On Wed, 23 Oct 2019 15:21:45 +0300
"Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx> wrote:
> If KernelShark is running with Root privileges, do not save the settings
> in the standard location. Otherwise the configuration files will be owned
> by Root and later the normal user will have no access to those files.
>
> The patch seems to do the right thing in all cases that I tested, however
> there is definitely something that I do not understand. QDir::homePath()
> always returns the path to the home of the normal user, even if I build
> and run kernelshark as root (sudo -s).
>
> Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx>
> ---
> kernel-shark/src/KsMainWindow.cpp | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
> index 3402764..bd6c338 100644
> --- a/kernel-shark/src/KsMainWindow.cpp
> +++ b/kernel-shark/src/KsMainWindow.cpp
> @@ -69,7 +69,7 @@ KsMainWindow::KsMainWindow(QWidget *parent)
> _contentsAction("Contents", this),
> _bugReportAction("Report a bug", this),
> _deselectShortcut(this),
> - _settings("kernelshark.org", "Kernel Shark") // organization , application
> + _settings(_getCacheDir() + "/setting.ini", QSettings::IniFormat)
> {
> setWindowTitle("Kernel Shark");
> _createActions();
> @@ -431,6 +431,9 @@ QString KsMainWindow::_getCacheDir()
> dir = QStandardPaths::writableLocation(appCachePath);
> dir += "/kernelshark";
>
> + if (geteuid() == 0)
> + dir.replace(QDir::homePath(), "/root");
> +
> if (!QDir(dir).exists())
> lamMakePath(false);
> }
I'll pull this patch in, but this assumes that root is always at /root.
I've had machines where that was not the case. I wonder if we should
add something like this on top of this patch. Not this change directly,
(because this is me just writing C with at C++ compiler ;-), but
something that is more the Qt way...
diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
index bd6c338f..56cf9b9b 100644
--- a/kernel-shark/src/KsMainWindow.cpp
+++ b/kernel-shark/src/KsMainWindow.cpp
@@ -31,6 +31,43 @@
#include "KsCaptureDialog.hpp"
#include "KsAdvFilteringDialog.hpp"
+static QString find_root_home(void)
+{
+ FILE *fp = fopen("/etc/passwd", "r");
+ char *buf;
+ char *sav;
+ char *id;
+ size_t n;
+
+ if (!fp)
+ return QString("/root");
+
+ n = 0;
+ while (getline(&buf, &n, fp) != -1) {
+ /* user */
+ strtok_r(buf, ":", &sav);
+ /* type */
+ strtok_r(NULL, ":", &sav);
+ /* pid */
+ id = strtok_r(NULL, ":", &sav);
+ if (atoi(id) != 0) {
+ n = 0;
+ free(buf);
+ continue;
+ }
+ /* gid */
+ strtok_r(NULL, ":", &sav);
+ /* group */
+ strtok_r(NULL, ":", &sav);
+ /* home */
+ QString ret = QString(strtok_r(NULL, ":", &sav));
+ free(buf);
+ return ret;
+ }
+ free(buf);
+ return QString("/root");
+}
+
/** Create KernelShark Main window. */
KsMainWindow::KsMainWindow(QWidget *parent)
: QMainWindow(parent),
@@ -432,7 +469,8 @@ QString KsMainWindow::_getCacheDir()
dir += "/kernelshark";
if (geteuid() == 0)
- dir.replace(QDir::homePath(), "/root");
+ dir.replace(QDir::homePath(),
+ find_root_home().toStdString().c_str());
if (!QDir(dir).exists())
lamMakePath(false);
This reads the /etc/passwd file and searches for the pid of 0, and
returns the home path for that user. On any error it just
quietly defaults back to "/root".
-- Steve
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