1 files changed, 154 insertions, 0 deletions
diff --git a/libblkid/libfdisk/src/utils.c b/libblkid/libfdisk/src/utils.c
new file mode 100644
index 000000000..482a3062d
--- /dev/null
+++ b/libblkid/libfdisk/src/utils.c
@@ -0,0 +1,154 @@
+
+#include "fdiskP.h"
+#include "pathnames.h"
+
+#include <ctype.h>
+
+/**
+ * SECTION: utils
+ * @title: Utils
+ * @short_description: misc fdisk functions
+ */
+
+/*
+ * Zeros in-memory first sector buffer
+ */
+int fdisk_init_firstsector_buffer(struct fdisk_context *cxt)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	if (!cxt->firstsector || cxt->firstsector_bufsz != cxt->sector_size) {
+		/* Let's allocate a new buffer if no allocated yet, or the
+		 * current buffer has incorrect size */
+		if (!cxt->parent || cxt->parent->firstsector != cxt->firstsector)
+			free(cxt->firstsector);
+
+		DBG(CXT, ul_debugobj(cxt, "initialize in-memory first sector "
+				"buffer [sector_size=%lu]", cxt->sector_size));
+		cxt->firstsector = calloc(1, cxt->sector_size);
+		if (!cxt->firstsector)
+			return -ENOMEM;
+
+		cxt->firstsector_bufsz = cxt->sector_size;
+		return 0;
+	}
+
+	DBG(CXT, ul_debugobj(cxt, "zeroize in-memory first sector buffer"));
+	memset(cxt->firstsector, 0, cxt->firstsector_bufsz);
+	return 0;
+}
+
+int fdisk_read_firstsector(struct fdisk_context *cxt)
+{
+	ssize_t r;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->sector_size);
+
+	rc = fdisk_init_firstsector_buffer(cxt);
+	if (rc)
+		return rc;
+
+	assert(cxt->sector_size == cxt->firstsector_bufsz);
+
+	DBG(CXT, ul_debugobj(cxt, "reading first sector "
+				"buffer [sector_size=%lu]", cxt->sector_size));
+
+	r = lseek(cxt->dev_fd, 0, SEEK_SET);
+	if (r == -1)
+	{
+		DBG(CXT, ul_debugobj(cxt, "failed to seek to first sector %m"));
+		return -errno;
+	}
+
+	r = read(cxt->dev_fd, cxt->firstsector, cxt->sector_size);
+
+	if (r != cxt->sector_size) {
+		if (!errno)
+			errno = EINVAL;	/* probably too small file/device */
+		DBG(CXT, ul_debugobj(cxt, "failed to read first sector %m"));
+		return -errno;
+	}
+
+	return 0;
+}
+
+/**
+ * fdisk_partname:
+ * @dev: device name
+ * @partno: partition name
+ *
+ * Return: allocated buffer with partition name, use free() to deallocate.
+ */
+char *fdisk_partname(const char *dev, size_t partno)
+{
+	char *res = NULL;
+	const char *p = "";
+	int w = 0;
+
+	if (!dev || !*dev) {
+		if (asprintf(&res, "%zd", partno) > 0)
+			return res;
+		return NULL;
+	}
+
+	w = strlen(dev);
+	if (isdigit(dev[w - 1]))
+#ifdef __GNU__
+		p = "s";
+#else
+		p = "p";
+#endif
+
+	/* devfs kludge - note: fdisk partition names are not supposed
+	   to equal kernel names, so there is no reason to do this */
+	if (strcmp(dev + w - 4, "disc") == 0) {
+		w -= 4;
+		p = "part";
+	}
+
+	/* udev names partitions by appending -partN
+	   e.g. ata-SAMSUNG_SV8004H_0357J1FT712448-part1 */
+	if ((strncmp(dev, _PATH_DEV_BYID, sizeof(_PATH_DEV_BYID) - 1) == 0) ||
+	     strncmp(dev, _PATH_DEV_BYPATH, sizeof(_PATH_DEV_BYPATH) - 1) == 0) {
+	       p = "-part";
+	}
+
+	if (asprintf(&res, "%.*s%s%zu", w, dev, p, partno) > 0)
+		return res;
+
+	return NULL;
+}
+
+#ifdef TEST_PROGRAM
+struct fdisk_label *fdisk_new_dos_label(struct fdisk_context *cxt) { return NULL; }
+struct fdisk_label *fdisk_new_bsd_label(struct fdisk_context *cxt) { return NULL; }
+
+int test_partnames(struct fdisk_test *ts, int argc, char *argv[])
+{
+	size_t i;
+	const char *disk = argv[1];
+
+	for (i = 0; i < 5; i++) {
+		char *p = fdisk_partname(disk, i + 1);
+		if (p)
+			printf("%zu: '%s'\n", i + 1, p);
+		free(p);
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct fdisk_test tss[] = {
+		{ "--partnames",  test_partnames,  "<diskname>" },
+		{ NULL }
+	};
+
+	return fdisk_run_test(tss, argc, argv);
+}
+
+#endif