/* ====================================================================
 * Copyright (c) 1995 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
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 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
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 *    endorse or promote products derived from this software without
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 * 5. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
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 *
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
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 * project, please see <http://www.apache.org/>.
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 */

/*
 * mod_limit.c: limits on daily usage by users
 * A user can only xfer so many bytes/period.
 *
 * Sameer Parekh
 */


#include "httpd.h"
#include "http_config.h"
#include "mod_limit.h"
#include <sys/mman.h>

module limit_module;

typedef struct {
    struct user_limit *tableptr;
    char *dataFile;
} limit_state;

void *
make_limit_state (pool *p, server_rec *s)
{
    limit_state *cls =
      (limit_state *)palloc (p, sizeof (limit_state));

    cls->tableptr == NULL;
    cls->dataFile == NULL;

    return (void *)cls;
}

char *
set_limit (cmd_parms *parms, void *dummy, char *arg)
{
    limit_state *cls = get_module_config (parms->server->module_config,
					       &limit_module);
    /* Create mmaped data */
    cls->dataFile = arg;

    return NULL;
}

command_rec limit_cmds[] = {
{ "LimitServer", set_limit, NULL, RSRC_CONF, TAKE1,
    "the filename of the limitation database" },
{ NULL }
};

void
init_limit (server_rec *s, pool *p)
{
  limit_state *cls = get_module_config (s->module_config,
					&limit_module);
  FILE *fp;
  int uid, max;
  char name[MAX_STRING_LEN];

  cls->tableptr = 
    (struct user_limit *) mmap((caddr_t)0, NUM_RECORDS *
			       sizeof(struct user_limit), PROT_READ | PROT_WRITE,
			       MAP_ANON | MAP_SHARED, -1, 0);
  if(cls->tableptr == (struct user_limit *) -1 )
    {
      perror("mmap");
      fprintf(stderr, "httpd: Could not map memory for limits\n");
      exit(1);
    }

  /* Open up the initialization file */
  cls->dataFile = server_root_relative(p, cls->dataFile);
  fp=fopen(cls->dataFile, "r");
  while(fscanf(fp, "%d %s %d", &uid, name, &max) != EOF)
    {
      if(uid > NUM_RECORDS)
	continue;
      strncpy(cls->tableptr[uid].account, name, 16);
      cls->tableptr[uid].bytes_sent = 0;
      cls->tableptr[uid].bytes_max = max;
    }
  fclose(fp);
}

int
check_limits(request_rec *r)
{
  limit_state *cls = get_module_config(r->server->module_config,
				       &limit_module);

  if(r->finfo.st_uid > NUM_RECORDS)
    return OK;

  if(cls->tableptr[r->finfo.st_uid].bytes_max == 0)
    return OK;

  if(cls->tableptr[r->finfo.st_uid].bytes_max
     < cls->tableptr[r->finfo.st_uid].bytes_sent)
    {
      log_reason("user over limit", r->filename, r);
      return SERVICE_UNAVAILABLE;
    }

  return OK;
}

int
limit_transaction(request_rec *orig)
{
  /* Add some bits to a given user's data */

  limit_state *cls = get_module_config (orig->server->module_config,
					     &limit_module);

  /* Find the actual request */
  for( ; orig->next != NULL; orig = orig->next);

  if(orig->finfo.st_mode == 0)
    {
      return OK;
    }
  if(orig->finfo.st_uid > NUM_RECORDS)
    return OK;
  if(orig->bytes_sent > 0)
    cls->tableptr[orig->finfo.st_uid].bytes_sent += orig->bytes_sent;

  return OK;
}

static int
limit_trans(request_rec *r)
{
  limit_state *cls = get_module_config(r->server->module_config,
				       &limit_module);

  if(!strncmp("/limits/", r->uri, 8))
    {
      r->filename = pstrcat(r->pool, "limits:", r->uri+8, NULL);
      return OK;
    }
  return DECLINED;
}

static int
limit_type(request_rec *r)
{
  if(!strncmp(r->filename, "limits:", 7))
    {
      r->content_type = LIMIT_MAGIC_TYPE;
      return OK;
    }
  return DECLINED;
}

static int
limit_handler(request_rec *r)
{
  limit_state *cls = get_module_config(r->server->module_config,
				       &limit_module);
  int index;

  /* Spew to client info about limits */

  /* This version ignores the file, later versions */
  /* will use the file to make info more specific */
  r->content_type = "text/html";
  send_http_header(r);

  rprintf(r, "<TABLE BORDER>\n"
	     "<TR><TH>Name</TH><TH>UID</TH><TH>Used</TH><TH>Max</TH></TR>\n");
  for(index = 0; index < NUM_RECORDS; index++)
    {
      if(cls->tableptr[index].bytes_sent != 0)
	rprintf(r, "<TR><TD>%s</TD><TD>%d</TD><TD>%6.2f</TD><TD>%6.2f</TD>\n",
		cls->tableptr[index].account,
		index,
		(float) cls->tableptr[index].bytes_sent / (float) 1048576,
		(float) cls->tableptr[index].bytes_max / (float) 1048576);
    }
  rprintf(r, "</TABLE>\n");
  return OK;
}
	
handler_rec limit_handlers[] = {
  { LIMIT_MAGIC_TYPE, limit_handler },
  { NULL }
};
 
module limit_module = {
   STANDARD_MODULE_STUFF,
   init_limit,    		/* initializer */
   NULL,			/* create per-dir config */
   NULL,			/* merge per-dir config */
   make_limit_state,   	        /* server config */
   NULL,			/* merge server config */
   limit_cmds, 		        /* command table */
   limit_handlers,		/* handlers */
   limit_trans,			/* filename translation */
   NULL,			/* check_user_id */
   NULL,			/* check auth */
   check_limits,		/* check access */
   limit_type,			/* type_checker */
   NULL,			/* fixups */
   limit_transaction   	/* logger */
};