diff options
Diffstat (limited to 'nix/libutil/util.cc')
| -rw-r--r-- | nix/libutil/util.cc | 216 |
1 files changed, 123 insertions, 93 deletions
diff --git a/nix/libutil/util.cc b/nix/libutil/util.cc index 846674a29d..dab4235b04 100644 --- a/nix/libutil/util.cc +++ b/nix/libutil/util.cc @@ -1,5 +1,8 @@ #include "config.h" +#include "util.hh" +#include "affinity.hh" + #include <iostream> #include <cerrno> #include <cstdio> @@ -16,7 +19,9 @@ #include <sys/syscall.h> #endif -#include "util.hh" +#ifdef __linux__ +#include <sys/prctl.h> +#endif extern char * * environ; @@ -125,7 +130,6 @@ Path canonPath(const Path & path, bool resolveSymlinks) i = temp.begin(); /* restart */ end = temp.end(); s = ""; - /* !!! potential for infinite loop */ } } } @@ -189,8 +193,12 @@ Path readLink(const Path & path) if (!S_ISLNK(st.st_mode)) throw Error(format("`%1%' is not a symlink") % path); char buf[st.st_size]; - if (readlink(path.c_str(), buf, st.st_size) != st.st_size) - throw SysError(format("reading symbolic link `%1%'") % path); + ssize_t rlsize = readlink(path.c_str(), buf, st.st_size); + if (rlsize == -1) + throw SysError(format("reading symbolic link '%1%'") % path); + else if (rlsize > st.st_size) + throw Error(format("symbolic link ‘%1%’ size overflow %2% > %3%") + % path % rlsize % st.st_size); return string(buf, st.st_size); } @@ -202,9 +210,10 @@ bool isLink(const Path & path) } -Strings readDirectory(const Path & path) +DirEntries readDirectory(const Path & path) { - Strings names; + DirEntries entries; + entries.reserve(64); AutoCloseDir dir = opendir(path.c_str()); if (!dir) throw SysError(format("opening directory `%1%'") % path); @@ -214,11 +223,21 @@ Strings readDirectory(const Path & path) checkInterrupt(); string name = dirent->d_name; if (name == "." || name == "..") continue; - names.push_back(name); + entries.emplace_back(name, dirent->d_ino, dirent->d_type); } if (errno) throw SysError(format("reading directory `%1%'") % path); - return names; + return entries; +} + + +unsigned char getFileType(const Path & path) +{ + struct stat st = lstat(path); + if (S_ISDIR(st.st_mode)) return DT_DIR; + if (S_ISLNK(st.st_mode)) return DT_LNK; + if (S_ISREG(st.st_mode)) return DT_REG; + return DT_UNKNOWN; } @@ -249,8 +268,8 @@ void writeFile(const Path & path, const string & s) { AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666); if (fd == -1) - throw SysError(format("opening file `%1%'") % path); - writeFull(fd, (unsigned char *) s.data(), s.size()); + throw SysError(format("opening file '%1%'") % path); + writeFull(fd, s); } @@ -277,7 +296,7 @@ string readLine(int fd) void writeLine(int fd, string s) { s += '\n'; - writeFull(fd, (const unsigned char *) s.data(), s.size()); + writeFull(fd, s); } @@ -293,16 +312,14 @@ static void _deletePath(const Path & path, unsigned long long & bytesFreed) bytesFreed += st.st_blocks * 512; if (S_ISDIR(st.st_mode)) { - Strings names = readDirectory(path); - /* Make the directory writable. */ if (!(st.st_mode & S_IWUSR)) { if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1) throw SysError(format("making `%1%' writable") % path); } - for (Strings::iterator i = names.begin(); i != names.end(); ++i) - _deletePath(path + "/" + *i, bytesFreed); + for (auto & i : readDirectory(path)) + _deletePath(path + "/" + i.name, bytesFreed); } if (remove(path.c_str()) == -1) @@ -380,6 +397,9 @@ Paths createDirs(const Path & path) created.push_back(path); } + if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) + throw SysError(format("statting symlink `%1%'") % path); + if (!S_ISDIR(st.st_mode)) throw Error(format("`%1%' is not a directory") % path); return created; @@ -469,7 +489,10 @@ void warnOnce(bool & haveWarned, const FormatOrString & fs) void writeToStderr(const string & s) { try { - _writeToStderr((const unsigned char *) s.data(), s.size()); + if (_writeToStderr) + _writeToStderr((const unsigned char *) s.data(), s.size()); + else + writeFull(STDERR_FILENO, s); } catch (SysError & e) { /* Ignore failing writes to stderr if we're in an exception handler, otherwise throw an exception. We need to ignore @@ -481,13 +504,7 @@ void writeToStderr(const string & s) } -static void defaultWriteToStderr(const unsigned char * buf, size_t count) -{ - writeFull(STDERR_FILENO, buf, count); -} - - -void (*_writeToStderr) (const unsigned char * buf, size_t count) = defaultWriteToStderr; +void (*_writeToStderr) (const unsigned char * buf, size_t count) = 0; void readFull(int fd, unsigned char * buf, size_t count) @@ -521,6 +538,12 @@ void writeFull(int fd, const unsigned char * buf, size_t count) } +void writeFull(int fd, const string & s) +{ + writeFull(fd, (const unsigned char *) s.data(), s.size()); +} + + string drainFD(int fd) { string result; @@ -707,10 +730,14 @@ void AutoCloseDir::close() Pid::Pid() + : pid(-1), separatePG(false), killSignal(SIGKILL) +{ +} + + +Pid::Pid(pid_t pid) + : pid(pid), separatePG(false), killSignal(SIGKILL) { - pid = -1; - separatePG = false; - killSignal = SIGKILL; } @@ -734,11 +761,12 @@ Pid::operator pid_t() } -void Pid::kill() +void Pid::kill(bool quiet) { if (pid == -1 || pid == 0) return; - printMsg(lvlError, format("killing process %1%") % pid); + if (!quiet) + printMsg(lvlError, format("killing process %1%") % pid); /* Send the requested signal to the child. If it has its own process group, send the signal to every process in the child @@ -801,43 +829,30 @@ void killUser(uid_t uid) users to which the current process can send signals. So we fork a process, switch to uid, and send a mass kill. */ - Pid pid; - pid = fork(); - switch (pid) { - - case -1: - throw SysError("unable to fork"); - - case 0: - try { /* child */ + Pid pid = startProcess([&]() { - if (setuid(uid) == -1) - throw SysError("setting uid"); + if (setuid(uid) == -1) + throw SysError("setting uid"); - while (true) { + while (true) { #ifdef __APPLE__ - /* OSX's kill syscall takes a third parameter that, among other - things, determines if kill(-1, signo) affects the calling - process. In the OSX libc, it's set to true, which means - "follow POSIX", which we don't want here + /* OSX's kill syscall takes a third parameter that, among + other things, determines if kill(-1, signo) affects the + calling process. In the OSX libc, it's set to true, + which means "follow POSIX", which we don't want here */ - if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break; + if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break; #else - if (kill(-1, SIGKILL) == 0) break; + if (kill(-1, SIGKILL) == 0) break; #endif - if (errno == ESRCH) break; /* no more processes */ - if (errno != EINTR) - throw SysError(format("cannot kill processes for uid `%1%'") % uid); - } - - } catch (std::exception & e) { - writeToStderr((format("killing processes belonging to uid `%1%': %2%\n") % uid % e.what()).str()); - _exit(1); + if (errno == ESRCH) break; /* no more processes */ + if (errno != EINTR) + throw SysError(format("cannot kill processes for uid `%1%'") % uid); } + _exit(0); - } + }); - /* parent */ int status = pid.wait(true); if (status != 0) throw Error(format("cannot kill processes for uid `%1%': %2%") % uid % statusToString(status)); @@ -852,47 +867,69 @@ void killUser(uid_t uid) ////////////////////////////////////////////////////////////////////// +pid_t startProcess(std::function<void()> fun, + bool dieWithParent, const string & errorPrefix, bool runExitHandlers) +{ + pid_t pid = fork(); + if (pid == -1) throw SysError("unable to fork"); + + if (pid == 0) { + _writeToStderr = 0; + try { +#if __linux__ + if (dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1) + throw SysError("setting death signal"); +#endif + restoreAffinity(); + fun(); + } catch (std::exception & e) { + try { + std::cerr << errorPrefix << e.what() << "\n"; + } catch (...) { } + } catch (...) { } + if (runExitHandlers) + exit(1); + else + _exit(1); + } + + return pid; +} + + +std::vector<const char *> stringsToCharPtrs(const Strings & ss) +{ + std::vector<const char *> res; + for (auto & s : ss) res.push_back(s.c_str()); + res.push_back(0); + return res; +} + + string runProgram(Path program, bool searchPath, const Strings & args) { checkInterrupt(); - std::vector<const char *> cargs; /* careful with c_str()! */ - cargs.push_back(program.c_str()); - for (Strings::const_iterator i = args.begin(); i != args.end(); ++i) - cargs.push_back(i->c_str()); - cargs.push_back(0); - /* Create a pipe. */ Pipe pipe; pipe.create(); /* Fork. */ - Pid pid; - pid = maybeVfork(); - - switch (pid) { - - case -1: - throw SysError("unable to fork"); - - case 0: /* child */ - try { - if (dup2(pipe.writeSide, STDOUT_FILENO) == -1) - throw SysError("dupping stdout"); + Pid pid = startProcess([&]() { + if (dup2(pipe.writeSide, STDOUT_FILENO) == -1) + throw SysError("dupping stdout"); - if (searchPath) - execvp(program.c_str(), (char * *) &cargs[0]); - else - execv(program.c_str(), (char * *) &cargs[0]); - throw SysError(format("executing `%1%'") % program); + Strings args_(args); + args_.push_front(program); + auto cargs = stringsToCharPtrs(args_); - } catch (std::exception & e) { - writeToStderr("error: " + string(e.what()) + "\n"); - } - _exit(1); - } + if (searchPath) + execvp(program.c_str(), (char * *) &cargs[0]); + else + execv(program.c_str(), (char * *) &cargs[0]); - /* Parent. */ + throw SysError(format("executing `%1%'") % program); + }); pipe.writeSide.close(); @@ -901,7 +938,7 @@ string runProgram(Path program, bool searchPath, const Strings & args) /* Wait for the child to finish. */ int status = pid.wait(true); if (!statusOk(status)) - throw Error(format("program `%1%' %2%") + throw ExecError(format("program `%1%' %2%") % program % statusToString(status)); return result; @@ -928,13 +965,6 @@ void closeOnExec(int fd) } -#if HAVE_VFORK -pid_t (*maybeVfork)() = vfork; -#else -pid_t (*maybeVfork)() = fork; -#endif - - ////////////////////////////////////////////////////////////////////// |