CI: add CodeQL workflow tests
[project/libubox.git] / uloop.c
diff --git a/uloop.c b/uloop.c
index 9fedcce078e836ebb46c8997838aac7c8f7336c4..da6f690cfad63f100f38510d087e81350cc1ea2b 100644 (file)
--- a/uloop.c
+++ b/uloop.c
@@ -1,7 +1,7 @@
 /*
  * uloop - event loop implementation
  *
- * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2010-2016 Felix Fietkau <nbd@openwrt.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -26,6 +26,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <stdbool.h>
+#include <limits.h>
 
 #include "uloop.h"
 #include "utils.h"
@@ -35,6 +36,7 @@
 #endif
 #ifdef USE_EPOLL
 #include <sys/epoll.h>
+#include <sys/timerfd.h>
 #endif
 #include <sys/wait.h>
 
@@ -55,244 +57,110 @@ static struct uloop_fd_stack *fd_stack = NULL;
 
 static struct list_head timeouts = LIST_HEAD_INIT(timeouts);
 static struct list_head processes = LIST_HEAD_INIT(processes);
+static struct list_head signals = LIST_HEAD_INIT(signals);
 
 static int poll_fd = -1;
 bool uloop_cancelled = false;
+bool uloop_handle_sigchld = true;
+static int uloop_status = 0;
 static bool do_sigchld = false;
 
 static struct uloop_fd_event cur_fds[ULOOP_MAX_EVENTS];
 static int cur_fd, cur_nfds;
+static int uloop_run_depth = 0;
 
-#ifdef USE_KQUEUE
-
-int uloop_init(void)
-{
-       struct timespec timeout = { 0, 0 };
-       struct kevent ev = {};
+uloop_fd_handler uloop_fd_set_cb = NULL;
 
-       if (poll_fd >= 0)
-               return 0;
+int uloop_fd_add(struct uloop_fd *sock, unsigned int flags);
 
-       poll_fd = kqueue();
-       if (poll_fd < 0)
-               return -1;
+#ifdef USE_KQUEUE
+#include "uloop-kqueue.c"
+#endif
 
-       EV_SET(&ev, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, 0);
-       kevent(poll_fd, &ev, 1, NULL, 0, &timeout);
+#ifdef USE_EPOLL
+#include "uloop-epoll.c"
+#endif
 
-       return 0;
+static void set_signo(uint64_t *signums, int signo)
+{
+       if (signo >= 1 && signo <= 64)
+               *signums |= (1u << (signo - 1));
 }
 
-
-static uint16_t get_flags(unsigned int flags, unsigned int mask)
+static bool get_signo(uint64_t signums, int signo)
 {
-       uint16_t kflags = 0;
-
-       if (!(flags & mask))
-               return EV_DELETE;
-
-       kflags = EV_ADD;
-       if (flags & ULOOP_EDGE_TRIGGER)
-               kflags |= EV_CLEAR;
-
-       return kflags;
+       return (signo >= 1) && (signo <= 64) && (signums & (1u << (signo - 1)));
 }
 
-static struct kevent events[ULOOP_MAX_EVENTS];
-
-static int register_kevent(struct uloop_fd *fd, unsigned int flags)
+static void signal_consume(struct uloop_fd *fd, unsigned int events)
 {
-       struct timespec timeout = { 0, 0 };
-       struct kevent ev[2];
-       int nev = 0;
-       unsigned int fl = 0;
-       unsigned int changed;
-       uint16_t kflags;
-
-       if (flags & ULOOP_EDGE_DEFER)
-               flags &= ~ULOOP_EDGE_TRIGGER;
+       struct uloop_signal *usig, *usig_next;
+       uint64_t signums = 0;
+       uint8_t buf[32];
+       ssize_t nsigs;
 
-       changed = flags ^ fd->flags;
-       if (changed & ULOOP_EDGE_TRIGGER)
-               changed |= flags;
+       do {
+               nsigs = read(fd->fd, buf, sizeof(buf));
 
-       if (changed & ULOOP_READ) {
-               kflags = get_flags(flags, ULOOP_READ);
-               EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
+               for (ssize_t i = 0; i < nsigs; i++)
+                       set_signo(&signums, buf[i]);
        }
+       while (nsigs > 0);
 
-       if (changed & ULOOP_WRITE) {
-               kflags = get_flags(flags, ULOOP_WRITE);
-               EV_SET(&ev[nev++], fd->fd, EVFILT_WRITE, kflags, 0, 0, fd);
-       }
-
-       if (!flags)
-               fl |= EV_DELETE;
-
-       fd->flags = flags;
-       if (kevent(poll_fd, ev, nev, NULL, fl, &timeout) == -1)
-               return -1;
-
-       return 0;
+       list_for_each_entry_safe(usig, usig_next, &signals, list)
+               if (get_signo(signums, usig->signo))
+                       usig->cb(usig);
 }
 
-static int register_poll(struct uloop_fd *fd, unsigned int flags)
-{
-       if (flags & ULOOP_EDGE_TRIGGER)
-               flags |= ULOOP_EDGE_DEFER;
-       else
-               flags &= ~ULOOP_EDGE_DEFER;
-
-       return register_kevent(fd, flags);
-}
+static int waker_pipe = -1;
+static struct uloop_fd waker_fd = {
+       .fd = -1,
+       .cb = signal_consume,
+};
 
-static int __uloop_fd_delete(struct uloop_fd *fd)
+static void waker_init_fd(int fd)
 {
-       return register_poll(fd, 0);
+       fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+       fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
 }
 
-static int uloop_fetch_events(int timeout)
+static int waker_init(void)
 {
-       struct timespec ts;
-       int nfds, n;
+       int fds[2];
 
-       if (timeout >= 0) {
-               ts.tv_sec = timeout / 1000;
-               ts.tv_nsec = (timeout % 1000) * 1000000;
-       }
-
-       nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout >= 0 ? &ts : NULL);
-       for (n = 0; n < nfds; n++) {
-               struct uloop_fd_event *cur = &cur_fds[n];
-               struct uloop_fd *u = events[n].udata;
-               unsigned int ev = 0;
-
-               cur->fd = u;
-               if (!u)
-                       continue;
-
-               if (events[n].flags & EV_ERROR) {
-                       u->error = true;
-                       if (!(u->flags & ULOOP_ERROR_CB))
-                               uloop_fd_delete(u);
-               }
-
-               if(events[n].filter == EVFILT_READ)
-                       ev |= ULOOP_READ;
-               else if (events[n].filter == EVFILT_WRITE)
-                       ev |= ULOOP_WRITE;
-
-               if (events[n].flags & EV_EOF)
-                       u->eof = true;
-               else if (!ev)
-                       cur->fd = NULL;
-
-               cur->events = ev;
-               if (u->flags & ULOOP_EDGE_DEFER) {
-                       u->flags &= ~ULOOP_EDGE_DEFER;
-                       u->flags |= ULOOP_EDGE_TRIGGER;
-                       register_kevent(u, u->flags);
-               }
-       }
-       return nfds;
-}
-
-#endif
-
-#ifdef USE_EPOLL
-
-/**
- * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
- */
-#ifndef EPOLLRDHUP
-#define EPOLLRDHUP 0x2000
-#endif
-
-int uloop_init(void)
-{
-       if (poll_fd >= 0)
+       if (waker_pipe >= 0)
                return 0;
 
-       poll_fd = epoll_create(32);
-       if (poll_fd < 0)
+       if (pipe(fds) < 0)
                return -1;
 
-       fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
-       return 0;
-}
-
-static int register_poll(struct uloop_fd *fd, unsigned int flags)
-{
-       struct epoll_event ev;
-       int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
-
-       memset(&ev, 0, sizeof(struct epoll_event));
-
-       if (flags & ULOOP_READ)
-               ev.events |= EPOLLIN | EPOLLRDHUP;
+       waker_init_fd(fds[0]);
+       waker_init_fd(fds[1]);
+       waker_pipe = fds[1];
 
-       if (flags & ULOOP_WRITE)
-               ev.events |= EPOLLOUT;
+       waker_fd.fd = fds[0];
+       waker_fd.cb = signal_consume;
+       uloop_fd_add(&waker_fd, ULOOP_READ);
 
-       if (flags & ULOOP_EDGE_TRIGGER)
-               ev.events |= EPOLLET;
-
-       ev.data.fd = fd->fd;
-       ev.data.ptr = fd;
-       fd->flags = flags;
-
-       return epoll_ctl(poll_fd, op, fd->fd, &ev);
+       return 0;
 }
 
-static struct epoll_event events[ULOOP_MAX_EVENTS];
-
-static int __uloop_fd_delete(struct uloop_fd *sock)
-{
-       sock->flags = 0;
-       return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
-}
+static void uloop_setup_signals(bool add);
 
-static int uloop_fetch_events(int timeout)
+int uloop_init(void)
 {
-       int n, nfds;
-
-       nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
-       for (n = 0; n < nfds; ++n) {
-               struct uloop_fd_event *cur = &cur_fds[n];
-               struct uloop_fd *u = events[n].data.ptr;
-               unsigned int ev = 0;
-
-               cur->fd = u;
-               if (!u)
-                       continue;
-
-               if (events[n].events & (EPOLLERR|EPOLLHUP)) {
-                       u->error = true;
-                       if (!(u->flags & ULOOP_ERROR_CB))
-                               uloop_fd_delete(u);
-               }
-
-               if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR|EPOLLHUP))) {
-                       cur->fd = NULL;
-                       continue;
-               }
-
-               if(events[n].events & EPOLLRDHUP)
-                       u->eof = true;
-
-               if(events[n].events & EPOLLIN)
-                       ev |= ULOOP_READ;
-
-               if(events[n].events & EPOLLOUT)
-                       ev |= ULOOP_WRITE;
+       if (uloop_init_pollfd() < 0)
+               return -1;
 
-               cur->events = ev;
+       if (waker_init() < 0) {
+               uloop_done();
+               return -1;
        }
 
-       return nfds;
-}
+       uloop_setup_signals(true);
 
-#endif
+       return 0;
+}
 
 static bool uloop_fd_stack_event(struct uloop_fd *fd, int events)
 {
@@ -320,7 +188,7 @@ static bool uloop_fd_stack_event(struct uloop_fd *fd, int events)
        return false;
 }
 
-static void uloop_run_events(int timeout)
+static void uloop_run_events(int64_t timeout)
 {
        struct uloop_fd_event *cur;
        struct uloop_fd *fd;
@@ -382,6 +250,10 @@ int uloop_fd_add(struct uloop_fd *sock, unsigned int flags)
        if (ret < 0)
                goto out;
 
+       if (uloop_fd_set_cb)
+               uloop_fd_set_cb(sock, flags);
+
+       sock->flags = flags;
        sock->registered = true;
        sock->eof = false;
        sock->error = false;
@@ -392,6 +264,7 @@ out:
 
 int uloop_fd_delete(struct uloop_fd *fd)
 {
+       int ret;
        int i;
 
        for (i = 0; i < cur_nfds; i++) {
@@ -404,12 +277,18 @@ int uloop_fd_delete(struct uloop_fd *fd)
        if (!fd->registered)
                return 0;
 
+       if (uloop_fd_set_cb)
+               uloop_fd_set_cb(fd, 0);
+
        fd->registered = false;
        uloop_fd_stack_event(fd, -1);
-       return __uloop_fd_delete(fd);
+       ret = __uloop_fd_delete(fd);
+       fd->flags = 0;
+
+       return ret;
 }
 
-static int tv_diff(struct timeval *t1, struct timeval *t2)
+static int64_t tv_diff(struct timeval *t1, struct timeval *t2)
 {
        return
                (t1->tv_sec - t2->tv_sec) * 1000 +
@@ -453,14 +332,14 @@ int uloop_timeout_set(struct uloop_timeout *timeout, int msecs)
        if (timeout->pending)
                uloop_timeout_cancel(timeout);
 
-       uloop_gettime(&timeout->time);
+       uloop_gettime(time);
 
        time->tv_sec += msecs / 1000;
        time->tv_usec += (msecs % 1000) * 1000;
 
        if (time->tv_usec > 1000000) {
                time->tv_sec++;
-               time->tv_usec %= 1000000;
+               time->tv_usec -= 1000000;
        }
 
        return uloop_timeout_add(timeout);
@@ -478,6 +357,26 @@ int uloop_timeout_cancel(struct uloop_timeout *timeout)
 }
 
 int uloop_timeout_remaining(struct uloop_timeout *timeout)
+{
+       int64_t td;
+       struct timeval now;
+
+       if (!timeout->pending)
+               return -1;
+
+       uloop_gettime(&now);
+
+       td = tv_diff(&timeout->time, &now);
+
+       if (td > INT_MAX)
+               return INT_MAX;
+       else if (td < INT_MIN)
+               return INT_MIN;
+       else
+               return (int)td;
+}
+
+int64_t uloop_timeout_remaining64(struct uloop_timeout *timeout)
 {
        struct timeval now;
 
@@ -531,6 +430,9 @@ static void uloop_handle_processes(void)
 
        while (1) {
                pid = waitpid(-1, &ret, WNOHANG);
+               if (pid < 0 && errno == EINTR)
+                       continue;
+
                if (pid <= 0)
                        return;
 
@@ -548,64 +450,182 @@ static void uloop_handle_processes(void)
 
 }
 
+int uloop_interval_set(struct uloop_interval *timer, unsigned int msecs)
+{
+       return timer_register(timer, msecs);
+}
+
+int uloop_interval_cancel(struct uloop_interval *timer)
+{
+       return timer_remove(timer);
+}
+
+int64_t uloop_interval_remaining(struct uloop_interval *timer)
+{
+       return timer_next(timer);
+}
+
+static void uloop_signal_wake(int signo)
+{
+       uint8_t sigbyte = signo;
+
+       if (signo == SIGCHLD)
+               do_sigchld = true;
+
+       do {
+               if (write(waker_pipe, &sigbyte, 1) < 0) {
+                       if (errno == EINTR)
+                               continue;
+               }
+               break;
+       } while (1);
+}
+
 static void uloop_handle_sigint(int signo)
 {
+       uloop_status = signo;
        uloop_cancelled = true;
+       uloop_signal_wake(signo);
 }
 
-static void uloop_sigchld(int signo)
+static void uloop_install_handler(int signum, void (*handler)(int), struct sigaction* old, bool add)
 {
-       do_sigchld = true;
+       struct sigaction s;
+       struct sigaction *act;
+
+       act = NULL;
+       sigaction(signum, NULL, &s);
+
+       if (add) {
+               if (s.sa_handler == SIG_DFL) { /* Do not override existing custom signal handlers */
+                       memcpy(old, &s, sizeof(struct sigaction));
+                       s.sa_handler = handler;
+                       s.sa_flags = 0;
+                       act = &s;
+               }
+       }
+       else if (s.sa_handler == handler) { /* Do not restore if someone modified our handler */
+                       act = old;
+       }
+
+       if (act != NULL)
+               sigaction(signum, act, NULL);
 }
 
-static void uloop_setup_signals(bool add)
+static void uloop_ignore_signal(int signum, bool ignore)
 {
-       static struct sigaction old_sigint, old_sigchld;
        struct sigaction s;
+       void *new_handler = NULL;
 
-       memset(&s, 0, sizeof(struct sigaction));
+       sigaction(signum, NULL, &s);
 
-       if (add) {
-               s.sa_handler = uloop_handle_sigint;
-               s.sa_flags = 0;
+       if (ignore) {
+               if (s.sa_handler == SIG_DFL) /* Ignore only if there isn't any custom handler */
+                       new_handler = SIG_IGN;
        } else {
-               s = old_sigint;
+               if (s.sa_handler == SIG_IGN) /* Restore only if noone modified our SIG_IGN */
+                       new_handler = SIG_DFL;
        }
 
-       sigaction(SIGINT, &s, &old_sigint);
+       if (new_handler) {
+               s.sa_handler = new_handler;
+               s.sa_flags = 0;
+               sigaction(signum, &s, NULL);
+       }
+}
 
-       if (add)
-               s.sa_handler = uloop_sigchld;
-       else
-               s = old_sigchld;
+static void uloop_setup_signals(bool add)
+{
+       static struct sigaction old_sigint, old_sigchld, old_sigterm;
+
+       uloop_install_handler(SIGINT, uloop_handle_sigint, &old_sigint, add);
+       uloop_install_handler(SIGTERM, uloop_handle_sigint, &old_sigterm, add);
+
+       if (uloop_handle_sigchld)
+               uloop_install_handler(SIGCHLD, uloop_signal_wake, &old_sigchld, add);
 
-       sigaction(SIGCHLD, &s, &old_sigchld);
+       uloop_ignore_signal(SIGPIPE, add);
 }
 
-static int uloop_get_next_timeout(struct timeval *tv)
+int uloop_signal_add(struct uloop_signal *s)
+{
+       struct list_head *h = &signals;
+       struct uloop_signal *tmp;
+       struct sigaction sa;
+
+       if (s->pending)
+               return -1;
+
+       list_for_each_entry(tmp, &signals, list) {
+               if (tmp->signo > s->signo) {
+                       h = &tmp->list;
+                       break;
+               }
+       }
+
+       list_add_tail(&s->list, h);
+       s->pending = true;
+
+       sigaction(s->signo, NULL, &s->orig);
+
+       if (s->orig.sa_handler != uloop_signal_wake) {
+               sa.sa_handler = uloop_signal_wake;
+               sa.sa_flags = 0;
+               sigemptyset(&sa.sa_mask);
+               sigaction(s->signo, &sa, NULL);
+       }
+
+       return 0;
+}
+
+int uloop_signal_delete(struct uloop_signal *s)
+{
+       if (!s->pending)
+               return -1;
+
+       list_del(&s->list);
+       s->pending = false;
+
+       if (s->orig.sa_handler != uloop_signal_wake)
+               sigaction(s->signo, &s->orig, NULL);
+
+       return 0;
+}
+
+int uloop_get_next_timeout(void)
 {
        struct uloop_timeout *timeout;
-       int diff;
+       struct timeval tv;
+       int64_t diff;
 
        if (list_empty(&timeouts))
                return -1;
 
+       uloop_gettime(&tv);
+
        timeout = list_first_entry(&timeouts, struct uloop_timeout, list);
-       diff = tv_diff(&timeout->time, tv);
+       diff = tv_diff(&timeout->time, &tv);
        if (diff < 0)
                return 0;
+       if (diff > INT_MAX)
+               return INT_MAX;
 
        return diff;
 }
 
-static void uloop_process_timeouts(struct timeval *tv)
+static void uloop_process_timeouts(void)
 {
        struct uloop_timeout *t;
+       struct timeval tv;
+
+       if (list_empty(&timeouts))
+               return;
 
+       uloop_gettime(&tv);
        while (!list_empty(&timeouts)) {
                t = list_first_entry(&timeouts, struct uloop_timeout, list);
 
-               if (tv_diff(&t->time, tv) > 0)
+               if (tv_diff(&t->time, &tv) > 0)
                        break;
 
                uloop_timeout_cancel(t);
@@ -630,43 +650,54 @@ static void uloop_clear_processes(void)
                uloop_process_delete(p);
 }
 
-void uloop_run(void)
+bool uloop_cancelling(void)
 {
-       static int recursive_calls = 0;
-       struct timeval tv;
+       return uloop_run_depth > 0 && uloop_cancelled;
+}
 
-       /*
-        * Handlers are only updated for the first call to uloop_run() (and restored
-        * when this call is done).
-        */
-       if (!recursive_calls++)
-               uloop_setup_signals(true);
+int uloop_run_timeout(int timeout)
+{
+       int next_time = 0;
+
+       uloop_run_depth++;
 
+       uloop_status = 0;
        uloop_cancelled = false;
-       while(!uloop_cancelled)
-       {
-               uloop_gettime(&tv);
-               uloop_process_timeouts(&tv);
-               if (uloop_cancelled)
-                       break;
+       do {
+               uloop_process_timeouts();
 
                if (do_sigchld)
                        uloop_handle_processes();
-               uloop_gettime(&tv);
-               uloop_run_events(uloop_get_next_timeout(&tv));
-       }
 
-       if (!--recursive_calls)
-               uloop_setup_signals(false);
+               if (uloop_cancelled)
+                       break;
+
+               next_time = uloop_get_next_timeout();
+               if (timeout >= 0 && (next_time < 0 || timeout < next_time))
+                               next_time = timeout;
+               uloop_run_events(next_time);
+       } while (!uloop_cancelled && timeout < 0);
+
+       --uloop_run_depth;
+
+       return uloop_status;
 }
 
 void uloop_done(void)
 {
-       if (poll_fd < 0)
-               return;
+       uloop_setup_signals(false);
 
-       close(poll_fd);
-       poll_fd = -1;
+       if (poll_fd >= 0) {
+               close(poll_fd);
+               poll_fd = -1;
+       }
+
+       if (waker_pipe >= 0) {
+               uloop_fd_delete(&waker_fd);
+               close(waker_pipe);
+               close(waker_fd.fd);
+               waker_pipe = -1;
+       }
 
        uloop_clear_timeouts();
        uloop_clear_processes();