Initial work

external/android-emugl/shared/emugl/common/sockets.cpp

@@ -0,0 +1,247 @@
+// Copyright (C) 2014 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.
+
+#include "emugl/common/sockets.h"
+
+#include <errno.h>
+
+#ifdef _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#endif
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+namespace emugl {
+
+namespace {
+
+static void socketSetDontLinger(int s) {
+#ifdef _WIN32
+  // TODO: Verify default behavior on WINDOWS
+#else
+    // Ungraceful shutdown, no reason to linger at all
+    struct linger so_linger;
+    so_linger.l_onoff  = 1;
+    so_linger.l_linger = 0;
+    if(setsockopt(s, SOL_SOCKET, SO_LINGER, &so_linger, sizeof so_linger) < 0)
+      perror("Setting socket option SO_LINGER={on, 0} failed");
+#endif
+}
+
+static void socketSetReuseAddress(int s) {
+#ifdef _WIN32
+    // The default behaviour on Windows is equivalent to SO_REUSEADDR
+    // so we don't need to set this option. Moreover, one should never
+    // set this option with WinSock because it's badly implemented and
+    // generates a huge security issue. See:
+    // http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621(v=vs.85).aspx
+#else
+    int val = 1;
+    if(setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
+      perror("Setting socket option SO_REUSEADDR failed");
+#endif
+}
+
+// Helper union to store a socket address.
+struct SockAddr {
+    socklen_t len;
+    union {
+        sockaddr generic;
+        sockaddr_in inet;
+#ifndef _WIN32
+        sockaddr_un local;
+#endif
+    };
+
+    int getFamily() const { return generic.sa_family; }
+
+    void initEmpty() {
+        ::memset(this, 0, sizeof(*this));
+        this->len = static_cast<socklen_t>(sizeof(*this));
+    }
+
+    int initFromInet(uint32_t ip_address, int port) {
+        if (port < 0 || port >= 65536)
+            return -EINVAL;
+
+        ::memset(this, 0, sizeof(*this));
+        this->inet.sin_family = AF_INET;
+        this->inet.sin_port = htons(port);
+        this->inet.sin_addr.s_addr = htonl(ip_address);
+        this->len = sizeof(this->inet);
+        return 0;
+    }
+
+    int initFromLocalhost(int port) {
+        return initFromInet(0x7f000001, port);
+    }
+
+#ifndef _WIN32
+    // Initialize the SockAddr from a Unix path. Returns 0 on success,
+    // or -errno code on failure.
+    int initFromUnixPath(const char* path) {
+        if (!path || !path[0])
+            return -EINVAL;
+
+        size_t pathLen = ::strlen(path);
+        if (pathLen >= sizeof(local.sun_path))
+            return -E2BIG;
+
+        ::memset(this, 0, sizeof(*this));
+        this->local.sun_family = AF_LOCAL;
+        ::memcpy(this->local.sun_path, path, pathLen + 1U);
+        this->len = pathLen + offsetof(sockaddr_un, sun_path);
+        return 0;
+    }
+#endif
+};
+
+int socketBindInternal(const SockAddr* addr, int socketType) {
+    int s = ::socket(addr->getFamily(), socketType, 0);
+    if (s < 0) {
+        perror("Could not create socket to bind");
+        return -errno;
+    }
+
+    socketSetDontLinger(s);
+    socketSetReuseAddress(s);
+
+    // Bind to the socket.
+    if (::bind(s, &addr->generic, addr->len) < 0 ||
+        ::listen(s, 5) < 0) {
+        int ret = -errno;
+        perror("Could not bind or listen to socket");
+        ::close(s);
+        return ret;
+    }
+
+    return s;
+}
+
+int socketConnectInternal(const SockAddr* addr, int socketType) {
+    int s = ::socket(addr->getFamily(), socketType, 0);
+    if (s < 0) {
+        perror("Could not create socket to connect");
+        return -errno;
+    }
+
+    socketSetDontLinger(s);
+    socketSetReuseAddress(s);
+
+    int ret;
+    do {
+        ret = ::connect(s, &addr->generic, addr->len);
+    } while (ret < 0 && errno == EINTR);
+
+    if (ret < 0) {
+        ret = -errno;
+        ::close(s);
+        return ret;
+    }
+
+    return s;
+}
+
+}  // namespace
+
+void socketTcpDisableNagle(int s) {
+    // disable Nagle algorithm to improve bandwidth of small
+    // packets which are quite common in our implementation.
+#ifdef _WIN32
+    DWORD  flag;
+#else
+    int    flag;
+#endif
+    flag = 1;
+    setsockopt(s, IPPROTO_TCP, TCP_NODELAY,
+               (const char*)&flag, sizeof(flag));
+}
+
+int socketGetPort(int s) {
+    SockAddr addr;
+    addr.initEmpty();
+    if (getsockname(s, &addr.generic, &addr.len) < 0) {
+        return -errno;
+    }
+    switch (addr.generic.sa_family) {
+        case AF_INET:
+            return ntohs(addr.inet.sin_port);
+        default:
+            ;
+    }
+    return -EINVAL;
+}
+
+#ifndef _WIN32
+int socketLocalServer(const char* path, int socketType) {
+    SockAddr addr;
+    int ret = addr.initFromUnixPath(path);
+    if (ret < 0) {
+        return ret;
+    }
+    return socketBindInternal(&addr, socketType);
+}
+
+int socketLocalClient(const char* path, int socketType) {
+    SockAddr addr;
+    int ret = addr.initFromUnixPath(path);
+    if (ret < 0) {
+        return ret;
+    }
+    return socketConnectInternal(&addr, socketType);
+}
+#endif  // !_WIN32
+
+int socketTcpLoopbackServer(int port, int socketType) {
+    SockAddr addr;
+    int ret = addr.initFromLocalhost(port);
+    if (ret < 0) {
+        return ret;
+    }
+    return socketBindInternal(&addr, socketType);
+}
+
+int socketTcpLoopbackClient(int port, int socketType) {
+    SockAddr addr;
+    int ret = addr.initFromLocalhost(port);
+    if (ret < 0) {
+        return ret;
+    }
+    return socketConnectInternal(&addr, socketType);
+}
+
+int socketTcpClient(const char* hostname, int port, int socketType) {
+    // TODO(digit): Implement this.
+    return -ENOSYS;
+}
+
+int socketAccept(int serverSocket) {
+    int ret;
+    do {
+        ret = ::accept(serverSocket, NULL, NULL);
+    } while (ret < 0 && errno == EINTR);
+    return ret;
+}
+
+}  // namespace emugl