src/linux-scsi.c

   1 /*
   2  * libefiboot - library for the manipulation of EFI boot variables
   3  * Copyright 2012-2018 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public License as
   7  * published by the Free Software Foundation; either version 2.1 of the
   8  * License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, see
  17  * <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "fix_coverity.h"
  22
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <inttypes.h>
  26 #include <stdint.h>
  27 #include <unistd.h>
  28
  29 #include "efiboot.h"
  30
  31 /*
  32  * support for Old-school SCSI devices
  33  */
  34
  35 /*
  36  * helper for scsi formats...
  37  */
  38 ssize_t HIDDEN
  39 parse_scsi_link(const char *current, uint32_t *scsi_host,
  40                 uint32_t *scsi_bus, uint32_t *scsi_device,
  41                 uint32_t *scsi_target, uint64_t *scsi_lun,
  42                 uint32_t *local_port_id, uint32_t *remote_port_id,
  43                 uint32_t *remote_target_id)
  44 {
  45         int rc;
  46         int sz = 0;
  47         int pos0 = 0, pos1 = 0;
  48         char *spaces;
  49
  50         sz = strlen(current);
  51         spaces = alloca(sz+1);
  52         memset(spaces, ' ', sz+1);
  53         spaces[sz] = '\0';
  54         sz = 0;
  55
  56         debug("entry");
  57         /*
  58          * This structure is completely ridiculous.
  59          *
  60          * /dev/sdc as SAS looks like:
  61          * /sys/dev/block/8:32 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc
  62          * /dev/sdc1 looks like:
  63          * /sys/dev/block/8:33 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc/sdc1
  64          *
  65          * OR
  66          *
  67          * /dev/sdc as SAS looks like:
  68          * /sys/dev/block/8:32 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:2:0/end_device-4:2:0/target4:2:0/4:2:0:0/block/sdc
  69          * /dev/sdc1 looks like:
  70          * /sys/dev/block/8:33 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:2:0/end_device-4:2:0/target4:2:0/4:2:0:0/block/sdc/sdc1
  71          *
  72          * /sys/block/sdc/device looks like:
  73          * device-> ../../../4:2:0:0
  74          *
  75          * OR
  76          *
  77          * 8:0 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda
  78          * 8:1 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
  79          *
  80          * /sys/block/sda/device looks like:
  81          * device -> ../../../2:0:0:0 *
  82          *
  83          * sas_address exists, but it's hard to find:
  84          * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address
  85          * but sas_host_address is nowhere to be found, and sas_address
  86          * doesn't directly exist under /sys/class/ anywhere.  So you actually
  87          * have to go to
  88          * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address
  89          * and chop that off to
  90          * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/
  91          * and then add a bunch of port and end device crap to it to get:
  92          * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/sas_device/end_device-2:0:2/sas_address
  93
  94          */
  95
  96         /*
  97          * So we start when current is:
  98          * host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc/sdc1
  99          * or
 100          * host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
 101          */
 102         uint32_t tosser0, tosser1, tosser2;
 103
 104         /* ignore a bunch of stuff
 105          *    host4/port-4:0
 106          * or host4/port-4:0:0
 107          */
 108         debug("searching for host4/");
 109         rc = sscanf(current, "host%d/%n", scsi_host, &pos0);
 110         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 111         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 1);
 112         if (rc != 1)
 113                 return -1;
 114         sz += pos0;
 115         pos0 = 0;
 116
 117         /*
 118          * We might have this next:
 119          * port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
 120          * or:
 121          * port-2:0/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
 122          * or maybe (not sure):
 123          * port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
 124          */
 125         debug("searching for port-4:0 or port-4:0:0");
 126         rc = sscanf(current+sz, "port-%d:%d%n:%d%n", &tosser0,
 127                     &tosser1, &pos0, &tosser2, &pos1);
 128         debug("current:\"%s\" rc:%d pos0:%d pos1:%d\n", current+sz, rc, pos0, pos1);
 129         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);
 130         arrow(LOG_DEBUG, spaces, 9, pos1, rc, 3);
 131         if (rc == 2 || rc == 3) {
 132                 sz += pos0;
 133                 pos0 = 0;
 134                 if (local_port_id && rc == 2)
 135                         *local_port_id = tosser1;
 136                 if (remote_port_id && rc == 3)
 137                         *remote_port_id = tosser2;
 138
 139                 if (current[sz] == '/')
 140                         sz += 1;
 141
 142                 /*
 143                  * We might have this next:
 144                  * expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
 145                  *                       ^ port id
 146                  *                     ^ scsi target id
 147                  *                   ^ host number
 148                  *          ^ host number
 149                  * We don't actually care about either number in expander-.../,
 150                  * because they're replicated in all the other places.  We just need
 151                  * to get past it.
 152                  */
 153                 debug("searching for expander-4:0/");
 154                 rc = sscanf(current+sz, "expander-%d:%d/%n", &tosser0, &tosser1, &pos0);
 155                 debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 156                 arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);
 157                 if (rc == 2) {
 158                         if (!remote_target_id) {
 159                                 efi_error("Device is PHY is a remote target, but remote_target_id is NULL");
 160                                 return -1;
 161                         }
 162                         *remote_target_id = tosser1;
 163                         sz += pos0;
 164                         pos0 = 0;
 165
 166                         /*
 167                          * if we have that, we should have a 3-part port next
 168                          */
 169                         debug("searching for port-2:0:2/");
 170                         rc = sscanf(current+sz, "port-%d:%d:%d/%n", &tosser0, &tosser1, &tosser2, &pos0);
 171                         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 172                         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 3);
 173                         if (rc != 3) {
 174                                 efi_error("Couldn't parse port expander port string");
 175                                 return -1;
 176                         }
 177                         sz += pos0;
 178                 }
 179                 pos0 = 0;
 180
 181                 /* next:
 182                  *    /end_device-4:0
 183                  * or /end_device-4:0:0
 184                  * awesomely these are the exact same fields that go into port-blah,
 185                  * but we don't care for now about any of them anyway.
 186                  */
 187                 debug("searching for end_device-4:0/ or end_device-4:0:0/");
 188                 rc = sscanf(current + sz, "end_device-%d:%d%n", &tosser0, &tosser1, &pos0);
 189                 debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 190                 if (rc != 2)
 191                         return -1;
 192
 193                 pos1 = 0;
 194                 rc = sscanf(current + sz + pos0, ":%d%n", &tosser2, &pos1);
 195                 arrow(LOG_DEBUG, spaces, 9, pos0, rc + 2, 2);
 196                 arrow(LOG_DEBUG, spaces, 9, pos0 + pos1, rc + 2, 3);
 197                 if (rc != 0 && rc != 1)
 198                         return -1;
 199                 if (remote_port_id && rc == 1)
 200                         *remote_port_id = tosser2;
 201                 if (local_port_id && rc == 0)
 202                         *local_port_id = tosser1;
 203                 sz += pos0 + pos1;
 204                 pos0 = pos1 = 0;
 205
 206                 if (current[sz] == '/')
 207                         sz += 1;
 208         } else if (rc != 0) {
 209                 return -1;
 210         }
 211
 212         /* now:
 213          * /target4:0:0/
 214          */
 215         uint64_t tosser3;
 216         debug("searching for target4:0:0/");
 217         rc = sscanf(current + sz, "target%d:%d:%"PRIu64"/%n", &tosser0, &tosser1,
 218                     &tosser3, &pos0);
 219         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 220         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 3);
 221         if (rc != 3)
 222                 return -1;
 223         sz += pos0;
 224         pos0 = 0;
 225
 226         /* now:
 227          * %d:%d:%d:%llu/
 228          */
 229         debug("searching for 4:0:0:0/");
 230         rc = sscanf(current + sz, "%d:%d:%d:%"PRIu64"/%n",
 231                     scsi_bus, scsi_device, scsi_target, scsi_lun, &pos0);
 232         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 233         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 4);
 234         if (rc != 4)
 235                 return -1;
 236         sz += pos0;
 237
 238         debug("returning %d", sz);
 239         return sz;
 240 }
 241
 242 static ssize_t
 243 parse_scsi(struct device *dev, const char *current, const char *root UNUSED)
 244 {
 245         uint32_t scsi_host, scsi_bus, scsi_device, scsi_target;
 246         uint64_t scsi_lun;
 247         ssize_t sz;
 248         int pos;
 249         int rc;
 250         char *spaces;
 251
 252         pos = strlen(current);
 253         spaces = alloca(pos+1);
 254         memset(spaces, ' ', pos+1);
 255         spaces[pos] = '\0';
 256         pos = 0;
 257
 258         debug("entry");
 259
 260         debug("searching for ../../../0:0:0:0");
 261         rc = sscanf(dev->device, "../../../%d:%d:%d:%"PRIu64"%n",
 262                     &dev->scsi_info.scsi_bus,
 263                     &dev->scsi_info.scsi_device,
 264                     &dev->scsi_info.scsi_target,
 265                     &dev->scsi_info.scsi_lun,
 266                     &pos);
 267         debug("current:\"%s\" rc:%d pos:%d\n", dev->device, rc, pos);
 268         arrow(LOG_DEBUG, spaces, 9, pos, rc, 3);
 269         if (rc != 4)
 270                 return 0;
 271
 272         sz = parse_scsi_link(current, &scsi_host,
 273                               &scsi_bus, &scsi_device,
 274                               &scsi_target, &scsi_lun,
 275                               NULL, NULL, NULL);
 276         if (sz < 0)
 277                 return 0;
 278
 279         /*
 280          * SCSI disks can have up to 16 partitions, or 4 bits worth
 281          * and have one bit for the disk number.
 282          */
 283         if (dev->major == 8) {
 284                 dev->interface_type = scsi;
 285                 dev->disknum = (dev->minor >> 4);
 286                 set_part(dev, dev->minor & 0xF);
 287         } else if (dev->major >= 65 && dev->major <= 71) {
 288                 dev->interface_type = scsi;
 289                 dev->disknum = 16*(dev->major-64) + (dev->minor >> 4);
 290                 set_part(dev, dev->minor & 0xF);
 291         } else if (dev->major >= 128 && dev->major <= 135) {
 292                 dev->interface_type = scsi;
 293                 dev->disknum = 16*(dev->major-128) + (dev->minor >> 4);
 294                 set_part(dev, dev->minor & 0xF);
 295         } else {
 296                 efi_error("couldn't parse scsi major/minor");
 297                 return -1;
 298         }
 299
 300         return sz;
 301 }
 302
 303 static ssize_t
 304 dp_create_scsi(struct device *dev,
 305                uint8_t *buf,  ssize_t size, ssize_t off)
 306 {
 307         ssize_t sz = 0;
 308
 309         debug("entry");
 310
 311         sz = efidp_make_scsi(buf + off, size ? size - off : 0,
 312                              dev->scsi_info.scsi_target,
 313                              dev->scsi_info.scsi_lun);
 314         if (sz < 0)
 315                 efi_error("efidp_make_scsi() failed");
 316
 317         return sz;
 318 }
 319
 320 enum interface_type scsi_iftypes[] = { scsi, unknown };
 321
 322 struct dev_probe HIDDEN scsi_parser = {
 323         .name = "scsi",
 324         .iftypes = scsi_iftypes,
 325         .flags = DEV_PROVIDES_HD,
 326         .parse = parse_scsi,
 327         .create = dp_create_scsi,
 328 };