| /* |
| * Copyright (C) 2009 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef IFADDRS_ANDROID_H_included |
| #define IFADDRS_ANDROID_H_included |
| |
| #include <arpa/inet.h> |
| #include <cstring> |
| #include <errno.h> |
| #include <net/if.h> |
| #include <netinet/in.h> |
| #include <new> |
| #include <sys/ioctl.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <stdio.h> |
| #include <linux/netlink.h> |
| #include <linux/rtnetlink.h> |
| |
| #include "LocalArray.h" |
| #include "ScopedFd.h" |
| |
| // Android (bionic) doesn't have getifaddrs(3)/freeifaddrs(3). |
| // We fake it here, so java_net_NetworkInterface.cpp can use that API |
| // with all the non-portable code being in this file. |
| |
| // Source-compatible subset of the BSD struct. |
| struct ifaddrs { |
| // Pointer to next struct in list, or NULL at end. |
| ifaddrs* ifa_next; |
| |
| // Interface name. |
| char* ifa_name; |
| |
| // Interface flags. |
| unsigned int ifa_flags; |
| |
| // Interface network address. |
| sockaddr* ifa_addr; |
| |
| // Interface netmask. |
| sockaddr* ifa_netmask; |
| |
| ifaddrs(ifaddrs* next) |
| : ifa_next(next), ifa_name(NULL), ifa_flags(0), ifa_addr(NULL), ifa_netmask(NULL) |
| { |
| } |
| |
| ~ifaddrs() { |
| delete ifa_next; |
| delete[] ifa_name; |
| delete ifa_addr; |
| delete ifa_netmask; |
| } |
| |
| // Sadly, we can't keep the interface index for portability with BSD. |
| // We'll have to keep the name instead, and re-query the index when |
| // we need it later. |
| bool setNameAndFlagsByIndex(int interfaceIndex) { |
| // Get the name. |
| char buf[IFNAMSIZ]; |
| char* name = if_indextoname(interfaceIndex, buf); |
| if (name == NULL) { |
| return false; |
| } |
| ifa_name = new char[strlen(name) + 1]; |
| strcpy(ifa_name, name); |
| |
| // Get the flags. |
| ScopedFd fd(socket(AF_INET, SOCK_DGRAM, 0)); |
| if (fd.get() == -1) { |
| return false; |
| } |
| ifreq ifr; |
| memset(&ifr, 0, sizeof(ifr)); |
| strcpy(ifr.ifr_name, name); |
| int rc = ioctl(fd.get(), SIOCGIFFLAGS, &ifr); |
| if (rc == -1) { |
| return false; |
| } |
| ifa_flags = ifr.ifr_flags; |
| return true; |
| } |
| |
| // Netlink gives us the address family in the header, and the |
| // sockaddr_in or sockaddr_in6 bytes as the payload. We need to |
| // stitch the two bits together into the sockaddr that's part of |
| // our portable interface. |
| void setAddress(int family, void* data, size_t byteCount) { |
| // Set the address proper... |
| sockaddr_storage* ss = new sockaddr_storage; |
| memset(ss, 0, sizeof(*ss)); |
| ifa_addr = reinterpret_cast<sockaddr*>(ss); |
| ss->ss_family = family; |
| uint8_t* dst = sockaddrBytes(family, ss); |
| memcpy(dst, data, byteCount); |
| } |
| |
| // Netlink gives us the prefix length as a bit count. We need to turn |
| // that into a BSD-compatible netmask represented by a sockaddr*. |
| void setNetmask(int family, size_t prefixLength) { |
| // ...and work out the netmask from the prefix length. |
| sockaddr_storage* ss = new sockaddr_storage; |
| memset(ss, 0, sizeof(*ss)); |
| ifa_netmask = reinterpret_cast<sockaddr*>(ss); |
| ss->ss_family = family; |
| uint8_t* dst = sockaddrBytes(family, ss); |
| memset(dst, 0xff, prefixLength / 8); |
| if ((prefixLength % 8) != 0) { |
| dst[prefixLength/8] = (0xff << (8 - (prefixLength % 8))); |
| } |
| } |
| |
| // Returns a pointer to the first byte in the address data (which is |
| // stored in network byte order). |
| uint8_t* sockaddrBytes(int family, sockaddr_storage* ss) { |
| if (family == AF_INET) { |
| sockaddr_in* ss4 = reinterpret_cast<sockaddr_in*>(ss); |
| return reinterpret_cast<uint8_t*>(&ss4->sin_addr); |
| } else if (family == AF_INET6) { |
| sockaddr_in6* ss6 = reinterpret_cast<sockaddr_in6*>(ss); |
| return reinterpret_cast<uint8_t*>(&ss6->sin6_addr); |
| } |
| return NULL; |
| } |
| |
| private: |
| // Disallow copy and assignment. |
| ifaddrs(const ifaddrs&); |
| void operator=(const ifaddrs&); |
| }; |
| |
| // FIXME: use iovec instead. |
| struct addrReq_struct { |
| nlmsghdr netlinkHeader; |
| ifaddrmsg msg; |
| }; |
| |
| inline bool sendNetlinkMessage(int fd, const void* data, size_t byteCount) { |
| ssize_t sentByteCount = TEMP_FAILURE_RETRY(send(fd, data, byteCount, 0)); |
| return (sentByteCount == static_cast<ssize_t>(byteCount)); |
| } |
| |
| inline ssize_t recvNetlinkMessage(int fd, char* buf, size_t byteCount) { |
| return TEMP_FAILURE_RETRY(recv(fd, buf, byteCount, 0)); |
| } |
| |
| // Source-compatible with the BSD function. |
| inline int getifaddrs(ifaddrs** result) { |
| // Simplify cleanup for callers. |
| *result = NULL; |
| |
| // Create a netlink socket. |
| ScopedFd fd(socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)); |
| if (fd.get() < 0) { |
| return -1; |
| } |
| |
| // Ask for the address information. |
| addrReq_struct addrRequest; |
| memset(&addrRequest, 0, sizeof(addrRequest)); |
| addrRequest.netlinkHeader.nlmsg_flags = NLM_F_REQUEST | NLM_F_MATCH; |
| addrRequest.netlinkHeader.nlmsg_type = RTM_GETADDR; |
| addrRequest.netlinkHeader.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(addrRequest))); |
| addrRequest.msg.ifa_family = AF_UNSPEC; // All families. |
| addrRequest.msg.ifa_index = 0; // All interfaces. |
| if (!sendNetlinkMessage(fd.get(), &addrRequest, addrRequest.netlinkHeader.nlmsg_len)) { |
| return -1; |
| } |
| |
| // Read the responses. |
| LocalArray<0> buf(65536); // We don't necessarily have std::vector. |
| ssize_t bytesRead; |
| while ((bytesRead = recvNetlinkMessage(fd.get(), &buf[0], buf.size())) > 0) { |
| nlmsghdr* hdr = reinterpret_cast<nlmsghdr*>(&buf[0]); |
| for (; NLMSG_OK(hdr, (size_t)bytesRead); hdr = NLMSG_NEXT(hdr, bytesRead)) { |
| switch (hdr->nlmsg_type) { |
| case NLMSG_DONE: |
| return 0; |
| case NLMSG_ERROR: |
| return -1; |
| case RTM_NEWADDR: |
| { |
| ifaddrmsg* address = reinterpret_cast<ifaddrmsg*>(NLMSG_DATA(hdr)); |
| rtattr* rta = IFA_RTA(address); |
| size_t ifaPayloadLength = IFA_PAYLOAD(hdr); |
| while (RTA_OK(rta, ifaPayloadLength)) { |
| if (rta->rta_type == IFA_LOCAL) { |
| int family = address->ifa_family; |
| if (family == AF_INET || family == AF_INET6) { |
| *result = new ifaddrs(*result); |
| if (!(*result)->setNameAndFlagsByIndex(address->ifa_index)) { |
| return -1; |
| } |
| (*result)->setAddress(family, RTA_DATA(rta), RTA_PAYLOAD(rta)); |
| (*result)->setNetmask(family, address->ifa_prefixlen); |
| } |
| } |
| rta = RTA_NEXT(rta, ifaPayloadLength); |
| } |
| } |
| break; |
| } |
| } |
| } |
| // We only get here if recv fails before we see a NLMSG_DONE. |
| return -1; |
| } |
| |
| // Source-compatible with the BSD function. |
| inline void freeifaddrs(ifaddrs* addresses) { |
| delete addresses; |
| } |
| |
| #endif // IFADDRS_ANDROID_H_included |