source: protocols/oscar/msgcookie.c @ 0843bbe

/*
 * Cookie Caching stuff. Adam wrote this, apparently just some
 * derivatives of n's SNAC work. I cleaned it up, added comments.
 *
 */

/*
 * I'm assuming that cookies are type-specific. that is, we can have
 * "1234578" for type 1 and type 2 concurrently. if i'm wrong, then we
 * lose some error checking. if we assume cookies are not type-specific and are
 * wrong, we get quirky behavior when cookies step on each others' toes.
 */

#include <aim.h>
#include "info.h"

/**
 * aim_cachecookie - appends a cookie to the cookie list
 * @sess: session to add to
 * @cookie: pointer to struct to append
 *
 * if cookie->cookie for type cookie->type is found, updates the
 * ->addtime of the found structure; otherwise adds the given cookie
 * to the cache
 *
 * returns -1 on error, 0 on append, 1 on update.  the cookie you pass
 * in may be free'd, so don't count on its value after calling this!
 *
 */
int aim_cachecookie(aim_session_t *sess, aim_msgcookie_t *cookie)
{
        aim_msgcookie_t *newcook;

        if (!sess || !cookie) {
                return -EINVAL;
        }

        newcook = aim_checkcookie(sess, cookie->cookie, cookie->type);

        if (newcook == cookie) {
                newcook->addtime = time(NULL);
                return 1;
        } else if (newcook) {
                aim_cookie_free(sess, newcook);
        }

        cookie->addtime = time(NULL);

        cookie->next = sess->msgcookies;
        sess->msgcookies = cookie;

        return 0;
}

/**
 * aim_uncachecookie - grabs a cookie from the cookie cache (removes it from the list)
 * @sess: session to grab cookie from
 * @cookie: cookie string to look for
 * @type: cookie type to look for
 *
 * takes a cookie string and a cookie type and finds the cookie struct associated with that duple, removing it from the cookie list ikn the process.
 *
 * if found, returns the struct; if none found (or on error), returns NULL:
 */
aim_msgcookie_t *aim_uncachecookie(aim_session_t *sess, guint8 *cookie, int type)
{
        aim_msgcookie_t *cur, **prev;

        if (!cookie || !sess->msgcookies) {
                return NULL;
        }

        for (prev = &sess->msgcookies; (cur = *prev); ) {
                if ((cur->type == type) &&
                    (memcmp(cur->cookie, cookie, 8) == 0)) {
                        *prev = cur->next;
                        return cur;
                }
                prev = &cur->next;
        }

        return NULL;
}

/**
 * aim_mkcookie - generate an aim_msgcookie_t *struct from a cookie string, a type, and a data pointer.
 * @c: pointer to the cookie string array
 * @type: cookie type to use
 * @data: data to be cached with the cookie
 *
 * returns NULL on error, a pointer to the newly-allocated cookie on
 * success.
 *
 */
aim_msgcookie_t *aim_mkcookie(guint8 *c, int type, void *data)
{
        aim_msgcookie_t *cookie;

        if (!c) {
                return NULL;
        }

        if (!(cookie = g_new0(aim_msgcookie_t, 1))) {
                return NULL;
        }

        cookie->data = data;
        cookie->type = type;
        memcpy(cookie->cookie, c, 8);

        return cookie;
}

/**
 * aim_checkcookie - check to see if a cookietuple has been cached
 * @sess: session to check for the cookie in
 * @cookie: pointer to the cookie string array
 * @type: type of the cookie to look for
 *
 * this returns a pointer to the cookie struct (still in the list) on
 * success; returns NULL on error/not found
 *
 */

aim_msgcookie_t *aim_checkcookie(aim_session_t *sess, const guint8 *cookie, int type)
{
        aim_msgcookie_t *cur;

        for (cur = sess->msgcookies; cur; cur = cur->next) {
                if ((cur->type == type) &&
                    (memcmp(cur->cookie, cookie, 8) == 0)) {
                        return cur;
                }
        }

        return NULL;
}

/**
 * aim_cookie_free - free an aim_msgcookie_t struct
 * @sess: session to remove the cookie from
 * @cookiep: the address of a pointer to the cookie struct to remove
 *
 * this function removes the cookie *cookie from the list of cookies
 * in sess, and then frees all memory associated with it. including
 * its data! if you want to use the private data after calling this,
 * make sure you copy it first.
 *
 * returns -1 on error, 0 on success.
 *
 */
int aim_cookie_free(aim_session_t *sess, aim_msgcookie_t *cookie)
{
        aim_msgcookie_t *cur, **prev;

        if (!sess || !cookie) {
                return -EINVAL;
        }

        for (prev = &sess->msgcookies; (cur = *prev); ) {
                if (cur == cookie) {
                        *prev = cur->next;
                } else {
                        prev = &cur->next;
                }
        }

        g_free(cookie->data);
        g_free(cookie);

        return 0;
}