clatutils - code cleanup
add const, etc.
Test: TreeHugger
Bug: 265591307
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I8daa05891759370f6f5d7369a283d8ffc543a790
diff --git a/service/native/libs/libclat/clatutils.cpp b/service/native/libs/libclat/clatutils.cpp
index c6a9781..2723933 100644
--- a/service/native/libs/libclat/clatutils.cpp
+++ b/service/native/libs/libclat/clatutils.cpp
@@ -33,11 +33,9 @@
namespace net {
namespace clat {
-bool isIpv4AddressFree(in_addr_t addr) {
- int s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
- if (s == -1) {
- return 0;
- }
+bool isIpv4AddressFree(const in_addr_t addr) {
+ const 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 then the address is already assigned to the system and we can't use it.
@@ -47,9 +45,10 @@
.sin_addr = {addr},
};
socklen_t len = sizeof(sin);
- bool 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;
+ const bool inuse = !connect(s, (struct sockaddr*)&sin, sizeof(sin)) &&
+ !getsockname(s, (struct sockaddr*)&sin, &len) &&
+ len == (socklen_t)sizeof(sin) &&
+ sin.sin_addr.s_addr == addr;
close(s);
return !inuse;
@@ -59,36 +58,30 @@
// 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 selectIpv4Address(const in_addr ip, int16_t prefixlen) {
+in_addr_t selectIpv4Address(const in_addr ip, const int16_t prefixlen) {
return selectIpv4AddressInternal(ip, prefixlen, isIpv4AddressFree);
}
// Only allow testing to use this function directly. Otherwise call selectIpv4Address(ip, pfxlen)
// which has applied valid isIpv4AddressFree function pointer.
-in_addr_t selectIpv4AddressInternal(const in_addr ip, int16_t prefixlen,
- isIpv4AddrFreeFn isIpv4AddressFreeFunc) {
+in_addr_t selectIpv4AddressInternal(const in_addr ip, const int16_t prefixlen,
+ const isIpv4AddrFreeFn isIpv4AddressFreeFunc) {
// Impossible! Only test allows to apply fn.
- if (isIpv4AddressFreeFunc == nullptr) {
- return INADDR_NONE;
- }
+ if (isIpv4AddressFreeFunc == nullptr) return INADDR_NONE;
// Don't accept prefixes that are too large because we scan addresses one by one.
- if (prefixlen < 16 || prefixlen > 32) {
- return INADDR_NONE;
- }
+ if (prefixlen < 16 || prefixlen > 32) return INADDR_NONE;
// 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;
+ const uint32_t mask = 0xffffffff >> (32 - prefixlen) << (32 - prefixlen);
+ uint32_t ipv4 = ntohl(ip.s_addr);
+ const uint32_t first_ipv4 = ipv4;
+ const uint32_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 (isIpv4AddressFreeFunc(htonl(ipv4))) {
- return htonl(ipv4);
- }
+ if (isIpv4AddressFreeFunc(htonl(ipv4))) return htonl(ipv4);
ipv4 = prefix | ((ipv4 + 1) & ~mask);
} while (ipv4 != first_ipv4);
@@ -96,7 +89,7 @@
}
// Alters the bits in the IPv6 address to make them checksum neutral with v4 and nat64Prefix.
-void makeChecksumNeutral(in6_addr* v6, const in_addr v4, const in6_addr& nat64Prefix) {
+void makeChecksumNeutral(in6_addr* const v6, const in_addr v4, const in6_addr& nat64Prefix) {
// Fill last 8 bytes of IPv6 address with random bits.
arc4random_buf(&v6->s6_addr[8], 8);
@@ -118,33 +111,35 @@
}
// Picks a random interface ID that is checksum neutral with the IPv4 address and the NAT64 prefix.
-int generateIpv6Address(const char* iface, const in_addr v4, const in6_addr& nat64Prefix,
- in6_addr* v6, uint32_t mark) {
- int s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+int generateIpv6Address(const char* const iface, const in_addr v4, const in6_addr& nat64Prefix,
+ in6_addr* const v6, const uint32_t mark) {
+ const int s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (s == -1) return -errno;
// Socket's mark affects routing decisions (network selection)
// An fwmark is necessary for clat to bypass the VPN during initialization.
if (setsockopt(s, SOL_SOCKET, SO_MARK, &mark, sizeof(mark))) {
- int ret = errno;
- ALOGE("setsockopt(SOL_SOCKET, SO_MARK) failed: %s", strerror(errno));
+ const int err = errno;
+ ALOGE("setsockopt(SOL_SOCKET, SO_MARK) failed: %s", strerror(err));
close(s);
- return -ret;
+ return -err;
}
- if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, iface, strlen(iface) + 1) == -1) {
+ if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, iface, strlen(iface) + 1)) {
+ const int err = errno;
+ ALOGE("setsockopt(SOL_SOCKET, SO_BINDTODEVICE, '%s') failed: %s", iface, strerror(err));
close(s);
- return -errno;
+ return -err;
}
sockaddr_in6 sin6 = {.sin6_family = AF_INET6, .sin6_addr = nat64Prefix};
- if (connect(s, reinterpret_cast<struct sockaddr*>(&sin6), sizeof(sin6)) == -1) {
+ if (connect(s, reinterpret_cast<struct sockaddr*>(&sin6), sizeof(sin6))) {
close(s);
return -errno;
}
socklen_t len = sizeof(sin6);
- if (getsockname(s, reinterpret_cast<struct sockaddr*>(&sin6), &len) == -1) {
+ if (getsockname(s, reinterpret_cast<struct sockaddr*>(&sin6), &len)) {
close(s);
return -errno;
}
@@ -163,21 +158,22 @@
return 0;
}
-int detect_mtu(const struct in6_addr* plat_subnet, uint32_t plat_suffix, uint32_t mark) {
+int detect_mtu(const struct in6_addr* const plat_subnet, const uint32_t plat_suffix,
+ const uint32_t mark) {
// Create an IPv6 UDP socket.
- int s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+ const int s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (s < 0) {
- int ret = errno;
- ALOGE("socket(AF_INET6, SOCK_DGRAM, 0) failed: %s", strerror(errno));
- return -ret;
+ const int err = errno;
+ ALOGE("socket(AF_INET6, SOCK_DGRAM, 0) failed: %s", strerror(err));
+ return -err;
}
// Socket's mark affects routing decisions (network selection)
if (setsockopt(s, SOL_SOCKET, SO_MARK, &mark, sizeof(mark))) {
- int ret = errno;
- ALOGE("setsockopt(SOL_SOCKET, SO_MARK) failed: %s", strerror(errno));
+ const int err = errno;
+ ALOGE("setsockopt(SOL_SOCKET, SO_MARK) failed: %s", strerror(err));
close(s);
- return -ret;
+ return -err;
}
// Try to connect udp socket to plat_subnet(96 bits):plat_suffix(32 bits)
@@ -187,20 +183,20 @@
};
dst.sin6_addr.s6_addr32[3] = plat_suffix;
if (connect(s, (struct sockaddr*)&dst, sizeof(dst))) {
- int ret = errno;
- ALOGE("connect() failed: %s", strerror(errno));
+ const int err = errno;
+ ALOGE("connect() failed: %s", strerror(err));
close(s);
- return -ret;
+ return -err;
}
// Fetch the socket's IPv6 mtu - this is effectively fetching mtu from routing table
int mtu;
socklen_t sz_mtu = sizeof(mtu);
if (getsockopt(s, SOL_IPV6, IPV6_MTU, &mtu, &sz_mtu)) {
- int ret = errno;
- ALOGE("getsockopt(SOL_IPV6, IPV6_MTU) failed: %s", strerror(errno));
+ const int err = errno;
+ ALOGE("getsockopt(SOL_IPV6, IPV6_MTU) failed: %s", strerror(err));
close(s);
- return -ret;
+ return -err;
}
if (sz_mtu != sizeof(mtu)) {
ALOGE("getsockopt(SOL_IPV6, IPV6_MTU) returned unexpected size: %d", sz_mtu);
@@ -219,8 +215,8 @@
* ifindex - index of interface to add the filter to
* returns: 0 on success, -errno on failure
*/
-int configure_packet_socket(int sock, in6_addr* addr, int ifindex) {
- uint32_t* ipv6 = addr->s6_addr32;
+int configure_packet_socket(const int sock, const in6_addr* const addr, const int ifindex) {
+ const uint32_t* ipv6 = addr->s6_addr32;
// clang-format off
struct sock_filter filter_code[] = {
@@ -244,9 +240,9 @@
struct sock_fprog filter = {sizeof(filter_code) / sizeof(filter_code[0]), filter_code};
if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter))) {
- int res = errno;
- ALOGE("attach packet filter failed: %s", strerror(errno));
- return -res;
+ const int err = errno;
+ ALOGE("attach packet filter failed: %s", strerror(err));
+ return -err;
}
struct sockaddr_ll sll = {
@@ -257,9 +253,9 @@
PACKET_OTHERHOST, // The 464xlat IPv6 address is not assigned to the kernel.
};
if (bind(sock, (struct sockaddr*)&sll, sizeof(sll))) {
- int res = errno;
- ALOGE("binding packet socket: %s", strerror(errno));
- return -res;
+ const int err = errno;
+ ALOGE("binding packet socket: %s", strerror(err));
+ return -err;
}
return 0;