device.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <errno.h>
   4 #include <libudev.h>
   5
   6 #include "unit.h"
   7 #include "device.h"
   8 #include "strv.h"
   9 #include "log.h"
  10
  11 static void device_done(Unit *u) {
  12         Device *d = DEVICE(u);
  13
  14         assert(d);
  15         free(d->sysfs);
  16 }
  17
  18 static void device_dump(Unit *u, FILE *f, const char *prefix) {
  19
  20         static const char* const state_table[_DEVICE_STATE_MAX] = {
  21                 [DEVICE_DEAD] = "dead",
  22                 [DEVICE_AVAILABLE] = "available"
  23         };
  24
  25         Device *d = DEVICE(u);
  26
  27         assert(d);
  28
  29         fprintf(f,
  30                 "%sDevice State: %s\n"
  31                 "%sSysfs Path: %s\n",
  32                 prefix, state_table[d->state],
  33                 prefix, d->sysfs);
  34 }
  35
  36 static int device_add_escaped_name(Unit *u, const char *prefix, const char *dn, bool make_id) {
  37         char *e;
  38         int r;
  39
  40         assert(u);
  41         assert(dn);
  42         assert(dn[0] == '/');
  43
  44         if (!(e = unit_name_escape_path(prefix, dn+1, ".device")))
  45                 return -ENOMEM;
  46
  47         r = unit_add_name(u, e);
  48
  49         if (r >= 0 && make_id)
  50                 unit_choose_id(u, e);
  51
  52         free(e);
  53
  54         if (r < 0 && r != -EEXIST)
  55                 return r;
  56
  57         return 0;
  58 }
  59
  60 static int device_process_device(Manager *m, struct udev_device *dev) {
  61         const char *dn, *names, *wants, *sysfs;
  62         Unit *u = NULL;
  63         int r;
  64         char *e, *w, *state;
  65         size_t l;
  66         bool delete;
  67         struct udev_list_entry *item = NULL, *first = NULL;
  68
  69         assert(m);
  70
  71         /* Check whether this entry is even relevant for us. */
  72         dn = udev_device_get_devnode(dev);
  73         names = udev_device_get_property_value(dev, "SYSTEMD_NAMES");
  74         wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS");
  75
  76         if (!dn && !names && !wants)
  77                 return 0;
  78
  79         /* Ok, seems kinda interesting. Now, let's see if this one
  80          * already exists. */
  81
  82         if (!(sysfs = udev_device_get_syspath(dev)))
  83                 return -ENOMEM;
  84
  85         assert(sysfs[0] == '/');
  86         if (!(e = unit_name_escape_path("sysfs-", sysfs+1, ".device")))
  87                 return -ENOMEM;
  88
  89         if (!(u = manager_get_unit(m, e))) {
  90                 const char *model;
  91
  92                 delete = true;
  93
  94                 if (!(u = unit_new(m))) {
  95                         free(e);
  96                         return -ENOMEM;
  97                 }
  98
  99                 r = unit_add_name(u, e);
 100                 free(e);
 101
 102                 if (r < 0)
 103                         goto fail;
 104
 105                 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
 106                         r = -ENOMEM;
 107                         goto fail;
 108                 }
 109
 110                 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
 111                      (model = udev_device_get_property_value(dev, "ID_MODEL")))
 112                         if (!(u->meta.description = strdup(model))) {
 113                                 r = -ENOMEM;
 114                                 goto fail;
 115                         }
 116
 117         } else {
 118                 delete = false;
 119                 free(e);
 120         }
 121
 122         if (dn)
 123                 if ((r = device_add_escaped_name(u, "node-", dn, true)) < 0)
 124                         goto fail;
 125
 126         first = udev_device_get_devlinks_list_entry(dev);
 127         udev_list_entry_foreach(item, first)
 128                 if ((r = device_add_escaped_name(u, "node-", udev_list_entry_get_name(item), false)) < 0)
 129                         goto fail;
 130
 131         if (names) {
 132                 FOREACH_WORD(w, l, names, state) {
 133                         if (!(e = strndup(w, l)))
 134                                 goto fail;
 135
 136                         r = unit_add_name(u, e);
 137                         free(e);
 138
 139                         if (r < 0 && r != -EEXIST)
 140                                 goto fail;
 141                 }
 142         }
 143
 144
 145         if (set_isempty(u->meta.names)) {
 146                 r = -EEXIST;
 147                 goto fail;
 148         }
 149
 150         if (wants) {
 151                 FOREACH_WORD(w, l, wants, state) {
 152                         if (!(e = strndup(w, l)))
 153                                 goto fail;
 154
 155                         r = unit_add_dependency_by_name(u, UNIT_WANTS, e);
 156                         free(e);
 157
 158                         if (r < 0)
 159                                 goto fail;
 160                 }
 161         }
 162
 163         unit_add_to_load_queue(u);
 164         return 0;
 165
 166 fail:
 167         if (delete && u)
 168                 unit_free(u);
 169         return r;
 170 }
 171
 172 static int device_process_path(Manager *m, const char *path) {
 173         int r;
 174         struct udev_device *dev;
 175
 176         assert(m);
 177         assert(path);
 178
 179         if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
 180                 log_warning("Failed to get udev device object from udev for path %s.", path);
 181                 return -ENOMEM;
 182         }
 183
 184         r = device_process_device(m, dev);
 185         udev_device_unref(dev);
 186         return r;
 187 }
 188
 189 static void device_shutdown(Manager *m) {
 190         assert(m);
 191
 192         if (m->udev)
 193                 udev_unref(m->udev);
 194 }
 195
 196 static int device_enumerate(Manager *m) {
 197         int r;
 198         struct udev_enumerate *e = NULL;
 199         struct udev_list_entry *item = NULL, *first = NULL;
 200
 201         assert(m);
 202
 203         if (!(m->udev = udev_new()))
 204                 return -ENOMEM;
 205
 206         if (!(e = udev_enumerate_new(m->udev))) {
 207                 r = -ENOMEM;
 208                 goto fail;
 209         }
 210
 211         if (udev_enumerate_scan_devices(e) < 0) {
 212                 r = -EIO;
 213                 goto fail;
 214         }
 215
 216         first = udev_enumerate_get_list_entry(e);
 217         udev_list_entry_foreach(item, first)
 218                 device_process_path(m, udev_list_entry_get_name(item));
 219
 220         udev_enumerate_unref(e);
 221
 222         return 0;
 223
 224 fail:
 225         if (e)
 226                 udev_enumerate_unref(e);
 227
 228         device_shutdown(m);
 229         return r;
 230 }
 231
 232 static UnitActiveState device_active_state(Unit *u) {
 233         return DEVICE(u)->state == DEVICE_DEAD ? UNIT_INACTIVE : UNIT_ACTIVE;
 234 }
 235
 236 const UnitVTable device_vtable = {
 237         .suffix = ".device",
 238
 239         .init = unit_load_fragment_and_dropin,
 240         .done = device_done,
 241         .dump = device_dump,
 242
 243         .enumerate = device_enumerate,
 244         .shutdown = device_shutdown,
 245
 246         .active_state = device_active_state
 247 };