linux/fs/ncpfs/ncpsign_kernel.c
Petr Vandrovec 2e54eb96e2 BKL: Remove BKL from ncpfs
Dozen of changes in ncpfs to provide some locking other than BKL.

In readdir cache unlock and mark complete first page as last operation,
so it can be used for synchronization, as code intended.

When updating dentry name on case insensitive filesystems do at least
some basic locking...

Hold i_mutex when updating inode fields.

Push some ncp_conn_is_valid down to ncp_request.  Connection can become
invalid at any moment, and fewer error code paths to test the better.

Use i_size_{read,write} to modify file size.

Set inode's backing_dev_info as ncpfs has its own special bdi.

In ioctl unbreak ioctls invoked on filesystem mounted 'ro' - tests are
for inode writeable or owner match, but were turned to filesystem
writeable and inode writeable or owner match.  Also collect all permission
checks in single place.

Add some locking, and remove comments saying that it would be cool to
add some locks to the code.

Constify some pointers.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-10-04 21:10:52 +02:00

126 lines
3.6 KiB
C

/*
* ncpsign_kernel.c
*
* Arne de Bruijn (arne@knoware.nl), 1997
*
*/
#ifdef CONFIG_NCPFS_PACKET_SIGNING
#include <linux/string.h>
#include <linux/ncp.h>
#include <linux/bitops.h>
#include "ncpsign_kernel.h"
/* i386: 32-bit, little endian, handles mis-alignment */
#ifdef __i386__
#define GET_LE32(p) (*(const int *)(p))
#define PUT_LE32(p,v) { *(int *)(p)=v; }
#else
/* from include/ncplib.h */
#define BVAL(buf,pos) (((const __u8 *)(buf))[pos])
#define PVAL(buf,pos) ((unsigned)BVAL(buf,pos))
#define BSET(buf,pos,val) (((__u8 *)(buf))[pos] = (val))
static inline __u16
WVAL_LH(const __u8 * buf, int pos)
{
return PVAL(buf, pos) | PVAL(buf, pos + 1) << 8;
}
static inline __u32
DVAL_LH(const __u8 * buf, int pos)
{
return WVAL_LH(buf, pos) | WVAL_LH(buf, pos + 2) << 16;
}
static inline void
WSET_LH(__u8 * buf, int pos, __u16 val)
{
BSET(buf, pos, val & 0xff);
BSET(buf, pos + 1, val >> 8);
}
static inline void
DSET_LH(__u8 * buf, int pos, __u32 val)
{
WSET_LH(buf, pos, val & 0xffff);
WSET_LH(buf, pos + 2, val >> 16);
}
#define GET_LE32(p) DVAL_LH(p,0)
#define PUT_LE32(p,v) DSET_LH(p,0,v)
#endif
static void nwsign(char *r_data1, char *r_data2, char *outdata) {
int i;
unsigned int w0,w1,w2,w3;
static int rbit[4]={0, 2, 1, 3};
#ifdef __i386__
unsigned int *data2=(unsigned int *)r_data2;
#else
unsigned int data2[16];
for (i=0;i<16;i++)
data2[i]=GET_LE32(r_data2+(i<<2));
#endif
w0=GET_LE32(r_data1);
w1=GET_LE32(r_data1+4);
w2=GET_LE32(r_data1+8);
w3=GET_LE32(r_data1+12);
for (i=0;i<16;i+=4) {
w0=rol32(w0 + ((w1 & w2) | ((~w1) & w3)) + data2[i+0],3);
w3=rol32(w3 + ((w0 & w1) | ((~w0) & w2)) + data2[i+1],7);
w2=rol32(w2 + ((w3 & w0) | ((~w3) & w1)) + data2[i+2],11);
w1=rol32(w1 + ((w2 & w3) | ((~w2) & w0)) + data2[i+3],19);
}
for (i=0;i<4;i++) {
w0=rol32(w0 + (((w2 | w3) & w1) | (w2 & w3)) + 0x5a827999 + data2[i+0],3);
w3=rol32(w3 + (((w1 | w2) & w0) | (w1 & w2)) + 0x5a827999 + data2[i+4],5);
w2=rol32(w2 + (((w0 | w1) & w3) | (w0 & w1)) + 0x5a827999 + data2[i+8],9);
w1=rol32(w1 + (((w3 | w0) & w2) | (w3 & w0)) + 0x5a827999 + data2[i+12],13);
}
for (i=0;i<4;i++) {
w0=rol32(w0 + ((w1 ^ w2) ^ w3) + 0x6ed9eba1 + data2[rbit[i]+0],3);
w3=rol32(w3 + ((w0 ^ w1) ^ w2) + 0x6ed9eba1 + data2[rbit[i]+8],9);
w2=rol32(w2 + ((w3 ^ w0) ^ w1) + 0x6ed9eba1 + data2[rbit[i]+4],11);
w1=rol32(w1 + ((w2 ^ w3) ^ w0) + 0x6ed9eba1 + data2[rbit[i]+12],15);
}
PUT_LE32(outdata,(w0+GET_LE32(r_data1)) & 0xffffffff);
PUT_LE32(outdata+4,(w1+GET_LE32(r_data1+4)) & 0xffffffff);
PUT_LE32(outdata+8,(w2+GET_LE32(r_data1+8)) & 0xffffffff);
PUT_LE32(outdata+12,(w3+GET_LE32(r_data1+12)) & 0xffffffff);
}
/* Make a signature for the current packet and add it at the end of the */
/* packet. */
void __sign_packet(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, void *sign_buff) {
unsigned char data[64];
memcpy(data, server->sign_root, 8);
*(__u32*)(data + 8) = totalsize;
if (size < 52) {
memcpy(data + 12, packet, size);
memset(data + 12 + size, 0, 52 - size);
} else {
memcpy(data + 12, packet, 52);
}
nwsign(server->sign_last, data, server->sign_last);
memcpy(sign_buff, server->sign_last, 8);
}
int sign_verify_reply(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, const void *sign_buff) {
unsigned char data[64];
unsigned char hash[16];
memcpy(data, server->sign_root, 8);
*(__u32*)(data + 8) = totalsize;
if (size < 52) {
memcpy(data + 12, packet, size);
memset(data + 12 + size, 0, 52 - size);
} else {
memcpy(data + 12, packet, 52);
}
nwsign(server->sign_last, data, hash);
return memcmp(sign_buff, hash, 8);
}
#endif /* CONFIG_NCPFS_PACKET_SIGNING */