From 65c34c52df3ed46f0b811d1858c271a373ab6af5 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 31 May 2019 23:39:22 +0200 Subject: [PATCH] dhcp: get rid of static data signal_pipe 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 --- 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 #include @@ -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; -- 2.25.1