[Patch 4/9] Mount support routines used to convert mount options

[Steve Dickson <SteveD@redhat.com>]

commit 06dc48fe691d2147c9b3d505183266662ac17e35
Author: Steve Dickson <steved@redhat.com>
Date:   Mon Mar 9 14:00:34 2009 -0400

    Support routines used to read sections from the configuration file
    and parse them into comma separated mount options.
    
    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mount/Makefile.am b/utils/mount/Makefile.am
index 459fa45..29e993d 100644
--- a/utils/mount/Makefile.am
+++ b/utils/mount/Makefile.am
@@ -12,7 +12,7 @@ EXTRA_DIST = nfsmount.x $(man8_MANS) $(man5_MANS)
 mount_nfs_SOURCES = mount.c error.c network.c fstab.c token.c \
 		    parse_opt.c parse_dev.c \
 		    nfsmount.c nfs4mount.c stropts.c\
-		    nfsumount.c \
+		    nfsumount.c configfile.c \
 		    mount_constants.h error.h network.h fstab.h token.h \
 		    parse_opt.h parse_dev.h \
 		    nfs4_mount.h nfs_mount4.h stropts.h version.h
diff --git a/utils/mount/configfile.c b/utils/mount/configfile.c
new file mode 100644
index 0000000..722eaba
--- /dev/null
+++ b/utils/mount/configfile.c
@@ -0,0 +1,299 @@
+/*
+ * configfile.c -- mount configuration file manipulation 
+ * Copyright (C) 2008 Red Hat <nfs-team@redhat.com>
+ *
+ * - Routines use to create mount options from the mount
+ *   configuration file.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "xlog.h"
+#include "conffile.h"
+
+#define KBYTES(x)     ((x) * (1024))
+#define MEGABYTES(x)  ((x) * (1048576))
+#define GIGABYTES(x)  ((x) * (1073741824))
+
+#ifndef NFSMOUNT_GLOBAL_OPTS
+#define NFSMOUNT_GLOBAL_OPTS "NFSMount_Global_Options"
+#endif
+
+#ifndef MOUNTOPTS_CONFFILE
+#define MOUNTOPTS_CONFFILE "/etc/nfsmount.conf"
+#endif
+char *conf_path = MOUNTOPTS_CONFFILE;
+enum {
+	MNT_NOARG=0,
+	MNT_INTARG,
+	MNT_STRARG,
+	MNT_SPEC,
+	MNT_UNSET
+};
+struct mnt_alias {
+	char *alias;
+	char *opt;
+	int  argtype;
+} mnt_alias_tab[] = {
+	{"background", "bg", MNT_NOARG},
+	{"foreground", "fg", MNT_NOARG},
+	{"sloppy", "sloppy", MNT_NOARG},
+};
+int mnt_alias_sz = (sizeof(mnt_alias_tab)/sizeof(mnt_alias_tab[0]));
+
+/*
+ * See if the option is an alias, if so return the 
+ * real mount option along with the argument type.
+ */
+inline static 
+char *mountopts_alias(char *opt, int *argtype)
+{
+	int i;
+
+	*argtype = MNT_UNSET;
+	for (i=0; i < mnt_alias_sz; i++) {
+		if (strcasecmp(opt, mnt_alias_tab[i].alias) != 0)
+			continue;
+		*argtype = mnt_alias_tab[i].argtype;
+		return mnt_alias_tab[i].opt;
+	}
+	return opt;
+}
+/*
+ * Convert numeric strings that end with 'k', 'm' or 'g'
+ * into numeric strings with the real value. 
+ * Meaning '8k' becomes '8094'.
+ */
+char *mountopts_convert(char *value)
+{
+	unsigned long long factor, num;
+	static char buf[64];
+	char *ch;
+
+	ch = &value[strlen(value)-1];
+	switch (tolower(*ch)) {
+	case 'k':
+		factor = KBYTES(1);
+		break;
+	case 'm':
+		factor = MEGABYTES(1);
+		break;
+	case 'g':
+		factor = GIGABYTES(1);
+		break;
+	default:
+		return value;
+	}
+	*ch = '\0';
+	if (strncmp(value, "0x", 2) == 0) {
+		num = strtol(value, (char **)NULL, 16);
+	} else if (strncmp(value, "0", 1) == 0) {
+		num = strtol(value, (char **)NULL, 8);
+	} else {
+		num = strtol(value, (char **)NULL, 10);
+	}
+	num *= factor;
+	snprintf(buf, 64, "%lld", num);
+
+	return buf;
+}
+
+struct entry {
+	SLIST_ENTRY(entry) entries;
+	char *opt;
+};
+static SLIST_HEAD(shead, entry) head = SLIST_HEAD_INITIALIZER(head);
+static int list_size;
+
+/*
+ * Add option to the link list
+ */
+inline static void 
+add_entry(char *opt)
+{
+	struct entry *entry;
+
+	entry = calloc(1, sizeof(struct entry));
+	if (entry == NULL) {
+		xlog_warn("Unable calloc memory for mount configs"); 
+		return;
+	}
+	entry->opt = strdup(opt);
+	if (entry->opt == NULL) {
+		xlog_warn("Unable calloc memory for mount opts"); 
+		free(entry);
+		return;
+	}
+	SLIST_INSERT_HEAD(&head, entry, entries);
+}
+/*
+ * See if the given entry exists if the link list,
+ * if so return that entry
+ */
+inline static 
+char *lookup_entry(char *opt)
+{
+	struct entry *entry;
+
+	SLIST_FOREACH(entry, &head, entries) {
+		if (strcasecmp(entry->opt, opt) == 0)
+			return opt;
+	}
+	return NULL;
+}
+/*
+ * Free all entries on the link list
+ */
+inline static 
+void free_all(void)
+{
+	struct entry *entry;
+
+	while (!SLIST_EMPTY(&head)) {
+		entry = SLIST_FIRST(&head);
+		SLIST_REMOVE_HEAD(&head, entries);
+		free(entry->opt);
+		free(entry);
+	}
+}
+/*
+ * Parse the given section of the configuration 
+ * file to if there are any mount options set.
+ * If so, added them to link list.
+ */
+static void 
+conf_parse_mntopts(char *section, char *opts)
+{
+	struct conf_list *list;
+	struct conf_list_node *node;
+	char buf[BUFSIZ], *value, *field;
+	int argtype;
+
+	list = conf_get_tag_list(section);
+	TAILQ_FOREACH(node, &list->fields, link) {
+		/*
+		 * Do not overwrite options if already exists 
+		 */
+		snprintf(buf, BUFSIZ, "%s=", node->field);
+		if (strstr(opts, buf) != NULL)
+			continue;
+		if (lookup_entry(node->field) != NULL)
+			continue;
+
+		buf[0] = '\0';
+		value = conf_get_str(section, node->field);
+		field = mountopts_alias(node->field, &argtype);
+		if (strcasecmp(value, "false") == 0) {
+			if (argtype != MNT_NOARG)
+				snprintf(buf, BUFSIZ, "no%s", field);
+		} else if (strcasecmp(value, "true") == 0) {
+			snprintf(buf, BUFSIZ, "%s", field);
+		} else {
+			value = mountopts_convert(value);
+			snprintf(buf, BUFSIZ, "%s=%s", field, value);
+		}
+		if (buf[0] == '\0')
+			continue;
+		/* 
+		 * Keep a running tally of the list size adding 
+		 * one for the ',' that will be appened later
+		 */
+		list_size += strlen(buf) + 1;
+		add_entry(buf);
+	}
+	conf_free_list(list);
+}
+
+/*
+ * Concatenate options from the configuration file with the 
+ * given options by building a link list of options from the
+ * different sections in the conf file. Options that exists 
+ * in the either the given options or link list are not 
+ * overwritten so it matter which when each section is
+ * parsed. 
+ */
+char *conf_get_mntopts(char *spec, char *mount_point, 
+	char *mount_opts)
+{
+	struct entry *entry;
+	char *ptr, *server, *config_opts;
+
+	SLIST_INIT(&head);
+	list_size = 0;
+
+	/*
+	 * First see if there are any mount options relative 
+	 * to the mount point.
+	 */
+	conf_parse_mntopts(mount_point, mount_opts);
+
+	/* 
+	 * Next, see if there are any mount options relative
+	 * to the server
+	 */
+	server = strdup(spec);
+	if (server == NULL) {
+		xlog_warn("conf_get_mountops: Unable calloc memory for server"); 
+		free_all();
+		return mount_opts;
+	}
+	if ((ptr = strchr(server, ':')) != NULL)
+		*ptr='\0';
+	conf_parse_mntopts(server, mount_opts);
+	free(server);
+
+	/*
+	 * Finally process all the global mount options. 
+	 */
+	conf_parse_mntopts(NFSMOUNT_GLOBAL_OPTS, mount_opts);
+
+	/*
+	 * If no mount options were found in the configuration file
+	 * just return what was passed in .
+	 */
+	if (SLIST_EMPTY(&head))
+		return mount_opts;
+
+	/*
+	 * Found options in the configuration file. So
+	 * concatenate the configuration options with the 
+	 * options that were passed in
+	 */
+	config_opts = calloc(1, (list_size+strlen(mount_opts)+1));
+	if (server == NULL) {
+		xlog_warn("conf_get_mountops: Unable calloc memory for config_opts"); 
+		free_all();
+		return mount_opts;
+	}
+	strcat(config_opts, mount_opts);
+	strcat(config_opts, ",");
+
+	SLIST_FOREACH(entry, &head, entries) {
+		strcat(config_opts, entry->opt);
+		strcat(config_opts, ",");
+	}
+	*(strrchr(config_opts, ',')) = '\0';
+
+	free_all();
+	free(mount_opts);
+
+	return config_opts;
+}