forked from Mirror/frr
500 lines
9 KiB
C
500 lines
9 KiB
C
|
#include <zebra.h>
|
|||
|
|
#include <stdlib.h>
|
|||
|
|
#include <time.h>
|
|||
|
|
|
|||
|
|
#include "checksum.h"
|
|||
|
|
|
|||
|
|
struct thread_master *master;
|
|||
|
|
|
|||
|
|
struct acc_vals {
|
|||
|
|
int c0;
|
|||
|
|
int c1;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
struct csum_vals {
|
|||
|
|
struct acc_vals a;
|
|||
|
|
int x;
|
|||
|
|
int y;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
static struct csum_vals ospfd_vals, isisd_vals;
|
|||
|
|
|
|||
|
|
typedef size_t testsz_t;
|
|||
|
|
typedef uint16_t testoff_t;
|
|||
|
|
|
|||
|
|
/* Fletcher Checksum -- Refer to RFC1008. */
|
|||
|
|
#define MODX 4102
|
|||
|
|
|
|||
|
|
/* Accumulator phase of checksum */
|
|||
|
|
static
|
|||
|
|
struct acc_vals
|
|||
|
|
accumulate (u_char *buffer, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
u_int8_t *p;
|
|||
|
|
u_int16_t *csum;
|
|||
|
|
int i, init_len, partial_len;
|
|||
|
|
struct acc_vals ret;
|
|||
|
|
|
|||
|
|
csum = (u_int16_t *) (buffer + off);
|
|||
|
|
*(csum) = 0;
|
|||
|
|
|
|||
|
|
p = buffer;
|
|||
|
|
ret.c0 = 0;
|
|||
|
|
ret.c1 = 0;
|
|||
|
|
init_len = len;
|
|||
|
|
|
|||
|
|
while (len != 0)
|
|||
|
|
{
|
|||
|
|
partial_len = MIN(len, MODX);
|
|||
|
|
|
|||
|
|
for (i = 0; i < partial_len; i++)
|
|||
|
|
{
|
|||
|
|
ret.c0 = ret.c0 + *(p++);
|
|||
|
|
ret.c1 += ret.c0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
ret.c0 = ret.c0 % 255;
|
|||
|
|
ret.c1 = ret.c1 % 255;
|
|||
|
|
|
|||
|
|
len -= partial_len;
|
|||
|
|
}
|
|||
|
|
return ret;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* The final reduction phase.
|
|||
|
|
* This one should be the original ospfd version
|
|||
|
|
*/
|
|||
|
|
static u_int16_t
|
|||
|
|
reduce_ospfd (struct csum_vals *vals, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
#define x vals->x
|
|||
|
|
#define y vals->y
|
|||
|
|
#define c0 vals->a.c0
|
|||
|
|
#define c1 vals->a.c1
|
|||
|
|
|
|||
|
|
x = ((len - off - 1) * c0 - c1) % 255;
|
|||
|
|
|
|||
|
|
if (x <= 0)
|
|||
|
|
x += 255;
|
|||
|
|
y = 510 - c0 - x;
|
|||
|
|
if (y > 255)
|
|||
|
|
y -= 255;
|
|||
|
|
|
|||
|
|
/* take care endian issue. */
|
|||
|
|
return htons ((x << 8) + y);
|
|||
|
|
#undef x
|
|||
|
|
#undef y
|
|||
|
|
#undef c0
|
|||
|
|
#undef c1
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* slightly different concatenation */
|
|||
|
|
static u_int16_t
|
|||
|
|
reduce_ospfd1 (struct csum_vals *vals, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
#define x vals->x
|
|||
|
|
#define y vals->y
|
|||
|
|
#define c0 vals->a.c0
|
|||
|
|
#define c1 vals->a.c1
|
|||
|
|
|
|||
|
|
x = ((len - off - 1) * c0 - c1) % 255;
|
|||
|
|
if (x <= 0)
|
|||
|
|
x += 255;
|
|||
|
|
y = 510 - c0 - x;
|
|||
|
|
if (y > 255)
|
|||
|
|
y -= 255;
|
|||
|
|
|
|||
|
|
/* take care endian issue. */
|
|||
|
|
return htons ((x << 8) | (y & 0xff));
|
|||
|
|
#undef x
|
|||
|
|
#undef y
|
|||
|
|
#undef c0
|
|||
|
|
#undef c1
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* original isisd version */
|
|||
|
|
static u_int16_t
|
|||
|
|
reduce_isisd (struct csum_vals *vals, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
#define x vals->x
|
|||
|
|
#define y vals->y
|
|||
|
|
#define c0 vals->a.c0
|
|||
|
|
#define c1 vals->a.c1
|
|||
|
|
u_int32_t mul;
|
|||
|
|
|
|||
|
|
mul = (len - off)*(c0);
|
|||
|
|
x = mul - c0 - c1;
|
|||
|
|
y = c1 - mul - 1;
|
|||
|
|
|
|||
|
|
if (y > 0)
|
|||
|
|
y++;
|
|||
|
|
if (x < 0)
|
|||
|
|
x--;
|
|||
|
|
|
|||
|
|
x %= 255;
|
|||
|
|
y %= 255;
|
|||
|
|
|
|||
|
|
if (x == 0)
|
|||
|
|
x = 255;
|
|||
|
|
if (y == 0)
|
|||
|
|
y = 1;
|
|||
|
|
|
|||
|
|
return htons ((x << 8) | (y & 0xff));
|
|||
|
|
|
|||
|
|
#undef x
|
|||
|
|
#undef y
|
|||
|
|
#undef c0
|
|||
|
|
#undef c1
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* Is the -1 in y wrong perhaps? */
|
|||
|
|
static u_int16_t
|
|||
|
|
reduce_isisd_yfix (struct csum_vals *vals, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
#define x vals->x
|
|||
|
|
#define y vals->y
|
|||
|
|
#define c0 vals->a.c0
|
|||
|
|
#define c1 vals->a.c1
|
|||
|
|
u_int32_t mul;
|
|||
|
|
|
|||
|
|
mul = (len - off)*(c0);
|
|||
|
|
x = mul - c0 - c1;
|
|||
|
|
y = c1 - mul;
|
|||
|
|
|
|||
|
|
if (y > 0)
|
|||
|
|
y++;
|
|||
|
|
if (x < 0)
|
|||
|
|
x--;
|
|||
|
|
|
|||
|
|
x %= 255;
|
|||
|
|
y %= 255;
|
|||
|
|
|
|||
|
|
if (x == 0)
|
|||
|
|
x = 255;
|
|||
|
|
if (y == 0)
|
|||
|
|
y = 1;
|
|||
|
|
|
|||
|
|
return htons ((x << 8) | (y & 0xff));
|
|||
|
|
|
|||
|
|
#undef x
|
|||
|
|
#undef y
|
|||
|
|
#undef c0
|
|||
|
|
#undef c1
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* Move the mods yp */
|
|||
|
|
static u_int16_t
|
|||
|
|
reduce_isisd_mod (struct csum_vals *vals, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
#define x vals->x
|
|||
|
|
#define y vals->y
|
|||
|
|
#define c0 vals->a.c0
|
|||
|
|
#define c1 vals->a.c1
|
|||
|
|
u_int32_t mul;
|
|||
|
|
|
|||
|
|
mul = (len - off)*(c0);
|
|||
|
|
x = mul - c1 - c0;
|
|||
|
|
y = c1 - mul - 1;
|
|||
|
|
|
|||
|
|
x %= 255;
|
|||
|
|
y %= 255;
|
|||
|
|
|
|||
|
|
if (y > 0)
|
|||
|
|
y++;
|
|||
|
|
if (x < 0)
|
|||
|
|
x--;
|
|||
|
|
|
|||
|
|
if (x == 0)
|
|||
|
|
x = 255;
|
|||
|
|
if (y == 0)
|
|||
|
|
y = 1;
|
|||
|
|
|
|||
|
|
return htons ((x << 8) | (y & 0xff));
|
|||
|
|
|
|||
|
|
#undef x
|
|||
|
|
#undef y
|
|||
|
|
#undef c0
|
|||
|
|
#undef c1
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* Move the mods up + fix y */
|
|||
|
|
static u_int16_t
|
|||
|
|
reduce_isisd_mody (struct csum_vals *vals, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
#define x vals->x
|
|||
|
|
#define y vals->y
|
|||
|
|
#define c0 vals->a.c0
|
|||
|
|
#define c1 vals->a.c1
|
|||
|
|
u_int32_t mul;
|
|||
|
|
|
|||
|
|
mul = (len - off)*(c0);
|
|||
|
|
x = mul - c0 - c1;
|
|||
|
|
y = c1 - mul;
|
|||
|
|
|
|||
|
|
x %= 255;
|
|||
|
|
y %= 255;
|
|||
|
|
|
|||
|
|
if (y > 0)
|
|||
|
|
y++;
|
|||
|
|
if (x < 0)
|
|||
|
|
x--;
|
|||
|
|
|
|||
|
|
if (x == 0)
|
|||
|
|
x = 255;
|
|||
|
|
if (y == 0)
|
|||
|
|
y = 1;
|
|||
|
|
|
|||
|
|
return htons ((x << 8) | (y & 0xff));
|
|||
|
|
|
|||
|
|
#undef x
|
|||
|
|
#undef y
|
|||
|
|
#undef c0
|
|||
|
|
#undef c1
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
struct reductions_t {
|
|||
|
|
const char *name;
|
|||
|
|
u_int16_t (*f) (struct csum_vals *, testsz_t, testoff_t);
|
|||
|
|
} reducts[] = {
|
|||
|
|
{ .name = "ospfd", .f = reduce_ospfd },
|
|||
|
|
{ .name = "ospfd-1", .f = reduce_ospfd1 },
|
|||
|
|
{ .name = "isisd", .f = reduce_isisd },
|
|||
|
|
{ .name = "isisd-yfix", .f = reduce_isisd_yfix },
|
|||
|
|
{ .name = "isisd-mod", .f = reduce_isisd_mod },
|
|||
|
|
{ .name = "isisd-mody", .f = reduce_isisd_mody },
|
|||
|
|
{ NULL, NULL },
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
/* The original ospfd checksum */
|
|||
|
|
static u_int16_t
|
|||
|
|
ospfd_checksum (u_char *buffer, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
u_char *sp, *ep, *p, *q;
|
|||
|
|
int c0 = 0, c1 = 0;
|
|||
|
|
int x, y;
|
|||
|
|
u_int16_t checksum, *csum;
|
|||
|
|
|
|||
|
|
csum = (u_int16_t *) (buffer + off);
|
|||
|
|
*(csum) = 0;
|
|||
|
|
|
|||
|
|
sp = buffer;
|
|||
|
|
|
|||
|
|
for (ep = sp + len; sp < ep; sp = q)
|
|||
|
|
{
|
|||
|
|
q = sp + MODX;
|
|||
|
|
if (q > ep)
|
|||
|
|
q = ep;
|
|||
|
|
for (p = sp; p < q; p++)
|
|||
|
|
{
|
|||
|
|
c0 += *p;
|
|||
|
|
c1 += c0;
|
|||
|
|
}
|
|||
|
|
c0 %= 255;
|
|||
|
|
c1 %= 255;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
ospfd_vals.a.c0 = c0;
|
|||
|
|
ospfd_vals.a.c1 = c1;
|
|||
|
|
|
|||
|
|
//printf ("%s: len %u, off %u, c0 %d, c1 %d\n",
|
|||
|
|
// __func__, len, off, c0, c1);
|
|||
|
|
|
|||
|
|
x = ((int)(len - off - 1) * (int)c0 - (int)c1) % 255;
|
|||
|
|
|
|||
|
|
if (x <= 0)
|
|||
|
|
x += 255;
|
|||
|
|
y = 510 - c0 - x;
|
|||
|
|
if (y > 255)
|
|||
|
|
y -= 255;
|
|||
|
|
|
|||
|
|
ospfd_vals.x = x;
|
|||
|
|
ospfd_vals.y = y;
|
|||
|
|
|
|||
|
|
buffer[off] = x;
|
|||
|
|
buffer[off + 1] = y;
|
|||
|
|
|
|||
|
|
/* take care endian issue. */
|
|||
|
|
checksum = htons ((x << 8) | (y & 0xff));
|
|||
|
|
|
|||
|
|
return (checksum);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* the original, broken isisd checksum */
|
|||
|
|
static u_int16_t
|
|||
|
|
iso_csum_create (u_char * buffer, testsz_t len, testoff_t off)
|
|||
|
|
{
|
|||
|
|
|
|||
|
|
u_int8_t *p;
|
|||
|
|
int x;
|
|||
|
|
int y;
|
|||
|
|
u_int32_t mul;
|
|||
|
|
u_int32_t c0;
|
|||
|
|
u_int32_t c1;
|
|||
|
|
u_int16_t checksum, *csum;
|
|||
|
|
int i, init_len, partial_len;
|
|||
|
|
|
|||
|
|
checksum = 0;
|
|||
|
|
|
|||
|
|
csum = (u_int16_t *) (buffer + off);
|
|||
|
|
*(csum) = checksum;
|
|||
|
|
|
|||
|
|
p = buffer;
|
|||
|
|
c0 = 0;
|
|||
|
|
c1 = 0;
|
|||
|
|
init_len = len;
|
|||
|
|
|
|||
|
|
while (len != 0)
|
|||
|
|
{
|
|||
|
|
partial_len = MIN(len, MODX);
|
|||
|
|
|
|||
|
|
for (i = 0; i < partial_len; i++)
|
|||
|
|
{
|
|||
|
|
c0 = c0 + *(p++);
|
|||
|
|
c1 += c0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
c0 = c0 % 255;
|
|||
|
|
c1 = c1 % 255;
|
|||
|
|
|
|||
|
|
len -= partial_len;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
isisd_vals.a.c0 = c0;
|
|||
|
|
isisd_vals.a.c1 = c1;
|
|||
|
|
|
|||
|
|
mul = (init_len - off) * c0;
|
|||
|
|
|
|||
|
|
x = mul - c1 - c0;
|
|||
|
|
y = c1 - mul - 1;
|
|||
|
|
|
|||
|
|
if (y > 0)
|
|||
|
|
y++;
|
|||
|
|
if (x < 0)
|
|||
|
|
x--;
|
|||
|
|
|
|||
|
|
x %= 255;
|
|||
|
|
y %= 255;
|
|||
|
|
|
|||
|
|
if (x == 0)
|
|||
|
|
x = 255;
|
|||
|
|
if (y == 0)
|
|||
|
|
y = 1;
|
|||
|
|
|
|||
|
|
isisd_vals.x = x;
|
|||
|
|
isisd_vals.y = y;
|
|||
|
|
|
|||
|
|
checksum = htons((x << 8) | (y & 0xFF));
|
|||
|
|
|
|||
|
|
*(csum) = checksum;
|
|||
|
|
|
|||
|
|
/* return the checksum for user usage */
|
|||
|
|
return checksum;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
static int
|
|||
|
|
verify (u_char * buffer, testsz_t len)
|
|||
|
|
{
|
|||
|
|
u_int8_t *p;
|
|||
|
|
u_int32_t c0;
|
|||
|
|
u_int32_t c1;
|
|||
|
|
u_int16_t checksum;
|
|||
|
|
int i, partial_len;
|
|||
|
|
|
|||
|
|
p = buffer;
|
|||
|
|
checksum = 0;
|
|||
|
|
|
|||
|
|
c0 = 0;
|
|||
|
|
c1 = 0;
|
|||
|
|
|
|||
|
|
while (len)
|
|||
|
|
{
|
|||
|
|
partial_len = MIN(len, 5803);
|
|||
|
|
|
|||
|
|
for (i = 0; i < partial_len; i++)
|
|||
|
|
{
|
|||
|
|
c0 = c0 + *(p++);
|
|||
|
|
c1 += c0;
|
|||
|
|
}
|
|||
|
|
c0 = c0 % 255;
|
|||
|
|
c1 = c1 % 255;
|
|||
|
|
|
|||
|
|
len -= partial_len;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
if (c0 == 0 && c1 == 0)
|
|||
|
|
return 0;
|
|||
|
|
|
|||
|
|
return 1;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
int
|
|||
|
|
main(int argc, char **argv)
|
|||
|
|
{
|
|||
|
|
/* 60017 65629 702179 */
|
|||
|
|
#define MAXDATALEN 60017
|
|||
|
|
#define BUFSIZE MAXDATALEN + sizeof(u_int16_t)
|
|||
|
|
u_char buffer[BUFSIZE];
|
|||
|
|
int exercise = 0;
|
|||
|
|
#define EXERCISESTEP 257
|
|||
|
|
|
|||
|
|
srandom (time (NULL));
|
|||
|
|
|
|||
|
|
while (1) {
|
|||
|
|
u_int16_t ospfd, isisd, lib;
|
|||
|
|
|
|||
|
|
exercise += EXERCISESTEP;
|
|||
|
|
exercise %= MAXDATALEN;
|
|||
|
|
|
|||
|
|
for (int i = 0; i < exercise; i += sizeof (long int)) {
|
|||
|
|
long int rand = random ();
|
|||
|
|
|
|||
|
|
for (int j = sizeof (long int); j > 0; j--)
|
|||
|
|
buffer[i + (sizeof (long int) - j)] = (rand >> (j * 8)) & 0xff;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
ospfd = ospfd_checksum (buffer, exercise + sizeof(u_int16_t), exercise);
|
|||
|
|
if (verify (buffer, exercise + sizeof(u_int16_t)))
|
|||
|
|
printf ("verify: ospfd failed\n");
|
|||
|
|
isisd = iso_csum_create (buffer, exercise + sizeof(u_int16_t), exercise);
|
|||
|
|
if (verify (buffer, exercise + sizeof(u_int16_t)))
|
|||
|
|
printf ("verify: isisd failed\n");
|
|||
|
|
lib = fletcher_checksum (buffer, exercise + sizeof(u_int16_t), exercise);
|
|||
|
|
if (verify (buffer, exercise + sizeof(u_int16_t)))
|
|||
|
|
printf ("verify: lib failed\n");
|
|||
|
|
|
|||
|
|
if (ospfd != lib) {
|
|||
|
|
printf ("Mismatch in values at size %u\n"
|
|||
|
|
"ospfd: 0x%04x\tc0: %d\tc1: %d\tx: %d\ty: %d\n"
|
|||
|
|
"isisd: 0x%04x\tc0: %d\tc1: %d\tx: %d\ty: %d\n"
|
|||
|
|
"lib: 0x%04x\n",
|
|||
|
|
exercise,
|
|||
|
|
ospfd, ospfd_vals.a.c0, ospfd_vals.a.c1, ospfd_vals.x, ospfd_vals.y,
|
|||
|
|
isisd, isisd_vals.a.c0, isisd_vals.a.c1, isisd_vals.x, isisd_vals.y,
|
|||
|
|
lib
|
|||
|
|
);
|
|||
|
|
|
|||
|
|
/* Investigate reduction phase discrepencies */
|
|||
|
|
if (ospfd_vals.a.c0 == isisd_vals.a.c0
|
|||
|
|
&& ospfd_vals.a.c1 == isisd_vals.a.c1) {
|
|||
|
|
printf ("\n");
|
|||
|
|
for (int i = 0; reducts[i].name != NULL; i++) {
|
|||
|
|
ospfd = reducts[i].f (&ospfd_vals,
|
|||
|
|
exercise + sizeof (u_int16_t),
|
|||
|
|
exercise);
|
|||
|
|
printf ("%20s: x: %02x, y %02x, checksum 0x%04x\n",
|
|||
|
|
reducts[i].name, ospfd_vals.x & 0xff, ospfd_vals.y & 0xff, ospfd);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
printf ("\n u_char testdata [] = {\n ");
|
|||
|
|
for (int i = 0; i < exercise; i++) {
|
|||
|
|
printf ("0x%02x,%s",
|
|||
|
|
buffer[i],
|
|||
|
|
(i + 1) % 8 ? " " : "\n ");
|
|||
|
|
}
|
|||
|
|
printf ("\n}\n");
|
|||
|
|
exit (1);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|