[PATCH V2 2/2] mtd: parsers: add TP-Link SafeLoader partitions table parser
Rafał Miłecki
zajec5 at gmail.com
Tue Oct 11 22:04:42 PDT 2022
From: Rafał Miłecki <rafal at milecki.pl>
This parser deals with most TP-Link home routers. It reads info about
partitions and registers them in the MTD subsystem.
Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
V2: Fix types (thanks kernel test robot)
Fix off-by-one when setting '\0'
---
drivers/mtd/parsers/Kconfig | 15 +++
drivers/mtd/parsers/Makefile | 1 +
drivers/mtd/parsers/tplink_safeloader.c | 150 ++++++++++++++++++++++++
3 files changed, 166 insertions(+)
create mode 100644 drivers/mtd/parsers/tplink_safeloader.c
diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
index aaa06050c9bc..c258ba2a3a6f 100644
--- a/drivers/mtd/parsers/Kconfig
+++ b/drivers/mtd/parsers/Kconfig
@@ -123,6 +123,21 @@ config MTD_AFS_PARTS
for your particular device. It won't happen automatically. The
'physmap' map driver (CONFIG_MTD_PHYSMAP) does this, for example.
+config MTD_PARSER_TPLINK_SAFELOADER
+ tristate "TP-Link Safeloader partitions parser"
+ depends on MTD && (ARCH_BCM_5301X || ATH79 || SOC_MT7620 || SOC_MT7621 || COMPILE_TEST)
+ help
+ TP-Link home routers use flash partitions to store various data. Info
+ about flash space layout is stored in a partitions table using a
+ custom ASCII-based format.
+
+ That format was first found in devices with SafeLoader bootloader and
+ was named after it. Later it was adapted to CFE and U-Boot
+ bootloaders.
+
+ This driver reads partitions table, parses it and creates MTD
+ partitions.
+
config MTD_PARSER_TRX
tristate "Parser for TRX format partitions"
depends on MTD && (BCM47XX || ARCH_BCM_5301X || ARCH_MEDIATEK || RALINK || COMPILE_TEST)
diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index 23fa4de4016f..0e70b621a1d8 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -10,6 +10,7 @@ ofpart-$(CONFIG_MTD_OF_PARTS_BCM4908) += ofpart_bcm4908.o
ofpart-$(CONFIG_MTD_OF_PARTS_LINKSYS_NS)+= ofpart_linksys_ns.o
obj-$(CONFIG_MTD_PARSER_IMAGETAG) += parser_imagetag.o
obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
+obj-$(CONFIG_MTD_PARSER_TPLINK_SAFELOADER) += tplink_safeloader.o
obj-$(CONFIG_MTD_PARSER_TRX) += parser_trx.o
obj-$(CONFIG_MTD_SERCOMM_PARTS) += scpart.o
obj-$(CONFIG_MTD_SHARPSL_PARTS) += sharpslpart.o
diff --git a/drivers/mtd/parsers/tplink_safeloader.c b/drivers/mtd/parsers/tplink_safeloader.c
new file mode 100644
index 000000000000..23584a477391
--- /dev/null
+++ b/drivers/mtd/parsers/tplink_safeloader.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2022 Rafał Miłecki <rafal at milecki.pl>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#define TPLINK_SAFELOADER_DATA_OFFSET 4
+#define TPLINK_SAFELOADER_MAX_PARTS 32
+
+struct safeloader_cmn_header {
+ __be32 size;
+ uint32_t unused;
+} __packed;
+
+static void *mtd_parser_tplink_safeloader_read_table(struct mtd_info *mtd)
+{
+ struct safeloader_cmn_header hdr;
+ struct device_node *np;
+ size_t bytes_read;
+ size_t offset;
+ size_t size;
+ char *buf;
+ int err;
+
+ np = mtd_get_of_node(mtd);
+ if (mtd_is_partition(mtd))
+ of_node_get(np);
+ else
+ np = of_get_child_by_name(np, "partitions");
+
+ if (of_property_read_u32(np, "partitions-table-offset", (u32 *)&offset)) {
+ pr_err("Failed to get partitions table offset\n");
+ goto err_put;
+ }
+
+ err = mtd_read(mtd, offset, sizeof(hdr), &bytes_read, (uint8_t *)&hdr);
+ if (err && !mtd_is_bitflip(err)) {
+ pr_err("Failed to read from %s at 0x%zx\n", mtd->name, offset);
+ goto err_put;
+ }
+
+ size = be32_to_cpu(hdr.size);
+
+ buf = kmalloc(size + 1, GFP_KERNEL);
+ if (!buf)
+ goto err_put;
+
+ err = mtd_read(mtd, offset + sizeof(hdr), size, &bytes_read, buf);
+ if (err && !mtd_is_bitflip(err)) {
+ pr_err("Failed to read from %s at 0x%zx\n", mtd->name, offset + sizeof(hdr));
+ goto err_kfree;
+ }
+
+ buf[size] = '\0';
+
+ of_node_put(np);
+
+ return buf;
+
+err_kfree:
+ kfree(buf);
+err_put:
+ of_node_put(np);
+ return NULL;
+}
+
+static int mtd_parser_tplink_safeloader_parse(struct mtd_info *mtd,
+ const struct mtd_partition **pparts,
+ struct mtd_part_parser_data *data)
+{
+ struct mtd_partition *parts;
+ char name[65];
+ size_t offset;
+ size_t bytes;
+ char *buf;
+ int idx;
+ int err;
+
+ parts = kcalloc(TPLINK_SAFELOADER_MAX_PARTS, sizeof(*parts), GFP_KERNEL);
+ if (!parts) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+
+ buf = mtd_parser_tplink_safeloader_read_table(mtd);
+ if (!buf) {
+ err = -ENOENT;
+ goto err_out;
+ }
+
+ for (idx = 0, offset = TPLINK_SAFELOADER_DATA_OFFSET;
+ idx < TPLINK_SAFELOADER_MAX_PARTS &&
+ sscanf(buf + offset, "partition %64s base 0x%llx size 0x%llx%zn\n",
+ name, &parts[idx].offset, &parts[idx].size, &bytes) == 3;
+ idx++, offset += bytes + 1) {
+ parts[idx].name = kstrdup(name, GFP_KERNEL);
+ if (!parts[idx].name) {
+ err = -ENOMEM;
+ goto err_free;
+ }
+ }
+
+ if (idx == TPLINK_SAFELOADER_MAX_PARTS)
+ pr_warn("Reached maximum number of partitions!\n");
+
+ kfree(buf);
+
+ *pparts = parts;
+
+ return idx;
+
+err_free:
+ for (idx -= 1; idx >= 0; idx--)
+ kfree(parts[idx].name);
+err_out:
+ return err;
+};
+
+static void mtd_parser_tplink_safeloader_cleanup(const struct mtd_partition *pparts,
+ int nr_parts)
+{
+ int i;
+
+ for (i = 0; i < nr_parts; i++)
+ kfree(pparts[i].name);
+
+ kfree(pparts);
+}
+
+static const struct of_device_id mtd_parser_tplink_safeloader_of_match_table[] = {
+ { .compatible = "tplink,safeloader-partitions" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mtd_parser_tplink_safeloader_of_match_table);
+
+static struct mtd_part_parser mtd_parser_tplink_safeloader = {
+ .parse_fn = mtd_parser_tplink_safeloader_parse,
+ .cleanup = mtd_parser_tplink_safeloader_cleanup,
+ .name = "tplink-safeloader",
+ .of_match_table = mtd_parser_tplink_safeloader_of_match_table,
+};
+module_mtd_part_parser(mtd_parser_tplink_safeloader);
+
+MODULE_LICENSE("GPL");
--
2.34.1
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