target/linux/ath79/files/drivers/mtd/tplinkpart.c

   1 /*
   2  * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published
   6  * by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/magic.h>
  15
  16 #include <linux/mtd/mtd.h>
  17 #include <linux/mtd/partitions.h>
  18 #include <linux/version.h>
  19
  20 #define TPLINK_NUM_PARTS        5
  21 #define TPLINK_HEADER_V1        0x01000000
  22 #define TPLINK_HEADER_V2        0x02000000
  23 #define MD5SUM_LEN              16
  24
  25 #define TPLINK_ART_LEN          0x10000
  26 #define TPLINK_KERNEL_OFFS      0x20000
  27 #define TPLINK_64K_KERNEL_OFFS  0x10000
  28
  29 struct tplink_fw_header {
  30         uint32_t        version;        /* header version */
  31         char            vendor_name[24];
  32         char            fw_version[36];
  33         uint32_t        hw_id;          /* hardware id */
  34         uint32_t        hw_rev;         /* hardware revision */
  35         uint32_t        unk1;
  36         uint8_t         md5sum1[MD5SUM_LEN];
  37         uint32_t        unk2;
  38         uint8_t         md5sum2[MD5SUM_LEN];
  39         uint32_t        unk3;
  40         uint32_t        kernel_la;      /* kernel load address */
  41         uint32_t        kernel_ep;      /* kernel entry point */
  42         uint32_t        fw_length;      /* total length of the firmware */
  43         uint32_t        kernel_ofs;     /* kernel data offset */
  44         uint32_t        kernel_len;     /* kernel data length */
  45         uint32_t        rootfs_ofs;     /* rootfs data offset */
  46         uint32_t        rootfs_len;     /* rootfs data length */
  47         uint32_t        boot_ofs;       /* bootloader data offset */
  48         uint32_t        boot_len;       /* bootloader data length */
  49         uint8_t         pad[360];
  50 } __attribute__ ((packed));
  51
  52 static struct tplink_fw_header *
  53 tplink_read_header(struct mtd_info *mtd, size_t offset)
  54 {
  55         struct tplink_fw_header *header;
  56         size_t header_len;
  57         size_t retlen;
  58         int ret;
  59         u32 t;
  60
  61         header = vmalloc(sizeof(*header));
  62         if (!header)
  63                 goto err;
  64
  65         header_len = sizeof(struct tplink_fw_header);
  66         ret = mtd_read(mtd, offset, header_len, &retlen,
  67                        (unsigned char *) header);
  68         if (ret)
  69                 goto err_free_header;
  70
  71         if (retlen != header_len)
  72                 goto err_free_header;
  73
  74         /* sanity checks */
  75         t = be32_to_cpu(header->version);
  76         if ((t != TPLINK_HEADER_V1) && (t != TPLINK_HEADER_V2))
  77                 goto err_free_header;
  78
  79         t = be32_to_cpu(header->kernel_ofs);
  80         if (t != header_len)
  81                 goto err_free_header;
  82
  83         return header;
  84
  85 err_free_header:
  86         vfree(header);
  87 err:
  88         return NULL;
  89 }
  90
  91 static int tplink_check_rootfs_magic(struct mtd_info *mtd, size_t offset)
  92 {
  93         u32 magic;
  94         size_t retlen;
  95         int ret;
  96
  97         ret = mtd_read(mtd, offset, sizeof(magic), &retlen,
  98                        (unsigned char *) &magic);
  99         if (ret)
 100                 return ret;
 101
 102         if (retlen != sizeof(magic))
 103                 return -EIO;
 104
 105         if (le32_to_cpu(magic) != SQUASHFS_MAGIC &&
 106             magic != 0x19852003)
 107                 return -EINVAL;
 108
 109         return 0;
 110 }
 111
 112 static int tplink_parse_partitions_offset(struct mtd_info *master,
 113 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 114                                    struct mtd_partition **pparts,
 115 #else
 116                                    const struct mtd_partition **pparts,
 117 #endif
 118                                    struct mtd_part_parser_data *data,
 119                                    size_t offset)
 120 {
 121         struct mtd_partition *parts;
 122         struct tplink_fw_header *header;
 123         int nr_parts;
 124         size_t art_offset;
 125         size_t rootfs_offset;
 126         size_t squashfs_offset;
 127         int ret;
 128
 129         nr_parts = TPLINK_NUM_PARTS;
 130         parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
 131         if (!parts) {
 132                 ret = -ENOMEM;
 133                 goto err;
 134         }
 135
 136         header = tplink_read_header(master, offset);
 137         if (!header) {
 138                 pr_notice("%s: no TP-Link header found\n", master->name);
 139                 ret = -ENODEV;
 140                 goto err_free_parts;
 141         }
 142
 143         squashfs_offset = offset + sizeof(struct tplink_fw_header) +
 144                           be32_to_cpu(header->kernel_len);
 145
 146         ret = tplink_check_rootfs_magic(master, squashfs_offset);
 147         if (ret == 0)
 148                 rootfs_offset = squashfs_offset;
 149         else
 150                 rootfs_offset = offset + be32_to_cpu(header->rootfs_ofs);
 151
 152         art_offset = master->size - TPLINK_ART_LEN;
 153
 154         parts[0].name = "u-boot";
 155         parts[0].offset = 0;
 156         parts[0].size = offset;
 157         parts[0].mask_flags = MTD_WRITEABLE;
 158
 159         parts[1].name = "kernel";
 160         parts[1].offset = offset;
 161         parts[1].size = rootfs_offset - offset;
 162
 163         parts[2].name = "rootfs";
 164         parts[2].offset = rootfs_offset;
 165         parts[2].size = art_offset - rootfs_offset;
 166
 167         parts[3].name = "art";
 168         parts[3].offset = art_offset;
 169         parts[3].size = TPLINK_ART_LEN;
 170         parts[3].mask_flags = MTD_WRITEABLE;
 171
 172         parts[4].name = "firmware";
 173         parts[4].offset = offset;
 174         parts[4].size = art_offset - offset;
 175
 176         vfree(header);
 177
 178         *pparts = parts;
 179         return nr_parts;
 180
 181 err_free_parts:
 182         kfree(parts);
 183 err:
 184         *pparts = NULL;
 185         return ret;
 186 }
 187
 188 static int tplink_parse_partitions(struct mtd_info *master,
 189 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 190                                    struct mtd_partition **pparts,
 191 #else
 192                                    const struct mtd_partition **pparts,
 193 #endif
 194                                    struct mtd_part_parser_data *data)
 195 {
 196         return tplink_parse_partitions_offset(master, pparts, data,
 197                                               TPLINK_KERNEL_OFFS);
 198 }
 199
 200 static int tplink_parse_64k_partitions(struct mtd_info *master,
 201 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 202                                    struct mtd_partition **pparts,
 203 #else
 204                                    const struct mtd_partition **pparts,
 205 #endif
 206                                    struct mtd_part_parser_data *data)
 207 {
 208         return tplink_parse_partitions_offset(master, pparts, data,
 209                                               TPLINK_64K_KERNEL_OFFS);
 210 }
 211
 212 static struct mtd_part_parser tplink_parser = {
 213         .owner          = THIS_MODULE,
 214         .parse_fn       = tplink_parse_partitions,
 215         .name           = "tp-link",
 216 };
 217
 218 static struct mtd_part_parser tplink_64k_parser = {
 219         .owner          = THIS_MODULE,
 220         .parse_fn       = tplink_parse_64k_partitions,
 221         .name           = "tp-link-64k",
 222 };
 223
 224 static int __init tplink_parser_init(void)
 225 {
 226         register_mtd_parser(&tplink_parser);
 227         register_mtd_parser(&tplink_64k_parser);
 228
 229         return 0;
 230 }
 231
 232 module_init(tplink_parser_init);
 233
 234 MODULE_LICENSE("GPL v2");
 235 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");