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-rw-r--r--config.c225
1 files changed, 1 insertions, 224 deletions
diff --git a/config.c b/config.c
index db0abc8..554db0e 100644
--- a/config.c
+++ b/config.c
@@ -35,66 +35,6 @@
struct clat_config Global_Clatd_Config;
-/* function: config_item_str
- * locates the config item and returns the pointer to a string, or NULL on failure. Caller frees
- * pointer
- * root - parsed configuration
- * item_name - name of config item to locate
- * defaultvar - value to use if config item isn't present
- */
-char *config_item_str(cnode *root, const char *item_name, const char *defaultvar) {
- const char *tmp;
-
- if (!(tmp = config_str(root, item_name, defaultvar))) {
- logmsg(ANDROID_LOG_FATAL, "%s config item needed", item_name);
- return NULL;
- }
- return strdup(tmp);
-}
-
-/* function: config_item_int16_t
- * locates the config item, parses the integer, and returns the pointer ret_val_ptr, or NULL on
- * failure
- * root - parsed configuration
- * item_name - name of config item to locate
- * defaultvar - value to use if config item isn't present
- * ret_val_ptr - pointer for return value storage
- */
-int16_t *config_item_int16_t(cnode *root, const char *item_name, const char *defaultvar,
- int16_t *ret_val_ptr) {
- const char *tmp;
- char *endptr;
- long int conf_int;
-
- if (!(tmp = config_str(root, item_name, defaultvar))) {
- logmsg(ANDROID_LOG_FATAL, "%s config item needed", item_name);
- return NULL;
- }
-
- errno = 0;
- conf_int = strtol(tmp, &endptr, 10);
- if (errno > 0) {
- logmsg(ANDROID_LOG_FATAL, "%s config item is not numeric: %s (error=%s)", item_name, tmp,
- strerror(errno));
- return NULL;
- }
- if (endptr == tmp || *tmp == '\0') {
- logmsg(ANDROID_LOG_FATAL, "%s config item is not numeric: %s", item_name, tmp);
- return NULL;
- }
- if (*endptr != '\0') {
- logmsg(ANDROID_LOG_FATAL, "%s config item contains non-numeric characters: %s", item_name,
- endptr);
- return NULL;
- }
- if (conf_int > INT16_MAX || conf_int < INT16_MIN) {
- logmsg(ANDROID_LOG_FATAL, "%s config item is too big/small: %d", item_name, conf_int);
- return NULL;
- }
- *ret_val_ptr = conf_int;
- return ret_val_ptr;
-}
-
/* function: config_item_ip
* locates the config item, parses the ipv4 address, and returns the pointer ret_val_ptr, or NULL on
* failure
@@ -122,33 +62,6 @@ struct in_addr *config_item_ip(cnode *root, const char *item_name, const char *d
return ret_val_ptr;
}
-/* function: config_item_ip6
- * locates the config item, parses the ipv6 address, and returns the pointer ret_val_ptr, or NULL on
- * failure
- * root - parsed configuration
- * item_name - name of config item to locate
- * defaultvar - value to use if config item isn't present
- * ret_val_ptr - pointer for return value storage
- */
-struct in6_addr *config_item_ip6(cnode *root, const char *item_name, const char *defaultvar,
- struct in6_addr *ret_val_ptr) {
- const char *tmp;
- int status;
-
- if (!(tmp = config_str(root, item_name, defaultvar))) {
- logmsg(ANDROID_LOG_FATAL, "%s config item needed", item_name);
- return NULL;
- }
-
- status = inet_pton(AF_INET6, tmp, ret_val_ptr);
- if (status <= 0) {
- logmsg(ANDROID_LOG_FATAL, "invalid IPv6 address specified for %s: %s", item_name, tmp);
- return NULL;
- }
-
- return ret_val_ptr;
-}
-
/* function: ipv6_prefix_equal
* compares the prefixes two ipv6 addresses. assumes the prefix lengths are both /64.
* a1 - first address
@@ -157,107 +70,6 @@ struct in6_addr *config_item_ip6(cnode *root, const char *item_name, const char
*/
int ipv6_prefix_equal(struct in6_addr *a1, struct in6_addr *a2) { return !memcmp(a1, a2, 8); }
-/* function: gen_random_iid
- * picks a random interface ID that is checksum neutral with the IPv4 address and the NAT64 prefix
- * myaddr - IPv6 address to write to
- * ipv4_local_subnet - clat IPv4 address
- * plat_subnet - NAT64 prefix
- */
-void gen_random_iid(struct in6_addr *myaddr, struct in_addr *ipv4_local_subnet,
- struct in6_addr *plat_subnet) {
- // Fill last 8 bytes of IPv6 address with random bits.
- arc4random_buf(&myaddr->s6_addr[8], 8);
-
- // Make the IID checksum-neutral. That is, make it so that:
- // checksum(Local IPv4 | Remote IPv4) = checksum(Local IPv6 | Remote IPv6)
- // in other words (because remote IPv6 = NAT64 prefix | Remote IPv4):
- // checksum(Local IPv4) = checksum(Local IPv6 | NAT64 prefix)
- // Do this by adjusting the two bytes in the middle of the IID.
-
- uint16_t middlebytes = (myaddr->s6_addr[11] << 8) + myaddr->s6_addr[12];
-
- uint32_t c1 = ip_checksum_add(0, ipv4_local_subnet, sizeof(*ipv4_local_subnet));
- uint32_t c2 = ip_checksum_add(0, plat_subnet, sizeof(*plat_subnet)) +
- ip_checksum_add(0, myaddr, sizeof(*myaddr));
-
- uint16_t delta = ip_checksum_adjust(middlebytes, c1, c2);
- myaddr->s6_addr[11] = delta >> 8;
- myaddr->s6_addr[12] = delta & 0xff;
-}
-
-// Factored out to a separate function for testability.
-int connect_is_ipv4_address_free(in_addr_t addr) {
- int s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
- if (s == -1) {
- return 0;
- }
-
- // Attempt to connect to the address. If the connection succeeds and getsockname returns the same
- // the address then the address is already assigned to the system and we can't use it.
- struct sockaddr_in sin = { .sin_family = AF_INET, .sin_addr = { addr }, .sin_port = htons(53) };
- socklen_t len = sizeof(sin);
- int inuse = connect(s, (struct sockaddr *)&sin, sizeof(sin)) == 0 &&
- getsockname(s, (struct sockaddr *)&sin, &len) == 0 && (size_t)len >= sizeof(sin) &&
- sin.sin_addr.s_addr == addr;
-
- close(s);
- return !inuse;
-}
-
-addr_free_func config_is_ipv4_address_free = connect_is_ipv4_address_free;
-
-/* function: config_select_ipv4_address
- * picks a free IPv4 address, starting from ip and trying all addresses in the prefix in order
- * ip - the IP address from the configuration file
- * prefixlen - the length of the prefix from which addresses may be selected.
- * returns: the IPv4 address, or INADDR_NONE if no addresses were available
- */
-in_addr_t config_select_ipv4_address(const struct in_addr *ip, int16_t prefixlen) {
- in_addr_t chosen = INADDR_NONE;
-
- // Don't accept prefixes that are too large because we scan addresses one by one.
- if (prefixlen < 16 || prefixlen > 32) {
- return chosen;
- }
-
- // All these are in host byte order.
- in_addr_t mask = 0xffffffff >> (32 - prefixlen) << (32 - prefixlen);
- in_addr_t ipv4 = ntohl(ip->s_addr);
- in_addr_t first_ipv4 = ipv4;
- in_addr_t prefix = ipv4 & mask;
-
- // Pick the first IPv4 address in the pool, wrapping around if necessary.
- // So, for example, 192.0.0.4 -> 192.0.0.5 -> 192.0.0.6 -> 192.0.0.7 -> 192.0.0.0.
- do {
- if (config_is_ipv4_address_free(htonl(ipv4))) {
- chosen = htonl(ipv4);
- break;
- }
- ipv4 = prefix | ((ipv4 + 1) & ~mask);
- } while (ipv4 != first_ipv4);
-
- return chosen;
-}
-
-/* function: config_generate_local_ipv6_subnet
- * generates the local ipv6 subnet when given the interface ip requires config.ipv6_host_id
- * interface_ip - in: interface ip, out: local ipv6 host address
- */
-void config_generate_local_ipv6_subnet(struct in6_addr *interface_ip) {
- int i;
-
- if (Global_Clatd_Config.use_dynamic_iid) {
- /* Generate a random interface ID. */
- gen_random_iid(interface_ip, &Global_Clatd_Config.ipv4_local_subnet,
- &Global_Clatd_Config.plat_subnet);
- } else {
- /* Use the specified interface ID. */
- for (i = 2; i < 4; i++) {
- interface_ip->s6_addr32[i] = Global_Clatd_Config.ipv6_host_id.s6_addr32[i];
- }
- }
-}
-
/* function: read_config
* reads the config file and parses it into the global variable Global_Clatd_Config. returns 0 on
* failure, 1 on success
@@ -266,7 +78,6 @@ void config_generate_local_ipv6_subnet(struct in6_addr *interface_ip) {
*/
int read_config(const char *file, const char *uplink_interface) {
cnode *root = config_node("", "");
- unsigned flags;
if (!root) {
logmsg(ANDROID_LOG_FATAL, "out of memory");
@@ -288,22 +99,7 @@ int read_config(const char *file, const char *uplink_interface) {
&Global_Clatd_Config.ipv4_local_subnet))
goto failed;
- if (!config_item_int16_t(root, "ipv4_local_prefixlen", DEFAULT_IPV4_LOCAL_PREFIXLEN,
- &Global_Clatd_Config.ipv4_local_prefixlen))
- goto failed;
-
- if (!config_item_ip6(root, "ipv6_host_id", "::", &Global_Clatd_Config.ipv6_host_id)) goto failed;
-
- /* In order to prevent multiple devices attempting to use the same clat address, never use a
- statically-configured interface ID on a broadcast interface such as wifi. */
- if (!IN6_IS_ADDR_UNSPECIFIED(&Global_Clatd_Config.ipv6_host_id)) {
- ifc_init();
- ifc_get_info(Global_Clatd_Config.default_pdp_interface, NULL, NULL, &flags);
- ifc_close();
- Global_Clatd_Config.use_dynamic_iid = (flags & IFF_BROADCAST) != 0;
- } else {
- Global_Clatd_Config.use_dynamic_iid = 1;
- }
+ Global_Clatd_Config.ipv4_local_prefixlen = 29;
return 1;
@@ -311,22 +107,3 @@ failed:
free(root);
return 0;
}
-
-/* function; dump_config
- * prints the current config
- */
-void dump_config() {
- char charbuffer[INET6_ADDRSTRLEN];
-
- logmsg(
- ANDROID_LOG_DEBUG, "ipv6_local_subnet = %s",
- inet_ntop(AF_INET6, &Global_Clatd_Config.ipv6_local_subnet, charbuffer, sizeof(charbuffer)));
- logmsg(
- ANDROID_LOG_DEBUG, "ipv4_local_subnet = %s",
- inet_ntop(AF_INET, &Global_Clatd_Config.ipv4_local_subnet, charbuffer, sizeof(charbuffer)));
- logmsg(ANDROID_LOG_DEBUG, "ipv4_local_prefixlen = %d", Global_Clatd_Config.ipv4_local_prefixlen);
- logmsg(ANDROID_LOG_DEBUG, "plat_subnet = %s",
- inet_ntop(AF_INET6, &Global_Clatd_Config.plat_subnet, charbuffer, sizeof(charbuffer)));
- logmsg(ANDROID_LOG_DEBUG, "default_pdp_interface = %s",
- Global_Clatd_Config.default_pdp_interface);
-}
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-16 00:05:58 +0000