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Move DHCP definitions into a common file

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These can be reused for other purposes than just the DHCP snoofing for
Proxy ARP. In addition, use more complete definition of the parameters
based on the current IANA registry.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen 2017-01-31 13:52:58 +02:00 • committed by Jouni Malinen
parent 70407ee5c3
commit e64c13febb
2 changed files with 263 additions and 30 deletions
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36
src/ap/dhcp_snoop.c
View file

@ -7,10 +7,9 @@
*/
#include "utils/includes.h"
#include <netinet/ip.h>
#include <netinet/udp.h>
#include "utils/common.h"
#include "common/dhcp.h"
#include "l2_packet/l2_packet.h"
#include "hostapd.h"
#include "sta_info.h"
@ -18,29 +17,6 @@
#include "x_snoop.h"
#include "dhcp_snoop.h"
struct bootp_pkt {
struct iphdr iph;
struct udphdr udph;
u8 op;
u8 htype;
u8 hlen;
u8 hops;
be32 xid;
be16 secs;
be16 flags;
be32 client_ip;
be32 your_ip;
be32 server_ip;
be32 relay_ip;
u8 hw_addr[16];
u8 serv_name[64];
u8 boot_file[128];
u8 exten[312];
} STRUCT_PACKED;
#define DHCPACK 5
static const u8 ic_bootp_cookie[] = { 99, 130, 83, 99 };
static const char * ipaddr_str(u32 addr)
{
@ -74,16 +50,16 @@ static void handle_dhcp(void *ctx, const u8 *src_addr, const u8 *buf,
if (tot_len > (unsigned int) (len - ETH_HLEN))
return;
if (os_memcmp(b->exten, ic_bootp_cookie, ARRAY_SIZE(ic_bootp_cookie)))
if (WPA_GET_BE32(b->exten) != DHCP_MAGIC)
return;
/* Parse DHCP options */
end = (const u8 *) b + tot_len;
pos = &b->exten[4];
while (pos < end && *pos != 0xff) {
while (pos < end && *pos != DHCP_OPT_END) {
const u8 *opt = pos++;
if (*opt == 0) /* padding */
if (*opt == DHCP_OPT_PAD)
continue;
pos += *pos + 1;
@ -91,7 +67,7 @@ static void handle_dhcp(void *ctx, const u8 *src_addr, const u8 *buf,
break;
switch (*opt) {
case 1: /* subnet mask */
case DHCP_OPT_SUBNET_MASK:
if (opt[1] == 4)
subnet_mask = WPA_GET_BE32(&opt[2]);
if (subnet_mask == 0)
@ -101,7 +77,7 @@ static void handle_dhcp(void *ctx, const u8 *src_addr, const u8 *buf,
prefixlen--;
}
break;
case 53: /* message type */
case DHCP_OPT_MSG_TYPE:
if (opt[1])
msgtype = opt[2];
break;