/*      $OpenBSD: pf_ruleset.c,v 1.22 2025/07/07 02:28:50 jsg 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/param.h>
#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/pool.h>
#endif /* _KERNEL */
#include <sys/syslog.h>

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

#ifdef _KERNEL
#define rs_malloc(x)            malloc(x, M_PF, M_WAITOK|M_CANFAIL|M_ZERO)
#define rs_free(x, siz)         free(x, M_PF, siz)
#define rs_pool_get_anchor()    pool_get(&pf_anchor_pl, \
                                    PR_WAITOK|PR_LIMITFAIL|PR_ZERO)
#define rs_pool_put_anchor(x)   pool_put(&pf_anchor_pl, x)

struct pool     pf_anchor_pl;

#else   /* !_KERNEL */
/* 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)            calloc(1, x)
#define rs_free(x, siz)         freezero(x, siz)
#define rs_pool_get_anchor()    calloc(1, sizeof(struct pf_anchor))
#define rs_pool_put_anchor(x)   freezero(x, sizeof(struct pf_anchor))

#ifdef PFDEBUG
#include <sys/stdarg.h> /* for DPFPRINTF() */
#endif  /* PFDEBUG */
#endif /* _KERNEL */


struct pf_anchor_global  pf_anchors;
struct pf_anchor         pf_main_anchor;

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);
}

void
pf_init_ruleset(struct pf_ruleset *ruleset)
{
        memset(ruleset, 0, sizeof(struct pf_ruleset));
        TAILQ_INIT(&ruleset->rules.queues[0]);
        TAILQ_INIT(&ruleset->rules.queues[1]);
        ruleset->rules.active.ptr = &ruleset->rules.queues[0];
        ruleset->rules.inactive.ptr = &ruleset->rules.queues[1];
}

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

        key = rs_malloc(sizeof(*key));
        if (key == NULL)
                return (NULL);
        strlcpy(key->path, path, sizeof(key->path));
        found = RB_FIND(pf_anchor_global, &pf_anchors, key);
        rs_free(key, sizeof(*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_get_leaf_ruleset(char *path, char **path_remainder)
{
        struct pf_ruleset       *ruleset;
        char                    *leaf, *p;
        int                      i = 0;

        p = path;
        while (*p == '/')
                p++;

        ruleset = pf_find_ruleset(p);
        leaf = p;
        while (ruleset == NULL) {
                leaf = strrchr(p, '/');
                if (leaf != NULL) {
                        *leaf = '\0';
                        i++;
                        ruleset = pf_find_ruleset(p);
                } else {
                        leaf = path;
                        /*
                         * if no path component exists, then main ruleset is
                         * our parent.
                         */
                        ruleset = &pf_main_ruleset;
                }
        }

        if (path_remainder != NULL)
                *path_remainder = leaf;

        /* restore slashes in path.  */
        while (i != 0) {
                while (*leaf != '\0')
                        leaf++;
                *leaf = '/';
                i--;
        }

        return (ruleset);
}

struct pf_anchor *
pf_create_anchor(struct pf_anchor *parent, const char *aname)
{
        struct pf_anchor        *anchor, *dup;

        if (!*aname || (strlen(aname) >= PF_ANCHOR_NAME_SIZE) ||
            ((parent != NULL) && (strlen(parent->path) >= PF_ANCHOR_MAXPATH)))
                return (NULL);

        anchor = rs_pool_get_anchor();
        if (anchor == NULL)
                return (NULL);

        RB_INIT(&anchor->children);
        strlcpy(anchor->name, aname, sizeof(anchor->name));
        if (parent != NULL) {
                /*
                 * Make sure path for levels 2, 3, ... is terminated by '/':
                 *      1/2/3/...
                 */
                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) {
                DPFPRINTF(LOG_NOTICE,
                    "%s: RB_INSERT to global '%s' '%s' collides with '%s' '%s'",
                    __func__, anchor->path, anchor->name, dup->path, dup->name);
                rs_pool_put_anchor(anchor);
                return (NULL);
        }

        if (parent != NULL) {
                anchor->parent = parent;
                dup = RB_INSERT(pf_anchor_node, &parent->children, anchor);
                if (dup != NULL) {
                        DPFPRINTF(LOG_NOTICE,
                            "%s: RB_INSERT to parent '%s' '%s' collides with "
                            "'%s' '%s'", __func__, anchor->path, anchor->name,
                            dup->path, dup->name);
                        RB_REMOVE(pf_anchor_global, &pf_anchors,
                            anchor);
                        rs_pool_put_anchor(anchor);
                        return (NULL);
                }
        }

        pf_init_ruleset(&anchor->ruleset);
        anchor->ruleset.anchor = anchor;
#ifdef  _KERNEL
        refcnt_init(&anchor->ref);
#endif

        return (anchor);
}

struct pf_ruleset *
pf_find_or_create_ruleset(const char *path)
{
        char                    *p, *aname, *r;
        struct pf_ruleset       *ruleset;
        struct pf_anchor        *anchor;

        if (path[0] == 0)
                return (&pf_main_ruleset);

        while (*path == '/')
                path++;

        ruleset = pf_find_ruleset(path);
        if (ruleset != NULL)
                return (ruleset);

        p = rs_malloc(MAXPATHLEN);
        if (p == NULL)
                return (NULL);
        strlcpy(p, path, MAXPATHLEN);

        ruleset = pf_get_leaf_ruleset(p, &aname);
        anchor = ruleset->anchor;

        while (*aname == '/')
                aname++;
        /*
         * aname is a path remainder, which contains nodes we must create.  We
         * process the aname path from left to right, effectively descending
         * from parents to children.
         */
        while ((r = strchr(aname, '/')) != NULL || *aname) {
                if (r != NULL)
                        *r = 0;

                anchor = pf_create_anchor(anchor, aname);
                if (anchor == NULL) {
                        rs_free(p, MAXPATHLEN);
                        return (NULL);
                }

                if (r == NULL)
                        break;
                else
                        aname = r + 1;
        }

        rs_free(p, MAXPATHLEN);
        return (&anchor->ruleset);
}

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

        while (ruleset != NULL) {
                if (ruleset == &pf_main_ruleset ||
                    !RB_EMPTY(&ruleset->anchor->children) ||
                    ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
                    ruleset->topen)
                        return;
                if (!TAILQ_EMPTY(ruleset->rules.active.ptr) ||
                    !TAILQ_EMPTY(ruleset->rules.inactive.ptr) ||
                    ruleset->rules.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);
                pf_anchor_rele(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 = rs_malloc(MAXPATHLEN);
        if (path == NULL)
                return (1);
        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]) {
                                DPFPRINTF(LOG_NOTICE,
                                    "pf_anchor_setup: .. beyond root");
                                rs_free(path, MAXPATHLEN);
                                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, MAXPATHLEN);
        if (ruleset == NULL || ruleset == &pf_main_ruleset) {
                DPFPRINTF(LOG_NOTICE,
                    "pf_anchor_setup: ruleset");
                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 = rs_malloc(MAXPATHLEN);
                if (a == NULL)
                        return (1);
                if (rs == &pf_main_ruleset)
                        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))) {
                        DPFPRINTF(LOG_NOTICE,
                            "pf_anchor_copyout: '%s' '%s'", a,
                            r->anchor->path);
                        rs_free(a, MAXPATHLEN);
                        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, MAXPATHLEN);
        }
        if (r->anchor_wildcard)
                strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
                    sizeof(pr->anchor_call));
        return (0);
}

void
pf_remove_anchor(struct pf_rule *r)
{
        if (r->anchor == NULL)
                return;
        if (r->anchor->refcnt <= 0)
                DPFPRINTF(LOG_NOTICE, "pf_remove_anchor: broken refcount");
        else if (!--r->anchor->refcnt)
                pf_remove_if_empty_ruleset(&r->anchor->ruleset);
        r->anchor = NULL;
}

void
pf_anchor_rele(struct pf_anchor *anchor)
{
        if ((anchor == NULL) || (anchor == &pf_main_anchor))
                return;

#ifdef  _KERNEL
        if (refcnt_rele(&anchor->ref))
                rs_pool_put_anchor(anchor);
#else
        rs_pool_put_anchor(anchor);
#endif
}

struct pf_anchor *
pf_anchor_take(struct pf_anchor *anchor)
{
#ifdef  _KERNEL
        if (anchor != NULL && anchor != &pf_main_anchor)
                refcnt_take(&anchor->ref);
#endif
        return (anchor);
}