mount.cifs: fix several problems when mounting subdirectories of shares (try 2)

This patch is the second patch to attempt to fix up some of the problems
with mounting subdirectories of shares. The earlier patch didn't handle
this correctly when POSIX extensions were enabled. This one does.

This is a bit of a confusing area since the different components of
a service string have different rules:

1) hostname: no '/' (slash) or '\' (backslash) is allowed to be
	     embedded within the string

2) sharename: same rules as hostname

3) prefixpath: '\' *is* allowed to be embedded in a path component,
	       iff POSIX extensions are enabled. Otherwise, neither
	       character is allowed.

The idea here is to allow either character to act as a delimiter when we
know that the character can't be anything but a delimiter (namely
everywhere up to the start of the prefixpath). The patch will convert
any '\' unconditionally to '/' in the UNC portion of the string.

However, inside the prefixpath, we can't make assumptions about what
constitutes a delimiter because POSIX allows for embedded '\'
characters. So there we don't attempt to do any conversion, and pass the
prefixpath to the kernel as is. Once the kernel determines whether POSIX
extensions are enabled, it can then convert the path if needed and it's
able to do so. A patch to handle this has already been committed to the
cifs-2.6 git tree.

This patch also fixes an annoyance. When you mount a subdir of a share,
mount.cifs munges the device string so that you can't tell what the
prefixpath is. So if I mount:

	//server/share/p1/p2/p3

..then /proc/mounts and mtab will show only:

	//server/share

Finally, it also tries to apply some consistent rules to the uppercasing
of strings.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
(This used to be commit e03d1dfdb80333c071b600245eb749ef5664aa22)

1 files changed, 66 insertions, 24 deletions

diff --git a/source3/client/mount.cifs.c b/source3/client/mount.cifs.c
index e73d90859c..fdee87ae27 100644
--- a/source3/client/mount.cifs.c
+++ b/source3/client/mount.cifs.c
@@ -63,6 +63,8 @@
 #define MS_BIND 4096
 #endif
 
+#define MAX_UNC_LEN 1024
+
 #define CONST_DISCARD(type, ptr)      ((type) ((void *) (ptr)))
 
 const char *thisprogram;
@@ -74,7 +76,6 @@ static int got_ip = 0;
 static int got_unc = 0;
 static int got_uid = 0;
 static int got_gid = 0;
-static int free_share_name = 0;
 static char * user_name = NULL;
 static char * mountpassword = NULL;
 char * domain_name = NULL;
@@ -837,17 +838,31 @@ static char * check_for_domain(char **ppuser)
 	return domainnm;
 }
 
+/* replace all occurances of "from" in a string with "to" */
+static void replace_char(char *string, char from, char to, int maxlen)
+{
+	char *lastchar = string + maxlen;
+	while (string) {
+		string = strchr(string, from);
+		if (string) {
+			*string = to;
+			if (string >= lastchar)
+				return;
+		}
+	}
+}
+
 /* Note that caller frees the returned buffer if necessary */
 static char * parse_server(char ** punc_name)
 {
 	char * unc_name = *punc_name;
-	int length = strnlen(unc_name,1024);
+	int length = strnlen(unc_name, MAX_UNC_LEN);
 	char * share;
 	char * ipaddress_string = NULL;
 	struct hostent * host_entry = NULL;
 	struct in_addr server_ipaddr;
 
-	if(length > 1023) {
+	if(length > (MAX_UNC_LEN - 1)) {
 		printf("mount error: UNC name too long");
 		return NULL;
 	}
@@ -866,7 +881,6 @@ static char * parse_server(char ** punc_name)
 			/* check for nfs syntax ie server:share */
 			share = strchr(unc_name,':');
 			if(share) {
-				free_share_name = 1;
 				*punc_name = (char *)malloc(length+3);
 				if(*punc_name == NULL) {
 					/* put the original string back  if 
@@ -874,9 +888,9 @@ static char * parse_server(char ** punc_name)
 					*punc_name = unc_name;
 					return NULL;
 				}
-					
 				*share = '/';
 				strncpy((*punc_name)+2,unc_name,length);
+				free(unc_name);
 				unc_name = *punc_name;
 				unc_name[length+2] = 0;
 				goto continue_unc_parsing;
@@ -890,15 +904,18 @@ continue_unc_parsing:
 			unc_name[0] = '/';
 			unc_name[1] = '/';
 			unc_name += 2;
-			if ((share = strchr(unc_name, '/')) || 
-				(share = strchr(unc_name,'\\'))) {
+
+			/* allow for either delimiter between host and sharename */
+			if ((share = strpbrk(unc_name, "/\\"))) {
 				*share = 0;  /* temporarily terminate the string */
 				share += 1;
 				if(got_ip == 0) {
 					host_entry = gethostbyname(unc_name);
 				}
-				*(share - 1) = '/'; /* put the slash back */
-				if ((prefixpath = strchr(share, '/'))) {
+				*(share - 1) = '/'; /* put delimiter back */
+
+				/* we don't convert the prefixpath delimiters since '\\' is a valid char in posix paths */
+				if ((prefixpath = strpbrk(share, "/\\"))) {
 					*prefixpath = 0;  /* permanently terminate the string */
 					if (!strlen(++prefixpath))
 						prefixpath = NULL; /* this needs to be done explicitly */
@@ -963,6 +980,25 @@ static struct option longopts[] = {
 	{ NULL, 0, NULL, 0 }
 };
 
+/* convert a string to uppercase. return false if the string
+ * wasn't ASCII or was a NULL ptr */
+static int
+uppercase_string(char *string)
+{
+	if (!string)
+		return 0;
+
+	while (*string) {
+		/* check for unicode */
+		if ((unsigned char) string[0] & 0x80)
+			return 0;
+		*string = toupper((unsigned char) *string);
+		string++;
+	}
+
+	return 1;
+}
+
 int main(int argc, char ** argv)
 {
 	int c;
@@ -975,6 +1011,7 @@ int main(int argc, char ** argv)
 	char * options = NULL;
 	char * resolved_path = NULL;
 	char * temp;
+	char * dev_name;
 	int rc;
 	int rsize = 0;
 	int wsize = 0;
@@ -1011,8 +1048,16 @@ int main(int argc, char ** argv)
 	printf(" node: %s machine: %s sysname %s domain %s\n", sysinfo.nodename,sysinfo.machine,sysinfo.sysname,sysinfo.domainname);
 #endif */
 	if(argc > 2) {
-		share_name = argv[1];
+		dev_name = argv[1];
+		share_name = strndup(argv[1], MAX_UNC_LEN);
+		if (share_name == NULL) {
+			fprintf(stderr, "%s: %s", argv[0], strerror(ENOMEM));
+			exit(1);
+		}
 		mountpoint = argv[2];
+	} else {
+		mount_cifs_usage();
+		exit(1);
 	}
 
 	/* add sharename in opts string as unc= parm */
@@ -1152,7 +1197,7 @@ int main(int argc, char ** argv)
 		}
 	}
 
-	if((argc < 3) || (share_name == NULL) || (mountpoint == NULL)) {
+	if((argc < 3) || (dev_name == NULL) || (mountpoint == NULL)) {
 		mount_cifs_usage();
 		exit(1);
 	}
@@ -1310,10 +1355,12 @@ mount_retry:
 	}
 	if(verboseflag)
 		printf("\nmount.cifs kernel mount options %s \n",options);
-	if(mount(share_name, mountpoint, "cifs", flags, options)) {
-	/* remember to kill daemon on error */
-		char * tmp;
 
+	/* convert all '\\' to '/' in share portion so that /proc/mounts looks pretty */
+	replace_char(dev_name, '\\', '/', strlen(share_name));
+
+	if(mount(dev_name, mountpoint, "cifs", flags, options)) {
+	/* remember to kill daemon on error */
 		switch (errno) {
 		case 0:
 			printf("mount failed but no error number set\n");
@@ -1324,12 +1371,9 @@ mount_retry:
 		case ENXIO:
 			if(retry == 0) {
 				retry = 1;
-				tmp = share_name;
-				while (*tmp && !(((unsigned char)tmp[0]) & 0x80)) {
-					*tmp = toupper((unsigned char)*tmp);
-		        		tmp++;
-				}
-				if(!*tmp) {
+				if (uppercase_string(dev_name) &&
+				    uppercase_string(share_name) &&
+				    uppercase_string(prefixpath)) {
 					printf("retrying with upper case share name\n");
 					goto mount_retry;
 				}
@@ -1343,7 +1387,7 @@ mount_retry:
 	} else {
 		pmntfile = setmntent(MOUNTED, "a+");
 		if(pmntfile) {
-			mountent.mnt_fsname = share_name;
+			mountent.mnt_fsname = dev_name;
 			mountent.mnt_dir = mountpoint;
 			mountent.mnt_type = CONST_DISCARD(char *,"cifs");
 			mountent.mnt_opts = (char *)malloc(220);
@@ -1403,8 +1447,6 @@ mount_exit:
 		free(resolved_path);
 	}
 
-	if(free_share_name) {
-		free(share_name);
-		}
+	free(share_name);
 	return rc;
 }