use a=experimental instead n=experimental in pin documentation

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

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 3e592d94fd349476969cd62b84996c648d19f66b..4cc8112af9fb99366e28c45914b845b0a395483b 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -800,11 +800,26 @@ pid_t ExecFork(std::set<int> KeepFDs)
       signal(SIGCONT,SIG_DFL);
       signal(SIGTSTP,SIG_DFL);
 
-      // Close all of our FDs - just in case
-      for (int K = 3; K != sysconf(_SC_OPEN_MAX); K++)
+      DIR *dir = opendir("/proc/self/fd");
+      if (dir != NULL)
       {
-        if(KeepFDs.find(K) == KeepFDs.end())
-           fcntl(K,F_SETFD,FD_CLOEXEC);
+        struct dirent *ent;
+        while ((ent = readdir(dir)))
+        {
+           int fd = atoi(ent->d_name);
+           // If fd > 0, it was a fd number and not . or ..
+           if (fd >= 3 && KeepFDs.find(fd) == KeepFDs.end())
+              fcntl(fd,F_SETFD,FD_CLOEXEC);
+        }
+        closedir(dir);
+      } else {
+        long ScOpenMax = sysconf(_SC_OPEN_MAX);
+        // Close all of our FDs - just in case
+        for (int K = 3; K != ScOpenMax; K++)
+        {
+           if(KeepFDs.find(K) == KeepFDs.end())
+              fcntl(K,F_SETFD,FD_CLOEXEC);
+        }
       }
    }
    
@@ -874,6 +889,25 @@ 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 +1025,25 @@ 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 */
@@ -2066,36 +2119,37 @@ 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);
 }
                                                                        /*}}}*/
-FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)   /*{{{*/
+FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink, FileFd * const TmpFd)     /*{{{*/
 {
    char fn[512];
-   FileFd *Fd = new FileFd();
+   FileFd * const Fd = TmpFd == NULL ? new FileFd() : TmpFd;
 
-   std::string tempdir = GetTempDir();
-   snprintf(fn, sizeof(fn), "%s/%s.XXXXXX", 
+   std::string const tempdir = GetTempDir();
+   snprintf(fn, sizeof(fn), "%s/%s.XXXXXX",
             tempdir.c_str(), Prefix.c_str());
-   int fd = mkstemp(fn);
+   int const fd = mkstemp(fn);
    if(ImmediateUnlink)
       unlink(fn);
-   if (fd < 0) 
+   if (fd < 0)
    {
       _error->Errno("GetTempFile",_("Unable to mkstemp %s"), fn);
       return NULL;
    }
-   if (!Fd->OpenDescriptor(fd, FileFd::WriteOnly, FileFd::None, true))
+   if (!Fd->OpenDescriptor(fd, FileFd::ReadWrite, FileFd::None, true))
    {
       _error->Errno("GetTempFile",_("Unable to write to %s"),fn);
       return NULL;
    }
-
    return Fd;
 }
                                                                        /*}}}*/
@@ -2179,6 +2233,12 @@ bool DropPrivileges()                                                    /*{{{*/
       _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 const old_uid = getuid();
    gid_t const old_gid = getgid();
@@ -2186,7 +2246,6 @@ bool DropPrivileges()                                                     /*{{{*/
    if (old_uid != 0)
       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());