udhcpc[6]: do not pass xid around, keep it in client_data.xid
function old new delta
perform_release 105 169 +64
perform_d6_release 259 262 +3
init_d6_packet 84 85 +1
send_d6_discover 286 285 -1
send_d6_select 128 126 -2
send_d6_renew 176 174 -2
send_d6_info_request 65 63 -2
udhcpc_main 2555 2551 -4
send_select 130 122 -8
send_renew 99 91 -8
send_discover 89 81 -8
udhcpc6_main 2636 2602 -34
send_release 74 - -74
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 3/9 up/down: 68/-143) Total: -75 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index b80ea2f..1c3c478 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -605,7 +605,7 @@
/* Fill in: op, htype, hlen, cookie fields; message type option: */
udhcp_init_header(packet, type);
- packet->xid = random_xid();
+ packet->xid = client_data.xid;
client_data.last_secs = monotonic_sec();
if (client_data.first_secs == 0)
@@ -719,17 +719,15 @@
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
/* NOINLINE: limit stack usage in caller */
-static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
+static NOINLINE int send_discover(uint32_t requested)
{
struct dhcp_packet packet;
/* Fill in: op, htype, hlen, cookie, chaddr fields,
- * random xid field (we override it below),
- * message type option:
+ * xid field, message type option:
*/
init_packet(&packet, DHCPDISCOVER);
- packet.xid = xid;
if (requested)
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
@@ -747,7 +745,7 @@
* "The client _broadcasts_ a DHCPREQUEST message..."
*/
/* NOINLINE: limit stack usage in caller */
-static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
+static NOINLINE int send_select(uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
struct in_addr temp_addr;
@@ -766,12 +764,10 @@
* include that list in all subsequent messages.
*/
/* Fill in: op, htype, hlen, cookie, chaddr fields,
- * random xid field (we override it below),
- * message type option:
+ * xid field, message type option:
*/
init_packet(&packet, DHCPREQUEST);
- packet.xid = xid;
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
@@ -793,7 +789,7 @@
/* Unicast or broadcast a DHCP renew message */
/* NOINLINE: limit stack usage in caller */
-static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
+static NOINLINE int send_renew(uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
@@ -812,12 +808,10 @@
* replying to the client.
*/
/* Fill in: op, htype, hlen, cookie, chaddr fields,
- * random xid field (we override it below),
- * message type option:
+ * xid field, message type option:
*/
init_packet(&packet, DHCPREQUEST);
- packet.xid = xid;
packet.ciaddr = ciaddr;
/* Add options: maxsize,
@@ -839,7 +833,7 @@
#if ENABLE_FEATURE_UDHCPC_ARPING
/* Broadcast a DHCP decline message */
/* NOINLINE: limit stack usage in caller */
-static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested)
+static NOINLINE int send_decline(uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
@@ -848,14 +842,6 @@
*/
init_packet(&packet, DHCPDECLINE);
-#if 0
- /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
- * but in case the server is buggy and wants DHCPDECLINE's xid
- * to match the xid which started entire handshake,
- * we use the same xid we used in initial DHCPDISCOVER:
- */
- packet.xid = xid;
-#endif
/* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
@@ -1145,6 +1131,7 @@
temp_addr.s_addr = requested_ip;
bb_info_msg("unicasting a release of %s to %s",
inet_ntoa(temp_addr), buffer);
+ client_data.xid = random_xid(); //TODO: can omit?
send_release(server_addr, requested_ip); /* unicast */
}
bb_simple_info_msg("entering released state");
@@ -1233,7 +1220,6 @@
int discover_retries = 3;
uint32_t server_addr = server_addr; /* for compiler */
uint32_t requested_ip = 0;
- uint32_t xid = xid; /* for compiler */
int packet_num;
int timeout; /* must be signed */
int lease_remaining; /* must be signed */
@@ -1458,10 +1444,10 @@
if (!discover_retries || packet_num < discover_retries) {
if (packet_num == 0) {
change_listen_mode(LISTEN_RAW);
- xid = random_xid();
+ client_data.xid = random_xid();
}
/* broadcast */
- send_discover(xid, requested_ip);
+ send_discover(requested_ip);
timeout = discover_timeout;
packet_num++;
continue;
@@ -1495,7 +1481,7 @@
case REQUESTING:
if (packet_num < 3) {
/* send broadcast select packet */
- send_select(xid, server_addr, requested_ip);
+ send_select(server_addr, requested_ip);
timeout = discover_timeout;
packet_num++;
continue;
@@ -1526,7 +1512,7 @@
* Anyway, it does recover by eventually failing through
* into INIT_SELECTING state.
*/
- if (send_renew(xid, server_addr, requested_ip) >= 0) {
+ if (send_renew(server_addr, requested_ip) >= 0) {
timeout = discover_timeout;
packet_num++;
continue;
@@ -1555,7 +1541,7 @@
* try to find DHCP server using broadcast */
if (lease_remaining > 0 && packet_num < 3) {
/* send a broadcast renew request */
- send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
+ send_renew(0 /*INADDR_ANY*/, requested_ip);
timeout = discover_timeout;
packet_num++;
continue;
@@ -1648,9 +1634,9 @@
continue;
}
- if (packet.xid != xid) {
+ if (packet.xid != client_data.xid) {
log1("xid %x (our is %x)%s",
- (unsigned)packet.xid, (unsigned)xid,
+ (unsigned)packet.xid, (unsigned)client_data.xid,
", ignoring packet"
);
continue;
@@ -1779,7 +1765,8 @@
) {
bb_simple_info_msg("offered address is in use "
"(got ARP reply), declining");
- send_decline(/*xid,*/ server_addr, packet.yiaddr);
+ client_data.xid = random_xid(); //TODO: can omit?
+ send_decline(server_addr, packet.yiaddr);
if (client_data.state != REQUESTING)
d4_run_script_deconfig();
@@ -1814,7 +1801,7 @@
timeout = (unsigned)lease_remaining / 2;
client_data.state = BOUND;
/* make future renew packets use different xid */
- /* xid = random_xid(); ...but why bother? */
+ /* client_data.xid = random_xid(); ...but why bother? */
packet_num = 0;
continue; /* back to main loop */
}