text: /* Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "apr.h"
  #include "apr_strings.h"
  #include "apr_portable.h"
  #include "apr_lib.h"
  
  #define APR_WANT_STRFUNC
  #include "apr_want.h"
  
  #if APR_HAVE_SYS_TYPES_H
  #include <sys/types.h>
  #endif
  
  #include "ap_config.h"
  #include "httpd.h"
  #include "http_log.h"
  #include "http_main.h"
  #include "http_core.h"
  #include "http_config.h"
  #include "ap_mpm.h"
  
  #include "mpm.h"
  #include "scoreboard.h"
  
  AP_DECLARE_DATA scoreboard *ap_scoreboard_image = NULL;
  AP_DECLARE_DATA const char *ap_scoreboard_fname = NULL;
  AP_DECLARE_DATA int ap_extended_status = 0;
  AP_DECLARE_DATA int ap_mod_status_reqtail = 0;
  
  #if APR_HAS_SHARED_MEMORY
  
  #include "apr_shm.h"
  
  #ifndef WIN32
  static /* but must be exported to mpm_winnt */
  #endif
          apr_shm_t *ap_scoreboard_shm = NULL;
  
  #endif
  
  APR_HOOK_STRUCT(
      APR_HOOK_LINK(pre_mpm)
  )
  
  AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_mpm,
                            (apr_pool_t *p, ap_scoreboard_e sb_type),
                            (p, sb_type),OK,DECLINED)
  
  static APR_OPTIONAL_FN_TYPE(ap_proxy_lb_workers)
                                  *proxy_lb_workers;
  
  struct ap_sb_handle_t {
      int child_num;
      int thread_num;
  };
  
  static int server_limit, thread_limit, lb_limit;
  static apr_size_t scoreboard_size;
  
  /*
   * ToDo:
   * This function should be renamed to cleanup_shared
   * and it should handle cleaning up a scoreboard shared
   * between processes using any form of IPC (file, shared memory
   * segment, etc.). Leave it as is now because it is being used
   * by various MPMs.
   */
  static apr_status_t ap_cleanup_shared_mem(void *d)
  {
  #if APR_HAS_SHARED_MEMORY
      free(ap_scoreboard_image);
      ap_scoreboard_image = NULL;
      apr_shm_destroy(ap_scoreboard_shm);
  #endif
      return APR_SUCCESS;
  }
  
  AP_DECLARE(int) ap_calc_scoreboard_size(void)
  {
      ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &thread_limit);
      ap_mpm_query(AP_MPMQ_HARD_LIMIT_DAEMONS, &server_limit);
  
      if (!proxy_lb_workers)
          proxy_lb_workers = APR_RETRIEVE_OPTIONAL_FN(ap_proxy_lb_workers);
      if (proxy_lb_workers)
          lb_limit = proxy_lb_workers();
      else
          lb_limit = 0;
  
      scoreboard_size = sizeof(global_score);
      scoreboard_size += sizeof(process_score) * server_limit;
      scoreboard_size += sizeof(worker_score) * server_limit * thread_limit;
      if (lb_limit)
          scoreboard_size += sizeof(lb_score) * lb_limit;
  
      return scoreboard_size;
  }
  
  void ap_init_scoreboard(void *shared_score)
  {
      char *more_storage;
      int i;
  
      ap_calc_scoreboard_size();
      ap_scoreboard_image =
          calloc(1, sizeof(scoreboard) + server_limit * sizeof(worker_score *));
      more_storage = shared_score;
      ap_scoreboard_image->global = (global_score *)more_storage;
      more_storage += sizeof(global_score);
      ap_scoreboard_image->parent = (process_score *)more_storage;
      more_storage += sizeof(process_score) * server_limit;
      ap_scoreboard_image->servers =
          (worker_score **)((char*)ap_scoreboard_image + sizeof(scoreboard));
      for (i = 0; i < server_limit; i++) {
          ap_scoreboard_image->servers[i] = (worker_score *)more_storage;
          more_storage += thread_limit * sizeof(worker_score);
      }
      if (lb_limit) {
          ap_scoreboard_image->balancers = (lb_score *)more_storage;
          more_storage += lb_limit * sizeof(lb_score);
      }
      ap_assert(more_storage == (char*)shared_score + scoreboard_size);
      ap_scoreboard_image->global->server_limit = server_limit;
      ap_scoreboard_image->global->thread_limit = thread_limit;
      ap_scoreboard_image->global->lb_limit     = lb_limit;
  }
  
  /**
   * Create a name-based scoreboard in the given pool using the
   * given filename.
   */
  static apr_status_t create_namebased_scoreboard(apr_pool_t *pool,
                                                  const char *fname)
  {
  #if APR_HAS_SHARED_MEMORY
      apr_status_t rv;
  
      /* The shared memory file must not exist before we create the
       * segment. */
      apr_shm_remove(fname, pool); /* ignore errors */
  
      rv = apr_shm_create(&ap_scoreboard_shm, scoreboard_size, fname, pool);
      if (rv != APR_SUCCESS) {
          ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                       "unable to create or access scoreboard \"%s\" "
                       "(name-based shared memory failure)", fname);
          return rv;
      }
  #endif /* APR_HAS_SHARED_MEMORY */
      return APR_SUCCESS;
  }
  
  /* ToDo: This function should be made to handle setting up
   * a scoreboard shared between processes using any IPC technique,
   * not just a shared memory segment
   */
  static apr_status_t open_scoreboard(apr_pool_t *pconf)
  {
  #if APR_HAS_SHARED_MEMORY
      apr_status_t rv;
      char *fname = NULL;
      apr_pool_t *global_pool;
  
      /* We don't want to have to recreate the scoreboard after
       * restarts, so we'll create a global pool and never clean it.
       */
      rv = apr_pool_create(&global_pool, NULL);
      if (rv != APR_SUCCESS) {
          ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                       "Fatal error: unable to create global pool "
                       "for use with by the scoreboard");
          return rv;
      }
  
      /* The config says to create a name-based shmem */
      if (ap_scoreboard_fname) {
          /* make sure it's an absolute pathname */
          fname = ap_server_root_relative(pconf, ap_scoreboard_fname);
          if (!fname) {
              ap_log_error(APLOG_MARK, APLOG_CRIT, APR_EBADPATH, NULL,
                           "Fatal error: Invalid Scoreboard path %s",
                           ap_scoreboard_fname);
              return APR_EBADPATH;
          }
          return create_namebased_scoreboard(global_pool, fname);
      }
      else { /* config didn't specify, we get to choose shmem type */
          rv = apr_shm_create(&ap_scoreboard_shm, scoreboard_size, NULL,
                              global_pool); /* anonymous shared memory */
          if ((rv != APR_SUCCESS) && (rv != APR_ENOTIMPL)) {
              ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
                           "Unable to create or access scoreboard "
                           "(anonymous shared memory failure)");
              return rv;
          }
          /* Make up a filename and do name-based shmem */
          else if (rv == APR_ENOTIMPL) {
              /* Make sure it's an absolute pathname */
              ap_scoreboard_fname = DEFAULT_SCOREBOARD;
              fname = ap_server_root_relative(pconf, ap_scoreboard_fname);
  
              return create_namebased_scoreboard(global_pool, fname);
          }
      }
  #endif /* APR_HAS_SHARED_MEMORY */
      return APR_SUCCESS;
  }
  
  /* If detach is non-zero, this is a seperate child process,
   * if zero, it is a forked child.
   */
  apr_status_t ap_reopen_scoreboard(apr_pool_t *p, apr_shm_t **shm, int detached)
  {
  #if APR_HAS_SHARED_MEMORY
      if (!detached) {
          return APR_SUCCESS;
      }
      if (apr_shm_size_get(ap_scoreboard_shm) < scoreboard_size) {
          ap_log_error(APLOG_MARK, APLOG_CRIT, 0, NULL,
                       "Fatal error: shared scoreboard too small for child!");
          apr_shm_detach(ap_scoreboard_shm);
          ap_scoreboard_shm = NULL;
          return APR_EINVAL;
      }
      /* everything will be cleared shortly */
      if (*shm) {
          *shm = ap_scoreboard_shm;
      }
  #endif
      return APR_SUCCESS;
  }
  
  apr_status_t ap_cleanup_scoreboard(void *d)
  {
      if (ap_scoreboard_image == NULL) {
          return APR_SUCCESS;
      }
      if (ap_scoreboard_image->global->sb_type == SB_SHARED) {
          ap_cleanup_shared_mem(NULL);
      }
      else {
          free(ap_scoreboard_image->global);
          free(ap_scoreboard_image);
          ap_scoreboard_image = NULL;
      }
      return APR_SUCCESS;
  }
  
  /* Create or reinit an existing scoreboard. The MPM can control whether
   * the scoreboard is shared across multiple processes or not
   */
  int ap_create_scoreboard(apr_pool_t *p, ap_scoreboard_e sb_type)
  {
      int running_gen = 0;
      int i;
  #if APR_HAS_SHARED_MEMORY
      apr_status_t rv;
  #endif
  
      if (ap_scoreboard_image) {
          running_gen = ap_scoreboard_image->global->running_generation;
          ap_scoreboard_image->global->restart_time = apr_time_now();
          memset(ap_scoreboard_image->parent, 0,
                 sizeof(process_score) * server_limit);
          for (i = 0; i < server_limit; i++) {
              memset(ap_scoreboard_image->servers[i], 0,
                     sizeof(worker_score) * thread_limit);
          }
          /* Clean up the lb workers data */
          if (lb_limit) {
              memset(ap_scoreboard_image->balancers, 0,
                     sizeof(lb_score) * lb_limit);
          }
          return OK;
      }
  
      ap_calc_scoreboard_size();
  #if APR_HAS_SHARED_MEMORY
      if (sb_type == SB_SHARED) {
          void *sb_shared;
          rv = open_scoreboard(p);
          if (rv || !(sb_shared = apr_shm_baseaddr_get(ap_scoreboard_shm))) {
              return HTTP_INTERNAL_SERVER_ERROR;
          }
          memset(sb_shared, 0, scoreboard_size);
          ap_init_scoreboard(sb_shared);
      }
      else
  #endif
      {
          /* A simple malloc will suffice */
          void *sb_mem = calloc(1, scoreboard_size);
          if (sb_mem == NULL) {
              ap_log_error(APLOG_MARK, APLOG_CRIT, 0, NULL,
                           "(%d)%s: cannot allocate scoreboard",
                           errno, strerror(errno));
              return HTTP_INTERNAL_SERVER_ERROR;
          }
          ap_init_scoreboard(sb_mem);
      }
  
      ap_scoreboard_image->global->sb_type = sb_type;
      ap_scoreboard_image->global->running_generation = running_gen;
      ap_scoreboard_image->global->restart_time = apr_time_now();
  
      apr_pool_cleanup_register(p, NULL, ap_cleanup_scoreboard, apr_pool_cleanup_null);
  
      return OK;
  }
  
  /* Routines called to deal with the scoreboard image
   * --- note that we do *not* need write locks, since update_child_status
   * only updates a *single* record in place, and only one process writes to
   * a given scoreboard slot at a time (either the child process owning that
   * slot, or the parent, noting that the child has died).
   *
   * As a final note --- setting the score entry to getpid() is always safe,
   * since when the parent is writing an entry, it's only noting SERVER_DEAD
   * anyway.
   */
  
  AP_DECLARE(int) ap_exists_scoreboard_image(void)
  {
      return (ap_scoreboard_image ? 1 : 0);
  }
  
  AP_DECLARE(void) ap_increment_counts(ap_sb_handle_t *sb, request_rec *r)
  {
      worker_score *ws;
  
      if (!sb)
          return;
  
      ws = &ap_scoreboard_image->servers[sb->child_num][sb->thread_num];
  
  #ifdef HAVE_TIMES
      times(&ws->times);
  #endif
      ws->access_count++;
      ws->my_access_count++;
      ws->conn_count++;
      ws->bytes_served += r->bytes_sent;
      ws->my_bytes_served += r->bytes_sent;
      ws->conn_bytes += r->bytes_sent;
  }
  
  int find_child_by_pid(apr_proc_t *pid)
  {
      int i;
      int max_daemons_limit;
  
      ap_mpm_query(AP_MPMQ_MAX_DAEMONS, &max_daemons_limit);
  
      for (i = 0; i < max_daemons_limit; ++i) {
          if (ap_scoreboard_image->parent[i].pid == pid->pid) {
              return i;
          }
      }
  
      return -1;
  }
  
  AP_DECLARE(void) ap_create_sb_handle(ap_sb_handle_t **new_sbh, apr_pool_t *p,
                                       int child_num, int thread_num)
  {
      *new_sbh = (ap_sb_handle_t *)apr_palloc(p, sizeof(ap_sb_handle_t));
      (*new_sbh)->child_num = child_num;
      (*new_sbh)->thread_num = thread_num;
  }
  
  static void copy_request(char *rbuf, apr_size_t rbuflen, request_rec *r)
  {
      char *p;
  
      if (r->the_request == NULL) {
          apr_cpystrn(rbuf, "NULL", rbuflen);
          return; /* short circuit below */
      }
  
      if (r->parsed_uri.password == NULL) {
          p = r->the_request;
      }
      else {
          /* Don't reveal the password in the server-status view */
          p = apr_pstrcat(r->pool, r->method, " ",
                          apr_uri_unparse(r->pool, &r->parsed_uri,
                          APR_URI_UNP_OMITPASSWORD),
                          r->assbackwards ? NULL : " ", r->protocol, NULL);
      }
  
      /* now figure out if we copy over the 1st rbuflen chars or the last */
      if (!ap_mod_status_reqtail) {
          apr_cpystrn(rbuf, p, rbuflen);
      }
      else {
          apr_size_t slen = strlen(p);
          if (slen < rbuflen) {
              /* it all fits anyway */
              apr_cpystrn(rbuf, p, rbuflen);
          }
          else {
              apr_cpystrn(rbuf, p+(slen-rbuflen+1), rbuflen);
          }
      }
  }
  
  AP_DECLARE(int) ap_update_child_status_from_indexes(int child_num,
                                                      int thread_num,
                                                      int status,
                                                      request_rec *r)
  {
      int old_status;
      worker_score *ws;
      process_score *ps;
  
      if (child_num < 0) {
          return -1;
      }
  
      ws = &ap_scoreboard_image->servers[child_num][thread_num];
      old_status = ws->status;
      ws->status = status;
  
      ps = &ap_scoreboard_image->parent[child_num];
  
      if (status == SERVER_READY
          && old_status == SERVER_STARTING) {
          ws->thread_num = child_num * thread_limit + thread_num;
          ps->generation = ap_my_generation;
      }
  
      if (ap_extended_status) {
          ws->last_used = apr_time_now();
          if (status == SERVER_READY || status == SERVER_DEAD) {
              /*
               * Reset individual counters
               */
              if (status == SERVER_DEAD) {
                  ws->my_access_count = 0L;
                  ws->my_bytes_served = 0L;
              }
              ws->conn_count = 0;
              ws->conn_bytes = 0;
          }
          if (r) {
              conn_rec *c = r->connection;
              apr_cpystrn(ws->client, ap_get_remote_host(c, r->per_dir_config,
                          REMOTE_NOLOOKUP, NULL), sizeof(ws->client));
              copy_request(ws->request, sizeof(ws->request), r);
              apr_cpystrn(ws->vhost, r->server->server_hostname,
                          sizeof(ws->vhost));
          }
      }
  
      return old_status;
  }
  
  AP_DECLARE(int) ap_update_child_status(ap_sb_handle_t *sbh, int status,
                                        request_rec *r)
  {
      if (!sbh)
          return -1;
  
      return ap_update_child_status_from_indexes(sbh->child_num, sbh->thread_num,
                                                 status, r);
  }
  
  void ap_time_process_request(ap_sb_handle_t *sbh, int status)
  {
      worker_score *ws;
  
      if (!sbh)
          return;
  
      if (sbh->child_num < 0) {
          return;
      }
  
      ws = &ap_scoreboard_image->servers[sbh->child_num][sbh->thread_num];
  
      if (status == START_PREQUEST) {
          ws->start_time = apr_time_now();
      }
      else if (status == STOP_PREQUEST) {
          ws->stop_time = apr_time_now();
      }
  }
  
  AP_DECLARE(worker_score *) ap_get_scoreboard_worker(int x, int y)
  {
      if (((x < 0) || (server_limit < x)) ||
          ((y < 0) || (thread_limit < y))) {
          return(NULL); /* Out of range */
      }
      return &ap_scoreboard_image->servers[x][y];
  }
  
  AP_DECLARE(process_score *) ap_get_scoreboard_process(int x)
  {
      if ((x < 0) || (server_limit < x)) {
          return(NULL); /* Out of range */
      }
      return &ap_scoreboard_image->parent[x];
  }
  
  AP_DECLARE(global_score *) ap_get_scoreboard_global()
  {
      return ap_scoreboard_image->global;
  }
  
  AP_DECLARE(lb_score *) ap_get_scoreboard_lb(int lb_num)
  {
      if (((lb_num < 0) || (lb_limit < lb_num))) {
          return(NULL); /* Out of range */
      }
      return &ap_scoreboard_image->balancers[lb_num];
  }
  