config.c

一个Linux下无线网卡的设置工具

static int wpa_config_parse_cipher(int line, const char *value)
{
	int val = 0, last;
	char *start, *end, *buf;

	buf = strdup(value);
	if (buf == NULL)
		return -1;
	start = buf;

	while (*start != '\0') {
		while (*start == ' ' || *start == '\t')
			start++;
		if (*start == '\0')
			break;
		end = start;
		while (*end != ' ' && *end != '\t' && *end != '\0')
			end++;
		last = *end == '\0';
		*end = '\0';
		if (strcmp(start, "CCMP") == 0)
			val |= WPA_CIPHER_CCMP;
		else if (strcmp(start, "TKIP") == 0)
			val |= WPA_CIPHER_TKIP;
		else if (strcmp(start, "WEP104") == 0)
			val |= WPA_CIPHER_WEP104;
		else if (strcmp(start, "WEP40") == 0)
			val |= WPA_CIPHER_WEP40;
		else if (strcmp(start, "NONE") == 0)
			val |= WPA_CIPHER_NONE;
		else {
			wpa_printf(MSG_ERROR, "Line %d: invalid cipher '%s'.",
				   line, start);
			free(buf);
			return -1;
		}

		if (last)
			break;
		start = end + 1;
	}
	free(buf);

	if (val == 0) {
		wpa_printf(MSG_ERROR, "Line %d: no cipher values configured.",
			   line);
		return -1;
	}
	return val;
}


static char * wpa_config_write_cipher(int cipher)
{
	int first = 1;
	char *buf, *pos, *end;

	pos = buf = malloc(50);
	if (buf == NULL)
		return NULL;
	memset(buf, 0, 50);
	end = buf + 50;

	if (cipher & WPA_CIPHER_CCMP) {
		pos += snprintf(pos, end - pos, "%sCCMP", first ? "" : " ");
		first = 0;
	}

	if (cipher & WPA_CIPHER_TKIP) {
		pos += snprintf(pos, end - pos, "%sTKIP", first ? "" : " ");
		first = 0;
	}

	if (cipher & WPA_CIPHER_WEP104) {
		pos += snprintf(pos, end - pos, "%sWEP104", first ? "" : " ");
		first = 0;
	}

	if (cipher & WPA_CIPHER_WEP40) {
		pos += snprintf(pos, end - pos, "%sWEP40", first ? "" : " ");
		first = 0;
	}

	if (cipher & WPA_CIPHER_NONE) {
		pos += snprintf(pos, end - pos, "%sNONE", first ? "" : " ");
		first = 0;
	}

	return buf;
}


static int wpa_config_parse_pairwise(const struct parse_data *data,
				     struct wpa_ssid *ssid, int line,
				     const char *value)
{
	int val;
	val = wpa_config_parse_cipher(line, value);
	if (val == -1)
		return -1;
	if (val & ~(WPA_CIPHER_CCMP | WPA_CIPHER_TKIP | WPA_CIPHER_NONE)) {
		wpa_printf(MSG_ERROR, "Line %d: not allowed pairwise cipher "
			   "(0x%x).", line, val);
		return -1;
	}

	wpa_printf(MSG_MSGDUMP, "pairwise: 0x%x", val);
	ssid->pairwise_cipher = val;
	return 0;
}


static char * wpa_config_write_pairwise(const struct parse_data *data,
					struct wpa_ssid *ssid)
{
	return wpa_config_write_cipher(ssid->pairwise_cipher);
}


static int wpa_config_parse_group(const struct parse_data *data,
				  struct wpa_ssid *ssid, int line,
				  const char *value)
{
	int val;
	val = wpa_config_parse_cipher(line, value);
	if (val == -1)
		return -1;
	if (val & ~(WPA_CIPHER_CCMP | WPA_CIPHER_TKIP | WPA_CIPHER_WEP104 |
		    WPA_CIPHER_WEP40)) {
		wpa_printf(MSG_ERROR, "Line %d: not allowed group cipher "
			   "(0x%x).", line, val);
		return -1;
	}

	wpa_printf(MSG_MSGDUMP, "group: 0x%x", val);
	ssid->group_cipher = val;
	return 0;
}


static char * wpa_config_write_group(const struct parse_data *data,
				     struct wpa_ssid *ssid)
{
	return wpa_config_write_cipher(ssid->group_cipher);
}


static int wpa_config_parse_auth_alg(const struct parse_data *data,
				     struct wpa_ssid *ssid, int line,
				     const char *value)
{
	int val = 0, last, errors = 0;
	char *start, *end, *buf;

	buf = strdup(value);
	if (buf == NULL)
		return -1;
	start = buf;

	while (*start != '\0') {
		while (*start == ' ' || *start == '\t')
			start++;
		if (*start == '\0')
			break;
		end = start;
		while (*end != ' ' && *end != '\t' && *end != '\0')
			end++;
		last = *end == '\0';
		*end = '\0';
		if (strcmp(start, "OPEN") == 0)
			val |= WPA_AUTH_ALG_OPEN;
		else if (strcmp(start, "SHARED") == 0)
			val |= WPA_AUTH_ALG_SHARED;
		else if (strcmp(start, "LEAP") == 0)
			val |= WPA_AUTH_ALG_LEAP;
		else {
			wpa_printf(MSG_ERROR, "Line %d: invalid auth_alg '%s'",
				   line, start);
			errors++;
		}

		if (last)
			break;
		start = end + 1;
	}
	free(buf);

	if (val == 0) {
		wpa_printf(MSG_ERROR,
			   "Line %d: no auth_alg values configured.", line);
		errors++;
	}

	wpa_printf(MSG_MSGDUMP, "auth_alg: 0x%x", val);
	ssid->auth_alg = val;
	return errors ? -1 : 0;
}


static char * wpa_config_write_auth_alg(const struct parse_data *data,
					struct wpa_ssid *ssid)
{
	int first = 1;
	char *buf, *pos, *end;

	pos = buf = malloc(30);
	if (buf == NULL)
		return NULL;
	memset(buf, 0, 30);
	end = buf + 30;

	if (ssid->auth_alg & WPA_AUTH_ALG_OPEN) {
		pos += snprintf(pos, end - pos, "%sOPEN", first ? "" : " ");
		first = 0;
	}

	if (ssid->auth_alg & WPA_AUTH_ALG_SHARED) {
		pos += snprintf(pos, end - pos, "%sSHARED", first ? "" : " ");
		first = 0;
	}

	if (ssid->auth_alg & WPA_AUTH_ALG_LEAP) {
		pos += snprintf(pos, end - pos, "%sLEAP", first ? "" : " ");
		first = 0;
	}

	return buf;
}


static int wpa_config_parse_eap(const struct parse_data *data,
				struct wpa_ssid *ssid, int line,
				const char *value)
{
	int last, errors = 0;
	char *start, *end, *buf;
	u8 *methods = NULL, *tmp;
	size_t num_methods = 0;

	buf = strdup(value);
	if (buf == NULL)
		return -1;
	start = buf;

	while (*start != '\0') {
		while (*start == ' ' || *start == '\t')
			start++;
		if (*start == '\0')
			break;
		end = start;
		while (*end != ' ' && *end != '\t' && *end != '\0')
			end++;
		last = *end == '\0';
		*end = '\0';
		tmp = methods;
		methods = realloc(methods, num_methods + 1);
		if (methods == NULL) {
			free(tmp);
			free(buf);
			return -1;
		}
		methods[num_methods] = eap_get_type(start);
		if (methods[num_methods] == EAP_TYPE_NONE) {
			wpa_printf(MSG_ERROR, "Line %d: unknown EAP method "
				   "'%s'", line, start);
			wpa_printf(MSG_ERROR, "You may need to add support for"
				   " this EAP method during wpa_supplicant\n"
				   "build time configuration.\n"
				   "See README for more information.");
			errors++;
		} else if (methods[num_methods] == EAP_TYPE_LEAP)
			ssid->leap++;
		else
			ssid->non_leap++;
		num_methods++;
		if (last)
			break;
		start = end + 1;
	}
	free(buf);

	tmp = methods;
	methods = realloc(methods, num_methods + 1);
	if (methods == NULL) {
		free(tmp);
		return -1;
	}
	methods[num_methods] = EAP_TYPE_NONE;
	num_methods++;

	wpa_hexdump(MSG_MSGDUMP, "eap methods", methods, num_methods);
	ssid->eap_methods = methods;
	return errors ? -1 : 0;
}


static char * wpa_config_write_eap(const struct parse_data *data,
				   struct wpa_ssid *ssid)
{
	int first = 1;
	char *buf, *pos, *end;
	const u8 *eap_methods = ssid->eap_methods;
	const char *name;

	if (eap_methods == NULL)
		return NULL;

	pos = buf = malloc(100);
	if (buf == NULL)
		return NULL;
	memset(buf, 0, 100);
	end = buf + 100;

	while (*eap_methods != EAP_TYPE_NONE) {
		name = eap_get_name(*eap_methods);
		if (name)
			pos += snprintf(pos, end - pos, "%s%s",
					first ? "" : " ", name);
		first = 0;
		eap_methods++;
	}

	return buf;
}


static int wpa_config_parse_wep_key(u8 *key, size_t *len, int line,
				    const char *value, int idx)
{
	char *buf, title[20];

	buf = wpa_config_parse_string(value, len);
	if (buf == NULL) {
		wpa_printf(MSG_ERROR, "Line %d: Invalid WEP key %d '%s'.",
			   line, idx, value);
		return -1;
	}
	if (*len > MAX_WEP_KEY_LEN) {
		wpa_printf(MSG_ERROR, "Line %d: Too long WEP key %d '%s'.",
			   line, idx, value);
		free(buf);
		return -1;
	}
	memcpy(key, buf, *len);
	free(buf);
	snprintf(title, sizeof(title), "wep_key%d", idx);
	wpa_hexdump_key(MSG_MSGDUMP, title, key, *len);
	return 0;
}


static int wpa_config_parse_wep_key0(const struct parse_data *data,
				     struct wpa_ssid *ssid, int line,
				     const char *value)
{
	return wpa_config_parse_wep_key(ssid->wep_key[0],
					&ssid->wep_key_len[0], line,
					value, 0);
}


static int wpa_config_parse_wep_key1(const struct parse_data *data,
				     struct wpa_ssid *ssid, int line,
				     const char *value)
{
	return wpa_config_parse_wep_key(ssid->wep_key[1],
					&ssid->wep_key_len[1], line,
					value, 1);
}


static int wpa_config_parse_wep_key2(const struct parse_data *data,
				     struct wpa_ssid *ssid, int line,
				     const char *value)
{
	return wpa_config_parse_wep_key(ssid->wep_key[2],
					&ssid->wep_key_len[2], line,
					value, 2);
}


static int wpa_config_parse_wep_key3(const struct parse_data *data,
				     struct wpa_ssid *ssid, int line,
				     const char *value)
{
	return wpa_config_parse_wep_key(ssid->wep_key[3],
					&ssid->wep_key_len[3], line,
					value, 3);
}


static char * wpa_config_write_wep_key(struct wpa_ssid *ssid, int idx)
{
	if (ssid->wep_key_len[idx] == 0)
		return NULL;
	return wpa_config_write_string(ssid->wep_key[idx],
				       ssid->wep_key_len[idx]);
}


static char * wpa_config_write_wep_key0(const struct parse_data *data,
					struct wpa_ssid *ssid)
{
	return wpa_config_write_wep_key(ssid, 0);
}


static char * wpa_config_write_wep_key1(const struct parse_data *data,
					struct wpa_ssid *ssid)
{
	return wpa_config_write_wep_key(ssid, 1);
}


static char * wpa_config_write_wep_key2(const struct parse_data *data,
					struct wpa_ssid *ssid)
{
	return wpa_config_write_wep_key(ssid, 2);
}


static char * wpa_config_write_wep_key3(const struct parse_data *data,
					struct wpa_ssid *ssid)
{
	return wpa_config_write_wep_key(ssid, 3);
}


/* Helper macros for network block parser */

/* OFFSET: Get offset of a variable within the wpa_ssid structure */
#define OFFSET(v) ((void *) &((struct wpa_ssid *) 0)->v)

/* STR: Define a string variable for an ASCII string; f = field name */
#define STR(f) .name = #f, .parser = wpa_config_parse_str, \
	.writer = wpa_config_write_str, .param1 = OFFSET(f)

/* STR_LEN: Define a string variable with a separate variable for storing the
 * data length. Unlike STR(), this can be used to store arbitrary binary data
 * (i.e., even nul termination character). */
#define STR_LEN(f) STR(f), .param2 = OFFSET(f ## _len)

/* STR_RANGE: Like STR_LEN(), but with minimum and maximum allowed length
 * explicitly specified. */
#define STR_RANGE(f, min, max) STR_LEN(f), .param3 = (void *) (min), \
	.param4 = (void *) (max)


/* INT: Define an integer variable */
#define INT(f) .name = #f, .parser = wpa_config_parse_int, \
	.writer = wpa_config_write_int, \
	.param1 = OFFSET(f), .param2 = (void *) 0

/* INT: Define an integer variable with allowed value range */
#define INT_RANGE(f, min, max) INT(f), .param3 = (void *) (min), \
	.param4 = (void *) (max)

/* FUNC: Define a configuration variable that uses a custom function for
 * parsing and writing the value. */
#define FUNC(f) .name = #f, .parser = wpa_config_parse_ ## f, \
		.writer = wpa_config_write_ ## f

/*
 * Table of network configuration variables. This table is used to parse each
 * network configuration variable, e.g., each line in wpa_supplicant.conf file
 * that is inside a network block.
 *
 * This table is generated using the helper macros defined above and with
 * generous help from the C pre-processor. The field name is stored as a string
 * into .name and for STR and INT types, the offset of the target buffer within
 * struct wpa_ssid is stored in .param1. .param2 (if not NULL) is similar
 * offset to the field containing the length of the configuration variable.
 * .param3 and .param4 can be used to mark the allowed range (length for STR
 * and value for INT).
 *
 * For each configuration line in wpa_supplicant.conf, the parser goes through
 * this table and select the entry that matches with the field name. The parser
 * function (.parser) is then called to parse the actual value of the field.
 *
 * This kind of mechanism makes it easy to add new configuration parameters,
 * since only one line needs to be added into this table and into the
 * struct wpa_ssid definition if the new variable is either a string or
 * integer. More complex types will need to use their own parser and writer
 * functions.
 */
static const struct parse_data ssid_fields[] = {
	{ STR_RANGE(ssid, 0, MAX_SSID_LEN) },
	{ INT_RANGE(scan_ssid, 0, 1) },
	{ FUNC(bssid) },
	{ FUNC(psk), .key_data = 1 },
	{ FUNC(proto) },
	{ FUNC(key_mgmt) },
	{ FUNC(pairwise) },
	{ FUNC(group) },
	{ FUNC(auth_alg) },
	{ FUNC(eap) },
	{ STR_LEN(identity) },
	{ STR_LEN(anonymous_identity) },
	{ STR_RANGE(eappsk, EAP_PSK_LEN, EAP_PSK_LEN), .key_data = 1 },
	{ STR_LEN(nai) },
	{ STR_LEN(password), .key_data = 1 },
	{ STR(ca_cert) },
	{ STR(ca_path) },
	{ STR(client_cert) },
	{ STR(private_key) },
	{ STR(private_key_passwd), .key_data = 1 },
	{ STR(dh_file) },
	{ STR(subject_match) },
	{ STR(altsubject_match) },
	{ STR(ca_cert2) },
	{ STR(ca_path2) },
	{ STR(client_cert2) },
	{ STR(private_key2) },
	{ STR(private_key2_passwd), .key_data = 1 },
	{ STR(dh_file2) },
	{ STR(subject_match2) },
	{ STR(altsubject_match2) },
	{ STR(phase1) },
	{ STR(phase2) },
	{ STR(pcsc) },