ardupilot/libraries/AP_Filesystem/AP_Filesystem_Param.cpp

591 lines
16 KiB
C++

/*
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, either version 3 of the License, or
(at your option) any later version.
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, see <http://www.gnu.org/licenses/>.
*/
/*
ArduPilot filesystem interface for parameters
*/
#include "AP_Filesystem.h"
#include "AP_Filesystem_Param.h"
#include <AP_Param/AP_Param.h>
#include <AP_Math/AP_Math.h>
#include <ctype.h>
#define PACKED_NAME "param.pck"
extern const AP_HAL::HAL& hal;
extern int errno;
int AP_Filesystem_Param::open(const char *fname, int flags)
{
if (!check_file_name(fname)) {
errno = ENOENT;
return -1;
}
bool read_only = ((flags & O_ACCMODE) == O_RDONLY);
uint8_t idx;
for (idx=0; idx<max_open_file; idx++) {
if (!file[idx].open) {
break;
}
}
if (idx == max_open_file) {
errno = ENFILE;
return -1;
}
struct rfile &r = file[idx];
if (read_only) {
r.cursors = new cursor[num_cursors];
if (r.cursors == nullptr) {
errno = ENOMEM;
return -1;
}
}
r.file_ofs = 0;
r.open = true;
r.start = 0;
r.count = 0;
r.read_size = 0;
r.writebuf = nullptr;
if (!read_only) {
// setup for upload
r.writebuf = new ExpandingString();
if (r.writebuf == nullptr) {
close(idx);
errno = ENOMEM;
return -1;
}
}
/*
allow for URI style arguments param.pck?start=N&count=C
*/
const char *c = strchr(fname, '?');
while (c && *c) {
c++;
if (strncmp(c, "start=", 6) == 0) {
uint32_t v = strtoul(c+6, nullptr, 10);
if (v >= UINT16_MAX) {
goto failed;
}
r.start = v;
c += 6;
c = strchr(c, '&');
continue;
}
if (strncmp(c, "count=", 6) == 0) {
uint32_t v = strtoul(c+6, nullptr, 10);
if (v >= UINT16_MAX) {
goto failed;
}
r.count = v;
c += 6;
c = strchr(c, '&');
continue;
}
}
return idx;
failed:
delete [] r.cursors;
r.open = false;
errno = EINVAL;
return -1;
}
int AP_Filesystem_Param::close(int fd)
{
if (fd < 0 || fd >= max_open_file || !file[fd].open) {
errno = EBADF;
return -1;
}
struct rfile &r = file[fd];
int ret = 0;
if (r.writebuf != nullptr && !finish_upload(r)) {
errno = EINVAL;
ret = -1;
}
r.open = false;
delete [] r.cursors;
r.cursors = nullptr;
delete r.writebuf;
r.writebuf = nullptr;
return ret;
}
/*
packed format:
file header:
uint16_t magic = 0x671b
uint16_t num_params
uint16_t total_params
per-parameter:
uint8_t type:4; // AP_Param type NONE=0, INT8=1, INT16=2, INT32=3, FLOAT=4
uint8_t flags:4; // for future use
uint8_t common_len:4; // number of name bytes in common with previous entry, 0..15
uint8_t name_len:4; // non-common length of param name -1 (0..15)
uint8_t name[name_len]; // name
uint8_t data[]; // value, length given by variable type
Any leading zero bytes after the header should be discarded as pad
bytes. Pad bytes are used to ensure that a parameter data[] field
does not cross a read packet boundary
*/
/*
pack a single parameter. The buffer must be at least of size max_pack_len
*/
uint8_t AP_Filesystem_Param::pack_param(const struct rfile &r, struct cursor &c, uint8_t *buf)
{
char name[AP_MAX_NAME_SIZE+1];
name[AP_MAX_NAME_SIZE] = 0;
enum ap_var_type ptype;
AP_Param *ap;
if (c.token_ofs == 0) {
c.idx = 0;
ap = AP_Param::first(&c.token, &ptype);
uint16_t idx = 0;
while (idx < r.start && ap) {
ap = AP_Param::next_scalar(&c.token, &ptype);
idx++;
}
} else {
c.idx++;
ap = AP_Param::next_scalar(&c.token, &ptype);
}
if (ap == nullptr || (r.count && c.idx >= r.count)) {
return 0;
}
ap->copy_name_token(c.token, name, AP_MAX_NAME_SIZE, true);
uint8_t common_len = 0;
const char *last_name = c.last_name;
const char *pname = name;
while (*pname == *last_name && *pname) {
common_len++;
pname++;
last_name++;
}
const uint8_t name_len = strlen(pname);
const uint8_t type_len = AP_Param::type_size(ptype);
uint8_t packed_len = type_len + name_len + 2;
const uint8_t flags = 0;
/*
see if we need to add padding to ensure that a data field never
crosses a block boundary. This ensures that re-reading a block
won't get a corrupt value for a parameter
*/
if (type_len > 1) {
const uint32_t ofs = c.token_ofs + sizeof(struct header) + packed_len;
const uint32_t ofs_mod = ofs % r.read_size;
if (ofs_mod > 0 && ofs_mod < type_len) {
const uint8_t pad = type_len - ofs_mod;
memset(buf, 0, pad);
buf += pad;
packed_len += pad;
}
}
buf[0] = uint8_t(ptype) | (flags<<4);
buf[1] = common_len | ((name_len-1)<<4);
memcpy(&buf[2], pname, name_len);
memcpy(&buf[2+name_len], ap, type_len);
strcpy(c.last_name, name);
return packed_len;
}
/*
seek the token to match file offset
*/
bool AP_Filesystem_Param::token_seek(const struct rfile &r, const uint32_t data_ofs, struct cursor &c)
{
if (data_ofs == 0) {
memset(&c, 0, sizeof(c));
return true;
}
if (c.token_ofs > data_ofs) {
memset(&c, 0, sizeof(c));
}
if (c.trailer_len > 0) {
uint8_t n = MIN(c.trailer_len, data_ofs - c.token_ofs);
if (n != c.trailer_len) {
memmove(&c.trailer[0], &c.trailer[n], c.trailer_len - n);
}
c.trailer_len -= n;
c.token_ofs += n;
}
while (data_ofs != c.token_ofs) {
uint32_t available = data_ofs - c.token_ofs;
uint8_t tbuf[max_pack_len];
uint8_t len = pack_param(r, c, tbuf);
if (len == 0) {
// no more parameters
break;
}
uint8_t n = MIN(len, available);
if (len > available) {
c.trailer_len = len - available;
memcpy(c.trailer, &tbuf[n], c.trailer_len);
}
c.token_ofs += n;
}
return data_ofs == c.token_ofs;
}
int32_t AP_Filesystem_Param::read(int fd, void *buf, uint32_t count)
{
if (fd < 0 || fd >= max_open_file || !file[fd].open) {
errno = EBADF;
return -1;
}
struct rfile &r = file[fd];
if (r.writebuf != nullptr) {
// no read on upload
errno = EINVAL;
return -1;
}
size_t header_total = 0;
/*
we only allow for a single read size. This ensures that pad
bytes placed to avoid a data value crossing a block boundary in
the ftp protocol do not change when filling in lost packets
*/
if (r.read_size == 0 && count > 0) {
r.read_size = count;
}
if (r.read_size != 0 && r.read_size != count) {
errno = EINVAL;
return -1;
}
if (r.file_size != 0) {
// ensure we don't try to read past EOF
if (r.file_ofs > r.file_size) {
count = 0;
} else {
count = MIN(count, r.file_size - r.file_ofs);
}
}
if (r.file_ofs < sizeof(struct header)) {
struct header hdr;
hdr.total_params = AP_Param::count_parameters();
if (hdr.total_params <= r.start) {
errno = EINVAL;
return -1;
}
hdr.num_params = hdr.total_params - r.start;
if (r.count > 0 && hdr.num_params > r.count) {
hdr.num_params = r.count;
}
uint8_t n = MIN(sizeof(hdr) - r.file_ofs, count);
const uint8_t *b = (const uint8_t *)&hdr;
memcpy(buf, &b[r.file_ofs], n);
count -= n;
header_total += n;
r.file_ofs += n;
buf = (void *)(n + (const uint8_t *)buf);
if (count == 0) {
return header_total;
}
}
uint32_t data_ofs = r.file_ofs - sizeof(struct header);
uint8_t best_i = 0;
uint32_t best_ofs = r.cursors[0].token_ofs;
size_t total = 0;
// find the first cursor that is positioned after the file offset
for (uint8_t i=1; i<num_cursors; i++) {
struct cursor &c = r.cursors[i];
if (c.token_ofs >= data_ofs && c.token_ofs < best_ofs) {
best_i = i;
best_ofs = c.token_ofs;
}
}
struct cursor &c = r.cursors[best_i];
if (data_ofs != c.token_ofs) {
if (!token_seek(r, data_ofs, c)) {
// must be EOF
return header_total;
}
}
if (count == 0) {
return header_total;
}
uint8_t *ubuf = (uint8_t *)buf;
if (c.trailer_len > 0) {
uint8_t n = MIN(c.trailer_len, count);
memcpy(ubuf, c.trailer, n);
count -= n;
ubuf += n;
if (n != c.trailer_len) {
memmove(&c.trailer[0], &c.trailer[n], c.trailer_len - n);
}
c.trailer_len -= n;
total += n;
c.token_ofs += n;
}
while (count > 0) {
uint8_t tbuf[max_pack_len];
uint8_t len = pack_param(r, c, tbuf);
if (len == 0) {
// no more params, use this to trigger EOF in later reads
const uint32_t size = r.file_ofs + total;
if (r.file_size == 0) {
r.file_size = size;
} else {
r.file_size = MIN(size, r.file_size);
}
break;
}
uint8_t n = MIN(len, count);
if (len > count) {
c.trailer_len = len - count;
memcpy(c.trailer, &tbuf[count], c.trailer_len);
}
memcpy(ubuf, tbuf, n);
count -= n;
ubuf += n;
total += n;
c.token_ofs += n;
}
r.file_ofs += total;
return total + header_total;
}
int32_t AP_Filesystem_Param::lseek(int fd, int32_t offset, int seek_from)
{
if (fd < 0 || fd >= max_open_file || !file[fd].open) {
errno = EBADF;
return -1;
}
struct rfile &r = file[fd];
switch (seek_from) {
case SEEK_SET:
r.file_ofs = offset;
break;
case SEEK_CUR:
r.file_ofs += offset;
break;
case SEEK_END:
errno = EINVAL;
return -1;
}
return r.file_ofs;
}
int AP_Filesystem_Param::stat(const char *name, struct stat *stbuf)
{
if (!check_file_name(name)) {
errno = ENOENT;
return -1;
}
memset(stbuf, 0, sizeof(*stbuf));
// give fixed size to avoid needing to scan entire file
stbuf->st_size = 1024*1024;
return 0;
}
/*
check for the right file name
*/
bool AP_Filesystem_Param::check_file_name(const char *name)
{
const uint8_t packed_len = strlen(PACKED_NAME);
if (strncmp(name, PACKED_NAME, packed_len) == 0 &&
(name[packed_len] == 0 || name[packed_len] == '?')) {
return true;
}
return false;
}
/*
support param upload
*/
int32_t AP_Filesystem_Param::write(int fd, const void *buf, uint32_t count)
{
if (fd < 0 || fd >= max_open_file || !file[fd].open) {
errno = EBADF;
return -1;
}
struct rfile &r = file[fd];
if (r.writebuf == nullptr) {
errno = EBADF;
return -1;
}
struct header hdr;
if (r.file_ofs == 0 && count >= sizeof(hdr)) {
// pre-expand the buffer to the full size when we get the header
memcpy(&hdr, buf, sizeof(hdr));
if (hdr.magic == pmagic) {
const uint32_t flen = hdr.total_params;
if (flen > r.writebuf->get_length()) {
if (!r.writebuf->append(nullptr, flen - r.writebuf->get_length())) {
// not enough memory
return -1;
}
}
}
}
if (r.file_ofs + count > r.writebuf->get_length()) {
if (!r.writebuf->append(nullptr, r.file_ofs + count - r.writebuf->get_length())) {
return -1;
}
}
uint8_t *b = (uint8_t *)r.writebuf->get_writeable_string();
memcpy(&b[r.file_ofs], buf, count);
r.file_ofs += count;
return count;
}
/*
parse incoming parameters
*/
bool AP_Filesystem_Param::param_upload_parse(const rfile &r, bool &need_retry)
{
need_retry = false;
const uint8_t *b = (const uint8_t *)r.writebuf->get_string();
uint32_t length = r.writebuf->get_length();
struct header hdr;
if (length < sizeof(hdr)) {
return false;
}
memcpy(&hdr, b, sizeof(hdr));
if (hdr.magic != pmagic) {
return false;
}
if (length != hdr.total_params) {
return false;
}
b += sizeof(hdr);
char last_name[17] {};
for (uint16_t i=0; i<hdr.num_params; i++) {
enum ap_var_type ptype = (enum ap_var_type)(b[0]&0x0F);
uint8_t flags = (enum ap_var_type)(b[0]>>4);
if (flags != 0) {
return false;
}
uint8_t common_len = b[1]&0xF;
uint8_t name_len = (b[1]>>4)+1;
if (common_len + name_len > 16) {
return false;
}
char name[17];
memcpy(name, last_name, common_len);
memcpy(&name[common_len], &b[2], name_len);
name[common_len+name_len] = 0;
memcpy(last_name, name, sizeof(name));
enum ap_var_type ptype2 = AP_PARAM_NONE;
uint16_t flags2;
b += 2 + name_len;
AP_Param *p = AP_Param::find(name, &ptype2, &flags2);
if (p == nullptr) {
if (ptype == AP_PARAM_INT8) {
b++;
} else if (ptype == AP_PARAM_INT16) {
b += 2;
} else {
b += 4;
}
continue;
}
/*
if we are enabling a subsystem we need a small delay between
parameters to allow main thread to perform any allocation of
backends
*/
bool need_delay = ((flags2 & AP_PARAM_FLAG_ENABLE) != 0 &&
ptype2 == AP_PARAM_INT8 &&
((AP_Int8 *)p)->get() == 0);
if (ptype == ptype2 && ptype == AP_PARAM_INT32) {
// special handling of int32_t to preserve all bits
int32_t v;
memcpy(&v, b, sizeof(v));
((AP_Int32 *)p)->set(v);
b += 4;
} else if (ptype == AP_PARAM_INT8) {
if (need_delay && b[0] == 0) {
need_delay = false;
}
p->set_float((int8_t)b[0], ptype2);
b += 1;
} else if (ptype == AP_PARAM_INT16) {
int16_t v;
memcpy(&v, b, sizeof(v));
p->set_float(float(v), ptype2);
b += 2;
} else if (ptype == AP_PARAM_INT32) {
int32_t v;
memcpy(&v, b, sizeof(v));
p->set_float(float(v), ptype2);
b += 4;
} else if (ptype == AP_PARAM_FLOAT) {
float v;
memcpy(&v, b, sizeof(v));
p->set_float(v, ptype2);
b += 4;
}
p->save_sync(false, false);
if (need_delay) {
// let main thread have some time to init backends
need_retry = true;
hal.scheduler->delay(100);
}
}
return true;
}
/*
parse incoming parameters
*/
bool AP_Filesystem_Param::finish_upload(const rfile &r)
{
uint8_t loops = 0;
while (loops++ < 4) {
bool need_retry;
if (!param_upload_parse(r, need_retry)) {
return false;
}
if (!need_retry) {
break;
}
}
return true;
}