BSD 1 development

Work on file s6/syswatch.c

Synthesized-from: 1bsd

diff --git a/s6/syswatch.c b/s6/syswatch.c
new file mode 100644 (file)
index 0000000..d956af9
--- /dev/null
+++ b/s6/syswatch.c
@@ -0,0 +1,186 @@
+#
+/*
+ * syswatch - login-logout monitoring
+ *
+ * Author: Howard Katseff UCB May/August 1977
+ *
+ * Syswatch monitors all logins and logouts on the system.
+ * It is a companion routine to watch which monitors specific
+ * users.  The difference between these two routines is that
+ * the linked list stuff in watch has been abolished here in favor
+ * of a simpler scheme.
+ *
+ * ROOTDEV and NULLDEV are for determining when a user's tty has
+ * been chfile'd to /dev/null, in which case, the user has logged
+ * out and is probably no longer interested in the results of
+ * this program.
+ *
+ * This check will not work on non-UCB type UNIX'es.
+ * The check should be changed, or the syswatch killed explicitly.
+ */
+
+#define DLATENCY 15
+#define ROOTSYS ((5<<8) | 8)
+#define NULLDEV ((8<<8) | 2)
+
+int lastuser,valid;
+int zero[2];
+char *who_file "/etc/utmp";
+char *nil 0177777;
+
+
+struct t_entry {
+       char name[10];
+       char tty;
+       int time[2];
+       int valid;
+} people[128], newpeople[128];
+
+struct utmp {
+       char    Xname[10];
+       char    Xtty;
+       char    pad1;
+       int     ltime[2];
+       int     pad2;
+};
+
+main(ct,av)
+       char **av;
+{
+       register i;
+       register char *cp,*cp2;
+       int *p,pid,LATENCY;
+       LATENCY = DLATENCY;
+       p = -2;
+       if (pid=fork())
+       {
+               printf("%d\n",pid);
+               exit(0);
+       }
+       signal(2,1);
+       signal(3,1);
+       build();
+       for (i=0;i<128;++i) assign(people[i].name, newpeople[i].name);
+       for (;;)
+       {
+               execute();
+               sleep(LATENCY);
+       }
+}
+
+execute()
+{
+       register i;
+       int buf[18];
+       if (fstat(1, buf)) exit(0);
+       if (buf[0] == ROOTSYS && buf[6] == NULLDEV) exit(0);
+       valid++;
+       build();
+       for (i=0;i<128;++i)
+       {
+               if (!dcmp(newpeople[i].time,people[i].time))
+               {
+                       report(i);
+                       assign(people[i].name, newpeople[i].name);
+               }
+       }
+}
+
+build()
+{
+       register fd,i;
+       struct utmp line;
+       if ((fd=open(who_file,0)) < 0)
+       {
+               perror(who_file);
+               exit(1);
+       }
+       for (i=0;i<128;++i) newpeople[i].time[0] = newpeople[i].time[1] = 0;
+       while (getuser(fd,&line))
+       {
+               i = line.Xtty;
+               newpeople[i].valid = valid;
+               copy(line.Xname, newpeople[i].name);
+               newpeople[i].tty = i;
+               newpeople[i].time[0] = line.ltime[0];
+               newpeople[i].time[1] = line.ltime[1];
+       }
+       close(fd);
+}
+
+assign(l,r)
+       struct t_entry *l,*r;
+{
+       copy(r->name, l->name);
+       l->tty = r->tty;
+       l->time[0] = r->time[0];
+       l->time[1] = r->time[1];
+       l->valid++;
+}
+
+getuser(f,w)
+       struct utmp *w;
+{
+       register c;
+       char buf[16];
+       c = read(f,buf,16);
+       if (c != 16) return(0);
+       for (c=0;c<8;++c) w->Xname[c] = (buf[c] == 040 ? 0 : buf[c]);
+       w->Xname[8] = 0;
+       w->Xtty = buf[8];
+       if (w->Xname[0] == 0)
+       {
+               w->ltime[0] = w->ltime[1] = 0;
+               return(16);
+       }
+       w->ltime[0] = ctoi(buf[11],buf[10]);
+       w->ltime[1] = ctoi(buf[13],buf[12]);
+       return(16);
+}
+
+copy(c1,c2)
+       char *c1,*c2;
+{
+       while (*c2++ = *c1++);
+}
+
+equal(left,right)
+       char *left,*right;
+{
+       while (*left && *right)
+       {
+               if (*left != *right) return(0);
+               ++left;
+               ++right;
+       }
+       return(*left == *right);
+}
+
+dcmp(a,b)
+       int a[],b[];
+{
+       return(a[0]==b[0] && a[1]==b[1]);
+}
+
+ctoi(a,b)
+       char a,b;
+{
+       return(((a & 0377) << 8) | (b & 0377));
+}
+
+report(t)
+       char t;
+{
+       if (dcmp(people[t].time, zero))
+       {
+               printf("%s on tty%c %s",newpeople[t].name,t,ctime(newpeople[t].ltime));
+               return;
+       }
+       if (dcmp(newpeople[t].time,zero))
+       {
+               printf("%s on tty%c logged out.\n",people[t].name,t);
+               return;
+       }
+       printf("%s on tty%c logged out.\n",people[t].name,t);
+       printf("%s on tty%c %s",newpeople[t].name,t,ctime(newpeople[t].ltime));
+}