init_parse.c

ALSA驱动的一些调试测试工具

	}
	if (strncasecmp(attr, "step", 3) == 0) {
		if (check_id_changed(space, 1))
			return NULL;
		type = snd_ctl_elem_info_get_type(space->ctl_info);
		if (type == SND_CTL_ELEM_TYPE_INTEGER64)
			val = snd_ctl_elem_info_get_step64(space->ctl_info);
		else if (type == SND_CTL_ELEM_TYPE_INTEGER)
			val = snd_ctl_elem_info_get_step(space->ctl_info);
		else
			goto empty;
		goto value;
	}
	if (strncasecmp(attr, "items", 5) == 0) {
		if (check_id_changed(space, 1))
			return NULL;
		if (snd_ctl_elem_info_get_type(space->ctl_info) == SND_CTL_ELEM_TYPE_ENUMERATED)
			val = snd_ctl_elem_info_get_items(space->ctl_info);
		else {
		  empty:
			res[0] = '\0';
			return res;
		}
		goto value;
	}
	if (strncasecmp(attr, "value", 5) == 0) {
		if (check_id_changed(space, 3))
			return NULL;
		return get_ctl_value(space);
	}
	if (strncasecmp(attr, "dBmin", 5) == 0) {
		long min, max;
		if (check_id_changed(space, 1))
			return NULL;
		if (snd_ctl_get_dB_range(snd_hctl_ctl(space->ctl_handle), space->ctl_id, &min, &max) < 0)
			goto empty;
		val = min;
dbvalue:
		sprintf(res, "%li.%02idB", (long)(val / 100), (int)abs(val % 100));
		return res;
	}
	if (strncasecmp(attr, "dBmax", 5) == 0) {
		long min, max;
		if (check_id_changed(space, 1))
			return NULL;
		if (snd_ctl_get_dB_range(snd_hctl_ctl(space->ctl_handle), space->ctl_id, &min, &max) < 0)
			goto empty;
		val = max;
		goto dbvalue;
	}
	if (strncasecmp(attr, "enums", 5) == 0) {
		unsigned int idx, items;
		snd_hctl_elem_t *elem;
		if (check_id_changed(space, 1))
			return NULL;
		if (snd_ctl_elem_info_get_type(space->ctl_info) != SND_CTL_ELEM_TYPE_ENUMERATED)
			goto empty;
		items = snd_ctl_elem_info_get_items(space->ctl_info);
		strcpy(res, "|");
		for (idx = 0; idx < items; idx++) {
			snd_ctl_elem_info_set_item(space->ctl_info, idx);
			elem = snd_hctl_find_elem(space->ctl_handle, space->ctl_id);
			if (elem == NULL)
				break;
			if (snd_hctl_elem_info(elem, space->ctl_info) < 0)
				break;
			strlcat(res, snd_ctl_elem_info_get_item_name(space->ctl_info), sizeof(res));
			strlcat(res, "|", sizeof(res));
		}
		return res;
	}
	Perror(space, "unknown ctl{} attribute '%s'", attr);
	return NULL;
  value:
  	sprintf(res, "%lli", val);
  	return res;
}

static int elemid_set(struct space *space, const char *attr, const char *value)
{
	unsigned int val;
	void (*fcn)(snd_ctl_elem_id_t *, unsigned int);
	snd_ctl_elem_iface_t iface;
	int err;

	if (strncasecmp(attr, "numid", 5) == 0) {
		fcn = snd_ctl_elem_id_set_numid;
	    	goto value;
	}
	if (strncasecmp(attr, "iface", 5) == 0 ||
	    strncasecmp(attr, "interface", 9) == 0 ||
	    strncasecmp(attr, "reset", 5) == 0 ||
	    strncasecmp(attr, "search", 6) == 0) {
	    	if (strlen(value) == 0 && strncasecmp(attr, "search", 6) == 0) {
	    		iface = 0;
	    		goto search;
		}
	    	for (iface = 0; iface <= SND_CTL_ELEM_IFACE_LAST; iface++) {
	    		if (strcasecmp(value, snd_ctl_elem_iface_name(iface)) == 0) {
			    	if (strncasecmp(attr, "reset", 5) == 0)
			    		snd_ctl_elem_id_clear(space->ctl_id);
			    	if (strncasecmp(attr, "search", 5) == 0) {
			    	  search:
			    		snd_ctl_elem_id_clear(space->ctl_id);
			    		/* -1 means all */
			    		snd_ctl_elem_id_set_interface(space->ctl_id, -1);
			    		snd_ctl_elem_id_set_device(space->ctl_id, -1);
			    		snd_ctl_elem_id_set_subdevice(space->ctl_id, -1);
			    		snd_ctl_elem_id_set_name(space->ctl_id, "*");
			    		snd_ctl_elem_id_set_index(space->ctl_id, -1);
			    		if (strlen(value) == 0)
			    			return 0;
				}
				snd_ctl_elem_id_set_interface(space->ctl_id, iface);
				space->ctl_id_changed = ~0;
			    	return 0;
			}
		}
		Perror(space, "unknown control interface name '%s'", value);
		return -EINVAL;
	}
	if (strncasecmp(attr, "device", 6) == 0) {
		fcn = snd_ctl_elem_id_set_device;
	    	goto value;
	}
	if (strncasecmp(attr, "subdev", 6) == 0) {
		fcn = snd_ctl_elem_id_set_subdevice;
	    	goto value;
	}
	if (strncasecmp(attr, "name", 4) == 0) {
		snd_ctl_elem_id_set_name(space->ctl_id, value);
	  	space->ctl_id_changed = ~0;
		return 0;
	}
	if (strncasecmp(attr, "index", 5) == 0) {
		fcn = snd_ctl_elem_id_set_index;
	    	goto value;
	}
	if (strncasecmp(attr, "values", 6) == 0 ||
	    strncasecmp(attr, "value", 5) == 0) {
		err = check_id_changed(space, 1);
		if (err < 0) {
			Perror(space, "control element not found");
			return err;
		}
		err = set_ctl_value(space, value, strncasecmp(attr, "values", 6) == 0);
		if (err < 0) {
			space->ctl_id_changed |= 2;
		} else {
			space->ctl_id_changed &= ~2;
			snd_ctl_elem_value_set_id(space->ctl_value, space->ctl_id);
			err = snd_ctl_elem_write(snd_hctl_ctl(space->ctl_handle), space->ctl_value);
			if (err < 0) {
				Perror(space, "value write error: %s", snd_strerror(err));
				return err;
			}
		}
	    	return err;
	}
	Perror(space, "unknown CTL{} attribute '%s'", attr);
	return -EINVAL;
  value:
  	val = (unsigned int)strtol(value, NULL, 0);
  	fcn(space->ctl_id, val);
  	space->ctl_id_changed = ~0;
  	return 0;
}

static int get_key(char **line, char **key, enum key_op *op, char **value)
{
	char *linepos;
	char *temp;

	linepos = *line;
	if (linepos == NULL && linepos[0] == '\0')
		return -EINVAL;

	/* skip whitespace */
	while (isspace(linepos[0]) || linepos[0] == ',')
		linepos++;

	/* get the key */
	if (linepos[0] == '\0')
		return -EINVAL;
	*key = linepos;

	while (1) {
		linepos++;
		if (linepos[0] == '\0')
			return -1;
		if (isspace(linepos[0]))
			break;
		if (linepos[0] == '=')
			break;
		if (linepos[0] == '+')
			break;
		if (linepos[0] == '!')
			break;
		if (linepos[0] == ':')
			break;
	}

	/* remember end of key */
	temp = linepos;

	/* skip whitespace after key */
	while (isspace(linepos[0]))
		linepos++;
	if (linepos[0] == '\0')
		return -EINVAL;

	/* get operation type */
	if (linepos[0] == '=' && linepos[1] == '=') {
		*op = KEY_OP_MATCH;
		linepos += 2;
		dbg("operator=match");
	} else if (linepos[0] == '!' && linepos[1] == '=') {
		*op = KEY_OP_NOMATCH;
		linepos += 2;
		dbg("operator=nomatch");
	} else if (linepos[0] == '+' && linepos[1] == '=') {
		*op = KEY_OP_ADD;
		linepos += 2;
		dbg("operator=add");
	} else if (linepos[0] == '=') {
		*op = KEY_OP_ASSIGN;
		linepos++;
		dbg("operator=assign");
	} else if (linepos[0] == ':' && linepos[1] == '=') {
		*op = KEY_OP_ASSIGN_FINAL;
		linepos += 2;
		dbg("operator=assign_final");
	} else
		return -EINVAL;

	/* terminate key */
	temp[0] = '\0';
	dbg("key='%s'", *key);

	/* skip whitespace after operator */
	while (isspace(linepos[0]))
		linepos++;
	if (linepos[0] == '\0')
		return -EINVAL;

	/* get the value*/
	if (linepos[0] != '"')
		return -EINVAL;
	linepos++;
	*value = linepos;

	while (1) {
		temp = strchr(linepos, '"');
		if (temp && temp[-1] == '\\') {
			linepos = temp + 1;
			continue;
		}
		break;
	}
	if (!temp)
		return -EINVAL;
	temp[0] = '\0';
	temp++;
	dbg("value='%s'", *value);

	/* move line to next key */
	*line = temp;

	return 0;
}

/* extract possible KEY{attr} */
static char *get_key_attribute(struct space *space, char *str, char *res, size_t ressize)
{
	char *pos;
	char *attr;

	attr = strchr(str, '{');
	if (attr != NULL) {
		attr++;
		pos = strchr(attr, '}');
		if (pos == NULL) {
			Perror(space, "missing closing brace for format");
			return NULL;
		}
		pos[0] = '\0';
		strlcpy(res, attr, ressize);
		pos[0] = '}';
		dbg("attribute='%s'", res);
		return res;
	}

	return NULL;
}

/* extract possible {attr} and move str behind it */
static char *get_format_attribute(struct space *space, char **str)
{
	char *pos;
	char *attr = NULL;

	if (*str[0] == '{') {
		pos = strchr(*str, '}');
		if (pos == NULL) {
			Perror(space, "missing closing brace for format");
			return NULL;
		}
		pos[0] = '\0';
		attr = *str+1;
		*str = pos+1;
		dbg("attribute='%s', str='%s'", attr, *str);
	}
	return attr;
}

/* extract possible format length and move str behind it*/
static int get_format_len(struct space *space, char **str)
{
	int num;
	char *tail;

	if (isdigit(*str[0])) {
		num = (int) strtoul(*str, &tail, 10);
		if (num > 0) {
			*str = tail;
			dbg("format length=%i", num);
			return num;
		} else {
			Perror(space, "format parsing error '%s'", *str);
		}
	}
	return -1;
}

static void apply_format(struct space *space, char *string, size_t maxsize)
{
	char temp[PATH_SIZE];
	char temp2[PATH_SIZE];
	char *head, *tail, *pos, *cpos, *attr, *rest;
	struct pair *pair;
	int len;
	int i;
	int count;
	enum subst_type {
		SUBST_UNKNOWN,
		SUBST_CARDINFO,
		SUBST_CTL,
		SUBST_RESULT,
		SUBST_ATTR,
		SUBST_SYSFSROOT,
		SUBST_ENV,
	};
	static const struct subst_map {
		char *name;
		char fmt;
		enum subst_type type;
	} map[] = {
		{ .name = "cardinfo",	.fmt = 'i',	.type = SUBST_CARDINFO },
		{ .name = "ctl",	.fmt = 'C',	.type = SUBST_CTL },
		{ .name = "result",	.fmt = 'c',	.type = SUBST_RESULT },
		{ .name = "attr",	.fmt = 's',	.type = SUBST_ATTR },
		{ .name = "sysfsroot",	.fmt = 'r',	.type = SUBST_SYSFSROOT },
		{ .name = "env",	.fmt = 'E',	.type = SUBST_ENV },
		{ NULL, '\0', 0 }
	};
	enum subst_type type;
	const struct subst_map *subst;

	head = string;
	while (1) {
		len = -1;
		while (head[0] != '\0') {
			if (head[0] == '$') {
				/* substitute named variable */
				if (head[1] == '\0')
					break;
				if (head[1] == '$') {
					strlcpy(temp, head+2, sizeof(temp));
					strlcpy(head+1, temp, maxsize);
					head++;
					continue;
				}
				head[0] = '\0';
				for (subst = map; subst->name; subst++) {
					if (strncasecmp(&head[1], subst->name, strlen(subst->name)) == 0) {
						type = subst->type;
						tail = head + strlen(subst->name)+1;
						dbg("will substitute format name '%s'", subst->name);
						goto found;
					}
				}
			} else if (head[0] == '%') {
				/* substitute format char */
				if (head[1] == '\0')
					break;
				if (head[1] == '%') {
					strlcpy(temp, head+2, sizeof(temp));
					strlcpy(head+1, temp, maxsize);
					head++;
					continue;
				}
				head[0] = '\0';
				tail = head+1;
				len = get_format_len(space, &tail);
				for (subst = map; subst->name; subst++) {
					if (tail[0] == subst->fmt) {
						type = subst->type;
						tail++;
						dbg("will substitute format char '%c'", subst->fmt);
						goto found;
					}
				}
			}
			head++;
		}
		break;
found:
		attr = get_format_attribute(space, &tail);
		strlcpy(temp, tail, sizeof(temp));
		dbg("format=%i, string='%s', tail='%s'", type ,string, tail);

		switch (type) {
		case SUBST_CARDINFO:
			if (attr == NULL)
				Perror(space, "missing identification parametr for cardinfo");
			else {
				const char *value = cardinfo_get(space, attr);
				if (value == NULL)
					break;
				strlcat(string, value, maxsize);
				dbg("substitute cardinfo{%s} '%s'", attr, value);
			}
			break;
		case SUBST_CTL:
			if (attr == NULL)
				Perror(space, "missing identification parametr for ctl");
			else {
				const char *value = elemid_get(space, attr);
				if (value == NULL)
					break;
				strlcat(string, value, maxsize);
				dbg("substitute ctl{%s} '%s'", attr, value);
			}
			break;
		case SUBST_RESULT:
			if (space->program_result == NULL)
				break;
			/* get part part of the result string */
			i = 0;
			if (attr != NULL)
				i = strtoul(attr, &rest, 10);
			if (i > 0) {
				dbg("request part #%d of result string", i);
				cpos = space->program_result;
				while (--i) {
					while (cpos[0] != '\0' && !isspace(cpos[0]))
						cpos++;
					while (isspace(cpos[0]))
						cpos++;
				}
				if (i > 0) {
					Perror(space, "requested part of result string not found");
					break;
				}
				strlcpy(temp2, cpos, sizeof(temp2));
				/* %{2+}c copies the whole string from the second part on */
				if (rest[0] != '+') {
					cpos = strchr(temp2, ' ');
					if (cpos)
						cpos[0] = '\0';
				}
				strlcat(string, temp2, maxsize);
				dbg("substitute part of result string '%s'", temp2);
			} else {
				strlcat(string, space->program_result, maxsize);
				dbg("substitute result string '%s'", space->program_result);
			}
			break;
		case SUBST_ATTR:
			if (attr == NULL)
				Perror(space, "missing file parameter for attr");
			else {
				const char *value = NULL;
				size_t size;

				pair = value_find(space, "sysfs_device");
				if (pair == NULL)
					break;
				value = sysfs_attr_get_value(pair->value, attr);

				if (value == NULL)
					break;

				/* strip trailing whitespace and replace untrusted characters of sysfs value */
				size = strlcpy(temp2, value, sizeof(temp2));
				if (size >= sizeof(temp2))
					size = sizeof(temp2)-1;
				while (size > 0 && isspace(temp2[size-1]))
					temp2[--size] = '\0';
				count = replace_untrusted_chars(temp2);
				if (count > 0)
					Perror(space, "%i untrusted character(s) replaced" , count);
				strlcat(string, temp2, maxsize);
				dbg("substitute sysfs value '%s'", temp2);
			}
			break;
		case SUBST_SYSFSROOT:
			strlcat(string, sysfs_path, maxsize);
			dbg("substitute sysfs_path '%s'", sysfs_path);
			break;
		case SUBST_ENV:
			if (attr == NULL) {
				dbg("missing attribute");
				break;
			}
			pos = getenv(attr);
			if (pos == NULL) {
				dbg("env '%s' not available", attr);
				break;
			}
			dbg("substitute env '%s=%s'", attr, pos);
			strlcat(string, pos, maxsize);
			break;
		default:
			Perror(space, "unknown substitution type=%i", type);
			break;
		}
		/* possibly truncate to format-char specified length */
		if (len != -1) {
			head[len] = '\0';
			dbg("truncate to %i chars, subtitution string becomes '%s'", len, head);
		}
		strlcat(string, temp, maxsize);
	}
	/* unescape strings */
	head = tail = string;
	while (*head != '\0') {
		if (*head == '\\') {
			head++;
			if (*head == '\0')
				break;
			switch (*head) {
			case 'a': *tail++ = '\a'; break;
			case 'b': *tail++ = '\b'; break;
			case 'n': *tail++ = '\n'; break;
			case 'r': *tail++ = '\r'; break;
			case 't': *tail++ = '\t'; break;
			case 'v': *tail++ = '\v'; break;
			case '\\': *tail++ = '\\'; break;
			default: *tail++ = *head; break;
			}
			head++;
			continue;
		}
		if (*head)
			*tail++ = *head++;
	}
	*tail = 0;
}

static int do_match(const char *key, enum key_op op,
		    const char *key_value, const char *value)
{
	int match;

	if (value == NULL)
		return 0;
	dbg("match %s '%s' <-> '%s'", key, key_value, value);
	match = fnmatch(key_value, value, 0) == 0;
	if (match && op == KEY_OP_MATCH) {
		dbg("%s is true (matching value)", key);
		return 1;
	}
	if (!match && op == KEY_OP_NOMATCH) {
		dbg("%s is true (non-matching value)", key);
		return 1;
	}
	dbg("%s is false", key);
	return 0;
}