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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 | /* * linux/fs/ncpfs/symlink.c * * Code for allowing symbolic links on NCPFS (i.e. NetWare) * Symbolic links are not supported on native NetWare, so we use an * infrequently-used flag (Sh) and store a two-word magic header in * the file to make sure we don't accidentally use a non-link file * as a link. * * When using the NFS namespace, we set the mode to indicate a symlink and * don't bother with the magic numbers. * * from linux/fs/ext2/symlink.c * * Copyright (C) 1998-99, Frank A. Vorstenbosch * * ncpfs symlink handling code * NLS support (c) 1999 Petr Vandrovec * Modified 2000 Ben Harris, University of Cambridge for NFS NS meta-info * */ #include <asm/uaccess.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/ncp_fs.h> #include <linux/time.h> #include <linux/mm.h> #include <linux/stat.h> #include "ncplib_kernel.h" /* these magic numbers must appear in the symlink file -- this makes it a bit more resilient against the magic attributes being set on random files. */ #define NCP_SYMLINK_MAGIC0 cpu_to_le32(0x6c6d7973) /* "symlnk->" */ #define NCP_SYMLINK_MAGIC1 cpu_to_le32(0x3e2d6b6e) /* ----- read a symbolic link ------------------------------------------ */ static int ncp_symlink_readpage(struct file *file, struct page *page) { struct inode *inode = page->mapping->host; int error, length, len; char *link, *rawlink; char *buf = kmap(page); error = -ENOMEM; rawlink = kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL); if (!rawlink) goto fail; if (ncp_make_open(inode,O_RDONLY)) goto failEIO; error=ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle, 0,NCP_MAX_SYMLINK_SIZE,rawlink,&length); ncp_inode_close(inode); /* Close file handle if no other users... */ ncp_make_closed(inode); if (error) goto failEIO; if (NCP_FINFO(inode)->flags & NCPI_KLUDGE_SYMLINK) { if (length<NCP_MIN_SYMLINK_SIZE || ((__le32 *)rawlink)[0]!=NCP_SYMLINK_MAGIC0 || ((__le32 *)rawlink)[1]!=NCP_SYMLINK_MAGIC1) goto failEIO; link = rawlink + 8; length -= 8; } else { link = rawlink; } len = NCP_MAX_SYMLINK_SIZE; error = ncp_vol2io(NCP_SERVER(inode), buf, &len, link, length, 0); kfree(rawlink); if (error) goto fail; SetPageUptodate(page); kunmap(page); unlock_page(page); return 0; failEIO: error = -EIO; kfree(rawlink); fail: SetPageError(page); kunmap(page); unlock_page(page); return error; } /* * symlinks can't do much... */ const struct address_space_operations ncp_symlink_aops = { .readpage = ncp_symlink_readpage, }; /* ----- create a new symbolic link -------------------------------------- */ int ncp_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct inode *inode; char *rawlink; int length, err, i, outlen; int kludge; int mode; __le32 attr; unsigned int hdr; DPRINTK("ncp_symlink(dir=%p,dentry=%p,symname=%s)\n",dir,dentry,symname); if (ncp_is_nfs_extras(NCP_SERVER(dir), NCP_FINFO(dir)->volNumber)) kludge = 0; else #ifdef CONFIG_NCPFS_EXTRAS if (NCP_SERVER(dir)->m.flags & NCP_MOUNT_SYMLINKS) kludge = 1; else #endif /* EPERM is returned by VFS if symlink procedure does not exist */ return -EPERM; rawlink = kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL); if (!rawlink) return -ENOMEM; if (kludge) { mode = 0; attr = aSHARED | aHIDDEN; ((__le32 *)rawlink)[0]=NCP_SYMLINK_MAGIC0; ((__le32 *)rawlink)[1]=NCP_SYMLINK_MAGIC1; hdr = 8; } else { mode = S_IFLNK | S_IRWXUGO; attr = 0; hdr = 0; } length = strlen(symname); /* map to/from server charset, do not touch upper/lower case as symlink can point out of ncp filesystem */ outlen = NCP_MAX_SYMLINK_SIZE - hdr; err = ncp_io2vol(NCP_SERVER(dir), rawlink + hdr, &outlen, symname, length, 0); if (err) goto failfree; outlen += hdr; err = -EIO; if (ncp_create_new(dir,dentry,mode,0,attr)) { goto failfree; } inode=dentry->d_inode; if (ncp_make_open(inode, O_WRONLY)) goto failfree; if (ncp_write_kernel(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle, 0, outlen, rawlink, &i) || i!=outlen) { goto fail; } ncp_inode_close(inode); ncp_make_closed(inode); kfree(rawlink); return 0; fail:; ncp_inode_close(inode); ncp_make_closed(inode); failfree:; kfree(rawlink); return err; } /* ----- EOF ----- */ |