[PATCH v2 5/7] nfs-utils: tidy up output of conf_report

[Justin Mitchell <jumitche@redhat.com>]

Previously unused conf_report() function is modified to output
an alphabetically sorted version of the current configuration
to the nominated FILE handle.

Signed-off-by: Justin Mitchell <jumitche@redhat.com>
---
 support/include/conffile.h |   3 +-
 support/nfs/conffile.c     | 293 +++++++++++++++++++++++++++++++--------------
 2 files changed, 207 insertions(+), 89 deletions(-)

diff --git a/support/include/conffile.h b/support/include/conffile.h
index 6baaf9a..bc2d61f 100644
--- a/support/include/conffile.h
+++ b/support/include/conffile.h
@@ -37,6 +37,7 @@
 #include <ctype.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 struct conf_list_node {
 	TAILQ_ENTRY(conf_list_node) link;
@@ -65,7 +66,7 @@ extern void     conf_cleanup(void);
 extern int      conf_match_num(const char *, const char *, int);
 extern int      conf_remove(int, const char *, const char *);
 extern int      conf_remove_section(int, const char *);
-extern void     conf_report(void);
+extern void     conf_report(FILE *);
 
 /*
  * Convert letter from upper case to lower case
diff --git a/support/nfs/conffile.c b/support/nfs/conffile.c
index e65caaf..1e8034a 100644
--- a/support/nfs/conffile.c
+++ b/support/nfs/conffile.c
@@ -1080,117 +1080,234 @@ conf_end(int transaction, int commit)
  * Configuration is "stored in reverse order", so reverse it again.
  */
 struct dumper {
-	char *s, *v;
+	char *section;
+	char *arg;
+	char *tag;
+	char *value;
 	struct dumper *next;
 };
 
+/*
+ * Test if two nodes belong to the same (sub)sections
+ */
+static int
+dumper_section_compare(const struct dumper *nodea, const struct dumper *nodeb)
+{
+	int ret;
+
+	/* missing node, shouldnt happen */
+	if (!nodea || !nodeb)
+		return -1;
+
+	/* no section names at all, they are equal */
+	if (!nodea->section && !nodeb->section)
+		return 0;
+
+	/* if only one has a section name, the blank one goes first */
+	if (!nodea->section && nodeb->section)
+		return -1;
+
+	if (nodea->section && !nodeb->section)
+		return 1;
+
+	/* both have section names, but do they match */
+	ret = strcmp(nodea->section, nodeb->section);
+
+	/* section names differ, that was easy */
+	if (ret != 0)
+		return ret;
+
+	/* sections matched, but how about sub-sections,
+	 * again, if only one has a value the blank goes first
+	 */
+	if (!nodea->arg && nodeb->arg)
+		return -1;
+
+	if (nodea->arg && !nodeb->arg)
+		return  1;
+
+	/* both have sub-section args and they differ */
+	if (nodea->arg && nodeb->arg
+	&& (ret=strcmp(nodea->arg, nodeb->arg))!=0)
+		return ret;
+
+	return 0;
+}
+
+/* If a string starts or ends with a space it should be quoted */
+static bool
+should_escape(const char *text)
+{
+	int len;
+
+	/* no string, no escaping needed */
+	if (!text)
+		return false;
+
+	/* first character is a space */
+	if (isspace(text[0]))
+		return true;
+
+	/* last character is a space */
+	len = strlen(text);
+	if (isspace(text[len-1]))
+		return true;
+
+	return false;
+}
+
 static void
-conf_report_dump(struct dumper *node)
+conf_report_dump_text(struct dumper *head, FILE *ff)
 {
-	/* Recursive, cleanup when we're done.  */
-	if (node->next)
-		conf_report_dump(node->next);
-
-	if (node->v)
-		xlog(LOG_INFO, "%s=\t%s", node->s, node->v);
-	else if (node->s) {
-		xlog(LOG_INFO, "%s", node->s);
-		if (strlen(node->s) > 0)
-			free(node->s);
+	const struct dumper *node = head;
+	const struct dumper *last = NULL;
+
+	for (node=head; node!=NULL; node=node->next) {
+		/* starting a new section, print the section header */
+		if (dumper_section_compare(last, node)!=0) {
+			if (node != head)
+				fprintf(ff, "\n");
+			if (node->arg)
+				fprintf(ff, "[%s \"%s\"]\n", node->section, node->arg);
+			else
+				fprintf(ff, "[%s]\n", node->section);
+		}
+
+		/* now print the tag and its value */
+		fprintf(ff, " %s", node->tag);
+		if (node->value) {
+			if (should_escape(node->value))
+				fprintf(ff, " = \"%s\"", node->value);
+			else
+				fprintf(ff, " = %s", node->value);
+		}
+		fprintf(ff, "\n");
+
+		last = node;
 	}
+}
 
-	free (node);
+/* sort by tag compare function */
+static int
+dumper_compare(const void *a, const void *b)
+{
+	const struct dumper *nodea = *(struct dumper **)a;
+	const struct dumper *nodeb = *(struct dumper **)b;
+	int ret;
+
+	/* missing node, shouldnt happen */
+	if (!nodea || !nodeb)
+		return -1;
+
+	/* are the two nodes in different (sub)sections */
+	ret = dumper_section_compare(nodea, nodeb);
+	if (ret != 0)
+		return ret;
+
+	/* sub-sections match (both blank, or both same)
+	 * so we compare the tag names
+	 */
+
+	/* blank tags shouldnt happen, but paranoia */
+	if (!nodea->tag && !nodeb->tag)
+		return  0;
+
+	/* still shouldnt happen, but use the blank-goes-first logic */
+	if (!nodea->tag &&  nodeb->tag)
+		return -1;
+	if ( nodea->tag && !nodeb->tag)
+		return  1;
+
+	/* last test, compare the tags directly */
+	ret = strcmp(nodea->tag, nodeb->tag);
+	return ret;
 }
 
-void
-conf_report (void)
+/* sort all of the report nodes */
+static struct dumper *
+conf_report_sort(struct dumper *start)
 {
-	struct conf_binding *cb, *last = 0;
-	unsigned int i, len, diff_arg = 0;
-	char *current_section = (char *)0;
-	char *current_arg = (char *)0;
-	struct dumper *dumper, *dnode;
+	struct dumper **list;
+	struct dumper *node;
+	unsigned int count = 0;
+	unsigned int i=0;
+
+	/* how long is this list */
+	for (node=start; node!=NULL; node=node->next)
+		count++;
+
+	/* no need to sort a list with less than 2 items */
+	if (count < 2)
+		return start;
+
+	/* build an array of all the nodes */
+	list = calloc(count, sizeof(struct dumper *));
+	if (!list)
+		goto mem_err;
+
+	for (node=start,i=0; node!=NULL; node=node->next) {
+		list[i++] = node;
+	}
+
+	/* sort the array alphabetically by section and tag */
+	qsort(list, count, sizeof(struct dumper *), dumper_compare);
+
+	/* rebuild the linked list in sorted order */
+	for (i=0; i<count-1; i++) {
+		list[i]->next = list[i+1];
+	}
+	list[count-1]->next = NULL;
+
+	/* remember the new head of list and discard the sorting array */
+	node = list[0];
+	free(list);
 
-	dumper = dnode = (struct dumper *)calloc(1, sizeof *dumper);
-	if (!dumper)
-		goto mem_fail;
+	/* return the new head of list */
+	return node;
+
+mem_err:
+	free(list);
+	return NULL;
+}
+
+/* Output a copy of the current configuration to file */
+void
+conf_report(FILE *outfile)
+{
+	struct conf_binding *cb = NULL;
+	unsigned int i;
+	struct dumper *dumper = NULL, *dnode = NULL;
 
 	xlog(LOG_INFO, "conf_report: dumping running configuration");
 
-	for (i = 0; i < sizeof conf_bindings / sizeof conf_bindings[0]; i++)
+	/* build a linked list of all the config nodes */
+	for (i = 0; i < sizeof conf_bindings / sizeof conf_bindings[0]; i++) {
 		for (cb = LIST_FIRST(&conf_bindings[i]); cb; cb = LIST_NEXT(cb, link)) {
-			if (!cb->is_default) {
-				/* Make sure the Section arugment is the same */
-				if (current_arg && current_section && cb->arg) {
-					if (strcmp(cb->section, current_section) == 0 &&
-						strcmp(cb->arg, current_arg) != 0)
-					diff_arg = 1;
-				}
-				/* Dump this entry.  */
-				if (!current_section || strcmp(cb->section, current_section)
-							|| diff_arg) {
-					if (current_section || diff_arg) {
-						len = strlen (current_section) + 3;
-						if (current_arg)
-							len += strlen(current_arg) + 3;
-						dnode->s = malloc(len);
-						if (!dnode->s)
-							goto mem_fail;
-
-						if (current_arg)
-							snprintf(dnode->s, len, "[%s \"%s\"]",
-								current_section, current_arg);
-						else
-							snprintf(dnode->s, len, "[%s]", current_section);
-
-						dnode->next =
-							(struct dumper *)calloc(1, sizeof (struct dumper));
-						dnode = dnode->next;
-						if (!dnode)
-							goto mem_fail;
-
-						dnode->s = "";
-						dnode->next =
-							(struct dumper *)calloc(1, sizeof (struct dumper));
-						dnode = dnode->next;
-						if (!dnode)
-						goto mem_fail;
-					}
-					current_section = cb->section;
-					current_arg = cb->arg;
-					diff_arg = 0;
-				}
-				dnode->s = cb->tag;
-				dnode->v = cb->value;
-				dnode->next = (struct dumper *)calloc (1, sizeof (struct dumper));
-				dnode = dnode->next;
-				if (!dnode)
-					goto mem_fail;
-				last = cb;
+			struct dumper *newnode = calloc(1, sizeof (struct dumper));
+			if (!newnode)
+				goto mem_fail;
+
+			newnode->next = dumper;
+			dumper = newnode;
+
+			newnode->section = cb->section;
+			newnode->arg = cb->arg;
+			newnode->tag = cb->tag;
+			newnode->value = cb->value;
 		}
 	}
 
-	if (last) {
-		len = strlen(last->section) + 3;
-		if (last->arg)
-			len += strlen(last->arg) + 3;
-		dnode->s = malloc(len);
-		if (!dnode->s)
-			goto mem_fail;
-		if (last->arg)
-			snprintf(dnode->s, len, "[%s \"%s\"]", last->section, last->arg);
-		else
-			snprintf(dnode->s, len, "[%s]", last->section);
-	}
-	conf_report_dump(dumper);
-	return;
+	/* sort the list then print it */
+	dumper = conf_report_sort(dumper);
+	conf_report_dump_text(dumper, outfile);
+	goto cleanup;
 
 mem_fail:
 	xlog_warn("conf_report: malloc/calloc failed");
+cleanup:
+	/* traverse the linked list freeing all the nodes */
 	while ((dnode = dumper) != 0) {
 		dumper = dumper->next;
-		if (dnode->s)
-			free(dnode->s);
 		free(dnode);
 	}
 	return;
-- 
1.8.3.1