rpluem at apache
May 1, 2008, 1:42 PM
Post #1 of 10
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Re: svn commit: r647263 - in /httpd/httpd/trunk: ./ docs/manual/mod/ include/ modules/aaa/ modules/filters/ modules/http/ server/
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On 04/11/2008 08:41 PM, minfrin[at]apache.org wrote:
> Author: minfrin
> Date: Fri Apr 11 11:41:53 2008
> New Revision: 647263
>
> URL: http://svn.apache.org/viewvc?rev=647263&view=rev
> Log:
> Move the KeptBodySize directive, kept_body filters and the
> ap_parse_request_body function out of the http module and into a
> new module called mod_request, reducing the size of the core.
>
> Added:
> httpd/httpd/trunk/docs/manual/mod/mod_request.xml (with props)
> httpd/httpd/trunk/include/mod_request.h (with props)
> httpd/httpd/trunk/modules/filters/mod_request.c (with props)
> Modified:
> httpd/httpd/trunk/CHANGES
> httpd/httpd/trunk/docs/manual/mod/core.xml
> httpd/httpd/trunk/docs/manual/mod/mod_include.xml
> httpd/httpd/trunk/include/http_protocol.h
> httpd/httpd/trunk/modules/aaa/mod_auth_form.c
> httpd/httpd/trunk/modules/filters/config.m4
> httpd/httpd/trunk/modules/http/http_core.c
> httpd/httpd/trunk/modules/http/http_filters.c
> httpd/httpd/trunk/modules/http/mod_core.h
> httpd/httpd/trunk/server/request.c
>
> Added: httpd/httpd/trunk/modules/filters/mod_request.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/filters/mod_request.c?rev=647263&view=auto
> ==============================================================================
> --- httpd/httpd/trunk/modules/filters/mod_request.c (added)
> +++ httpd/httpd/trunk/modules/filters/mod_request.c Fri Apr 11 11:41:53 2008
> +typedef struct keep_body_filter_ctx {
> + apr_off_t remaining;
> + apr_off_t keep_body;
> +} keep_body_ctx_t;
> +
> +/**
> + * This is the KEEP_BODY_INPUT filter for HTTP requests, for times when the
> + * body should be set aside for future use by other modules.
> + */
> +AP_DECLARE(apr_status_t) ap_keep_body_filter(ap_filter_t *f, apr_bucket_brigade *b,
> + ap_input_mode_t mode, apr_read_type_e block,
> + apr_off_t readbytes)
> +{
> + apr_bucket *e;
> + keep_body_ctx_t *ctx = f->ctx;
> + apr_status_t rv;
> + apr_bucket *bucket;
> + apr_off_t len = 0;
> +
> +
> + if (!ctx) {
> + const char *lenp;
> + char *endstr = NULL;
> + request_dir_conf *dconf = ap_get_module_config(f->r->per_dir_config,
> + &request_module);
> +
> + /* must we step out of the way? */
> + if (!dconf->keep_body || f->r->kept_body) {
> + ap_remove_input_filter(f);
> + return ap_get_brigade(f->next, b, mode, block, readbytes);
> + }
> +
> + f->ctx = ctx = apr_pcalloc(f->r->pool, sizeof(*ctx));
> +
> + /* fail fast if the content length exceeds keep body */
> + lenp = apr_table_get(f->r->headers_in, "Content-Length");
> + if (lenp) {
> +
> + /* Protects against over/underflow, non-digit chars in the
> + * string (excluding leading space) (the endstr checks)
> + * and a negative number. */
> + if (apr_strtoff(&ctx->remaining, lenp, &endstr, 10)
> + || endstr == lenp || *endstr || ctx->remaining < 0) {
> +
> + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, f->r,
> + "Invalid Content-Length");
> +
> + ap_remove_input_filter(f);
> + return bail_out_on_error(b, f, HTTP_REQUEST_ENTITY_TOO_LARGE);
> + }
> +
> + /* If we have a limit in effect and we know the C-L ahead of
> + * time, stop it here if it is invalid.
> + */
> + if (dconf->keep_body < ctx->remaining) {
> + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, f->r,
> + "Requested content-length of %" APR_OFF_T_FMT
> + " is larger than the configured limit"
> + " of %" APR_OFF_T_FMT, ctx->remaining, dconf->keep_body);
> + ap_remove_input_filter(f);
> + return bail_out_on_error(b, f, HTTP_REQUEST_ENTITY_TOO_LARGE);
> + }
> +
> + }
> +
> + f->r->kept_body = apr_brigade_create(f->r->pool, f->r->connection->bucket_alloc);
> + ctx->remaining = dconf->keep_body;
> +
> + }
> +
> + /* get the brigade from upstream, and read it in to get its length */
> + rv = ap_get_brigade(f->next, b, mode, block, readbytes);
> + if (rv == APR_SUCCESS) {
> + rv = apr_brigade_length(b, 1, &len);
> + }
> +
> + /* does the length take us over the limit? */
> + if (APR_SUCCESS == rv && len > ctx->remaining) {
> + if (f->r->kept_body) {
> + apr_brigade_cleanup(f->r->kept_body);
> + f->r->kept_body = NULL;
> + }
> + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, f->r,
> + "Requested content-length of %" APR_OFF_T_FMT
> + " is larger than the configured limit"
> + " of %" APR_OFF_T_FMT, len, ctx->keep_body);
> + return bail_out_on_error(b, f, HTTP_REQUEST_ENTITY_TOO_LARGE);
> + }
> + ctx->remaining -= len;
> +
> + /* pass any errors downstream */
> + if (rv != APR_SUCCESS) {
> + if (f->r->kept_body) {
> + apr_brigade_cleanup(f->r->kept_body);
> + f->r->kept_body = NULL;
> + }
> + return rv;
> + }
> +
> + /* all is well, set aside the buckets */
> + for (bucket = APR_BRIGADE_FIRST(b);
> + bucket != APR_BRIGADE_SENTINEL(b);
> + bucket = APR_BUCKET_NEXT(bucket))
> + {
> + apr_bucket_copy(bucket, &e);
What about transient buckets? Don't we need to set them aside?
> + APR_BRIGADE_INSERT_TAIL(f->r->kept_body, e);
> + }
> +
> + return APR_SUCCESS;
> +}
> +
> +
> +typedef struct kept_body_filter_ctx {
> + apr_off_t offset;
> + apr_off_t remaining;
> +} kept_body_ctx_t;
> +
> +/**
> + * Initialisation of filter to handle a kept body on subrequests.
> + *
> + * If a body is to be reinserted into a subrequest, any chunking will have
> + * been removed from the body during storage. We need to change the request
> + * from Transfer-Encoding: chunked to an explicit Content-Length.
> + */
> +static int kept_body_filter_init(ap_filter_t *f) {
> + apr_off_t length = 0;
> + request_rec *r = f->r;
> + apr_bucket_brigade *kept_body = r->kept_body;
> +
> + if (kept_body) {
> + apr_table_unset(r->headers_in, "Transfer-Encoding");
> + apr_brigade_length(kept_body, 1, &length);
> + apr_table_set(r->headers_in, "Content-Length", apr_off_t_toa(r->pool, length));
> + }
> +
> + return OK;
> +}
> +
> +/**
> + * Filter to handle a kept body on subrequests.
> + *
> + * If a body has been previously kept by the request, and if a subrequest wants
> + * to re-insert the body into the request, this input filter makes it happen.
> + */
> +AP_DECLARE(apr_status_t) ap_kept_body_filter(ap_filter_t *f, apr_bucket_brigade *b,
> + ap_input_mode_t mode, apr_read_type_e block,
> + apr_off_t readbytes) {
> + request_rec *r = f->r;
> + apr_bucket_brigade *kept_body = r->kept_body;
> + kept_body_ctx_t *ctx = f->ctx;
> + apr_bucket *ec, *e2;
> + apr_status_t rv;
> +
> + /* just get out of the way of things we don't want. */
> + if (!kept_body || (mode != AP_MODE_READBYTES && mode != AP_MODE_GETLINE)) {
> + return ap_get_brigade(f->next, b, mode, block, readbytes);
> + }
> +
> + /* set up the context if it does not already exist */
> + if (!ctx) {
> + f->ctx = ctx = apr_palloc(f->r->pool, sizeof(*ctx));
> + ctx->offset = 0;
> + apr_brigade_length(kept_body, 1, &ctx->remaining);
> + }
> +
> + /* kept_body is finished, send next filter */
> + if (ctx->remaining <= 0) {
> + return ap_get_brigade(f->next, b, mode, block, readbytes);
> + }
> +
> + /* send all of the kept_body, but no more */
> + if (readbytes > ctx->remaining) {
> + readbytes = ctx->remaining;
> + }
> +
> + /* send part of the kept_body */
> + if ((rv = apr_brigade_partition(kept_body, ctx->offset, &ec)) != APR_SUCCESS) {
> + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
> + "apr_brigade_partition() failed on kept_body at %" APR_OFF_T_FMT, ctx->offset);
> + return rv;
> + }
> + if ((rv = apr_brigade_partition(kept_body, ctx->offset + readbytes, &e2)) != APR_SUCCESS) {
> + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
> + "apr_brigade_partition() failed on kept_body at %" APR_OFF_T_FMT, ctx->offset + readbytes);
> + return rv;
> + }
> +
> + do {
> + apr_bucket *foo;
> + const char *str;
> + apr_size_t len;
> +
> + if (apr_bucket_copy(ec, &foo) != APR_SUCCESS) {
> + /* As above; this should not fail since the bucket has
> + * a known length, but just to be sure, this takes
> + * care of uncopyable buckets that do somehow manage
> + * to slip through. */
> + /* XXX: check for failure? */
> + apr_bucket_read(ec, &str, &len, APR_BLOCK_READ);
> + apr_bucket_copy(ec, &foo);
> + }
> + APR_BRIGADE_INSERT_TAIL(b, foo);
> + ec = APR_BUCKET_NEXT(ec);
> + } while (ec != e2);
> +
> + ctx->remaining -= readbytes;
> + ctx->offset += readbytes;
> + return APR_SUCCESS;
Why using ctx->offset at all and not just taking all data from the kept_body brigade until readbytes,
copy it over to b and remove it afterwards from the kept_body brigade. This would save one call
to apr_brigade_partition.
> +
> +}
> +
> +/* form parsing stuff */
> +typedef enum {
> + FORM_NORMAL,
> + FORM_AMP,
> + FORM_NAME,
> + FORM_VALUE,
> + FORM_PERCENTA,
> + FORM_PERCENTB,
> + FORM_ABORT
> +} ap_form_type_t;
> +
> +/**
> + * Read the body and parse any form found, which must be of the
> + * type application/x-www-form-urlencoded.
> + *
> + * Name/value pairs are returned in an array, with the names as
> + * strings with a maximum length of HUGE_STRING_LEN, and the
> + * values as bucket brigades. This allows values to be arbitrarily
> + * large.
> + *
> + * All url-encoding is removed from both the names and the values
> + * on the fly. The names are interpreted as strings, while the
> + * values are interpreted as blocks of binary data, that may
> + * contain the 0 character.
> + *
> + * In order to ensure that resource limits are not exceeded, a
> + * maximum size must be provided. If the sum of the lengths of
> + * the names and the values exceed this size, this function
> + * will return HTTP_REQUEST_ENTITY_TOO_LARGE.
> + *
> + * An optional number of parameters can be provided, if the number
> + * of parameters provided exceeds this amount, this function will
> + * return HTTP_REQUEST_ENTITY_TOO_LARGE. If this value is negative,
> + * no limit is imposed, and the number of parameters is in turn
> + * constrained by the size parameter above.
> + *
> + * This function honours any kept_body configuration, and the
> + * original raw request body will be saved to the kept_body brigade
> + * if so configured, just as ap_discard_request_body does.
> + *
> + * NOTE: File upload is not yet supported, but can be without change
> + * to the function call.
> + */
> +AP_DECLARE(int) ap_parse_request_form(request_rec * r, apr_array_header_t ** ptr,
> + apr_size_t num, apr_size_t size)
> +{
> + request_dir_conf *dconf;
> + apr_off_t left = 0;
> + apr_bucket_brigade *bb = NULL, *kept_body = NULL;
> + apr_bucket *e;
> + int seen_eos = 0;
> + char buffer[HUGE_STRING_LEN + 1];
> + const char *ct;
> + apr_size_t offset = 0;
> + ap_form_type_t state = FORM_NAME, percent = FORM_NORMAL;
> + ap_form_pair_t *pair = NULL;
> + apr_array_header_t *pairs = apr_array_make(r->pool, 4, sizeof(ap_form_pair_t));
> +
> + char hi = 0;
> + char low = 0;
> +
> + *ptr = pairs;
> +
> + /* sanity check - we only support forms for now */
> + ct = apr_table_get(r->headers_in, "Content-Type");
> + if (!ct || strcmp("application/x-www-form-urlencoded", ct)) {
> + return ap_discard_request_body(r);
> + }
> +
> + dconf = ap_get_module_config(r->per_dir_config,
> + &request_module);
> + if (dconf->keep_body > 0) {
> + left = dconf->keep_body;
> + kept_body = apr_brigade_create(r->pool, r->connection->bucket_alloc);
> + }
> +
> + bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
> + do {
> + apr_bucket *bucket = NULL, *last = NULL;
> +
> + int rv = ap_get_brigade(r->input_filters, bb, AP_MODE_READBYTES,
> + APR_BLOCK_READ, HUGE_STRING_LEN);
> + if (rv != APR_SUCCESS) {
> + apr_brigade_destroy(bb);
> + return (rv == AP_FILTER_ERROR) ? rv : HTTP_BAD_REQUEST;
> + }
> +
> + for (bucket = APR_BRIGADE_FIRST(bb);
> + bucket != APR_BRIGADE_SENTINEL(bb);
> + last = bucket, bucket = APR_BUCKET_NEXT(bucket)) {
> + const char *data;
> + apr_size_t len, slide;
> +
> + if (last) {
> + apr_bucket_delete(last);
> + }
> + if (APR_BUCKET_IS_EOS(bucket)) {
> + seen_eos = 1;
> + break;
> + }
> + if (bucket->length == 0) {
> + continue;
> + }
> +
> + rv = apr_bucket_read(bucket, &data, &len, APR_BLOCK_READ);
> + if (rv != APR_SUCCESS) {
> + apr_brigade_destroy(bb);
> + return HTTP_BAD_REQUEST;
> + }
> +
> + slide = len;
> + while (state != FORM_ABORT && slide-- > 0 && size >= 0 && num != 0) {
> + char c = *data++;
> + if ('+' == c) {
> + c = ' ';
> + }
> + else if ('&' == c) {
> + state = FORM_AMP;
> + }
> + if ('%' == c) {
> + percent = FORM_PERCENTA;
> + continue;
> + }
> + if (FORM_PERCENTA == percent) {
> + if (c >= 'a') {
> + hi = c - 'a' + 10;
> + }
> + else if (c >= 'A') {
> + hi = c - 'A' + 10;
> + }
> + else if (c >= '0') {
> + hi = c - '0';
> + }
> + hi = hi << 4;
> + percent = FORM_PERCENTB;
> + continue;
> + }
> + if (FORM_PERCENTB == percent) {
> + if (c >= 'a') {
> + low = c - 'a' + 10;
> + }
> + else if (c >= 'A') {
> + low = c - 'A' + 10;
> + }
> + else if (c >= '0') {
> + low = c - '0';
> + }
> + c = low ^ hi;
Shouldn't this be c = low + hi ?
> + percent = FORM_NORMAL;
> + }
> + switch (state) {
> + case FORM_AMP:
> + if (pair) {
> + const char *tmp = apr_pmemdup(r->pool, buffer, offset);
> + apr_bucket *b = apr_bucket_pool_create(tmp, offset, r->pool, r->connection->bucket_alloc);
> + APR_BRIGADE_INSERT_TAIL(pair->value, b);
> + }
> + state = FORM_NAME;
> + pair = NULL;
> + offset = 0;
> + num--;
> + break;
> + case FORM_NAME:
> + if (offset < HUGE_STRING_LEN) {
> + if ('=' == c) {
> + buffer[offset] = 0;
> + offset = 0;
> + pair = (ap_form_pair_t *) apr_array_push(pairs);
> + pair->name = apr_pstrdup(r->pool, buffer);
> + pair->value = apr_brigade_create(r->pool, r->connection->bucket_alloc);
> + state = FORM_VALUE;
> + }
> + else {
> + buffer[offset++] = c;
> + size--;
> + }
> + }
> + else {
> + state = FORM_ABORT;
> + }
> + break;
> + case FORM_VALUE:
> + if (offset >= HUGE_STRING_LEN) {
> + const char *tmp = apr_pmemdup(r->pool, buffer, offset);
> + apr_bucket *b = apr_bucket_pool_create(tmp, offset, r->pool, r->connection->bucket_alloc);
> + APR_BRIGADE_INSERT_TAIL(pair->value, b);
> + offset = 0;
> + }
> + buffer[offset++] = c;
> + size--;
> + break;
> + default:
> + break;
> + }
> + }
> +
> + /* If we have been asked to, keep the data up until the
> + * configured limit. If the limit is exceeded, we return an
> + * HTTP_REQUEST_ENTITY_TOO_LARGE response so the caller is
> + * clear the server couldn't handle their request.
> + */
> + if (kept_body) {
> + if (len <= left) {
> + apr_bucket_copy(bucket, &e);
> + APR_BRIGADE_INSERT_TAIL(kept_body, e);
> + left -= len;
> + }
> + else {
> + apr_brigade_destroy(bb);
> + apr_brigade_destroy(kept_body);
> + return HTTP_REQUEST_ENTITY_TOO_LARGE;
> + }
Why is this needed? Should this job be performed by the ap_keep_body_filter that should
be in our input filter chain if we want to keep the body?
Of course this depends when we call ap_parse_request_form. If we call it during the
authn/z phase the filter chain hasn't been setup. So maybe we should ensure that
this is the case.
> + }
> +
> + }
> +
> + apr_brigade_cleanup(bb);
> + } while (!seen_eos);
> +
> + if (FORM_ABORT == state || size < 0 || num == 0) {
> + return HTTP_REQUEST_ENTITY_TOO_LARGE;
> + }
> + else if (FORM_VALUE == state && pair && offset > 0) {
> + const char *tmp = apr_pmemdup(r->pool, buffer, offset);
> + apr_bucket *b = apr_bucket_pool_create(tmp, offset, r->pool, r->connection->bucket_alloc);
> + APR_BRIGADE_INSERT_TAIL(pair->value, b);
> + }
> +
> + if (kept_body) {
> + r->kept_body = kept_body;
> + }
> +
> + return OK;
> +
> +}
> +
> +/**
> + * Fixups hook.
> + *
> + * Add the KEEP_BODY filter to the request, if the admin wants to keep
> + * the body using the KeptBodySize directive.
> + *
> + * @param r The request
> + */
> +static int request_fixups(request_rec * r)
> +{
> + request_dir_conf *conf = ap_get_module_config(r->per_dir_config,
> + &request_module);
> +
> + if (conf->keep_body) {
> + ap_add_input_filter_handle(ap_keep_body_input_filter_handle,
> + NULL, r, r->connection);
> + }
> +
> + return OK;
Why not using the insert_filter hook?
> +
> +}
> +
> Modified: httpd/httpd/trunk/server/request.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/server/request.c?rev=647263&r1=647262&r2=647263&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/server/request.c (original)
> +++ httpd/httpd/trunk/server/request.c Fri Apr 11 11:41:53 2008
> @@ -45,6 +45,7 @@
> #include "util_charset.h"
> #include "util_script.h"
> #include "ap_expr.h"
> +#include "mod_request.h"
>
> #include "mod_core.h"
>
> @@ -1648,8 +1649,8 @@
> * Add the KEPT_BODY filter, which will insert any body marked to be
> * kept for the use of a subrequest, into the subrequest.
> */
> - ap_add_input_filter_handle(ap_kept_body_input_filter_handle,
> - NULL, rnew, rnew->connection);
> + ap_add_input_filter(KEPT_BODY_FILTER,
> + NULL, rnew, rnew->connection);
>
This creates an error message on each subrequest if mod_request is not loaded, because
in this case the KEPT_BODY_FILTER is not registered.
Regards
Rüdiger
|
smime.p7s
