osmith
/
wireshark
forked from osmocom/wireshark
1
0
Fork 0
Code Pull Requests Releases Wiki Activity

addr_resolv: add fast path for parsing addresses from manuf 

The manuf file is large but has a consistent format (25.7k entries with
three octets, 9.8k entries with a mask). Add a fast path for this file
that is 20% faster (saves 20ms on an unoptimized Debug+ASAN build).

Change-Id: Ida509b0305caf4e26131dc5cf5fb04c49392ad4b
Reviewed-on: https://code.wireshark.org/review/30757
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
This commit is contained in:
Peter Wu 2018-11-21 21:08:02 +01:00 committed by Anders Broman
parent ada5b88647
commit 3bb32ede26
1 changed files with 100 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

102
epan/addr_resolv.c
View File

@ -1131,6 +1131,100 @@ host_lookup6(const ws_in6_addr *addr)
* -- Laurent.
*/
/*
* Converts Ethernet addresses of the form aa:bb:cc or aa:bb:cc:dd:ee:ff/28. The
* octets must be exactly two hexadecimal characters and the mask must be either
* 28 or 36. Pre-condition: cp MUST be at least 21 bytes.
*/
static gboolean
parse_ether_address_fast(const char *cp, ether_t *eth, unsigned int *mask,
const gboolean accept_mask)
{
/* XXX copied from strutil.c */
/* a map from ASCII hex chars to their value */
static const gint8 str_to_nibble[256] = {
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1,
-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
};
if (cp[2] != ':' || cp[5] != ':') {
/* Unexpected separators. */
return FALSE;
}
int num0 = (str_to_nibble[(int)cp[0]] << 8) | str_to_nibble[(int)cp[1]];
int num1 = (str_to_nibble[(int)cp[3]] << 8) | str_to_nibble[(int)cp[4]];
int num2 = (str_to_nibble[(int)cp[6]] << 8) | str_to_nibble[(int)cp[7]];
if ((num0 | num1 | num2) < 0) {
/* Not hexadecimal numbers. */
return FALSE;
}
eth->addr[0] = num0;
eth->addr[1] = num1;
eth->addr[2] = num2;
if (cp[8] == '\0' && accept_mask) {
/* Indicate that this is a manufacturer ID (0 is not allowed as a mask). */
*mask = 0;
return TRUE;
} else if (cp[8] != ':') {
/* Format not handled by this fast path. */
return FALSE;
}
int num3 = (str_to_nibble[(int)cp[9]] << 8) | str_to_nibble[(int)cp[10]];
int num4 = (str_to_nibble[(int)cp[12]] << 8) | str_to_nibble[(int)cp[13]];
int num5 = (str_to_nibble[(int)cp[15]] << 8) | str_to_nibble[(int)cp[16]];
if ((num3 | num4 | num5) < 0 || cp[11] != ':' || cp[14] != ':') {
/* Not hexadecimal numbers or invalid separators. */
return FALSE;
}
eth->addr[3] = num3;
eth->addr[4] = num4;
eth->addr[5] = num5;
if (cp[17] == '\0') {
/* We got 6 bytes, so this is a MAC address (48 is not allowed as a mask). */
*mask = 48;
return TRUE;
} else if (cp[17] != '/' || cp[20] != '\0') {
/* Format not handled by this fast path. */
return FALSE;
}
int m1 = cp[18];
int m2 = cp[19];
if (m1 == '3' && m2 == '6') { /* Mask /36 */
eth->addr[4] &= 0xf0;
eth->addr[5] = 0;
*mask = 36;
return TRUE;
}
if (m1 == '2' && m2 == '8') { /* Mask /28 */
eth->addr[3] &= 0xf0;
eth->addr[4] = 0;
eth->addr[5] = 0;
*mask = 28;
return TRUE;
}
/* Unsupported mask */
return FALSE;
}
/*
* If "accept_mask" is FALSE, cp must point to an address that consists
@ -1257,8 +1351,12 @@ parse_ether_line(char *line, ether_t *eth, unsigned int *mask,
if ((cp = strtok(line, " \t")) == NULL)
return -1;
if (!parse_ether_address(cp, eth, mask, accept_mask))
return -1;
/* First try to match the common format for the large ethers file. */
if (!parse_ether_address_fast(cp, eth, mask, accept_mask)) {
/* Fallback for the well-known addresses (wka) file. */
if (!parse_ether_address(cp, eth, mask, accept_mask))
return -1;
}
if ((cp = strtok(NULL, " \t")) == NULL)
return -1;