From: Denis Ovsienko <denis@ovsienko.info>
Date: Sat, 14 Jan 2023 22:25:18 +0000 (+0000)
Subject: Remove init_crc10_table() and the entourage.
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/94f232c1ab0143c6da9fc00732b6b241b8abdf4c

Remove init_crc10_table() and the entourage.

As Guy Harris points out in bug report GH #1022, the function has been a
busy no-op since commit e6c39e6 in 2010.  While at it, fixup the Python
code to work on Python 3:

    for i in range(len(crc_table)/8):
TypeError: 'float' object cannot be interpreted as an integer
---

diff --git a/checksum.c b/checksum.c
index e6e84a25..c5025082 100644
--- a/checksum.c
+++ b/checksum.c
@@ -44,7 +44,7 @@ for i in range(256):
 			accum ^= 0x633
 	crc_table.append(accum)
 
-for i in range(len(crc_table)/8):
+for i in range(int(len(crc_table)/8)):
 	for j in range(8):
 		sys.stdout.write("0x%04x, " % crc_table[i*8+j])
 	sys.stdout.write("\n")
@@ -86,29 +86,6 @@ static const uint16_t crc10_table[256] =
 	0x021e, 0x002d, 0x004b, 0x0278, 0x0087, 0x02b4, 0x02d2, 0x00e1
 };
 
-static void
-init_crc10_table(void)
-{
-#define CRC10_POLYNOMIAL 0x633
-    int i, j;
-    uint16_t accum;
-    uint16_t verify_crc10_table[256];
-
-    for ( i = 0;  i < 256;  i++ )
-    {
-        accum = ((unsigned short) i << 2);
-        for ( j = 0;  j < 8;  j++ )
-        {
-            if ((accum <<= 1) & 0x400) accum ^= CRC10_POLYNOMIAL;
-        }
-        verify_crc10_table[i] = accum;
-    }
-    assert(memcmp(verify_crc10_table,
-				  crc10_table,
-				  sizeof(verify_crc10_table)) == 0);
-#undef CRC10_POLYNOMIAL
-}
-
 uint16_t
 verify_crc10_cksum(uint16_t accum, const u_char *p, int length)
 {
@@ -123,14 +100,6 @@ verify_crc10_cksum(uint16_t accum, const u_char *p, int length)
     return accum;
 }
 
-/* precompute checksum tables */
-void
-init_checksum(void) {
-
-    init_crc10_table();
-
-}
-
 /*
  * Creates the OSI Fletcher checksum. See 8473-1, Appendix C, section C.3.
  * The checksum field of the passed PDU does not need to be reset to zero.
diff --git a/netdissect.h b/netdissect.h
index 24fda9e8..5762c584 100644
--- a/netdissect.h
+++ b/netdissect.h
@@ -764,7 +764,6 @@ extern void zmtp1_datagram_print(netdissect_options *, const u_char *, const u_i
 extern void zmtp1_print(netdissect_options *, const u_char *, u_int);
 
 /* checksum routines */
-extern void init_checksum(void);
 extern uint16_t verify_crc10_cksum(uint16_t, const u_char *, int);
 extern uint16_t create_osi_cksum(const uint8_t *, int, int);
 
diff --git a/print.c b/print.c
index fbb1b3b1..123c842c 100644
--- a/print.c
+++ b/print.c
@@ -249,9 +249,7 @@ static const struct printer printers[] = {
 void
 init_print(netdissect_options *ndo, uint32_t localnet, uint32_t mask)
 {
-
 	init_addrtoname(ndo, localnet, mask);
-	init_checksum();
 }
 
 if_printer