src/server/safs/pathcheck.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2013 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. 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 HOLDER 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.
 */

#include <cx/string.h>

#include "pathcheck.h"

#include "../util/pblock.h"
#include "../daemon/config.h"
#include "../daemon/acl.h"
#include "../daemon/acldata.h"
#include "../daemon/session.h"
#include "../daemon/vserver.h"

#include "../daemon/vfs.h"

#include "../config/acl.h"

#define PATHCHECK_MAX_TOKENS 2048

int require_auth(pblock *pb, Session *sn, Request *rq) {
    char *user = pblock_findkeyval(pb_key_auth_user, rq->vars);

    if(user == NULL) {
        pblock_nvinsert(
                "www-authenticate",
                "Basic realm=\"Webserver\"",
                rq->srvhdrs);

        protocol_status(sn, rq, PROTOCOL_UNAUTHORIZED, NULL);
        return REQ_ABORTED;
    }

    return REQ_PROCEED;
}

int require_access(pblock *pb, Session *sn, Request *rq) {
    char *mask_str = pblock_findval("mask", pb);
    if(!mask_str) {
        log_ereport(LOG_MISCONFIG, "require-access: missing mask parameter");
        protocol_status(sn, rq, 500, NULL);
        return REQ_ABORTED;
    }
    
    char *method = pblock_findval("method", pb);
    if(method) {
        char *m = pblock_findkeyval(pb_key_method, rq->reqpb);
        if(strcmp(method, m)) {
            return REQ_NOACTION;
        }
    }
    
    uint32_t access_mask = 0;
    cxstring *rights = NULL;
    ssize_t n = cx_strsplit_a(pool_allocator(sn->pool), cx_str(mask_str), (cxstring){",", 1}, PATHCHECK_MAX_TOKENS, &rights);
    for(int i=0;i<n;i++) {
        cxstring right = rights[i];
        access_mask = access_mask | accstr2int(right);
    }
    pool_free(sn->pool, rights);
    
    rq->aclreqaccess = access_mask;
    
    return REQ_PROCEED;
}

int append_acl(pblock *pb, Session *sn, Request *rq) {
    const VirtualServer *vs = request_get_vs(rq);
    
    WS_ASSERT(vs);
    
    char *aclname = pblock_findval("acl", pb);
    if(aclname) {
        ACLList *acl = acl_get(vs->acls, aclname);
        if(!acl) {
            log_ereport(
                    LOG_MISCONFIG,
                    "append-acl: acl %s not found", aclname);
            protocol_status(sn, rq, 500, NULL);
            return REQ_ABORTED;
        }
        
        acllist_append(sn, rq, acl);
    }
    
    return REQ_PROCEED;
}


int check_acl(pblock *pb, Session *sn, Request *rq) {
    int access_mask = ACL_READ_DATA | rq->aclreqaccess; // TODO: check method and path
    
    int ret = acl_evaluate(sn, rq, access_mask);
    if(ret == REQ_ABORTED) {
        // TODO: status, error, ...
        return REQ_ABORTED;
    }
    
    return REQ_PROCEED;
}

int find_index(pblock *pb, Session *sn, Request *rq) {
    char *inames = pblock_findval("index-names", pb);
    if(!inames) {
        log_ereport(
                LOG_MISCONFIG,
                "find-index: index-names parameter missing");
        return REQ_ABORTED;
    }
    
    cxstring *names = NULL;
    ssize_t ni = cx_strsplit_a(pool_allocator(sn->pool), cx_str(inames), (cxstring)CX_STR(","), PATHCHECK_MAX_TOKENS, &names);
    if(ni <= 0) {
        log_ereport(
                LOG_MISCONFIG,
                "find-index: no files specified in index-names parameter");
        return REQ_ABORTED;
    }
    
    // only find index for GET requests
    // maybe we want to support find-index for other methods, in that case
    // we should implement a parameter for this
    char *method = pblock_findkeyval(pb_key_method, rq->reqpb);
    if(strcmp(method, "GET")) {
        return REQ_NOACTION;
    }
    
    VFSContext *vfs = vfs_request_context(sn, rq);
    int ret = REQ_NOACTION;
    
    char *path = pblock_findkeyval(pb_key_path, rq->vars);
    size_t pathlen = strlen(path);
    cxstring p = cx_strn(path, pathlen);
    if(path[pathlen-1] == '/') {
        for(int i=0;i<ni;i++) {
            cxmutstr newpath = cx_strcat(2, p, cx_strtrim(names[i]));
            struct stat s;
            if(!vfs_stat(vfs, newpath.ptr, &s)) {
                pblock_kvinsert(
                        pb_key_path,
                        newpath.ptr,
                        newpath.length,
                        rq->vars);
                free(newpath.ptr);
                ret = REQ_PROCEED;
            } else {
                free(newpath.ptr);
            }
        }
    }
    
    pool_free(sn->pool, names);
    
    return ret;
}

int dir_redirect(pblock *pb, Session *sn, Request *rq) {
    char *path = pblock_findkeyval(pb_key_path, rq->vars);
    
    VFSContext *vfs = vfs_request_context(sn, rq);
    
    struct stat s;
    if(vfs_stat(vfs, path, &s) != 0) {
        return REQ_NOACTION;
    }
    
    // TODO: remove code duplication (service.c)
    // TODO: make response code configurable
    if(S_ISDIR(s.st_mode) && path[strlen(path)-1] != '/') {
        pblock_nvinsert("content-length", "0", rq->srvhdrs);
        pblock_removekey(pb_key_content_type, rq->srvhdrs);
        char *uri = pblock_findkeyval(pb_key_uri, rq->reqpb);
        size_t urilen = strlen(uri);
        char *location = pool_malloc(sn->pool, urilen + 2);
        memcpy(location, uri, urilen);
        location[urilen] = '/';
        location[urilen+1] = '\0';
        pblock_kvinsert(pb_key_location, location, urilen + 1, rq->srvhdrs);
        protocol_status(sn, rq, 302, NULL);
        http_start_response(sn, rq);
        return REQ_ABORTED;
    }
    
    return REQ_PROCEED;
}