Qt/QML edition

mac/macfile.cpp

@@ -0,0 +1,126 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (C) 2020 Raspberry Pi (Trading) Limited
+ */
+
+#include "macfile.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <security/Authorization.h>
+#include <QDebug>
+
+MacFile::MacFile(QObject *parent)
+    : QFile(parent)
+{
+
+}
+
+/* Prevent that Qt thinks /dev/rdisk does not permit seeks because it does not report size */
+bool MacFile::isSequential() const
+{
+    return false;
+}
+
+bool MacFile::authOpen(const QByteArray &filename)
+{
+    int fd = -1;
+
+    QByteArray right = "sys.openfile.readwrite."+filename;
+    AuthorizationItem item = {right, 0, nullptr, 0};
+    AuthorizationRights rights = {1, &item};
+    AuthorizationFlags flags = kAuthorizationFlagInteractionAllowed |
+            kAuthorizationFlagExtendRights |
+            kAuthorizationFlagPreAuthorize;
+    AuthorizationRef authRef;
+    if (AuthorizationCreate(&rights, nullptr, flags, &authRef) != 0)
+        return false;
+
+    AuthorizationExternalForm externalForm;
+    if (AuthorizationMakeExternalForm(authRef, &externalForm) != 0)
+    {
+        AuthorizationFree(authRef, 0);
+        return false;
+    }
+
+    const char *cmd = "/usr/libexec/authopen";
+    QByteArray mode = QByteArray::number(O_RDWR);
+    int pipe[2];
+    int stdinpipe[2];
+    ::socketpair(AF_UNIX, SOCK_STREAM, 0, pipe);
+    ::pipe(stdinpipe);
+    pid_t pid = ::fork();
+    if (pid == 0)
+    {
+        // child
+        ::close(pipe[0]);
+        ::close(stdinpipe[1]);
+        ::dup2(pipe[1], STDOUT_FILENO);
+        ::dup2(stdinpipe[0], STDIN_FILENO);
+        ::execl(cmd, cmd, "-stdoutpipe", "-extauth", "-o", mode.data(), filename.data(), NULL);
+        ::exit(-1);
+    }
+    else
+    {
+        ::close(pipe[1]);
+        ::close(stdinpipe[0]);
+        ::write(stdinpipe[1], externalForm.bytes, sizeof(externalForm.bytes));
+        ::close(stdinpipe[1]);
+
+        const size_t bufSize = CMSG_SPACE(sizeof(int));
+        char buf[bufSize];
+        struct iovec io_vec[1];
+        io_vec[0].iov_base = buf;
+        io_vec[0].iov_len = bufSize;
+        const size_t cmsgSize = CMSG_SPACE(sizeof(int));
+        char cmsg[cmsgSize];
+
+        struct msghdr msg = {0};
+        msg.msg_iov = io_vec;
+        msg.msg_iovlen = 1;
+        msg.msg_control = cmsg;
+        msg.msg_controllen = cmsgSize;
+
+        ssize_t size;
+        do {
+            size = recvmsg(pipe[0], &msg, 0);
+        } while (size == -1 && errno == EINTR);
+
+        qDebug() << "RECEIVED SIZE:" << size;
+
+        if (size > 0) {
+            struct cmsghdr *chdr = CMSG_FIRSTHDR(&msg);
+            if (chdr && chdr->cmsg_type == SCM_RIGHTS) {
+                qDebug() << "SCMRIGHTS";
+                fd = *( (int*) (CMSG_DATA(chdr)) );
+            }
+            else
+            {
+                qDebug() << "NOT SCMRIGHTS";
+            }
+        }
+
+        pid_t wpid;
+        int status;
+
+        do {
+            wpid = ::waitpid(pid, &status, 0);
+        } while (wpid == -1 && errno == EINTR);
+
+        if (wpid == -1)
+        {
+            qDebug() << "waitpid() failed executing authopen";
+            return false;
+        }
+        if (WEXITSTATUS(status))
+        {
+            qDebug() << "authopen returned failure code" << WEXITSTATUS(status);
+            return false;
+        }
+
+        qDebug() << "fd received:" << fd;
+    }
+    AuthorizationFree(authRef, 0);
+
+    return open(fd, QIODevice::ReadWrite | QIODevice::ExistingOnly | QIODevice::Unbuffered, QFileDevice::AutoCloseHandle);
+}

mac/macfile.h

@@ -0,0 +1,20 @@
+#ifndef MACFILE_H
+#define MACFILE_H
+
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (C) 2020 Raspberry Pi (Trading) Limited
+ */
+
+#include <QFile>
+
+class MacFile : public QFile
+{
+    Q_OBJECT
+public:
+    MacFile(QObject *parent = nullptr);
+    virtual bool isSequential() const;
+    bool authOpen(const QByteArray &filename);
+};
+
+#endif // MACFILE_H