split up help messages for simpler reuse

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

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 4cc8112af9fb99366e28c45914b845b0a395483b..02b27f5cfd2e05a463b9f93518fcc3698d433b8e 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -52,6 +52,7 @@
 
 #include <set>
 #include <algorithm>
 
 #include <set>
 #include <algorithm>

+#include <memory>

 
 #ifdef HAVE_ZLIB
        #include <zlib.h>
 
 #ifdef HAVE_ZLIB
        #include <zlib.h>


@@ -157,24 +158,18 @@ bool CopyFile(FileFd &From,FileFd &To)
    if (From.IsOpen() == false || To.IsOpen() == false ||
         From.Failed() == true || To.Failed() == true)
       return false;
    if (From.IsOpen() == false || To.IsOpen() == false ||
         From.Failed() == true || To.Failed() == true)
       return false;

-   
+

    // Buffered copy between fds
    // Buffered copy between fds

-   SPtrArray<unsigned char> Buf = new unsigned char[64000];
-   unsigned long long Size = From.Size();
-   while (Size != 0)
-   {
-      unsigned long long ToRead = Size;
-      if (Size > 64000)
-        ToRead = 64000;
-      
-      if (From.Read(Buf,ToRead) == false || 
-         To.Write(Buf,ToRead) == false)
+   std::unique_ptr<unsigned char[]> Buf(new unsigned char[64000]);
+   constexpr unsigned long long BufSize = sizeof(Buf.get())/sizeof(Buf.get()[0]);
+   unsigned long long ToRead = 0;
+   do {
+      if (From.Read(Buf.get(),BufSize, &ToRead) == false ||
+         To.Write(Buf.get(),ToRead) == false)

         return false;
         return false;

-      
-      Size -= ToRead;
-   }
+   } while (ToRead != 0);

 
 

-   return true;   
+   return true;

 }
                                                                        /*}}}*/
 // GetLock - Gets a lock file                                          /*{{{*/
 }
                                                                        /*}}}*/
 // GetLock - Gets a lock file                                          /*{{{*/


@@ -670,7 +665,7 @@ string flAbsPath(string File)
    char *p = realpath(File.c_str(), NULL);
    if (p == NULL)
    {
    char *p = realpath(File.c_str(), NULL);
    if (p == NULL)
    {

-      _error->Errno("realpath", "flAbsPath failed");
+      _error->Errno("realpath", "flAbsPath on %s failed", File.c_str());

       return "";
    }
    std::string AbsPath(p);
       return "";
    }
    std::string AbsPath(p);


@@ -2005,12 +2000,13 @@ bool FileFd::Close()
    {
       if ((Flags & Compressed) != Compressed && iFd > 0 && close(iFd) != 0)
         Res &= _error->Errno("close",_("Problem closing the file %s"), FileName.c_str());
    {
       if ((Flags & Compressed) != Compressed && iFd > 0 && close(iFd) != 0)
         Res &= _error->Errno("close",_("Problem closing the file %s"), FileName.c_str());

-      if (d != NULL)
-      {
-        Res &= d->CloseDown(FileName);
-        delete d;
-        d = NULL;
-      }
+   }
+
+   if (d != NULL)
+   {
+      Res &= d->CloseDown(FileName);
+      delete d;
+      d = NULL;

    }
 
    if ((Flags & Replace) == Replace) {
    }
 
    if ((Flags & Replace) == Replace) {


@@ -2121,12 +2117,39 @@ std::string GetTempDir()                                                /*{{{*/
 
    struct stat st;
    if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
 
    struct stat st;
    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
-      )
+        stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0) // exists and is directory
+      tmpdir = "/tmp";
+   else if (geteuid() != 0 && // root can do everything anyway
+        faccessat(-1, tmpdir, R_OK | W_OK | X_OK, AT_EACCESS | AT_SYMLINK_NOFOLLOW) != 0) // current user has rwx access to directory

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

+}
+std::string GetTempDir(std::string const &User)
+{
+   // no need/possibility to drop privs
+   if(getuid() != 0 || User.empty() || User == "root")
+      return GetTempDir();
+
+   struct passwd const * const pw = getpwnam(User.c_str());
+   if (pw == NULL)
+      return GetTempDir();
+
+   gid_t const old_euid = geteuid();
+   gid_t const old_egid = getegid();
+   if (setegid(pw->pw_gid) != 0)
+      _error->Errno("setegid", "setegid %u failed", pw->pw_gid);
+   if (seteuid(pw->pw_uid) != 0)
+      _error->Errno("seteuid", "seteuid %u failed", pw->pw_uid);
+
+   std::string const tmp = GetTempDir();
+
+   if (seteuid(old_euid) != 0)
+      _error->Errno("seteuid", "seteuid %u failed", old_euid);
+   if (setegid(old_egid) != 0)
+      _error->Errno("setegid", "setegid %u failed", old_egid);
+
+   return tmp;

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


@@ -2207,11 +2230,14 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/
    {
       close(Pipe[1]);
       fd = Pipe[0];
    {
       close(Pipe[1]);
       fd = Pipe[0];

-   } else if(Mode == FileFd::WriteOnly)
+   }
+   else if(Mode == FileFd::WriteOnly)

    {
       close(Pipe[0]);
       fd = Pipe[1];
    }
    {
       close(Pipe[0]);
       fd = Pipe[1];
    }

+   else
+      return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only");

    Fd.OpenDescriptor(fd, Mode, FileFd::None, true);
 
    return true;
    Fd.OpenDescriptor(fd, Mode, FileFd::None, true);
 
    return true;


@@ -2251,22 +2277,32 @@ bool DropPrivileges()                                                   /*{{{*/
       return _error->Error("No user %s, can not drop rights", toUser.c_str());
 
    // Do not change the order here, it might break things
       return _error->Error("No user %s, can not drop rights", toUser.c_str());
 
    // Do not change the order here, it might break things

+   // Get rid of all our supplementary groups first

    if (setgroups(1, &pw->pw_gid))
       return _error->Errno("setgroups", "Failed to setgroups");
 
    if (setgroups(1, &pw->pw_gid))
       return _error->Errno("setgroups", "Failed to setgroups");
 

+   // Now change the group ids to the new user
+#ifdef HAVE_SETRESGID
+   if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0)
+      return _error->Errno("setresgid", "Failed to set new group ids");
+#else

    if (setegid(pw->pw_gid) != 0)
       return _error->Errno("setegid", "Failed to setegid");
 
    if (setgid(pw->pw_gid) != 0)
       return _error->Errno("setgid", "Failed to setgid");
    if (setegid(pw->pw_gid) != 0)
       return _error->Errno("setegid", "Failed to setegid");
 
    if (setgid(pw->pw_gid) != 0)
       return _error->Errno("setgid", "Failed to setgid");

+#endif

 
 

+   // Change the user ids to the new user
+#ifdef HAVE_SETRESUID
+   if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0)
+      return _error->Errno("setresuid", "Failed to set new user ids");
+#else

    if (setuid(pw->pw_uid) != 0)
       return _error->Errno("setuid", "Failed to setuid");
    if (setuid(pw->pw_uid) != 0)
       return _error->Errno("setuid", "Failed to setuid");

-
-   // the seteuid() is probably uneeded (at least thats what the linux
-   // man-page says about setuid(2)) but we cargo culted it anyway

    if (seteuid(pw->pw_uid) != 0)
       return _error->Errno("seteuid", "Failed to seteuid");
    if (seteuid(pw->pw_uid) != 0)
       return _error->Errno("seteuid", "Failed to seteuid");

+#endif

 
    // Verify that the user has only a single group, and the correct one
    gid_t groups[1];
 
    // Verify that the user has only a single group, and the correct one
    gid_t groups[1];