/*
* Copyright 2010-2011 Christian Lamparter <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include <stdlib.h>
#include <stdio.h>
#include <error.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include "carlfw.h"

struct carlfw_file {
char *name;
size_t len;
char *data;
};

struct carlfw {
struct carlfw_file fw;
struct carlfw_file hdr;

struct list_head desc_list;
unsigned int desc_list_entries,
desc_list_len;
};

#define carlfw_walk_descs(iter, fw) \
list_for_each_entry(iter, &fw->desc_list, h.list)

struct carlfw_list_entry_head {
struct list_head list;
};

struct carlfw_list_entry {
struct carlfw_list_entry_head h;
union {
struct carl9170fw_desc_head head;
uint32_t data[0];
char text[0];
};
};

static inline struct carlfw_list_entry *carlfw_desc_to_entry(struct carl9170fw_desc_head *head)
{
return container_of(head, struct carlfw_list_entry, head);
}

static inline struct carl9170fw_desc_head *carlfw_entry_to_desc(struct carlfw_list_entry *entry)
{
return &entry->head;
}

static void carlfw_entry_unlink(struct carlfw *fw,
struct carlfw_list_entry *entry)
{
fw->desc_list_entries--;
fw->desc_list_len -= le16_to_cpu(entry->head.length);
list_del(&entry->h.list);
}

static void carlfw_entry_del(struct carlfw *fw,
struct carlfw_list_entry *entry)
{
carlfw_entry_unlink(fw, entry);
free(entry);
}

static struct carlfw_list_entry *carlfw_find_entry(struct carlfw *fw,
const uint8_t descid[4],
unsigned int len,
uint8_t compatible_revision)
{
struct carlfw_list_entry *iter;

carlfw_walk_descs(iter, fw) {
if (carl9170fw_desc_cmp(&iter->head, descid, len,
compatible_revision))
return (void *)iter;
}

return NULL;
}

static struct carlfw_list_entry *__carlfw_entry_add_prepare(struct carlfw *fw,
const struct carl9170fw_desc_head *desc)
{
struct carlfw_list_entry *tmp;
unsigned int len;

len = le16_to_cpu(desc->length);

if (len < sizeof(struct carl9170fw_desc_head))
return ERR_PTR(-EINVAL);

tmp = malloc(sizeof(*tmp) + len);
if (!tmp)
return ERR_PTR(-ENOMEM);

fw->desc_list_entries++;
fw->desc_list_len += len;

memcpy(tmp->data, desc, len);
return tmp;
}

static void __carlfw_release(struct carlfw_file *f)
{
f->len = 0;
if (f->name)
free(f->name);
f->name = NULL;

if (f->data)
free(f->data);
f->data = NULL;
}

void carlfw_release(struct carlfw *fw)
{
struct carlfw_list_entry *entry;

if (!IS_ERR_OR_NULL(fw)) {
while (!list_empty(&fw->desc_list)) {
entry = list_entry(fw->desc_list.next,
struct carlfw_list_entry, h.list);
carlfw_entry_del(fw, entry);
}

__carlfw_release(&fw->fw);
__carlfw_release(&fw->hdr);
free(fw);
}
}

static int __carlfw_load(struct carlfw_file *file, const char *name, const char *mode)
{
struct stat file_stat;
FILE *fh;
int err;

fh = fopen(name, mode);
if (fh == NULL)
return errno ? -errno : -1;

err = fstat(fileno(fh), &file_stat);
if (err)
return errno ? -errno : -1;

file->len = file_stat.st_size;
file->data = malloc(file->len);
if (file->data == NULL)
return -ENOMEM;

err = fread(file->data, file->len, 1, fh);
if (err != 1)
return -ferror(fh);

file->name = strdup(name);
fclose(fh);

if (!file->name)
return -ENOMEM;

return 0;
}

static void *__carlfw_find_desc(struct carlfw_file *file,
uint8_t descid[4],
unsigned int len,
uint8_t compatible_revision)
{
int scan = file->len, found = 0;
struct carl9170fw_desc_head *tmp = NULL;

while (scan >= 0) {
if (file->data[scan] == descid[CARL9170FW_MAGIC_SIZE - found - 1])
found++;
else
found = 0;

if (found == CARL9170FW_MAGIC_SIZE)
break;

scan--;
}

if (found == CARL9170FW_MAGIC_SIZE) {
tmp = (void *) &file->data[scan];

if (!CHECK_HDR_VERSION(tmp, compatible_revision) &&
(le16_to_cpu(tmp->length) >= len))
return tmp;
}

return NULL;
}

void *carlfw_find_desc(struct carlfw *fw,
const uint8_t descid[4],
const unsigned int len,
const uint8_t compatible_revision)
{
struct carlfw_list_entry *tmp;

tmp = carlfw_find_entry(fw, descid, len, compatible_revision);

return tmp ? carlfw_entry_to_desc(tmp) : NULL;
}

int carlfw_desc_add_tail(struct carlfw *fw,
const struct carl9170fw_desc_head *desc)
{
struct carlfw_list_entry *tmp;

tmp = __carlfw_entry_add_prepare(fw, desc);
if (IS_ERR(tmp))
return PTR_ERR(tmp);

list_add_tail(&tmp->h.list, &fw->desc_list);
return 0;
}

int carlfw_desc_add(struct carlfw *fw,
const struct carl9170fw_desc_head *desc,
struct carl9170fw_desc_head *prev,
struct carl9170fw_desc_head *next)
{
struct carlfw_list_entry *tmp;

tmp = __carlfw_entry_add_prepare(fw, desc);
if (IS_ERR(tmp))
return PTR_ERR(tmp);

list_add(&tmp->h.list, &((carlfw_desc_to_entry(prev))->h.list),
&((carlfw_desc_to_entry(next))->h.list));
return 0;
}

int carlfw_desc_add_before(struct carlfw *fw,
const struct carl9170fw_desc_head *desc,
struct carl9170fw_desc_head *pos)
{
struct carl9170fw_desc_head *prev;
struct carlfw_list_entry *prev_entry;

prev_entry = carlfw_desc_to_entry(pos);

prev = carlfw_entry_to_desc((struct carlfw_list_entry *) prev_entry->h.list.prev);

return carlfw_desc_add(fw, desc, prev, pos);
}

void carlfw_desc_unlink(struct carlfw *fw,
struct carl9170fw_desc_head *desc)
{
carlfw_entry_unlink(fw, carlfw_desc_to_entry(desc));
}

void carlfw_desc_del(struct carlfw *fw,
struct carl9170fw_desc_head *desc)
{
carlfw_entry_del(fw, carlfw_desc_to_entry(desc));
}

void *carlfw_desc_mod_len(struct carlfw *fw __unused,
struct carl9170fw_desc_head *desc, size_t len)
{
struct carlfw_list_entry *obj, tmp;
int new_len = le16_to_cpu(desc->length) + len;

if (new_len < (int)sizeof(*desc))
return ERR_PTR(-EINVAL);

if (new_len > CARL9170FW_DESC_MAX_LENGTH)
return ERR_PTR(-E2BIG);

obj = carlfw_desc_to_entry(desc);

memcpy(&tmp, obj, sizeof(tmp));
obj = realloc(obj, new_len + sizeof(struct carlfw_list_entry_head));
if (obj == NULL)
return ERR_PTR(-ENOMEM);

list_replace(&tmp.h.list, &obj->h.list);

desc = carlfw_entry_to_desc(obj);
desc->length = le16_to_cpu(new_len);
fw->desc_list_len += len;

return desc;
}

void *carlfw_desc_next(struct carlfw *fw,
struct carl9170fw_desc_head *pos)
{
struct carlfw_list_entry *entry;

if (!pos)
entry = (struct carlfw_list_entry *) &fw->desc_list;
else
entry = carlfw_desc_to_entry(pos);

if (list_at_tail(entry, &fw->desc_list, h.list))
return NULL;

entry = (struct carlfw_list_entry *) entry->h.list.next;

return carlfw_entry_to_desc(entry);
}

static int carlfw_parse_descs(struct carlfw *fw,
struct carl9170fw_otus_desc *otus_desc)
{
const struct carl9170fw_desc_head *iter = NULL;
int err;

carl9170fw_for_each_hdr(iter, &otus_desc->head) {
err = carlfw_desc_add_tail(fw, iter);
if (err)
return err;
}
/* LAST is added automatically by carlfw_store */

return err;
}

#if BYTE_ORDER == LITTLE_ENDIAN
#define CRCPOLY_LE 0xedb88320

/* copied from the linux kernel */
static uint32_t crc32_le(uint32_t crc, unsigned char const *p, size_t len)
{
int i;
while (len--) {
crc ^= *p++;
for (i = 0; i < 8; i++)
crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
}
return crc;
}
#else
#error "this tool does not work with a big endian host yet!"
#endif

static int carlfw_check_crc32s(struct carlfw *fw)
{
struct carl9170fw_chk_desc *chk_desc;
struct carlfw_list_entry *iter;
unsigned int elen;
uint32_t crc32;

chk_desc = carlfw_find_desc(fw, (uint8_t *) CHK_MAGIC,
sizeof(*chk_desc),
CARL9170FW_CHK_DESC_CUR_VER);
if (!chk_desc)
return -ENODATA;

crc32 = crc32_le(~0, (void *) fw->fw.data, fw->fw.len);
if (crc32 != le32_to_cpu(chk_desc->fw_crc32))
return -EINVAL;

carlfw_walk_descs(iter, fw) {
elen = le16_to_cpu(iter->head.length);

if (carl9170fw_desc_cmp(&iter->head, (uint8_t *) CHK_MAGIC,
sizeof(*chk_desc),
CARL9170FW_CHK_DESC_CUR_VER))
continue;

crc32 = crc32_le(crc32, (void *) &iter->head, elen);
}

if (crc32 != le32_to_cpu(chk_desc->hdr_crc32))
return -EINVAL;

return 0;
}

struct carlfw *carlfw_load(const char *basename)
{
char filename[256];
struct carlfw *fw;
struct carl9170fw_otus_desc *otus_desc;
struct carl9170fw_last_desc *last_desc;
struct carlfw_file *hdr_file;
unsigned long fin, diff, off, rem;
int err;

fw = calloc(1, sizeof(*fw));
if (!fw)
return ERR_PTR(-ENOMEM);

init_list_head(&fw->desc_list);

err = __carlfw_load(&fw->fw, basename, "r");
if (err)
goto err_out;

if (fw->hdr.name)
hdr_file = &fw->hdr;
else
hdr_file = &fw->fw;

otus_desc = __carlfw_find_desc(hdr_file, (uint8_t *) OTUS_MAGIC,
sizeof(*otus_desc),
CARL9170FW_OTUS_DESC_CUR_VER);
last_desc = __carlfw_find_desc(hdr_file, (uint8_t *) LAST_MAGIC,
sizeof(*last_desc),
CARL9170FW_LAST_DESC_CUR_VER);

if (!otus_desc || !last_desc ||
(unsigned long) otus_desc > (unsigned long) last_desc) {
err = -ENODATA;
goto err_out;
}

err = carlfw_parse_descs(fw, otus_desc);
if (err)
goto err_out;

fin = (unsigned long)last_desc + sizeof(*last_desc);
diff = fin - (unsigned long)otus_desc;
rem = hdr_file->len - (fin - (unsigned long) hdr_file->data);

if (rem) {
off = (unsigned long)otus_desc - (unsigned long)hdr_file->data;
memmove(&hdr_file->data[off],
((uint8_t *)last_desc) + sizeof(*last_desc), rem);
}

hdr_file->len -= diff;
hdr_file->data = realloc(hdr_file->data, hdr_file->len);
if (!hdr_file->data && hdr_file->len) {
err = -ENOMEM;
goto err_out;
}

err = carlfw_check_crc32s(fw);
if (err && err != -ENODATA)
goto err_out;

return fw;

err_out:
carlfw_release(fw);
return ERR_PTR(err);
}

static int carlfw_apply_checksums(struct carlfw *fw)
{
struct carlfw_list_entry *iter;
struct carl9170fw_chk_desc tmp = {
CARL9170FW_FILL_DESC(CHK_MAGIC, sizeof(tmp),
CARL9170FW_CHK_DESC_MIN_VER,
CARL9170FW_CHK_DESC_CUR_VER) };
struct carl9170fw_chk_desc *chk_desc = NULL;
int err = 0;
unsigned int len = 0, elen, max_len;
uint32_t crc32;

chk_desc = carlfw_find_desc(fw, (uint8_t *) CHK_MAGIC,
sizeof(*chk_desc),
CARL9170FW_CHK_DESC_CUR_VER);
if (chk_desc) {
carlfw_desc_del(fw, &chk_desc->head);
chk_desc = NULL;
}

max_len = fw->desc_list_len;

crc32 = crc32_le(~0, (void *) fw->fw.data, fw->fw.len);
tmp.fw_crc32 = cpu_to_le32(crc32);

/*
* NOTE:
*
* The descriptor checksum is seeded with the firmware's crc32.
* This neat trick ensures that the driver can check whenever
* descriptor actually belongs to the firmware, or not.
*/

carlfw_walk_descs(iter, fw) {
elen = le16_to_cpu(iter->head.length);

if (max_len < len + elen)
return -EMSGSIZE;

crc32 = crc32_le(crc32, (void *) &iter->head, elen);
len += elen;
}

tmp.hdr_crc32 = cpu_to_le32(crc32);

err = carlfw_desc_add_tail(fw, &tmp.head);

return err;
}

int carlfw_store(struct carlfw *fw)
{
struct carl9170fw_last_desc last_desc = {
CARL9170FW_FILL_DESC(LAST_MAGIC, sizeof(last_desc),
CARL9170FW_LAST_DESC_MIN_VER,
CARL9170FW_LAST_DESC_CUR_VER) };

struct carlfw_list_entry *iter;
FILE *fh;
int err, elen;

err = carlfw_apply_checksums(fw);
if (err)
return err;

fh = fopen(fw->fw.name, "w");
if (!fh)
return -errno;

err = fwrite(fw->fw.data, fw->fw.len, 1, fh);
if (err != 1) {
err = -errno;
goto close_out;
}

if (fw->hdr.name) {
fclose(fh);

fh = fopen(fw->hdr.name, "w");
}

carlfw_walk_descs(iter, fw) {
elen = le16_to_cpu(iter->head.length);

if (elen > CARL9170FW_DESC_MAX_LENGTH) {
err = -E2BIG;
goto close_out;
}

err = fwrite(iter->data, elen, 1, fh);
if (err != 1) {
err = -ferror(fh);
goto close_out;
}
}

err = fwrite(&last_desc, sizeof(last_desc), 1, fh);
if (err != 1) {
err = -ferror(fh);
goto close_out;
}

err = 0;

close_out:
fclose(fh);
return err;
}

void *carlfw_mod_tailroom(struct carlfw *fw, ssize_t len)
{
size_t new_len;
void *buf;

new_len = fw->fw.len + len;

if (!carl9170fw_size_check(new_len))
return ERR_PTR(-EINVAL);

buf = realloc(fw->fw.data, new_len);
if (buf == NULL)
return ERR_PTR(-ENOMEM);

fw->fw.len = new_len;
fw->fw.data = buf;
return &fw->fw.data[new_len - len];
}

void *carlfw_mod_headroom(struct carlfw *fw, ssize_t len)
{
size_t new_len;
void *ptr;

new_len = fw->fw.len + len;
if (!carl9170fw_size_check(new_len))
return ERR_PTR(-EINVAL);

if (len < 0)
memmove(fw->fw.data, &fw->fw.data[len], new_len);

ptr = carlfw_mod_tailroom(fw, len);
if (IS_ERR_OR_NULL(ptr))
return ptr;

if (len > 0)
memmove(&fw->fw.data[len], &fw->fw.data[0], new_len - len);

return fw->fw.data;
}

void *carlfw_get_fw(struct carlfw *fw, size_t *len)
{
*len = fw->fw.len;
return fw->fw.data;
}

unsigned int carlfw_get_descs_num(struct carlfw *fw)
{
return fw->desc_list_entries;
}

unsigned int carlfw_get_descs_size(struct carlfw *fw)
{
return fw->desc_list_len;
}