/*

**  Licensed to the Apache Software Foundation (ASF) under one or more

** contributor license agreements.  See the NOTICE file distributed with

** this work for additional information regarding copyright ownership.

** The ASF licenses this file to You under the Apache License, Version 2.0

** (the "License"); you may not use this file except in compliance with

** the License.  You may obtain a copy of the License at

**

**      http://www.apache.org/licenses/LICENSE-2.0

**

**  Unless required by applicable law or agreed to in writing, software

**  distributed under the License is distributed on an "AS IS" BASIS,

**  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

**  See the License for the specific language governing permissions and

**  limitations under the License.

*/

#include "apreq_error.h"

#include "apreq_parser.h"

#include "apreq_util.h"

#include "apr_strings.h"

#include "apr_xml.h"

#include "apr_hash.h"

#define PARSER_STATUS_CHECK(PREFIX)   do {         \

    if (ctx->status == PREFIX##_ERROR)             \

        return APREQ_ERROR_GENERAL;                \

    else if (ctx->status == PREFIX##_COMPLETE)     \

        return APR_SUCCESS;                        \

    else if (bb == NULL)                           \

        return APR_INCOMPLETE;                     \

} while (0);

APREQ_DECLARE(apreq_parser_t *) apreq_parser_make(apr_pool_t *pool,

                                                  apr_bucket_alloc_t *ba,

                                                  const char *content_type,

                                                  apreq_parser_function_t pfn,

                                                  apr_size_t brigade_limit,

                                                  const char *temp_dir,

                                                  apreq_hook_t *hook,

                                                  void *ctx)

{

    apreq_parser_t *p = apr_palloc(pool, sizeof *p);

    p->content_type = content_type;

    p->parser = pfn;

    p->hook = hook;

    p->pool = pool;

    p->bucket_alloc = ba;

    p->brigade_limit = brigade_limit;

    p->temp_dir = temp_dir;

    p->ctx = ctx;

    return p;

}

APREQ_DECLARE(apreq_hook_t *) apreq_hook_make(apr_pool_t *pool,

                                              apreq_hook_function_t hook,

                                              apreq_hook_t *next,

                                              void *ctx)

{

    apreq_hook_t *h = apr_palloc(pool, sizeof *h);

    h->hook = hook;

    h->next = next;

    h->pool = pool;

    h->ctx = ctx;

    return h;

}

/*XXX this may need to check the parser's state before modifying the hook list */

APREQ_DECLARE(apr_status_t) apreq_parser_add_hook(apreq_parser_t *p,

                                                  apreq_hook_t *h)

{

    apreq_hook_t *last = h;

    while (last->next)

        last = last->next;

    last->next = p->hook;

    p->hook = h;

    return APR_SUCCESS;

}

static int default_parsers_lock = 0;

static apr_hash_t *default_parsers = NULL;

static apr_pool_t *default_parser_pool = NULL;

static apr_status_t apreq_parsers_cleanup(void *data)

{

    default_parsers_lock = 0;

    default_parsers = NULL;

    default_parser_pool = NULL;

    return APR_SUCCESS;

}

APREQ_DECLARE(apr_status_t) apreq_pre_initialize(apr_pool_t *pool)

{

    apr_status_t status;

    if (default_parser_pool != NULL)

        return APR_SUCCESS;

    if (default_parsers_lock)

        return APREQ_ERROR_GENERAL;

    status = apr_pool_create(&default_parser_pool, pool);

    if (status != APR_SUCCESS)

        return status;

    apr_pool_tag(default_parser_pool, "apreq_default_parser");

    apr_pool_cleanup_register(default_parser_pool, NULL,

                              apreq_parsers_cleanup,

                              apr_pool_cleanup_null);

    default_parsers = apr_hash_make(default_parser_pool);

    apreq_register_parser("application/x-www-form-urlencoded",

                          apreq_parse_urlencoded);

    apreq_register_parser("multipart/form-data", apreq_parse_multipart);

    apreq_register_parser("multipart/related", apreq_parse_multipart);

    return APR_SUCCESS;

}

APREQ_DECLARE(apr_status_t) apreq_post_initialize(apr_pool_t *pool)

{

    (void)pool;

    if (default_parser_pool == NULL)

        return APREQ_ERROR_GENERAL;

    default_parsers_lock = 1;

    return APR_SUCCESS;

}

APREQ_DECLARE(apr_status_t) apreq_initialize(apr_pool_t *pool)

{

    apr_status_t s = apreq_pre_initialize(pool);

    if (s != APR_SUCCESS)

        return s;

    return apreq_post_initialize(pool);

}

APREQ_DECLARE(apr_status_t) apreq_register_parser(const char *enctype,

                                                  apreq_parser_function_t pfn)

{

    apreq_parser_function_t *f = NULL;

    if (default_parsers == NULL)

        return APR_EINIT;

    if (enctype == NULL)

        return APR_EINVAL;

    if (default_parsers_lock)

        return APREQ_ERROR_GENERAL;

    if (pfn != NULL) {

        f = apr_palloc(default_parser_pool, sizeof *f);

        *f = pfn;

    }

    apr_hash_set(default_parsers, apr_pstrdup(default_parser_pool, enctype),

                 APR_HASH_KEY_STRING, f);

    return APR_SUCCESS;

}

APREQ_DECLARE(apreq_parser_function_t)apreq_parser(const char *enctype)

{

    apreq_parser_function_t *f;

    apr_size_t tlen = 0;

    if (enctype == NULL || default_parsers_lock == 0)

        return NULL;

    while (enctype[tlen] && enctype[tlen] != ';')

        ++tlen;

    f = apr_hash_get(default_parsers, enctype, tlen);

    if (f != NULL)

        return *f;

    else

        return NULL;

}

APREQ_DECLARE_HOOK(apreq_hook_disable_uploads)

{

    return (bb == NULL) ? APR_SUCCESS : APREQ_ERROR_GENERAL;

}

APREQ_DECLARE_HOOK(apreq_hook_discard_brigade)

{

    apr_status_t s = APR_SUCCESS;

    if (hook->next)

        s = apreq_hook_run(hook->next, param, bb);

    if (bb != NULL)

        apr_brigade_cleanup(bb);

    return s;

}

/* generic parser */

struct gen_ctx {

    apreq_param_t               *param;

    enum {

        GEN_INCOMPLETE,

        GEN_COMPLETE,

        GEN_ERROR

    }                            status;

};

APREQ_DECLARE_PARSER(apreq_parse_generic)

{

    struct gen_ctx *ctx = parser->ctx;

    apr_pool_t *pool = parser->pool;

    apr_status_t s = APR_SUCCESS;

    apr_bucket *e = APR_BRIGADE_LAST(bb);

    unsigned saw_eos = 0;

    if (ctx == NULL) {

        parser->ctx = ctx = apr_palloc(pool, sizeof *ctx);

        ctx->status = GEN_INCOMPLETE;

        ctx->param = apreq_param_make(pool,

                                      "_dummy_", strlen("_dummy_"), "", 0);

        if (ctx->param == NULL)

            return APR_ENOMEM;

        ctx->param->upload = apr_brigade_create(pool, parser->bucket_alloc);

        ctx->param->info = apr_table_make(pool, APREQ_DEFAULT_NELTS);

    }

    PARSER_STATUS_CHECK(GEN);

    while (e != APR_BRIGADE_SENTINEL(bb)) {

        if (APR_BUCKET_IS_EOS(e)) {

            saw_eos = 1;

            break;

        }

        e = APR_BUCKET_PREV(e);

    }

    if (parser->hook != NULL) {

        s = apreq_hook_run(parser->hook, ctx->param, bb);

        if (s != APR_SUCCESS) {

            ctx->status = GEN_ERROR;

            return s;

        }

    }

    apreq_brigade_setaside(bb, pool);

    s = apreq_brigade_concat(pool, parser->temp_dir, parser->brigade_limit,

                             ctx->param->upload, bb);

    if (s != APR_SUCCESS) {

        ctx->status = GEN_ERROR;

        return s;

    }

    if (saw_eos) {

        ctx->status = GEN_COMPLETE;

        return APR_SUCCESS;

    }

    else

        return APR_INCOMPLETE;

}

struct xml_ctx {

    apr_xml_doc                 *doc;

    apr_xml_parser              *xml_parser;

    enum {

        XML_INCOMPLETE,

        XML_COMPLETE,

        XML_ERROR

    }                            status;

};

APREQ_DECLARE_HOOK(apreq_hook_apr_xml_parser)

{

    apr_pool_t *pool = hook->pool;

    struct xml_ctx *ctx = hook->ctx;

    apr_status_t s = APR_SUCCESS;

    apr_bucket *e;

    if (ctx == NULL) {

        hook->ctx = ctx = apr_palloc(pool, sizeof *ctx);

        ctx->doc = NULL;

        ctx->xml_parser = apr_xml_parser_create(pool);

        ctx->status = XML_INCOMPLETE;

    }

    PARSER_STATUS_CHECK(XML);

    for (e = APR_BRIGADE_FIRST(bb); e != APR_BRIGADE_SENTINEL(bb);

         e = APR_BUCKET_NEXT(e))

    {

        const char *data;

        apr_size_t dlen;

        if (APR_BUCKET_IS_EOS(e)) {

            s = apr_xml_parser_done(ctx->xml_parser, &ctx->doc);

            if (s == APR_SUCCESS) {

                ctx->status = XML_COMPLETE;

                if (hook->next)

                    s = apreq_hook_run(hook->next, param, bb);

            }

            else {

                ctx->status = XML_ERROR;

            }

            return s;

        }

        else if (APR_BUCKET_IS_METADATA(e)) {

            continue;

        }

        s = apr_bucket_read(e, &data, &dlen, APR_BLOCK_READ);

        if (s != APR_SUCCESS) {

            ctx->status = XML_ERROR;

            return s;

        }

        s = apr_xml_parser_feed(ctx->xml_parser, data, dlen);

        if (s != APR_SUCCESS) {

            ctx->status = XML_ERROR;

            return s;

        }

    }

    if (hook->next)

        return apreq_hook_run(hook->next, param, bb);

    return APR_SUCCESS;

}

APREQ_DECLARE_HOOK(apreq_hook_find_param)

{

    apreq_hook_find_param_ctx_t *ctx = hook->ctx;

    int is_final = (bb == NULL) || APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(bb));

    apr_status_t s = (hook->next == NULL)

        ? APR_SUCCESS : apreq_hook_run(hook->next, param, bb);

    if (is_final && s == APR_SUCCESS && ctx->param == NULL

        && strcasecmp(ctx->name, param->v.name) == 0) {

        ctx->param = param;

        ctx->prev->next = hook->next;

    }

    return s;

}