Implement bulletin facility

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301 USA */
+
+#include "pop3d.h"
+
+static char *bulletin_mbox_name;
+static char *bulletin_db_name;
+
+void
+set_bulletin_db (char *file)
+{
+  bulletin_db_name = file;
+}
+
+static void
+close_bulletin_mailbox (mu_mailbox_t *pmbox)
+{
+  if (pmbox)
+    {
+      mu_mailbox_close (*pmbox);
+      mu_mailbox_destroy (pmbox);
+    }
+}
+
+static int
+open_bulletin_mailbox (mu_mailbox_t *pmbox)
+{
+  int status;
+  mu_mailbox_t tmbox;
+  
+  if ((status = mu_mailbox_create (&tmbox, bulletin_mbox_name)) != 0)
+    {
+      mu_error (_("Cannot create bulletin mailbox `%s': %s"),
+		bulletin_mbox_name, mu_strerror (status));
+      return 1;
+    }
+
+  if ((status = mu_mailbox_open (tmbox, MU_STREAM_RDWR|MU_STREAM_CREAT)) != 0)
+    {
+      mu_error (_("Cannot open bulletin mailbox `%s': %s"),
+		bulletin_mbox_name, mu_strerror (status));
+      return 1;
+    }
+  if (!pmbox)
+    close_bulletin_mailbox (&tmbox);
+  else
+    *pmbox = tmbox;
+  return 0;
+}
+
+int
+set_bulletin_source (char *source)
+{
+  int rc;
+
+  bulletin_mbox_name = source;
+  rc = open_bulletin_mailbox (NULL);
+  if (rc)
+    bulletin_mbox_name = NULL;
+  return rc;
+}
+
+static int
+read_popbull_file (size_t *pnum)
+{
+  int rc = 1;
+  FILE *fp;
+  char *filename = mu_tilde_expansion ("~/.popbull", "/", auth_data->dir);
+  
+  if (!filename)
+    return 1;
+  fp = fopen (filename, "r");
+  if (fp)
+    {
+      char buf[128];
+      char *p = fgets (buf, sizeof buf, fp);
+      if (p)
+	{
+	  *pnum = strtoul (buf, &p, 0);
+	  rc = *p && !isspace (*p);
+	}
+      fclose (fp);
+    }
+  return rc;
+}
+
+static int
+write_popbull_file (size_t num)
+{
+  int rc = 1;
+  FILE *fp;
+  char *filename = mu_tilde_expansion ("~/.popbull", "/", auth_data->dir);
+  
+  if (!filename)
+    return 1;
+  fp = fopen (filename, "w");
+  if (fp)
+    {
+      fprintf (fp, "%s\n", mu_umaxtostr (0, num));
+      fclose (fp);
+      rc = 0;
+    }
+  return rc;
+}
+
+#ifdef USE_DBM
+int
+read_bulletin_db (size_t *pnum)
+{
+  DBM_FILE db;
+  DBM_DATUM key, data;
+  int rc;
+  char sbuf[128];
+  char *bufptr;
+  char *buf = NULL;
+  size_t s;
+  char *p;
+  
+  rc = mu_dbm_open (bulletin_db_name, &db, MU_STREAM_READ, 0600);
+  if (rc)
+    {
+      mu_error (_("Unable to open bulletin db for reading: %s"),
+		mu_strerror (errno));
+      return rc;
+    }
+
+  memset (&key, 0, sizeof key);
+  memset (&data, 0, sizeof data);
+
+  MU_DATUM_PTR(key) = username;
+  MU_DATUM_SIZE(key) = strlen (username);
+
+  rc = mu_dbm_fetch (db, key, &data);
+  mu_dbm_close (db);
+
+  if (rc)
+    {
+      mu_error (_("Cannot fetch bulletin db data: %s"),
+		mu_strerror (errno));
+      return 1;
+    }
+
+  s = MU_DATUM_SIZE(data);
+  if (s < sizeof sbuf)
+    bufptr = sbuf;
+  else
+    {
+      buf = malloc (s + 1);
+      if (!buf)
+	{
+	  mu_error("%s", mu_strerror (errno));
+	  return 1;
+	}
+      bufptr = buf;
+    }
+
+  memcpy (bufptr, MU_DATUM_PTR(data), s);
+  bufptr[s] = 0;
+  mu_dbm_datum_free(&data);
+  
+  rc = 1;
+  *pnum = strtoul (bufptr, &p, 0);
+  if (*p == 0)
+    rc = 0;
+  else
+    {
+#ifdef QPOPPER_COMPAT
+      if (s == sizeof long)
+	{
+	  long n;
+
+	  n = *(long*)MU_DATUM_PTR(data);
+	  if (n >= 0)
+	    {
+	      syslog (LOG_INFO,
+		      _("assuming bulletin database is in qpopper format"));
+	      *pnum = n;
+	      rc = 0;
+	    }
+	}
+      else
+#endif /* QPOPPER_COMPAT */
+	{
+	  mu_error (_("Wrong bulletin database format for `%s'"),
+		    username);
+	}
+    }
+  
+  free (buf);
+  return rc;
+}
+
+int
+write_bulletin_db (size_t num)
+{
+  DBM_FILE db;
+  DBM_DATUM key, data;
+  int rc;
+  char *p;
+  
+  rc = mu_dbm_open (bulletin_db_name, &db, MU_STREAM_RDWR, 0600);
+  if (rc)
+    {
+      mu_error (_("Unable to open bulletin db for writing: %s"),
+		mu_strerror (errno));
+      return rc;
+    }
+
+  memset (&key, 0, sizeof key);
+  memset (&data, 0, sizeof data);
+
+  MU_DATUM_PTR(key) = username;
+  MU_DATUM_SIZE(key) = strlen (username);
+  p = mu_umaxtostr (0, num);
+  MU_DATUM_PTR(data) = p;
+  MU_DATUM_SIZE(data) = strlen (p);
+
+  rc = mu_dbm_insert (db, key, data, 1);
+  if (rc)
+    mu_error (_("Cannot store datum in bulletin db"));
+
+  mu_dbm_close (db);
+  return rc;
+}
+#endif /* USE_DBM */
+      
+size_t
+get_last_delivered_num ()
+{
+  size_t num = 0;
+  
+#ifdef USE_DBM  
+  if (bulletin_db_name && read_bulletin_db (&num) == 0)
+    return num;
+#endif
+
+  read_popbull_file (&num);
+  return num;
+}
+
+void
+store_last_delivered_num (size_t num)
+{
+#ifdef USE_DBM  
+  if (bulletin_db_name && write_bulletin_db (num) == 0)
+    return;
+#endif
+  write_popbull_file (num);
+}
+
+void
+deliver_pending_bulletins ()
+{
+  mu_mailbox_t bull;
+  int rc;
+  size_t lastnum, total;
+
+  if (!bulletin_mbox_name)
+    return;
+  
+  rc = open_bulletin_mailbox (&bull);
+  if (rc)
+    return;
+  lastnum = get_last_delivered_num ();
+
+  mu_mailbox_messages_count (bull, &total);
+
+  syslog (LOG_DEBUG,
+	  "user %s, last bulletin %lu, total bulletins %lu",
+	  username, (unsigned long) lastnum, (unsigned long) total);
+	  
+  if (lastnum < total)
+    {
+      size_t i;
+      size_t count = total - lastnum;
+  
+      syslog (LOG_INFO,
+	      ngettext ("user %s: delivering %lu pending bulletin",
+			"user %s: delivering %lu pending bulletins",
+			count),
+	      username, (unsigned long) count);
+
+      for (i = lastnum + 1; i <= total; i++)
+	{
+	  int rc;
+	  mu_message_t msg;
+	  
+	  if ((rc = mu_mailbox_get_message (bull, i, &msg)) != 0)
+	    {
+	      mu_error (_("Cannot read bulletin %lu: %s"),
+			(unsigned long) i, mu_strerror (rc));
+	      break;
+	    }
+	
+	  if ((rc = mu_mailbox_append_message (mbox, msg)) != 0)
+	    {
+	      mu_error (_("Cannot append message %lu: %s"),
+			(unsigned long) i, mu_strerror (rc));
+	      break;
+	    }
+	}
+      store_last_delivered_num (i - 1);
+    }
+  close_bulletin_mailbox (&bull);
+}
+