X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/f8aba23f2e8a4c52869cd3869a716df28267597a..5465192b9aeb1ccea778950ccf2d1b7b32f2cd91:/apt-pkg/contrib/fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 86eec7c36..f40526b5c 100644
--- 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);
 
+      long ScOpenMax = sysconf(_SC_OPEN_MAX);
       // 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);
@@ -874,6 +875,25 @@ bool StartsWithGPGClearTextSignature(string const &FileName)
    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:
@@ -991,6 +1011,25 @@ class FileFdPrivate {							/*{{{*/
 	~FileFdPrivate() { CloseDown(""); }
 };
 									/*}}}*/
+// FileFd Constructors							/*{{{*/
+FileFd::FileFd(std::string FileName,unsigned int const Mode,unsigned long AccessMode) : iFd(-1), Flags(0), d(NULL)
+{
+   Open(FileName,Mode, None, AccessMode);
+}
+FileFd::FileFd(std::string FileName,unsigned int const Mode, CompressMode Compress, unsigned long AccessMode) : iFd(-1), Flags(0), d(NULL)
+{
+   Open(FileName,Mode, Compress, AccessMode);
+}
+FileFd::FileFd() : iFd(-1), Flags(AutoClose), d(NULL) {}
+FileFd::FileFd(int const Fd, unsigned int const Mode, CompressMode Compress) : iFd(-1), Flags(0), d(NULL)
+{
+   OpenDescriptor(Fd, Mode, Compress);
+}
+FileFd::FileFd(int const Fd, bool const AutoClose) : iFd(-1), Flags(0), d(NULL)
+{
+   OpenDescriptor(Fd, ReadWrite, None, AutoClose);
+}
+									/*}}}*/
 // FileFd::Open - Open a file						/*{{{*/
 // ---------------------------------------------------------------------
 /* The most commonly used open mode combinations are given with Mode */
@@ -1521,7 +1560,7 @@ 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)
-	       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
@@ -2066,9 +2105,11 @@ std::string GetTempDir()						/*{{{*/
       tmpdir = P_tmpdir;
 #endif
 
-   // check that tmpdir is set and exists
    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);
@@ -2165,27 +2206,37 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/
 									/*}}}*/
 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_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(_config->FindB("Debug::NoDropPrivs", false) == true)
-      return true;
 
-   const std::string toUser = _config->Find("APT::Sandbox::User", "_apt");
    struct passwd *pw = getpwnam(toUser.c_str());
    if (pw == NULL)
       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);
-   // 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
    // Do not change the order here, it might break things
    if (setgroups(1, &pw->pw_gid))
       return _error->Errno("setgroups", "Failed to setgroups");