Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2009 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef IFADDRS_ANDROID_H_included |
| 18 | #define IFADDRS_ANDROID_H_included |
| 19 | |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 20 | #include <arpa/inet.h> |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 21 | #include <cstring> |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 22 | #include <errno.h> |
| 23 | #include <net/if.h> |
| 24 | #include <netinet/in.h> |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 25 | #include <new> |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 26 | #include <sys/ioctl.h> |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 27 | #include <sys/types.h> |
| 28 | #include <sys/socket.h> |
Elliott Hughes | e097295 | 2009-11-23 10:46:02 -0800 | [diff] [blame] | 29 | #include <stdio.h> |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 30 | #include <linux/netlink.h> |
| 31 | #include <linux/rtnetlink.h> |
| 32 | |
| 33 | #include "LocalArray.h" |
| 34 | #include "ScopedFd.h" |
| 35 | |
| 36 | // Android (bionic) doesn't have getifaddrs(3)/freeifaddrs(3). |
| 37 | // We fake it here, so java_net_NetworkInterface.cpp can use that API |
| 38 | // with all the non-portable code being in this file. |
| 39 | |
| 40 | // Source-compatible subset of the BSD struct. |
| 41 | struct ifaddrs { |
| 42 | // Pointer to next struct in list, or NULL at end. |
| 43 | ifaddrs* ifa_next; |
| 44 | |
| 45 | // Interface name. |
| 46 | char* ifa_name; |
| 47 | |
| 48 | // Interface flags. |
| 49 | unsigned int ifa_flags; |
| 50 | |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 51 | // Interface network address. |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 52 | sockaddr* ifa_addr; |
| 53 | |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 54 | // Interface netmask. |
| 55 | sockaddr* ifa_netmask; |
| 56 | |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 57 | ifaddrs(ifaddrs* next) |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 58 | : ifa_next(next), ifa_name(NULL), ifa_flags(0), ifa_addr(NULL), ifa_netmask(NULL) |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 59 | { |
| 60 | } |
| 61 | |
| 62 | ~ifaddrs() { |
| 63 | delete ifa_next; |
| 64 | delete[] ifa_name; |
| 65 | delete ifa_addr; |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 66 | delete ifa_netmask; |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 67 | } |
| 68 | |
| 69 | // Sadly, we can't keep the interface index for portability with BSD. |
| 70 | // We'll have to keep the name instead, and re-query the index when |
| 71 | // we need it later. |
| 72 | bool setNameAndFlagsByIndex(int interfaceIndex) { |
| 73 | // Get the name. |
| 74 | char buf[IFNAMSIZ]; |
| 75 | char* name = if_indextoname(interfaceIndex, buf); |
| 76 | if (name == NULL) { |
| 77 | return false; |
| 78 | } |
| 79 | ifa_name = new char[strlen(name) + 1]; |
| 80 | strcpy(ifa_name, name); |
| 81 | |
| 82 | // Get the flags. |
| 83 | ScopedFd fd(socket(AF_INET, SOCK_DGRAM, 0)); |
| 84 | if (fd.get() == -1) { |
| 85 | return false; |
| 86 | } |
| 87 | ifreq ifr; |
| 88 | memset(&ifr, 0, sizeof(ifr)); |
| 89 | strcpy(ifr.ifr_name, name); |
| 90 | int rc = ioctl(fd.get(), SIOCGIFFLAGS, &ifr); |
| 91 | if (rc == -1) { |
| 92 | return false; |
| 93 | } |
| 94 | ifa_flags = ifr.ifr_flags; |
| 95 | return true; |
| 96 | } |
| 97 | |
| 98 | // Netlink gives us the address family in the header, and the |
| 99 | // sockaddr_in or sockaddr_in6 bytes as the payload. We need to |
| 100 | // stitch the two bits together into the sockaddr that's part of |
| 101 | // our portable interface. |
| 102 | void setAddress(int family, void* data, size_t byteCount) { |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 103 | // Set the address proper... |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 104 | sockaddr_storage* ss = new sockaddr_storage; |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 105 | memset(ss, 0, sizeof(*ss)); |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 106 | ifa_addr = reinterpret_cast<sockaddr*>(ss); |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 107 | ss->ss_family = family; |
| 108 | uint8_t* dst = sockaddrBytes(family, ss); |
| 109 | memcpy(dst, data, byteCount); |
| 110 | } |
| 111 | |
| 112 | // Netlink gives us the prefix length as a bit count. We need to turn |
| 113 | // that into a BSD-compatible netmask represented by a sockaddr*. |
| 114 | void setNetmask(int family, size_t prefixLength) { |
| 115 | // ...and work out the netmask from the prefix length. |
| 116 | sockaddr_storage* ss = new sockaddr_storage; |
| 117 | memset(ss, 0, sizeof(*ss)); |
| 118 | ifa_netmask = reinterpret_cast<sockaddr*>(ss); |
| 119 | ss->ss_family = family; |
| 120 | uint8_t* dst = sockaddrBytes(family, ss); |
| 121 | memset(dst, 0xff, prefixLength / 8); |
| 122 | if ((prefixLength % 8) != 0) { |
| 123 | dst[prefixLength/8] = (0xff << (8 - (prefixLength % 8))); |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | // Returns a pointer to the first byte in the address data (which is |
| 128 | // stored in network byte order). |
| 129 | uint8_t* sockaddrBytes(int family, sockaddr_storage* ss) { |
| 130 | if (family == AF_INET) { |
| 131 | sockaddr_in* ss4 = reinterpret_cast<sockaddr_in*>(ss); |
| 132 | return reinterpret_cast<uint8_t*>(&ss4->sin_addr); |
| 133 | } else if (family == AF_INET6) { |
| 134 | sockaddr_in6* ss6 = reinterpret_cast<sockaddr_in6*>(ss); |
| 135 | return reinterpret_cast<uint8_t*>(&ss6->sin6_addr); |
| 136 | } |
| 137 | return NULL; |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 138 | } |
Elliott Hughes | 7ca6fd0 | 2010-03-29 20:51:48 -0700 | [diff] [blame] | 139 | |
| 140 | private: |
| 141 | // Disallow copy and assignment. |
| 142 | ifaddrs(const ifaddrs&); |
| 143 | void operator=(const ifaddrs&); |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 144 | }; |
| 145 | |
| 146 | // FIXME: use iovec instead. |
| 147 | struct addrReq_struct { |
| 148 | nlmsghdr netlinkHeader; |
| 149 | ifaddrmsg msg; |
| 150 | }; |
| 151 | |
| 152 | inline bool sendNetlinkMessage(int fd, const void* data, size_t byteCount) { |
| 153 | ssize_t sentByteCount = TEMP_FAILURE_RETRY(send(fd, data, byteCount, 0)); |
| 154 | return (sentByteCount == static_cast<ssize_t>(byteCount)); |
| 155 | } |
| 156 | |
| 157 | inline ssize_t recvNetlinkMessage(int fd, char* buf, size_t byteCount) { |
| 158 | return TEMP_FAILURE_RETRY(recv(fd, buf, byteCount, 0)); |
| 159 | } |
| 160 | |
| 161 | // Source-compatible with the BSD function. |
| 162 | inline int getifaddrs(ifaddrs** result) { |
| 163 | // Simplify cleanup for callers. |
| 164 | *result = NULL; |
| 165 | |
| 166 | // Create a netlink socket. |
| 167 | ScopedFd fd(socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)); |
| 168 | if (fd.get() < 0) { |
| 169 | return -1; |
| 170 | } |
| 171 | |
| 172 | // Ask for the address information. |
| 173 | addrReq_struct addrRequest; |
| 174 | memset(&addrRequest, 0, sizeof(addrRequest)); |
| 175 | addrRequest.netlinkHeader.nlmsg_flags = NLM_F_REQUEST | NLM_F_MATCH; |
| 176 | addrRequest.netlinkHeader.nlmsg_type = RTM_GETADDR; |
| 177 | addrRequest.netlinkHeader.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(addrRequest))); |
| 178 | addrRequest.msg.ifa_family = AF_UNSPEC; // All families. |
| 179 | addrRequest.msg.ifa_index = 0; // All interfaces. |
| 180 | if (!sendNetlinkMessage(fd.get(), &addrRequest, addrRequest.netlinkHeader.nlmsg_len)) { |
| 181 | return -1; |
| 182 | } |
| 183 | |
| 184 | // Read the responses. |
| 185 | LocalArray<0> buf(65536); // We don't necessarily have std::vector. |
| 186 | ssize_t bytesRead; |
| 187 | while ((bytesRead = recvNetlinkMessage(fd.get(), &buf[0], buf.size())) > 0) { |
| 188 | nlmsghdr* hdr = reinterpret_cast<nlmsghdr*>(&buf[0]); |
Brian Carlstrom | 44e0e56 | 2010-05-06 23:44:16 -0700 | [diff] [blame^] | 189 | for (; NLMSG_OK(hdr, (size_t)bytesRead); hdr = NLMSG_NEXT(hdr, bytesRead)) { |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 190 | switch (hdr->nlmsg_type) { |
| 191 | case NLMSG_DONE: |
| 192 | return 0; |
| 193 | case NLMSG_ERROR: |
| 194 | return -1; |
| 195 | case RTM_NEWADDR: |
| 196 | { |
| 197 | ifaddrmsg* address = reinterpret_cast<ifaddrmsg*>(NLMSG_DATA(hdr)); |
| 198 | rtattr* rta = IFA_RTA(address); |
| 199 | size_t ifaPayloadLength = IFA_PAYLOAD(hdr); |
| 200 | while (RTA_OK(rta, ifaPayloadLength)) { |
Elliott Hughes | a5fd116 | 2010-04-21 12:48:25 -0700 | [diff] [blame] | 201 | if (rta->rta_type == IFA_LOCAL) { |
Elliott Hughes | e097295 | 2009-11-23 10:46:02 -0800 | [diff] [blame] | 202 | int family = address->ifa_family; |
| 203 | if (family == AF_INET || family == AF_INET6) { |
| 204 | *result = new ifaddrs(*result); |
| 205 | if (!(*result)->setNameAndFlagsByIndex(address->ifa_index)) { |
| 206 | return -1; |
| 207 | } |
| 208 | (*result)->setAddress(family, RTA_DATA(rta), RTA_PAYLOAD(rta)); |
Elliott Hughes | d2af45a | 2010-03-04 15:12:37 -0800 | [diff] [blame] | 209 | (*result)->setNetmask(family, address->ifa_prefixlen); |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 210 | } |
Elliott Hughes | b5fc5ec | 2009-11-19 18:32:43 -0800 | [diff] [blame] | 211 | } |
| 212 | rta = RTA_NEXT(rta, ifaPayloadLength); |
| 213 | } |
| 214 | } |
| 215 | break; |
| 216 | } |
| 217 | } |
| 218 | } |
| 219 | // We only get here if recv fails before we see a NLMSG_DONE. |
| 220 | return -1; |
| 221 | } |
| 222 | |
| 223 | // Source-compatible with the BSD function. |
| 224 | inline void freeifaddrs(ifaddrs* addresses) { |
| 225 | delete addresses; |
| 226 | } |
| 227 | |
| 228 | #endif // IFADDRS_ANDROID_H_included |