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

udhcpc: shrink code by setting xid more economically

Browse Source 
function                                             old     new   delta
send_decline                                          90      82      -8
udhcpc_main                                         2649    2640      -9

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2011-11-18 02:09:13 +01:00
parent 1dc80bae0b
commit 860491c525
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
networking/udhcp/dhcpc.c
View File

@ -726,7 +726,7 @@ 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 xid,*/ uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
@ -735,12 +735,14 @@ static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t request
*/
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);
@ -1131,7 +1133,7 @@ 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 = 0;
uint32_t xid = xid; /* for compiler */
int packet_num;
int timeout; /* must be signed */
unsigned already_waited_sec;
@ -1520,7 +1522,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
switch (state) {
case INIT_SELECTING:
/* Must be a DHCPOFFER to one of our xid's */
/* Must be a DHCPOFFER */
if (*message == DHCPOFFER) {
/* What exactly is server's IP? There are several values.
* Example DHCP offer captured with tchdump:
@ -1600,7 +1602,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
) {
bb_info_msg("Offered address is in use "
"(got ARP reply), declining");
send_decline(xid, server_addr, packet.yiaddr);
send_decline(/*xid,*/ server_addr, packet.yiaddr);
if (state != REQUESTING)
udhcp_run_script(NULL, "deconfig");
@ -1637,6 +1639,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
opt = ((opt & ~OPT_b) | OPT_f);
}
#endif
/* make future renew packets use different xid */
/* xid = random_xid(); ...but why bother? */
already_waited_sec = 0;
continue; /* back to main loop */
}