forked from lix-project/lix
Robert Hensing
c156155239
This solves the error
error: cannot connect to socket at '/nix/var/nix/daemon-socket/socket': Connection refused
on build farm systems that are loaded but operating normally.
I've seen this happen on an M1 mac running a loaded hercules-ci-agent.
Hercules CI uses multiple worker processes, which may connect to
the Nix daemon around the same time. It's not unthinkable that
the Nix daemon listening process isn't scheduled until after 6
workers try to connect, especially on a system under load with
many workers.
Is the increase safe?
The number is the number of connections that the kernel will buffer
while the listening process hasn't `accept`-ed them yet.
It did not - and will not - restrict the total number of daemon
forks that a client can create.
History
The number 5 has remained unchanged since the introduction in
nix-worker with 0130ef88ea in 2006.
1927 lines
48 KiB
C++
1927 lines
48 KiB
C++
#include "util.hh"
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#include "sync.hh"
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#include "finally.hh"
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#include "serialise.hh"
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#include <array>
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#include <cctype>
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#include <cerrno>
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#include <climits>
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#include <cstdio>
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#include <cstdlib>
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#include <cstring>
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#include <future>
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#include <iostream>
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#include <mutex>
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#include <sstream>
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#include <thread>
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#include <fcntl.h>
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#include <grp.h>
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#include <pwd.h>
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#include <sys/ioctl.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/wait.h>
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#include <sys/time.h>
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#include <sys/un.h>
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#include <unistd.h>
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#ifdef __APPLE__
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#include <sys/syscall.h>
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#endif
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#ifdef __linux__
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#include <sys/prctl.h>
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#include <sys/resource.h>
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#endif
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extern char * * environ __attribute__((weak));
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namespace nix {
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std::optional<std::string> getEnv(const std::string & key)
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{
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char * value = getenv(key.c_str());
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if (!value) return {};
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return std::string(value);
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}
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std::map<std::string, std::string> getEnv()
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{
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std::map<std::string, std::string> env;
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for (size_t i = 0; environ[i]; ++i) {
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auto s = environ[i];
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auto eq = strchr(s, '=');
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if (!eq)
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// invalid env, just keep going
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continue;
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env.emplace(std::string(s, eq), std::string(eq + 1));
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}
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return env;
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}
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void clearEnv()
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{
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for (auto & name : getEnv())
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unsetenv(name.first.c_str());
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}
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void replaceEnv(const std::map<std::string, std::string> & newEnv)
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{
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clearEnv();
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for (auto & newEnvVar : newEnv)
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setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1);
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}
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Path absPath(Path path, std::optional<PathView> dir, bool resolveSymlinks)
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{
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if (path[0] != '/') {
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if (!dir) {
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#ifdef __GNU__
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/* GNU (aka. GNU/Hurd) doesn't have any limitation on path
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lengths and doesn't define `PATH_MAX'. */
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char *buf = getcwd(NULL, 0);
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if (buf == NULL)
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#else
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char buf[PATH_MAX];
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if (!getcwd(buf, sizeof(buf)))
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#endif
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throw SysError("cannot get cwd");
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path = concatStrings(buf, "/", path);
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#ifdef __GNU__
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free(buf);
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#endif
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} else
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path = concatStrings(*dir, "/", path);
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}
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return canonPath(path, resolveSymlinks);
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}
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Path canonPath(PathView path, bool resolveSymlinks)
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{
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assert(path != "");
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std::string s;
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s.reserve(256);
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if (path[0] != '/')
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throw Error("not an absolute path: '%1%'", path);
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std::string temp;
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/* Count the number of times we follow a symlink and stop at some
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arbitrary (but high) limit to prevent infinite loops. */
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unsigned int followCount = 0, maxFollow = 1024;
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while (1) {
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/* Skip slashes. */
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while (!path.empty() && path[0] == '/') path.remove_prefix(1);
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if (path.empty()) break;
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/* Ignore `.'. */
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if (path == "." || path.substr(0, 2) == "./")
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path.remove_prefix(1);
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/* If `..', delete the last component. */
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else if (path == ".." || path.substr(0, 3) == "../")
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{
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if (!s.empty()) s.erase(s.rfind('/'));
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path.remove_prefix(2);
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}
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/* Normal component; copy it. */
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else {
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s += '/';
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if (const auto slash = path.find('/'); slash == std::string::npos) {
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s += path;
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path = {};
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} else {
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s += path.substr(0, slash);
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path = path.substr(slash);
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}
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/* If s points to a symlink, resolve it and continue from there */
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if (resolveSymlinks && isLink(s)) {
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if (++followCount >= maxFollow)
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throw Error("infinite symlink recursion in path '%1%'", path);
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temp = concatStrings(readLink(s), path);
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path = temp;
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if (!temp.empty() && temp[0] == '/') {
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s.clear(); /* restart for symlinks pointing to absolute path */
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} else {
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s = dirOf(s);
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if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = /
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s.clear();
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}
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}
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}
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}
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}
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return s.empty() ? "/" : std::move(s);
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}
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Path dirOf(const PathView path)
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{
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Path::size_type pos = path.rfind('/');
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if (pos == std::string::npos)
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return ".";
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return pos == 0 ? "/" : Path(path, 0, pos);
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}
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std::string_view baseNameOf(std::string_view path)
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{
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if (path.empty())
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return "";
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auto last = path.size() - 1;
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if (path[last] == '/' && last > 0)
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last -= 1;
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auto pos = path.rfind('/', last);
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if (pos == std::string::npos)
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pos = 0;
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else
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pos += 1;
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return path.substr(pos, last - pos + 1);
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}
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std::string expandTilde(std::string_view path)
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{
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// TODO: expand ~user ?
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auto tilde = path.substr(0, 2);
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if (tilde == "~/" || tilde == "~")
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return getHome() + std::string(path.substr(1));
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else
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return std::string(path);
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}
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bool isInDir(std::string_view path, std::string_view dir)
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{
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return path.substr(0, 1) == "/"
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&& path.substr(0, dir.size()) == dir
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&& path.size() >= dir.size() + 2
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&& path[dir.size()] == '/';
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}
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bool isDirOrInDir(std::string_view path, std::string_view dir)
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{
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return path == dir || isInDir(path, dir);
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}
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struct stat stat(const Path & path)
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{
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struct stat st;
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if (stat(path.c_str(), &st))
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throw SysError("getting status of '%1%'", path);
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return st;
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}
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struct stat lstat(const Path & path)
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{
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struct stat st;
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if (lstat(path.c_str(), &st))
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throw SysError("getting status of '%1%'", path);
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return st;
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}
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bool pathExists(const Path & path)
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{
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int res;
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struct stat st;
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res = lstat(path.c_str(), &st);
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if (!res) return true;
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if (errno != ENOENT && errno != ENOTDIR)
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throw SysError("getting status of %1%", path);
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return false;
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}
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Path readLink(const Path & path)
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{
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checkInterrupt();
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std::vector<char> buf;
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for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) {
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buf.resize(bufSize);
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ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize);
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if (rlSize == -1)
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if (errno == EINVAL)
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throw Error("'%1%' is not a symlink", path);
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else
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throw SysError("reading symbolic link '%1%'", path);
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else if (rlSize < bufSize)
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return std::string(buf.data(), rlSize);
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}
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}
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bool isLink(const Path & path)
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{
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struct stat st = lstat(path);
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return S_ISLNK(st.st_mode);
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}
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DirEntries readDirectory(DIR *dir, const Path & path)
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{
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DirEntries entries;
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entries.reserve(64);
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struct dirent * dirent;
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while (errno = 0, dirent = readdir(dir)) { /* sic */
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checkInterrupt();
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std::string name = dirent->d_name;
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if (name == "." || name == "..") continue;
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entries.emplace_back(name, dirent->d_ino,
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#ifdef HAVE_STRUCT_DIRENT_D_TYPE
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dirent->d_type
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#else
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DT_UNKNOWN
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#endif
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);
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}
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if (errno) throw SysError("reading directory '%1%'", path);
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return entries;
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}
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DirEntries readDirectory(const Path & path)
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{
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AutoCloseDir dir(opendir(path.c_str()));
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if (!dir) throw SysError("opening directory '%1%'", path);
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return readDirectory(dir.get(), path);
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}
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unsigned char getFileType(const Path & path)
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{
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struct stat st = lstat(path);
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if (S_ISDIR(st.st_mode)) return DT_DIR;
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if (S_ISLNK(st.st_mode)) return DT_LNK;
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if (S_ISREG(st.st_mode)) return DT_REG;
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return DT_UNKNOWN;
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}
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std::string readFile(int fd)
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{
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struct stat st;
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if (fstat(fd, &st) == -1)
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throw SysError("statting file");
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return drainFD(fd, true, st.st_size);
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}
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std::string readFile(const Path & path)
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{
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AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_CLOEXEC);
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if (!fd)
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throw SysError("opening file '%1%'", path);
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return readFile(fd.get());
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}
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void readFile(const Path & path, Sink & sink)
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{
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AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_CLOEXEC);
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if (!fd)
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throw SysError("opening file '%s'", path);
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drainFD(fd.get(), sink);
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}
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void writeFile(const Path & path, std::string_view s, mode_t mode)
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{
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AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode);
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if (!fd)
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throw SysError("opening file '%1%'", path);
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try {
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writeFull(fd.get(), s);
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} catch (Error & e) {
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e.addTrace({}, "writing file '%1%'", path);
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throw;
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}
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}
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void writeFile(const Path & path, Source & source, mode_t mode)
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{
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AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode);
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if (!fd)
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throw SysError("opening file '%1%'", path);
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std::vector<char> buf(64 * 1024);
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try {
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while (true) {
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try {
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auto n = source.read(buf.data(), buf.size());
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writeFull(fd.get(), {buf.data(), n});
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} catch (EndOfFile &) { break; }
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}
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} catch (Error & e) {
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e.addTrace({}, "writing file '%1%'", path);
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throw;
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}
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}
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std::string readLine(int fd)
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{
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std::string s;
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while (1) {
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checkInterrupt();
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char ch;
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// FIXME: inefficient
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ssize_t rd = read(fd, &ch, 1);
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if (rd == -1) {
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if (errno != EINTR)
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throw SysError("reading a line");
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} else if (rd == 0)
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throw EndOfFile("unexpected EOF reading a line");
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else {
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if (ch == '\n') return s;
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s += ch;
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}
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}
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}
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void writeLine(int fd, std::string s)
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{
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s += '\n';
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writeFull(fd, s);
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}
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static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed)
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{
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checkInterrupt();
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std::string name(baseNameOf(path));
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struct stat st;
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if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) {
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if (errno == ENOENT) return;
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throw SysError("getting status of '%1%'", path);
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}
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if (!S_ISDIR(st.st_mode)) {
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/* We are about to delete a file. Will it likely free space? */
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switch (st.st_nlink) {
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/* Yes: last link. */
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case 1:
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bytesFreed += st.st_size;
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break;
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/* Maybe: yes, if 'auto-optimise-store' or manual optimisation
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was performed. Instead of checking for real let's assume
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it's an optimised file and space will be freed.
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In worst case we will double count on freed space for files
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with exactly two hardlinks for unoptimised packages.
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*/
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case 2:
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bytesFreed += st.st_size;
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break;
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/* No: 3+ links. */
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default:
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break;
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}
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}
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if (S_ISDIR(st.st_mode)) {
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/* Make the directory accessible. */
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const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR;
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if ((st.st_mode & PERM_MASK) != PERM_MASK) {
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if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1)
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throw SysError("chmod '%1%'", path);
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}
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int fd = openat(parentfd, path.c_str(), O_RDONLY);
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if (fd == -1)
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throw SysError("opening directory '%1%'", path);
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AutoCloseDir dir(fdopendir(fd));
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if (!dir)
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throw SysError("opening directory '%1%'", path);
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for (auto & i : readDirectory(dir.get(), path))
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_deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed);
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}
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int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0;
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if (unlinkat(parentfd, name.c_str(), flags) == -1) {
|
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if (errno == ENOENT) return;
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throw SysError("cannot unlink '%1%'", path);
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}
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}
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static void _deletePath(const Path & path, uint64_t & bytesFreed)
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{
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Path dir = dirOf(path);
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if (dir == "")
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dir = "/";
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AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)};
|
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if (!dirfd) {
|
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if (errno == ENOENT) return;
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throw SysError("opening directory '%1%'", path);
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}
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_deletePath(dirfd.get(), path, bytesFreed);
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}
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void deletePath(const Path & path)
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{
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uint64_t dummy;
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deletePath(path, dummy);
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}
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void deletePath(const Path & path, uint64_t & bytesFreed)
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{
|
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//Activity act(*logger, lvlDebug, format("recursively deleting path '%1%'") % path);
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bytesFreed = 0;
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_deletePath(path, bytesFreed);
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}
|
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|
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static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
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int & counter)
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{
|
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tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true);
|
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if (includePid)
|
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return (format("%1%/%2%-%3%-%4%") % tmpRoot % prefix % getpid() % counter++).str();
|
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else
|
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return (format("%1%/%2%-%3%") % tmpRoot % prefix % counter++).str();
|
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}
|
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|
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|
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Path createTempDir(const Path & tmpRoot, const Path & prefix,
|
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bool includePid, bool useGlobalCounter, mode_t mode)
|
||
{
|
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static int globalCounter = 0;
|
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int localCounter = 0;
|
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int & counter(useGlobalCounter ? globalCounter : localCounter);
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|
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while (1) {
|
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checkInterrupt();
|
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Path tmpDir = tempName(tmpRoot, prefix, includePid, counter);
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if (mkdir(tmpDir.c_str(), mode) == 0) {
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#if __FreeBSD__
|
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/* Explicitly set the group of the directory. This is to
|
||
work around around problems caused by BSD's group
|
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ownership semantics (directories inherit the group of
|
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the parent). For instance, the group of /tmp on
|
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FreeBSD is "wheel", so all directories created in /tmp
|
||
will be owned by "wheel"; but if the user is not in
|
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"wheel", then "tar" will fail to unpack archives that
|
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have the setgid bit set on directories. */
|
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if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0)
|
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throw SysError("setting group of directory '%1%'", tmpDir);
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#endif
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return tmpDir;
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||
}
|
||
if (errno != EEXIST)
|
||
throw SysError("creating directory '%1%'", tmpDir);
|
||
}
|
||
}
|
||
|
||
|
||
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix)
|
||
{
|
||
Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX");
|
||
// Strictly speaking, this is UB, but who cares...
|
||
// FIXME: use O_TMPFILE.
|
||
AutoCloseFD fd(mkstemp((char *) tmpl.c_str()));
|
||
if (!fd)
|
||
throw SysError("creating temporary file '%s'", tmpl);
|
||
closeOnExec(fd.get());
|
||
return {std::move(fd), tmpl};
|
||
}
|
||
|
||
|
||
std::string getUserName()
|
||
{
|
||
auto pw = getpwuid(geteuid());
|
||
std::string name = pw ? pw->pw_name : getEnv("USER").value_or("");
|
||
if (name.empty())
|
||
throw Error("cannot figure out user name");
|
||
return name;
|
||
}
|
||
|
||
|
||
Path getHome()
|
||
{
|
||
static Path homeDir = []()
|
||
{
|
||
auto homeDir = getEnv("HOME");
|
||
if (!homeDir) {
|
||
std::vector<char> buf(16384);
|
||
struct passwd pwbuf;
|
||
struct passwd * pw;
|
||
if (getpwuid_r(geteuid(), &pwbuf, buf.data(), buf.size(), &pw) != 0
|
||
|| !pw || !pw->pw_dir || !pw->pw_dir[0])
|
||
throw Error("cannot determine user's home directory");
|
||
homeDir = pw->pw_dir;
|
||
}
|
||
return *homeDir;
|
||
}();
|
||
return homeDir;
|
||
}
|
||
|
||
|
||
Path getCacheDir()
|
||
{
|
||
auto cacheDir = getEnv("XDG_CACHE_HOME");
|
||
return cacheDir ? *cacheDir : getHome() + "/.cache";
|
||
}
|
||
|
||
|
||
Path getConfigDir()
|
||
{
|
||
auto configDir = getEnv("XDG_CONFIG_HOME");
|
||
return configDir ? *configDir : getHome() + "/.config";
|
||
}
|
||
|
||
std::vector<Path> getConfigDirs()
|
||
{
|
||
Path configHome = getConfigDir();
|
||
auto configDirs = getEnv("XDG_CONFIG_DIRS").value_or("/etc/xdg");
|
||
std::vector<Path> result = tokenizeString<std::vector<std::string>>(configDirs, ":");
|
||
result.insert(result.begin(), configHome);
|
||
return result;
|
||
}
|
||
|
||
|
||
Path getDataDir()
|
||
{
|
||
auto dataDir = getEnv("XDG_DATA_HOME");
|
||
return dataDir ? *dataDir : getHome() + "/.local/share";
|
||
}
|
||
|
||
|
||
Paths createDirs(const Path & path)
|
||
{
|
||
Paths created;
|
||
if (path == "/") return created;
|
||
|
||
struct stat st;
|
||
if (lstat(path.c_str(), &st) == -1) {
|
||
created = createDirs(dirOf(path));
|
||
if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST)
|
||
throw SysError("creating directory '%1%'", path);
|
||
st = lstat(path);
|
||
created.push_back(path);
|
||
}
|
||
|
||
if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1)
|
||
throw SysError("statting symlink '%1%'", path);
|
||
|
||
if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path);
|
||
|
||
return created;
|
||
}
|
||
|
||
|
||
void createSymlink(const Path & target, const Path & link,
|
||
std::optional<time_t> mtime)
|
||
{
|
||
if (symlink(target.c_str(), link.c_str()))
|
||
throw SysError("creating symlink from '%1%' to '%2%'", link, target);
|
||
if (mtime) {
|
||
struct timeval times[2];
|
||
times[0].tv_sec = *mtime;
|
||
times[0].tv_usec = 0;
|
||
times[1].tv_sec = *mtime;
|
||
times[1].tv_usec = 0;
|
||
if (lutimes(link.c_str(), times))
|
||
throw SysError("setting time of symlink '%s'", link);
|
||
}
|
||
}
|
||
|
||
|
||
void replaceSymlink(const Path & target, const Path & link,
|
||
std::optional<time_t> mtime)
|
||
{
|
||
for (unsigned int n = 0; true; n++) {
|
||
Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
|
||
|
||
try {
|
||
createSymlink(target, tmp, mtime);
|
||
} catch (SysError & e) {
|
||
if (e.errNo == EEXIST) continue;
|
||
throw;
|
||
}
|
||
|
||
if (rename(tmp.c_str(), link.c_str()) != 0)
|
||
throw SysError("renaming '%1%' to '%2%'", tmp, link);
|
||
|
||
break;
|
||
}
|
||
}
|
||
|
||
|
||
void readFull(int fd, char * buf, size_t count)
|
||
{
|
||
while (count) {
|
||
checkInterrupt();
|
||
ssize_t res = read(fd, buf, count);
|
||
if (res == -1) {
|
||
if (errno == EINTR) continue;
|
||
throw SysError("reading from file");
|
||
}
|
||
if (res == 0) throw EndOfFile("unexpected end-of-file");
|
||
count -= res;
|
||
buf += res;
|
||
}
|
||
}
|
||
|
||
|
||
void writeFull(int fd, std::string_view s, bool allowInterrupts)
|
||
{
|
||
while (!s.empty()) {
|
||
if (allowInterrupts) checkInterrupt();
|
||
ssize_t res = write(fd, s.data(), s.size());
|
||
if (res == -1 && errno != EINTR)
|
||
throw SysError("writing to file");
|
||
if (res > 0)
|
||
s.remove_prefix(res);
|
||
}
|
||
}
|
||
|
||
|
||
std::string drainFD(int fd, bool block, const size_t reserveSize)
|
||
{
|
||
// the parser needs two extra bytes to append terminating characters, other users will
|
||
// not care very much about the extra memory.
|
||
StringSink sink(reserveSize + 2);
|
||
drainFD(fd, sink, block);
|
||
return std::move(sink.s);
|
||
}
|
||
|
||
|
||
void drainFD(int fd, Sink & sink, bool block)
|
||
{
|
||
// silence GCC maybe-uninitialized warning in finally
|
||
int saved = 0;
|
||
|
||
if (!block) {
|
||
saved = fcntl(fd, F_GETFL);
|
||
if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1)
|
||
throw SysError("making file descriptor non-blocking");
|
||
}
|
||
|
||
Finally finally([&]() {
|
||
if (!block) {
|
||
if (fcntl(fd, F_SETFL, saved) == -1)
|
||
throw SysError("making file descriptor blocking");
|
||
}
|
||
});
|
||
|
||
std::vector<unsigned char> buf(64 * 1024);
|
||
while (1) {
|
||
checkInterrupt();
|
||
ssize_t rd = read(fd, buf.data(), buf.size());
|
||
if (rd == -1) {
|
||
if (!block && (errno == EAGAIN || errno == EWOULDBLOCK))
|
||
break;
|
||
if (errno != EINTR)
|
||
throw SysError("reading from file");
|
||
}
|
||
else if (rd == 0) break;
|
||
else sink({(char *) buf.data(), (size_t) rd});
|
||
}
|
||
}
|
||
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
AutoDelete::AutoDelete() : del{false} {}
|
||
|
||
AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p)
|
||
{
|
||
del = true;
|
||
this->recursive = recursive;
|
||
}
|
||
|
||
AutoDelete::~AutoDelete()
|
||
{
|
||
try {
|
||
if (del) {
|
||
if (recursive)
|
||
deletePath(path);
|
||
else {
|
||
if (remove(path.c_str()) == -1)
|
||
throw SysError("cannot unlink '%1%'", path);
|
||
}
|
||
}
|
||
} catch (...) {
|
||
ignoreException();
|
||
}
|
||
}
|
||
|
||
void AutoDelete::cancel()
|
||
{
|
||
del = false;
|
||
}
|
||
|
||
void AutoDelete::reset(const Path & p, bool recursive) {
|
||
path = p;
|
||
this->recursive = recursive;
|
||
del = true;
|
||
}
|
||
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
AutoCloseFD::AutoCloseFD() : fd{-1} {}
|
||
|
||
|
||
AutoCloseFD::AutoCloseFD(int fd) : fd{fd} {}
|
||
|
||
|
||
AutoCloseFD::AutoCloseFD(AutoCloseFD && that) : fd{that.fd}
|
||
{
|
||
that.fd = -1;
|
||
}
|
||
|
||
|
||
AutoCloseFD & AutoCloseFD::operator =(AutoCloseFD && that)
|
||
{
|
||
close();
|
||
fd = that.fd;
|
||
that.fd = -1;
|
||
return *this;
|
||
}
|
||
|
||
|
||
AutoCloseFD::~AutoCloseFD()
|
||
{
|
||
try {
|
||
close();
|
||
} catch (...) {
|
||
ignoreException();
|
||
}
|
||
}
|
||
|
||
|
||
int AutoCloseFD::get() const
|
||
{
|
||
return fd;
|
||
}
|
||
|
||
|
||
void AutoCloseFD::close()
|
||
{
|
||
if (fd != -1) {
|
||
if (::close(fd) == -1)
|
||
/* This should never happen. */
|
||
throw SysError("closing file descriptor %1%", fd);
|
||
fd = -1;
|
||
}
|
||
}
|
||
|
||
|
||
AutoCloseFD::operator bool() const
|
||
{
|
||
return fd != -1;
|
||
}
|
||
|
||
|
||
int AutoCloseFD::release()
|
||
{
|
||
int oldFD = fd;
|
||
fd = -1;
|
||
return oldFD;
|
||
}
|
||
|
||
|
||
void Pipe::create()
|
||
{
|
||
int fds[2];
|
||
#if HAVE_PIPE2
|
||
if (pipe2(fds, O_CLOEXEC) != 0) throw SysError("creating pipe");
|
||
#else
|
||
if (pipe(fds) != 0) throw SysError("creating pipe");
|
||
closeOnExec(fds[0]);
|
||
closeOnExec(fds[1]);
|
||
#endif
|
||
readSide = fds[0];
|
||
writeSide = fds[1];
|
||
}
|
||
|
||
|
||
void Pipe::close()
|
||
{
|
||
readSide.close();
|
||
writeSide.close();
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
Pid::Pid()
|
||
{
|
||
}
|
||
|
||
|
||
Pid::Pid(pid_t pid)
|
||
: pid(pid)
|
||
{
|
||
}
|
||
|
||
|
||
Pid::~Pid()
|
||
{
|
||
if (pid != -1) kill();
|
||
}
|
||
|
||
|
||
void Pid::operator =(pid_t pid)
|
||
{
|
||
if (this->pid != -1 && this->pid != pid) kill();
|
||
this->pid = pid;
|
||
killSignal = SIGKILL; // reset signal to default
|
||
}
|
||
|
||
|
||
Pid::operator pid_t()
|
||
{
|
||
return pid;
|
||
}
|
||
|
||
|
||
int Pid::kill()
|
||
{
|
||
assert(pid != -1);
|
||
|
||
debug("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
|
||
process group (which hopefully includes *all* its children). */
|
||
if (::kill(separatePG ? -pid : pid, killSignal) != 0) {
|
||
/* On BSDs, killing a process group will return EPERM if all
|
||
processes in the group are zombies (or something like
|
||
that). So try to detect and ignore that situation. */
|
||
#if __FreeBSD__ || __APPLE__
|
||
if (errno != EPERM || ::kill(pid, 0) != 0)
|
||
#endif
|
||
logError(SysError("killing process %d", pid).info());
|
||
}
|
||
|
||
return wait();
|
||
}
|
||
|
||
|
||
int Pid::wait()
|
||
{
|
||
assert(pid != -1);
|
||
while (1) {
|
||
int status;
|
||
int res = waitpid(pid, &status, 0);
|
||
if (res == pid) {
|
||
pid = -1;
|
||
return status;
|
||
}
|
||
if (errno != EINTR)
|
||
throw SysError("cannot get exit status of PID %d", pid);
|
||
checkInterrupt();
|
||
}
|
||
}
|
||
|
||
|
||
void Pid::setSeparatePG(bool separatePG)
|
||
{
|
||
this->separatePG = separatePG;
|
||
}
|
||
|
||
|
||
void Pid::setKillSignal(int signal)
|
||
{
|
||
this->killSignal = signal;
|
||
}
|
||
|
||
|
||
pid_t Pid::release()
|
||
{
|
||
pid_t p = pid;
|
||
pid = -1;
|
||
return p;
|
||
}
|
||
|
||
|
||
void killUser(uid_t uid)
|
||
{
|
||
debug("killing all processes running under uid '%1%'", uid);
|
||
|
||
assert(uid != 0); /* just to be safe... */
|
||
|
||
/* The system call kill(-1, sig) sends the signal `sig' to all
|
||
users to which the current process can send signals. So we
|
||
fork a process, switch to uid, and send a mass kill. */
|
||
|
||
Pid pid = startProcess([&]() {
|
||
|
||
if (setuid(uid) == -1)
|
||
throw SysError("setting uid");
|
||
|
||
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
|
||
*/
|
||
if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break;
|
||
#else
|
||
if (kill(-1, SIGKILL) == 0) break;
|
||
#endif
|
||
if (errno == ESRCH || errno == EPERM) break; /* no more processes */
|
||
if (errno != EINTR)
|
||
throw SysError("cannot kill processes for uid '%1%'", uid);
|
||
}
|
||
|
||
_exit(0);
|
||
});
|
||
|
||
int status = pid.wait();
|
||
if (status != 0)
|
||
throw Error("cannot kill processes for uid '%1%': %2%", uid, statusToString(status));
|
||
|
||
/* !!! We should really do some check to make sure that there are
|
||
no processes left running under `uid', but there is no portable
|
||
way to do so (I think). The most reliable way may be `ps -eo
|
||
uid | grep -q $uid'. */
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
/* Wrapper around vfork to prevent the child process from clobbering
|
||
the caller's stack frame in the parent. */
|
||
static pid_t doFork(bool allowVfork, std::function<void()> fun) __attribute__((noinline));
|
||
static pid_t doFork(bool allowVfork, std::function<void()> fun)
|
||
{
|
||
#ifdef __linux__
|
||
pid_t pid = allowVfork ? vfork() : fork();
|
||
#else
|
||
pid_t pid = fork();
|
||
#endif
|
||
if (pid != 0) return pid;
|
||
fun();
|
||
abort();
|
||
}
|
||
|
||
|
||
pid_t startProcess(std::function<void()> fun, const ProcessOptions & options)
|
||
{
|
||
auto wrapper = [&]() {
|
||
if (!options.allowVfork)
|
||
logger = makeSimpleLogger();
|
||
try {
|
||
#if __linux__
|
||
if (options.dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1)
|
||
throw SysError("setting death signal");
|
||
#endif
|
||
fun();
|
||
} catch (std::exception & e) {
|
||
try {
|
||
std::cerr << options.errorPrefix << e.what() << "\n";
|
||
} catch (...) { }
|
||
} catch (...) { }
|
||
if (options.runExitHandlers)
|
||
exit(1);
|
||
else
|
||
_exit(1);
|
||
};
|
||
|
||
pid_t pid = doFork(options.allowVfork, wrapper);
|
||
if (pid == -1) throw SysError("unable to fork");
|
||
|
||
return pid;
|
||
}
|
||
|
||
|
||
std::vector<char *> stringsToCharPtrs(const Strings & ss)
|
||
{
|
||
std::vector<char *> res;
|
||
for (auto & s : ss) res.push_back((char *) s.c_str());
|
||
res.push_back(0);
|
||
return res;
|
||
}
|
||
|
||
std::string runProgram(Path program, bool searchPath, const Strings & args,
|
||
const std::optional<std::string> & input)
|
||
{
|
||
auto res = runProgram(RunOptions {.program = program, .searchPath = searchPath, .args = args, .input = input});
|
||
|
||
if (!statusOk(res.first))
|
||
throw ExecError(res.first, "program '%1%' %2%", program, statusToString(res.first));
|
||
|
||
return res.second;
|
||
}
|
||
|
||
// Output = error code + "standard out" output stream
|
||
std::pair<int, std::string> runProgram(RunOptions && options)
|
||
{
|
||
StringSink sink;
|
||
options.standardOut = &sink;
|
||
|
||
int status = 0;
|
||
|
||
try {
|
||
runProgram2(options);
|
||
} catch (ExecError & e) {
|
||
status = e.status;
|
||
}
|
||
|
||
return {status, std::move(sink.s)};
|
||
}
|
||
|
||
void runProgram2(const RunOptions & options)
|
||
{
|
||
checkInterrupt();
|
||
|
||
assert(!(options.standardIn && options.input));
|
||
|
||
std::unique_ptr<Source> source_;
|
||
Source * source = options.standardIn;
|
||
|
||
if (options.input) {
|
||
source_ = std::make_unique<StringSource>(*options.input);
|
||
source = source_.get();
|
||
}
|
||
|
||
/* Create a pipe. */
|
||
Pipe out, in;
|
||
if (options.standardOut) out.create();
|
||
if (source) in.create();
|
||
|
||
ProcessOptions processOptions;
|
||
// vfork implies that the environment of the main process and the fork will
|
||
// be shared (technically this is undefined, but in practice that's the
|
||
// case), so we can't use it if we alter the environment
|
||
processOptions.allowVfork = !options.environment;
|
||
|
||
/* Fork. */
|
||
Pid pid = startProcess([&]() {
|
||
if (options.environment)
|
||
replaceEnv(*options.environment);
|
||
if (options.standardOut && dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
|
||
throw SysError("dupping stdout");
|
||
if (options.mergeStderrToStdout)
|
||
if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
|
||
throw SysError("cannot dup stdout into stderr");
|
||
if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1)
|
||
throw SysError("dupping stdin");
|
||
|
||
if (options.chdir && chdir((*options.chdir).c_str()) == -1)
|
||
throw SysError("chdir failed");
|
||
if (options.gid && setgid(*options.gid) == -1)
|
||
throw SysError("setgid failed");
|
||
/* Drop all other groups if we're setgid. */
|
||
if (options.gid && setgroups(0, 0) == -1)
|
||
throw SysError("setgroups failed");
|
||
if (options.uid && setuid(*options.uid) == -1)
|
||
throw SysError("setuid failed");
|
||
|
||
Strings args_(options.args);
|
||
args_.push_front(options.program);
|
||
|
||
restoreProcessContext();
|
||
|
||
if (options.searchPath)
|
||
execvp(options.program.c_str(), stringsToCharPtrs(args_).data());
|
||
// This allows you to refer to a program with a pathname relative
|
||
// to the PATH variable.
|
||
else
|
||
execv(options.program.c_str(), stringsToCharPtrs(args_).data());
|
||
|
||
throw SysError("executing '%1%'", options.program);
|
||
}, processOptions);
|
||
|
||
out.writeSide.close();
|
||
|
||
std::thread writerThread;
|
||
|
||
std::promise<void> promise;
|
||
|
||
Finally doJoin([&]() {
|
||
if (writerThread.joinable())
|
||
writerThread.join();
|
||
});
|
||
|
||
|
||
if (source) {
|
||
in.readSide.close();
|
||
writerThread = std::thread([&]() {
|
||
try {
|
||
std::vector<char> buf(8 * 1024);
|
||
while (true) {
|
||
size_t n;
|
||
try {
|
||
n = source->read(buf.data(), buf.size());
|
||
} catch (EndOfFile &) {
|
||
break;
|
||
}
|
||
writeFull(in.writeSide.get(), {buf.data(), n});
|
||
}
|
||
promise.set_value();
|
||
} catch (...) {
|
||
promise.set_exception(std::current_exception());
|
||
}
|
||
in.writeSide.close();
|
||
});
|
||
}
|
||
|
||
if (options.standardOut)
|
||
drainFD(out.readSide.get(), *options.standardOut);
|
||
|
||
/* Wait for the child to finish. */
|
||
int status = pid.wait();
|
||
|
||
/* Wait for the writer thread to finish. */
|
||
if (source) promise.get_future().get();
|
||
|
||
if (status)
|
||
throw ExecError(status, "program '%1%' %2%", options.program, statusToString(status));
|
||
}
|
||
|
||
|
||
void closeMostFDs(const std::set<int> & exceptions)
|
||
{
|
||
#if __linux__
|
||
try {
|
||
for (auto & s : readDirectory("/proc/self/fd")) {
|
||
auto fd = std::stoi(s.name);
|
||
if (!exceptions.count(fd)) {
|
||
debug("closing leaked FD %d", fd);
|
||
close(fd);
|
||
}
|
||
}
|
||
return;
|
||
} catch (SysError &) {
|
||
}
|
||
#endif
|
||
|
||
int maxFD = 0;
|
||
maxFD = sysconf(_SC_OPEN_MAX);
|
||
for (int fd = 0; fd < maxFD; ++fd)
|
||
if (!exceptions.count(fd))
|
||
close(fd); /* ignore result */
|
||
}
|
||
|
||
|
||
void closeOnExec(int fd)
|
||
{
|
||
int prev;
|
||
if ((prev = fcntl(fd, F_GETFD, 0)) == -1 ||
|
||
fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1)
|
||
throw SysError("setting close-on-exec flag");
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
std::atomic<bool> _isInterrupted = false;
|
||
|
||
static thread_local bool interruptThrown = false;
|
||
thread_local std::function<bool()> interruptCheck;
|
||
|
||
void setInterruptThrown()
|
||
{
|
||
interruptThrown = true;
|
||
}
|
||
|
||
void _interrupted()
|
||
{
|
||
/* Block user interrupts while an exception is being handled.
|
||
Throwing an exception while another exception is being handled
|
||
kills the program! */
|
||
if (!interruptThrown && !std::uncaught_exceptions()) {
|
||
interruptThrown = true;
|
||
throw Interrupted("interrupted by the user");
|
||
}
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
template<class C> C tokenizeString(std::string_view s, std::string_view separators)
|
||
{
|
||
C result;
|
||
auto pos = s.find_first_not_of(separators, 0);
|
||
while (pos != std::string_view::npos) {
|
||
auto end = s.find_first_of(separators, pos + 1);
|
||
if (end == std::string_view::npos) end = s.size();
|
||
result.insert(result.end(), std::string(s, pos, end - pos));
|
||
pos = s.find_first_not_of(separators, end);
|
||
}
|
||
return result;
|
||
}
|
||
|
||
template Strings tokenizeString(std::string_view s, std::string_view separators);
|
||
template StringSet tokenizeString(std::string_view s, std::string_view separators);
|
||
template std::vector<std::string> tokenizeString(std::string_view s, std::string_view separators);
|
||
|
||
|
||
std::string chomp(std::string_view s)
|
||
{
|
||
size_t i = s.find_last_not_of(" \n\r\t");
|
||
return i == std::string_view::npos ? "" : std::string(s, 0, i + 1);
|
||
}
|
||
|
||
|
||
std::string trim(std::string_view s, std::string_view whitespace)
|
||
{
|
||
auto i = s.find_first_not_of(whitespace);
|
||
if (i == s.npos) return "";
|
||
auto j = s.find_last_not_of(whitespace);
|
||
return std::string(s, i, j == s.npos ? j : j - i + 1);
|
||
}
|
||
|
||
|
||
std::string replaceStrings(
|
||
std::string res,
|
||
std::string_view from,
|
||
std::string_view to)
|
||
{
|
||
if (from.empty()) return res;
|
||
size_t pos = 0;
|
||
while ((pos = res.find(from, pos)) != std::string::npos) {
|
||
res.replace(pos, from.size(), to);
|
||
pos += to.size();
|
||
}
|
||
return res;
|
||
}
|
||
|
||
|
||
std::string rewriteStrings(std::string s, const StringMap & rewrites)
|
||
{
|
||
for (auto & i : rewrites) {
|
||
if (i.first == i.second) continue;
|
||
size_t j = 0;
|
||
while ((j = s.find(i.first, j)) != std::string::npos)
|
||
s.replace(j, i.first.size(), i.second);
|
||
}
|
||
return s;
|
||
}
|
||
|
||
|
||
std::string statusToString(int status)
|
||
{
|
||
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
|
||
if (WIFEXITED(status))
|
||
return (format("failed with exit code %1%") % WEXITSTATUS(status)).str();
|
||
else if (WIFSIGNALED(status)) {
|
||
int sig = WTERMSIG(status);
|
||
#if HAVE_STRSIGNAL
|
||
const char * description = strsignal(sig);
|
||
return (format("failed due to signal %1% (%2%)") % sig % description).str();
|
||
#else
|
||
return (format("failed due to signal %1%") % sig).str();
|
||
#endif
|
||
}
|
||
else
|
||
return "died abnormally";
|
||
} else return "succeeded";
|
||
}
|
||
|
||
|
||
bool statusOk(int status)
|
||
{
|
||
return WIFEXITED(status) && WEXITSTATUS(status) == 0;
|
||
}
|
||
|
||
|
||
bool hasPrefix(std::string_view s, std::string_view prefix)
|
||
{
|
||
return s.compare(0, prefix.size(), prefix) == 0;
|
||
}
|
||
|
||
|
||
bool hasSuffix(std::string_view s, std::string_view suffix)
|
||
{
|
||
return s.size() >= suffix.size()
|
||
&& s.substr(s.size() - suffix.size()) == suffix;
|
||
}
|
||
|
||
|
||
std::string toLower(const std::string & s)
|
||
{
|
||
std::string r(s);
|
||
for (auto & c : r)
|
||
c = std::tolower(c);
|
||
return r;
|
||
}
|
||
|
||
|
||
std::string shellEscape(const std::string_view s)
|
||
{
|
||
std::string r;
|
||
r.reserve(s.size() + 2);
|
||
r += "'";
|
||
for (auto & i : s)
|
||
if (i == '\'') r += "'\\''"; else r += i;
|
||
r += '\'';
|
||
return r;
|
||
}
|
||
|
||
|
||
void ignoreException()
|
||
{
|
||
/* Make sure no exceptions leave this function.
|
||
printError() also throws when remote is closed. */
|
||
try {
|
||
try {
|
||
throw;
|
||
} catch (std::exception & e) {
|
||
printError("error (ignored): %1%", e.what());
|
||
}
|
||
} catch (...) { }
|
||
}
|
||
|
||
bool shouldANSI()
|
||
{
|
||
return isatty(STDERR_FILENO)
|
||
&& getEnv("TERM").value_or("dumb") != "dumb"
|
||
&& !getEnv("NO_COLOR").has_value();
|
||
}
|
||
|
||
std::string filterANSIEscapes(const std::string & s, bool filterAll, unsigned int width)
|
||
{
|
||
std::string t, e;
|
||
size_t w = 0;
|
||
auto i = s.begin();
|
||
|
||
while (w < (size_t) width && i != s.end()) {
|
||
|
||
if (*i == '\e') {
|
||
std::string e;
|
||
e += *i++;
|
||
char last = 0;
|
||
|
||
if (i != s.end() && *i == '[') {
|
||
e += *i++;
|
||
// eat parameter bytes
|
||
while (i != s.end() && *i >= 0x30 && *i <= 0x3f) e += *i++;
|
||
// eat intermediate bytes
|
||
while (i != s.end() && *i >= 0x20 && *i <= 0x2f) e += *i++;
|
||
// eat final byte
|
||
if (i != s.end() && *i >= 0x40 && *i <= 0x7e) e += last = *i++;
|
||
} else {
|
||
if (i != s.end() && *i >= 0x40 && *i <= 0x5f) e += *i++;
|
||
}
|
||
|
||
if (!filterAll && last == 'm')
|
||
t += e;
|
||
}
|
||
|
||
else if (*i == '\t') {
|
||
i++; t += ' '; w++;
|
||
while (w < (size_t) width && w % 8) {
|
||
t += ' '; w++;
|
||
}
|
||
}
|
||
|
||
else if (*i == '\r' || *i == '\a')
|
||
// do nothing for now
|
||
i++;
|
||
|
||
else {
|
||
w++;
|
||
// Copy one UTF-8 character.
|
||
if ((*i & 0xe0) == 0xc0) {
|
||
t += *i++;
|
||
if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++;
|
||
} else if ((*i & 0xf0) == 0xe0) {
|
||
t += *i++;
|
||
if (i != s.end() && ((*i & 0xc0) == 0x80)) {
|
||
t += *i++;
|
||
if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++;
|
||
}
|
||
} else if ((*i & 0xf8) == 0xf0) {
|
||
t += *i++;
|
||
if (i != s.end() && ((*i & 0xc0) == 0x80)) {
|
||
t += *i++;
|
||
if (i != s.end() && ((*i & 0xc0) == 0x80)) {
|
||
t += *i++;
|
||
if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++;
|
||
}
|
||
}
|
||
} else
|
||
t += *i++;
|
||
}
|
||
}
|
||
|
||
return t;
|
||
}
|
||
|
||
|
||
constexpr char base64Chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
|
||
|
||
std::string base64Encode(std::string_view s)
|
||
{
|
||
std::string res;
|
||
res.reserve((s.size() + 2) / 3 * 4);
|
||
int data = 0, nbits = 0;
|
||
|
||
for (char c : s) {
|
||
data = data << 8 | (unsigned char) c;
|
||
nbits += 8;
|
||
while (nbits >= 6) {
|
||
nbits -= 6;
|
||
res.push_back(base64Chars[data >> nbits & 0x3f]);
|
||
}
|
||
}
|
||
|
||
if (nbits) res.push_back(base64Chars[data << (6 - nbits) & 0x3f]);
|
||
while (res.size() % 4) res.push_back('=');
|
||
|
||
return res;
|
||
}
|
||
|
||
|
||
std::string base64Decode(std::string_view s)
|
||
{
|
||
constexpr char npos = -1;
|
||
constexpr std::array<char, 256> base64DecodeChars = [&]() {
|
||
std::array<char, 256> result{};
|
||
for (auto& c : result)
|
||
c = npos;
|
||
for (int i = 0; i < 64; i++)
|
||
result[base64Chars[i]] = i;
|
||
return result;
|
||
}();
|
||
|
||
std::string res;
|
||
// Some sequences are missing the padding consisting of up to two '='.
|
||
// vvv
|
||
res.reserve((s.size() + 2) / 4 * 3);
|
||
unsigned int d = 0, bits = 0;
|
||
|
||
for (char c : s) {
|
||
if (c == '=') break;
|
||
if (c == '\n') continue;
|
||
|
||
char digit = base64DecodeChars[(unsigned char) c];
|
||
if (digit == npos)
|
||
throw Error("invalid character in Base64 string: '%c'", c);
|
||
|
||
bits += 6;
|
||
d = d << 6 | digit;
|
||
if (bits >= 8) {
|
||
res.push_back(d >> (bits - 8) & 0xff);
|
||
bits -= 8;
|
||
}
|
||
}
|
||
|
||
return res;
|
||
}
|
||
|
||
|
||
std::string stripIndentation(std::string_view s)
|
||
{
|
||
size_t minIndent = 10000;
|
||
size_t curIndent = 0;
|
||
bool atStartOfLine = true;
|
||
|
||
for (auto & c : s) {
|
||
if (atStartOfLine && c == ' ')
|
||
curIndent++;
|
||
else if (c == '\n') {
|
||
if (atStartOfLine)
|
||
minIndent = std::max(minIndent, curIndent);
|
||
curIndent = 0;
|
||
atStartOfLine = true;
|
||
} else {
|
||
if (atStartOfLine) {
|
||
minIndent = std::min(minIndent, curIndent);
|
||
atStartOfLine = false;
|
||
}
|
||
}
|
||
}
|
||
|
||
std::string res;
|
||
|
||
size_t pos = 0;
|
||
while (pos < s.size()) {
|
||
auto eol = s.find('\n', pos);
|
||
if (eol == s.npos) eol = s.size();
|
||
if (eol - pos > minIndent)
|
||
res.append(s.substr(pos + minIndent, eol - pos - minIndent));
|
||
res.push_back('\n');
|
||
pos = eol + 1;
|
||
}
|
||
|
||
return res;
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////
|
||
|
||
static Sync<std::pair<unsigned short, unsigned short>> windowSize{{0, 0}};
|
||
|
||
|
||
static void updateWindowSize()
|
||
{
|
||
struct winsize ws;
|
||
if (ioctl(2, TIOCGWINSZ, &ws) == 0) {
|
||
auto windowSize_(windowSize.lock());
|
||
windowSize_->first = ws.ws_row;
|
||
windowSize_->second = ws.ws_col;
|
||
}
|
||
}
|
||
|
||
|
||
std::pair<unsigned short, unsigned short> getWindowSize()
|
||
{
|
||
return *windowSize.lock();
|
||
}
|
||
|
||
|
||
/* We keep track of interrupt callbacks using integer tokens, so we can iterate
|
||
safely without having to lock the data structure while executing arbitrary
|
||
functions.
|
||
*/
|
||
struct InterruptCallbacks {
|
||
typedef int64_t Token;
|
||
|
||
/* We use unique tokens so that we can't accidentally delete the wrong
|
||
handler because of an erroneous double delete. */
|
||
Token nextToken = 0;
|
||
|
||
/* Used as a list, see InterruptCallbacks comment. */
|
||
std::map<Token, std::function<void()>> callbacks;
|
||
};
|
||
|
||
static Sync<InterruptCallbacks> _interruptCallbacks;
|
||
|
||
static void signalHandlerThread(sigset_t set)
|
||
{
|
||
while (true) {
|
||
int signal = 0;
|
||
sigwait(&set, &signal);
|
||
|
||
if (signal == SIGINT || signal == SIGTERM || signal == SIGHUP)
|
||
triggerInterrupt();
|
||
|
||
else if (signal == SIGWINCH) {
|
||
updateWindowSize();
|
||
}
|
||
}
|
||
}
|
||
|
||
void triggerInterrupt()
|
||
{
|
||
_isInterrupted = true;
|
||
|
||
{
|
||
InterruptCallbacks::Token i = 0;
|
||
while (true) {
|
||
std::function<void()> callback;
|
||
{
|
||
auto interruptCallbacks(_interruptCallbacks.lock());
|
||
auto lb = interruptCallbacks->callbacks.lower_bound(i);
|
||
if (lb == interruptCallbacks->callbacks.end())
|
||
break;
|
||
|
||
callback = lb->second;
|
||
i = lb->first + 1;
|
||
}
|
||
|
||
try {
|
||
callback();
|
||
} catch (...) {
|
||
ignoreException();
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
static sigset_t savedSignalMask;
|
||
|
||
void startSignalHandlerThread()
|
||
{
|
||
updateWindowSize();
|
||
|
||
if (sigprocmask(SIG_BLOCK, nullptr, &savedSignalMask))
|
||
throw SysError("querying signal mask");
|
||
|
||
sigset_t set;
|
||
sigemptyset(&set);
|
||
sigaddset(&set, SIGINT);
|
||
sigaddset(&set, SIGTERM);
|
||
sigaddset(&set, SIGHUP);
|
||
sigaddset(&set, SIGPIPE);
|
||
sigaddset(&set, SIGWINCH);
|
||
if (pthread_sigmask(SIG_BLOCK, &set, nullptr))
|
||
throw SysError("blocking signals");
|
||
|
||
std::thread(signalHandlerThread, set).detach();
|
||
}
|
||
|
||
static void restoreSignals()
|
||
{
|
||
if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr))
|
||
throw SysError("restoring signals");
|
||
}
|
||
|
||
#if __linux__
|
||
rlim_t savedStackSize = 0;
|
||
#endif
|
||
|
||
void setStackSize(size_t stackSize)
|
||
{
|
||
#if __linux__
|
||
struct rlimit limit;
|
||
if (getrlimit(RLIMIT_STACK, &limit) == 0 && limit.rlim_cur < stackSize) {
|
||
savedStackSize = limit.rlim_cur;
|
||
limit.rlim_cur = stackSize;
|
||
setrlimit(RLIMIT_STACK, &limit);
|
||
}
|
||
#endif
|
||
}
|
||
|
||
#if __linux__
|
||
static AutoCloseFD fdSavedMountNamespace;
|
||
#endif
|
||
|
||
void saveMountNamespace()
|
||
{
|
||
#if __linux__
|
||
static std::once_flag done;
|
||
std::call_once(done, []() {
|
||
AutoCloseFD fd = open("/proc/self/ns/mnt", O_RDONLY);
|
||
if (!fd)
|
||
throw SysError("saving parent mount namespace");
|
||
fdSavedMountNamespace = std::move(fd);
|
||
});
|
||
#endif
|
||
}
|
||
|
||
void restoreMountNamespace()
|
||
{
|
||
#if __linux__
|
||
try {
|
||
auto savedCwd = absPath(".");
|
||
|
||
if (fdSavedMountNamespace && setns(fdSavedMountNamespace.get(), CLONE_NEWNS) == -1)
|
||
throw SysError("restoring parent mount namespace");
|
||
if (chdir(savedCwd.c_str()) == -1) {
|
||
throw SysError("restoring cwd");
|
||
}
|
||
} catch (Error & e) {
|
||
debug(e.msg());
|
||
}
|
||
#endif
|
||
}
|
||
|
||
void unshareFilesystem()
|
||
{
|
||
#ifdef __linux__
|
||
if (unshare(CLONE_FS) != 0 && errno != EPERM)
|
||
throw SysError("unsharing filesystem state in download thread");
|
||
#endif
|
||
}
|
||
|
||
void restoreProcessContext(bool restoreMounts)
|
||
{
|
||
restoreSignals();
|
||
if (restoreMounts) {
|
||
restoreMountNamespace();
|
||
}
|
||
|
||
#if __linux__
|
||
if (savedStackSize) {
|
||
struct rlimit limit;
|
||
if (getrlimit(RLIMIT_STACK, &limit) == 0) {
|
||
limit.rlim_cur = savedStackSize;
|
||
setrlimit(RLIMIT_STACK, &limit);
|
||
}
|
||
}
|
||
#endif
|
||
}
|
||
|
||
/* RAII helper to automatically deregister a callback. */
|
||
struct InterruptCallbackImpl : InterruptCallback
|
||
{
|
||
InterruptCallbacks::Token token;
|
||
~InterruptCallbackImpl() override
|
||
{
|
||
auto interruptCallbacks(_interruptCallbacks.lock());
|
||
interruptCallbacks->callbacks.erase(token);
|
||
}
|
||
};
|
||
|
||
std::unique_ptr<InterruptCallback> createInterruptCallback(std::function<void()> callback)
|
||
{
|
||
auto interruptCallbacks(_interruptCallbacks.lock());
|
||
auto token = interruptCallbacks->nextToken++;
|
||
interruptCallbacks->callbacks.emplace(token, callback);
|
||
|
||
auto res = std::make_unique<InterruptCallbackImpl>();
|
||
res->token = token;
|
||
|
||
return std::unique_ptr<InterruptCallback>(res.release());
|
||
}
|
||
|
||
|
||
AutoCloseFD createUnixDomainSocket()
|
||
{
|
||
AutoCloseFD fdSocket = socket(PF_UNIX, SOCK_STREAM
|
||
#ifdef SOCK_CLOEXEC
|
||
| SOCK_CLOEXEC
|
||
#endif
|
||
, 0);
|
||
if (!fdSocket)
|
||
throw SysError("cannot create Unix domain socket");
|
||
closeOnExec(fdSocket.get());
|
||
return fdSocket;
|
||
}
|
||
|
||
|
||
AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode)
|
||
{
|
||
auto fdSocket = nix::createUnixDomainSocket();
|
||
|
||
bind(fdSocket.get(), path);
|
||
|
||
if (chmod(path.c_str(), mode) == -1)
|
||
throw SysError("changing permissions on '%1%'", path);
|
||
|
||
if (listen(fdSocket.get(), 100) == -1)
|
||
throw SysError("cannot listen on socket '%1%'", path);
|
||
|
||
return fdSocket;
|
||
}
|
||
|
||
|
||
void bind(int fd, const std::string & path)
|
||
{
|
||
unlink(path.c_str());
|
||
|
||
struct sockaddr_un addr;
|
||
addr.sun_family = AF_UNIX;
|
||
|
||
if (path.size() + 1 >= sizeof(addr.sun_path)) {
|
||
Pid pid = startProcess([&]() {
|
||
Path dir = dirOf(path);
|
||
if (chdir(dir.c_str()) == -1)
|
||
throw SysError("chdir to '%s' failed", dir);
|
||
std::string base(baseNameOf(path));
|
||
if (base.size() + 1 >= sizeof(addr.sun_path))
|
||
throw Error("socket path '%s' is too long", base);
|
||
memcpy(addr.sun_path, base.c_str(), base.size() + 1);
|
||
if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
|
||
throw SysError("cannot bind to socket '%s'", path);
|
||
_exit(0);
|
||
});
|
||
int status = pid.wait();
|
||
if (status != 0)
|
||
throw Error("cannot bind to socket '%s'", path);
|
||
} else {
|
||
memcpy(addr.sun_path, path.c_str(), path.size() + 1);
|
||
if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
|
||
throw SysError("cannot bind to socket '%s'", path);
|
||
}
|
||
}
|
||
|
||
|
||
void connect(int fd, const std::string & path)
|
||
{
|
||
struct sockaddr_un addr;
|
||
addr.sun_family = AF_UNIX;
|
||
|
||
if (path.size() + 1 >= sizeof(addr.sun_path)) {
|
||
Pid pid = startProcess([&]() {
|
||
Path dir = dirOf(path);
|
||
if (chdir(dir.c_str()) == -1)
|
||
throw SysError("chdir to '%s' failed", dir);
|
||
std::string base(baseNameOf(path));
|
||
if (base.size() + 1 >= sizeof(addr.sun_path))
|
||
throw Error("socket path '%s' is too long", base);
|
||
memcpy(addr.sun_path, base.c_str(), base.size() + 1);
|
||
if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
|
||
throw SysError("cannot connect to socket at '%s'", path);
|
||
_exit(0);
|
||
});
|
||
int status = pid.wait();
|
||
if (status != 0)
|
||
throw Error("cannot connect to socket at '%s'", path);
|
||
} else {
|
||
memcpy(addr.sun_path, path.c_str(), path.size() + 1);
|
||
if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
|
||
throw SysError("cannot connect to socket at '%s'", path);
|
||
}
|
||
}
|
||
|
||
|
||
std::string showBytes(uint64_t bytes)
|
||
{
|
||
return fmt("%.2f MiB", bytes / (1024.0 * 1024.0));
|
||
}
|
||
|
||
|
||
// FIXME: move to libstore/build
|
||
void commonChildInit(Pipe & logPipe)
|
||
{
|
||
logger = makeSimpleLogger();
|
||
|
||
const static std::string pathNullDevice = "/dev/null";
|
||
restoreProcessContext(false);
|
||
|
||
/* Put the child in a separate session (and thus a separate
|
||
process group) so that it has no controlling terminal (meaning
|
||
that e.g. ssh cannot open /dev/tty) and it doesn't receive
|
||
terminal signals. */
|
||
if (setsid() == -1)
|
||
throw SysError("creating a new session");
|
||
|
||
/* Dup the write side of the logger pipe into stderr. */
|
||
if (dup2(logPipe.writeSide.get(), STDERR_FILENO) == -1)
|
||
throw SysError("cannot pipe standard error into log file");
|
||
|
||
/* Dup stderr to stdout. */
|
||
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
|
||
throw SysError("cannot dup stderr into stdout");
|
||
|
||
/* Reroute stdin to /dev/null. */
|
||
int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
|
||
if (fdDevNull == -1)
|
||
throw SysError("cannot open '%1%'", pathNullDevice);
|
||
if (dup2(fdDevNull, STDIN_FILENO) == -1)
|
||
throw SysError("cannot dup null device into stdin");
|
||
close(fdDevNull);
|
||
}
|
||
|
||
}
|