libcutils/fastboot: improve multi-buffer write.

Fixes libcutils multi-buffer write interface to be more friendly and
hooks into it from the fastboot Socket class.

Bug: http://b/26558551
Change-Id: Ibb3a8428fc379755602de52722c1260f9e345bc0

1 files changed, 79 insertions, 0 deletions

diff --git a/libcutils/sockets_unix.cpp b/libcutils/sockets_unix.cpp
new file mode 100644
index 000000000..8747d696f
--- /dev/null
+++ b/libcutils/sockets_unix.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2011 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 <cutils/sockets.h>
+
+#include <sys/uio.h>
+
+#include <log/log.h>
+
+#if defined(__ANDROID__)
+/* For the socket trust (credentials) check */
+#include <private/android_filesystem_config.h>
+#define __android_unused
+#else
+#define __android_unused __attribute__((__unused__))
+#endif
+
+bool socket_peer_is_trusted(int fd __android_unused) {
+#if defined(__ANDROID__)
+    ucred cr;
+    socklen_t len = sizeof(cr);
+    int n = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+
+    if (n != 0) {
+        ALOGE("could not get socket credentials: %s\n", strerror(errno));
+        return false;
+    }
+
+    if ((cr.uid != AID_ROOT) && (cr.uid != AID_SHELL)) {
+        ALOGE("untrusted userid on other end of socket: userid %d\n", cr.uid);
+        return false;
+    }
+#endif
+
+    return true;
+}
+
+int socket_close(int sock) {
+    return close(sock);
+}
+
+int socket_set_receive_timeout(cutils_socket_t sock, int timeout_ms) {
+    timeval tv;
+    tv.tv_sec = timeout_ms / 1000;
+    tv.tv_usec = (timeout_ms % 1000) * 1000;
+    return setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
+}
+
+ssize_t socket_send_buffers(cutils_socket_t sock,
+                            const cutils_socket_buffer_t* buffers,
+                            size_t num_buffers) {
+    if (num_buffers > SOCKET_SEND_BUFFERS_MAX_BUFFERS) {
+        return -1;
+    }
+
+    iovec iovec_buffers[SOCKET_SEND_BUFFERS_MAX_BUFFERS];
+    for (size_t i = 0; i < num_buffers; ++i) {
+        // It's safe to cast away const here; iovec declares non-const
+        // void* because it's used for both send and receive, but since
+        // we're only sending, the data won't be modified.
+        iovec_buffers[i].iov_base = const_cast<void*>(buffers[i].data);
+        iovec_buffers[i].iov_len = buffers[i].length;
+    }
+
+    return writev(sock, iovec_buffers, num_buffers);
+}