diff --git a/src/libraries/Native/Unix/System.Native/CMakeLists.txt b/src/libraries/Native/Unix/System.Native/CMakeLists.txt index 613ce0f1e7b64..9e490e9f0e98e 100644 --- a/src/libraries/Native/Unix/System.Native/CMakeLists.txt +++ b/src/libraries/Native/Unix/System.Native/CMakeLists.txt @@ -79,7 +79,9 @@ include(${CMAKE_CURRENT_LIST_DIR}/extra_libs.cmake) set(NATIVE_LIBS_EXTRA) append_extra_system_libs(NATIVE_LIBS_EXTRA) -if (CLR_CMAKE_TARGET_ANDROID) +if (CLR_CMAKE_TARGET_ANDROID AND NOT HAVE_GETIFADDRS) + add_definitions(-DANDROID_GETIFADDRS_WORKAROUND) + add_compile_options(-Wno-gnu-zero-variadic-macro-arguments) list (APPEND NATIVE_LIBS_EXTRA -llog) diff --git a/src/libraries/Native/Unix/System.Native/pal_interfaceaddresses.c b/src/libraries/Native/Unix/System.Native/pal_interfaceaddresses.c index 22165b6520688..0a92305bcbd48 100644 --- a/src/libraries/Native/Unix/System.Native/pal_interfaceaddresses.c +++ b/src/libraries/Native/Unix/System.Native/pal_interfaceaddresses.c @@ -11,11 +11,12 @@ #include #include #include -#if HAVE_GETIFADDRS && !defined(TARGET_ANDROID) +#if HAVE_GETIFADDRS || defined(ANDROID_GETIFADDRS_WORKAROUND) #include #endif -#ifdef TARGET_ANDROID -#include "pal_ifaddrs.h" +#ifdef ANDROID_GETIFADDRS_WORKAROUND +#include +#include #endif #include #include @@ -100,12 +101,45 @@ static inline uint8_t mask2prefix(uint8_t* mask, int length) return len; } +#ifdef ANDROID_GETIFADDRS_WORKAROUND +// Try to load the getifaddrs and freeifaddrs functions manually. +// This workaround is necessary on Android prior to API 24 and it can be removed once +// we drop support for earlier Android versions. +static int (*getifaddrs)(struct ifaddrs**) = NULL; +static void (*freeifaddrs)(struct ifaddrs*) = NULL; + +static void try_loading_getifaddrs() +{ + void *libc = dlopen("libc.so", RTLD_NOW); + if (libc) + { + getifaddrs = (int (*)(struct ifaddrs**)) dlsym(libc, "getifaddrs"); + freeifaddrs = (void (*)(struct ifaddrs*)) dlsym(libc, "freeifaddrs"); + } +} + +static bool ensure_getifaddrs_is_loaded() +{ + static pthread_once_t getifaddrs_is_loaded = PTHREAD_ONCE_INIT; + pthread_once(&getifaddrs_is_loaded, try_loading_getifaddrs); + return getifaddrs != NULL && freeifaddrs != NULL; +} +#endif + int32_t SystemNative_EnumerateInterfaceAddresses(void* context, IPv4AddressFound onIpv4Found, IPv6AddressFound onIpv6Found, LinkLayerAddressFound onLinkLayerFound) { -#if HAVE_GETIFADDRS || defined(TARGET_ANDROID) +#ifdef ANDROID_GETIFADDRS_WORKAROUND + if (!ensure_getifaddrs_is_loaded()) + { + errno = ENOTSUP; + return -1; + } +#endif + +#if HAVE_GETIFADDRS || defined(ANDROID_GETIFADDRS_WORKAROUND) struct ifaddrs* headAddr; if (getifaddrs(&headAddr) == -1) { @@ -250,7 +284,15 @@ int32_t SystemNative_EnumerateInterfaceAddresses(void* context, int32_t SystemNative_GetNetworkInterfaces(int32_t * interfaceCount, NetworkInterfaceInfo **interfaceList, int32_t * addressCount, IpAddressInfo **addressList ) { -#if HAVE_GETIFADDRS || defined(TARGET_ANDROID) +#ifdef ANDROID_GETIFADDRS_WORKAROUND + if (!ensure_getifaddrs_is_loaded()) + { + errno = ENOTSUP; + return -1; + } +#endif + +#if HAVE_GETIFADDRS || defined(ANDROID_GETIFADDRS_WORKAROUND) struct ifaddrs* head; // Pointer to block allocated by getifaddrs(). struct ifaddrs* ifaddrsEntry; IpAddressInfo *ai; @@ -289,7 +331,16 @@ int32_t SystemNative_GetNetworkInterfaces(int32_t * interfaceCount, NetworkInter // To save allocation need for separate free() we will allocate one memory chunk // where we first write out NetworkInterfaceInfo entries immediately followed by // IpAddressInfo list. - void * memoryBlock = calloc((size_t)count, sizeof(NetworkInterfaceInfo)); +#ifdef TARGET_ANDROID + // Since Android API 30, getifaddrs returns only AF_INET and AF_INET6 addresses and we do not + // get any AF_PACKET addresses and so count == ip4count + ip6count. We need to make sure that + // the memoryBlock is large enough to hold all interfaces (up to `count` entries) and all + // addresses (ip4count + ip6count) without any overlap between interfaceList and addressList. + int entriesCount = count + ip4count + ip6count; +#else + int entriesCount = count; +#endif + void * memoryBlock = calloc((size_t)entriesCount, sizeof(NetworkInterfaceInfo)); if (memoryBlock == NULL) { errno = ENOMEM; @@ -300,7 +351,7 @@ int32_t SystemNative_GetNetworkInterfaces(int32_t * interfaceCount, NetworkInter ifaddrsEntry = head; *interfaceList = nii = (NetworkInterfaceInfo*)memoryBlock; // address of first IpAddressInfo after all NetworkInterfaceInfo entries. - *addressList = ai = (IpAddressInfo*)(nii + (count - ip4count - ip6count)); + *addressList = ai = (IpAddressInfo*)(nii + (entriesCount - ip4count - ip6count)); while (ifaddrsEntry != NULL) { @@ -324,7 +375,7 @@ int32_t SystemNative_GetNetworkInterfaces(int32_t * interfaceCount, NetworkInter memcpy(nii->Name, ifaddrsEntry->ifa_name, sizeof(nii->Name)); nii->InterfaceIndex = if_nametoindex(ifaddrsEntry->ifa_name); nii->Speed = -1; - nii->HardwareType = NetworkInterfaceType_Unknown; + nii->HardwareType = ((ifaddrsEntry->ifa_flags & IFF_LOOPBACK) == IFF_LOOPBACK) ? NetworkInterfaceType_Loopback : NetworkInterfaceType_Unknown; // Get operational state and multicast support. if ((ifaddrsEntry->ifa_flags & (IFF_MULTICAST|IFF_ALLMULTI)) != 0)