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udhcpc: shrink

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udhcpc: guard against zero lease time

function                                             old     new   delta
timeout                                                4       -      -4
server_addr                                            4       -      -4
requested_ip                                           4       -      -4
perform_release                                      134     112     -22
udhcpc_main                                         2511    2485     -26
------------------------------------------------------------------------------
(add/remove: 0/3 grow/shrink: 0/2 up/down: 0/-60)             Total: -60 bytes
This commit is contained in:
Denis Vlasenko 2008-05-26 17:32:35 +00:00
parent 6bb55cfb99
commit fc9e108032
3 changed files with 36 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
include/platform.h
View File

@ -135,7 +135,18 @@
#define SWAP_LE64(x) (x)
#endif
/* ---- Unaligned access ------------------------------------ */
/* parameter is supposed to be an uint32_t* ptr */
#if defined(i386) || defined(__x86_64__) /* + other arches? */
#define get_unaligned_u32p(u32p) (*(u32p))
#else
/* performs reasonably well (gcc usually inlines memcpy here) */
#define get_unaligned_u32p(u32p) ({ uint32_t __t; memcpy(&__t, (u32p), 4); __t; })
#endif
/* ---- Networking ------------------------------------------ */
#ifndef __APPLE__
# include <arpa/inet.h>
# ifndef __socklen_t_defined
@ -146,6 +157,7 @@ typedef int socklen_t;
#endif
/* ---- Compiler dependent settings ------------------------- */
#if (defined __digital__ && defined __unix__) || defined __APPLE__
# undef HAVE_MNTENT_H
# undef HAVE_SYS_STATFS_H
@ -163,9 +175,10 @@ __extension__ typedef unsigned long long __u64;
#endif
/*----- Kernel versioning ------------------------------------*/
#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
/* ---- miscellaneous --------------------------------------- */
/* ---- Miscellaneous --------------------------------------- */
#if defined(__GNU_LIBRARY__) && __GNU_LIBRARY__ < 5 && \
!defined(__dietlibc__) && \

33
networking/udhcp/dhcpc.c
View File

@ -18,9 +18,6 @@
#include "options.h"
static int timeout; /* = 0. Must be signed */
static uint32_t requested_ip; /* = 0 */
static uint32_t server_addr;
static int sockfd = -1;
#define LISTEN_NONE 0
@ -28,6 +25,14 @@ static int sockfd = -1;
#define LISTEN_RAW 2
static smallint listen_mode;
#define INIT_SELECTING 0
#define REQUESTING 1
#define BOUND 2
#define RENEWING 3
#define REBINDING 4
#define INIT_REBOOT 5
#define RENEW_REQUESTED 6
#define RELEASED 7
static smallint state;
/* struct client_config_t client_config is in bb_common_bufsiz1 */
@ -71,7 +76,7 @@ static void perform_renew(void)
/* perform a release */
static void perform_release(void)
static void perform_release(uint32_t requested_ip, uint32_t server_addr)
{
char buffer[sizeof("255.255.255.255")];
struct in_addr temp_addr;
@ -90,7 +95,6 @@ static void perform_release(void)
change_listen_mode(LISTEN_NONE);
state = RELEASED;
timeout = INT_MAX;
}
@ -140,9 +144,12 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
int tryagain_timeout = 20;
int discover_timeout = 3;
int discover_retries = 3;
uint32_t server_addr = server_addr; /* for compiler */
uint32_t requested_ip = 0;
uint32_t xid = 0;
uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
int packet_num;
int timeout; /* must be signed */
unsigned already_waited_sec;
unsigned opt;
int max_fd;
@ -332,6 +339,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
packet_num = 0;
timeout = 0;
already_waited_sec = 0;
/* Main event loop. select() waits on signal pipe and possibly
@ -510,8 +518,8 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
continue;
/* still selecting - this server looks bad */
}
/* can be misaligned, thus memcpy */
memcpy(&server_addr, temp, 4);
/* it IS unaligned sometimes, don't "optimize" */
server_addr = get_unaligned_u32p((uint32_t*)temp);
xid = packet.xid;
requested_ip = packet.yiaddr;
@ -535,7 +543,9 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
/* can be misaligned, thus memcpy */
memcpy(&lease_seconds, temp, 4);
lease_seconds = ntohl(lease_seconds);
lease_seconds &= 0x0fffffff; /* paranoia: must not be negative */
lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
if (lease_seconds < 10) /* and not too small */
lease_seconds = 10;
}
#if ENABLE_FEATURE_UDHCPC_ARPING
if (opt & OPT_a) {
@ -576,7 +586,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
change_listen_mode(LISTEN_NONE);
if (client_config.quit_after_lease) {
if (client_config.release_on_quit)
perform_release();
perform_release(requested_ip, server_addr);
goto ret0;
}
if (!client_config.foreground)
@ -618,12 +628,13 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
timeout = 0;
break;
case SIGUSR2:
perform_release();
perform_release(requested_ip, server_addr);
timeout = INT_MAX;
break;
case SIGTERM:
bb_info_msg("Received SIGTERM");
if (client_config.release_on_quit)
perform_release();
perform_release(requested_ip, server_addr);
goto ret0;
}
}

9
networking/udhcp/dhcpc.h
View File

@ -8,15 +8,6 @@
# pragma GCC visibility push(hidden)
#endif
#define INIT_SELECTING 0
#define REQUESTING 1
#define BOUND 2
#define RENEWING 3
#define REBINDING 4
#define INIT_REBOOT 5
#define RENEW_REQUESTED 6
#define RELEASED 7
struct client_config_t {
/* TODO: combine flag fields into single "unsigned opt" */
/* (can be set directly to the result of getopt32) */