spz-lab4/src/cli.c

#include "macro.h"
#include "config.h"

#include "cli.h"
#include "print.h"

#include "fs.h"
#include "ctrl.h"

#include <stdlib.h>
#include <string.h>


static const struct CliCommandEntry cmd[] = {
	// mandatory commands
	{"mkfs", 1, (enum CliArgType[]) {INT}, fs_mkfs},
	{"create", 1, (enum CliArgType[]) {STR}, fs_create},

	// custom commands
	{"use", 1, (enum CliArgType[]) {STR}, fs_use},
	{"prohibit-write", 0, NULL, fs_prohibit_write},
	{"allow-write", 0, NULL, fs_allow_write},
	{"exit", 0, NULL, ctrl_exit}
};


static void destroy_tokenized_line(char **tokenized_line)
{
	for (int j = 0; j < CLI_MAX_ACCEPTED_ARGS; j++)
		if (tokenized_line[j])
			free(tokenized_line[j]);

	free(tokenized_line);
}

static int tokenized_line_len(char **t)
{
	int i;

	for (i = 0; i < CLI_MAX_ACCEPTED_ARGS; i++)
		if (!t[i])
			break;

	return i;
}

static char **tokenize_line(char *line, ssize_t result)
{
	if (result > CLI_MAX_LINE_LENGTH) {
		pr_err("command too long (%d > %d)\n", result+1, CLI_MAX_LINE_LENGTH);
		return NULL;
	}

	char **tokenized_line = malloc(sizeof(char *) * CLI_MAX_ACCEPTED_ARGS);
	memset(tokenized_line, 0, sizeof(char *) * CLI_MAX_ACCEPTED_ARGS);

	unsigned int i, t, l;
	for (
		i = 0, t = 0, l = 0;
		i < CLI_MAX_LINE_LENGTH,
		t <= CLI_MAX_ACCEPTED_ARGS,
		l < CLI_MAX_TOKEN_LENGTH;
		i++
	) {
		if (line[i] == '\n') {
			if (l) {
				if (t == CLI_MAX_ACCEPTED_ARGS) {
					t++;
					break;
				}

				tokenized_line[t] = malloc(sizeof(char) * (l+1));
				memcpy(tokenized_line[t], &(line[i-l]), l);
				tokenized_line[t][l] = '\0';

				t++;
			}

			break;
		} else if (line[i] == ' ') {
			if (l) {
				if (t == CLI_MAX_ACCEPTED_ARGS) {
					t++;
					break;
				}

				tokenized_line[t] = malloc(sizeof(char) * (l+1));
				memcpy(tokenized_line[t], &(line[i-l]), l);
				tokenized_line[t][l] = '\0';

				l = 0;
				t++;
			}
		} else {
			l++;
		}
	}

	if (
		i >= CLI_MAX_LINE_LENGTH ||
		t > CLI_MAX_ACCEPTED_ARGS ||
		l >= CLI_MAX_TOKEN_LENGTH ||
		t == 0
	) goto cli_process_error;

	return tokenized_line;


cli_process_error:
	// print error
	if (i >= CLI_MAX_LINE_LENGTH)
		pr_err("command too long (> %d)\n", CLI_MAX_LINE_LENGTH);

	if (t > CLI_MAX_ACCEPTED_ARGS)
		pr_err("too many arguments (> %d)\n", CLI_MAX_ACCEPTED_ARGS);

	if (l >= CLI_MAX_TOKEN_LENGTH)
		pr_err("argument %d too long (> %d)\n", t, CLI_MAX_TOKEN_LENGTH);

	// clean up
	destroy_tokenized_line(tokenized_line);

	// return
	return NULL;
}


void *format_args(char **tokenized_line, unsigned int arg_count, enum CliArgType *arg_types)
{
	char *new_struct;

	{
		// prepare struct space
		unsigned int struct_size = 0;

		for (unsigned int i = 0; i < arg_count; i++)
			switch (arg_types[i]) {
			case INT:
				struct_size += sizeof(int);
				break;
			case STR:
				struct_size += sizeof(char *);
				break;
			}

		new_struct = malloc(struct_size);
		memset(new_struct, 0, struct_size);
	}

	unsigned int struct_offset = 0;

	for (unsigned int i = 0; i < arg_count; i++)
	{
		if (arg_types[i] == INT) {
			if (!tokenized_line[i+1]) {
				pr_err("missing argument %d of type 'integer'\n", i+1);
				goto abandon_struct;
			}

			int value;
			int result = sscanf(tokenized_line[i+1], "%d", &value);

			if (result != 1) {
				pr_err("argument %d must be of type 'integer'\n", i+1);
				goto abandon_struct;
			}

			*((int*) &(new_struct[struct_offset])) = value;
			struct_offset += sizeof(int);
		}
		else if (arg_types[i] == STR) {
			if (!tokenized_line[i+1]) {
				pr_err("missing argument %d of type 'string'\n", i+1);
				goto abandon_struct;
			}

			*((char**) &(new_struct[struct_offset])) = tokenized_line[i+1];
			struct_offset += sizeof(char *);
		}
	}

	return new_struct;

abandon_struct:
	free(new_struct);
	return NULL;
}


unsigned int cli_poll_process_next(void)
{
	for ( ;; ) {
		fputs("$ ", stdout);

		size_t buf_size = 0;
		char *line = NULL;

		ssize_t result = getline(&line, &buf_size, stdin);
		if (result == -1)
			return 0x1;

		char **tokenized_line = tokenize_line(line, result);
		free(line);

		if (tokenized_line == NULL)
			continue;

		unsigned int i;
		for (i = 0; (i < LEN(cmd)) && strcmp(tokenized_line[0], cmd[i].cmd); i++);
		if (i == LEN(cmd)) {
			pr_err("command '%s' not found\n", tokenized_line[0]);
			destroy_tokenized_line(tokenized_line);
			continue;
		}

		{
			int tll = tokenized_line_len(tokenized_line);

			if ((cmd[i].arg_count + 1) != tll) {
				pr_err("wrong amount of arguments for '%s' (%d required, %d got)\n", tokenized_line[0], cmd[i].arg_count, tll-1);
				destroy_tokenized_line(tokenized_line);
				continue;
			}
		}

		int (*executor)(void *) = cmd[i].process;
		void *data;

		if (cmd[i].arg_count) {
			data = format_args(tokenized_line, cmd[i].arg_count, cmd[i].args);

			if (data == NULL) {
				destroy_tokenized_line(tokenized_line);
				continue;
			}
		} else {
			data = NULL;
		}

		int execution_result_code = executor(data);

		if (data)
			free(data);

		destroy_tokenized_line(tokenized_line);

		if (0x1 == execution_result_code)
			return 0x1;
	}
}