libfdisk: basic fdisk_dump_* functions

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 343 insertions, 0 deletions

diff --git a/libfdisk/src/dump.c b/libfdisk/src/dump.c
new file mode 100644
index 000000000..2c9e7530e
--- /dev/null
+++ b/libfdisk/src/dump.c
@@ -0,0 +1,343 @@
+
+#include "fdiskP.h"
+
+/* dump header (e.g. unit: sectors) */
+struct fdisk_dumpheader {
+	struct list_head	headers;
+	char			*name;
+	char			*data;
+};
+
+/* dump control struct */
+struct fdisk_dump {
+	struct fdisk_table	*table;
+	struct list_head	headers;
+
+	int			refcount;
+
+	/* parser's state */
+	FILE			*file;
+	size_t			line;
+};
+
+
+static void fdisk_dump_free_header(struct fdisk_dump *dp, struct fdisk_dumpheader *fi)
+{
+	if (!fi)
+		return;
+
+	DBG(DUMP, ul_debugobj(fi, "free"));
+	free(fi->name);
+	free(fi->data);
+	list_del(&fi->headers);
+	free(fi);
+}
+
+/**
+ * fdisk_new_dump:
+ *
+ * The dump hold fdisk_table and additional information to read/write
+ * dump to the file.
+ *
+ * Returns: newly allocated dump struct.
+ */
+struct fdisk_dump *fdisk_new_dump(void)
+{
+	struct fdisk_dump *dp = NULL;
+
+	dp = calloc(1, sizeof(*dp));
+	if (!dp)
+		return NULL;
+
+	DBG(DUMP, ul_debugobj(dp, "alloc"));
+	dp->refcount = 1;
+	INIT_LIST_HEAD(&dp->headers);
+	return dp;
+}
+
+/**
+ * fdisk_ref_dump:
+ * @dp: dump pointer
+ *
+ * Incremparts reference counter.
+ */
+void fdisk_ref_dump(struct fdisk_dump *dp)
+{
+	if (dp)
+		dp->refcount++;
+}
+
+static void fdisk_reset_dump(struct fdisk_dump *dp)
+{
+	assert(dp);
+
+	fdisk_unref_table(dp->table);
+	dp->table = NULL;
+
+	while (!list_empty(&dp->headers)) {
+		struct fdisk_dumpheader *fi = list_entry(dp->headers.next,
+						  struct fdisk_dumpheader, headers);
+		fdisk_dump_free_header(dp, fi);
+	}
+	INIT_LIST_HEAD(&dp->headers);
+}
+
+/**
+ * fdisk_unref_dump:
+ * @dp: dump pointer
+ *
+ * De-incremparts reference counter, on zero the @dp is automatically
+ * deallocated.
+ */
+void fdisk_unref_dump(struct fdisk_dump *dp)
+{
+	if (!dp)
+		return;
+
+	dp->refcount--;
+	if (dp->refcount <= 0) {
+		fdisk_reset_dump(dp);
+		DBG(DUMP, ul_debugobj(dp, "free"));
+		free(dp);
+	}
+}
+
+static struct fdisk_dumpheader *fdisk_dump_get_header(struct fdisk_dump *dp,
+						     const char *name)
+{
+	struct list_head *p;
+
+	list_for_each(p, &dp->headers) {
+		struct fdisk_dumpheader *fi = list_entry(p, struct fdisk_dumpheader, headers);
+
+		if (strcasecmp(fi->name, name) == 0)
+			return fi;
+	}
+
+	return NULL;
+}
+
+/**
+ * fdisk_dump_set_header:
+ * @dp: dump instance
+ * @name: header name
+ * @data: header data (or NULL)
+ *
+ * The headers are used as global options (in dump) for whole partition table, always one
+ * header per line.
+ *
+ * If no @data specified then the header is removed. If header does not exist
+ * and @data speified then a new header added.
+ *
+ * Note that libfdisk allows to specify arbitrary custom header, the default
+ * build-in headers are "unit" and "label", and some label specific headers
+ * (for example "uuid" and "name" for GPT).
+ *
+ * Returns: 0 on success, <0 on error
+ */
+int fdisk_dump_set_header(struct fdisk_dump *dp,
+			    const char *name,
+			    const char *data)
+{
+	struct fdisk_dumpheader *fi;
+
+	assert(dp);
+	assert(name);
+
+	if (!dp || !name)
+		return -EINVAL;
+
+	fi = fdisk_dump_get_header(dp, name);
+	if (!fi && !data)
+		return 0;	/* want to remove header that does not exist, success */
+
+	if (!data) {
+		/* no data, remove the header */
+		fdisk_dump_free_header(dp, fi);
+		return 0;
+	}
+
+	if (!fi) {
+		/* new header */
+		fi = calloc(1, sizeof(*fi));
+		if (!fi)
+			return -ENOMEM;
+		INIT_LIST_HEAD(&fi->headers);
+		fi->name = strdup(name);
+		fi->data = strdup(data);
+		if (!fi->data || !fi->name) {
+			fdisk_dump_free_header(dp, fi);
+			return -ENOMEM;
+		}
+		list_add_tail(&fi->headers, &dp->headers);
+	} else {
+		/* update existing */
+		char *x = strdup(data);
+
+		if (!x)
+			return -ENOMEM;
+		free(fi->data);
+		fi->data = x;
+	}
+
+	return 0;
+}
+
+/**
+ * fdisk_dump_get_table:
+ * @dp: dump
+ *
+ * The table (container with partitions) is possible to create by
+ * fdisk_dump_read_context() or fdisk_dump_read_file(), otherwise
+ * this function returns NULL.
+ *
+ * Returns: NULL or dump.
+ */
+struct fdisk_table *fdisk_dump_get_table(struct fdisk_dump *dp)
+{
+	assert(dp);
+	return dp ? dp->table : NULL;
+}
+
+/**
+ * fdisk_dump_read_context:
+ * @dp: dump
+ * @cxt: context
+ *
+ * Reads data from the current context (on disk partition table).
+ *
+ * Return: 0 on success, <0 on error.
+ */
+int fdisk_dump_read_context(struct fdisk_dump *dp, struct fdisk_context *cxt)
+{
+	struct fdisk_label *lb;
+	int rc;
+	char *p = NULL;
+
+	assert(dp);
+	assert(cxt);
+
+	if (!dp || !cxt)
+		return -EINVAL;
+
+	fdisk_reset_dump(dp);
+
+	lb = fdisk_get_label(cxt, NULL);
+	if (!lb)
+		return -EINVAL;
+
+	/* allocate and fill new table */
+	rc = fdisk_get_partitions(cxt, &dp->table);
+	if (rc)
+		return rc;
+
+	/* generate headers */
+	rc = fdisk_dump_set_header(dp, "label", fdisk_label_get_name(lb));
+
+	if (!rc && fdisk_get_disklabel_id(cxt, &p) == 0 && p) {
+		rc = fdisk_dump_set_header(dp, "label-id", p);
+		free(p);
+	}
+	if (!rc && cxt->dev_path)
+		rc = fdisk_dump_set_header(dp, "device", cxt->dev_path);
+	if (!rc)
+		rc = fdisk_dump_set_header(dp, "unit", "sectors");
+
+	/* TODO: label specific headers (e.g. uuid for GPT) */
+
+	return rc;
+}
+
+int fdisk_dump_write_file(struct fdisk_dump *dp, FILE *f)
+{
+	struct list_head *h;
+	struct fdisk_partition *pa;
+	struct fdisk_iter itr;
+	const char *devname = NULL;
+
+	assert(dp);
+	assert(f);
+
+	/* dump headers */
+	list_for_each(h, &dp->headers) {
+		struct fdisk_dumpheader *fi = list_entry(h, struct fdisk_dumpheader, headers);
+		fprintf(f, "%s: %s\n", fi->name, fi->data);
+		if (strcmp(fi->name, "device") == 0)
+			devname = fi->data;
+	}
+
+	if (!dp->table)
+		return 0;
+
+	fputc('\n', f);
+
+	fdisk_reset_iter(&itr, FDISK_ITER_FORWARD);
+	while (fdisk_table_next_partition(dp->table, &itr, &pa) == 0) {
+		char *p = NULL;
+
+		if (devname)
+			p = fdisk_partname(devname, pa->partno + 1);
+		if (p)
+			fprintf(f, "%s: ", p);
+		else
+			fprintf(f, "%zu :", pa->partno + 1);
+
+		if (pa->start)
+			fprintf(f, " start=%12ju", pa->start);
+		if (pa->size)
+			fprintf(f, ", size=%12ju", pa->size);
+		else if (pa->end)
+			fprintf(f, ", end=%12ju", pa->end);
+
+		if (pa->type && fdisk_parttype_get_string(pa->type))
+			fprintf(f, ", type=%s", fdisk_parttype_get_string(pa->type));
+		else if (pa->type)
+			fprintf(f, ", type=%x", fdisk_parttype_get_code(pa->type));
+
+		if (pa->uuid)
+			fprintf(f, ", uuid=%s", pa->uuid);
+		if (pa->name && *pa->name)
+			fprintf(f, ", name=\"%s\"", pa->name);
+		if (pa->attrs)
+			fprintf(f, ", attrs=%s", pa->attrs);
+		if (pa->boot)
+			fprintf(f, ", bootable");
+		fputc('\n', f);
+	}
+
+	return 0;
+}
+
+#ifdef TEST_PROGRAM
+int test_dump(struct fdisk_test *ts, int argc, char *argv[])
+{
+	char *devname = argv[1];
+	struct fdisk_context *cxt;
+	struct fdisk_dump *dp;
+
+	cxt = fdisk_new_context();
+	fdisk_assign_device(cxt, devname, 1);
+
+	dp = fdisk_new_dump();
+	fdisk_dump_read_context(dp, cxt);
+	fdisk_dump_set_header(dp, "custom-header-foo", "bar");
+
+	fdisk_free_context(cxt);
+
+	fdisk_dump_write_file(dp, stdout);
+	fdisk_unref_dump(dp);
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct fdisk_test tss[] = {
+	{ "--dump",  test_dump,    "<device>   print PT" },
+	{ NULL }
+	};
+
+	return fdisk_run_test(tss, argc, argv);
+}
+
+#endif