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path: root/fs/cifs/cifs_dfs_ref.c
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Diffstat (limited to 'fs/cifs/cifs_dfs_ref.c')
-rw-r--r--fs/cifs/cifs_dfs_ref.c111
1 files changed, 79 insertions, 32 deletions
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index d2c8eef84f3..85c0a74d034 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -106,7 +106,8 @@ static char *cifs_get_share_name(const char *node_name)
/**
* compose_mount_options - creates mount options for refferral
* @sb_mountdata: parent/root DFS mount options (template)
- * @ref_unc: refferral server UNC
+ * @dentry: point where we are going to mount
+ * @ref: server's referral
* @devname: pointer for saving device name
*
* creates mount options for submount based on template options sb_mountdata
@@ -116,33 +117,39 @@ static char *cifs_get_share_name(const char *node_name)
* Caller is responcible for freeing retunrned value if it is not error.
*/
static char *compose_mount_options(const char *sb_mountdata,
- const char *ref_unc,
+ struct dentry *dentry,
+ const struct dfs_info3_param *ref,
char **devname)
{
int rc;
- char *mountdata;
+ char *mountdata = NULL;
int md_len;
char *tkn_e;
char *srvIP = NULL;
char sep = ',';
int off, noff;
+ char *fullpath;
if (sb_mountdata == NULL)
return ERR_PTR(-EINVAL);
- *devname = cifs_get_share_name(ref_unc);
+ *devname = cifs_get_share_name(ref->node_name);
rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
if (rc != 0) {
- cERROR(1, ("%s: Failed to resolve server part of %s to IP",
- __func__, *devname));
- mountdata = ERR_PTR(rc);
- goto compose_mount_options_out;
+ cERROR(1, ("%s: Failed to resolve server part of %s to IP: %d",
+ __func__, *devname, rc));;
+ goto compose_mount_options_err;
}
- md_len = strlen(sb_mountdata) + strlen(srvIP) + strlen(ref_unc) + 3;
+ /* md_len = strlen(...) + 12 for 'sep+prefixpath='
+ * assuming that we have 'unc=' and 'ip=' in
+ * the original sb_mountdata
+ */
+ md_len = strlen(sb_mountdata) + strlen(srvIP) +
+ strlen(ref->node_name) + 12;
mountdata = kzalloc(md_len+1, GFP_KERNEL);
if (mountdata == NULL) {
- mountdata = ERR_PTR(-ENOMEM);
- goto compose_mount_options_out;
+ rc = -ENOMEM;
+ goto compose_mount_options_err;
}
/* copy all options except of unc,ip,prefixpath */
@@ -152,53 +159,87 @@ static char *compose_mount_options(const char *sb_mountdata,
strncpy(mountdata, sb_mountdata, 5);
off += 5;
}
- while ((tkn_e = strchr(sb_mountdata+off, sep))) {
- noff = (tkn_e - (sb_mountdata+off)) + 1;
- if (strnicmp(sb_mountdata+off, "unc=", 4) == 0) {
+
+ do {
+ tkn_e = strchr(sb_mountdata + off, sep);
+ if (tkn_e == NULL)
+ noff = strlen(sb_mountdata + off);
+ else
+ noff = tkn_e - (sb_mountdata + off) + 1;
+
+ if (strnicmp(sb_mountdata + off, "unc=", 4) == 0) {
off += noff;
continue;
}
- if (strnicmp(sb_mountdata+off, "ip=", 3) == 0) {
+ if (strnicmp(sb_mountdata + off, "ip=", 3) == 0) {
off += noff;
continue;
}
- if (strnicmp(sb_mountdata+off, "prefixpath=", 3) == 0) {
+ if (strnicmp(sb_mountdata + off, "prefixpath=", 11) == 0) {
off += noff;
continue;
}
- strncat(mountdata, sb_mountdata+off, noff);
+ strncat(mountdata, sb_mountdata + off, noff);
off += noff;
- }
- strcat(mountdata, sb_mountdata+off);
+ } while (tkn_e);
+ strcat(mountdata, sb_mountdata + off);
mountdata[md_len] = '\0';
/* copy new IP and ref share name */
- strcat(mountdata, ",ip=");
+ if (mountdata[strlen(mountdata) - 1] != sep)
+ strncat(mountdata, &sep, 1);
+ strcat(mountdata, "ip=");
strcat(mountdata, srvIP);
- strcat(mountdata, ",unc=");
+ strncat(mountdata, &sep, 1);
+ strcat(mountdata, "unc=");
strcat(mountdata, *devname);
/* find & copy prefixpath */
- tkn_e = strchr(ref_unc+2, '\\');
- if (tkn_e) {
- tkn_e = strchr(tkn_e+1, '\\');
- if (tkn_e) {
- strcat(mountdata, ",prefixpath=");
- strcat(mountdata, tkn_e+1);
- }
+ tkn_e = strchr(ref->node_name + 2, '\\');
+ if (tkn_e == NULL) {
+ /* invalid unc, missing share name*/
+ rc = -EINVAL;
+ goto compose_mount_options_err;
}
+ /*
+ * this function gives us a path with a double backslash prefix. We
+ * require a single backslash for DFS. Temporarily increment fullpath
+ * to put it in the proper form and decrement before freeing it.
+ */
+ fullpath = build_path_from_dentry(dentry);
+ if (!fullpath) {
+ rc = -ENOMEM;
+ goto compose_mount_options_err;
+ }
+ ++fullpath;
+ tkn_e = strchr(tkn_e + 1, '\\');
+ if (tkn_e || (strlen(fullpath) - ref->path_consumed)) {
+ strncat(mountdata, &sep, 1);
+ strcat(mountdata, "prefixpath=");
+ if (tkn_e)
+ strcat(mountdata, tkn_e + 1);
+ strcat(mountdata, fullpath + ref->path_consumed);
+ }
+ --fullpath;
+ kfree(fullpath);
+
/*cFYI(1,("%s: parent mountdata: %s", __func__,sb_mountdata));*/
/*cFYI(1, ("%s: submount mountdata: %s", __func__, mountdata ));*/
compose_mount_options_out:
kfree(srvIP);
return mountdata;
+
+compose_mount_options_err:
+ kfree(mountdata);
+ mountdata = ERR_PTR(rc);
+ goto compose_mount_options_out;
}
static struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
- struct dentry *dentry, char *ref_unc)
+ struct dentry *dentry, const struct dfs_info3_param *ref)
{
struct cifs_sb_info *cifs_sb;
struct vfsmount *mnt;
@@ -207,7 +248,7 @@ static struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
mountdata = compose_mount_options(cifs_sb->mountdata,
- ref_unc, &devname);
+ dentry, ref, &devname);
if (IS_ERR(mountdata))
return (struct vfsmount *)mountdata;
@@ -286,13 +327,19 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
goto out_err;
}
+ /*
+ * The MSDFS spec states that paths in DFS referral requests and
+ * responses must be prefixed by a single '\' character instead of
+ * the double backslashes usually used in the UNC. This function
+ * gives us the latter, so we must adjust the result.
+ */
full_path = build_path_from_dentry(dentry);
if (full_path == NULL) {
rc = -ENOMEM;
goto out_err;
}
- rc = get_dfs_path(xid, ses , full_path, cifs_sb->local_nls,
+ rc = get_dfs_path(xid, ses , full_path + 1, cifs_sb->local_nls,
&num_referrals, &referrals,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -310,7 +357,7 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
}
mnt = cifs_dfs_do_refmount(nd->path.mnt,
nd->path.dentry,
- referrals[i].node_name);
+ referrals + i);
cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
__func__,
referrals[i].node_name, mnt));
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-02 13:57:08 +0000