apply various style suggestions by cppcheck

[apt.git] / apt-pkg / contrib / fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 6b54c81f9b6c0a5e87f0c41a16890d62d90a8087..8ec868ec044e771bae88d018db42ec21f9da2d27 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -800,8 +800,9 @@ pid_t ExecFork(std::set<int> KeepFDs)
       signal(SIGCONT,SIG_DFL);
       signal(SIGTSTP,SIG_DFL);
 
       signal(SIGCONT,SIG_DFL);
       signal(SIGTSTP,SIG_DFL);
 

+      long ScOpenMax = sysconf(_SC_OPEN_MAX);

       // Close all of our FDs - just in case
       // Close all of our FDs - just in case

-      for (int K = 3; K != sysconf(_SC_OPEN_MAX); K++)
+      for (int K = 3; K != ScOpenMax; K++)

       {
         if(KeepFDs.find(K) == KeepFDs.end())
            fcntl(K,F_SETFD,FD_CLOEXEC);
       {
         if(KeepFDs.find(K) == KeepFDs.end())
            fcntl(K,F_SETFD,FD_CLOEXEC);


@@ -857,11 +858,7 @@ bool ExecWait(pid_t Pid,const char *Name,bool Reap)
    return true;
 }
                                                                        /*}}}*/
    return true;
 }
                                                                        /*}}}*/

-
-
-// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned     /*{{{*/
-// ---------------------------------------------------------------------
-/* */
+// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned    /*{{{*/

 bool StartsWithGPGClearTextSignature(string const &FileName)
 {
    static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----\n";
 bool StartsWithGPGClearTextSignature(string const &FileName)
 {
    static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----\n";


@@ -877,7 +874,26 @@ bool StartsWithGPGClearTextSignature(string const &FileName)
 
    return true;
 }
 
    return true;
 }

-
+                                                                       /*}}}*/
+// ChangeOwnerAndPermissionOfFile - set file attributes to requested values /*{{{*/
+bool ChangeOwnerAndPermissionOfFile(char const * const requester, char const * const file, char const * const user, char const * const group, mode_t const mode)
+{
+   if (strcmp(file, "/dev/null") == 0)
+      return true;
+   bool Res = true;
+   if (getuid() == 0 && strlen(user) != 0 && strlen(group) != 0) // if we aren't root, we can't chown, so don't try it
+   {
+      // ensure the file is owned by root and has good permissions
+      struct passwd const * const pw = getpwnam(user);
+      struct group const * const gr = getgrnam(group);
+      if (pw != NULL && gr != NULL && chown(file, pw->pw_uid, gr->gr_gid) != 0)
+        Res &= _error->WarningE(requester, "chown to %s:%s of file %s failed", user, group, file);
+   }
+   if (chmod(file, mode) != 0)
+      Res &= _error->WarningE(requester, "chmod 0%o of file %s failed", mode, file);
+   return Res;
+}
+                                                                       /*}}}*/

 
 class FileFdPrivate {                                                  /*{{{*/
        public:
 
 class FileFdPrivate {                                                  /*{{{*/
        public:


@@ -896,7 +912,7 @@ class FileFdPrivate {                                                       /*{{{*/
           bool eof;
           bool compressing;
 
           bool eof;
           bool compressing;
 

-          LZMAFILE() : file(NULL), eof(false), compressing(false) {}
+          LZMAFILE() : file(NULL), eof(false), compressing(false) { buffer[0] = '\0'; }

           ~LZMAFILE() {
              if (compressing == true)
              {
           ~LZMAFILE() {
              if (compressing == true)
              {


@@ -1525,7 +1541,7 @@ bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual)
            int err;
            char const * const errmsg = BZ2_bzerror(d->bz2, &err);
            if (err != BZ_IO_ERROR)
            int err;
            char const * const errmsg = BZ2_bzerror(d->bz2, &err);
            if (err != BZ_IO_ERROR)

-              return FileFdError("BZ2_bzread: %s (%d: %s)", _("Read error"), err, errmsg);
+              return FileFdError("BZ2_bzread: %s %s (%d: %s)", FileName.c_str(), _("Read error"), err, errmsg);

         }
 #endif
 #ifdef HAVE_LZMA
         }
 #endif
 #ifdef HAVE_LZMA


@@ -2035,10 +2051,7 @@ APT_DEPRECATED gzFile FileFd::gzFd() {
 #endif
 }
 
 #endif
 }
 

-
-// Glob - wrapper around "glob()"                                      /*{{{*/
-// ---------------------------------------------------------------------
-/* */
+// Glob - wrapper around "glob()"                                      /*{{{*/

 std::vector<std::string> Glob(std::string const &pattern, int flags)
 {
    std::vector<std::string> result;
 std::vector<std::string> Glob(std::string const &pattern, int flags)
 {
    std::vector<std::string> result;


@@ -2064,8 +2077,7 @@ std::vector<std::string> Glob(std::string const &pattern, int flags)
    return result;
 }
                                                                        /*}}}*/
    return result;
 }
                                                                        /*}}}*/

-
-std::string GetTempDir()
+std::string GetTempDir()                                               /*{{{*/

 {
    const char *tmpdir = getenv("TMPDIR");
 
 {
    const char *tmpdir = getenv("TMPDIR");
 


@@ -2074,15 +2086,17 @@ std::string GetTempDir()
       tmpdir = P_tmpdir;
 #endif
 
       tmpdir = P_tmpdir;
 #endif
 

-   // check that tmpdir is set and exists

    struct stat st;
    struct stat st;

-   if (!tmpdir || strlen(tmpdir) == 0 || stat(tmpdir, &st) != 0)
+   if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
+        stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0 || // exists and is directory
+        access(tmpdir, R_OK | W_OK | X_OK) != 0 // current user has rwx access to directory
+      )

       tmpdir = "/tmp";
 
    return string(tmpdir);
 }
       tmpdir = "/tmp";
 
    return string(tmpdir);
 }

-
-FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)
+                                                                       /*}}}*/
+FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)   /*{{{*/

 {
    char fn[512];
    FileFd *Fd = new FileFd();
 {
    char fn[512];
    FileFd *Fd = new FileFd();


@@ -2106,19 +2120,19 @@ FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)
 
    return Fd;
 }
 
    return Fd;
 }

-
-bool Rename(std::string From, std::string To)
+                                                                       /*}}}*/
+bool Rename(std::string From, std::string To)                          /*{{{*/

 {
    if (rename(From.c_str(),To.c_str()) != 0)
    {
       _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
                     From.c_str(),To.c_str());
       return false;
 {
    if (rename(From.c_str(),To.c_str()) != 0)
    {
       _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
                     From.c_str(),To.c_str());
       return false;

-   }   
+   }

    return true;
 }
    return true;
 }

-
-bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)
+                                                                       /*}}}*/
+bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/*{{{*/

 {
    int fd;
    if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)
 {
    int fd;
    if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)


@@ -2126,10 +2140,8 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)
 
    int Pipe[2] = {-1, -1};
    if(pipe(Pipe) != 0)
 
    int Pipe[2] = {-1, -1};
    if(pipe(Pipe) != 0)

-   {

       return _error->Errno("pipe", _("Failed to create subprocess IPC"));
       return _error->Errno("pipe", _("Failed to create subprocess IPC"));

-      return NULL;
-   }
+

    std::set<int> keep_fds;
    keep_fds.insert(Pipe[0]);
    keep_fds.insert(Pipe[1]);
    std::set<int> keep_fds;
    keep_fds.insert(Pipe[0]);
    keep_fds.insert(Pipe[1]);


@@ -2172,29 +2184,40 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)
 
    return true;
 }
 
    return true;
 }

-
-bool DropPrivs()
+                                                                       /*}}}*/
+bool DropPrivileges()                                                  /*{{{*/

 {
 {

+   if(_config->FindB("Debug::NoDropPrivs", false) == true)
+      return true;
+
+#if __gnu_linux__
+#if defined(PR_SET_NO_NEW_PRIVS) && ( PR_SET_NO_NEW_PRIVS != 38 )
+#error "PR_SET_NO_NEW_PRIVS is defined, but with a different value than expected!"
+#endif
+   // see prctl(2), needs linux3.5 at runtime - magic constant to avoid it at buildtime
+   int ret = prctl(38, 1, 0, 0, 0);
+   // ignore EINVAL - kernel is too old to understand the option
+   if(ret < 0 && errno != EINVAL)
+      _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
+#endif
+
+   // empty setting disables privilege dropping - this also ensures
+   // backward compatibility, see bug #764506
+   const std::string toUser = _config->Find("APT::Sandbox::User");
+   if (toUser.empty())
+      return true;
+

    // uid will be 0 in the end, but gid might be different anyway
    // uid will be 0 in the end, but gid might be different anyway

-   uid_t old_uid = getuid();
-   gid_t old_gid = getgid();
+   uid_t const old_uid = getuid();
+   gid_t const old_gid = getgid();

 
    if (old_uid != 0)
       return true;
 
    if (old_uid != 0)
       return true;

-   if(_config->FindB("Debug::NoDropPrivs", false) == true)
-      return true;

 
 

-   const std::string nobody = _config->Find("APT::User::Nobody", "_apt");
-   struct passwd *pw = getpwnam(nobody.c_str());
+   struct passwd *pw = getpwnam(toUser.c_str());

    if (pw == NULL)
    if (pw == NULL)

-      return _error->Warning("No user %s, can not drop rights", nobody.c_str());
+      return _error->Error("No user %s, can not drop rights", toUser.c_str());

 
 

-#if __gnu_linux__
-   // see prctl(2), needs linux3.5
-   int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0,0, 0);
-   if(ret < 0)
-      _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
-#endif

    // Do not change the order here, it might break things
    if (setgroups(1, &pw->pw_gid))
       return _error->Errno("setgroups", "Failed to setgroups");
    // Do not change the order here, it might break things
    if (setgroups(1, &pw->pw_gid))
       return _error->Errno("setgroups", "Failed to setgroups");


@@ -2231,6 +2254,7 @@ bool DropPrivs()
       return _error->Error("Could not switch effective user");
 
 #ifdef HAVE_GETRESUID
       return _error->Error("Could not switch effective user");
 
 #ifdef HAVE_GETRESUID

+   // verify that the saved set-user-id was changed as well

    uid_t ruid = 0;
    uid_t euid = 0;
    uid_t suid = 0;
    uid_t ruid = 0;
    uid_t euid = 0;
    uid_t suid = 0;


@@ -2241,6 +2265,7 @@ bool DropPrivs()
 #endif
 
 #ifdef HAVE_GETRESGID
 #endif
 
 #ifdef HAVE_GETRESGID

+   // verify that the saved set-group-id was changed as well

    gid_t rgid = 0;
    gid_t egid = 0;
    gid_t sgid = 0;
    gid_t rgid = 0;
    gid_t egid = 0;
    gid_t sgid = 0;


@@ -2259,3 +2284,4 @@ bool DropPrivs()
 
    return true;
 }
 
    return true;
 }

+                                                                       /*}}}*/