redirect()

[disorder] / server / actions.c

/*
 * This file is part of DisOrder.
 * 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
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include <config.h>
#include "types.h"

#include "actions.h"
#include "lookups.h"

/** @brief Login cookie */
char *login_cookie;

/** @brief Return a Cookie: header */
static char *cookie(void) {
  struct dynstr d[1];
  struct url u;
  char *s;

  memset(&u, 0, sizeof u);
  dynstr_init(d);
  parse_url(config->url, &u);
  if(login_cookie) {
    dynstr_append_string(d, "disorder=");
    dynstr_append_string(d, login_cookie);
  } else {
    /* Force browser to discard cookie */
    dynstr_append_string(d, "disorder=none;Max-Age=0");
  }
  if(u.path) {
    /* The default domain matches the request host, so we need not override
     * that.  But the default path only goes up to the rightmost /, which would
     * cause the browser to expose the cookie to other CGI programs on the same
     * web server. */
    dynstr_append_string(d, ";Version=1;Path=");
    /* Formally we are supposed to quote the path, since it invariably has a
     * slash in it.  However Safari does not parse quoted paths correctly, so
     * this won't work.  Fortunately nothing else seems to care about proper
     * quoting of paths, so in practice we get with it.  (See also
     * parse_cookie() where we are liberal about cookie paths on the way back
     * in.) */
    dynstr_append_string(d, u.path);
  }
  dynstr_terminate(d);
  byte_xasprintf(&s, "Set-Cookie: %s", d->vec);
  return s;
}

/** @brief Redirect to some other action or URL */
static void redirect(const char *url) {
  /* By default use the 'back' argument */
  if(!url)
    url = cgi_get("back")
  if(url) {
    if(!strncmp(url, "http", 4))
      /* If the target is not a full URL assume it's the action */
      url = cgi_makeurl(config->url, "action", url, (char *)0);
  } else {
    /* If back= is not set just go back to the front page */
    url = config->url;
  }
  if(printf("Location: %s\n"
            "%s\n"
            "\n", url, cookie()) < 0)
    fatal(errno, "error writing to stdout");
}

/* 'playing' and 'manage' just add a Refresh: header */
static void act_playing(void) {
  long refresh = config->refresh;
  long length;
  time_t now, fin;
  char *url;

  lookups(DC_PLAYING|DC_QUEUE|DC_ENABLED|DC_RANDOM_ENABLED);
  if(playing
     && playing->state == playing_started /* i.e. not paused */
     && !disorder_length(client, playing->track, &length)
     && length
     && playing->sofar >= 0) {
    /* Try to put the next refresh at the start of the next track. */
    time(&now);
    fin = now + length - playing->sofar + config->gap;
    if(now + refresh > fin)
      refresh = fin - now;
  }
  if(queue && queue->state == playing_isscratch) {
    /* next track is a scratch, don't leave more than the inter-track gap */
    if(refresh > config->gap)
      refresh = config->gap;
  }
  if(!playing
     && ((queue
          && queue->state != playing_random)
         || random_enabled)
     && enabled) {
    /* no track playing but playing is enabled and there is something coming
     * up, must be in a gap */
    if(refresh > config->gap)
      refresh = config->gap;
  }
  if((action = cgi_get("action")))
    url = cgi_makeurl(config->url, "action", action, (char *)0);
  else
    url = config->url;
  if(printf("Content-Type: text/html\n"
            "Refresh: %ld;url=%s\n"
            "%s\n"
            "\n",
            refresh, url, cookie()) < 0)
    fatal(errno, "error writing to stdout");
  disorder_cgi_expand(action ? action : "playing");
}

/** @brief Table of actions */
static const struct action {
  /** @brief Action name */
  const char *name;
  /** @brief Action handler */
  void (*handler)(void);
} actions[] = {
  { "confirm", act_confirm },
  { "disable", act_disable },
  { "edituser", act_edituser },
  { "enable", act_enable },
  { "login", act_login },
  { "logout", act_logout },
  { "manage", act_playing },
  { "move", act_move },
  { "pause", act_pause },
  { "play", act_play },
  { "playing", act_playing },
  { "prefs", act_prefs },
  { "random-disable", act_random_disable },
  { "random-enable", act_random_enable },
  { "register", act_register },
  { "reminder", act_reminder },
  { "remove", act_remove },
  { "resume", act_resume },
  { "scratch", act_scratch },
  { "volume", act_volume },
};

/** @brief Expand a template
 * @param name Base name of template, or NULL to consult CGI args
 */
void disorder_cgi_expand(const char *name) {
  const char *p;
  
  /* For unknown actions check that they aren't evil */
  for(p = name; *p && isalnum((unsigned char)*p); ++p)
    ;
  if(*p)
    fatal(0, "invalid action name '%s'", action);
  byte_xasprintf((char **)&p, "%s.tmpl", action);
  if(mx_expand_file(p, sink_stdio(stdout), 0) == -1
     || fflush(stdout) < 0)
    fatal(errno, "error writing to stdout");
}

/** @brief Execute a web action
 * @param action Action to perform, or NULL to consult CGI args
 *
 * If no recognized action is specified then 'playing' is assumed.
 */
void disorder_cgi_action(const char *action) {
  int n;
  char *s;

  /* Consult CGI args if caller had no view */
  if(!action)
    action = cgi_get("action");
  /* Pick a default if nobody cares at all */
  if(!action) {
    /* We allow URLs which are just c=... in order to keep confirmation URLs,
     * which are user-facing, as short as possible.  Actually we could lose the
     * c= for this... */
    if(cgi_get("c"))
      action = "confirm";
    else
      action = "playing";
    /* Make sure 'action' is always set */
    cgi_set("action", action);
  }
  if((n = TABLE_FIND(actions, struct action, name, action)) >= 0)
    /* Its a known action */
    actions[n].handler();
  else {
    /* Just expand the template */
    if(printf("Content-Type: text/html\n"
              "%s\n"
              "\n", cookie()) < 0)
      fatal(errno, "error writing to stdout");
    disorder_cgi_expand(action);
  }
}

/** @brief Generate an error page */
void disorder_cgi_error(const char *msg, ...) {
  va_list ap;

  va_start(ap, msg);
  byte_xvasprintf(&error_string, msg, ap);
  va_end(ap);
  disorder_cgi_expand("error");
}

/** @brief Log in as the current user or guest if none */
void disorder_cgi_login(dcgi_state *ds, struct sink *output) {
  /* Junk old data */
  disorder_macros_reset();
  /* Reconnect */
  if(disorder_connect_cookie(client, login_cookie)) {
    disorder_cgi_error("Cannot connect to server");
    exit(0);
  }
  /* If there was a cookie but it went bad, we forget it */
  if(login_cookie && !strcmp(disorder_user(>client), "guest"))
    login_cookie = 0;
}

/*
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*/