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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 | /* * 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. * * from linux/fs/ext2/symlink.c * * Copyright (C) 1998-99, Frank A. Vorstenbosch * * ncpfs symlink handling code * NLS support (c) 1999 Petr Vandrovec * */ #include <linux/config.h> #ifdef CONFIG_NCPFS_EXTRAS #include <asm/uaccess.h> #include <asm/segment.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/ncp_fs.h> #include <linux/sched.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 le32_to_cpu(0x6c6d7973) /* "symlnk->" */ #define NCP_SYMLINK_MAGIC1 le32_to_cpu(0x3e2d6b6e) int ncp_create_new(struct inode *dir, struct dentry *dentry, int mode,int attributes); /* ----- read a symbolic link ------------------------------------------ */ static int ncp_symlink_readpage(struct dentry *dentry, struct page *page) { struct inode *inode=dentry->d_inode; int error, length, len, cnt; char *link; char *buf = (char*)kmap(page); error = -EIO; if (ncp_make_open(inode,O_RDONLY)) goto fail; error = -ENOMEM; for (cnt = 0; (link=(char *)kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_NFS))==NULL; cnt++) { if (cnt > 10) goto fail; schedule(); } error=ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle, 0,NCP_MAX_SYMLINK_SIZE,link,&length); if (error) { kfree(link); goto fail; } if (length<NCP_MIN_SYMLINK_SIZE || ((__u32 *)link)[0]!=NCP_SYMLINK_MAGIC0 || ((__u32 *)link)[1]!=NCP_SYMLINK_MAGIC1) { error = -EIO; kfree(link); goto fail; } len = NCP_MAX_SYMLINK_SIZE; error = ncp_vol2io(NCP_SERVER(inode), buf, &len, link+8, length-8, 0); kfree(link); if (error) goto fail; SetPageUptodate(page); kunmap(page); UnlockPage(page); return 0; fail: SetPageError(page); kunmap(page); UnlockPage(page); return error; } /* * symlinks can't do much... */ 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 *link; int length, err, i; #ifdef DEBUG PRINTK("ncp_symlink(dir=%p,dentry=%p,symname=%s)\n",dir,dentry,symname); #endif if (!(NCP_SERVER(dir)->m.flags & NCP_MOUNT_SYMLINKS)) return -EPERM; /* EPERM is returned by VFS if symlink procedure does not exist */ if ((length=strlen(symname))>NCP_MAX_SYMLINK_SIZE-8) return -EINVAL; if ((link=(char *)kmalloc(length+9,GFP_NFS))==NULL) return -ENOMEM; if (ncp_create_new(dir,dentry,0,aSHARED|aHIDDEN)) { kfree(link); return -EIO; } inode=dentry->d_inode; ((__u32 *)link)[0]=NCP_SYMLINK_MAGIC0; ((__u32 *)link)[1]=NCP_SYMLINK_MAGIC1; /* map to/from server charset, do not touch upper/lower case as symlink can point out of ncp filesystem */ length += 1; err = ncp_io2vol(NCP_SERVER(inode),link+8,&length,symname,length-1,0); if (err) { kfree(link); return err; } if(ncp_write_kernel(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle, 0, length+8, link, &i) || i!=length+8) { kfree(link); return -EIO; } kfree(link); return 0; } #endif /* ----- EOF ----- */ |