From: Denys Vlasenko Date: Thu, 16 Feb 2017 22:25:44 +0000 (+0100) Subject: udhcp: use poll() instead of select() X-Git-Tag: 1_27_0~118 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=52a515d18724bbb34e3ccbbb0218efcc4eccc0a8;p=oweals%2Fbusybox.git udhcp: use poll() instead of select() function old new delta udhcp_sp_read 65 46 -19 udhcp_sp_fd_set 79 54 -25 udhcpd_main 1530 1482 -48 udhcpc_main 2780 2730 -50 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-142) Total: -142 bytes Signed-off-by: Denys Vlasenko --- diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h index a526494d7..ee12cf91b 100644 --- a/networking/udhcp/common.h +++ b/networking/udhcp/common.h @@ -300,8 +300,8 @@ int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, uint32_t dest_nip, int dest_port) FAST_FUNC; void udhcp_sp_setup(void) FAST_FUNC; -int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC; -int udhcp_sp_read(const fd_set *rfds) FAST_FUNC; +void udhcp_sp_fd_set(struct pollfd *pfds, int extra_fd) FAST_FUNC; +int udhcp_sp_read(struct pollfd *pfds) FAST_FUNC; int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC; diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c index 64339c9b5..067d35115 100644 --- a/networking/udhcp/d6_dhcpc.c +++ b/networking/udhcp/d6_dhcpc.c @@ -935,9 +935,7 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv) int timeout; /* must be signed */ unsigned already_waited_sec; unsigned opt; - int max_fd; int retval; - fd_set rfds; setup_common_bufsiz(); @@ -1063,7 +1061,8 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv) * "continue" statements in code below jump to the top of the loop. */ for (;;) { - struct timeval tv; + int tv; + struct pollfd pfds[2]; struct d6_packet packet; uint8_t *packet_end; /* silence "uninitialized!" warning */ @@ -1078,16 +1077,15 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv) * to change_listen_mode(). Thus we open listen socket * BEFORE we send renew request (see "case BOUND:"). */ - max_fd = udhcp_sp_fd_set(&rfds, sockfd); + udhcp_sp_fd_set(pfds, sockfd); - tv.tv_sec = timeout - already_waited_sec; - tv.tv_usec = 0; + tv = timeout - already_waited_sec; retval = 0; /* If we already timed out, fall through with retval = 0, else... */ - if ((int)tv.tv_sec > 0) { - log1("waiting on select %u seconds", (int)tv.tv_sec); + if (tv > 0) { + log1("waiting on select %u seconds", tv); timestamp_before_wait = (unsigned)monotonic_sec(); - retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); + retval = poll(pfds, 2, tv * 1000); if (retval < 0) { /* EINTR? A signal was caught, don't panic */ if (errno == EINTR) { @@ -1222,8 +1220,8 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv) /* select() didn't timeout, something happened */ /* Is it a signal? */ - /* note: udhcp_sp_read checks FD_ISSET before reading */ - switch (udhcp_sp_read(&rfds)) { + /* note: udhcp_sp_read checks poll result before reading */ + switch (udhcp_sp_read(pfds)) { case SIGUSR1: client_config.first_secs = 0; /* make secs field count from 0 */ already_waited_sec = 0; @@ -1258,7 +1256,7 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv) } /* Is it a packet? */ - if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds)) + if (listen_mode == LISTEN_NONE || !pfds[1].revents) continue; /* no */ { @@ -1460,8 +1458,8 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv) if (lease_seconds < 0x10) lease_seconds = 0x10; /// TODO: check for 0 lease time? - if (lease_seconds >= 0x10000000) - lease_seconds = 0x0fffffff; + if (lease_seconds > 0x7fffffff / 1000) + lease_seconds = 0x7fffffff / 1000; /* enter bound state */ timeout = lease_seconds / 2; bb_error_msg("lease obtained, lease time %u", diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c index 0e236261b..8f7f59e08 100644 --- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -1281,9 +1281,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) unsigned already_waited_sec; unsigned opt; IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;) - int max_fd; int retval; - fd_set rfds; setup_common_bufsiz(); @@ -1432,7 +1430,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * "continue" statements in code below jump to the top of the loop. */ for (;;) { - struct timeval tv; + int tv; + struct pollfd pfds[2]; struct dhcp_packet packet; /* silence "uninitialized!" warning */ unsigned timestamp_before_wait = timestamp_before_wait; @@ -1446,16 +1445,15 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * to change_listen_mode(). Thus we open listen socket * BEFORE we send renew request (see "case BOUND:"). */ - max_fd = udhcp_sp_fd_set(&rfds, sockfd); + udhcp_sp_fd_set(pfds, sockfd); - tv.tv_sec = timeout - already_waited_sec; - tv.tv_usec = 0; + tv = timeout - already_waited_sec; retval = 0; /* If we already timed out, fall through with retval = 0, else... */ - if ((int)tv.tv_sec > 0) { - log1("waiting on select %u seconds", (int)tv.tv_sec); + if (tv > 0) { + log1("waiting on select %u seconds", tv); timestamp_before_wait = (unsigned)monotonic_sec(); - retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); + retval = poll(pfds, 2, tv * 1000); if (retval < 0) { /* EINTR? A signal was caught, don't panic */ if (errno == EINTR) { @@ -1591,8 +1589,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) /* select() didn't timeout, something happened */ /* Is it a signal? */ - /* note: udhcp_sp_read checks FD_ISSET before reading */ - switch (udhcp_sp_read(&rfds)) { + /* note: udhcp_sp_read checks poll result before reading */ + switch (udhcp_sp_read(pfds)) { case SIGUSR1: client_config.first_secs = 0; /* make secs field count from 0 */ already_waited_sec = 0; @@ -1627,7 +1625,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) } /* Is it a packet? */ - if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds)) + if (listen_mode == LISTEN_NONE || !pfds[1].revents) continue; /* no */ { @@ -1742,8 +1740,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) /* paranoia: must not be too small and not prone to overflows */ if (lease_seconds < 0x10) lease_seconds = 0x10; - if (lease_seconds >= 0x10000000) - lease_seconds = 0x0fffffff; + if (lease_seconds > 0x7fffffff / 1000) + lease_seconds = 0x7fffffff / 1000; } #if ENABLE_FEATURE_UDHCPC_ARPING if (opt & OPT_a) { diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c index e116ba3af..5eff026bc 100644 --- a/networking/udhcp/dhcpd.c +++ b/networking/udhcp/dhcpd.c @@ -794,7 +794,7 @@ static NOINLINE void send_inform(struct dhcp_packet *oldpacket) int udhcpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int udhcpd_main(int argc UNUSED_PARAM, char **argv) { - int server_socket = -1, retval, max_sock; + int server_socket = -1, retval; uint8_t *state; unsigned timeout_end; unsigned num_ips; @@ -891,10 +891,10 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv) continue_with_autotime: timeout_end = monotonic_sec() + server_config.auto_time; while (1) { /* loop until universe collapses */ - fd_set rfds; + struct pollfd pfds[2]; struct dhcp_packet packet; int bytes; - struct timeval tv; + int tv; uint8_t *server_id_opt; uint8_t *requested_ip_opt; uint32_t requested_nip = requested_nip; /* for compiler */ @@ -906,16 +906,11 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv) server_config.interface); } - max_sock = udhcp_sp_fd_set(&rfds, server_socket); - if (server_config.auto_time) { - /* cast to signed is essential if tv_sec is wider than int */ - tv.tv_sec = (int)(timeout_end - monotonic_sec()); - tv.tv_usec = 0; - } + udhcp_sp_fd_set(pfds, server_socket); + tv = timeout_end - monotonic_sec(); retval = 0; - if (!server_config.auto_time || tv.tv_sec > 0) { - retval = select(max_sock + 1, &rfds, NULL, NULL, - server_config.auto_time ? &tv : NULL); + if (!server_config.auto_time || tv > 0) { + retval = poll(pfds, 2, server_config.auto_time ? tv * 1000 : -1); } if (retval == 0) { write_leases(); @@ -926,7 +921,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv) continue; } - switch (udhcp_sp_read(&rfds)) { + switch (udhcp_sp_read(pfds)) { case SIGUSR1: bb_error_msg("received %s", "SIGUSR1"); write_leases(); diff --git a/networking/udhcp/signalpipe.c b/networking/udhcp/signalpipe.c index 30bccd6bf..b101b4ce4 100644 --- a/networking/udhcp/signalpipe.c +++ b/networking/udhcp/signalpipe.c @@ -48,28 +48,29 @@ void FAST_FUNC udhcp_sp_setup(void) , signal_handler); } -/* Quick little function to setup the rfds. Will return the - * max_fd for use with select. Limited in that you can only pass - * one extra fd */ -int FAST_FUNC udhcp_sp_fd_set(fd_set *rfds, int extra_fd) +/* Quick little function to setup the pfds. + * Limited in that you can only pass one extra fd. + */ +void FAST_FUNC udhcp_sp_fd_set(struct pollfd pfds[2], int extra_fd) { - FD_ZERO(rfds); - FD_SET(signal_pipe.rd, rfds); + pfds[0].fd = signal_pipe.rd; + pfds[0].events = POLLIN; + pfds[1].fd = -1; if (extra_fd >= 0) { close_on_exec_on(extra_fd); - FD_SET(extra_fd, rfds); + pfds[1].fd = extra_fd; + pfds[1].events = POLLIN; } - return signal_pipe.rd > extra_fd ? signal_pipe.rd : extra_fd; } /* Read a signal from the signal pipe. Returns 0 if there is * no signal, -1 on error (and sets errno appropriately), and * your signal on success */ -int FAST_FUNC udhcp_sp_read(const fd_set *rfds) +int FAST_FUNC udhcp_sp_read(struct pollfd pfds[2]) { unsigned char sig; - if (!FD_ISSET(signal_pipe.rd, rfds)) + if (!pfds[0].revents) return 0; if (safe_read(signal_pipe.rd, &sig, 1) != 1)