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 const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
  12         [DEVICE_DEAD] = UNIT_INACTIVE,
  13         [DEVICE_AVAILABLE] = UNIT_ACTIVE
  14 };
  15
  16 static const char* const state_string_table[_DEVICE_STATE_MAX] = {
  17         [DEVICE_DEAD] = "dead",
  18         [DEVICE_AVAILABLE] = "available"
  19 };
  20
  21 static void device_done(Unit *u) {
  22         Device *d = DEVICE(u);
  23
  24         assert(d);
  25         free(d->sysfs);
  26 }
  27
  28 static void device_set_state(Device *d, DeviceState state) {
  29         DeviceState old_state;
  30         assert(d);
  31
  32         old_state = d->state;
  33         d->state = state;
  34
  35         log_debug("%s changed %s → %s", unit_id(UNIT(d)), state_string_table[old_state], state_string_table[state]);
  36
  37         unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state]);
  38 }
  39
  40 static int device_coldplug(Unit *u) {
  41         Device *d = DEVICE(u);
  42
  43         assert(d);
  44         assert(d->state == DEVICE_DEAD);
  45
  46         if (d->sysfs)
  47                 device_set_state(d, DEVICE_AVAILABLE);
  48
  49         return 0;
  50 }
  51
  52 static void device_dump(Unit *u, FILE *f, const char *prefix) {
  53         Device *d = DEVICE(u);
  54
  55         assert(d);
  56
  57         fprintf(f,
  58                 "%sDevice State: %s\n"
  59                 "%sSysfs Path: %s\n",
  60                 prefix, state_string_table[d->state],
  61                 prefix, strna(d->sysfs));
  62 }
  63
  64 static UnitActiveState device_active_state(Unit *u) {
  65         assert(u);
  66
  67         return state_translation_table[DEVICE(u)->state];
  68 }
  69
  70 static int device_add_escaped_name(Unit *u, const char *prefix, const char *dn, bool make_id) {
  71         char *e;
  72         int r;
  73
  74         assert(u);
  75         assert(dn);
  76         assert(dn[0] == '/');
  77
  78         if (!(e = unit_name_escape_path(prefix, dn+1, ".device")))
  79                 return -ENOMEM;
  80
  81         r = unit_add_name(u, e);
  82
  83         if (r >= 0 && make_id)
  84                 unit_choose_id(u, e);
  85
  86         free(e);
  87
  88         if (r < 0 && r != -EEXIST)
  89                 return r;
  90
  91         return 0;
  92 }
  93
  94 static int device_process_device(Manager *m, struct udev_device *dev) {
  95         const char *dn, *names, *wants, *sysfs;
  96         Unit *u = NULL;
  97         int r;
  98         char *e, *w, *state;
  99         size_t l;
 100         bool delete;
 101         struct udev_list_entry *item = NULL, *first = NULL;
 102
 103         assert(m);
 104
 105         /* Check whether this entry is even relevant for us. */
 106         dn = udev_device_get_devnode(dev);
 107         names = udev_device_get_property_value(dev, "SYSTEMD_NAMES");
 108         wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS");
 109
 110         if (!dn && !names && !wants)
 111                 return 0;
 112
 113         /* Ok, seems kinda interesting. Now, let's see if this one
 114          * already exists. */
 115
 116         if (!(sysfs = udev_device_get_syspath(dev)))
 117                 return -ENOMEM;
 118
 119         assert(sysfs[0] == '/');
 120         if (!(e = unit_name_escape_path("sysfs-", sysfs+1, ".device")))
 121                 return -ENOMEM;
 122
 123         if (!(u = manager_get_unit(m, e))) {
 124                 const char *model;
 125
 126                 delete = true;
 127
 128                 if (!(u = unit_new(m))) {
 129                         free(e);
 130                         return -ENOMEM;
 131                 }
 132
 133                 r = unit_add_name(u, e);
 134                 free(e);
 135
 136                 if (r < 0)
 137                         goto fail;
 138
 139                 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
 140                         r = -ENOMEM;
 141                         goto fail;
 142                 }
 143
 144                 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
 145                     (model = udev_device_get_property_value(dev, "ID_MODEL")))
 146                         if ((r = unit_set_description(u, model)) < 0)
 147                                 goto fail;
 148
 149         } else {
 150                 delete = false;
 151                 free(e);
 152         }
 153
 154         if (dn)
 155                 if ((r = device_add_escaped_name(u, "node-", dn, true)) < 0)
 156                         goto fail;
 157
 158         first = udev_device_get_devlinks_list_entry(dev);
 159         udev_list_entry_foreach(item, first)
 160                 if ((r = device_add_escaped_name(u, "node-", udev_list_entry_get_name(item), false)) < 0)
 161                         goto fail;
 162
 163         if (names) {
 164                 FOREACH_WORD(w, l, names, state) {
 165                         if (!(e = strndup(w, l)))
 166                                 goto fail;
 167
 168                         r = unit_add_name(u, e);
 169                         free(e);
 170
 171                         if (r < 0 && r != -EEXIST)
 172                                 goto fail;
 173                 }
 174         }
 175
 176
 177         if (set_isempty(u->meta.names)) {
 178                 r = -EEXIST;
 179                 goto fail;
 180         }
 181
 182         if (wants) {
 183                 FOREACH_WORD(w, l, wants, state) {
 184                         if (!(e = strndup(w, l)))
 185                                 goto fail;
 186
 187                         r = unit_add_dependency_by_name(u, UNIT_WANTS, e);
 188                         free(e);
 189
 190                         if (r < 0)
 191                                 goto fail;
 192                 }
 193         }
 194
 195         unit_add_to_load_queue(u);
 196         return 0;
 197
 198 fail:
 199         if (delete && u)
 200                 unit_free(u);
 201         return r;
 202 }
 203
 204 static int device_process_path(Manager *m, const char *path) {
 205         int r;
 206         struct udev_device *dev;
 207
 208         assert(m);
 209         assert(path);
 210
 211         if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
 212                 log_warning("Failed to get udev device object from udev for path %s.", path);
 213                 return -ENOMEM;
 214         }
 215
 216         r = device_process_device(m, dev);
 217         udev_device_unref(dev);
 218         return r;
 219 }
 220
 221 static void device_shutdown(Manager *m) {
 222         assert(m);
 223
 224         if (m->udev)
 225                 udev_unref(m->udev);
 226 }
 227
 228 static int device_enumerate(Manager *m) {
 229         int r;
 230         struct udev_enumerate *e = NULL;
 231         struct udev_list_entry *item = NULL, *first = NULL;
 232
 233         assert(m);
 234
 235         if (!(m->udev = udev_new()))
 236                 return -ENOMEM;
 237
 238         if (!(e = udev_enumerate_new(m->udev))) {
 239                 r = -ENOMEM;
 240                 goto fail;
 241         }
 242
 243         if (udev_enumerate_scan_devices(e) < 0) {
 244                 r = -EIO;
 245                 goto fail;
 246         }
 247
 248         first = udev_enumerate_get_list_entry(e);
 249         udev_list_entry_foreach(item, first)
 250                 device_process_path(m, udev_list_entry_get_name(item));
 251
 252         udev_enumerate_unref(e);
 253
 254         return 0;
 255
 256 fail:
 257         if (e)
 258                 udev_enumerate_unref(e);
 259
 260         device_shutdown(m);
 261         return r;
 262 }
 263
 264 const UnitVTable device_vtable = {
 265         .suffix = ".device",
 266
 267         .init = unit_load_fragment_and_dropin,
 268         .done = device_done,
 269         .coldplug = device_coldplug,
 270
 271         .dump = device_dump,
 272
 273         .active_state = device_active_state,
 274
 275         .enumerate = device_enumerate,
 276         .shutdown = device_shutdown
 277 };