From 860491c5251886c40d6dfb89723f392db3a397a9 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 18 Nov 2011 02:09:13 +0100 Subject: [PATCH] udhcpc: shrink code by setting xid more economically function old new delta send_decline 90 82 -8 udhcpc_main 2649 2640 -9 Signed-off-by: Denys Vlasenko --- networking/udhcp/dhcpc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c index 43d682341..945600c6b 100644 --- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -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 */ } -- 2.25.1