emo/ndhc
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

arp: Take extra care to preserve last received ARP packet.

Browse Source
This commit is contained in:
Nicholas J. Kain 2017-04-10 09:29:36 -04:00
parent 7af3e64a99
commit 369ff59cab
1 changed files with 8 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
src/arp.c
View File

@ -78,11 +78,6 @@ static struct arp_data garp = {
void set_arp_relentless_def(bool v) { garp.relentless_def = v; } void set_arp_relentless_def(bool v) { garp.relentless_def = v; }
static void arp_reply_clear(void)
{
memset(&garp.reply, 0, sizeof garp.reply);
}
static void arp_min_close_fd(struct client_state_t cs[static 1]) static void arp_min_close_fd(struct client_state_t cs[static 1])
{ {
if (cs->arpFd < 0) if (cs->arpFd < 0)
@ -103,7 +98,7 @@ static void arp_close_fd(struct client_state_t cs[static 1])
void arp_reset_state(struct client_state_t cs[static 1]) void arp_reset_state(struct client_state_t cs[static 1])
{ {
arp_close_fd(cs); arp_close_fd(cs);
arp_reply_clear(); memset(&garp.reply, 0, sizeof garp.reply);
garp.last_conflict_ts = 0; garp.last_conflict_ts = 0;
garp.gw_check_initpings = 0; garp.gw_check_initpings = 0;
garp.arp_check_start_ts = 0; garp.arp_check_start_ts = 0;
@ -166,7 +161,6 @@ static int arp_open_fd(struct client_state_t cs[static 1], bool defense)
return -1; return -1;
} }
epoll_add(cs->epollFd, cs->arpFd); epoll_add(cs->epollFd, cs->arpFd);
arp_reply_clear();
return 0; return 0;
} }
@ -742,11 +736,12 @@ server_is_router:
bool arp_packet_get(struct client_state_t cs[static 1]) bool arp_packet_get(struct client_state_t cs[static 1])
{ {
struct arpMsg amsg;
ssize_t r = 0; ssize_t r = 0;
size_t bytes_read = 0; size_t bytes_read = 0;
if (bytes_read < sizeof garp.reply) { if (bytes_read < sizeof amsg) {
r = safe_read(cs->arpFd, (char *)&garp.reply + bytes_read, r = safe_read(cs->arpFd, (char *)&amsg + bytes_read,
sizeof garp.reply - bytes_read); sizeof amsg - bytes_read);
if (r == 0) if (r == 0)
return false; return false;
if (r < 0) { if (r < 0) {
@ -767,12 +762,12 @@ bool arp_packet_get(struct client_state_t cs[static 1])
// Emulate the BPF filters if they are not in use. // Emulate the BPF filters if they are not in use.
if (!garp.using_bpf && if (!garp.using_bpf &&
(!arp_validate_bpf(&garp.reply) || (!arp_validate_bpf(&amsg) ||
(cs->arp_is_defense && (cs->arp_is_defense &&
!arp_validate_bpf_defense(cs, &garp.reply)))) { !arp_validate_bpf_defense(cs, &amsg)))) {
arp_reply_clear();
return false; return false;
} }
memcpy(&garp.reply, &amsg, sizeof garp.reply);
return true; return true;
} }