret, UID_FMT, getuid()) < 0)
  89                 return -ENOMEM;
  90
  91         return 0;
  92 }
  93
  94 int install_full_printf(UnitFileInstallInfo *i, const char *format, char **ret) {
  95
  96         /* This is similar to unit_full_printf() but does not support
  97          * anything path-related.
  98          *
  99          * %n: the full id of the unit                 (foo@bar.waldo)
 100          * %N: the id of the unit without the suffix   (foo@bar)
 101          * %p: the prefix                              (foo)
 102          * %i: the instance                            (bar)
 103
 104          * %U the UID of the running user
 105          * %u the username of running user
 106          * %m the machine ID of the running system
 107          * %H the host name of the running system
 108          * %b the boot ID of the running system
 109          * %v `uname -r` of the running system
 110          */
 111
 112         const Specifier table[] = {
 113                 { 'n', specifier_string,              i->name },
 114                 { 'N', specifier_prefix_and_instance, NULL },
 115                 { 'p', specifier_prefix,              NULL },
 116                 { 'i', specifier_instance,            NULL },
 117
 118                 { 'U', specifier_user_id,             NULL },
 119                 { 'u', specifier_user_name,           NULL },
 120
 121                 { 'm', specifier_machine_id,          NULL },
 122                 { 'H', specifier_host_name,           NULL },
 123                 { 'b', specifier_boot_id,             NULL },
 124                 { 'v', specifier_kernel_release,      NULL },
 125                 {}
 126         };
 127
 128         assert(i);
 129         assert(format);
 130         assert(ret);
 131
 132         return specifier_printf(format, table, i, ret);
 133 }