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[ipv4] Redefine IP address constants to avoid unnecessary byte swapping
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Redefine various IPv4 address constants and testing macros to avoid
unnecessary byte swapping at runtime, and slightly rename the macros
to prevent code from accidentally using the old definitions.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
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@mcb30
mcb30 committed Jul 28, 2015
1 parent 9c185e2 commit 6efcabd
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Showing 3 changed files with 44 additions and 37 deletions.
24 changes: 15 additions & 9 deletions src/include/ipxe/in.h
View file
Expand Up @@ -4,6 +4,7 @@
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <byteswap.h>
#include <ipxe/socket.h>

/* Protocol numbers */
Expand All @@ -15,17 +16,22 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

/* IP address constants */

#define INADDR_NONE 0xffffffff
#define INADDR_NONE htonl ( 0xffffffff )

#define INADDR_BROADCAST 0xffffffff
#define INADDR_BROADCAST htonl ( 0xffffffff )

#define IN_CLASSA(addr) ( ( (addr) & 0x80000000 ) == 0x00000000 )
#define IN_CLASSA_NET 0xff000000
#define IN_CLASSB(addr) ( ( (addr) & 0xc0000000 ) == 0x80000000 )
#define IN_CLASSB_NET 0xffff0000
#define IN_CLASSC(addr) ( ( (addr) & 0xe0000000 ) == 0xc0000000 )
#define IN_CLASSC_NET 0xffffff00
#define IN_MULTICAST(addr) ( ( (addr) & 0xf0000000 ) == 0xe0000000 )
#define INADDR_NET_CLASSA htonl ( 0xff000000 )
#define INADDR_NET_CLASSB htonl ( 0xffff0000 )
#define INADDR_NET_CLASSC htonl ( 0xffffff00 )

#define IN_IS_CLASSA( addr ) \
( ( (addr) & htonl ( 0x80000000 ) ) == htonl ( 0x00000000 ) )
#define IN_IS_CLASSB( addr ) \
( ( (addr) & htonl ( 0xc0000000 ) ) == htonl ( 0x80000000 ) )
#define IN_IS_CLASSC( addr ) \
( ( (addr) & htonl ( 0xe0000000 ) ) == htonl ( 0xc0000000 ) )
#define IN_IS_MULTICAST( addr ) \
( ( (addr) & htonl ( 0xf0000000 ) ) == htonl ( 0xe0000000 ) )

/**
* IP address structure
Expand Down
16 changes: 8 additions & 8 deletions src/net/ipv4.c
View file
Expand Up @@ -314,7 +314,7 @@ static int ipv4_tx ( struct io_buffer *iobuf,
if ( sin_src )
iphdr->src = sin_src->sin_addr;
if ( ( next_hop.s_addr != INADDR_BROADCAST ) &&
( ! IN_MULTICAST ( ntohl ( next_hop.s_addr ) ) ) &&
( ! IN_IS_MULTICAST ( next_hop.s_addr ) ) &&
( ( miniroute = ipv4_route ( &next_hop ) ) != NULL ) ) {
iphdr->src = miniroute->address;
netmask = miniroute->netmask;
Expand Down Expand Up @@ -353,7 +353,7 @@ static int ipv4_tx ( struct io_buffer *iobuf,
/* Broadcast address */
ipv4_stats.out_bcast_pkts++;
ll_dest = netdev->ll_broadcast;
} else if ( IN_MULTICAST ( ntohl ( next_hop.s_addr ) ) ) {
} else if ( IN_IS_MULTICAST ( next_hop.s_addr ) ) {
/* Multicast address */
ipv4_stats.out_mcast_pkts++;
if ( ( rc = netdev->ll_protocol->mc_hash ( AF_INET, &next_hop,
Expand Down Expand Up @@ -816,12 +816,12 @@ static int ipv4_create_routes ( void ) {
fetch_ipv4_setting ( settings, &netmask_setting, &netmask );
/* Calculate default netmask, if necessary */
if ( ! netmask.s_addr ) {
if ( IN_CLASSA ( ntohl ( address.s_addr ) ) ) {
netmask.s_addr = htonl ( IN_CLASSA_NET );
} else if ( IN_CLASSB ( ntohl ( address.s_addr ) ) ) {
netmask.s_addr = htonl ( IN_CLASSB_NET );
} else if ( IN_CLASSC ( ntohl ( address.s_addr ) ) ) {
netmask.s_addr = htonl ( IN_CLASSC_NET );
if ( IN_IS_CLASSA ( address.s_addr ) ) {
netmask.s_addr = INADDR_NET_CLASSA;
} else if ( IN_IS_CLASSB ( address.s_addr ) ) {
netmask.s_addr = INADDR_NET_CLASSB;
} else if ( IN_IS_CLASSC ( address.s_addr ) ) {
netmask.s_addr = INADDR_NET_CLASSC;
}
}
/* Get default gateway, if present */
Expand Down
41 changes: 21 additions & 20 deletions src/tests/ipv4_test.c
View file
Expand Up @@ -39,7 +39,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <ipxe/test.h>

/** Define inline IPv4 address */
#define IPV4(a,b,c,d) ( ( (a) << 24 ) | ( (b) << 16 ) | ( (c) << 8 ) | (d) )
#define IPV4(a,b,c,d) \
htonl ( ( (a) << 24 ) | ( (b) << 16 ) | ( (c) << 8 ) | (d) )

/**
* Report an inet_ntoa() test result
Expand All @@ -51,7 +52,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
*/
static void inet_ntoa_okx ( uint32_t addr, const char *text, const char *file,
unsigned int line ) {
struct in_addr in = { .s_addr = htonl ( addr ) };
struct in_addr in = { .s_addr = addr };
char *actual;

/* Format address */
Expand Down Expand Up @@ -81,7 +82,7 @@ static void inet_aton_okx ( const char *text, uint32_t addr, const char *file,
/* Parse address */
okx ( inet_aton ( text, &actual ) != 0, file, line );
DBG ( "inet_aton ( \"%s\" ) = %s\n", text, inet_ntoa ( actual ) );
okx ( ntohl ( actual.s_addr ) == addr, file, line );
okx ( actual.s_addr == addr, file, line );
};
#define inet_aton_ok( text, addr ) \
inet_aton_okx ( text, addr, __FILE__, __LINE__ )
Expand Down Expand Up @@ -110,23 +111,23 @@ static void inet_aton_fail_okx ( const char *text, const char *file,
static void ipv4_test_exec ( void ) {

/* Address testing macros */
ok ( IN_CLASSA ( IPV4 ( 10, 0, 0, 1 ) ) );
ok ( ! IN_CLASSB ( IPV4 ( 10, 0, 0, 1 ) ) );
ok ( ! IN_CLASSC ( IPV4 ( 10, 0, 0, 1 ) ) );
ok ( ! IN_CLASSA ( IPV4 ( 172, 16, 0, 1 ) ) );
ok ( IN_CLASSB ( IPV4 ( 172, 16, 0, 1 ) ) );
ok ( ! IN_CLASSC ( IPV4 ( 172, 16, 0, 1 ) ) );
ok ( ! IN_CLASSA ( IPV4 ( 192, 168, 0, 1 ) ) );
ok ( ! IN_CLASSB ( IPV4 ( 192, 168, 0, 1 ) ) );
ok ( IN_CLASSC ( IPV4 ( 192, 168, 0, 1 ) ) );
ok ( ! IN_MULTICAST ( IPV4 ( 127, 0, 0, 1 ) ) );
ok ( ! IN_MULTICAST ( IPV4 ( 8, 8, 8, 8 ) ) );
ok ( ! IN_MULTICAST ( IPV4 ( 0, 0, 0, 0 ) ) );
ok ( ! IN_MULTICAST ( IPV4 ( 223, 0, 0, 1 ) ) );
ok ( ! IN_MULTICAST ( IPV4 ( 240, 0, 0, 1 ) ) );
ok ( IN_MULTICAST ( IPV4 ( 224, 0, 0, 1 ) ) );
ok ( IN_MULTICAST ( IPV4 ( 231, 89, 0, 2 ) ) );
ok ( IN_MULTICAST ( IPV4 ( 239, 6, 1, 17 ) ) );
ok ( IN_IS_CLASSA ( IPV4 ( 10, 0, 0, 1 ) ) );
ok ( ! IN_IS_CLASSB ( IPV4 ( 10, 0, 0, 1 ) ) );
ok ( ! IN_IS_CLASSC ( IPV4 ( 10, 0, 0, 1 ) ) );
ok ( ! IN_IS_CLASSA ( IPV4 ( 172, 16, 0, 1 ) ) );
ok ( IN_IS_CLASSB ( IPV4 ( 172, 16, 0, 1 ) ) );
ok ( ! IN_IS_CLASSC ( IPV4 ( 172, 16, 0, 1 ) ) );
ok ( ! IN_IS_CLASSA ( IPV4 ( 192, 168, 0, 1 ) ) );
ok ( ! IN_IS_CLASSB ( IPV4 ( 192, 168, 0, 1 ) ) );
ok ( IN_IS_CLASSC ( IPV4 ( 192, 168, 0, 1 ) ) );
ok ( ! IN_IS_MULTICAST ( IPV4 ( 127, 0, 0, 1 ) ) );
ok ( ! IN_IS_MULTICAST ( IPV4 ( 8, 8, 8, 8 ) ) );
ok ( ! IN_IS_MULTICAST ( IPV4 ( 0, 0, 0, 0 ) ) );
ok ( ! IN_IS_MULTICAST ( IPV4 ( 223, 0, 0, 1 ) ) );
ok ( ! IN_IS_MULTICAST ( IPV4 ( 240, 0, 0, 1 ) ) );
ok ( IN_IS_MULTICAST ( IPV4 ( 224, 0, 0, 1 ) ) );
ok ( IN_IS_MULTICAST ( IPV4 ( 231, 89, 0, 2 ) ) );
ok ( IN_IS_MULTICAST ( IPV4 ( 239, 6, 1, 17 ) ) );

/* inet_ntoa() tests */
inet_ntoa_ok ( IPV4 ( 127, 0, 0, 1 ), "127.0.0.1" );
Expand Down

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