From 3424464d3e447308f171399302cf76eb573a618f Mon Sep 17 00:00:00 2001

From: Reid wahl <nrwahl@protonmail.com>

Date: Fri, 24 Jul 2020 18:22:24 -0700

Subject: [PATCH] fence_lpar: Fix parse error from long command line

When Pacemaker executes `fence_lpar` and the HMC command line is greater

than 80 characters, a parse error causes agent failure. This can happen

with a long user name and/or long managed system name. It happens only

when Pacemaker spawns the `fence_lpar` process; it does not happen when

`fence_lpar` is run from the CLI.

A long command line gets a carriage return ('\r') added at the 80

character mark and wraps back to the beginning of the line with no line

feed ('\n'), overwriting the displayed characters. `fence_lpar`'s regex

matches handle this fine when it's run from the command line.

The problem is that when Pacemaker spawns fence_lpar, **for some

reason** there are backspace characters in the buffer when we hit the

'\r' character. This seems to overwrite some of the `conn.before`

string. As a result, the regex doesn't match `conn.before`, and the

agent fails.

This patch works around the `conn.before` weirdness by reading and

discarding the first received line **before** any regex processing.

Resolves: RHBZ#1860544

Resolves: RHBZ#1860545

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>

---

 agents/lpar/fence_lpar.py | 33 +++++++++++++++++++++++++++------

 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/agents/lpar/fence_lpar.py b/agents/lpar/fence_lpar.py

index 270bbe3b..9dfabc43 100644

--- a/agents/lpar/fence_lpar.py

+++ b/agents/lpar/fence_lpar.py

@@ -19,6 +19,9 @@

 def get_power_status(conn, options):

 	if options["--hmc-version"] == "3":

 		conn.send("lssyscfg -r lpar -m " + options["--managed"] + " -n " + options["--plug"] + " -F name,state\n")

+

+		# First line (command) may cause parsing issues if long

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

 		try:

@@ -29,6 +32,9 @@ def get_power_status(conn, options):

 	elif options["--hmc-version"] in ["4", "IVM"]:

 		conn.send("lssyscfg -r lpar -m "+ options["--managed"] +

 				" --filter 'lpar_names=" + options["--plug"] + "'\n")

+

+		# First line (command) may cause parsing issues if long

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

 		try:

@@ -49,6 +55,9 @@ def set_power_status(conn, options):

 	if options["--hmc-version"] == "3":

 		conn.send("chsysstate -o " + options["--action"] + " -r lpar -m " + options["--managed"]

 			+ " -n " + options["--plug"] + "\n")

+

+		# First line (command) may cause parsing issues if long

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

 	elif options["--hmc-version"] in ["4", "IVM"]:

 		if options["--action"] == "on":

@@ -60,17 +69,23 @@ def set_power_status(conn, options):

 		else:

 			conn.send("chsysstate -o shutdown -r lpar --immed" +

 				" -m " + options["--managed"] + " -n " + options["--plug"] + "\n")

+

+		# First line (command) may cause parsing issues if long

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

 def get_lpar_list(conn, options):

 	outlets = {}

 	if options["--hmc-version"] == "3":

 		conn.send("query_partition_names -m " + options["--managed"] + "\n")

+

+		## We have to remove first line (command)

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

-		## We have to remove first 3 lines (command + header) and last line (part of new prompt)

+		## We have to remove next 2 lines (header) and last line (part of new prompt)

 		####

-		res = re.search("^.+?\n(.+?\n){2}(.*)\n.*$", conn.before, re.S)

+		res = re.search("^(.+?\n){2}(.*)\n.*$", conn.before, re.S)

 		if res == None:

 			fail_usage("Unable to parse output of list command")

@@ -81,11 +96,14 @@ def get_lpar_list(conn, options):

 	elif options["--hmc-version"] == "4":

 		conn.send("lssyscfg -r lpar -m " + options["--managed"] +

 			" -F name:state\n")

+

+		## We have to remove first line (command)

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

-		## We have to remove first line (command) and last line (part of new prompt)

+		## We have to remove last line (part of new prompt)

 		####

-		res = re.search("^.+?\n(.*)\n.*$", conn.before, re.S)

+		res = re.search("^(.*)\n.*$", conn.before, re.S)

 		if res == None:

 			fail_usage("Unable to parse output of list command")

@@ -100,11 +118,14 @@ def get_lpar_list(conn, options):

 	elif options["--hmc-version"] == "IVM":

 		conn.send("lssyscfg -r lpar -m " + options["--managed"] +

 			" -F name,state\n")

+

+		## We have to remove first line (command)

+		conn.readline()

 		conn.log_expect(options["--command-prompt"], int(options["--power-timeout"]))

-		## We have to remove first line (command) and last line (part of new prompt)

+		## We have to remove last line (part of new prompt)

 		####

-		res = re.search("^.+?\n(.*)\n.*$", conn.before, re.S)

+		res = re.search("^(.*)\n.*$", conn.before, re.S)

 		if res == None:

 			fail_usage("Unable to parse output of list command")