Added transition.c

diff --git a/utils/transition.c b/utils/transition.c
new file mode 100644 (file)
index 0000000..07718a2
--- /dev/null
+++ b/utils/transition.c
@@ -0,0 +1,275 @@
+/* transition.c
+ *
+ * This utility will aid in a transition from a CobraMUSH running in one
+ * directory to one running in a different directory, without disconnecting
+ * users.
+ *
+ * To use this:
+ *   Shell:
+ *     gcc -o transition transition.c -DTARGET="/path/to/new/game/directory"
+ *     cp transition /path/to/old/game/directory
+ *     cd /path/to/old/game/directory
+ *     rm netmush
+ *     ln -s transition netmush
+ *   Game:
+ *     @shutdown/reboot
+ *   Shell:
+ *     cp reboot.db /path/to/new/game/directory
+ *     cp data/* /path/to/new/game/directory/data
+ *   Make sure that the new game directory is ready to run.  This includes
+ *   a working netmush link and a suitably matched mush.cnf.
+ *   Shell:
+ *     kill -USR1 pid_of_this_program  (use -USR2 to cancel, but first
+ *       replace the netmush link with one to netmud)
+ *   When the restart is complete, check the game to be sure that everything
+ *   worked.
+ */
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef TARGET
+#error Compile with -DTARGET="/path/to/new/game/directory"
+#endif
+
+#define RDBF_SCREENSIZE 0x1
+#define RDBF_TTYPE 0x2
+#define RDBF_PUEBLO_CHECKSUM 0x4
+#define RDBF_SU_EXIT_PATH 0x10000
+
+#define BUFFER_LEN 1024
+
+struct desc {
+  struct desc *next;
+  int fd;
+};
+
+int sock;
+int maxd;
+struct desc *dlist;
+int signaled;
+int start_new;
+
+int load_reboot_db(void);
+void signal_usr1(int);
+void signal_usr2(int);
+int getref(FILE *);
+const char *getstring_noalloc(FILE *);
+int safe_chr(char, char *, char **);
+void tell_one_guy(int, const char *);
+void tell_everyone(const char *);
+void deal_with_everyone(void);
+
+int main(int argc, char *argv[]) {
+  struct desc *cur;
+
+  signaled = 0;
+  start_new = 0;
+  signal(SIGUSR1, signal_usr1);
+  signal(SIGUSR2, signal_usr2);
+
+  if(!load_reboot_db()) {
+    fprintf(stderr, "unable to load db\n");
+    exit(1);
+  }
+
+  printf("MUSH Server Transition Utility\n\n");
+
+  printf("sock = %d\nmaxd = %d\nfds =", sock, maxd);
+  for(cur = dlist; cur; cur = cur->next)
+    printf(" %d", cur->fd);
+  printf("\n");
+
+  printf("To trigger the action, kill -USR1 %d\n", getpid());
+  printf("This will chdir to %s and run netmush mush.cnf\n", TARGET);
+  printf("You will need to copy reboot.db into the new location for this to work\n");
+  printf("To cancel the action and run netmush mush.cnf in the current\ndirectory, kill -USR2 %d\n", getpid());
+  printf("Of course, you will want to make sure that netmush points to a MUSH binary\ninstead of to this program before you do that.\n");
+
+  tell_everyone("GAME: Beginning transition to new server\n");
+
+  while(!signaled)
+    deal_with_everyone();
+
+  if(start_new) {
+    tell_everyone("GAME: Starting new server\n");
+    chdir(TARGET);
+  } else {
+    tell_everyone("GAME: Operation cancelled.  The old server will be restarted.\n");
+  }
+
+  execl("netmush", "netmush", "mush.cnf", NULL);
+}
+
+void tell_one_guy(int fd, const char *str) {
+  write(fd, str, strlen(str));
+}
+
+void tell_everyone(const char *str) {
+  struct desc *cur;
+
+  for(cur = dlist; cur; cur = cur->next)
+    tell_one_guy(cur->fd, str);
+}
+
+void deal_with_everyone(void) {
+  fd_set inset;
+  struct timeval timeout;
+  struct desc *cur;
+
+  FD_ZERO(&inset);
+  timeout.tv_sec = 1;
+  timeout.tv_usec = 0;
+
+  for(cur = dlist; cur; cur = cur->next)
+    FD_SET(cur->fd, &inset);
+
+  select(maxd, &inset, NULL, NULL, &timeout);
+
+  for(cur = dlist; cur; cur = cur->next)
+    if(FD_ISSET(cur->fd, &inset))
+      tell_one_guy(cur->fd, "GAME: Server transition in progress, input ignored\n");
+}
+
+void signal_usr1(int sig __attribute__ ((__unused__))) {
+  signaled = 1;
+  start_new = 1;
+}
+
+void signal_usr2(int sig __attribute__ ((__unused__))) {
+  signaled = 1;
+}
+
+int load_reboot_db(void) {
+  FILE *f;
+  struct desc *cur;
+  int val;
+  char c;
+  long flags = 0, connflags;
+  int exit_path;
+
+  f = fopen("reboot.db", "r");
+  if (!f)
+    return 0;
+
+  c = getc(f);                  /* Skip the V */
+  if (c == 'V') {
+    flags = getref(f);
+  } else {
+    fclose(f);
+    return 0;
+  }
+
+  maxd = 0;
+  sock = getref(f);
+  val = getref(f);
+  if (val > maxd)
+    maxd = val;
+
+  dlist = NULL;
+  while ((val = getref(f)) != 0) {
+    cur = (struct desc *) malloc(sizeof(struct desc));
+
+    cur->fd = val;
+    getref(f); /* connected_at */
+    getref(f); /* hide */
+    getref(f); /* cmds */
+    getref(f); /* idle_total */
+    getref(f); /* unidle_times */
+    getref(f); /* player */
+    getref(f); /* last_time */
+    getstring_noalloc(f); /* output_prefix */
+    getstring_noalloc(f); /* output_suffix */
+    getstring_noalloc(f); /* addr */
+    getstring_noalloc(f); /* ip */
+    getstring_noalloc(f); /* doing */
+    connflags = getref(f);
+    if(flags & RDBF_SCREENSIZE) {
+      getref(f); /* width */
+      getref(f); /* height */
+    }
+    if(flags & RDBF_TTYPE)
+      getstring_noalloc(f); /* ttype */
+    if(flags & RDBF_PUEBLO_CHECKSUM)
+      getstring_noalloc(f); /* checksum */
+    if(flags & RDBF_SU_EXIT_PATH)
+      for(exit_path = getref(f); exit_path >= 0; exit_path = getref(f))
+        ;
+
+    cur->next = dlist;
+    dlist = cur;
+  }
+
+  fclose(f);
+
+  return 1;
+}
+
+int getref(FILE *f) {
+  static char buf[BUFFER_LEN];
+  if (!fgets(buf, sizeof(buf), f)) {
+    fprintf(stderr, "unexpected eof\n");
+    exit(1);
+  }
+  return strtol(buf, NULL, 10);
+}
+
+const char *getstring_noalloc(FILE *f) {
+  static char buf[BUFFER_LEN];
+  char *p;
+  int c;
+
+  p = buf;
+  c = fgetc(f);
+  if (c == EOF) {
+    fprintf(stderr, "unexpected eof\n");
+    exit(1);
+  } else if (c != '"') {
+    for (;;) {
+      if ((c == '\0') || (c == EOF) ||
+          ((c == '\n') && ((p == buf) || (p[-1] != '\r')))) {
+        *p = '\0';
+        return buf;
+      }
+      safe_chr(c, buf, &p);
+      c = fgetc(f);
+    }
+  } else {
+    for (;;) {
+      c = fgetc(f);
+      if (c == '"') {
+        /* It's a closing quote if it's followed by \r or \n */
+        c = fgetc(f);
+        if (c == '\r') {
+          /* Get a possible \n, too */
+          if ((c = fgetc(f)) != '\n')
+            ungetc(c, f);
+        } else if (c != '\n')
+          ungetc(c, f);
+        *p = '\0';
+        return buf;
+      } else if (c == '\\') {
+        c = fgetc(f);
+      }
+      if ((c == '\0') || (c == EOF)) {
+        *p = '\0';
+        return buf;
+      }
+      safe_chr(c, buf, &p);
+    }
+  }
+}
+
+int safe_chr(char c, char *buf, char **bufp) {
+  /* adds a character to a string, being careful not to overflow buffer */
+
+  if ((*bufp - buf >= BUFFER_LEN - 1))
+    return 1;
+
+  *(*bufp)++ = c;
+  return 0;
+}
+