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Separate event state gathering from action dispatch in main epoll loop.

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This is the first step towards using coroutines.
This commit is contained in:
Nicholas J. Kain
2015-02-15 06:38:03 -05:00
parent 658d2954b8
commit 61387408d0
10 changed files with 437 additions and 223 deletions
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115
src/ndhc.c
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@@ -182,7 +182,13 @@ static void setup_signals_ndhc(void)
epoll_add(cs.epollFd, cs.signalFd);
}
static void signal_dispatch(void)
enum {
SIGNAL_NONE = 0,
SIGNAL_RENEW,
SIGNAL_RELEASE
};
static int signal_dispatch(void)
{
struct signalfd_siginfo si;
memset(&si, 0, sizeof si);
@@ -190,24 +196,22 @@ static void signal_dispatch(void)
if (r < 0) {
log_error("%s: ndhc: error reading from signalfd: %s",
client_config.interface, strerror(errno));
return;
return SIGNAL_NONE;
}
if ((size_t)r < sizeof si) {
log_error("%s: ndhc: short read from signalfd: %zd < %zu",
client_config.interface, r, sizeof si);
return;
return SIGNAL_NONE;
}
switch (si.ssi_signo) {
case SIGUSR1: force_renew_action(&cs); break;
case SIGUSR2: force_release_action(&cs); break;
case SIGUSR1: return SIGNAL_RENEW;
case SIGUSR2: return SIGNAL_RELEASE;
case SIGCHLD:
suicide("ndhc-master: Subprocess terminated unexpectedly. Exiting.");
break;
case SIGTERM:
log_line("Received SIGTERM. Exiting gracefully.");
exit(EXIT_SUCCESS);
break;
default: break;
default: return SIGNAL_NONE;
}
}
@@ -261,6 +265,7 @@ static void fail_if_state_dir_dne(void)
#define NDHC_NUM_EP_FDS 7
static void do_ndhc_work(void)
{
struct dhcpmsg dhcp_packet;
struct epoll_event events[NDHC_NUM_EP_FDS];
long long nowts;
int timeout;
@@ -284,27 +289,53 @@ static void do_ndhc_work(void)
goto jumpstart;
for (;;) {
int r = epoll_wait(cs.epollFd, events, NDHC_NUM_EP_FDS, timeout);
if (r < 0) {
int maxi = epoll_wait(cs.epollFd, events, NDHC_NUM_EP_FDS, timeout);
if (maxi < 0) {
if (errno == EINTR)
continue;
else
suicide("epoll_wait failed");
}
for (int i = 0; i < r; ++i) {
for (int i = 0; i < maxi; ++i) {
int fd = events[i].data.fd;
if (fd == cs.signalFd) {
if (events[i].events & EPOLLIN)
signal_dispatch();
if (!(events[i].events & EPOLLIN))
return;
int sigv = signal_dispatch();
if (sigv == SIGNAL_RENEW)
force_renew_action(&cs);
else if (sigv == SIGNAL_RELEASE)
force_release_action(&cs);
} else if (fd == cs.listenFd) {
if (events[i].events & EPOLLIN)
handle_packet(&cs);
if (!(events[i].events & EPOLLIN))
return;
uint32_t srcaddr;
uint8_t msgtype;
int r = dhcp_packet_get(&cs, &dhcp_packet, &msgtype, &srcaddr);
if (!r)
packet_action(&cs, &dhcp_packet, msgtype, srcaddr);
} else if (fd == cs.arpFd) {
if (events[i].events & EPOLLIN)
handle_arp_response(&cs);
if (!(events[i].events & EPOLLIN))
return;
int r = arp_packet_get(&cs);
if (r == ARPR_PENDING) {
arp_packet_action(&cs);
} else if (r == ARPR_ERROR) {
if (garp.state == AS_COLLISION_CHECK)
arp_failed(&cs);
else if (garp.state == AS_GW_CHECK)
arp_gw_failed(&cs);
else
arp_reopen_fd(&cs);
handle_arp_timeout(&cs, curms());
} else if (r == ARPR_CLOSED)
handle_arp_timeout(&cs, curms());
} else if (fd == cs.nlFd) {
if (events[i].events & EPOLLIN)
handle_nl_message(&cs);
if (!(events[i].events & EPOLLIN))
return;
int nl_event = nl_event_get(&cs);
if (nl_event != IFS_NONE)
nl_event_react(&cs, nl_event);
} else if (fd == ifchStream[0]) {
if (events[i].events & (EPOLLHUP|EPOLLERR|EPOLLRDHUP))
exit(EXIT_FAILURE);
@@ -312,8 +343,30 @@ static void do_ndhc_work(void)
if (events[i].events & (EPOLLHUP|EPOLLERR|EPOLLRDHUP))
exit(EXIT_FAILURE);
} else if (fd == cs.rfkillFd && client_config.enable_rfkill) {
if (events[i].events & EPOLLIN)
handle_rfkill_notice(&cs, client_config.rfkillIdx);
if (!(events[i].events & EPOLLIN))
return;
int rfk = rfkill_get(&cs, 1, client_config.rfkillIdx);
if (rfk == RFK_ENABLED) {
cs.rfkill_set = 1;
if (cs.ifsPrevState == IFS_UP) {
log_line("rfkill: radio now blocked; bringing interface down");
cs.ifsPrevState = IFS_DOWN;
ifnocarrier_action(&cs);
} else
log_line("rfkill: radio now blocked, but interface isn't up");
} else if (rfk == RFK_DISABLED) {
cs.rfkill_set = 0;
if (cs.ifsPrevState == IFS_DOWN) {
log_line("rfkill: radio now unblocked; bringing interface up");
cs.ifsPrevState = IFS_UP;
ifup_action(&cs);
} else {
if (cs.ifsPrevState == IFS_SHUT)
log_line("rfkill: radio now unblocked, but interface was shut down by user");
else
log_line("rfkill: radio now unblocked, but interface is removed");
}
}
} else
suicide("epoll_wait: unknown fd");
}
@@ -461,7 +514,6 @@ void background(void)
static void wait_for_rfkill()
{
cs.rfkill_set = 1;
struct epoll_event events[2];
cs.rfkillFd = rfkill_open(&client_config.enable_rfkill);
if (cs.rfkillFd < 0)
@@ -480,13 +532,20 @@ static void wait_for_rfkill()
}
for (int i = 0; i < r; ++i) {
int fd = events[i].data.fd;
if (fd == cs.rfkillFd) {
if (events[i].events & EPOLLIN) {
if (!rfkill_wait_for_end(&cs))
goto rfkill_gone;
}
} else
if (fd != cs.rfkillFd)
suicide("epoll_wait: unknown fd");
if (events[i].events & EPOLLIN) {
int rfk = rfkill_get(&cs, 0, 0);
if (rfk == RFK_DISABLED) {
switch (perform_ifup()) {
case 1: case 0: goto rfkill_gone;
case -3:
log_line("rfkill: radio immediately blocked again; spurious?");
break;
default: suicide("failed to set the interface to up state");
}
}
}
}
}
rfkill_gone: