First attempt at hibernation code. It needs more work around the XXXXs, but first I want arma to review the basic approach while I meditate on how to fix them.

svn:r2649

doc/TODO

@@ -23,8 +23,8 @@ ARMA    - arma claims
    o Add a log handler that sends stuff to syslog.
    o Deprecate unofficial configuration abbrevs; make official abbrevs
      only official on the command line.
-   - per-month byte allowances.
+   l per-month byte allowances.
-N    - Based on bandwidth and per-month allowance, choose a
+N    . Based on bandwidth and per-month allowance, choose a
        window within month to be up.  Stay up until allowance is
        used.  Adjust next month's window based on outcome.  Hibernate
        when we're not up.
@@ -39,7 +39,7 @@ R  . bandwidth buckets for write as well as read.
    . Pure C tor_resolve
      o Implement it; socks4a only is fine for now.
 N    - Make it build on win32
-N/R  - Make it not link with zlib and openssl.
+     o Make it not link with zlib and openssl.
 N  - RPMs
 N  - Windows installer
    - Review website; make important info more prominent.

src/or/config.c

@@ -112,6 +112,8 @@ static config_var_t config_vars[] = {
   OBSOLETE("LinkPadding"),
   VAR("MaxConn",             UINT,     MaxConn),
   VAR("MaxOnionsPending",    UINT,     MaxOnionsPending),
+  VAR("MonthlyAccountingStart",UINT,   AccountingStart),
+  VAR("AccountingMaxKB",     UINT,     AccountingMaxKB),
   VAR("Nickname",            STRING,   Nickname),
   VAR("NewCircuitPeriod",    UINT,     NewCircuitPeriod),
   VAR("NumCpus",             UINT,     NumCpus),
@@ -384,7 +386,7 @@ config_assign(or_options_t *options, struct config_line_t *list)
       return -1;
     list = list->next;
   }
-
+  
   return 0;
 }
 
@@ -962,6 +964,15 @@ getconfig(int argc, char **argv, or_options_t *options)
     result = -1;
   }
 
+  if (options->AccountingStart < 0 || options->AccountingStart > 31) {
+    log(LOG_WARN,"Monthy accounting must start on a day of the month, and no months have %d days.",
+        options->AccountingStart);
+    result = -1;
+  } else if (options->AccountingStart > 28) {
+    log(LOG_WARN,"Not every month has %d days.",options->AccountingStart);
+    result = -1;
+  }
+
   if (options->HttpProxy) { /* parse it now */
     if (parse_addr_port(options->HttpProxy, NULL,
                         &options->HttpProxyAddr, &options->HttpProxyPort) < 0) {

src/or/connection.c

@@ -869,9 +869,9 @@ static int connection_read_to_buf(connection_t *conn) {
 
   if(result > 0 && !is_local_IP(conn->addr)) { /* remember it */
     rep_hist_note_bytes_read(result, time(NULL));
+    connection_read_bucket_decrement(conn, result);
   }
 
-  connection_read_bucket_decrement(conn, result);
   return 0;
 }
 
@@ -1001,10 +1001,9 @@ int connection_handle_write(connection_t *conn) {
 
   if(result > 0 && !is_local_IP(conn->addr)) { /* remember it */
     rep_hist_note_bytes_written(result, now);
+    global_write_bucket -= result;
   }
 
-  global_write_bucket -= result;
-
   if(!connection_wants_to_flush(conn)) { /* it's done flushing */
     if(connection_finished_flushing(conn) < 0) {
       /* already marked */

src/or/hibernate.c

@@ -33,23 +33,17 @@ time_t hibernate_timeout = 0;
 
 /** Returns 1 if the bandwidth soft limit has been reached, else 0. */
 static int hibernate_soft_limit_reached(void) {
-
+  return accounting_soft_limit_reached();
-
-  return 0;
 }
 
 /** Returns 1 if the bandwidth hard limit has been reached, else 0. */
 static int hibernate_hard_limit_reached(void) {
-
+  return accounting_hard_limit_reached();
-
-  return 0;
 }
 
 /** Return the time when we should stop being dormant. */
 static time_t hibernate_calc_wakeup_time(void) {
-
+  return accounting_get_wakeup_time();
-
-  return 0;
 }
 
 /** Called when we get a SIGINT, or when bandwidth soft limit

src/or/main.c

@@ -13,6 +13,12 @@
 
 static void dumpstats(int severity); /* log stats */
 static int init_from_config(int argc, char **argv);
+static int read_bandwidth_usage(void);
+static int record_bandwidth_usage(time_t now);
+static void configure_accounting(time_t now);
+static time_t start_of_accounting_period_after(time_t now);
+static time_t start_of_accounting_period_containing(time_t now);
+static void accounting_set_wakeup_time(void);
 
 /********* START VARIABLES **********/
 
@@ -34,6 +40,15 @@ long stats_n_seconds_uptime = 0;
 /** When do we next download a directory? */
 static time_t time_to_fetch_directory = 0;
 
+/** How many bytes have we read/written in this accounting interval? */
+static uint64_t stats_n_bytes_read_in_interval = 0;
+static uint64_t stats_n_bytes_written_in_interval = 0;
+/** When did this accounting interval start? */
+static time_t interval_start_time = 0;
+/** When will this accounting interval end? */
+static time_t interval_end_time = 0;
+/** How far into the accounting interval should we hibernate? */
+static time_t interval_wakeup_time = 0;
 
 /** Array of all open connections; each element corresponds to the element of
  * poll_array in the same position.  The first nfds elements are valid. */
@@ -372,6 +387,237 @@ void directory_has_arrived(time_t now) {
   }
 }
 
+/* ************
+ * Functions for bandwidth accounting.
+ * ************/
+static time_t start_of_accounting_period_containing(time_t now)
+{
+  struct tm *tm;
+  /* Only months are supported. */
+  tm = gmtime(&now);
+  /* If this is before the Nth, we want the Nth of last month. */
+  if (tm->tm_mday < options.AccountingStart) {
+    if (--tm->tm_mon < 0) {
+      tm->tm_mon = 11;
+      --tm->tm_year;
+    }
+  }
+  /* Otherwise, the month and year are correct.*/
+
+  tm->tm_mday = options.AccountingStart;
+  tm->tm_hour = 0;
+  tm->tm_min = 0;
+  tm->tm_sec = 0;
+  return tor_timegm(tm);
+}
+static time_t start_of_accounting_period_after(time_t now)
+{
+  time_t start;
+  struct tm *tm;
+  start = start_of_accounting_period_containing(now);
+
+  tm = gmtime(&start);
+  if (++tm->tm_mon > 11) {
+    tm->tm_mon = 0;
+    ++tm->tm_year;
+  }
+  return tor_timegm(tm);
+}
+
+static void configure_accounting(time_t now)
+{
+  if (!interval_start_time)
+    read_bandwidth_usage(); /* XXXX009 check warning? */
+  if (!interval_start_time ||
+      start_of_accounting_period_after(interval_start_time) <= now) {
+    /* We start a new interval. */
+    log_fn(LOG_INFO, "Starting new accounting interval.");
+    interval_start_time = start_of_accounting_period_containing(now);
+    interval_end_time = start_of_accounting_period_after(interval_start_time);
+    stats_n_bytes_read_in_interval = 0;
+    stats_n_bytes_written_in_interval = 0;
+  } if (interval_start_time ==
+        start_of_accounting_period_containing(interval_start_time)) {
+    log_fn(LOG_INFO, "Continuing accounting interval.");
+    /* We are in the interval we thought we were in. Do nothing.*/
+  } else {
+    /* XXXX009 We are in an incompatible interval; we must have
+     * changed our configuration.  Do we reset the interval, or
+     * what? */
+    log_fn(LOG_INFO, "Mismatched accounting interval.");
+  }
+  accounting_set_wakeup_time();
+}
+
+static INLINE int time_to_record_bandwidth_usage(time_t now)
+{
+  /* Note every 5 minutes */
+#define NOTE_INTERVAL (5*60)
+  /* Or every 20 megabytes */
+#define NOTE_BYTES 20*(1024*1024)
+  static uint64_t last_read_bytes_noted = 0;
+  static uint64_t last_written_bytes_noted = 0;
+  static time_t last_time_noted = 0;
+
+  if ((options.AccountingMaxKB || 1)&&
+      (last_time_noted + NOTE_INTERVAL <= now ||
+       last_read_bytes_noted + NOTE_BYTES <= stats_n_bytes_read_in_interval ||
+       last_written_bytes_noted + NOTE_BYTES <=
+           stats_n_bytes_written_in_interval ||
+       (interval_end_time && interval_end_time <= now))) {
+    last_time_noted = now;
+    last_read_bytes_noted = stats_n_bytes_read_in_interval;
+    last_written_bytes_noted = stats_n_bytes_written_in_interval;
+    return 1;
+  }
+  return 0;
+}
+
+void accounting_set_wakeup_time(void)
+{
+  struct tm *tm;
+  char buf[ISO_TIME_LEN+1];
+  char digest[DIGEST_LEN];
+  crypto_digest_env_t *d;
+  int n_days_in_interval;
+
+  format_iso_time(buf, interval_start_time);
+  crypto_pk_get_digest(get_identity_key(), digest);
+
+  d = crypto_new_digest_env();
+  crypto_digest_add_bytes(d, buf, ISO_TIME_LEN);
+  crypto_digest_add_bytes(d, digest, DIGEST_LEN);
+  crypto_digest_get_digest(d, digest, DIGEST_LEN);
+  crypto_free_digest_env(d);
+
+  /* XXXX009 This logic is  wrong.  Instead of choosing randomly
+   * from the days in the interval, we should avoid days so close to the end
+   * that we won't use up all our bandwidth.  This could potentially waste
+   * 50% of all donated bandwidth.
+   */
+  tm = gmtime(&interval_start_time);
+  if (++tm->tm_mon > 11) { tm->tm_mon = 0; ++tm->tm_year; }
+  n_days_in_interval = (tor_timegm(tm)-interval_start_time+1)/(24*60*60);
+
+  while (((unsigned char)digest[0]) > n_days_in_interval)
+    crypto_digest(digest, digest, DIGEST_LEN);
+
+  interval_wakeup_time = interval_start_time +
+    24*60*60 * (unsigned char)digest[0];
+}
+
+static int record_bandwidth_usage(time_t now)
+{
+  char buf[128];
+  char fname[512];
+  char *cp = buf;
+
+  *cp++ = '0';
+  *cp++ = ' ';
+  format_iso_time(cp, interval_start_time);
+  cp += ISO_TIME_LEN;
+  *cp++ = ' ';
+  format_iso_time(cp, now);
+  cp += ISO_TIME_LEN;
+  tor_snprintf(cp, sizeof(buf)-ISO_TIME_LEN*2-3,
+               " "U64_FORMAT" "U64_FORMAT"\n",
+               U64_PRINTF_ARG(stats_n_bytes_read_in_interval),
+               U64_PRINTF_ARG(stats_n_bytes_written_in_interval));
+  tor_snprintf(fname, sizeof(fname), "%s/bw_accounting",
+               get_data_directory(&options));
+
+  return write_str_to_file(fname, buf, 0);
+}
+
+static int read_bandwidth_usage(void)
+{
+  char *s = NULL;
+  char fname[512];
+  time_t scratch_time;
+
+  /*
+  if (!options.AccountingMaxKB)
+    return 0;
+  */
+  tor_snprintf(fname, sizeof(fname), "%s/bw_accounting",
+               get_data_directory(&options));
+  if (!(s = read_file_to_str(fname, 0))) {
+    return 0;
+  }
+  /* version, space, time, space, time, space, bw, space, bw, nl. */
+  if (strlen(s) < ISO_TIME_LEN*2+6) {
+    log_fn(LOG_WARN,
+           "Recorded bandwidth usage file seems truncated or corrupted");
+    goto err;
+  }
+  if (s[0] != '0' || s[1] != ' ') {
+    log_fn(LOG_WARN, "Unrecognized version on bandwidth usage file");
+    goto err;
+  }
+  if (parse_iso_time(s+2, &interval_start_time)) {
+    log_fn(LOG_WARN, "Error parsing bandwidth usage start time.");
+    goto err;
+  }
+  if (s[ISO_TIME_LEN+2] != ' ') {
+    log_fn(LOG_WARN, "Expected space after start time.");
+    goto err;
+  }
+  if (parse_iso_time(s+ISO_TIME_LEN+3, &scratch_time)) {
+    log_fn(LOG_WARN, "Error parsing bandwidth usage last-written time");
+    goto err;
+  }
+  if (s[ISO_TIME_LEN+3+ISO_TIME_LEN] != ' ') {
+    log_fn(LOG_WARN, "Expected space after last-written time.");
+    goto err;
+  }
+  if (sscanf(s+ISO_TIME_LEN*2+4, U64_FORMAT" "U64_FORMAT,
+             U64_SCANF_ARG(&stats_n_bytes_read_in_interval),
+             U64_SCANF_ARG(&stats_n_bytes_written_in_interval))<2) {
+    log_fn(LOG_WARN, "Error reading bandwidth usage.");
+    goto err;
+  }
+
+  tor_free(s);
+  accounting_set_wakeup_time();
+  return 0;
+ err:
+  tor_free(s);
+  return -1;
+}
+
+int accounting_hard_limit_reached(void)
+{
+  uint64_t hard_limit = options.AccountingMaxKB<<10;
+  if (!hard_limit)
+    return 0;
+  return stats_n_bytes_read_in_interval >= hard_limit
+    || stats_n_bytes_written_in_interval >= hard_limit;
+}
+
+int accounting_soft_limit_reached(void)
+{
+  uint64_t soft_limit = (uint64_t) ((options.AccountingMaxKB<<10) * .99);
+  if (!soft_limit)
+    return 0;
+  return stats_n_bytes_read_in_interval >= soft_limit
+    || stats_n_bytes_written_in_interval >= soft_limit;
+}
+
+time_t accounting_get_wakeup_time(void)
+{
+  if (interval_wakeup_time > time(NULL))
+    return interval_wakeup_time;
+  else
+    /*XXXX009 this means that callers must check for wakeup time again
+    * at the start of the next interval.  Not right! */
+    return interval_end_time;
+}
+
+int accounting_should_hibernate(void)
+{
+  return accouting_hard_limit_reached() || interval_wakeup_time > time(NULL);
+}
+
 /** Perform regular maintenance tasks for a single connection.  This
  * function gets run once per second per connection by run_housekeeping.
  */
@@ -439,19 +685,14 @@ static int decide_if_publishable_server(time_t now) {
   if(!options.ORPort)
     return 0;
 
-
   /* XXX008 for now, you're only a server if you're a server */
   return server_mode();
 
-
   /* here, determine if we're reachable */
   if(0) { /* we've recently failed to reach our IP/ORPort from the outside */
     return 0;
   }
 
-
-
-
   if(bw < MIN_BW_TO_PUBLISH_DESC)
     return 0;
   if(options.AuthoritativeDir)
@@ -539,6 +780,18 @@ static void run_scheduled_events(time_t now) {
      * XXXX them at all. */
   }
 
+  /** 1c. If we have to change the accounting interval or record
+   * bandwidth used in this accounting interval, do so. */
+  if (now >= interval_end_time) {
+    configure_accounting(now);
+  }
+  if (time_to_record_bandwidth_usage(now)) {
+    if (record_bandwidth_usage(now)) {
+      log_fn(LOG_WARN, "Couldn't record bandwidth usage!");
+      /* XXXX009 should this exit? */
+    }
+  }
+
   /** 2. Every DirFetchPostPeriod seconds, we get a new directory and upload
    *    our descriptor (if we've passed our internal checks). */
   if(time_to_fetch_directory < now) {
@@ -647,7 +900,10 @@ static int prepare_for_poll(void) {
   /* Check how much bandwidth we've consumed, and increment the token
    * buckets. */
   stats_n_bytes_read += stats_prev_global_read_bucket - global_read_bucket;
+  stats_n_bytes_read_in_interval += stats_prev_global_read_bucket - global_read_bucket;
   stats_n_bytes_written += stats_prev_global_write_bucket - global_write_bucket;
+  stats_n_bytes_written_in_interval += stats_prev_global_write_bucket - global_write_bucket;
+
   connection_bucket_refill(&now);
   stats_prev_global_read_bucket = global_read_bucket;
   stats_prev_global_write_bucket = global_write_bucket;
@@ -802,6 +1058,9 @@ static int do_main_loop(void) {
     return -1;
   }
 
+  /* Set up accounting */
+  configure_accounting(time(NULL));
+
   /* load the routers file, or assign the defaults. */
   if(router_reload_router_list()) {
     return -1;
@@ -983,16 +1242,11 @@ static void dumpstats(int severity) {
 
   if (stats_n_seconds_uptime)
     log(severity,
-#ifdef MS_WINDOWS
+        "Average bandwidth used: "U64_FORMAT"/%ld = %d bytes/sec", 
-        "Average bandwidth used: %I64u/%ld = %d bytes/sec", 
+        U64_PRINTF_ARG(stats_n_bytes_read),
-          stats_n_bytes_read,
-#else
-        "Average bandwidth used: %llu/%ld = %d bytes/sec",
-          (long long unsigned int)stats_n_bytes_read,
-#endif
         stats_n_seconds_uptime,
         (int) (stats_n_bytes_read/stats_n_seconds_uptime));
-
+  
   rep_hist_dump_stats(now,severity);
   rend_service_dump_stats(severity);
 }
@@ -1107,12 +1361,11 @@ static void do_list_fingerprint(void)
   if (!(k = get_identity_key())) {
     log_fn(LOG_ERR,"Error: missing identity key.");
     return;
-  }    
+  }
   if (crypto_pk_get_fingerprint(k, buf, 1)<0) {
     log_fn(LOG_ERR, "Error computing fingerprint");
     return;
   }
-  printf("%s %s\n", options.Nickname, buf);
 }
 
 #ifdef MS_WINDOWS_SERVICE

src/or/or.h

@@ -927,6 +927,12 @@ typedef struct {
   struct config_line_t *RedirectExit; /**< List of config lines for simple
                                        * addr/port redirection */
   smartlist_t *RedirectExitList; /**< List of exit_redirect_t */
+  int AccountingStart; /**< At what offset within the accounting interval
+                        * do we begin measuring?  (Currently only day-of-month
+                        * is supported.) */
+  int AccountingMaxKB; /**< How many KB do we allow per accounting
+                        * interval before hibernation?  0 for "never
+                        * hibernate." */
 } or_options_t;
 
 /* XXX are these good enough defaults? */
@@ -1264,6 +1270,11 @@ int proxy_mode(void);
 void handle_signals(int is_parent);
 void tor_cleanup(void);
 
+int accounting_hard_limit_reached(void);
+int accounting_soft_limit_reached(void);
+time_t accounting_get_wakeup_time(void);
+int accounting_should_hibernate(void);
+
 int tor_main(int argc, char *argv[]);
 
 /********************************* onion.c ***************************/