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

arp: Remove reply_offset, and keep previous ARP packet after epoll.

Browse Source 
ARP packets aren't split across multiple receive events, so
reply_offset is pointless, and we implicitly assume that the
previous ARP packet data is still available after a forced sleep.
This commit is contained in:
Nicholas J. Kain 2017-04-10 08:56:11 -04:00
parent bdad082a62
commit 7af3e64a99
3 changed files with 7 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/arp.c
View File

@ -70,7 +70,6 @@ static struct arp_data garp = {
.arp_check_start_ts = 0, .arp_check_start_ts = 0,
.total_conflicts = 0, .total_conflicts = 0,
.probe_wait_time = 0, .probe_wait_time = 0,
.reply_offset = 0,
.using_bpf = false, .using_bpf = false,
.relentless_def = false, .relentless_def = false,
.router_replied = false, .router_replied = false,
@ -79,10 +78,9 @@ 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; }
void arp_reply_clear(void) static void arp_reply_clear(void)
{ {
memset(&garp.reply, 0, sizeof garp.reply); memset(&garp.reply, 0, sizeof garp.reply);
garp.reply_offset = 0;
} }
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])
@ -745,9 +743,10 @@ 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])
{ {
ssize_t r = 0; ssize_t r = 0;
if (garp.reply_offset < sizeof garp.reply) { size_t bytes_read = 0;
r = safe_read(cs->arpFd, (char *)&garp.reply + garp.reply_offset, if (bytes_read < sizeof garp.reply) {
sizeof garp.reply - garp.reply_offset); r = safe_read(cs->arpFd, (char *)&garp.reply + bytes_read,
sizeof garp.reply - bytes_read);
if (r == 0) if (r == 0)
return false; return false;
if (r < 0) { if (r < 0) {
@ -760,10 +759,10 @@ bool arp_packet_get(struct client_state_t cs[static 1])
client_config.interface, __func__, strerror(errno)); client_config.interface, __func__, strerror(errno));
return false; return false;
} }
garp.reply_offset += (size_t)r; bytes_read += (size_t)r;
} }
if (garp.reply_offset < ARP_MSG_SIZE) if (bytes_read < ARP_MSG_SIZE)
return false; return false;
// Emulate the BPF filters if they are not in use. // Emulate the BPF filters if they are not in use.

2
src/arp.h
View File

@ -91,7 +91,6 @@ struct arp_data {
long long last_conflict_ts; // TS of the last conflicting ARP seen. long long last_conflict_ts; // TS of the last conflicting ARP seen.
long long arp_check_start_ts; // TS of when we started the long long arp_check_start_ts; // TS of when we started the
// AS_COLLISION_CHECK state. // AS_COLLISION_CHECK state.
size_t reply_offset;
unsigned int total_conflicts; // Total number of address conflicts on unsigned int total_conflicts; // Total number of address conflicts on
// the interface. Never decreases. // the interface. Never decreases.
int gw_check_initpings; // Initial count of ASEND_GW_PING when int gw_check_initpings; // Initial count of ASEND_GW_PING when
@ -104,7 +103,6 @@ struct arp_data {
bool server_replied:1; bool server_replied:1;
}; };
void arp_reply_clear(void);
void arp_reset_state(struct client_state_t cs[static 1]); void arp_reset_state(struct client_state_t cs[static 1]);
bool arp_packet_get(struct client_state_t cs[static 1]); bool arp_packet_get(struct client_state_t cs[static 1]);

2
src/ndhc.c
View File

@ -368,8 +368,6 @@ static void do_ndhc_work(void)
sev_arp, force_fingerprint, sev_arp, force_fingerprint,
cs.dhcp_wake_ts <= nowts, cs.dhcp_wake_ts <= nowts,
arp_wake_ts <= nowts, sev_signal); arp_wake_ts <= nowts, sev_signal);
if (sev_arp)
arp_reply_clear();
if (dhcp_ok == COR_ERROR) { if (dhcp_ok == COR_ERROR) {
timeout = 2000 + nk_random_u32(&cs.rnd32_state) % 3000; timeout = 2000 + nk_random_u32(&cs.rnd32_state) % 3000;