X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/1011401782de9fc44636e88f4b3e4bceb0de4e04..91370169de7f552f3a54e5ef9e079a202a5efbfa:/server/server.c

diff --git a/server/server.c b/server/server.c
index a09025e..67b1fdc 100644
--- a/server/server.c
+++ b/server/server.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of DisOrder.
- * Copyright (C) 2004, 2005, 2006, 2007 Richard Kettlewell
+ * Copyright (C) 2004-2008 Richard Kettlewell
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -67,6 +67,10 @@
 #include "unicode.h"
 #include "cookies.h"
 #include "base64.h"
+#include "hash.h"
+#include "mime.h"
+#include "sendmail.h"
+#include "wstat.h"
 
 #ifndef NONCE_SIZE
 # define NONCE_SIZE 16
@@ -118,8 +122,13 @@ struct conn {
   char *cookie;
   /** @brief Connection rights */
   rights_type rights;
+  /** @brief Next connection */
+  struct conn *next;
 };
 
+/** @brief Linked list of connections */
+static struct conn *connections;
+
 static int reader_callback(ev_source *ev,
 			   ev_reader *reader,
 			   void *ptr,
@@ -129,6 +138,16 @@ static int reader_callback(ev_source *ev,
 
 static const char *noyes[] = { "no", "yes" };
 
+/** @brief Remove a connection from the connection list */
+static void remove_connection(struct conn *c) {
+  struct conn **cc;
+
+  for(cc = &connections; *cc && *cc != c; cc = &(*cc)->next)
+    ;
+  if(*cc)
+    *cc = c->next;
+}
+
 /** @brief Called when a connection's writer fails or is shut down
  *
  * If the connection still has a raeder that is cancelled.
@@ -154,6 +173,7 @@ static int writer_error(ev_source attribute((unused)) *ev,
   }
   c->w = 0;
   ev_report(ev);
+  remove_connection(c);
   return 0;
 }
 
@@ -173,6 +193,7 @@ static int reader_error(ev_source attribute((unused)) *ev,
   c->w = 0;
   c->r = 0;
   ev_report(ev);
+  remove_connection(c);
   return 0;
 }
 
@@ -339,7 +360,7 @@ static int c_rescan(struct conn *c,
 		    char attribute((unused)) **vec,
 		    int attribute((unused)) nvec) {
   info("S%x rescan by %s", c->tag, c->who);
-  trackdb_rescan(c->ev);
+  trackdb_rescan(c->ev, 1/*check*/);
   sink_writes(ev_writer_sink(c->w), "250 initiated rescan\n");
   return 1;				/* completed */
 }
@@ -435,10 +456,10 @@ static int c_user(struct conn *c,
     c->who = vec[0];
     c->rights = rights;
     /* currently we only bother logging remote connections */
-    if(strcmp(host, "local")) {
+    if(strcmp(host, "local"))
       info("S%x %s connected from %s", c->tag, vec[0], host);
+    else
       c->rights |= RIGHT__LOCAL;
-    }
     sink_writes(ev_writer_sink(c->w), "230 OK\n");
     return 1;
   }
@@ -785,6 +806,7 @@ static int logging_reader_callback(ev_source attribute((unused)) *ev,
       c->w = 0;
     }
     c->r = 0;
+    remove_connection(c);
   }
   return 0;
 }
@@ -977,9 +999,18 @@ static int c_nop(struct conn *c,
 static int c_new(struct conn *c,
 		 char **vec,
 		 int nvec) {
-  char **tracks = trackdb_new(0, nvec > 0 ? atoi(vec[0]) : INT_MAX);
+  int max, n;
+  char **tracks;
 
+  if(nvec > 0)
+    max = atoi(vec[0]);
+  else
+    max = INT_MAX;
+  if(max <= 0 || max > config->new_max)
+    max = config->new_max;
+  tracks = trackdb_new(0, max);
   sink_printf(ev_writer_sink(c->w), "253 New track list follows\n");
+  n = 0;
   while(*tracks) {
     sink_printf(ev_writer_sink(c->w), "%s%s\n",
 		**tracks == '.' ? "." : "", *tracks);
@@ -1029,10 +1060,10 @@ static int c_cookie(struct conn *c,
   c->who = user;
   c->cookie = vec[0];
   c->rights = rights;
-  if(strcmp(host, "local")) {
+  if(strcmp(host, "local"))
     info("S%x %s connected with cookie from %s", c->tag, user, host);
+  else
     c->rights |= RIGHT__LOCAL;
-  }
   /* Response contains username so client knows who they are acting as */
   sink_printf(ev_writer_sink(c->w), "232 %s\n", quoteutf8(user));
   return 1;
@@ -1085,26 +1116,50 @@ static int c_adduser(struct conn *c,
 static int c_deluser(struct conn *c,
 		     char **vec,
 		     int attribute((unused)) nvec) {
-  if(trackdb_deluser(vec[0]))
+  struct conn *d;
+
+  if(trackdb_deluser(vec[0])) {
     sink_writes(ev_writer_sink(c->w), "550 Cannot delete user\n");
-  else
-    sink_writes(ev_writer_sink(c->w), "250 User deleted\n");
+    return 1;
+  }
+  /* Zap connections belonging to deleted user */
+  for(d = connections; d; d = d->next)
+    if(!strcmp(d->who, vec[0]))
+      d->rights = 0;
+  sink_writes(ev_writer_sink(c->w), "250 User deleted\n");
   return 1;
 }
 
 static int c_edituser(struct conn *c,
 		      char **vec,
 		      int attribute((unused)) nvec) {
+  struct conn *d;
+
   /* RIGHT_ADMIN can do anything; otherwise you can only set your own email
    * address and password. */
   if((c->rights & RIGHT_ADMIN)
      || (!strcmp(c->who, vec[0])
 	 && (!strcmp(vec[1], "email")
 	     || !strcmp(vec[1], "password")))) {
-    if(trackdb_edituserinfo(vec[0], vec[1], vec[2]))
+    if(trackdb_edituserinfo(vec[0], vec[1], vec[2])) {
       sink_writes(ev_writer_sink(c->w), "550 Failed to change setting\n");
-    else
-      sink_writes(ev_writer_sink(c->w), "250 OK\n");
+      return 1;
+    }
+    if(!strcmp(vec[1], "password")) {
+      /* Zap all connections for this user after a password change */
+      for(d = connections; d; d = d->next)
+	if(!strcmp(d->who, vec[0]))
+	  d->rights = 0;
+    } else if(!strcmp(vec[1], "rights")) {
+      /* Update rights for this user */
+      rights_type r;
+
+      if(parse_rights(vec[2], &r, 1))
+	for(d = connections; d; d = d->next)
+	  if(!strcmp(d->who, vec[0]))
+	    d->rights = r;
+    }
+    sink_writes(ev_writer_sink(c->w), "250 OK\n");
   } else {
     error(0, "%s attempted edituser but lacks required rights", c->who);
     sink_writes(ev_writer_sink(c->w), "510 Restricted to administrators\n");
@@ -1154,6 +1209,16 @@ static int c_users(struct conn *c,
   return 1;				/* completed */
 }
 
+/** @brief Base64 mapping table for confirmation strings
+ *
+ * This is used with generic_to_base64() and generic_base64().  We cannot use
+ * the MIME table as that contains '+' and '=' which get quoted when
+ * URL-encoding.  (The CGI still does the URL encoding but it is desirable to
+ * avoid it being necessary.)
+ */
+static const char confirm_base64_table[] =
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/.*";
+
 static int c_register(struct conn *c,
 		      char **vec,
 		      int attribute((unused)) nvec) {
@@ -1166,7 +1231,8 @@ static int c_register(struct conn *c,
   buf = xmalloc_noptr(bufsize);
   offset = byte_snprintf(buf, bufsize, "%s;", vec[0]);
   gcry_randomize(buf + offset, CONFIRM_SIZE, GCRY_STRONG_RANDOM);
-  cs = mime_to_base64((uint8_t *)buf, offset + CONFIRM_SIZE);
+  cs = generic_to_base64((uint8_t *)buf, offset + CONFIRM_SIZE,
+			 confirm_base64_table);
   if(trackdb_adduser(vec[0], vec[1], config->default_rights, vec[2], cs))
     sink_writes(ev_writer_sink(c->w), "550 Cannot create user\n");
   else
@@ -1179,20 +1245,126 @@ static int c_confirm(struct conn *c,
 		     int attribute((unused)) nvec) {
   size_t nuser;
   char *user, *sep;
+  rights_type rights;
+  const char *host;
 
-  if(!(user = mime_base64(vec[0], &nuser))
+  /* Get some kind of peer identifcation */
+  if(!(host = connection_host(c))) {
+    sink_writes(ev_writer_sink(c->w), "530 Authentication failure\n");
+    return 1;
+  }
+  if(!(user = generic_base64(vec[0], &nuser, confirm_base64_table))
      || !(sep = memchr(user, ';', nuser))) {
     sink_writes(ev_writer_sink(c->w), "550 Malformed confirmation string\n");
     return 1;
   }
   *sep = 0;
-  if(trackdb_confirm(user, vec[0]))
+  if(trackdb_confirm(user, vec[0], &rights))
     sink_writes(ev_writer_sink(c->w), "550 Incorrect confirmation string\n");
-  else
-    sink_writes(ev_writer_sink(c->w), "250 OK\n");
+  else {
+    c->who = user;
+    c->cookie = 0;
+    c->rights = rights;
+    if(strcmp(host, "local"))
+      info("S%x %s confirmed from %s", c->tag, user, host);
+    else
+      c->rights |= RIGHT__LOCAL;
+    /* Response contains username so client knows who they are acting as */
+    sink_printf(ev_writer_sink(c->w), "232 %s\n", quoteutf8(user));
+  }
   return 1;
 }
- 
+
+static int sent_reminder(ev_source attribute((unused)) *ev,
+			 pid_t attribute((unused)) pid,
+			 int status,
+			 const struct rusage attribute((unused)) *rusage,
+			 void *u) {
+  struct conn *const c = u;
+
+  /* Tell the client what went down */ 
+  if(!status) {
+    sink_writes(ev_writer_sink(c->w), "250 OK\n");
+  } else {
+    error(0, "reminder subprocess %s", wstat(status));
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+  }
+  /* Re-enable this connection */
+  ev_reader_enable(c->r);
+  return 0;
+}
+
+static int c_reminder(struct conn *c,
+		      char **vec,
+		      int attribute((unused)) nvec) {
+  struct kvp *k;
+  const char *password, *email, *text, *encoding, *charset, *content_type;
+  const time_t *last;
+  time_t now;
+  pid_t pid;
+  
+  static hash *last_reminder;
+
+  if(!config->mail_sender) {
+    error(0, "cannot send password reminders because mail_sender not set");
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+    return 1;
+  }
+  if(!(k = trackdb_getuserinfo(vec[0]))) {
+    error(0, "reminder for user '%s' who does not exist", vec[0]);
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+    return 1;
+  }
+  if(!(email = kvp_get(k, "email"))
+     || !strchr(email, '@')) {
+    error(0, "user '%s' has no valid email address", vec[0]);
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+    return 1;
+  }
+  if(!(password = kvp_get(k, "password"))
+     || !*password) {
+    error(0, "user '%s' has no password", vec[0]);
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+    return 1;
+  }
+  /* Rate-limit reminders.  This hash is bounded in size by the number of
+   * users.  If this is actually a problem for anyone then we can periodically
+   * clean it. */
+  if(!last_reminder)
+    last_reminder = hash_new(sizeof (time_t));
+  last = hash_find(last_reminder, vec[0]);
+  time(&now);
+  if(last && now < *last + config->reminder_interval) {
+    error(0, "sent a password reminder to '%s' too recently", vec[0]);
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+    return 1;
+  }
+  /* Send the reminder */
+  /* TODO this should be templatized and to some extent merged with
+   * the code in act_register() */
+  byte_xasprintf((char **)&text,
+"Someone requested that you be sent a reminder of your DisOrder password.\n"
+"Your password is:\n"
+"\n"
+"  %s\n", password);
+  if(!(text = mime_encode_text(text, &charset, &encoding)))
+    fatal(0, "cannot encode email");
+  byte_xasprintf((char **)&content_type, "text/plain;charset=%s",
+		 quote822(charset, 0));
+  pid = sendmail_subprocess("", config->mail_sender, email,
+			    "DisOrder password reminder",
+			    encoding, content_type, text);
+  if(pid < 0) {
+    sink_writes(ev_writer_sink(c->w), "550 Cannot send a reminder email\n");
+    return 1;
+  }
+  hash_add(last_reminder, vec[0], &now, HASH_INSERT_OR_REPLACE);
+  info("sending a passsword reminder to user '%s'", vec[0]);
+  /* We can only continue when the subprocess finishes */
+  ev_child(c->ev, pid, 0, sent_reminder, c);
+  return 0;
+}
+
 static const struct command {
   /** @brief Command name */
   const char *name;
@@ -1246,6 +1418,7 @@ static const struct command {
   { "recent",         0, 0,       c_recent,         RIGHT_READ },
   { "reconfigure",    0, 0,       c_reconfigure,    RIGHT_ADMIN },
   { "register",       3, 3,       c_register,       RIGHT_REGISTER|RIGHT__LOCAL },
+  { "reminder",       1, 1,       c_reminder,       RIGHT__LOCAL },
   { "remove",         1, 1,       c_remove,         RIGHT_REMOVE__MASK },
   { "rescan",         0, 0,       c_rescan,         RIGHT_RESCAN },
   { "resolve",        1, 1,       c_resolve,        RIGHT_READ },
@@ -1369,6 +1542,7 @@ static int reader_callback(ev_source attribute((unused)) *ev,
       ev_writer_close(c->w);
       c->w = 0;
     }
+    remove_connection(c);
   }
   return 0;
 }