diod: always run in the foreground

Problem: diod puts itself in the background by default, but this can be confusing and unexpected when running the service manually. In fact, given that systemd can manage daemons running in the foreground, it is probably no longer useful at all. Drop the --foreground option and never daemonize. Update tests.
chaos · Jan 19, 2025 · 3dc9363 · 3dc9363
1 parent cc881bd
commit 3dc9363
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Showing 5 changed files with 2 additions and 56 deletions.
diff --git a/src/cmd/diod.c b/src/cmd/diod.c
@@ -14,9 +14,6 @@
 #include "config.h"
 #endif
 #include <poll.h>
-#ifndef _BSD_SOURCE
-#define _BSD_SOURCE         /* daemon () */
-#endif
 #include <stdlib.h>
 #include <stdint.h>
 #include <sys/types.h>
@@ -57,7 +54,6 @@
 
 typedef enum { SRV_FILEDES, SRV_SOCKTEST, SRV_NORMAL } srvmode_t;
 
-static void          _daemonize (void);
 static void          _setrlimit (void);
 static void          _become_user (char *name, uid_t uid, int realtoo);
 static void          _service_run (srvmode_t mode, int rfdno, int wfdno);
@@ -66,10 +62,9 @@ static void          _service_run (srvmode_t mode, int rfdno, int wfdno);
 #define NR_OPEN         1048576 /* works on RHEL 5 x86_64 arch */
 #endif
 
-static const char *options = "fr:w:d:l:t:e:Eo:u:SL:nHpc:NU:s";
+static const char *options = "r:w:d:l:t:e:Eo:u:SL:nHpc:NU:s";
 
 static const struct option longopts[] = {
-    {"foreground",         no_argument,        0, 'f'},
     {"rfdno",              required_argument,  0, 'r'},
     {"wfdno",              required_argument,  0, 'w'},
     {"debug",              required_argument,  0, 'd'},
@@ -96,7 +91,6 @@ usage()
 {
     fprintf (stderr,
 "Usage: diod [OPTIONS]\n"
-"   -f,--foreground         do not fork and disassociate with tty\n"
 "   -r,--rfdno              service connected client on read file descriptor\n"
 "   -w,--wfdno              service connected client on write file descriptor\n"
 "   -l,--listen IP:PORT     set interface to listen on (multiple -l allowed)\n"
@@ -149,9 +143,6 @@ main(int argc, char **argv)
     opterr = 0;
     while ((c = getopt_long (argc, argv, options, longopts, NULL)) != -1) {
         switch (c) {
-            case 'f':   /* --foreground */
-                diod_conf_set_foreground (1);
-                break;
             case 'r':   /* --rfdno */
                 mode = SRV_FILEDES;
                 rfdno = strtoul (optarg, NULL, 10);
@@ -339,26 +330,6 @@ _setrlimit (void)
 
 }
 
-/* Create run directory if it doesn't exist and chdir there.
- * Disassociate from parent's controlling tty.
- * Exit on error.
- */
-static void
-_daemonize (void)
-{
-    char rdir[PATH_MAX];
-
-    snprintf (rdir, sizeof(rdir), "%s/run/diod", X_LOCALSTATEDIR);
-    if (mkdir (rdir, 0755) < 0 && errno != EEXIST) {
-        msg ("failed to find/create %s, running out of /tmp", rdir);
-        snprintf (rdir, sizeof(rdir), "/tmp");
-    }
-    if (chdir (rdir) < 0)
-        err_exit ("chdir %s", rdir);
-    if (daemon (1, 0) < 0)
-        err_exit ("daemon");
-}
-
 /**
  ** Service startup
  **/
@@ -599,11 +570,6 @@ _service_run (srvmode_t mode, int rfdno, int wfdno)
         }
     }
 
-    if (!diod_conf_get_foreground () && mode != SRV_FILEDES)
-        _daemonize (); /* implicit fork - no pthreads before this */
-    if (!diod_conf_get_foreground () && mode != SRV_FILEDES)
-        diod_log_set_dest (diod_conf_get_logdest ());
-
     /* drop root */
     if (euid == 0) {
         if (diod_conf_get_allsquash ())

diff --git a/src/libdiod/diod_conf.c b/src/libdiod/diod_conf.c
@@ -56,7 +56,6 @@
 /* ro_mask values to protect attribute from overwrite by config file */
 #define RO_DEBUGLEVEL           0x00000001
 #define RO_NWTHREADS            0x00000002
-#define RO_FOREGROUND           0x00000004
 #define RO_AUTH_REQUIRED        0x00000008
 #define RO_RUNASUID             0x00000010
 #define RO_USERDB               0x00000020
@@ -77,7 +76,6 @@
 typedef struct {
     int          debuglevel;
     int          nwthreads;
-    int          foreground;
     int          auth_required;
     int          hostname_lookup;
     int          statfs_passthru;
@@ -165,7 +163,6 @@ diod_conf_init (void)
 {
     config.debuglevel = DFLT_DEBUGLEVEL;
     config.nwthreads = DFLT_NWTHREADS;
-    config.foreground = DFLT_FOREGROUND;
     config.auth_required = DFLT_AUTH_REQUIRED;
     config.hostname_lookup = DFLT_HOSTNAME_LOOKUP;
     config.statfs_passthru = DFLT_STATFS_PASSTHRU;
@@ -242,16 +239,6 @@ void diod_conf_set_nwthreads (int i)
     config.ro_mask |= RO_NWTHREADS;
 }
 
-/* foreground - run daemon in foreground
- */
-int diod_conf_get_foreground (void) { return config.foreground; }
-int diod_conf_opt_foreground (void) { return config.ro_mask & RO_FOREGROUND; }
-void diod_conf_set_foreground (int i)
-{
-    config.foreground = i;
-    config.ro_mask |= RO_FOREGROUND;
-}
-
 /* auth_required - whether to accept unauthenticated attaches
  */
 int diod_conf_get_auth_required (void) { return config.auth_required; }

diff --git a/src/libdiod/diod_conf.h b/src/libdiod/diod_conf.h
@@ -16,7 +16,6 @@
 #define DFLT_DEBUGLEVEL         0
 #define DFLT_NWTHREADS          16
 #define DFLT_MAXMMAP            0
-#define DFLT_FOREGROUND         0
 #define DFLT_AUTH_REQUIRED      1
 #define DFLT_HOSTNAME_LOOKUP    1
 #define DFLT_STATFS_PASSTHRU    0
@@ -50,10 +49,6 @@ int     diod_conf_get_nwthreads (void);
 int     diod_conf_opt_nwthreads (void);
 void    diod_conf_set_nwthreads (int i);
 
-int     diod_conf_get_foreground (void);
-int     diod_conf_opt_foreground (void);
-void    diod_conf_set_foreground (int i);
-
 int     diod_conf_get_auth_required (void);
 int     diod_conf_opt_auth_required (void);
 void    diod_conf_set_auth_required (int i);

diff --git a/src/libdiod/test/configfile.c b/src/libdiod/test/configfile.c
@@ -61,7 +61,6 @@ exports = {\n\
     is (s, path, "configpath is %s", path);
     ok (diod_conf_get_debuglevel () == DFLT_DEBUGLEVEL, "debuglevel is default");
     ok (diod_conf_get_nwthreads () == DFLT_NWTHREADS, "nwthreads is default");
-    ok (diod_conf_get_foreground () == DFLT_FOREGROUND, "foreground is default");
     ok (diod_conf_get_auth_required () == DFLT_AUTH_REQUIRED,
         "auth_required is default");
     ok (diod_conf_get_hostname_lookup () == DFLT_HOSTNAME_LOOKUP,
@@ -156,7 +155,6 @@ exports = { \"/g/g1\" }\n";
     is (s, path, "configpath is %s", path);
     ok (diod_conf_get_debuglevel () == DFLT_DEBUGLEVEL, "debuglevel is default");
     ok (diod_conf_get_nwthreads () == 64, "nwthreads is 64");
-    ok (diod_conf_get_foreground () == DFLT_FOREGROUND, "foreground is default");
     ok (diod_conf_get_auth_required () != 0, "auth_required is true");
     ok (diod_conf_get_hostname_lookup () == DFLT_HOSTNAME_LOOKUP,
         "hostname_lookup is default");

diff --git a/tests/misc/t15 b/tests/misc/t15
@@ -12,7 +12,7 @@ bg_test ()
 TEST=$(basename $0 | cut -d- -f1)
 sockfile=$(mktemp)
 bg_test $sockfile &
-${MISC_SRCDIR}/memcheck ${TOP_BUILDDIR}/src/cmd/diod -c /dev/null -n -f -e ctl -l $sockfile -s >$TEST.out 2>&1
+${MISC_SRCDIR}/memcheck ${TOP_BUILDDIR}/src/cmd/diod -c /dev/null -n -e ctl -l $sockfile -s >$TEST.out 2>&1
 diff ${MISC_SRCDIR}/$TEST.exp $TEST.out >$TEST.diff
 rm -f $sockfile
 wait %1