From 4c1536d5f1a1bdab72b2b751a466c6e3868ed00b Mon Sep 17 00:00:00 2001
From: Lukas Nykryn <lnykryn@redhat.com>
Date: Mon, 22 Apr 2013 12:33:31 +0200
Subject: [PATCH] ps: possibility to display machine name for a process

Library systemd-login offers possibility to display
the name of the VM or container which process belongs to.

This patch adds output option "sd_machine" which will
show machine name or "-" when the name can not be determined.

To maintain compatibility with non-systemd systems,
procps must be configured with --with-systemd option
to enable this option.
---
 configure.ac |  4 ++--
 ps/output.c  | 16 ++++++++++++++++
 ps/ps.1      |  4 ++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index ea75f01d..17e35d1b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -269,8 +269,8 @@ AC_ARG_WITH([systemd],
   [], [with_systemd=no])
 
 if test "x$with_systemd" != xno; then
-  PKG_CHECK_MODULES([SYSTEMD], [libsystemd-login], [], [
-    AC_CHECK_LIB(systemd-login, sd_pid_get_unit, [have_systemd=yes], [have_systemd=no])
+  PKG_CHECK_MODULES([SYSTEMD], [libsystemd-login >= 202], [], [
+    AC_CHECK_LIB(systemd-login, sd_pid_get_machine_name, [have_systemd=yes], [have_systemd=no])
     if test "x$have_systemd" = xno; then
       AC_MSG_ERROR([systemd support missing/incomplete])
     fi
diff --git a/ps/output.c b/ps/output.c
index 012f5b69..771d6ffc 100644
--- a/ps/output.c
+++ b/ps/output.c
@@ -1224,7 +1224,22 @@ fail:
   return 1;
 }
 
+static int pr_sd_machine(char *restrict const outbuf, const proc_t *restrict const pp){
+  int r;
+  size_t len;
+  char *machine;
 
+  r = sd_pid_get_machine_name(pp->tgid, &machine);
+  if(r<0) goto fail;
+  len = snprintf(outbuf, COLWID, "%s", machine);
+  free(machine);
+  return len;
+
+fail:
+  outbuf[0] = '-';
+  outbuf[1] = '\0';
+  return 1;
+}
 #endif
 /****************** FLASK & seLinux security stuff **********************/
 // move the bulk of this to libproc sometime
@@ -1553,6 +1568,7 @@ static const format_struct format_array[] = {
 {"scnt",      "SCNT",    pr_nop,      sr_nop,     4,   0,    DEC, AN|RIGHT},  /* man page misspelling of scount? */
 {"scount",    "SC",      pr_nop,      sr_nop,     4,   0,    AIX, AN|RIGHT},  /* scnt==scount, DEC claims both */
 #ifdef WITH_SYSTEMD
+{"sd_machine","MACHINE", pr_sd_machine, sr_nop,  31,   0,    LNX, ET|LEFT},
 {"sd_ouid",   "OWNER",   pr_sd_ouid,  sr_nop,     5,   0,    LNX, ET|LEFT},
 {"sd_session","SESSION", pr_sd_session, sr_nop,  11,   0,    LNX, ET|LEFT},
 {"sd_unit",   "UNIT",    pr_sd_unit,  sr_nop,    31,   0,    LNX, ET|LEFT},
diff --git a/ps/ps.1 b/ps/ps.1
index 7d2ce73f..30718a15 100644
--- a/ps/ps.1
+++ b/ps/ps.1
@@ -1489,6 +1489,10 @@ SCHED_FIFO, SCHED_RR, SCHED_BATCH, SCHED_ISO, and SCHED_IDLE are respectively
 displayed as 0, 1, 2, 3, 4, and 5.
 T}
 
+sd_machine	MACHINE	T{
+displays machine name for processes assigned to VM or container.
+T}
+
 sd_ouid	OWNER	T{
 displays the Unix user identifier of the owner of the session of a process.
 T}