84 lines
2.7 KiB
C++
84 lines
2.7 KiB
C++
/*
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* Copyright (C) 2015 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "diagnose_usb.h"
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#include <errno.h>
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#include <unistd.h>
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#include <string>
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#include <android-base/stringprintf.h>
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#if defined(__linux__)
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#include <grp.h>
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#endif
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static const char kPermissionsHelpUrl[] = "http://developer.android.com/tools/device.html";
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// Returns a message describing any potential problems we find with udev, or nullptr if we can't
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// find plugdev information (i.e. udev is not installed).
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static const char* GetUdevProblem() {
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#if defined(__linux__)
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errno = 0;
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group* plugdev_group = getgrnam("plugdev");
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if (plugdev_group == nullptr) {
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if (errno != 0) {
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perror("failed to read plugdev group info");
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}
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// We can't give any generally useful advice here, just let the caller print the help URL.
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return nullptr;
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}
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// getgroups(2) indicates that the group_member() may not check the egid so we check it
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// additionally just to be sure.
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if (group_member(plugdev_group->gr_gid) || getegid() == plugdev_group->gr_gid) {
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// The user is in plugdev so the problem is likely with the udev rules.
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return "verify udev rules";
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}
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return "udev requires plugdev group membership";
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#else
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return nullptr;
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#endif
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}
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// Short help text must be a single line, and will look something like:
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// no permissions (reason); see <URL>
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std::string UsbNoPermissionsShortHelpText() {
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std::string help_text = "no permissions";
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const char* problem = GetUdevProblem();
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if (problem != nullptr) {
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help_text += android::base::StringPrintf(" (%s)", problem);
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}
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return android::base::StringPrintf("%s; see [%s]", help_text.c_str(), kPermissionsHelpUrl);
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}
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// Long help text can span multiple lines and should provide more detailed information.
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std::string UsbNoPermissionsLongHelpText() {
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std::string header = "insufficient permissions for device";
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const char* problem = GetUdevProblem();
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if (problem != nullptr) {
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header += android::base::StringPrintf(": %s", problem);
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}
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return android::base::StringPrintf("%s.\nSee [%s] for more information.",
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header.c_str(), kPermissionsHelpUrl);
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}
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