/*      $NetBSD: pf_ruleset.c,v 1.2 2008/06/18 09:06:27 yamt Exp $ */
/*      $OpenBSD: pf_ruleset.c,v 1.1 2006/10/27 13:56:51 mcbride Exp $ */

/*
 * Copyright (c) 2001 Daniel Hartmeier
 * Copyright (c) 2002,2003 Henning Brauer
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    - Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    - Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Effort sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F30602-01-2-0537.
 *
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pf_ruleset.c,v 1.2 2008/06/18 09:06:27 yamt Exp $");

#include <sys/param.h>
#include <sys/socket.h>
#ifdef _KERNEL
# include <sys/systm.h>
#endif /* _KERNEL */
#include <sys/mbuf.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

#include <net/if.h>
#include <net/pfvar.h>

#ifdef INET6
#include <netinet/ip6.h>
#endif /* INET6 */


#ifdef _KERNEL
# define DPFPRINTF(format, x...)                \
        if (pf_status.debug >= PF_DEBUG_NOISY)  \
                printf(format , ##x)
#define rs_malloc(x)            malloc(x, M_TEMP, M_WAITOK)
#define rs_free(x)              free(x, M_TEMP)

#else
/* Userland equivalents so we can lend code to pfctl et al. */

# include <arpa/inet.h>
# include <errno.h>
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# define rs_malloc(x)            malloc(x)
# define rs_free(x)              free(x)

# ifdef PFDEBUG
#  include <sys/stdarg.h>
#  define DPFPRINTF(format, x...)       fprintf(stderr, format , ##x)
# else
#  define DPFPRINTF(format, x...)       ((void)0)
# endif /* PFDEBUG */
#endif /* _KERNEL */


struct pf_anchor_global  pf_anchors;
struct pf_anchor         pf_main_anchor;

int                      pf_get_ruleset_number(u_int8_t);
void                     pf_init_ruleset(struct pf_ruleset *);
int                      pf_anchor_setup(struct pf_rule *,
                            const struct pf_ruleset *, const char *);
int                      pf_anchor_copyout(const struct pf_ruleset *,
                            const struct pf_rule *, struct pfioc_rule *);
void                     pf_anchor_remove(struct pf_rule *);

static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);

RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);

static __inline int
pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
{
        int c = strcmp(a->path, b->path);

        return (c ? (c < 0 ? -1 : 1) : 0);
}

int
pf_get_ruleset_number(u_int8_t action)
{
        switch (action) {
        case PF_SCRUB:
        case PF_NOSCRUB:
                return (PF_RULESET_SCRUB);
                break;
        case PF_PASS:
        case PF_DROP:
                return (PF_RULESET_FILTER);
                break;
        case PF_NAT:
        case PF_NONAT:
                return (PF_RULESET_NAT);
                break;
        case PF_BINAT:
        case PF_NOBINAT:
                return (PF_RULESET_BINAT);
                break;
        case PF_RDR:
        case PF_NORDR:
                return (PF_RULESET_RDR);
                break;
        default:
                return (PF_RULESET_MAX);
                break;
        }
}

void
pf_init_ruleset(struct pf_ruleset *ruleset)
{
        int     i;

        memset(ruleset, 0, sizeof(struct pf_ruleset));
        for (i = 0; i < PF_RULESET_MAX; i++) {
                TAILQ_INIT(&ruleset->rules[i].queues[0]);
                TAILQ_INIT(&ruleset->rules[i].queues[1]);
                ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
                ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
        }
}

struct pf_anchor *
pf_find_anchor(const char *path)
{
        struct pf_anchor        *key, *found;

        key = (struct pf_anchor *)rs_malloc(sizeof(*key));
        memset(key, 0, sizeof(*key));
        strlcpy(key->path, path, sizeof(key->path));
        found = RB_FIND(pf_anchor_global, &pf_anchors, key);
        rs_free(key);
        return (found);
}

struct pf_ruleset *
pf_find_ruleset(const char *path)
{
        struct pf_anchor        *anchor;

        while (*path == '/')
                path++;
        if (!*path)
                return (&pf_main_ruleset);
        anchor = pf_find_anchor(path);
        if (anchor == NULL)
                return (NULL);
        else
                return (&anchor->ruleset);
}

struct pf_ruleset *
pf_find_or_create_ruleset(const char *path)
{
        char                    *p, *q, *r;
        struct pf_ruleset       *ruleset;
        struct pf_anchor        *anchor = NULL /* XXX gcc */;
        struct pf_anchor        *dup, *parent = NULL;

        if (path[0] == 0)
                return (&pf_main_ruleset);
        while (*path == '/')
                path++;
        ruleset = pf_find_ruleset(path);
        if (ruleset != NULL)
                return (ruleset);
        p = (char *)rs_malloc(MAXPATHLEN);
        bzero(p, MAXPATHLEN);
        strlcpy(p, path, MAXPATHLEN);
        while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
                *q = 0;
                if ((ruleset = pf_find_ruleset(p)) != NULL) {
                        parent = ruleset->anchor;
                        break;
                }
        }
        if (q == NULL)
                q = p;
        else
                q++;
        strlcpy(p, path, MAXPATHLEN);
        if (!*q) {
                rs_free(p);
                return (NULL);
        }
        while ((r = strchr(q, '/')) != NULL || *q) {
                if (r != NULL)
                        *r = 0;
                if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
                    (parent != NULL && strlen(parent->path) >=
                    MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
                        rs_free(p);
                        return (NULL);
                }
                anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
                if (anchor == NULL) {
                        rs_free(p);
                        return (NULL);
                }
                memset(anchor, 0, sizeof(*anchor));
                RB_INIT(&anchor->children);
                strlcpy(anchor->name, q, sizeof(anchor->name));
                if (parent != NULL) {
                        strlcpy(anchor->path, parent->path,
                            sizeof(anchor->path));
                        strlcat(anchor->path, "/", sizeof(anchor->path));
                }
                strlcat(anchor->path, anchor->name, sizeof(anchor->path));
                if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
                    NULL) {
                        printf("pf_find_or_create_ruleset: RB_INSERT1 "
                            "'%s' '%s' collides with '%s' '%s'\n",
                            anchor->path, anchor->name, dup->path, dup->name);
                        rs_free(anchor);
                        rs_free(p);
                        return (NULL);
                }
                if (parent != NULL) {
                        anchor->parent = parent;
                        if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
                            anchor)) != NULL) {
                                printf("pf_find_or_create_ruleset: "
                                    "RB_INSERT2 '%s' '%s' collides with "
                                    "'%s' '%s'\n", anchor->path, anchor->name,
                                    dup->path, dup->name);
                                RB_REMOVE(pf_anchor_global, &pf_anchors,
                                    anchor);
                                rs_free(anchor);
                                rs_free(p);
                                return (NULL);
                        }
                }
                pf_init_ruleset(&anchor->ruleset);
                anchor->ruleset.anchor = anchor;
                parent = anchor;
                if (r != NULL)
                        q = r + 1;
                else
                        *q = 0;
        }
        rs_free(p);
        return (&anchor->ruleset);
}

void
pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
{
        struct pf_anchor        *parent;
        int                      i;

        while (ruleset != NULL) {
                if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
                    !RB_EMPTY(&ruleset->anchor->children) ||
                    ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
                    ruleset->topen)
                        return;
                for (i = 0; i < PF_RULESET_MAX; ++i)
                        if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
                            !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
                            ruleset->rules[i].inactive.open)
                                return;
                RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
                if ((parent = ruleset->anchor->parent) != NULL)
                        RB_REMOVE(pf_anchor_node, &parent->children,
                            ruleset->anchor);
                rs_free(ruleset->anchor);
                if (parent == NULL)
                        return;
                ruleset = &parent->ruleset;
        }
}

int
pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
    const char *name)
{
        char                    *p, *path;
        struct pf_ruleset       *ruleset;

        r->anchor = NULL;
        r->anchor_relative = 0;
        r->anchor_wildcard = 0;
        if (!name[0])
                return (0);
        path = (char *)rs_malloc(MAXPATHLEN);
        bzero(path, MAXPATHLEN);
        if (name[0] == '/')
                strlcpy(path, name + 1, MAXPATHLEN);
        else {
                /* relative path */
                r->anchor_relative = 1;
                if (s->anchor == NULL || !s->anchor->path[0])
                        path[0] = 0;
                else
                        strlcpy(path, s->anchor->path, MAXPATHLEN);
                while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
                        if (!path[0]) {
                                printf("pf_anchor_setup: .. beyond root\n");
                                rs_free(path);
                                return (1);
                        }
                        if ((p = strrchr(path, '/')) != NULL)
                                *p = 0;
                        else
                                path[0] = 0;
                        r->anchor_relative++;
                        name += 3;
                }
                if (path[0])
                        strlcat(path, "/", MAXPATHLEN);
                strlcat(path, name, MAXPATHLEN);
        }
        if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
                r->anchor_wildcard = 1;
                *p = 0;
        }
        ruleset = pf_find_or_create_ruleset(path);
        rs_free(path);
        if (ruleset == NULL || ruleset->anchor == NULL) {
                printf("pf_anchor_setup: ruleset\n");
                return (1);
        }
        r->anchor = ruleset->anchor;
        r->anchor->refcnt++;
        return (0);
}

int
pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
    struct pfioc_rule *pr)
{
        pr->anchor_call[0] = 0;
        if (r->anchor == NULL)
                return (0);
        if (!r->anchor_relative) {
                strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
                strlcat(pr->anchor_call, r->anchor->path,
                    sizeof(pr->anchor_call));
        } else {
                char    *a, *p;
                int      i;

                a = (char *)rs_malloc(MAXPATHLEN);
                bzero(a, MAXPATHLEN);
                if (rs->anchor == NULL)
                        a[0] = 0;
                else
                        strlcpy(a, rs->anchor->path, MAXPATHLEN);
                for (i = 1; i < r->anchor_relative; ++i) {
                        if ((p = strrchr(a, '/')) == NULL)
                                p = a;
                        *p = 0;
                        strlcat(pr->anchor_call, "../",
                            sizeof(pr->anchor_call));
                }
                if (strncmp(a, r->anchor->path, strlen(a))) {
                        printf("pf_anchor_copyout: '%s' '%s'\n", a,
                            r->anchor->path);
                        rs_free(a);
                        return (1);
                }
                if (strlen(r->anchor->path) > strlen(a))
                        strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
                            strlen(a) + 1 : 0), sizeof(pr->anchor_call));
                rs_free(a);
        }
        if (r->anchor_wildcard)
                strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
                    sizeof(pr->anchor_call));
        return (0);
}

void
pf_anchor_remove(struct pf_rule *r)
{
        if (r->anchor == NULL)
                return;
        if (r->anchor->refcnt <= 0) {
                printf("pf_anchor_remove: broken refcount\n");
                r->anchor = NULL;
                return;
        }
        if (!--r->anchor->refcnt)
                pf_remove_if_empty_ruleset(&r->anchor->ruleset);
        r->anchor = NULL;
}