[linux-cifs-client] [PATCH] mount.cifs: fix several problems when
mounting subdirectories of shares
Jeff Layton
jlayton at redhat.com
Tue Nov 13 14:04:33 GMT 2007
This is essentially the same patch as I posted yesterday. The only
difference is that I added the replace_char helper function and now
have the code call it instead of doing the conversion internally.
Thoughts?
-------[snip]-------
CIFS has a few problems when mounting subdirectories of shares:
a) mount.cifs assumes that the prefixpath will always begin with a
forward slash. If it begins with a backslash, then it fails to parse out
the prefixpath and leaves it appended to the sharename. This causes the
mount to fail.
b) if the prefixpath uses '/' as a delimiter, it doesn't convert that to
a "native" prefixpath ('\\' delimiter). The kernel will blindly stuff
this prefix into the beginning of a path when it builds one from a dentry,
and this confuses windows servers (samba doesn't seem to care).
c) 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
d) If the client has to retry the mount with an uppercase sharename, it
doesn't also uppercase the prefixpath (not sure if that's a real issue,
but it seems inconsistent).
The following patch fixes all of these problems. It separates the
"share_name" from the "device_name", and passes the share_name as the
unc= string, and the device_name as the first arg to mount(), and to
setmntent().
It also changes mount.cifs to use '\\' exclusively as a delimiter for
the unc= and prefixpath= options, and to use '/' exclusively as a
delimiter in the device string (seemingly necessary since the kernel
doesn't deal well with backslashes in the device string).
Signed-off-by: Jeff Layton <jlayton at redhat.com>
---
source/client/mount.cifs.c | 90 +++++++++++++++++++++++++++++++-------------
1 files changed, 64 insertions(+), 26 deletions(-)
diff --git a/source/client/mount.cifs.c b/source/client/mount.cifs.c
index eb45ae5..d21b0fe 100644
--- a/source/client/mount.cifs.c
+++ b/source/client/mount.cifs.c
@@ -62,6 +62,8 @@
#define MS_BIND 4096
#endif
+#define MAX_UNC_LEN 1024
+
#define CONST_DISCARD(type, ptr) ((type) ((void *) (ptr)))
const char *thisprogram;
@@ -73,7 +75,6 @@ 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;
@@ -747,17 +748,27 @@ 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)
+{
+ while (string) {
+ string = strchr(string, from);
+ if (string)
+ *string = to;
+ }
+}
+
/* 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;
}
@@ -776,7 +787,6 @@ 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
@@ -784,9 +794,9 @@ 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;
@@ -797,18 +807,21 @@ static char * parse_server(char ** punc_name)
}
} else {
continue_unc_parsing:
- unc_name[0] = '/';
- unc_name[1] = '/';
+ unc_name[0] = '\\';
+ unc_name[1] = '\\';
unc_name += 2;
- if ((share = strchr(unc_name, '/')) ||
- (share = strchr(unc_name,'\\'))) {
+
+ /* convert any '/' in unc to '\\' */
+ replace_char(unc_name, '/', '\\');
+
+ if ((share = strchr(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 */
+ if ((prefixpath = strchr(share, '\\'))) {
*prefixpath = 0; /* permanently terminate the string */
if (!strlen(++prefixpath))
prefixpath = NULL; /* this needs to be done explicitly */
@@ -873,6 +886,25 @@ 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;
@@ -885,6 +917,7 @@ 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;
@@ -920,8 +953,16 @@ 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 */
@@ -1061,7 +1102,7 @@ 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);
}
@@ -1219,10 +1260,12 @@ 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 '/' so that /proc/mounts looks pretty */
+ replace_char(dev_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");
@@ -1233,12 +1276,9 @@ 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;
}
@@ -1252,7 +1292,7 @@ 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);
@@ -1312,9 +1352,7 @@ mount_exit:
free(resolved_path);
}
- if(free_share_name) {
- free(share_name);
- }
+ free(share_name);
return rc;
}
--
1.5.3.3
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