From 953bd0f881faa40c415a1f1a9d7e2da739d343ff Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@huhu.verplant.org>
Date: Mon, 6 Oct 2008 11:46:59 +0200
Subject: [PATCH] src/collectd-nagios.c: Improve handling of lines returned
 from `GETVAL'.

Then selecting only certain data sources with the `-d' option, the program
would try to read more lines from the server than the server reports, resulting
in the communication never finishing.

This patch resolves that problem and introduces a couple other error handling
blocks.

Thanks to Fabian Linzberger for pointing this out.
---
 src/collectd-nagios.c | 54 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 41 insertions(+), 13 deletions(-)

diff --git a/src/collectd-nagios.c b/src/collectd-nagios.c
index 1bf5b3f3..ca72a68c 100644
--- a/src/collectd-nagios.c
+++ b/src/collectd-nagios.c
@@ -150,6 +150,7 @@ static int get_values (int *ret_values_num, double **ret_values,
 	char **values_names;
 
 	int i;
+	int j;
 
 	fd = socket (PF_UNIX, SOCK_STREAM, 0);
 	if (fd < 0)
@@ -229,31 +230,58 @@ static int get_values (int *ret_values_num, double **ret_values,
 		free (values);
 		return (-1);
 	}
+	memset (values_names, 0, values_num * sizeof (char *));
 
-	i = 0;
+	i = 0; /* index of the values returned by the server */
+	j = 0; /* number of values in `values_names' and `values' */
 	while (fgets (buffer, sizeof (buffer), fh_in) != NULL)
 	{
-		char *key;
-		char *value;
+		do /* while (0) */
+		{
+			char *key;
+			char *value;
+			char *endptr;
+
+			key = buffer;
 
-		key = buffer;
+			value = strchr (key, '=');
+			if (value == NULL)
+			{
+				fprintf (stderr, "Cannot parse line: %s\n", buffer);
+				break;
+			}
+			*value = 0;
+			value++;
 
-		value = strchr (key, '=');
-		if (value == NULL)
-			continue;
-		*value = '\0'; value++;
+			if (ignore_ds (key) != 0)
+				break;
 
-		if (ignore_ds (key) != 0)
-			continue;
+			endptr = NULL;
+			errno = 0;
+			values[j] = strtod (value, &endptr);
+			if ((endptr == value) || (errno != 0))
+			{
+				fprintf (stderr, "Could not parse buffer "
+						"as number: %s\n", value);
+				break;
+			}
 
-		values_names[i] = strdup (key);
-		values[i] = atof (value);
+			values_names[j] = strdup (key);
+			if (values_names[j] == NULL)
+			{
+				fprintf (stderr, "strdup failed.\n");
+				break;
+			}
+			j++;
+		} while (0);
 
 		i++;
 		if (i >= values_num)
 			break;
 	}
-	values_num = i;
+	/* Set `values_num' to the number of values actually stored in the
+	 * array. */
+	values_num = j;
 
 	fclose (fh_in); fh_in = NULL; fd = -1;
 	fclose (fh_out); fh_out = NULL;
-- 
2.30.2