File indexing completed on 2024-04-28 15:22:03

 /*
     This file is part of the KDE project, module kdesu.
     SPDX-FileCopyrightText: 1999, 2000 Geert Jansen <jansen@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-only
 
     client.cpp: A client for kdesud.
 */
 
 #include "client.h"
 
 #include <config-kdesu.h>
 #include <ksu_debug.h>
 
 #include <cerrno>
 #include <sys/socket.h>
 #include <sys/un.h>
 
 #include <QFile>
 #include <QProcess>
 #include <QRegularExpression>
 #include <QStandardPaths>
 #include <qplatformdefs.h>
 
 extern int kdesuDebugArea();
 
 namespace KDESu
 {
 class KDEsuClientPrivate
 {
 public:
     KDEsuClientPrivate()
         : sockfd(-1)
     {
     }
     QString daemon;
     int sockfd;
     QByteArray sock;
 };
 
 #ifndef SUN_LEN
 #define SUN_LEN(ptr) ((QT_SOCKLEN_T)(((struct sockaddr_un *)0)->sun_path) + strlen((ptr)->sun_path))
 #endif
 
 KDEsuClient::KDEsuClient()
     : d(new KDEsuClientPrivate)
 {
 #if HAVE_X11
     QString display = QString::fromLocal8Bit(qgetenv("DISPLAY"));
     if (display.isEmpty()) {
         // we might be on Wayland
         display = QString::fromLocal8Bit(qgetenv("WAYLAND_DISPLAY"));
     }
     if (display.isEmpty()) {
         qCWarning(KSU_LOG) << "[" << __FILE__ << ":" << __LINE__ << "] "
                            << "$DISPLAY is not set.";
         return;
     }
 
     // strip the screen number from the display
     display.remove(QRegularExpression(QStringLiteral("\\.[0-9]+$")));
 #else
     QString display = QStringLiteral("NODISPLAY");
 #endif
 
     d->sock = QFile::encodeName(QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation) + QStringLiteral("/kdesud_") + display);
     connect();
 }
 
 KDEsuClient::~KDEsuClient()
 {
     if (d->sockfd >= 0) {
         close(d->sockfd);
     }
 }
 
 int KDEsuClient::connect()
 {
     if (d->sockfd >= 0) {
         close(d->sockfd);
     }
     if (access(d->sock.constData(), R_OK | W_OK)) {
         d->sockfd = -1;
         return -1;
     }
 
     d->sockfd = socket(PF_UNIX, SOCK_STREAM, 0);
     if (d->sockfd < 0) {
         qCWarning(KSU_LOG) << "[" << __FILE__ << ":" << __LINE__ << "] "
                            << "socket():" << strerror(errno);
         return -1;
     }
     struct sockaddr_un addr;
     addr.sun_family = AF_UNIX;
     strcpy(addr.sun_path, d->sock.constData());
 
     if (QT_SOCKET_CONNECT(d->sockfd, (struct sockaddr *)&addr, SUN_LEN(&addr)) < 0) {
         qCWarning(KSU_LOG) << "[" << __FILE__ << ":" << __LINE__ << "] "
                            << "connect():" << strerror(errno);
         close(d->sockfd);
         d->sockfd = -1;
         return -1;
     }
 
 #if !defined(SO_PEERCRED) || !HAVE_STRUCT_UCRED
 #if HAVE_GETPEEREID
     uid_t euid;
     gid_t egid;
     // Security: if socket exists, we must own it
     if (getpeereid(d->sockfd, &euid, &egid) == 0 && euid != getuid()) {
         qCWarning(KSU_LOG) << "socket not owned by me! socket uid =" << euid;
         close(d->sockfd);
         d->sockfd = -1;
         return -1;
     }
 #else
 #ifdef __GNUC__
 #warning "Using sloppy security checks"
 #endif
     // We check the owner of the socket after we have connected.
     // If the socket was somehow not ours an attacker will be able
     // to delete it after we connect but shouldn't be able to
     // create a socket that is owned by us.
     QT_STATBUF s;
     if (QT_LSTAT(d->sock.constData(), &s) != 0) {
         qCWarning(KSU_LOG) << "stat failed (" << d->sock << ")";
         close(d->sockfd);
         d->sockfd = -1;
         return -1;
     }
     if (s.st_uid != getuid()) {
         qCWarning(KSU_LOG) << "socket not owned by me! socket uid =" << s.st_uid;
         close(d->sockfd);
         d->sockfd = -1;
         return -1;
     }
     if (!S_ISSOCK(s.st_mode)) {
         qCWarning(KSU_LOG) << "socket is not a socket (" << d->sock << ")";
         close(d->sockfd);
         d->sockfd = -1;
         return -1;
     }
 #endif
 #else
     struct ucred cred;
     QT_SOCKLEN_T siz = sizeof(cred);
 
     // Security: if socket exists, we must own it
     if (getsockopt(d->sockfd, SOL_SOCKET, SO_PEERCRED, &cred, &siz) == 0 && cred.uid != getuid()) {
         qCWarning(KSU_LOG) << "socket not owned by me! socket uid =" << cred.uid;
         close(d->sockfd);
         d->sockfd = -1;
         return -1;
     }
 #endif
 
     return 0;
 }
 
 QByteArray KDEsuClient::escape(const QByteArray &str)
 {
     QByteArray copy;
     copy.reserve(str.size() + 4);
     copy.append('"');
     for (const uchar c : str) {
         if (c < 32) {
             copy.append('\\');
             copy.append('^');
             copy.append(c + '@');
         } else {
             if (c == '\\' || c == '"') {
                 copy.append('\\');
             }
             copy.append(c);
         }
     }
     copy.append('"');
     return copy;
 }
 
 int KDEsuClient::command(const QByteArray &cmd, QByteArray *result)
 {
     if (d->sockfd < 0) {
         return -1;
     }
 
     if (send(d->sockfd, cmd.constData(), cmd.length(), 0) != (int)cmd.length()) {
         return -1;
     }
 
     char buf[1024];
     int nbytes = recv(d->sockfd, buf, 1023, 0);
     if (nbytes <= 0) {
         qCWarning(KSU_LOG) << "[" << __FILE__ << ":" << __LINE__ << "] "
                            << "no reply from daemon.";
         return -1;
     }
     buf[nbytes] = '\000';
 
     QByteArray reply = buf;
     if (reply.left(2) != "OK") {
         return -1;
     }
 
     if (result) {
         *result = reply.mid(3, reply.length() - 4);
     }
     return 0;
 }
 
 int KDEsuClient::setPass(const char *pass, int timeout)
 {
     QByteArray cmd = "PASS ";
     cmd += escape(pass);
     cmd += ' ';
     cmd += QByteArray().setNum(timeout);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::exec(const QByteArray &prog, const QByteArray &user, const QByteArray &options, const QList<QByteArray> &env)
 {
     QByteArray cmd;
     cmd = "EXEC ";
     cmd += escape(prog);
     cmd += ' ';
     cmd += escape(user);
     if (!options.isEmpty() || !env.isEmpty()) {
         cmd += ' ';
         cmd += escape(options);
         for (const auto &var : env) {
             cmd += ' ';
             cmd += escape(var);
         }
     }
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::setHost(const QByteArray &host)
 {
     QByteArray cmd = "HOST ";
     cmd += escape(host);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::setPriority(int prio)
 {
     QByteArray cmd;
     cmd += "PRIO ";
     cmd += QByteArray::number(prio);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::setScheduler(int sched)
 {
     QByteArray cmd;
     cmd += "SCHD ";
     cmd += QByteArray::number(sched);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::delCommand(const QByteArray &key, const QByteArray &user)
 {
     QByteArray cmd = "DEL ";
     cmd += escape(key);
     cmd += ' ';
     cmd += escape(user);
     cmd += '\n';
     return command(cmd);
 }
 int KDEsuClient::setVar(const QByteArray &key, const QByteArray &value, int timeout, const QByteArray &group)
 {
     QByteArray cmd = "SET ";
     cmd += escape(key);
     cmd += ' ';
     cmd += escape(value);
     cmd += ' ';
     cmd += escape(group);
     cmd += ' ';
     cmd += QByteArray().setNum(timeout);
     cmd += '\n';
     return command(cmd);
 }
 
 QByteArray KDEsuClient::getVar(const QByteArray &key)
 {
     QByteArray cmd = "GET ";
     cmd += escape(key);
     cmd += '\n';
     QByteArray reply;
     command(cmd, &reply);
     return reply;
 }
 
 QList<QByteArray> KDEsuClient::getKeys(const QByteArray &group)
 {
     QByteArray cmd = "GETK ";
     cmd += escape(group);
     cmd += '\n';
     QByteArray reply;
     command(cmd, &reply);
     int index = 0;
     int pos;
     QList<QByteArray> list;
     if (!reply.isEmpty()) {
         while (1) {
             pos = reply.indexOf('\007', index);
             if (pos == -1) {
                 if (index == 0) {
                     list.append(reply);
                 } else {
                     list.append(reply.mid(index));
                 }
                 break;
             } else {
                 list.append(reply.mid(index, pos - index));
             }
             index = pos + 1;
         }
     }
     return list;
 }
 
 bool KDEsuClient::findGroup(const QByteArray &group)
 {
     QByteArray cmd = "CHKG ";
     cmd += escape(group);
     cmd += '\n';
     if (command(cmd) == -1) {
         return false;
     }
     return true;
 }
 
 int KDEsuClient::delVar(const QByteArray &key)
 {
     QByteArray cmd = "DELV ";
     cmd += escape(key);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::delGroup(const QByteArray &group)
 {
     QByteArray cmd = "DELG ";
     cmd += escape(group);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::delVars(const QByteArray &special_key)
 {
     QByteArray cmd = "DELS ";
     cmd += escape(special_key);
     cmd += '\n';
     return command(cmd);
 }
 
 int KDEsuClient::ping()
 {
     return command("PING\n");
 }
 
 int KDEsuClient::exitCode()
 {
     QByteArray result;
     if (command("EXIT\n", &result) != 0) {
         return -1;
     }
 
     return result.toInt();
 }
 
 int KDEsuClient::stopServer()
 {
     return command("STOP\n");
 }
 
 static QString findDaemon()
 {
     QString daemon = QFile::decodeName(KDE_INSTALL_FULL_LIBEXECDIR_KF "/kdesud");
     if (!QFile::exists(daemon)) { // if not in libexec, find it in PATH
         daemon = QStandardPaths::findExecutable(QStringLiteral("kdesud"));
         if (daemon.isEmpty()) {
             qCWarning(KSU_LOG) << "kdesud daemon not found.";
         }
     }
     return daemon;
 }
 
 #if KDESU_BUILD_DEPRECATED_SINCE(5, 99)
 bool KDEsuClient::isServerSGID()
 {
     return true;
 }
 #endif
 
 int KDEsuClient::startServer()
 {
     if (d->daemon.isEmpty()) {
         d->daemon = findDaemon();
     }
     if (d->daemon.isEmpty()) {
         return -1;
     }
 
     QProcess proc;
     proc.start(d->daemon, QStringList{});
     if (!proc.waitForFinished()) {
         qCCritical(KSU_LOG) << "Couldn't start kdesud!";
         return -1;
     }
 
     connect();
     return proc.exitCode();
 }
 
 } // namespace KDESu