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udhcpc[6]: do not pass xid around, keep it in client_data.xid

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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>
This commit is contained in:
Denys Vlasenko
2021-06-15 01:02:01 +02:00
parent 40a327aeae
commit 827b690fa7
3 changed files with 48 additions and 60 deletions
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51
networking/udhcp/dhcpc.c
View File

@ -605,7 +605,7 @@ static void init_packet(struct dhcp_packet *packet, char type)
/* 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 @@ static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t
/* 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 @@ static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
* "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 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste
* 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 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste
/* 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 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
* 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 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
#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 @@ static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t req
*/
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 @@ static void perform_release(uint32_t server_addr, uint32_t requested_ip)
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 udhcpc_main(int argc UNUSED_PARAM, char **argv)
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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
* 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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
* 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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
) {
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 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
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 */
}