circuitpython/shared-module/os/getenv.c

431 lines
14 KiB
C

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* SPDX-FileCopyrightText: Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
// These functions are separate from __init__.c so that os.getenv() can be
// tested in the unix "coverage" build, without bringing in "our" os module
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include "shared-bindings/os/__init__.h"
#include "shared-module/os/__init__.h"
#include "py/gc.h"
#include "py/misc.h"
#include "py/mpstate.h"
#include "py/mpprint.h"
#include "py/objstr.h"
#include "py/parsenum.h"
#include "py/runtime.h"
#include "supervisor/filesystem.h"
#define GETENV_PATH "/settings.toml"
#include "extmod/vfs.h"
#include "extmod/vfs_fat.h"
typedef FIL file_arg;
STATIC bool open_file(const char *name, file_arg *active_file) {
#if defined(UNIX)
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
mp_obj_t file_obj = mp_call_function_2(MP_OBJ_FROM_PTR(&mp_builtin_open_obj), mp_obj_new_str(name, strlen(name)), MP_ROM_QSTR(MP_QSTR_rb));
mp_arg_validate_type(file_obj, &mp_type_vfs_fat_fileio, MP_QSTR_file);
pyb_file_obj_t *file = MP_OBJ_TO_PTR(file_obj);
*active_file = file->fp;
nlr_pop();
return true;
} else {
return false;
}
#else
FATFS *fs = filesystem_circuitpy();
FRESULT result = f_open(fs, active_file, name, FA_READ);
return result == FR_OK;
#endif
}
STATIC void close_file(file_arg *active_file) {
// nothing
}
STATIC bool is_eof(file_arg *active_file) {
return f_eof(active_file) || f_error(active_file);
}
// Return 0 if there is no next character (EOF).
STATIC uint8_t get_next_byte(FIL *active_file) {
uint8_t character = 0;
UINT quantity_read;
// If there's an error or quantity_read is 0, character will remain 0.
f_read(active_file, &character, 1, &quantity_read);
return character;
}
STATIC void seek_eof(file_arg *active_file) {
f_lseek(active_file, f_size(active_file));
}
// For a fixed buffer, record the required size rather than throwing
STATIC void vstr_add_byte_nonstd(vstr_t *vstr, byte b) {
if (!vstr->fixed_buf || vstr->alloc > vstr->len) {
vstr_add_byte(vstr, b);
} else {
vstr->len++;
}
}
// For a fixed buffer, record the required size rather than throwing
STATIC void vstr_add_char_nonstd(vstr_t *vstr, unichar c) {
size_t ulen =
(c < 0x80) ? 1 :
(c < 0x800) ? 2 :
(c < 0x10000) ? 3 : 4;
if (!vstr->fixed_buf || vstr->alloc > vstr->len + ulen) {
vstr_add_char(vstr, c);
} else {
vstr->len += ulen;
}
}
STATIC void next_line(file_arg *active_file) {
uint8_t character;
do {
character = get_next_byte(active_file);
} while (character != 0 && character != '\n');
}
// Discard whitespace, except for newlines, returning the next character after the whitespace.
// Return 0 if there is no next character (EOF).
STATIC uint8_t consume_whitespace(file_arg *active_file) {
uint8_t character;
do {
character = get_next_byte(active_file);
} while (character != '\n' && character != 0 && unichar_isspace(character));
return character;
}
// Starting at the start of a new line, determines if the key matches the given
// key.
//
// If result is true, the key matches and file pointer is pointing just after the "=".
// If the result is false, the key does NOT match and the file pointer is
// pointing at the start of the next line, if any
STATIC bool key_matches(file_arg *active_file, const char *key) {
uint8_t character;
character = consume_whitespace(active_file);
if (character == '[' || character == 0) {
seek_eof(active_file);
return false;
}
while (*key) {
if (character != *key++) {
// A character didn't match the key, so it's not a match
// If the non-matching char was not the end of the line,
// then consume the rest of the line
if (character != '\n') {
next_line(active_file);
}
return false;
}
character = get_next_byte(active_file);
}
// the next character could be whitespace; consume if necessary
if (unichar_isspace(character)) {
character = consume_whitespace(active_file);
}
// If we're not looking at the "=" then the key didn't match
if (character != '=') {
// A character didn't match the key, so it's not a match
// If the non-matching char was not the end of the line,
// then consume the rest of the line
if (character != '\n') {
next_line(active_file);
}
return false;
}
return true;
}
STATIC os_getenv_err_t read_unicode_escape(file_arg *active_file, int sz, vstr_t *buf) {
char hex_buf[sz + 1];
for (int i = 0; i < sz; i++) {
hex_buf[i] = get_next_byte(active_file);
}
hex_buf[sz] = 0;
char *end;
unsigned long c = strtoul(hex_buf, &end, 16);
if (end != &hex_buf[sz]) {
return GETENV_ERR_UNEXPECTED | *end;
}
if (c >= 0x110000) {
return GETENV_ERR_UNICODE;
}
vstr_add_char_nonstd(buf, c);
return GETENV_OK;
}
// Read a quoted string
STATIC os_getenv_err_t read_string_value(file_arg *active_file, vstr_t *buf) {
while (true) {
int character = get_next_byte(active_file);
switch (character) {
case 0:
case '\n':
return GETENV_ERR_UNEXPECTED | character;
case '"':
character = consume_whitespace(active_file);
switch (character) {
case '#':
next_line(active_file);
MP_FALLTHROUGH;
case 0:
case '\n':
return GETENV_OK;
default:
return GETENV_ERR_UNEXPECTED | character;
}
case '\\':
character = get_next_byte(active_file);
switch (character) {
case 0:
case '\n':
return GETENV_ERR_UNEXPECTED | character;
case 'b':
character = '\b';
break;
case 'r':
character = '\r';
break;
case 'n':
character = '\n';
break;
case 't':
character = '\t';
break;
case 'v':
character = '\v';
break;
case 'f':
character = '\f';
break;
case 'U':
case 'u': {
int sz = (character == 'u') ? 4 : 8;
os_getenv_err_t res;
res = read_unicode_escape(active_file, sz, buf);
if (res != GETENV_OK) {
return res;
}
continue;
}
// default falls through, other escaped characters
// represent themselves
}
MP_FALLTHROUGH;
default:
vstr_add_byte_nonstd(buf, character);
}
}
}
// Read a numeric value (non-quoted value) as a string
STATIC os_getenv_err_t read_bare_value(file_arg *active_file, vstr_t *buf, int first_character) {
int character = first_character;
while (true) {
switch (character) {
case 0:
case '\n':
return GETENV_OK;
case '#':
next_line(active_file);
return GETENV_OK;
default:
vstr_add_byte_nonstd(buf, character);
}
character = get_next_byte(active_file);
}
}
STATIC mp_int_t read_value(file_arg *active_file, vstr_t *buf, bool *quoted) {
uint8_t character;
character = consume_whitespace(active_file);
*quoted = (character == '"');
if (*quoted) {
return read_string_value(active_file, buf);
} else {
return read_bare_value(active_file, buf, character);
}
}
STATIC os_getenv_err_t os_getenv_vstr(const char *path, const char *key, vstr_t *buf, bool *quoted) {
file_arg active_file;
if (!open_file(path, &active_file)) {
return GETENV_ERR_OPEN;
}
os_getenv_err_t result = GETENV_ERR_NOT_FOUND;
while (!is_eof(&active_file)) {
if (key_matches(&active_file, key)) {
result = read_value(&active_file, buf, quoted);
break;
}
}
close_file(&active_file);
return result;
}
STATIC os_getenv_err_t os_getenv_buf_terminated(const char *key, char *value, size_t value_len, bool *quoted) {
vstr_t buf;
vstr_init_fixed_buf(&buf, value_len, value);
os_getenv_err_t result = os_getenv_vstr(GETENV_PATH, key, &buf, quoted);
if (result == GETENV_OK) {
vstr_add_byte_nonstd(&buf, 0);
memcpy(value, buf.buf, MIN(buf.len, value_len));
if (buf.len > value_len) { // this length includes trailing NUL
result = GETENV_ERR_LENGTH;
}
}
return result;
}
STATIC void print_dont_raise(const mp_obj_type_t *exc_type, mp_rom_error_text_t fmt, ...) {
va_list argptr;
va_start(argptr, fmt);
mp_vcprintf(&mp_plat_print, fmt, argptr);
mp_printf(&mp_plat_print, "\n");
va_end(argptr);
}
STATIC void handle_getenv_error(os_getenv_err_t error, void (*handle)(const mp_obj_type_t *exc_type, mp_rom_error_text_t fmt, ...)) {
if (error == GETENV_OK) {
return;
}
if (error & GETENV_ERR_UNEXPECTED) {
byte character = (error & 0xff);
char buf[8];
vstr_t vstr;
vstr_init_fixed_buf(&vstr, sizeof(buf), buf);
mp_print_t print = { .data = &vstr, .print_strn = (mp_print_strn_t)vstr_add_strn };
if (character) {
mp_str_print_quoted(&print, &character, 1, true);
} else {
mp_str_print_quoted(&print, (byte *)"EOF", 3, true);
}
handle(&mp_type_ValueError, MP_ERROR_TEXT("Invalid byte %.*s"), vstr.len, vstr.buf);
} else {
switch (error) {
case GETENV_ERR_OPEN:
handle(&mp_type_ValueError, MP_ERROR_TEXT("%S"), MP_ERROR_TEXT("File not found"));
break;
case GETENV_ERR_UNICODE:
handle(&mp_type_ValueError, MP_ERROR_TEXT("%S"), MP_ERROR_TEXT("Invalid unicode escape"));
break;
case GETENV_ERR_NOT_FOUND:
handle(&mp_type_ValueError, MP_ERROR_TEXT("%S"), MP_ERROR_TEXT("Key not found"));
break;
default:
handle(&mp_type_RuntimeError, MP_ERROR_TEXT("%S"), MP_ERROR_TEXT("Internal error"));
break;
}
}
}
STATIC void common_hal_os_getenv_showerr(const char *key, os_getenv_err_t result) {
if (result != GETENV_OK && result != GETENV_ERR_OPEN && result != GETENV_ERR_NOT_FOUND) {
mp_cprintf(&mp_plat_print, MP_ERROR_TEXT("An error occurred while retrieving '%s':\n"), key);
handle_getenv_error(result, print_dont_raise);
}
}
STATIC
os_getenv_err_t common_hal_os_getenv_str_inner(const char *key, char *value, size_t value_len) {
bool quoted;
os_getenv_err_t result = os_getenv_buf_terminated(key, value, value_len, &quoted);
if (result == GETENV_OK && !quoted) {
result = GETENV_ERR_UNEXPECTED | value[0];
}
return result;
}
os_getenv_err_t common_hal_os_getenv_str(const char *key, char *value, size_t value_len) {
os_getenv_err_t result = common_hal_os_getenv_str_inner(key, value, value_len);
common_hal_os_getenv_showerr(key, result);
return result;
}
mp_obj_t common_hal_os_getenv_path(const char *path, const char *key, mp_obj_t default_) {
vstr_t buf;
bool quoted;
vstr_init(&buf, 64);
os_getenv_err_t result = os_getenv_vstr(path, key, &buf, &quoted);
if (result == GETENV_ERR_NOT_FOUND || result == GETENV_ERR_OPEN) {
return default_;
}
handle_getenv_error(result, mp_raise_msg_varg);
if (quoted) {
return mp_obj_new_str_from_vstr(&buf);
} else {
return mp_parse_num_integer(buf.buf, buf.len, 0, NULL);
}
}
mp_obj_t common_hal_os_getenv(const char *key, mp_obj_t default_) {
return common_hal_os_getenv_path(GETENV_PATH, key, default_);
}
STATIC os_getenv_err_t common_hal_os_getenv_int_inner(const char *key, mp_int_t *value) {
char buf[16];
bool quoted;
os_getenv_err_t result = os_getenv_buf_terminated(key, buf, sizeof(buf), &quoted);
if (result != GETENV_OK) {
return result;
}
if (quoted) {
return GETENV_ERR_UNEXPECTED | '"';
}
char *end;
long num = strtol(buf, &end, 0);
while (unichar_isspace(*end)) {
end++;
}
if (end == buf || *end) { // If the whole buffer was not consumed it's an error
return GETENV_ERR_UNEXPECTED | *end;
}
*value = (mp_int_t)num;
return GETENV_OK;
}
os_getenv_err_t common_hal_os_getenv_int(const char *key, mp_int_t *value) {
os_getenv_err_t result = common_hal_os_getenv_int_inner(key, value);
common_hal_os_getenv_showerr(key, result);
return result;
}