From: Florian Forster <octo@collectd.org>
Date: Sun, 17 Mar 2013 14:50:16 +0000 (+0100)
Subject: uuid plugin: Improve parsing of the dmidecode output.
X-Git-Tag: collectd-5.3.0~29
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=5b7a7ff99f191d419cf19df001b81d123c93783f;p=collectd.git

uuid plugin: Improve parsing of the dmidecode output.

The entire business of dividing by sizeof(char) only made the code
unreadable, because by specification sizeof(char) evaluates to 1. The
defines were expanded and the parsing is now less sensitive to
formatting changes in the dmidecode output. Module global variables have
been moved to the top.

Fixes Github issue #267 in the process.
---

diff --git a/src/common.c b/src/common.c
index 82a4f017..d617832c 100644
--- a/src/common.c
+++ b/src/common.c
@@ -361,6 +361,22 @@ int strunescape (char *buf, size_t buf_len)
 	return (0);
 } /* int strunescape */
 
+size_t strstripnewline (char *buffer)
+{
+	size_t buffer_len = strlen (buffer);
+
+	while (buffer_len > 0)
+	{
+		if ((buffer[buffer_len - 1] != '\n')
+				&& (buffer[buffer_len - 1] != '\r'))
+			break;
+		buffer[buffer_len] = 0;
+		buffer_len--;
+	}
+
+	return (buffer_len);
+} /* size_t strstripnewline */
+
 int escape_slashes (char *buf, int buf_len)
 {
 	int i;
diff --git a/src/common.h b/src/common.h
index 2c744363..ae8e311f 100644
--- a/src/common.h
+++ b/src/common.h
@@ -208,6 +208,13 @@ int strsubstitute (char *str, char c_from, char c_to);
  */
 int strunescape (char *buf, size_t buf_len);
 
+/**
+ * Removed trailing newline characters (CR and LF) from buffer, which must be
+ * null terminated. Returns the length of the resulting string.
+ */
+__attribute__((nonnull (1)))
+size_t strstripnewline (char *buffer);
+
 /*
  * NAME
  *   timeval_cmp
diff --git a/src/uuid.c b/src/uuid.c
index cf23f5b3..2df60639 100644
--- a/src/uuid.c
+++ b/src/uuid.c
@@ -36,11 +36,11 @@
 #define UUID_PRINTABLE_COMPACT_LENGTH  (UUID_RAW_LENGTH * 2)
 #define UUID_PRINTABLE_NORMAL_LENGTH  (UUID_PRINTABLE_COMPACT_LENGTH + 4)
 
-#define HANDLE_PREFIX "Handle"
-#define SYSINFO_PREFIX "System Information"
-#define ALT_SYSINFO_PREFIX "\tSystem Information"
-#define UUID_PREFIX "\tUUID:"
-#define ALT_UUID_PREFIX "\t\tUUID:"
+static char *uuidfile = NULL;
+
+static const char *config_keys[] = {
+    "UUIDFile"
+};
 
 static int
 looks_like_a_uuid (const char *uuid)
@@ -65,42 +65,28 @@ static char *
 uuid_parse_dmidecode(FILE *file)
 {
     char line[1024];
-    int inSysInfo = 0;
 
-    for (;;) {
-        if (!fgets(line, sizeof(line)/sizeof(char), file)) {
-            return NULL;
-        }
-        if (strncmp(line, HANDLE_PREFIX,
-                    (sizeof(HANDLE_PREFIX)/sizeof(char))-1) == 0) {
-            /*printf("Got handle %s\n", line);*/
-            inSysInfo = 0;
-        } else if (strncmp(line, SYSINFO_PREFIX,
-                           (sizeof(SYSINFO_PREFIX)/sizeof(char))-1) == 0) {
-            /*printf("Got system info %s\n", line);*/
-            inSysInfo = 1;
-        } else if (strncmp(line, ALT_SYSINFO_PREFIX,
-                           (sizeof(ALT_SYSINFO_PREFIX)/sizeof(char))-1) == 0) {
-            /*printf("Got alt system info %s\n", line);*/
-            inSysInfo = 1;
-        }
-        
-        if (inSysInfo) {
-            if (strncmp(line, UUID_PREFIX,
-                        (sizeof(UUID_PREFIX)/sizeof(char))-1) == 0) {
-                char *uuid = line + (sizeof(UUID_PREFIX)/sizeof(char));
-                /*printf("Got uuid [%s]\n", uuid);*/
-                if (looks_like_a_uuid (uuid))
-                    return strdup (uuid);
-            }
-            if (strncmp(line, ALT_UUID_PREFIX,
-                        (sizeof(ALT_UUID_PREFIX)/sizeof(char))-1) == 0) {
-                char *uuid = line + (sizeof(ALT_UUID_PREFIX)/sizeof(char));
-                /*printf("Got alt uuid [%s]\n", uuid);*/
-                if (looks_like_a_uuid (uuid))
-                    return strdup (uuid);
-            }
-        }
+    while (fgets (line, sizeof (line), file) != NULL)
+    {
+        char *fields[4];
+        int fields_num;
+
+        strstripnewline (line);
+
+        /* Look for a line reading:
+         *   UUID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
+         */
+        fields_num = strsplit (line, fields, STATIC_ARRAY_SIZE (fields));
+        if (fields_num != 2)
+            continue;
+
+        if (strcmp("UUID:", fields[0]) != 0)
+            continue;
+
+        if (!looks_like_a_uuid (fields[1]))
+            continue;
+
+        return strdup (fields[1]);
     }
     return NULL;
 }
@@ -187,23 +173,22 @@ static char *
 uuid_get_from_file(const char *path)
 {
     FILE *file;
-    char uuid[UUID_PRINTABLE_NORMAL_LENGTH+1];
+    char uuid[UUID_PRINTABLE_NORMAL_LENGTH + 1] = "";
 
-    if (!(file = fopen(path, "r"))) {
+    file = fopen (path, "r");
+    if (file == NULL)
         return NULL;
-    }
 
     if (!fgets(uuid, sizeof(uuid), file)) {
         fclose(file);
         return NULL;
     }
     fclose(file);
+    strstripnewline (uuid);
 
     return strdup (uuid);
 }
 
-static char *uuidfile = NULL;
-
 static char *
 uuid_get_local(void)
 {
@@ -231,23 +216,19 @@ uuid_get_local(void)
     return NULL;
 }
 
-static const char *config_keys[] = {
-    "UUIDFile",
-    NULL
-};
-#define NR_CONFIG_KEYS ((sizeof config_keys / sizeof config_keys[0]) - 1)
-
 static int
 uuid_config (const char *key, const char *value)
 {
     if (strcasecmp (key, "UUIDFile") == 0) {
-        if (uuidfile) {
-            ERROR ("UUIDFile given twice in configuration file");
-            return 1;
-        }
-        uuidfile = strdup (value);
-        return 0;
+        char *tmp = strdup (value);
+        if (tmp == NULL)
+            return -1;
+        sfree (uuidfile);
+        uuidfile = tmp;
+    } else {
+        return 1;
     }
+
     return 0;
 }
 
@@ -268,9 +249,9 @@ uuid_init (void)
 
 void module_register (void)
 {
-	plugin_register_config ("uuid", uuid_config,
-                            config_keys, NR_CONFIG_KEYS);
-	plugin_register_init ("uuid", uuid_init);
+    plugin_register_config ("uuid", uuid_config,
+            config_keys, STATIC_ARRAY_SIZE (config_keys));
+    plugin_register_init ("uuid", uuid_init);
 }
 
 /*