bmc: add network bridge support

This data handler listens on a TCP port for the image bytes.

Signed-off-by: Benjamin Fair <benjaminfair@google.com>
Change-Id: I388fdd7303c5f8bc93a8f75e97b3abf8adbb81af
diff --git a/bmc/net_handler.cpp b/bmc/net_handler.cpp
new file mode 100644
index 0000000..14ae4fb
--- /dev/null
+++ b/bmc/net_handler.cpp
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2019 Google Inc.
+ *
+ * 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 "net_handler.hpp"
+
+#include <errno.h>
+#include <netinet/in.h>
+#include <poll.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <cstdio>
+
+namespace ipmi_flash
+{
+
+bool NetDataHandler::open()
+{
+    listenFd.reset(::socket(AF_INET6, SOCK_STREAM, 0));
+    if (*listenFd < 0)
+    {
+        std::perror("Failed to create socket");
+        (void)listenFd.release();
+        return false;
+    }
+
+    struct sockaddr_in6 listenAddr;
+    listenAddr.sin6_family = AF_INET6;
+    listenAddr.sin6_port = htons(listenPort);
+    listenAddr.sin6_flowinfo = 0;
+    listenAddr.sin6_addr = in6addr_any;
+    listenAddr.sin6_scope_id = 0;
+
+    if (::bind(*listenFd, (struct sockaddr*)&listenAddr, sizeof(listenAddr)) <
+        0)
+    {
+        std::perror("Failed to bind");
+        return false;
+    }
+
+    if (::listen(*listenFd, 1) < 0)
+    {
+        std::perror("Failed to listen");
+        return false;
+    }
+    return true;
+}
+
+bool NetDataHandler::close()
+{
+    connFd.reset();
+    listenFd.reset();
+
+    return true;
+}
+
+std::vector<std::uint8_t> NetDataHandler::copyFrom(std::uint32_t length)
+{
+    if (!connFd)
+    {
+        struct pollfd fds;
+        fds.fd = *listenFd;
+        fds.events = POLLIN;
+
+        int ret = ::poll(&fds, 1, timeoutS * 1000);
+        if (ret < 0)
+        {
+            std::perror("Failed to poll");
+            return std::vector<uint8_t>();
+        }
+        else if (ret == 0)
+        {
+            fprintf(stderr, "Timed out waiting for connection\n");
+            return std::vector<uint8_t>();
+        }
+        else if (fds.revents != POLLIN)
+        {
+            fprintf(stderr, "Invalid poll state: 0x%x\n", fds.revents);
+            return std::vector<uint8_t>();
+        }
+
+        connFd.reset(::accept(*listenFd, nullptr, nullptr));
+        if (*connFd < 0)
+        {
+            std::perror("Failed to accept connection");
+            (void)connFd.release();
+            return std::vector<uint8_t>();
+        }
+
+        struct timeval tv = {};
+        tv.tv_sec = timeoutS;
+        if (setsockopt(*connFd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0)
+        {
+            std::perror("Failed to set receive timeout");
+            return std::vector<uint8_t>();
+        }
+    }
+
+    std::vector<std::uint8_t> data(length);
+
+    std::uint32_t bytesRead = 0;
+    ssize_t ret;
+    do
+    {
+        ret = read(*connFd, data.data() + bytesRead, length - bytesRead);
+        if (ret < 0)
+        {
+            if (errno == EINTR || errno == EAGAIN)
+                continue;
+            std::perror("Failed to read from socket");
+            break;
+        }
+
+        bytesRead += ret;
+    } while (ret > 0 && bytesRead < length);
+
+    if (bytesRead != length)
+    {
+        fprintf(stderr,
+                "Couldn't read full expected amount. Wanted %u but got %u\n",
+                length, bytesRead);
+        data.resize(bytesRead);
+    }
+
+    return data;
+}
+
+bool NetDataHandler::writeMeta(const std::vector<std::uint8_t>& configuration)
+{
+    // TODO: have the host tool send the expected IP address that it will
+    // connect from
+    return true;
+}
+
+std::vector<std::uint8_t> NetDataHandler::readMeta()
+{
+    return std::vector<std::uint8_t>();
+}
+
+} // namespace ipmi_flash