libfdisk/src/utils.c

   1
   2 #include "fdiskP.h"
   3 #include "pathnames.h"
   4
   5 #include <ctype.h>
   6
   7
   8 /*
   9  * Zeros in-memory first sector buffer
  10  */
  11 void fdisk_zeroize_firstsector(struct fdisk_context *cxt)
  12 {
  13         if (!cxt || !cxt->firstsector)
  14                 return;
  15
  16         DBG(CONTEXT, ul_debug("zeroize in-memory first sector buffer"));
  17         memset(cxt->firstsector, 0, cxt->sector_size);
  18 }
  19
  20 int fdisk_read_firstsector(struct fdisk_context *cxt)
  21 {
  22         ssize_t r;
  23
  24         assert(cxt);
  25         assert(cxt->sector_size);
  26
  27         DBG(TOPOLOGY, ul_debug("initialize first sector "
  28                                 "buffer [sector_size=%lu]", cxt->sector_size));
  29
  30         if (!cxt->firstsector) {
  31                 cxt->firstsector = calloc(1, cxt->sector_size);
  32                 if (!cxt->firstsector)
  33                         return -ENOMEM;
  34         } else
  35                 fdisk_zeroize_firstsector(cxt);
  36
  37         r = read(cxt->dev_fd, cxt->firstsector, cxt->sector_size);
  38
  39         if (r != cxt->sector_size) {
  40                 if (!errno)
  41                         errno = EINVAL; /* probably too small file/device */
  42                 DBG(TOPOLOGY, ul_debug("failed to read first sector %m"));
  43                 return -errno;
  44         }
  45
  46         return 0;
  47 }
  48
  49 /*
  50  * Return allocated buffer with partition name
  51  */
  52 char *fdisk_partname(const char *dev, size_t partno)
  53 {
  54         char *res = NULL;
  55         const char *p = "";
  56         int w = 0;
  57
  58         if (!dev || !*dev) {
  59                 if (asprintf(&res, "%zd", partno) > 0)
  60                         return res;
  61                 return NULL;
  62         }
  63
  64         w = strlen(dev);
  65         if (isdigit(dev[w - 1]))
  66                 p = "p";
  67
  68         /* devfs kludge - note: fdisk partition names are not supposed
  69            to equal kernel names, so there is no reason to do this */
  70         if (strcmp(dev + w - 4, "disc") == 0) {
  71                 w -= 4;
  72                 p = "part";
  73         }
  74
  75         /* udev names partitions by appending -partN
  76            e.g. ata-SAMSUNG_SV8004H_0357J1FT712448-part1 */
  77         if ((strncmp(dev, _PATH_DEV_BYID, sizeof(_PATH_DEV_BYID) - 1) == 0) ||
  78              strncmp(dev, _PATH_DEV_BYPATH, sizeof(_PATH_DEV_BYPATH) - 1) == 0) {
  79                p = "-part";
  80         }
  81
  82         if (asprintf(&res, "%.*s%s%zu", w, dev, p, partno) > 0)
  83                 return res;
  84
  85         return NULL;
  86 }
  87
  88 #ifdef TEST_PROGRAM
  89 struct fdisk_label *fdisk_new_dos_label(struct fdisk_context *cxt) { return NULL; }
  90 struct fdisk_label *fdisk_new_bsd_label(struct fdisk_context *cxt) { return NULL; }
  91
  92 int test_partnames(struct fdisk_test *ts, int argc, char *argv[])
  93 {
  94         size_t i;
  95         const char *disk = argv[1];
  96
  97         for (i = 0; i < 5; i++) {
  98                 char *p = fdisk_partname(disk, i + 1);
  99                 if (p)
 100                         printf("%zu: '%s'\n", i + 1, p);
 101                 free(p);
 102         }
 103
 104         return 0;
 105 }
 106
 107 int main(int argc, char *argv[])
 108 {
 109         struct fdisk_test tss[] = {
 110                 { "--partnames",  test_partnames,  "<diskname>" },
 111                 { NULL }
 112         };
 113
 114         return fdisk_run_test(tss, argc, argv);
 115 }
 116
 117 #endif