Update daemon.cc and add pidfile to miavd arguments.

1 files changed, 113 insertions, 57 deletions

diff --git a/src/daemon.cc b/src/daemon.cc
index 84ad8d9..2826484 100644
--- a/src/daemon.cc
+++ b/src/daemon.cc
@@ -3,7 +3,7 @@
  *            daemon.cc
  *
  *  Thu Jun  9 10:27:59 CEST 2005
- *  Copyright  2005 Bent Bisballe
+ *  Copyright  2005 Bent Bisballe Nyeng
  *  deva@aasimon.org
  ****************************************************************************/
 
@@ -22,7 +22,6 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
-
 #include "daemon.h"
 
 #include <sys/stat.h>
@@ -30,6 +29,8 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
 
 // For getgrent and getgrent
 #include <sys/types.h>
@@ -39,81 +40,136 @@
 // For strcmp
 #include <string.h>
 
+// Resolve a group's name or id into a numeric gid
+static gid_t get_gid(const char *grp)
+{
+  char *eptr;
+  gid_t xid = strtoul(grp, &eptr, 10);
+  struct group *gr;
+  errno = 0;      // Per getgrnam(3) and getgrgid(3) manual page
+  if(!*eptr)
+    gr = getgrgid(xid);
+  else
+    gr = getgrnam(grp);
+  return !gr ? 0 : gr->gr_gid;
+}
+
+// Resolve a user's name or id into a numeric uid with associated gid
+static uid_t get_uid(const char *usr, gid_t *gid)
+{
+  char *eptr;
+  uid_t xid = strtoul(usr, &eptr, 10);
+  struct passwd *pw;
+  errno = 0;      // Per getpwnam(3) and getpwuid(3) manual page
+  if(!*eptr)
+    pw = getpwuid(xid);
+  else
+    pw = getpwnam(usr);
+  if(!pw)
+    return 0;
+  if(!gid)
+    *gid = pw->pw_gid;
+  return pw->pw_uid;
+}
+
 Daemon::Daemon()
 {}
 
 Daemon::~Daemon()
 {}
 
-int Daemon::run(const char *user, const char* group, bool foreground)
+int Daemon::run(const char *user, const char* group, bool detach,
+                std::string pidfile)
 {
-  int f;
-  int fd;
-
-  // Fetch user id
-  int uid = -1;
-  struct passwd *p = getpwent();
-  while(p) {
-    if(strcmp(p->pw_name, user) == 0) uid = p->pw_uid;
-    p = getpwent();
-  }
-  if(uid == -1) {
-    fprintf(stderr, "Could not find user \"%s\" in /etc/passwd file.\n", user);
+  // Fetch user and group IDs
+  gid_t gid = 0;
+  uid_t uid = 0;
+  if(user && *user) {
+    uid = get_uid(user, &gid);
+    if(errno) {
+      fprintf(stderr, "Could resolve user \"%s\"", user);
+      perror("");
+    }
   }
 
-  // Fetch group id
-  int gid = -1;
-  struct group *g = getgrent();
-  while(g) {
-    if(strcmp(g->gr_name, group) == 0) gid = g->gr_gid;
-    g = getgrent();
-  }
-  if(gid == -1) {
-    fprintf(stderr, "Could not find group \"%s\" in /etc/group file.\n", group);
+  if(group && *group) {
+    gid = get_gid(group);
+    if(errno) {
+      fprintf(stderr, "Could not resolve group \"%s\"", group);
+      perror("");
+    }
   }
 
-  if(chdir("/") == -1) fprintf(stderr, "Could not chdir to '/'.\n");
   umask(0);
 
-  if(!foreground) {
-    f = fork();
-    switch(f) {
-    case -1: // Fork error
-      perror("Fork in daemon.cc");
-      return 1;
-    case 0:  // Forked child
-      break;
-    default: // Parent
-      return 0;
+  /*
+  if(pidfile != "" ) {
+    FILE *fp = fopen(pidfile.c_str(), "r");
+    if(fp != NULL) {
+      fclose(fp);
+      fprintf(stderr, "Could not write pid file \"%s\""
+              " - file already exists.\n",
+              pidfile.c_str());
+      return -1;
     }
   }
+  */
 
-  // Switch to given group
-  if(setgid(gid) != 0) {
-    fprintf(stderr, "Failed to change to group \"%s\" (gid: %d), quitting.\n", group, gid);
-    perror("");
-    fprintf(stderr, "Runnning daemon as current group\n");
+  if(detach) {
+    if(daemon(0, 0) == -1) { 
+      perror("");
+      return -1; 
+    }
   }
-  
-  // Switch to given user
-  if(setuid(uid) != 0) {
-    fprintf(stderr, "Failed to change to user \"%s\" (uid: %d), quitting.\n", user, uid);
-    perror("");
-    fprintf(stderr, "Runnning daemon as current user\n");
+
+  if(pidfile != "" ) {
+    pid_t pid = getpid();
+
+    FILE *fp = fopen(pidfile.c_str(), "w");
+    if(fp == NULL) {
+      fprintf(stderr, "Could not write pid file \"%s\"", pidfile.c_str());
+      perror("");
+      return -1;
+    } else {
+      fprintf(fp, "%lu", (unsigned long int)pid);
+      fclose(fp);
+    }
+  }
+
+  if(gid) {
+    // Switch to given group
+    if(setgid(gid) != 0) {
+      fprintf(stderr, "Failed to change to group \"%s\" (gid: %d).\n",
+              group, gid);
+      perror("");
+      fprintf(stderr, "Runnning daemon as current group\n");
+    }
   }
-  
-  // Redirect stdin, stdout and stderr to /dev/null
-  fd = open("/dev/null", O_NOCTTY | O_RDWR, 0666);
-  
-  dup2(0, fd);
-  dup2(1, fd);
-  dup2(2, fd);
     
+  if(uid) {
+    // Switch to given user
+    if(setuid(uid) != 0) {
+      fprintf(stderr, "Failed to change to user \"%s\" (uid: %d).\n",
+              user, uid);
+      perror("");
+      fprintf(stderr, "Runnning daemon as current user\n");
+    }
+  }
+
   setsid();
 
   signal (SIGTERM, SIG_IGN);
-  if(!foreground) signal (SIGINT, SIG_IGN);
-  signal (SIGHUP, SIG_IGN);
-  
-  return daemon_main();
+
+  //signal (SIGHUP, SIG_IGN);
+
+  // Don't disable Ctrl+c when running in foreground.
+  //if(detach) signal (SIGINT, SIG_IGN);
+
+  int ret = daemon_main();
+
+  if(pidfile != "") {
+    unlink(pidfile.c_str());
+  }
+
+  return ret;
 }