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 {
  43         int rc;
  44         int sz = 0;
  45         int pos0 = 0, pos1 = 0;
  46         char *spaces;
  47
  48         sz = strlen(current);
  49         spaces = alloca(sz+1);
  50         memset(spaces, ' ', sz+1);
  51         spaces[sz] = '\0';
  52         sz = 0;
  53
  54         debug("entry");
  55         /*
  56          * This structure is completely ridiculous.
  57          *
  58          * /dev/sdc as SAS looks like:
  59          * /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
  60          * /dev/sdc1 looks like:
  61          * /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
  62          *
  63          * OR
  64          *
  65          * /dev/sdc as SAS looks like:
  66          * /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
  67          * /dev/sdc1 looks like:
  68          * /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
  69          *
  70          * /sys/block/sdc/device looks like:
  71          * device-> ../../../4:2:0:0
  72          *
  73          */
  74
  75         /*
  76          * So we start when current is:
  77          * host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc/sdc1
  78          */
  79         uint32_t tosser0, tosser1, tosser2;
  80
  81         /* ignore a bunch of stuff
  82          *    host4/port-4:0
  83          * or host4/port-4:0:0
  84          */
  85         debug("searching for host4/");
  86         rc = sscanf(current, "host%d/%n", scsi_host, &pos0);
  87         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
  88         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 1);
  89         if (rc != 1)
  90                 return -1;
  91         sz += pos0;
  92         pos0 = 0;
  93
  94         debug("searching for port-4:0 or port-4:0:0");
  95         rc = sscanf(current, "port-%d:%d%n:%d%n", &tosser0,
  96                     &tosser1, &pos0, &tosser2, &pos1);
  97         debug("current:\"%s\" rc:%d pos0:%d pos1:%d\n", current+sz, rc, pos0, pos1);
  98         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);
  99         arrow(LOG_DEBUG, spaces, 9, pos1, rc, 3);
 100         if (rc == 2 || rc == 3) {
 101                 sz += pos0;
 102                 pos0 = 0;
 103
 104                 /* next:
 105                  *    /end_device-4:0
 106                  * or /end_device-4:0:0
 107                  * awesomely these are the exact same fields that go into port-blah,
 108                  * but we don't care for now about any of them anyway.
 109                  */
 110                 debug("searching for /end_device-4:0/ or /end_device-4:0:0/");
 111                 rc = sscanf(current + sz, "/end_device-%d:%d%n", &tosser0, &tosser1, &pos0);
 112                 debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 113                 arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);
 114                 if (rc != 2)
 115                         return -1;
 116                 sz += pos0;
 117                 pos0 = 0;
 118
 119                 rc = sscanf(current + sz, ":%d%n", &tosser0, &pos0);
 120                 debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 121                 arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);
 122                 if (rc != 0 && rc != 1)
 123                         return -1;
 124                 sz += pos0;
 125                 pos0 = 0;
 126
 127                 if (current[sz] == '/')
 128                         sz += 1;
 129         } else if (rc != 0) {
 130                 return -1;
 131         }
 132
 133         /* now:
 134          * /target4:0:0/
 135          */
 136         uint64_t tosser3;
 137         debug("searching for target4:0:0/");
 138         rc = sscanf(current + sz, "target%d:%d:%"PRIu64"/%n", &tosser0, &tosser1,
 139                     &tosser3, &pos0);
 140         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 141         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 3);
 142         if (rc != 3)
 143                 return -1;
 144         sz += pos0;
 145         pos0 = 0;
 146
 147         /* now:
 148          * %d:%d:%d:%llu/
 149          */
 150         debug("searching for 4:0:0:0/");
 151         rc = sscanf(current + sz, "%d:%d:%d:%"PRIu64"/%n",
 152                     scsi_bus, scsi_device, scsi_target, scsi_lun, &pos0);
 153         debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
 154         arrow(LOG_DEBUG, spaces, 9, pos0, rc, 4);
 155         if (rc != 4)
 156                 return -1;
 157         sz += pos0;
 158
 159         return sz;
 160 }
 161
 162 static ssize_t
 163 parse_scsi(struct device *dev, const char *current, const char *root UNUSED)
 164 {
 165         uint32_t scsi_host, scsi_bus, scsi_device, scsi_target;
 166         uint64_t scsi_lun;
 167         ssize_t sz;
 168         int pos;
 169         int rc;
 170         char *spaces;
 171
 172         pos = strlen(current);
 173         spaces = alloca(pos+1);
 174         memset(spaces, ' ', pos+1);
 175         spaces[pos] = '\0';
 176         pos = 0;
 177
 178         debug("entry");
 179
 180         debug("searching for ../../../0:0:0:0");
 181         rc = sscanf(dev->device, "../../../%d:%d:%d:%"PRIu64"%n",
 182                     &dev->scsi_info.scsi_bus,
 183                     &dev->scsi_info.scsi_device,
 184                     &dev->scsi_info.scsi_target,
 185                     &dev->scsi_info.scsi_lun,
 186                     &pos);
 187         debug("current:\"%s\" rc:%d pos:%d\n", dev->device, rc, pos);
 188         arrow(LOG_DEBUG, spaces, 9, pos, rc, 3);
 189         if (rc != 4)
 190                 return 0;
 191
 192         sz = parse_scsi_link(current, &scsi_host,
 193                               &scsi_bus, &scsi_device,
 194                               &scsi_target, &scsi_lun);
 195         if (sz < 0)
 196                 return 0;
 197
 198         /*
 199          * SCSI disks can have up to 16 partitions, or 4 bits worth
 200          * and have one bit for the disk number.
 201          */
 202         if (dev->major == 8) {
 203                 dev->interface_type = scsi;
 204                 dev->disknum = (dev->minor >> 4);
 205                 set_part(dev, dev->minor & 0xF);
 206         } else if (dev->major >= 65 && dev->major <= 71) {
 207                 dev->interface_type = scsi;
 208                 dev->disknum = 16*(dev->major-64) + (dev->minor >> 4);
 209                 set_part(dev, dev->minor & 0xF);
 210         } else if (dev->major >= 128 && dev->major <= 135) {
 211                 dev->interface_type = scsi;
 212                 dev->disknum = 16*(dev->major-128) + (dev->minor >> 4);
 213                 set_part(dev, dev->minor & 0xF);
 214         } else {
 215                 efi_error("couldn't parse scsi major/minor");
 216                 return -1;
 217         }
 218
 219         return sz;
 220 }
 221
 222 static ssize_t
 223 dp_create_scsi(struct device *dev,
 224                uint8_t *buf,  ssize_t size, ssize_t off)
 225 {
 226         ssize_t sz = 0;
 227
 228         debug("entry");
 229
 230         sz = efidp_make_scsi(buf + off, size ? size - off : 0,
 231                              dev->scsi_info.scsi_target,
 232                              dev->scsi_info.scsi_lun);
 233         if (sz < 0)
 234                 efi_error("efidp_make_scsi() failed");
 235
 236         return sz;
 237 }
 238
 239 enum interface_type scsi_iftypes[] = { scsi, unknown };
 240
 241 struct dev_probe HIDDEN scsi_parser = {
 242         .name = "scsi",
 243         .iftypes = scsi_iftypes,
 244         .flags = DEV_PROVIDES_HD,
 245         .parse = parse_scsi,
 246         .create = dp_create_scsi,
 247 };