105 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			105 lines
		
	
	
		
			3.4 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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| 
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| #include "diagnose_usb.h"
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| 
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| #include <errno.h>
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| #include <unistd.h>
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| 
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| #include <algorithm>
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| #include <string>
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| #include <vector>
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| 
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| #include <android-base/stringprintf.h>
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| 
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| #if defined(__linux__)
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| #include <grp.h>
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| #include <pwd.h>
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| #endif
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| 
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| static const char kPermissionsHelpUrl[] = "http://developer.android.com/tools/device.html";
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| 
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| // Returns a message describing any potential problems we find with udev, or an empty string if we
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| // can't find plugdev information (i.e. udev is not installed).
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| static std::string GetUdevProblem() {
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| #if defined(__linux__) && !defined(__BIONIC__)
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|     errno = 0;
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|     group* plugdev_group = getgrnam("plugdev");
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| 
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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 "";
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|     }
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| 
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|     int ngroups = getgroups(0, nullptr);
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|     if (ngroups < 0) {
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|         perror("failed to get groups list size");
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|         return "";
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|     }
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| 
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|     std::vector<gid_t> groups(ngroups);
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|     ngroups = getgroups(groups.size(), groups.data());
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|     if (ngroups < 0) {
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|         perror("failed to get groups list");
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|         return "";
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|     }
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| 
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|     groups.resize(ngroups);
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| 
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|     // getgroups(2) indicates that the egid may not be included so we check it additionally just
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|     // to be sure.
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|     if (std::find(groups.begin(), groups.end(), plugdev_group->gr_gid) != groups.end() ||
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|         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 "missing udev rules? user is in the plugdev group";
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|     }
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|     passwd* pwd = getpwuid(getuid());
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|     return android::base::StringPrintf("user %s is not in the plugdev group",
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|                                        pwd ? pwd->pw_name : "?");
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| #else
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|     return "";
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| #endif
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| }
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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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| //
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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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| 
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|     std::string problem(GetUdevProblem());
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|     if (!problem.empty()) help_text += " (" + 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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| 
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| // Long help text can span multiple lines but doesn't currently provide more detailed information:
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| //
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| //   insufficient permissions for device: reason
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| //   See [URL] for more information
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| std::string UsbNoPermissionsLongHelpText() {
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|     std::string header = "insufficient permissions for device";
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| 
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|     std::string problem(GetUdevProblem());
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|     if (!problem.empty()) header += ": " + problem;
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| 
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|     return android::base::StringPrintf("%s\nSee [%s] for more information", header.c_str(),
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|                                        kPermissionsHelpUrl);
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| }
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