Use a unified epoll_(add|del)().

Also, background() and setup_signals_ndhc() are moved from sys.c to ndhc.c.

background() also no longer attempts to re-configure signals; signals are
always set up on initial ndhc initialization.

ndhc/arp.c

@@ -43,6 +43,7 @@
 #include "state.h"
 #include "dhcp.h"
 #include "sys.h"
+#include "ndhc.h"
 #include "ifchange.h"
 #include "options.h"
 #include "leasefile.h"
@@ -234,7 +235,7 @@ static int arp_open_fd(struct client_state_t *cs)
     }
 
     cs->arpFd = fd;
-    epoll_add(cs, fd);
+    epoll_add(cs->epollFd, fd);
     arpreply_clear();
     return 0;
 out_fd:
@@ -274,7 +275,7 @@ static int arp_min_close_fd(struct client_state_t *cs)
 {
     if (cs->arpFd == -1)
         return 0;
-    epoll_del(cs, cs->arpFd);
+    epoll_del(cs->epollFd, cs->arpFd);
     close(cs->arpFd);
     cs->arpFd = -1;
     arpState = AS_NONE;
@@ -498,7 +499,7 @@ void arp_success(struct client_state_t *cs)
     if (client_config.quit_after_lease)
         exit(EXIT_SUCCESS);
     if (!client_config.foreground)
-        background(cs);
+        background();
 }
 
 static void arp_gw_success(struct client_state_t *cs)

ndhc/dhcp.c

@@ -465,7 +465,7 @@ static void change_listen_mode(struct client_state_t *cs, int new_mode)
 {
     cs->listenMode = new_mode;
     if (cs->listenFd >= 0) {
-        epoll_del(cs, cs->listenFd);
+        epoll_del(cs->epollFd, cs->listenFd);
         close(cs->listenFd);
         cs->listenFd = -1;
     }
@@ -478,7 +478,7 @@ static void change_listen_mode(struct client_state_t *cs, int new_mode)
         log_error("FATAL: Couldn't listen on socket: %s.", strerror(errno));
         exit(EXIT_FAILURE);
     }
-    epoll_add(cs, cs->listenFd);
+    epoll_add(cs->epollFd, cs->listenFd);
 }
 
 void set_listen_raw(struct client_state_t *cs)

ndhc/ifchd.c

@@ -56,6 +56,7 @@
 #include "strl.h"
 #include "cap.h"
 #include "io.h"
+#include "sys.h"
 #include "ifset.h"
 #include "seccomp.h"
 
@@ -81,29 +82,6 @@ static void writeordie(int fd, const char *buf, int len)
         suicide("write returned error");
 }
 
-static void ep_add(int fd)
-{
-    struct epoll_event ev;
-    ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
-    ev.data.fd = fd;
-    int r = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev);
-    if (r == -1)
-        suicide("%s failed: %s", __func__, strerror(errno));
-}
-
-// XXX: Remove dead code.
-#if 0
-static void epoll_del(int fd)
-{
-    struct epoll_event ev;
-    ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
-    ev.data.fd = fd;
-    int r = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &ev);
-    if (r == -1)
-        suicide("epoll_del failed %s", strerror(errno));
-}
-#endif
-
 /* Writes a new resolv.conf based on the information we have received. */
 static void write_resolve_conf(void)
 {
@@ -358,8 +336,8 @@ void do_ifch_work(void)
 
     ifchd_client_init();
 
-    ep_add(pToIfchR);
+    epoll_add(epollfd, pToIfchR);
-    ep_add(signalFd);
+    epoll_add(epollfd, signalFd);
 
     for (;;) {
         int r = epoll_wait(epollfd, events, 2, -1);

ndhc/ndhc.c

@@ -49,6 +49,7 @@
 #include <pwd.h>
 #include <grp.h>
 
+#include "ndhc.h"
 #include "ndhc-defines.h"
 #include "config.h"
 #include "state.h"
@@ -124,6 +125,27 @@ static void show_usage(void)
     exit(EXIT_SUCCESS);
 }
 
+static void setup_signals_ndhc(void)
+{
+    sigset_t mask;
+    sigemptyset(&mask);
+    sigaddset(&mask, SIGUSR1);
+    sigaddset(&mask, SIGUSR2);
+    sigaddset(&mask, SIGCHLD);
+    sigaddset(&mask, SIGPIPE);
+    sigaddset(&mask, SIGTERM);
+    if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
+        suicide("sigprocmask failed");
+    if (cs.signalFd >= 0) {
+        epoll_del(cs.epollFd, cs.signalFd);
+        close(cs.signalFd);
+    }
+    cs.signalFd = signalfd(-1, &mask, SFD_NONBLOCK);
+    if (cs.signalFd < 0)
+        suicide("signalfd failed");
+    epoll_add(cs.epollFd, cs.signalFd);
+}
+
 static void signal_dispatch(void)
 {
     int t;
@@ -203,9 +225,9 @@ static void do_ndhc_work(void)
     if (enforce_seccomp_ndhc())
         log_line("ndhc seccomp filter cannot be installed");
 
-    setup_signals_ndhc(&cs);
+    setup_signals_ndhc();
 
-    epoll_add(&cs, cs.nlFd);
+    epoll_add(cs.epollFd, cs.nlFd);
     set_listen_raw(&cs);
     nowts = curms();
     goto jumpstart;
@@ -262,6 +284,7 @@ jumpstart:
 
 char chroot_dir[MAX_PATH_LENGTH] = "";
 char resolv_conf_d[MAX_PATH_LENGTH] = "";
+static char pidfile[MAX_PATH_LENGTH] = PID_FILE_DEFAULT;
 static uid_t ndhc_uid = 0;
 static gid_t ndhc_gid = 0;
 int pToNdhcR;
@@ -317,6 +340,22 @@ static void ndhc_main(void) {
     do_ndhc_work();
 }
 
+void background(void)
+{
+    static char called;
+    if (!called) {
+        called = 1;  // Do not fork again.
+        if (daemon(0, 0) == -1) {
+            perror("fork");
+            exit(EXIT_SUCCESS);
+        }
+    }
+    if (file_exists(pidfile, "w") == -1) {
+        log_line("Cannot open pidfile for write!");
+    } else
+        write_pid(pidfile);
+}
+
 int main(int argc, char **argv)
 {
     static const struct option arg_options[] = {

ndhc/ndhc.h

@@ -37,4 +37,6 @@ extern int pToNdhcW;
 extern char chroot_dir[MAX_PATH_LENGTH];
 extern char resolv_conf_d[MAX_PATH_LENGTH];
 
+extern void background(void);
+
 #endif /* NJK_NDHC_NDHC_H_ */

ndhc/state.c

@@ -36,6 +36,7 @@
 #include "arp.h"
 #include "options.h"
 #include "log.h"
+#include "ndhc.h"
 #include "sys.h"
 #include "random.h"
 
@@ -299,7 +300,7 @@ static void selecting_timeout(struct client_state_t *cs, long long nowts)
         if (client_config.background_if_no_lease) {
             log_line("No lease, going to background.");
             cs->init = 0;
-            background(cs);
+            background();
         } else if (client_config.abort_if_no_lease) {
             log_line("No lease, failing.");
             exit(EXIT_FAILURE);

ndhc/sys.c

@@ -31,74 +31,30 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
-#include <signal.h>
 #include <sys/epoll.h>
 #include <sys/signalfd.h>
+#include "sys.h"
 #include "config.h"
 #include "log.h"
-#include "pidfile.h"
-#include "sys.h"
 
-char pidfile[MAX_PATH_LENGTH] = PID_FILE_DEFAULT;
+void epoll_add(int epfd, int fd)
-
-void setup_signals_ndhc(struct client_state_t *cs)
-{
-    sigset_t mask;
-    sigemptyset(&mask);
-    sigaddset(&mask, SIGUSR1);
-    sigaddset(&mask, SIGUSR2);
-    sigaddset(&mask, SIGCHLD);
-    sigaddset(&mask, SIGPIPE);
-    sigaddset(&mask, SIGTERM);
-    if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
-        suicide("sigprocmask failed");
-    if (cs->signalFd >= 0) {
-        epoll_del(cs, cs->signalFd);
-        close(cs->signalFd);
-    }
-    cs->signalFd = signalfd(-1, &mask, SFD_NONBLOCK);
-    if (cs->signalFd < 0)
-        suicide("signalfd failed");
-    epoll_add(cs, cs->signalFd);
-}
-
-// @cs can be NULL
-void background(struct client_state_t *cs)
-{
-    static char called;
-    if (!called) {
-        called = 1;  // Do not fork again.
-        if (daemon(0, 0) == -1) {
-            perror("fork");
-            exit(EXIT_SUCCESS);
-        }
-        if (cs)
-            setup_signals_ndhc(cs);
-    }
-    if (file_exists(pidfile, "w") == -1) {
-        log_line("Cannot open pidfile for write!");
-    } else
-        write_pid(pidfile);
-}
-
-void epoll_add(struct client_state_t *cs, int fd)
 {
     struct epoll_event ev;
     int r;
     ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
     ev.data.fd = fd;
-    r = epoll_ctl(cs->epollFd, EPOLL_CTL_ADD, fd, &ev);
+    r = epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev);
     if (r == -1)
         suicide("epoll_add failed %s", strerror(errno));
 }
 
-void epoll_del(struct client_state_t *cs, int fd)
+void epoll_del(int epfd, int fd)
 {
     struct epoll_event ev;
     int r;
     ev.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLHUP;
     ev.data.fd = fd;
-    r = epoll_ctl(cs->epollFd, EPOLL_CTL_DEL, fd, &ev);
+    r = epoll_ctl(epfd, EPOLL_CTL_DEL, fd, &ev);
     if (r == -1)
         suicide("epoll_del failed %s", strerror(errno));
 }

ndhc/sys.h

@@ -39,11 +39,7 @@ static inline unsigned long long curms()
     return ts.tv_sec * 1000ULL + ts.tv_nsec / 1000000ULL;
 }
 
-extern char pidfile[MAX_PATH_LENGTH];
+extern void epoll_add(int epfd, int fd);
-
+extern void epoll_del(int epfd, int fd);
-void setup_signals_ndhc(struct client_state_t *cs);
-void background(struct client_state_t *cs);
-void epoll_add(struct client_state_t *cs, int fd);
-void epoll_del(struct client_state_t *cs, int fd);
 
 #endif /* SYS_H_ */