X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=fs%2Fcifs%2Flink.c;fp=fs%2Fcifs%2Flink.c;h=85cdbf831e7baca6c3d3fbdb1ac670e69fc595ad;hb=59f40aff7930052a74ddf5c297aa1974b0838529;hp=473ca8033656fc1c8ab14a7a9d78bafd12722217;hpb=291b7c3a02a7eafbb8ea89a2c0e93676d6972926;p=mv-sheeva.git diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 473ca803365..85cdbf831e7 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -28,6 +28,296 @@ #include "cifsproto.h" #include "cifs_debug.h" #include "cifs_fs_sb.h" +#include "md5.h" + +#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1) +#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1)) +#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1)) +#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024) +#define CIFS_MF_SYMLINK_FILE_SIZE \ + (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN) + +#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n" +#define CIFS_MF_SYMLINK_MD5_FORMAT \ + "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n" +#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \ + md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \ + md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \ + md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\ + md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15] + +static int +CIFSParseMFSymlink(const u8 *buf, + unsigned int buf_len, + unsigned int *_link_len, + char **_link_str) +{ + int rc; + unsigned int link_len; + const char *md5_str1; + const char *link_str; + struct MD5Context md5_ctx; + u8 md5_hash[16]; + char md5_str2[34]; + + if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE) + return -EINVAL; + + md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET]; + link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET]; + + rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len); + if (rc != 1) + return -EINVAL; + + cifs_MD5_init(&md5_ctx); + cifs_MD5_update(&md5_ctx, (const u8 *)link_str, link_len); + cifs_MD5_final(md5_hash, &md5_ctx); + + snprintf(md5_str2, sizeof(md5_str2), + CIFS_MF_SYMLINK_MD5_FORMAT, + CIFS_MF_SYMLINK_MD5_ARGS(md5_hash)); + + if (strncmp(md5_str1, md5_str2, 17) != 0) + return -EINVAL; + + if (_link_str) { + *_link_str = kstrndup(link_str, link_len, GFP_KERNEL); + if (!*_link_str) + return -ENOMEM; + } + + *_link_len = link_len; + return 0; +} + +static int +CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str) +{ + unsigned int link_len; + unsigned int ofs; + struct MD5Context md5_ctx; + u8 md5_hash[16]; + + if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE) + return -EINVAL; + + link_len = strlen(link_str); + + if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN) + return -ENAMETOOLONG; + + cifs_MD5_init(&md5_ctx); + cifs_MD5_update(&md5_ctx, (const u8 *)link_str, link_len); + cifs_MD5_final(md5_hash, &md5_ctx); + + snprintf(buf, buf_len, + CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT, + link_len, + CIFS_MF_SYMLINK_MD5_ARGS(md5_hash)); + + ofs = CIFS_MF_SYMLINK_LINK_OFFSET; + memcpy(buf + ofs, link_str, link_len); + + ofs += link_len; + if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) { + buf[ofs] = '\n'; + ofs++; + } + + while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) { + buf[ofs] = ' '; + ofs++; + } + + return 0; +} + +static int +CIFSCreateMFSymLink(const int xid, struct cifsTconInfo *tcon, + const char *fromName, const char *toName, + const struct nls_table *nls_codepage, int remap) +{ + int rc; + int oplock = 0; + __u16 netfid = 0; + u8 *buf; + unsigned int bytes_written = 0; + + buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + rc = CIFSFormatMFSymlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName); + if (rc != 0) { + kfree(buf); + return rc; + } + + rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE, + CREATE_NOT_DIR, &netfid, &oplock, NULL, + nls_codepage, remap); + if (rc != 0) { + kfree(buf); + return rc; + } + + rc = CIFSSMBWrite(xid, tcon, netfid, + CIFS_MF_SYMLINK_FILE_SIZE /* length */, + 0 /* offset */, + &bytes_written, buf, NULL, 0); + CIFSSMBClose(xid, tcon, netfid); + kfree(buf); + if (rc != 0) + return rc; + + if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE) + return -EIO; + + return 0; +} + +static int +CIFSQueryMFSymLink(const int xid, struct cifsTconInfo *tcon, + const unsigned char *searchName, char **symlinkinfo, + const struct nls_table *nls_codepage, int remap) +{ + int rc; + int oplock = 0; + __u16 netfid = 0; + u8 *buf; + char *pbuf; + unsigned int bytes_read = 0; + int buf_type = CIFS_NO_BUFFER; + unsigned int link_len = 0; + FILE_ALL_INFO file_info; + + rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ, + CREATE_NOT_DIR, &netfid, &oplock, &file_info, + nls_codepage, remap); + if (rc != 0) + return rc; + + if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) { + CIFSSMBClose(xid, tcon, netfid); + /* it's not a symlink */ + return -EINVAL; + } + + buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + pbuf = buf; + + rc = CIFSSMBRead(xid, tcon, netfid, + CIFS_MF_SYMLINK_FILE_SIZE /* length */, + 0 /* offset */, + &bytes_read, &pbuf, &buf_type); + CIFSSMBClose(xid, tcon, netfid); + if (rc != 0) { + kfree(buf); + return rc; + } + + rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, symlinkinfo); + kfree(buf); + if (rc != 0) + return rc; + + return 0; +} + +bool +CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr) +{ + if (!(fattr->cf_mode & S_IFREG)) + /* it's not a symlink */ + return false; + + if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE) + /* it's not a symlink */ + return false; + + return true; +} + +int +CIFSCheckMFSymlink(struct cifs_fattr *fattr, + const unsigned char *path, + struct cifs_sb_info *cifs_sb, int xid) +{ + int rc; + int oplock = 0; + __u16 netfid = 0; + struct tcon_link *tlink; + struct cifsTconInfo *pTcon; + u8 *buf; + char *pbuf; + unsigned int bytes_read = 0; + int buf_type = CIFS_NO_BUFFER; + unsigned int link_len = 0; + FILE_ALL_INFO file_info; + + if (!CIFSCouldBeMFSymlink(fattr)) + /* it's not a symlink */ + return 0; + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + pTcon = tlink_tcon(tlink); + + rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ, + CREATE_NOT_DIR, &netfid, &oplock, &file_info, + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & + CIFS_MOUNT_MAP_SPECIAL_CHR); + if (rc != 0) + goto out; + + if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) { + CIFSSMBClose(xid, pTcon, netfid); + /* it's not a symlink */ + goto out; + } + + buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); + if (!buf) { + rc = -ENOMEM; + goto out; + } + pbuf = buf; + + rc = CIFSSMBRead(xid, pTcon, netfid, + CIFS_MF_SYMLINK_FILE_SIZE /* length */, + 0 /* offset */, + &bytes_read, &pbuf, &buf_type); + CIFSSMBClose(xid, pTcon, netfid); + if (rc != 0) { + kfree(buf); + goto out; + } + + rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL); + kfree(buf); + if (rc == -EINVAL) { + /* it's not a symlink */ + rc = 0; + goto out; + } + + if (rc != 0) + goto out; + + /* it is a symlink */ + fattr->cf_eof = link_len; + fattr->cf_mode &= ~S_IFMT; + fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO; + fattr->cf_dtype = DT_LNK; +out: + cifs_put_tlink(tlink); + return rc; +} int cifs_hardlink(struct dentry *old_file, struct inode *inode, @@ -37,17 +327,17 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode, int xid; char *fromName = NULL; char *toName = NULL; - struct cifs_sb_info *cifs_sb_target; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct tcon_link *tlink; struct cifsTconInfo *pTcon; struct cifsInodeInfo *cifsInode; - xid = GetXid(); - - cifs_sb_target = CIFS_SB(inode->i_sb); - pTcon = cifs_sb_target->tcon; + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + pTcon = tlink_tcon(tlink); -/* No need to check for cross device links since server will do that - BB note DFS case in future though (when we may have to check) */ + xid = GetXid(); fromName = build_path_from_dentry(old_file); toName = build_path_from_dentry(direntry); @@ -56,16 +346,15 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode, goto cifs_hl_exit; } -/* if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/ if (pTcon->unix_ext) rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName, - cifs_sb_target->local_nls, - cifs_sb_target->mnt_cifs_flags & + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); else { rc = CIFSCreateHardLink(xid, pTcon, fromName, toName, - cifs_sb_target->local_nls, - cifs_sb_target->mnt_cifs_flags & + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if ((rc == -EIO) || (rc == -EINVAL)) rc = -EOPNOTSUPP; @@ -101,6 +390,7 @@ cifs_hl_exit: kfree(fromName); kfree(toName); FreeXid(xid); + cifs_put_tlink(tlink); return rc; } @@ -113,10 +403,19 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) char *full_path = NULL; char *target_path = NULL; struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); - struct cifsTconInfo *tcon = cifs_sb->tcon; + struct tcon_link *tlink = NULL; + struct cifsTconInfo *tcon; xid = GetXid(); + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + tlink = NULL; + goto out; + } + tcon = tlink_tcon(tlink); + /* * For now, we just handle symlinks with unix extensions enabled. * Eventually we should handle NTFS reparse points, and MacOS @@ -130,7 +429,8 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) * but there doesn't seem to be any harm in allowing the client to * read them. */ - if (!(tcon->ses->capabilities & CAP_UNIX)) { + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) + && !(tcon->ses->capabilities & CAP_UNIX)) { rc = -EACCES; goto out; } @@ -141,8 +441,21 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) cFYI(1, "Full path: %s inode = 0x%p", full_path, inode); - rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path, - cifs_sb->local_nls); + rc = -EACCES; + /* + * First try Minshall+French Symlinks, if configured + * and fallback to UNIX Extensions Symlinks. + */ + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) + rc = CIFSQueryMFSymLink(xid, tcon, full_path, &target_path, + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & + CIFS_MOUNT_MAP_SPECIAL_CHR); + + if ((rc != 0) && (tcon->ses->capabilities & CAP_UNIX)) + rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path, + cifs_sb->local_nls); + kfree(full_path); out: if (rc != 0) { @@ -151,6 +464,8 @@ out: } FreeXid(xid); + if (tlink) + cifs_put_tlink(tlink); nd_set_link(nd, target_path); return NULL; } @@ -160,29 +475,37 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname) { int rc = -EOPNOTSUPP; int xid; - struct cifs_sb_info *cifs_sb; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct tcon_link *tlink; struct cifsTconInfo *pTcon; char *full_path = NULL; struct inode *newinode = NULL; xid = GetXid(); - cifs_sb = CIFS_SB(inode->i_sb); - pTcon = cifs_sb->tcon; + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + goto symlink_exit; + } + pTcon = tlink_tcon(tlink); full_path = build_path_from_dentry(direntry); - if (full_path == NULL) { rc = -ENOMEM; - FreeXid(xid); - return rc; + goto symlink_exit; } cFYI(1, "Full path: %s", full_path); cFYI(1, "symname is %s", symname); /* BB what if DFS and this volume is on different share? BB */ - if (pTcon->unix_ext) + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) + rc = CIFSCreateMFSymLink(xid, pTcon, full_path, symname, + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & + CIFS_MOUNT_MAP_SPECIAL_CHR); + else if (pTcon->unix_ext) rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname, cifs_sb->local_nls); /* else @@ -208,8 +531,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname) d_instantiate(direntry, newinode); } } - +symlink_exit: kfree(full_path); + cifs_put_tlink(tlink); FreeXid(xid); return rc; }