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-rw-r--r--tests/lib/test_checksum.c572
1 files changed, 572 insertions, 0 deletions
diff --git a/tests/lib/test_checksum.c b/tests/lib/test_checksum.c
new file mode 100644
index 0000000..329ae60
--- /dev/null
+++ b/tests/lib/test_checksum.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2008 Sun Microsystems, Inc.
+ */
+
+#include <zebra.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "checksum.h"
+#include "network.h"
+#include "prng.h"
+
+struct event_loop *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 4102U
+
+/* The final reduction phase.
+ * This one should be the original ospfd version
+ */
+static uint16_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 uint16_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 uint16_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
+ uint32_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 uint16_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
+ uint32_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 uint16_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
+ uint32_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 uint16_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
+ uint32_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;
+ uint16_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 uint16_t ospfd_checksum(uint8_t *buffer, testsz_t len, testoff_t off)
+{
+ uint8_t *sp, *ep, *p, *q;
+ int c0 = 0, c1 = 0;
+ int x, y;
+ uint16_t checksum, *csum;
+
+ csum = (uint16_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 uint16_t iso_csum_create(uint8_t *buffer, testsz_t len, testoff_t off)
+{
+
+ uint8_t *p;
+ int x;
+ int y;
+ uint32_t mul;
+ uint32_t c0;
+ uint32_t c1;
+ uint16_t checksum, *csum;
+ int i, init_len, partial_len;
+
+ checksum = 0;
+
+ csum = (uint16_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(uint8_t *buffer, testsz_t len)
+{
+ uint8_t *p;
+ uint32_t c0;
+ uint32_t c1;
+ int i, partial_len;
+
+ p = buffer;
+
+ c0 = 0;
+ c1 = 0;
+
+ while (len) {
+ partial_len = MIN(len, 5803U);
+
+ 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;
+}
+
+static int /* return checksum in low-order 16 bits */
+ in_cksum_optimized(void *parg, int nbytes)
+{
+ unsigned short *ptr = parg;
+ register long sum; /* assumes long == 32 bits */
+ register unsigned short answer; /* assumes unsigned short == 16 bits */
+ register int count;
+ /*
+ * Our algorithm is simple, using a 32-bit accumulator (sum),
+ * we add sequential 16-bit words to it, and at the end, fold back
+ * all the carry bits from the top 16 bits into the lower 16 bits.
+ */
+
+ sum = 0;
+ count = nbytes >> 1; /* div by 2 */
+ for (ptr--; count; --count)
+ sum += *++ptr;
+
+ if (nbytes & 1) /* Odd */
+ sum += *(uint8_t *)(++ptr); /* one byte only */
+
+ /*
+ * Add back carry outs from top 16 bits to low 16 bits.
+ */
+
+ sum = (sum >> 16) + (sum & 0xffff); /* add high-16 to low-16 */
+ sum += (sum >> 16); /* add carry */
+ answer = ~sum; /* ones-complement, then truncate to 16 bits */
+ return (answer);
+}
+
+
+static int /* return checksum in low-order 16 bits */
+ in_cksum_rfc(void *parg, int count)
+/* from RFC 1071 */
+{
+ unsigned short *addr = parg;
+ /* Compute Internet Checksum for "count" bytes
+ * beginning at location "addr".
+ */
+ register long sum = 0;
+
+ while (count > 1) {
+ /* This is the inner loop */
+ sum += *addr++;
+ count -= 2;
+ }
+ /* Add left-over byte, if any */
+ if (count > 0) {
+ sum += *(uint8_t *)addr;
+ }
+
+ /* Fold 32-bit sum to 16 bits */
+ while (sum >> 16)
+ sum = (sum & 0xffff) + (sum >> 16);
+ return ~sum;
+}
+
+
+int main(int argc, char **argv)
+{
+/* 60017 65629 702179 */
+#define MAXDATALEN 60017
+#define BUFSIZE MAXDATALEN + sizeof(uint16_t)
+ uint8_t buffer[BUFSIZE];
+ int exercise = 0;
+#define EXERCISESTEP 257
+ struct prng *prng = prng_new(0);
+
+ while (1) {
+ uint16_t ospfd, isisd, lib, in_csum, in_csum_res, in_csum_rfc;
+ int i;
+
+ exercise += EXERCISESTEP;
+ exercise %= MAXDATALEN;
+
+ printf("\rexercising length %d\033[K", exercise);
+
+ for (i = 0; i < exercise; i++)
+ buffer[i] = prng_rand(prng);
+
+ in_csum = in_cksum(buffer, exercise);
+ in_csum_res = in_cksum_optimized(buffer, exercise);
+ in_csum_rfc = in_cksum_rfc(buffer, exercise);
+ if (in_csum_res != in_csum || in_csum != in_csum_rfc)
+ printf("\nverify: in_chksum failed in_csum:%x, in_csum_res:%x,in_csum_rfc %x, len:%d\n",
+ in_csum, in_csum_res, in_csum_rfc, exercise);
+
+ struct iovec iov[3];
+ uint16_t in_csum_iov;
+
+ iov[0].iov_base = buffer;
+ iov[0].iov_len = exercise / 2;
+ iov[1].iov_base = buffer + iov[0].iov_len;
+ iov[1].iov_len = exercise - iov[0].iov_len;
+
+ in_csum_iov = in_cksumv(iov, 2);
+ if (in_csum_iov != in_csum)
+ printf("\nverify: in_cksumv failed, lens: %zu+%zu\n",
+ iov[0].iov_len, iov[1].iov_len);
+
+ if (exercise >= 6) {
+ /* force split with byte leftover */
+ iov[0].iov_base = buffer;
+ iov[0].iov_len = (exercise / 2) | 1;
+ iov[1].iov_base = buffer + iov[0].iov_len;
+ iov[1].iov_len = 2;
+ iov[2].iov_base = buffer + iov[0].iov_len + 2;
+ iov[2].iov_len = exercise - iov[0].iov_len - 2;
+
+ in_csum_iov = in_cksumv(iov, 3);
+ if (in_csum_iov != in_csum)
+ printf("\nverify: in_cksumv failed, lens: %zu+%zu+%zu, got %04x, expected %04x\n",
+ iov[0].iov_len, iov[1].iov_len,
+ iov[2].iov_len, in_csum_iov, in_csum);
+
+ /* force split without byte leftover */
+ iov[0].iov_base = buffer;
+ iov[0].iov_len = (exercise / 2) & ~1UL;
+ iov[1].iov_base = buffer + iov[0].iov_len;
+ iov[1].iov_len = 2;
+ iov[2].iov_base = buffer + iov[0].iov_len + 2;
+ iov[2].iov_len = exercise - iov[0].iov_len - 2;
+
+ in_csum_iov = in_cksumv(iov, 3);
+ if (in_csum_iov != in_csum)
+ printf("\nverify: in_cksumv failed, lens: %zu+%zu+%zu, got %04x, expected %04x\n",
+ iov[0].iov_len, iov[1].iov_len,
+ iov[2].iov_len, in_csum_iov, in_csum);
+ }
+
+ if (exercise >= FLETCHER_CHECKSUM_VALIDATE)
+ continue;
+
+ ospfd = ospfd_checksum(buffer, exercise + sizeof(uint16_t),
+ exercise);
+ if (verify(buffer, exercise + sizeof(uint16_t)))
+ printf("\nverify: ospfd failed\n");
+ isisd = iso_csum_create(buffer, exercise + sizeof(uint16_t),
+ exercise);
+ if (verify(buffer, exercise + sizeof(uint16_t)))
+ printf("\nverify: isisd failed\n");
+ lib = fletcher_checksum(buffer, exercise + sizeof(uint16_t),
+ exercise);
+ if (verify(buffer, exercise + sizeof(uint16_t)))
+ printf("\nverify: lib failed\n");
+
+ if (ospfd != lib) {
+ printf("\nMismatch in values at size %d\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 (i = 0; reducts[i].name != NULL; i++) {
+ ospfd = reducts[i].f(
+ &ospfd_vals,
+ exercise + sizeof(uint16_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 uint8_t testdata [] = {\n ");
+ for (i = 0; i < exercise; i++) {
+ printf("0x%02x,%s", buffer[i],
+ (i + 1) % 8 ? " " : "\n ");
+ }
+ printf("\n}\n");
+ exit(1);
+ }
+ }
+}
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