Move functions for controlling Caps Lock to CapsLockDelegate from SystemTrayDelegate.
[chromium-blink-merge.git] / base / linux_util.cc
blob49df773ca11a2fd31108c67573ef185644c4f69f
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "base/linux_util.h"
7 #include <dirent.h>
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <stdlib.h>
11 #include <sys/stat.h>
12 #include <sys/types.h>
13 #include <unistd.h>
15 #include <vector>
17 #include "base/command_line.h"
18 #include "base/file_util.h"
19 #include "base/memory/scoped_ptr.h"
20 #include "base/memory/singleton.h"
21 #include "base/path_service.h"
22 #include "base/process_util.h"
23 #include "base/string_util.h"
24 #include "base/synchronization/lock.h"
26 namespace {
28 // Not needed for OS_CHROMEOS.
29 #if defined(OS_LINUX)
30 enum LinuxDistroState {
31 STATE_DID_NOT_CHECK = 0,
32 STATE_CHECK_STARTED = 1,
33 STATE_CHECK_FINISHED = 2,
36 // Helper class for GetLinuxDistro().
37 class LinuxDistroHelper {
38 public:
39 // Retrieves the Singleton.
40 static LinuxDistroHelper* GetInstance() {
41 return Singleton<LinuxDistroHelper>::get();
44 // The simple state machine goes from:
45 // STATE_DID_NOT_CHECK -> STATE_CHECK_STARTED -> STATE_CHECK_FINISHED.
46 LinuxDistroHelper() : state_(STATE_DID_NOT_CHECK) {}
47 ~LinuxDistroHelper() {}
49 // Retrieve the current state, if we're in STATE_DID_NOT_CHECK,
50 // we automatically move to STATE_CHECK_STARTED so nobody else will
51 // do the check.
52 LinuxDistroState State() {
53 base::AutoLock scoped_lock(lock_);
54 if (STATE_DID_NOT_CHECK == state_) {
55 state_ = STATE_CHECK_STARTED;
56 return STATE_DID_NOT_CHECK;
58 return state_;
61 // Indicate the check finished, move to STATE_CHECK_FINISHED.
62 void CheckFinished() {
63 base::AutoLock scoped_lock(lock_);
64 DCHECK_EQ(STATE_CHECK_STARTED, state_);
65 state_ = STATE_CHECK_FINISHED;
68 private:
69 base::Lock lock_;
70 LinuxDistroState state_;
72 #endif // if defined(OS_LINUX)
74 // expected prefix of the target of the /proc/self/fd/%d link for a socket
75 const char kSocketLinkPrefix[] = "socket:[";
77 // Parse a symlink in /proc/pid/fd/$x and return the inode number of the
78 // socket.
79 // inode_out: (output) set to the inode number on success
80 // path: e.g. /proc/1234/fd/5 (must be a UNIX domain socket descriptor)
81 // log: if true, log messages about failure details
82 bool ProcPathGetInode(ino_t* inode_out, const char* path, bool log = false) {
83 DCHECK(inode_out);
84 DCHECK(path);
86 char buf[256];
87 const ssize_t n = readlink(path, buf, sizeof(buf) - 1);
88 if (n == -1) {
89 if (log) {
90 DLOG(WARNING) << "Failed to read the inode number for a socket from /proc"
91 "(" << errno << ")";
93 return false;
95 buf[n] = 0;
97 if (memcmp(kSocketLinkPrefix, buf, sizeof(kSocketLinkPrefix) - 1)) {
98 if (log) {
99 DLOG(WARNING) << "The descriptor passed from the crashing process wasn't "
100 " a UNIX domain socket.";
102 return false;
105 char* endptr;
106 const unsigned long long int inode_ul =
107 strtoull(buf + sizeof(kSocketLinkPrefix) - 1, &endptr, 10);
108 if (*endptr != ']')
109 return false;
111 if (inode_ul == ULLONG_MAX) {
112 if (log) {
113 DLOG(WARNING) << "Failed to parse a socket's inode number: the number "
114 "was too large. Please report this bug: " << buf;
116 return false;
119 *inode_out = inode_ul;
120 return true;
123 } // namespace
125 namespace base {
127 const char kFindInodeSwitch[] = "--find-inode";
129 // Account for the terminating null character.
130 static const int kDistroSize = 128 + 1;
132 // We use this static string to hold the Linux distro info. If we
133 // crash, the crash handler code will send this in the crash dump.
134 char g_linux_distro[kDistroSize] =
135 #if defined(OS_CHROMEOS)
136 "CrOS";
137 #elif defined(OS_ANDROID)
138 "Android";
139 #else // if defined(OS_LINUX)
140 "Unknown";
141 #endif
143 std::string GetLinuxDistro() {
144 #if defined(OS_CHROMEOS) || defined(OS_ANDROID)
145 return g_linux_distro;
146 #elif defined(OS_LINUX)
147 LinuxDistroHelper* distro_state_singleton = LinuxDistroHelper::GetInstance();
148 LinuxDistroState state = distro_state_singleton->State();
149 if (STATE_CHECK_FINISHED == state)
150 return g_linux_distro;
151 if (STATE_CHECK_STARTED == state)
152 return "Unknown"; // Don't wait for other thread to finish.
153 DCHECK_EQ(state, STATE_DID_NOT_CHECK);
154 // We do this check only once per process. If it fails, there's
155 // little reason to believe it will work if we attempt to run
156 // lsb_release again.
157 std::vector<std::string> argv;
158 argv.push_back("lsb_release");
159 argv.push_back("-d");
160 std::string output;
161 base::GetAppOutput(CommandLine(argv), &output);
162 if (output.length() > 0) {
163 // lsb_release -d should return: Description:<tab>Distro Info
164 const char field[] = "Description:\t";
165 if (output.compare(0, strlen(field), field) == 0) {
166 SetLinuxDistro(output.substr(strlen(field)));
169 distro_state_singleton->CheckFinished();
170 return g_linux_distro;
171 #else
172 NOTIMPLEMENTED();
173 return "Unknown";
174 #endif
177 void SetLinuxDistro(const std::string& distro) {
178 std::string trimmed_distro;
179 TrimWhitespaceASCII(distro, TRIM_ALL, &trimmed_distro);
180 base::strlcpy(g_linux_distro, trimmed_distro.c_str(), kDistroSize);
183 bool FileDescriptorGetInode(ino_t* inode_out, int fd) {
184 DCHECK(inode_out);
186 struct stat buf;
187 if (fstat(fd, &buf) < 0)
188 return false;
190 if (!S_ISSOCK(buf.st_mode))
191 return false;
193 *inode_out = buf.st_ino;
194 return true;
197 bool FindProcessHoldingSocket(pid_t* pid_out, ino_t socket_inode) {
198 DCHECK(pid_out);
199 bool already_found = false;
201 DIR* proc = opendir("/proc");
202 if (!proc) {
203 DLOG(WARNING) << "Cannot open /proc";
204 return false;
207 std::vector<pid_t> pids;
209 struct dirent* dent;
210 while ((dent = readdir(proc))) {
211 char* endptr;
212 const unsigned long int pid_ul = strtoul(dent->d_name, &endptr, 10);
213 if (pid_ul == ULONG_MAX || *endptr)
214 continue;
215 pids.push_back(pid_ul);
217 closedir(proc);
219 for (std::vector<pid_t>::const_iterator
220 i = pids.begin(); i != pids.end(); ++i) {
221 const pid_t current_pid = *i;
222 char buf[256];
223 snprintf(buf, sizeof(buf), "/proc/%d/fd", current_pid);
224 DIR* fd = opendir(buf);
225 if (!fd)
226 continue;
228 while ((dent = readdir(fd))) {
229 if (snprintf(buf, sizeof(buf), "/proc/%d/fd/%s", current_pid,
230 dent->d_name) >= static_cast<int>(sizeof(buf))) {
231 continue;
234 ino_t fd_inode;
235 if (ProcPathGetInode(&fd_inode, buf)) {
236 if (fd_inode == socket_inode) {
237 if (already_found) {
238 closedir(fd);
239 return false;
242 already_found = true;
243 *pid_out = current_pid;
244 break;
249 closedir(fd);
252 return already_found;
255 pid_t FindThreadIDWithSyscall(pid_t pid, const std::string& expected_data,
256 bool* syscall_supported) {
257 char buf[256];
258 snprintf(buf, sizeof(buf), "/proc/%d/task", pid);
260 if (syscall_supported != NULL)
261 *syscall_supported = false;
263 DIR* task = opendir(buf);
264 if (!task) {
265 DLOG(WARNING) << "Cannot open " << buf;
266 return -1;
269 std::vector<pid_t> tids;
270 struct dirent* dent;
271 while ((dent = readdir(task))) {
272 char* endptr;
273 const unsigned long int tid_ul = strtoul(dent->d_name, &endptr, 10);
274 if (tid_ul == ULONG_MAX || *endptr)
275 continue;
276 tids.push_back(tid_ul);
278 closedir(task);
280 scoped_array<char> syscall_data(new char[expected_data.length()]);
281 for (std::vector<pid_t>::const_iterator
282 i = tids.begin(); i != tids.end(); ++i) {
283 const pid_t current_tid = *i;
284 snprintf(buf, sizeof(buf), "/proc/%d/task/%d/syscall", pid, current_tid);
285 int fd = open(buf, O_RDONLY);
286 if (fd < 0)
287 continue;
288 if (syscall_supported != NULL)
289 *syscall_supported = true;
290 bool read_ret =
291 file_util::ReadFromFD(fd, syscall_data.get(), expected_data.length());
292 close(fd);
293 if (!read_ret)
294 continue;
296 if (0 == strncmp(expected_data.c_str(), syscall_data.get(),
297 expected_data.length())) {
298 return current_tid;
301 return -1;
304 } // namespace base