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- /* Copyright (c) 2017 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * @section DESCRIPTION
- *
- * Parser for the AT command syntax
- *
- */
- #include "ATCmdParser.h"
- #include "mbed_poll.h"
- #include "mbed_debug.h"
- #ifdef LF
- #undef LF
- #define LF 10
- #else
- #define LF 10
- #endif
- #ifdef CR
- #undef CR
- #define CR 13
- #else
- #define CR 13
- #endif
- // getc/putc handling with timeouts
- int ATCmdParser::putc(char c)
- {
- pollfh fhs;
- fhs.fh = _fh;
- fhs.events = POLLOUT;
- int count = poll(&fhs, 1, _timeout);
- if (count > 0 && (fhs.revents & POLLOUT)) {
- return _fh->write(&c, 1) == 1 ? 0 : -1;
- } else {
- return -1;
- }
- }
- int ATCmdParser::getc()
- {
- pollfh fhs;
- fhs.fh = _fh;
- fhs.events = POLLIN;
- int count = poll(&fhs, 1, _timeout);
- if (count > 0 && (fhs.revents & POLLIN)) {
- unsigned char ch;
- return _fh->read(&ch, 1) == 1 ? ch : -1;
- } else {
- return -1;
- }
- }
- void ATCmdParser::flush()
- {
- while (_fh->readable()) {
- unsigned char ch;
- _fh->read(&ch, 1);
- }
- }
- // read/write handling with timeouts
- int ATCmdParser::write(const char *data, int size)
- {
- int i = 0;
- for (; i < size; i++) {
- if (putc(data[i]) < 0) {
- return -1;
- }
- }
- return i;
- }
- int ATCmdParser::read(char *data, int size)
- {
- int i = 0;
- for (; i < size; i++) {
- int c = getc();
- if (c < 0) {
- return -1;
- }
- data[i] = c;
- }
- return i;
- }
- // printf/scanf handling
- int ATCmdParser::vprintf(const char *format, va_list args)
- {
- if (vsprintf(_buffer, format, args) < 0) {
- return false;
- }
- int i = 0;
- for (; _buffer[i]; i++) {
- if (putc(_buffer[i]) < 0) {
- return -1;
- }
- }
- return i;
- }
- int ATCmdParser::vscanf(const char *format, va_list args)
- {
- // Since format is const, we need to copy it into our buffer to
- // add the line's null terminator and clobber value-matches with asterisks.
- //
- // We just use the beginning of the buffer to avoid unnecessary allocations.
- int i = 0;
- int offset = 0;
- while (format[i]) {
- if (format[i] == '%' && format[i + 1] != '%' && format[i + 1] != '*') {
- _buffer[offset++] = '%';
- _buffer[offset++] = '*';
- i++;
- } else {
- _buffer[offset++] = format[i++];
- }
- }
- // Scanf has very poor support for catching errors
- // fortunately, we can abuse the %n specifier to determine
- // if the entire string was matched.
- _buffer[offset++] = '%';
- _buffer[offset++] = 'n';
- _buffer[offset++] = 0;
- // To workaround scanf's lack of error reporting, we actually
- // make two passes. One checks the validity with the modified
- // format string that only stores the matched characters (%n).
- // The other reads in the actual matched values.
- //
- // We keep trying the match until we succeed or some other error
- // derails us.
- int j = 0;
- while (true) {
- // Ran out of space
- if (j + 1 >= _buffer_size - offset) {
- return false;
- }
- // Receive next character
- int c = getc();
- if (c < 0) {
- return -1;
- }
- _buffer[offset + j++] = c;
- _buffer[offset + j] = 0;
- // Check for match
- int count = -1;
- sscanf(_buffer + offset, _buffer, &count);
- // We only succeed if all characters in the response are matched
- if (count == j) {
- // Store the found results
- vsscanf(_buffer + offset, format, args);
- return j;
- }
- }
- }
- // Command parsing with line handling
- bool ATCmdParser::vsend(const char *command, va_list args)
- {
- // Create and send command
- if (vsprintf(_buffer, command, args) < 0) {
- return false;
- }
- for (int i = 0; _buffer[i]; i++) {
- if (putc(_buffer[i]) < 0) {
- return false;
- }
- }
- // Finish with newline
- for (size_t i = 0; _output_delimiter[i]; i++) {
- if (putc(_output_delimiter[i]) < 0) {
- return false;
- }
- }
- debug_if(_dbg_on, "AT> %s\n", _buffer);
- return true;
- }
- bool ATCmdParser::vrecv(const char *response, va_list args)
- {
- restart:
- _aborted = false;
- // Iterate through each line in the expected response
- while (response[0]) {
- // Since response is const, we need to copy it into our buffer to
- // add the line's null terminator and clobber value-matches with asterisks.
- //
- // We just use the beginning of the buffer to avoid unnecessary allocations.
- int i = 0;
- int offset = 0;
- bool whole_line_wanted = false;
- while (response[i]) {
- if (response[i] == '%' && response[i + 1] != '%' && response[i + 1] != '*') {
- _buffer[offset++] = '%';
- _buffer[offset++] = '*';
- i++;
- } else {
- _buffer[offset++] = response[i++];
- // Find linebreaks, taking care not to be fooled if they're in a %[^\n] conversion specification
- if (response[i - 1] == '\n' && !(i >= 3 && response[i - 3] == '[' && response[i - 2] == '^')) {
- whole_line_wanted = true;
- break;
- }
- }
- }
- // Scanf has very poor support for catching errors
- // fortunately, we can abuse the %n specifier to determine
- // if the entire string was matched.
- _buffer[offset++] = '%';
- _buffer[offset++] = 'n';
- _buffer[offset++] = 0;
- debug_if(_dbg_on, "AT? %s\n", _buffer);
- // To workaround scanf's lack of error reporting, we actually
- // make two passes. One checks the validity with the modified
- // format string that only stores the matched characters (%n).
- // The other reads in the actual matched values.
- //
- // We keep trying the match until we succeed or some other error
- // derails us.
- int j = 0;
- while (true) {
- // Receive next character
- int c = getc();
- if (c < 0) {
- debug_if(_dbg_on, "AT(Timeout)\n");
- return false;
- }
- // Simplify newlines (borrowed from retarget.cpp)
- if ((c == CR && _in_prev != LF) ||
- (c == LF && _in_prev != CR)) {
- _in_prev = c;
- c = '\n';
- } else if ((c == CR && _in_prev == LF) ||
- (c == LF && _in_prev == CR)) {
- _in_prev = c;
- // onto next character
- continue;
- } else {
- _in_prev = c;
- }
- _buffer[offset + j++] = c;
- _buffer[offset + j] = 0;
- // Check for oob data
- for (struct oob *oob = _oobs; oob; oob = oob->next) {
- if ((unsigned)j == oob->len && memcmp(
- oob->prefix, _buffer + offset, oob->len) == 0) {
- debug_if(_dbg_on, "AT! %s\n", oob->prefix);
- oob->cb();
- if (_aborted) {
- debug_if(_dbg_on, "AT(Aborted)\n");
- return false;
- }
- // oob may have corrupted non-reentrant buffer,
- // so we need to set it up again
- goto restart;
- }
- }
- // Check for match
- int count = -1;
- if (whole_line_wanted && c != '\n') {
- // Don't attempt scanning until we get delimiter if they included it in format
- // This allows recv("Foo: %s\n") to work, and not match with just the first character of a string
- // (scanf does not itself match whitespace in its format string, so \n is not significant to it)
- } else {
- sscanf(_buffer + offset, _buffer, &count);
- }
- // We only succeed if all characters in the response are matched
- if (count == j) {
- debug_if(_dbg_on, "AT= %s\n", _buffer + offset);
- // Reuse the front end of the buffer
- memcpy(_buffer, response, i);
- _buffer[i] = 0;
- // Store the found results
- vsscanf(_buffer + offset, _buffer, args);
- // Jump to next line and continue parsing
- response += i;
- break;
- }
- // Clear the buffer when we hit a newline or ran out of space
- // running out of space usually means we ran into binary data
- if (c == '\n' || j + 1 >= _buffer_size - offset) {
- debug_if(_dbg_on, "AT< %s", _buffer + offset);
- j = 0;
- }
- }
- }
- return true;
- }
- // Mapping to vararg functions
- int ATCmdParser::printf(const char *format, ...)
- {
- va_list args;
- va_start(args, format);
- int res = vprintf(format, args);
- va_end(args);
- return res;
- }
- int ATCmdParser::scanf(const char *format, ...)
- {
- va_list args;
- va_start(args, format);
- int res = vscanf(format, args);
- va_end(args);
- return res;
- }
- bool ATCmdParser::send(const char *command, ...)
- {
- va_list args;
- va_start(args, command);
- bool res = vsend(command, args);
- va_end(args);
- return res;
- }
- bool ATCmdParser::recv(const char *response, ...)
- {
- va_list args;
- va_start(args, response);
- bool res = vrecv(response, args);
- va_end(args);
- return res;
- }
- // oob registration
- void ATCmdParser::oob(const char *prefix, Callback<void()> cb)
- {
- struct oob *oob = new struct oob;
- oob->len = strlen(prefix);
- oob->prefix = prefix;
- oob->cb = cb;
- oob->next = _oobs;
- _oobs = oob;
- }
- void ATCmdParser::abort()
- {
- _aborted = true;
- }
- bool ATCmdParser::process_oob()
- {
- if (!_fh->readable()) {
- return false;
- }
- int i = 0;
- while (true) {
- // Receive next character
- int c = getc();
- if (c < 0) {
- return false;
- }
- // Simplify newlines (borrowed from retarget.cpp)
- if ((c == CR && _in_prev != LF) ||
- (c == LF && _in_prev != CR)) {
- _in_prev = c;
- c = '\n';
- } else if ((c == CR && _in_prev == LF) ||
- (c == LF && _in_prev == CR)) {
- _in_prev = c;
- // onto next character
- continue;
- } else {
- _in_prev = c;
- }
- _buffer[i++] = c;
- _buffer[i] = 0;
- // Check for oob data
- struct oob *oob = _oobs;
- while (oob) {
- if (i == (int)oob->len && memcmp(
- oob->prefix, _buffer, oob->len) == 0) {
- debug_if(_dbg_on, "AT! %s\r\n", oob->prefix);
- oob->cb();
- return true;
- }
- oob = oob->next;
- }
- // Clear the buffer when we hit a newline or ran out of space
- // running out of space usually means we ran into binary data
- if (((i + 1) >= _buffer_size) || (c == '\n')) {
- debug_if(_dbg_on, "AT< %s", _buffer);
- i = 0;
- }
- }
- }
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