cookie.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

/***


RECEIVING COOKIE INFORMATION
============================

struct CookieInfo *cookie_init(char *file);

        Inits a cookie struct to store data in a local file. This is always
        called before any cookies are set.

int cookies_set(struct CookieInfo *cookie, char *cookie_line);

        The 'cookie_line' parameter is a full "Set-cookie:" line as
        received from a server.

        The function need to replace previously stored lines that this new
        line superceeds.

        It may remove lines that are expired.

        It should return an indication of success/error.


SENDING COOKIE INFORMATION
==========================

struct Cookies *cookie_getlist(struct CookieInfo *cookie,
                               char *host, char *path, bool secure);

        For a given host and path, return a linked list of cookies that
        the client should send to the server if used now. The secure
        boolean informs the cookie if a secure connection is achieved or
        not.

        It shall only return cookies that haven't expired.


Example set of cookies:

    Set-cookie: PRODUCTINFO=webxpress; domain=.fidelity.com; path=/; secure
    Set-cookie: PERSONALIZE=none;expires=Monday, 13-Jun-1988 03:04:55 GMT;
    domain=.fidelity.com; path=/ftgw; secure
    Set-cookie: FidHist=none;expires=Monday, 13-Jun-1988 03:04:55 GMT;
    domain=.fidelity.com; path=/; secure
    Set-cookie: FidOrder=none;expires=Monday, 13-Jun-1988 03:04:55 GMT;
    domain=.fidelity.com; path=/; secure
    Set-cookie: DisPend=none;expires=Monday, 13-Jun-1988 03:04:55 GMT;
    domain=.fidelity.com; path=/; secure
    Set-cookie: FidDis=none;expires=Monday, 13-Jun-1988 03:04:55 GMT;
    domain=.fidelity.com; path=/; secure
    Set-cookie:
    Session_Key@6791a9e0-901a-11d0-a1c8-9b012c88aa77=none;expires=Monday,
    13-Jun-1988 03:04:55 GMT; domain=.fidelity.com; path=/; secure
****/


#include "curl_setup.h"

#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)

#define _MPRINTF_REPLACE
#include <curl/mprintf.h>

#include "urldata.h"
#include "cookie.h"
#include "strequal.h"
#include "strtok.h"
#include "sendf.h"
#include "curl_memory.h"
#include "share.h"
#include "strtoofft.h"
#include "rawstr.h"
#include "curl_memrchr.h"

/* The last #include file should be: */
#include "memdebug.h"

static void freecookie(struct Cookie *co)
{
  if(co->expirestr)
    free(co->expirestr);
  if(co->domain)
    free(co->domain);
  if(co->path)
    free(co->path);
  if(co->name)
    free(co->name);
  if(co->value)
    free(co->value);
  if(co->maxage)
    free(co->maxage);
  if(co->version)
    free(co->version);

  free(co);
}

static bool tailmatch(const char *cooke_domain, const char *hostname)
{
  size_t cookie_domain_len = strlen(cooke_domain);
  size_t hostname_len = strlen(hostname);

  if(hostname_len < cookie_domain_len)
    return FALSE;

  if(!Curl_raw_equal(cooke_domain, hostname+hostname_len-cookie_domain_len))
    return FALSE;

  /* A lead char of cookie_domain is not '.'.
     RFC6265 4.1.2.3. The Domain Attribute says:
       For example, if the value of the Domain attribute is
       "example.com", the user agent will include the cookie in the Cookie
       header when making HTTP requests to example.com, www.example.com, and
       www.corp.example.com.
   */
  if(hostname_len == cookie_domain_len)
    return TRUE;
  if('.' == *(hostname + hostname_len - cookie_domain_len - 1))
    return TRUE;
  return FALSE;
}

static bool pathmatch(const char* cookie_path, const char* url_path)
{
  size_t cookie_path_len = strlen(cookie_path);
  size_t url_path_len = strlen(url_path);

  if(url_path_len < cookie_path_len)
    return FALSE;

  /* not using checkprefix() because matching should be case-sensitive */
  if(strncmp(cookie_path, url_path, cookie_path_len))
    return FALSE;

  /* it is true if cookie_path and url_path are the same */
  if(cookie_path_len == url_path_len)
    return TRUE;

  /* here, cookie_path_len < url_path_len */

  /* it is false if cookie path is /example and url path is /examples */
  if(cookie_path[cookie_path_len - 1] != '/') {
    if(url_path[cookie_path_len] != '/') {
      return FALSE;
    }
  }
  /* matching! */
  return TRUE;
}

/*
 * Load cookies from all given cookie files (CURLOPT_COOKIEFILE).
 */
void Curl_cookie_loadfiles(struct SessionHandle *data)
{
  struct curl_slist *list = data->change.cookielist;
  if(list) {
    Curl_share_lock(data, CURL_LOCK_DATA_COOKIE, CURL_LOCK_ACCESS_SINGLE);
    while(list) {
      data->cookies = Curl_cookie_init(data,
                                       list->data,
                                       data->cookies,
                                       data->set.cookiesession);
      list = list->next;
    }
    curl_slist_free_all(data->change.cookielist); /* clean up list */
    data->change.cookielist = NULL; /* don't do this again! */
    Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
  }
}

/*
 * strstore() makes a strdup() on the 'newstr' and if '*str' is non-NULL
 * that will be freed before the allocated string is stored there.
 *
 * It is meant to easily replace strdup()
 */
static void strstore(char **str, const char *newstr)
{
  if(*str)
    free(*str);
  *str = strdup(newstr);
}


/****************************************************************************
 *
 * Curl_cookie_add()
 *
 * Add a single cookie line to the cookie keeping object.
 *
 * Be aware that sometimes we get an IP-only host name, and that might also be
 * a numerical IPv6 address.
 *
 ***************************************************************************/

struct Cookie *
Curl_cookie_add(struct SessionHandle *data,
                /* The 'data' pointer here may be NULL at times, and thus
                   must only be used very carefully for things that can deal
                   with data being NULL. Such as infof() and similar */

                struct CookieInfo *c,
                bool httpheader, /* TRUE if HTTP header-style line */
                char *lineptr,   /* first character of the line */
                const char *domain, /* default domain */
                const char *path)   /* full path used when this cookie is set,
                                       used to get default path for the cookie
                                       unless set */
{
  struct Cookie *clist;
  char name[MAX_NAME];
  struct Cookie *co;
  struct Cookie *lastc=NULL;
  time_t now = time(NULL);
  bool replace_old = FALSE;
  bool badcookie = FALSE; /* cookies are good by default. mmmmm yummy */

#ifdef CURL_DISABLE_VERBOSE_STRINGS
  (void)data;
#endif

  /* First, alloc and init a new struct for it */
  co = calloc(1, sizeof(struct Cookie));
  if(!co)
    return NULL; /* bail out if we're this low on memory */

  if(httpheader) {
    /* This line was read off a HTTP-header */
    const char *ptr;
    const char *semiptr;
    char *what;

    what = malloc(MAX_COOKIE_LINE);
    if(!what) {
      free(co);
      return NULL;
    }

    semiptr=strchr(lineptr, ';'); /* first, find a semicolon */

    while(*lineptr && ISBLANK(*lineptr))
      lineptr++;

    ptr = lineptr;
    do {
      /* we have a <what>=<this> pair or a stand-alone word here */
      name[0]=what[0]=0; /* init the buffers */
      if(1 <= sscanf(ptr, "%" MAX_NAME_TXT "[^;\r\n =]=%"
                     MAX_COOKIE_LINE_TXT "[^;\r\n]",
                     name, what)) {
        /* Use strstore() below to properly deal with received cookie
           headers that have the same string property set more than once,
           and then we use the last one. */
        const char *whatptr;
        bool done = FALSE;
        bool sep;
        size_t len=strlen(what);
        const char *endofn = &ptr[ strlen(name) ];

        /* skip trailing spaces in name */
        while(*endofn && ISBLANK(*endofn))
          endofn++;

        /* name ends with a '=' ? */
        sep = (*endofn == '=')?TRUE:FALSE;

        /* Strip off trailing whitespace from the 'what' */
        while(len && ISBLANK(what[len-1])) {
          what[len-1]=0;
          len--;
        }

        /* Skip leading whitespace from the 'what' */
        whatptr=what;
        while(*whatptr && ISBLANK(*whatptr))
          whatptr++;

        if(!len) {
          /* this was a "<name>=" with no content, and we must allow
             'secure' and 'httponly' specified this weirdly */
          done = TRUE;
          if(Curl_raw_equal("secure", name))
            co->secure = TRUE;
          else if(Curl_raw_equal("httponly", name))
            co->httponly = TRUE;
          else if(sep)
            /* there was a '=' so we're not done parsing this field */
            done = FALSE;
        }
        if(done)
          ;
        else if(Curl_raw_equal("path", name)) {
          strstore(&co->path, whatptr);
          if(!co->path) {
            badcookie = TRUE; /* out of memory bad */
            break;
          }
        }
        else if(Curl_raw_equal("domain", name)) {
          /* Now, we make sure that our host is within the given domain,
             or the given domain is not valid and thus cannot be set. */

          if('.' == whatptr[0])
            whatptr++; /* ignore preceding dot */

          if(!domain || tailmatch(whatptr, domain)) {
            const char *tailptr=whatptr;
            if(tailptr[0] == '.')
              tailptr++;
            strstore(&co->domain, tailptr); /* don't prefix w/dots
                                               internally */
            if(!co->domain) {
              badcookie = TRUE;
              break;
            }
            co->tailmatch=TRUE; /* we always do that if the domain name was
                                   given */
          }
          else {
            /* we did not get a tailmatch and then the attempted set domain
               is not a domain to which the current host belongs. Mark as
               bad. */
            badcookie=TRUE;
            infof(data, "skipped cookie with bad tailmatch domain: %s\n",
                  whatptr);
          }
        }
        else if(Curl_raw_equal("version", name)) {
          strstore(&co->version, whatptr);
          if(!co->version) {
            badcookie = TRUE;
            break;
          }
        }
        else if(Curl_raw_equal("max-age", name)) {
          /* Defined in RFC2109:

             Optional.  The Max-Age attribute defines the lifetime of the
             cookie, in seconds.  The delta-seconds value is a decimal non-
             negative integer.  After delta-seconds seconds elapse, the
             client should discard the cookie.  A value of zero means the
             cookie should be discarded immediately.

          */
          strstore(&co->maxage, whatptr);
          if(!co->maxage) {
            badcookie = TRUE;
            break;
          }
          co->expires =
            strtol((*co->maxage=='\"')?&co->maxage[1]:&co->maxage[0],NULL,10)
            + (long)now;
        }
        else if(Curl_raw_equal("expires", name)) {
          strstore(&co->expirestr, whatptr);
          if(!co->expirestr) {
            badcookie = TRUE;
            break;
          }
          /* Note that if the date couldn't get parsed for whatever reason,
             the cookie will be treated as a session cookie */
          co->expires = curl_getdate(what, &now);

          /* Session cookies have expires set to 0 so if we get that back
             from the date parser let's add a second to make it a
             non-session cookie */
          if(co->expires == 0)
            co->expires = 1;
          else if(co->expires < 0)
            co->expires = 0;
        }
        else if(!co->name) {
          co->name = strdup(name);
          co->value = strdup(whatptr);
          if(!co->name || !co->value) {
            badcookie = TRUE;
            break;
          }
        }
        /*
          else this is the second (or more) name we don't know
          about! */
      }
      else {
        /* this is an "illegal" <what>=<this> pair */
      }

      if(!semiptr || !*semiptr) {
        /* we already know there are no more cookies */
        semiptr = NULL;
        continue;
      }

      ptr=semiptr+1;
      while(*ptr && ISBLANK(*ptr))
        ptr++;
      semiptr=strchr(ptr, ';'); /* now, find the next semicolon */

      if(!semiptr && *ptr)
        /* There are no more semicolons, but there's a final name=value pair
           coming up */
        semiptr=strchr(ptr, '\0');
    } while(semiptr);

    if(!badcookie && !co->domain) {
      if(domain) {
        /* no domain was given in the header line, set the default */
        co->domain=strdup(domain);
        if(!co->domain)
          badcookie = TRUE;
      }
    }

    if(!badcookie && !co->path && path) {
      /* No path was given in the header line, set the default.
         Note that the passed-in path to this function MAY have a '?' and
         following part that MUST not be stored as part of the path. */
      char *queryp = strchr(path, '?');

      /* queryp is where the interesting part of the path ends, so now we
         want to the find the last */
      char *endslash;
      if(!queryp)
        endslash = strrchr(path, '/');
      else
        endslash = memrchr(path, '/', (size_t)(queryp - path));
      if(endslash) {
        size_t pathlen = (size_t)(endslash-path+1); /* include ending slash */
        co->path=malloc(pathlen+1); /* one extra for the zero byte */
        if(co->path) {
          memcpy(co->path, path, pathlen);
          co->path[pathlen]=0; /* zero terminate */
        }
        else
          badcookie = TRUE;
      }
    }

    free(what);

    if(badcookie || !co->name) {
      /* we didn't get a cookie name or a bad one,
         this is an illegal line, bail out */
      freecookie(co);
      return NULL;
    }

  }
  else {
    /* This line is NOT a HTTP header style line, we do offer support for
       reading the odd netscape cookies-file format here */
    char *ptr;
    char *firstptr;
    char *tok_buf=NULL;
    int fields;

    /* IE introduced HTTP-only cookies to prevent XSS attacks. Cookies
       marked with httpOnly after the domain name are not accessible
       from javascripts, but since curl does not operate at javascript
       level, we include them anyway. In Firefox's cookie files, these
       lines are preceded with #HttpOnly_ and then everything is
       as usual, so we skip 10 characters of the line..
    */
    if(strncmp(lineptr, "#HttpOnly_", 10) == 0) {
      lineptr += 10;
      co->httponly = TRUE;
    }

    if(lineptr[0]=='#') {
      /* don't even try the comments */
      free(co);
      return NULL;
    }
    /* strip off the possible end-of-line characters */
    ptr=strchr(lineptr, '\r');
    if(ptr)
      *ptr=0; /* clear it */
    ptr=strchr(lineptr, '\n');
    if(ptr)
      *ptr=0; /* clear it */

    firstptr=strtok_r(lineptr, "\t", &tok_buf); /* tokenize it on the TAB */

    /* Now loop through the fields and init the struct we already have
       allocated */
    for(ptr=firstptr, fields=0; ptr && !badcookie;
        ptr=strtok_r(NULL, "\t", &tok_buf), fields++) {
      switch(fields) {
      case 0:
        if(ptr[0]=='.') /* skip preceding dots */
          ptr++;
        co->domain = strdup(ptr);
        if(!co->domain)
          badcookie = TRUE;
        break;
      case 1:
        /* This field got its explanation on the 23rd of May 2001 by
           Andrés García:

           flag: A TRUE/FALSE value indicating if all machines within a given
           domain can access the variable. This value is set automatically by
           the browser, depending on the value you set for the domain.

           As far as I can see, it is set to true when the cookie says
           .domain.com and to false when the domain is complete www.domain.com
        */
        co->tailmatch = Curl_raw_equal(ptr, "TRUE")?TRUE:FALSE;
        break;
      case 2:
        /* It turns out, that sometimes the file format allows the path
           field to remain not filled in, we try to detect this and work
           around it! Andrés García made us aware of this... */
        if(strcmp("TRUE", ptr) && strcmp("FALSE", ptr)) {
          /* only if the path doesn't look like a boolean option! */
          co->path = strdup(ptr);
          if(!co->path)
            badcookie = TRUE;
          break;
        }
        /* this doesn't look like a path, make one up! */
        co->path = strdup("/");
        if(!co->path)
          badcookie = TRUE;
        fields++; /* add a field and fall down to secure */
        /* FALLTHROUGH */
      case 3:
        co->secure = Curl_raw_equal(ptr, "TRUE")?TRUE:FALSE;
        break;
      case 4:
        co->expires = curlx_strtoofft(ptr, NULL, 10);
        break;
      case 5:
        co->name = strdup(ptr);
        if(!co->name)
          badcookie = TRUE;
        break;
      case 6:
        co->value = strdup(ptr);
        if(!co->value)
          badcookie = TRUE;
        break;
      }
    }
    if(6 == fields) {
      /* we got a cookie with blank contents, fix it */
      co->value = strdup("");
      if(!co->value)
        badcookie = TRUE;
      else
        fields++;
    }

    if(!badcookie && (7 != fields))
      /* we did not find the sufficient number of fields */
      badcookie = TRUE;

    if(badcookie) {
      freecookie(co);
      return NULL;
    }

  }

  if(!c->running &&    /* read from a file */
     c->newsession &&  /* clean session cookies */
     !co->expires) {   /* this is a session cookie since it doesn't expire! */
    freecookie(co);
    return NULL;
  }

  co->livecookie = c->running;

  /* now, we have parsed the incoming line, we must now check if this
     superceeds an already existing cookie, which it may if the previous have
     the same domain and path as this */

  clist = c->cookies;
  replace_old = FALSE;
  while(clist) {
    if(Curl_raw_equal(clist->name, co->name)) {
      /* the names are identical */

      if(clist->domain && co->domain) {
        if(Curl_raw_equal(clist->domain, co->domain))
          /* The domains are identical */
          replace_old=TRUE;
      }
      else if(!clist->domain && !co->domain)
        replace_old = TRUE;

      if(replace_old) {
        /* the domains were identical */

        if(clist->path && co->path) {
          if(Curl_raw_equal(clist->path, co->path)) {
            replace_old = TRUE;
          }
          else
            replace_old = FALSE;
        }
        else if(!clist->path && !co->path)
          replace_old = TRUE;
        else
          replace_old = FALSE;

      }

      if(replace_old && !co->livecookie && clist->livecookie) {
        /* Both cookies matched fine, except that the already present
           cookie is "live", which means it was set from a header, while
           the new one isn't "live" and thus only read from a file. We let
           live cookies stay alive */

        /* Free the newcomer and get out of here! */
        freecookie(co);
        return NULL;
      }

      if(replace_old) {
        co->next = clist->next; /* get the next-pointer first */

        /* then free all the old pointers */
        free(clist->name);
        if(clist->value)
          free(clist->value);
        if(clist->domain)
          free(clist->domain);
        if(clist->path)
          free(clist->path);
        if(clist->expirestr)
          free(clist->expirestr);

        if(clist->version)
          free(clist->version);
        if(clist->maxage)
          free(clist->maxage);

        *clist = *co;  /* then store all the new data */

        free(co);   /* free the newly alloced memory */
        co = clist; /* point to the previous struct instead */

        /* We have replaced a cookie, now skip the rest of the list but
           make sure the 'lastc' pointer is properly set */
        do {
          lastc = clist;
          clist = clist->next;
        } while(clist);
        break;
      }
    }
    lastc = clist;
    clist = clist->next;
  }

  if(c->running)
    /* Only show this when NOT reading the cookies from a file */
    infof(data, "%s cookie %s=\"%s\" for domain %s, path %s, "
          "expire %" FORMAT_OFF_T "\n",
          replace_old?"Replaced":"Added", co->name, co->value,
          co->domain, co->path, co->expires);

  if(!replace_old) {
    /* then make the last item point on this new one */
    if(lastc)
      lastc->next = co;
    else
      c->cookies = co;
    c->numcookies++; /* one more cookie in the jar */
  }

  return co;
}

/*****************************************************************************
 *
 * Curl_cookie_init()
 *
 * Inits a cookie struct to read data from a local file. This is always
 * called before any cookies are set. File may be NULL.
 *
 * If 'newsession' is TRUE, discard all "session cookies" on read from file.
 *
 ****************************************************************************/
struct CookieInfo *Curl_cookie_init(struct SessionHandle *data,
                                    const char *file,
                                    struct CookieInfo *inc,
                                    bool newsession)
{
  struct CookieInfo *c;
  FILE *fp;
  bool fromfile=TRUE;

  if(NULL == inc) {
    /* we didn't get a struct, create one */
    c = calloc(1, sizeof(struct CookieInfo));
    if(!c)
      return NULL; /* failed to get memory */
    c->filename = strdup(file?file:"none"); /* copy the name just in case */
  }
  else {
    /* we got an already existing one, use that */
    c = inc;
  }
  c->running = FALSE; /* this is not running, this is init */

  if(file && strequal(file, "-")) {
    fp = stdin;
    fromfile=FALSE;
  }
  else if(file && !*file) {
    /* points to a "" string */
    fp = NULL;
  }
  else
    fp = file?fopen(file, "r"):NULL;

  c->newsession = newsession; /* new session? */

  if(fp) {
    char *lineptr;
    bool headerline;

    char *line = malloc(MAX_COOKIE_LINE);
    if(line) {
      while(fgets(line, MAX_COOKIE_LINE, fp)) {
        if(checkprefix("Set-Cookie:", line)) {
          /* This is a cookie line, get it! */
          lineptr=&line[11];
          headerline=TRUE;
        }
        else {
          lineptr=line;
          headerline=FALSE;
        }
        while(*lineptr && ISBLANK(*lineptr))
          lineptr++;

        Curl_cookie_add(data, c, headerline, lineptr, NULL, NULL);
      }
      free(line); /* free the line buffer */
    }
    if(fromfile)
      fclose(fp);
  }

  c->running = TRUE;          /* now, we're running */

  return c;
}

/* sort this so that the longest path gets before the shorter path */
static int cookie_sort(const void *p1, const void *p2)
{
  struct Cookie *c1 = *(struct Cookie **)p1;
  struct Cookie *c2 = *(struct Cookie **)p2;
  size_t l1, l2;

  /* 1 - compare cookie path lengths */
  l1 = c1->path ? strlen(c1->path) : 0;
  l2 = c2->path ? strlen(c2->path) : 0;

  if(l1 != l2)
    return (l2 > l1) ? 1 : -1 ; /* avoid size_t <=> int conversions */

  /* 2 - compare cookie domain lengths */
  l1 = c1->domain ? strlen(c1->domain) : 0;
  l2 = c2->domain ? strlen(c2->domain) : 0;

  if(l1 != l2)
    return (l2 > l1) ? 1 : -1 ;  /* avoid size_t <=> int conversions */

  /* 3 - compare cookie names */
  if(c1->name && c2->name)
    return strcmp(c1->name, c2->name);

  /* sorry, can't be more deterministic */
  return 0;
}

/*****************************************************************************
 *
 * Curl_cookie_getlist()
 *
 * For a given host and path, return a linked list of cookies that the
 * client should send to the server if used now. The secure boolean informs
 * the cookie if a secure connection is achieved or not.
 *
 * It shall only return cookies that haven't expired.
 *
 ****************************************************************************/

struct Cookie *Curl_cookie_getlist(struct CookieInfo *c,
                                   const char *host, const char *path,
                                   bool secure)
{
  struct Cookie *newco;
  struct Cookie *co;
  time_t now = time(NULL);
  struct Cookie *mainco=NULL;
  size_t matches = 0;

  if(!c || !c->cookies)
    return NULL; /* no cookie struct or no cookies in the struct */

  co = c->cookies;

  while(co) {
    /* only process this cookie if it is not expired or had no expire
       date AND that if the cookie requires we're secure we must only
       continue if we are! */
    if((!co->expires || (co->expires > now)) &&
       (co->secure?secure:TRUE)) {

      /* now check if the domain is correct */
      if(!co->domain ||
         (co->tailmatch && tailmatch(co->domain, host)) ||
         (!co->tailmatch && Curl_raw_equal(host, co->domain)) ) {
        /* the right part of the host matches the domain stuff in the
           cookie data */

        /* now check the left part of the path with the cookies path
           requirement */
        if(!co->path || pathmatch(co->path, path) ) {

          /* and now, we know this is a match and we should create an
             entry for the return-linked-list */

          newco = malloc(sizeof(struct Cookie));
          if(newco) {
            /* first, copy the whole source cookie: */
            memcpy(newco, co, sizeof(struct Cookie));

            /* then modify our next */
            newco->next = mainco;

            /* point the main to us */
            mainco = newco;

            matches++;
          }
          else {
            fail:
            /* failure, clear up the allocated chain and return NULL */
            while(mainco) {
              co = mainco->next;
              free(mainco);
              mainco = co;
            }

            return NULL;
          }
        }
      }
    }
    co = co->next;
  }

  if(matches) {
    /* Now we need to make sure that if there is a name appearing more than
       once, the longest specified path version comes first. To make this
       the swiftest way, we just sort them all based on path length. */
    struct Cookie **array;
    size_t i;

    /* alloc an array and store all cookie pointers */
    array = malloc(sizeof(struct Cookie *) * matches);
    if(!array)
      goto fail;

    co = mainco;

    for(i=0; co; co = co->next)
      array[i++] = co;

    /* now sort the cookie pointers in path length order */
    qsort(array, matches, sizeof(struct Cookie *), cookie_sort);

    /* remake the linked list order according to the new order */

    mainco = array[0]; /* start here */
    for(i=0; i<matches-1; i++)
      array[i]->next = array[i+1];
    array[matches-1]->next = NULL; /* terminate the list */

    free(array); /* remove the temporary data again */
  }

  return mainco; /* return the new list */
}

/*****************************************************************************
 *
 * Curl_cookie_clearall()
 *
 * Clear all existing cookies and reset the counter.
 *
 ****************************************************************************/
void Curl_cookie_clearall(struct CookieInfo *cookies)
{
  if(cookies) {
    Curl_cookie_freelist(cookies->cookies, TRUE);
    cookies->cookies = NULL;
    cookies->numcookies = 0;
  }
}

/*****************************************************************************
 *
 * Curl_cookie_freelist()
 *
 * Free a list of cookies previously returned by Curl_cookie_getlist();
 *
 * The 'cookiestoo' argument tells this function whether to just free the
 * list or actually also free all cookies within the list as well.
 *
 ****************************************************************************/

void Curl_cookie_freelist(struct Cookie *co, bool cookiestoo)
{
  struct Cookie *next;
  if(co) {
    while(co) {
      next = co->next;
      if(cookiestoo)
        freecookie(co);
      else
        free(co); /* we only free the struct since the "members" are all just
                     pointed out in the main cookie list! */
      co = next;
    }
  }
}


/*****************************************************************************
 *
 * Curl_cookie_clearsess()
 *
 * Free all session cookies in the cookies list.
 *
 ****************************************************************************/
void Curl_cookie_clearsess(struct CookieInfo *cookies)
{
  struct Cookie *first, *curr, *next, *prev = NULL;

  if(!cookies || !cookies->cookies)
    return;

  first = curr = prev = cookies->cookies;

  for(; curr; curr = next) {
    next = curr->next;
    if(!curr->expires) {
      if(first == curr)
        first = next;

      if(prev == curr)
        prev = next;
      else
        prev->next = next;

      freecookie(curr);
      cookies->numcookies--;
    }
    else
      prev = curr;
  }

  cookies->cookies = first;
}


/*****************************************************************************
 *
 * Curl_cookie_cleanup()
 *
 * Free a "cookie object" previous created with cookie_init().
 *
 ****************************************************************************/
void Curl_cookie_cleanup(struct CookieInfo *c)
{
  struct Cookie *co;
  struct Cookie *next;
  if(c) {
    if(c->filename)
      free(c->filename);
    co = c->cookies;

    while(co) {
      next = co->next;
      freecookie(co);
      co = next;
    }
    free(c); /* free the base struct as well */
  }
}

/* get_netscape_format()
 *
 * Formats a string for Netscape output file, w/o a newline at the end.
 *
 * Function returns a char * to a formatted line. Has to be free()d
*/
static char *get_netscape_format(const struct Cookie *co)
{
  return aprintf(
    "%s"     /* httponly preamble */
    "%s%s\t" /* domain */
    "%s\t"   /* tailmatch */
    "%s\t"   /* path */
    "%s\t"   /* secure */
    "%" FORMAT_OFF_T "\t"   /* expires */
    "%s\t"   /* name */
    "%s",    /* value */
    co->httponly?"#HttpOnly_":"",
    /* Make sure all domains are prefixed with a dot if they allow
       tailmatching. This is Mozilla-style. */
    (co->tailmatch && co->domain && co->domain[0] != '.')? ".":"",
    co->domain?co->domain:"unknown",
    co->tailmatch?"TRUE":"FALSE",
    co->path?co->path:"/",
    co->secure?"TRUE":"FALSE",
    co->expires,
    co->name,
    co->value?co->value:"");
}

/*
 * cookie_output()
 *
 * Writes all internally known cookies to the specified file. Specify
 * "-" as file name to write to stdout.
 *
 * The function returns non-zero on write failure.
 */
static int cookie_output(struct CookieInfo *c, const char *dumphere)
{
  struct Cookie *co;
  FILE *out;
  bool use_stdout=FALSE;

  if((NULL == c) || (0 == c->numcookies))
    /* If there are no known cookies, we don't write or even create any
       destination file */
    return 0;

  if(strequal("-", dumphere)) {
    /* use stdout */
    out = stdout;
    use_stdout=TRUE;
  }
  else {
    out = fopen(dumphere, "w");
    if(!out)
      return 1; /* failure */
  }

  if(c) {
    char *format_ptr;

    fputs("# Netscape HTTP Cookie File\n"
          "# http://curl.haxx.se/docs/http-cookies.html\n"
          "# This file was generated by libcurl! Edit at your own risk.\n\n",
          out);
    co = c->cookies;

    while(co) {
      format_ptr = get_netscape_format(co);
      if(format_ptr == NULL) {
        fprintf(out, "#\n# Fatal libcurl error\n");
        if(!use_stdout)
          fclose(out);
        return 1;
      }
      fprintf(out, "%s\n", format_ptr);
      free(format_ptr);
      co=co->next;
    }
  }

  if(!use_stdout)
    fclose(out);

  return 0;
}

struct curl_slist *Curl_cookie_list(struct SessionHandle *data)
{
  struct curl_slist *list = NULL;
  struct curl_slist *beg;
  struct Cookie *c;
  char *line;

  if((data->cookies == NULL) ||
      (data->cookies->numcookies == 0))
    return NULL;

  c = data->cookies->cookies;

  while(c) {
    /* fill the list with _all_ the cookies we know */
    line = get_netscape_format(c);
    if(!line) {
      curl_slist_free_all(list);
      return NULL;
    }
    beg = curl_slist_append(list, line);
    free(line);
    if(!beg) {
      curl_slist_free_all(list);
      return NULL;
    }
    list = beg;
    c = c->next;
  }

  return list;
}

void Curl_flush_cookies(struct SessionHandle *data, int cleanup)
{
  if(data->set.str[STRING_COOKIEJAR]) {
    if(data->change.cookielist) {
      /* If there is a list of cookie files to read, do it first so that
         we have all the told files read before we write the new jar.
         Curl_cookie_loadfiles() LOCKS and UNLOCKS the share itself! */
      Curl_cookie_loadfiles(data);
    }

    Curl_share_lock(data, CURL_LOCK_DATA_COOKIE, CURL_LOCK_ACCESS_SINGLE);

    /* if we have a destination file for all the cookies to get dumped to */
    if(cookie_output(data->cookies, data->set.str[STRING_COOKIEJAR]))
      infof(data, "WARNING: failed to save cookies in %s\n",
            data->set.str[STRING_COOKIEJAR]);
  }
  else {
    if(cleanup && data->change.cookielist) {
      /* since nothing is written, we can just free the list of cookie file
         names */
      curl_slist_free_all(data->change.cookielist); /* clean up list */
      data->change.cookielist = NULL;
    }
    Curl_share_lock(data, CURL_LOCK_DATA_COOKIE, CURL_LOCK_ACCESS_SINGLE);
  }

  if(cleanup && (!data->share || (data->cookies != data->share->cookies))) {
    Curl_cookie_cleanup(data->cookies);
  }
  Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
}

#endif /* CURL_DISABLE_HTTP || CURL_DISABLE_COOKIES */