[git commit] dhcp: get rid of static data signal_pipe
Denys Vlasenko
vda.linux at googlemail.com
Fri May 31 21:39:22 UTC 2019
commit: https://git.busybox.net/busybox/commit/?id=65c34c52df3ed46f0b811d1858c271a373ab6af5
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
udhcp_sp_setup 65 110 +45
udhcp_sp_fd_set 60 59 -1
udhcpd_main 1442 1437 -5
udhcpc_main 2684 2679 -5
signal_pipe 8 - -8
packed_usage 33292 33284 -8
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/4 up/down: 45/-27) Total: 18 bytes
text data bss dec hex filename
952746 481 7296 960523 ea80b busybox_old
952768 481 7288 960537 ea819 busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
networking/udhcp/d6_dhcpc.c | 8 ++++----
networking/udhcp/dhcpc.c | 8 ++++----
networking/udhcp/dhcpd.c | 12 ++++++------
networking/udhcp/signalpipe.c | 31 ++++++++++++++++++++++---------
4 files changed, 36 insertions(+), 23 deletions(-)
diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index 15e9f3924..02766ba16 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -1174,6 +1174,10 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
client_data.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
client_data.sockfd = -1;
+ /* Make sure fd 0,1,2 are open */
+ /* Set up the signal pipe on fds 3,4 - must be before openlog() */
+ udhcp_sp_setup();
+
/* Parse command line */
opt = getopt32long(argv, "^"
/* O,x: list; -T,-t,-A take numeric param */
@@ -1268,14 +1272,10 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
logmode |= LOGMODE_SYSLOG;
}
- /* Make sure fd 0,1,2 are open */
- bb_sanitize_stdio();
/* Create pidfile */
write_pidfile(client_data.pidfile);
/* Goes to stdout (unless NOMMU) and possibly syslog */
bb_info_msg("started, v"BB_VER);
- /* Set up the signal pipe */
- udhcp_sp_setup();
client_data.state = INIT_SELECTING;
d6_run_script_no_option("deconfig");
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index cb85fa9e3..f040e93f7 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1271,6 +1271,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
client_data.sockfd = -1;
str_V = "udhcp "BB_VER;
+ /* Make sure fd 0,1,2 are open */
+ /* Set up the signal pipe on fds 3,4 - must be before openlog() */
+ udhcp_sp_setup();
+
/* Parse command line */
opt = getopt32long(argv, "^"
/* O,x: list; -T,-t,-A take numeric param */
@@ -1385,14 +1389,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
logmode |= LOGMODE_SYSLOG;
}
- /* Make sure fd 0,1,2 are open */
- bb_sanitize_stdio();
/* Create pidfile */
write_pidfile(client_data.pidfile);
/* Goes to stdout (unless NOMMU) and possibly syslog */
bb_info_msg("started, v"BB_VER);
- /* Set up the signal pipe */
- udhcp_sp_setup();
/* We want random_xid to be random... */
srand(monotonic_us());
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 6e426e6a2..022b8721b 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -37,6 +37,8 @@
//usage: IF_FEATURE_UDHCP_PORT(
//usage: "\n -P N Use port N (default 67)"
//usage: )
+//usage: "\nSignals:"
+//usage: "\n USR1 Update lease file"
#include <netinet/ether.h>
#include <syslog.h>
@@ -863,6 +865,10 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
+ /* Make sure fd 0,1,2 are open */
+ /* Setup the signal pipe on fds 3,4 - must be before openlog() */
+ udhcp_sp_setup();
+
opt = getopt32(argv, "^"
"fSI:va:"IF_FEATURE_UDHCP_PORT("P:")
"\0"
@@ -904,9 +910,6 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
if (server_data.auto_time > INT_MAX / 1000)
server_data.auto_time = INT_MAX / 1000;
- /* Make sure fd 0,1,2 are open */
- bb_sanitize_stdio();
-
/* Create pidfile */
write_pidfile(server_data.pidfile);
/* if (!..) bb_perror_msg("can't create pidfile %s", pidfile); */
@@ -942,9 +945,6 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
goto ret;
}
- /* Setup the signal pipe */
- udhcp_sp_setup();
-
continue_with_autotime:
timeout_end = monotonic_sec() + server_data.auto_time;
while (1) { /* loop until universe collapses */
diff --git a/networking/udhcp/signalpipe.c b/networking/udhcp/signalpipe.c
index 2ff78f0f2..81d1fc01a 100644
--- a/networking/udhcp/signalpipe.c
+++ b/networking/udhcp/signalpipe.c
@@ -20,14 +20,14 @@
*/
#include "common.h"
-/* Global variable: we access it from signal handler */
-static struct fd_pair signal_pipe;
+#define READ_FD 3
+#define WRITE_FD 4
static void signal_handler(int sig)
{
int sv = errno;
unsigned char ch = sig; /* use char, avoid dealing with partial writes */
- if (write(signal_pipe.wr, &ch, 1) != 1)
+ if (write(WRITE_FD, &ch, 1) != 1)
bb_perror_msg("can't send signal");
errno = sv;
}
@@ -36,12 +36,25 @@ static void signal_handler(int sig)
* and installs the signal handler */
void FAST_FUNC udhcp_sp_setup(void)
{
+ struct fd_pair signal_pipe;
+
+ /* All callers also want this, so... */
+ bb_sanitize_stdio();
+
/* was socketpair, but it needs AF_UNIX in kernel */
xpiped_pair(signal_pipe);
- close_on_exec_on(signal_pipe.rd);
- close_on_exec_on(signal_pipe.wr);
- ndelay_on(signal_pipe.rd);
- ndelay_on(signal_pipe.wr);
+
+ /* usually we get fds 3 and 4, but if we get higher ones... */
+ if (signal_pipe.rd != READ_FD)
+ xmove_fd(signal_pipe.rd, READ_FD);
+ if (signal_pipe.wr != WRITE_FD)
+ xmove_fd(signal_pipe.wr, WRITE_FD);
+
+ close_on_exec_on(READ_FD);
+ close_on_exec_on(WRITE_FD);
+ ndelay_on(READ_FD);
+ ndelay_on(WRITE_FD);
+
bb_signals(0
+ (1 << SIGUSR1)
+ (1 << SIGUSR2)
@@ -54,7 +67,7 @@ void FAST_FUNC udhcp_sp_setup(void)
*/
void FAST_FUNC udhcp_sp_fd_set(struct pollfd pfds[2], int extra_fd)
{
- pfds[0].fd = signal_pipe.rd;
+ pfds[0].fd = READ_FD;
pfds[0].events = POLLIN;
pfds[1].fd = -1;
if (extra_fd >= 0) {
@@ -74,7 +87,7 @@ int FAST_FUNC udhcp_sp_read(void)
unsigned char sig;
/* Can't block here, fd is in nonblocking mode */
- if (safe_read(signal_pipe.rd, &sig, 1) != 1)
+ if (safe_read(READ_FD, &sig, 1) != 1)
return 0;
return sig;
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