ModSecurity/apache2/apache2_io.c at v2/exp/ModSecurity_for_Java · CodingWord/ModSecurity · GitHub

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* ModSecurity for Apache 2.x, http://www.modsecurity.org/

* 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

* If any of the files related to licensing are missing or if you have any

* other questions related to licensing please contact Trustwave Holdings, Inc.

* directly using the email address security@modsecurity.org.

#include <util_filter.h>

#include "modsecurity.h"

#include "apache2.h"

#include "msc_crypt.h"

/* -- Input filter -- */

#if 0

static void dummy_free_func(void *data) {}

#endif

/**

* This request filter will forward the previously stored

* request body further down the chain (most likely to the

* processing module).

apr_status_t input_filter(ap_filter_t *f, apr_bucket_brigade *bb_out,

ap_input_mode_t mode, apr_read_type_e block, apr_off_t nbytes)

{

modsec_rec *msr = (modsec_rec *)f->ctx;

msc_data_chunk *chunk = NULL;

apr_bucket *bucket;

apr_status_t rc;

char *my_error_msg = NULL;

if (msr == NULL) {

ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, f->r->server,

"ModSecurity: Internal error in input filter: msr is null.");

ap_remove_input_filter(f);

return APR_EGENERAL;

}

/* Make sure we are using the current request */

msr->r = f->r;

if (msr->phase < PHASE_REQUEST_BODY) {

msr_log(msr, 1, "Internal error: REQUEST_BODY phase incomplete for input filter in phase %d", msr->phase);

return APR_EGENERAL;

}

if ((msr->if_status == IF_STATUS_COMPLETE)||(msr->if_status == IF_STATUS_NONE)) {

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Input forwarding already complete, skipping (f %pp, r %pp).", f, f->r);

}

ap_remove_input_filter(f);

return ap_get_brigade(f->next, bb_out, mode, block, nbytes);

}

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Forwarding input: mode=%d, block=%d, nbytes=%" APR_OFF_T_FMT

" (f %pp, r %pp).", mode, block, nbytes, f, f->r);

}

if (msr->if_started_forwarding == 0) {

msr->if_started_forwarding = 1;

rc = modsecurity_request_body_retrieve_start(msr, &my_error_msg);

if (rc == -1) {

if (my_error_msg != NULL) {

msr_log(msr, 1, "%s", my_error_msg);

}

return APR_EGENERAL;

}

rc = modsecurity_request_body_retrieve(msr, &chunk, (unsigned int)nbytes, &my_error_msg);

if (rc == -1) {

if (my_error_msg != NULL) {

msr_log(msr, 1, "%s", my_error_msg);

}

return APR_EGENERAL;

}

if (chunk && (!msr->txcfg->stream_inbody_inspection || (msr->txcfg->stream_inbody_inspection && msr->if_stream_changed == 0))) {

/* Copy the data we received in the chunk */

bucket = apr_bucket_heap_create(chunk->data, chunk->length, NULL,

f->r->connection->bucket_alloc);

#if 0

It would seem that we cannot prevent other filters in the chain

from modifying data in-place. Hence we copy.

if (chunk->is_permanent) {

/* Do not make a copy of the data we received in the chunk. */

bucket = apr_bucket_heap_create(chunk->data, chunk->length, dummy_free_func,

f->r->connection->bucket_alloc);

} else {

/* Copy the data we received in the chunk. */

bucket = apr_bucket_heap_create(chunk->data, chunk->length, NULL,

f->r->connection->bucket_alloc);

}

#endif

if (bucket == NULL) return APR_EGENERAL;

APR_BRIGADE_INSERT_TAIL(bb_out, bucket);

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Forwarded %" APR_SIZE_T_FMT " bytes.", chunk->length);

}

} else if (msr->stream_input_data != NULL) {

msr->if_stream_changed = 0;

bucket = apr_bucket_heap_create(msr->stream_input_data, msr->stream_input_length, NULL,

f->r->connection->bucket_alloc);

if (msr->txcfg->stream_inbody_inspection) {

if(msr->stream_input_data != NULL) {

free(msr->stream_input_data);

msr->stream_input_data = NULL;

}

if (bucket == NULL) return APR_EGENERAL;

APR_BRIGADE_INSERT_TAIL(bb_out, bucket);

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input stream filter: Forwarded %" APR_SIZE_T_FMT " bytes.", msr->stream_input_length);

}

if (rc == 0) {

modsecurity_request_body_retrieve_end(msr);

if (msr->if_seen_eos) {

bucket = apr_bucket_eos_create(f->r->connection->bucket_alloc);

if (bucket == NULL) return APR_EGENERAL;

APR_BRIGADE_INSERT_TAIL(bb_out, bucket);

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Sent EOS.");

}

/* We're done */

msr->if_status = IF_STATUS_COMPLETE;

ap_remove_input_filter(f);

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Input forwarding complete.");

}

return APR_SUCCESS;

}

/**

* Reads request body from a client.

apr_status_t read_request_body(modsec_rec *msr, char **error_msg) {

request_rec *r = msr->r;

unsigned int finished_reading;

apr_bucket_brigade *bb_in;

apr_bucket *bucket;

if (error_msg == NULL) return -1;

*error_msg = NULL;

if (msr->reqbody_should_exist != 1) {

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: This request does not have a body.");

}

return 0;

}

if (msr->txcfg->reqbody_access != 1) {

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Request body access not enabled.");

}

return 0;

}

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Reading request body.");

}

if (modsecurity_request_body_start(msr, error_msg) < 0) {

return -1;

}

finished_reading = 0;

msr->if_seen_eos = 0;

bb_in = apr_brigade_create(msr->mp, r->connection->bucket_alloc);

if (bb_in == NULL) return -1;

do {

apr_status_t rc;

rc = ap_get_brigade(r->input_filters, bb_in, AP_MODE_READBYTES, APR_BLOCK_READ, HUGE_STRING_LEN);

if (rc != APR_SUCCESS) {

/* NOTE Apache returns AP_FILTER_ERROR here when the request is

* too large and APR_EGENERAL when the client disconnects.

switch(rc) {

case APR_EOF :

*error_msg = apr_psprintf(msr->mp, "Error reading request body: %s", get_apr_error(msr->mp, rc));

return -6;

case APR_TIMEUP :

*error_msg = apr_psprintf(msr->mp, "Error reading request body: %s", get_apr_error(msr->mp, rc));

return -4;

case AP_FILTER_ERROR :

*error_msg = apr_psprintf(msr->mp, "Error reading request body: HTTP Error 413 - Request entity too large. (Most likely.)");

return -3;

case APR_EGENERAL :

*error_msg = apr_psprintf(msr->mp, "Error reading request body: Client went away.");

return -2;

default :

*error_msg = apr_psprintf(msr->mp, "Error reading request body: %s", get_apr_error(msr->mp, rc));

return -1;

}

/* Loop through the buckets in the brigade in order

* to extract the size of the data available.

for(bucket = APR_BRIGADE_FIRST(bb_in);

bucket != APR_BRIGADE_SENTINEL(bb_in);

bucket = APR_BUCKET_NEXT(bucket))

{

const char *buf;

apr_size_t buflen;

rc = apr_bucket_read(bucket, &buf, &buflen, APR_BLOCK_READ);

if (rc != APR_SUCCESS) {

*error_msg = apr_psprintf(msr->mp, "Failed reading input / bucket (%d): %s", rc, get_apr_error(msr->mp, rc));

return -1;

}

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Input filter: Bucket type %s contains %" APR_SIZE_T_FMT " bytes.",

bucket->type->name, buflen);

}

/* Check request body limit (should only trigger on chunked requests). */

if (msr->reqbody_length + buflen > (apr_size_t)msr->txcfg->reqbody_limit) {

if((msr->txcfg->is_enabled == MODSEC_ENABLED) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_REJECT)) {

*error_msg = apr_psprintf(msr->mp, "Request body is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_limit);

return -5;

} else if((msr->txcfg->is_enabled == MODSEC_ENABLED) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_PARTIAL)) {

*error_msg = apr_psprintf(msr->mp, "Request body is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_limit);

} else if ((msr->txcfg->is_enabled == MODSEC_DETECTION_ONLY) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_PARTIAL)){

*error_msg = apr_psprintf(msr->mp, "Request body is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_limit);

} else if ((msr->txcfg->is_enabled == MODSEC_DETECTION_ONLY) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_REJECT)){

*error_msg = apr_psprintf(msr->mp, "Request body is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_limit);

} else {

*error_msg = apr_psprintf(msr->mp, "Request body is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_limit);

return -5;

}

if (msr->txcfg->stream_inbody_inspection == 1) {

msr->stream_input_length+=buflen;

modsecurity_request_body_to_stream(msr, buf, buflen, error_msg);

}

msr->reqbody_length += buflen;

if (buflen != 0) {

int rcbs = modsecurity_request_body_store(msr, buf, buflen, error_msg);

if (msr->reqbody_length > (apr_size_t)msr->txcfg->reqbody_limit && msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_PARTIAL) {

finished_reading = 1;

}

if (rcbs < 0) {

if (rcbs == -5) {

if((msr->txcfg->is_enabled == MODSEC_ENABLED) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_REJECT)) {

*error_msg = apr_psprintf(msr->mp, "Request body no files data length is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_no_files_limit);

return -5;

} else if ((msr->txcfg->is_enabled == MODSEC_ENABLED) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_PARTIAL)) {

*error_msg = apr_psprintf(msr->mp, "Request body no files data length is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_no_files_limit);

} else if ((msr->txcfg->is_enabled == MODSEC_DETECTION_ONLY) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_PARTIAL)) {

*error_msg = apr_psprintf(msr->mp, "Request body no files data length is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_no_files_limit);

} else {

*error_msg = apr_psprintf(msr->mp, "Request body no files data length is larger than the "

"configured limit (%ld).", msr->txcfg->reqbody_no_files_limit);

return -5;

}

if((msr->txcfg->is_enabled == MODSEC_ENABLED) && (msr->txcfg->if_limit_action == REQUEST_BODY_LIMIT_ACTION_REJECT))

return -1;

}

if (APR_BUCKET_IS_EOS(bucket)) {

finished_reading = 1;

msr->if_seen_eos = 1;

}

apr_brigade_cleanup(bb_in);

} while(!finished_reading);

// TODO: Why ignore the return code here?

modsecurity_request_body_end(msr, error_msg);

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Input filter: Completed receiving request body (length %" APR_SIZE_T_FMT ").",

msr->reqbody_length);

}

msr->if_status = IF_STATUS_WANTS_TO_RUN;

return 1;

}

/* -- Output filter -- */

/**

* Examines the configuration and the response MIME type

* in order to determine whether output buffering should

* run or not.

static int output_filter_should_run(modsec_rec *msr, request_rec *r) {

char *content_type = NULL;

/* Check configuration. */

if (msr->txcfg->resbody_access != 1) {

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Output filter: Response body buffering is not enabled.");

}

return 0;

}

/* Check MIME type. */

if ((msr->txcfg->of_mime_types == NULL)||(msr->txcfg->of_mime_types == NOT_SET_P)) {

msr_log(msr, 1, "Output filter: MIME type structures corrupted (internal error).");

return -1;

}

if (r->content_type != NULL) {

char *p = NULL;

content_type = apr_pstrdup(msr->mp, r->content_type);

if (content_type == NULL) {

msr_log(msr, 1, "Output filter: Failed to allocate memory for content type.");

return -1;

}

/* Hide the character encoding information

* if present. Sometimes the content type header

* looks like this "text/html; charset=xyz" ...

p = strstr(content_type, ";");

if (p != NULL) {

*p = '\0';

}

strtolower_inplace((unsigned char *)content_type);

if (strcmp(content_type, "text/html") == 0) {

/* Useful information to have should we later

* decide to do something with the HTML output.

msr->resbody_contains_html = 1;

}

} else {

content_type = "null";

}

if (apr_table_get(msr->txcfg->of_mime_types, content_type) != NULL) return 1;

msr_log(msr, 4, "Output filter: Not buffering response body for unconfigured MIME type \"%s\".", content_type);

return 0;

}

/**

* Initialises the output filter.

static apr_status_t output_filter_init(modsec_rec *msr, ap_filter_t *f,

apr_bucket_brigade *bb_in)

{

request_rec *r = f->r;

const char *s_content_length = NULL;

apr_status_t rc;

msr->of_brigade = apr_brigade_create(msr->mp, f->c->bucket_alloc);

if (msr->of_brigade == NULL) {

msr_log(msr, 1, "Output filter: Failed to create brigade.");

return -1;

}

msr->of_status = OF_STATUS_IN_PROGRESS;

rc = output_filter_should_run(msr, r);

if (rc < 0) return -1; /* output_filter_should_run() generates error msg */

if (rc == 0) return 0;

/* Do not check the output limit if we are willing to

* process partial response bodies.

if (msr->txcfg->of_limit_action == RESPONSE_BODY_LIMIT_ACTION_PARTIAL) {

return 1;

}

/* Look up the Content-Length header to see if we know

* the amount of data coming our way. If we do and if

* it's too much we might want to stop processing right here.

s_content_length = apr_table_get(r->headers_out, "Content-Length");

if (s_content_length == NULL) {

/* Try this too, mod_cgi seems to put headers there. */

s_content_length = apr_table_get(r->err_headers_out, "Content-Length");

}

if (s_content_length != NULL) {

long int len;

len = strtol(s_content_length, NULL, 10);

if ((len == LONG_MIN)||(len == LONG_MAX)||(len < 0)||(len >= 1073741824)) {

msr_log(msr, 1, "Output filter: Invalid Content-Length: %s", log_escape_nq(r->pool,

(char *)s_content_length));

return -1; /* Invalid. */

}

if (len == 0) {

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Output filter: Skipping response since Content-Length is zero.");

}

return 0;

}

if (len > msr->txcfg->of_limit) {

msr_log(msr, 1, "Output filter: Content-Length (%s) over the limit (%ld).",

log_escape_nq(r->pool, (char *)s_content_length), msr->txcfg->of_limit);

msr->outbound_error = 1;

return -2; /* Over the limit. */

}

return 1;

}

/**

* Send the accumulated content down the filter stream

* and to the client.

static apr_status_t send_of_brigade(modsec_rec *msr, ap_filter_t *f) {

apr_status_t rc;

rc = ap_pass_brigade(f->next, msr->of_brigade);

if (rc != APR_SUCCESS) {

/* TODO: These need to move to flags in 2.6. For now log them

* at level 4 so that they are not confusing users.

int log_level = 4;

if (msr->txcfg->debuglog_level >= log_level) {

switch(rc) {

case AP_NOBODY_WROTE :

msr_log(msr, log_level, "Output filter: Error while forwarding response data (%d): No data", rc);

break;

case AP_FILTER_ERROR :

/* Look like this is caused by the error

* already being handled, so we should ignore it

msr_log(msr, log_level, "Output filter: Error while forwarding response data (%d): Filter error", rc);

break;

default :

msr_log(msr, log_level, "Output filter: Error while forwarding response data (%d): %s",

rc, get_apr_error(msr->mp, rc));

break;

}

return rc;

}

return APR_SUCCESS;

}

/** \brief Inject data into brigade

* \param msr ModSecurity transation resource

* \param ap_filter_t Apache filter

static void inject_content_to_of_brigade(modsec_rec *msr, ap_filter_t *f) {

apr_bucket *b;

if (msr->txcfg->content_injection_enabled && msr->stream_output_data != NULL) {

apr_bucket *bucket_ci = NULL;

bucket_ci = apr_bucket_heap_create(msr->stream_output_data,

msr->stream_output_length, NULL, f->r->connection->bucket_alloc);

for (b = APR_BRIGADE_FIRST(msr->of_brigade); b != APR_BRIGADE_SENTINEL(msr->of_brigade); b = APR_BUCKET_NEXT(b)) {

if(!APR_BUCKET_IS_METADATA(b))

apr_bucket_delete(b);

}

APR_BRIGADE_INSERT_HEAD(msr->of_brigade, bucket_ci);

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content Injection: Data reinjected bytes [%"APR_SIZE_T_FMT"]",msr->stream_output_length);

}

/**

static void prepend_content_to_of_brigade(modsec_rec *msr, ap_filter_t *f) {

if ((msr->txcfg->content_injection_enabled) && (msr->content_prepend) && (!msr->of_skipping)) {

apr_bucket *bucket_ci = NULL;

bucket_ci = apr_bucket_heap_create(msr->content_prepend,

msr->content_prepend_len, NULL, f->r->connection->bucket_alloc);

APR_BRIGADE_INSERT_HEAD(msr->of_brigade, bucket_ci);

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content Injection (b): Added content to top: %s",

log_escape_nq_ex(msr->mp, msr->content_prepend, msr->content_prepend_len));

}

/**

static int flatten_response_body(modsec_rec *msr) {

apr_status_t rc;

msr->resbody_status = RESBODY_STATUS_READ_BRIGADE;

if (msr->resbody_length + 1 <= 0) {

msr_log(msr, 1, "Output filter: Invalid response length: %" APR_SIZE_T_FMT, msr->resbody_length);

return -1;

}

msr->resbody_data = apr_palloc(msr->mp, msr->resbody_length + 1);

if (msr->resbody_data == NULL) {

msr_log(msr, 1, "Output filter: Response body data memory allocation failed. Asked for: %" APR_SIZE_T_FMT,

msr->resbody_length + 1);

return -1;

}

rc = apr_brigade_flatten(msr->of_brigade, msr->resbody_data, &msr->resbody_length);

if (rc != APR_SUCCESS) {

msr_log(msr, 1, "Output filter: Failed to flatten brigade (%d): %s", rc,

get_apr_error(msr->mp, rc));

return -1;

}

msr->resbody_data[msr->resbody_length] = '\0';

msr->resbody_status = RESBODY_STATUS_READ;

if (msr->txcfg->stream_outbody_inspection && msr->txcfg->hash_is_enabled == HASH_DISABLED) {

msr->stream_output_length = msr->resbody_length;

if (msr->stream_output_data == NULL) {

msr_log(msr, 1, "Output filter: Stream Response body data memory allocation failed. Asked for: %" APR_SIZE_T_FMT,

msr->stream_output_length + 1);

return -1;

}

memset(msr->stream_output_data, 0, msr->stream_output_length+1);

memcpy(msr->stream_output_data, msr->resbody_data, msr->stream_output_length);

msr->stream_output_data[msr->stream_output_length] = '\0';

} else if (msr->txcfg->stream_outbody_inspection && msr->txcfg->hash_is_enabled == HASH_ENABLED) {

int retval = 0;

apr_time_t time1 = apr_time_now();

retval = init_response_body_html_parser(msr);

if(retval == 1) {

retval = hash_response_body_links(msr);

if(retval > 0) {

retval = inject_hashed_response_body(msr, retval);

if(retval < 0){

msr_log(msr, 1, "inject_hashed_response_body: Unable to inject hash into response body. Returning response without changes." );

}else{

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Hash completed in %" APR_TIME_T_FMT " usec.", (apr_time_now() - time1));

}

if(msr->of_stream_changed == 0) {

msr->stream_output_length = msr->resbody_length;

if (msr->stream_output_data == NULL) {

msr_log(msr, 1, "Output filter: Stream Response body data memory allocation failed. Asked for: %" APR_SIZE_T_FMT,

msr->stream_output_length + 1);

return -1;

}

memset(msr->stream_output_data, 0, msr->stream_output_length+1);

memcpy(msr->stream_output_data, msr->resbody_data, msr->stream_output_length);

msr->stream_output_data[msr->stream_output_length] = '\0';

}

return 1;

}

/**

* Output filter.

apr_status_t output_filter(ap_filter_t *f, apr_bucket_brigade *bb_in) {

request_rec *r = f->r;

modsec_rec *msr = (modsec_rec *)f->ctx;

apr_bucket *bucket = NULL, *eos_bucket = NULL;

apr_status_t rc;

int start_skipping = 0;

/* Do we have the context? */

if (msr == NULL) {

ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, f->r->server,

"ModSecurity: Internal Error: msr is null in output filter.");

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

msr->r = r;

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Output filter: Receiving output (f %pp, r %pp).", f, f->r);

}

/* Put back the Accept-Encoding and TE request headers

* if they were removed from the request.

if (msr->txcfg->disable_backend_compression) {

char *ae = (char *)apr_table_get(msr->request_headers, "Accept-Encoding");

char *te = (char *)apr_table_get(msr->request_headers, "TE");

if ((ae != NULL)&&(apr_table_get(f->r->headers_in, "Accept-Encoding") == NULL)) {

apr_table_add(f->r->headers_in, "Accept-Encoding", ae);

}

if ((te != NULL)&&(apr_table_get(f->r->headers_in, "TE") == NULL)) {

apr_table_add(f->r->headers_in, "TE", te);

}

/* Initialise on first invocation */

if (msr->of_status == OF_STATUS_NOT_STARTED) {

/* Update our context from the request structure. */

msr->r = r;

msr->response_status = r->status;

msr->status_line = ((r->status_line != NULL)

? r->status_line : ap_get_status_line(r->status));

msr->response_protocol = get_response_protocol(r);

if(msr->txcfg->crypto_hash_location_rx == 1 || msr->txcfg->crypto_hash_location_pm == 1)

rc = modify_response_header(msr);

msr->response_headers = apr_table_overlay(msr->mp, r->err_headers_out, r->headers_out);

/* Process phase RESPONSE_HEADERS */

rc = modsecurity_process_phase(msr, PHASE_RESPONSE_HEADERS);

if (rc < 0) { /* error */

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

if (rc > 0) { /* transaction needs to be interrupted */

int status = perform_interception(msr);

if (status != DECLINED) { /* DECLINED means we allow-ed the request. */

ap_remove_output_filter(f);

msr->of_status = OF_STATUS_COMPLETE;

msr->resbody_status = RESBODY_STATUS_ERROR;

return send_error_bucket(msr, f, status);

}

msr->outbound_error = 0;

/* Decide whether to observe the response body. */

rc = output_filter_init(msr, f, bb_in);

switch(rc) {

case -2 : /* response too large */

case -1 : /* error */

/* there's something wrong with this response */

ap_remove_output_filter(f);

msr->of_status = OF_STATUS_COMPLETE;

msr->resbody_status = RESBODY_STATUS_ERROR;

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

case 0 :

/* We do not want to observe this response body

* but we need to remain attached to observe

* when it is completed so that we can run

* the RESPONSE_BODY phase.

msr->of_skipping = 1;

msr->resbody_status = RESBODY_STATUS_NOT_READ;

break;

default :

/* Continue (observe the response body). */

break;

}

/* If injecting content unset headers now. */

if (msr->txcfg->content_injection_enabled == 0) {

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content Injection: Not enabled.");

}

} else {

if ((msr->content_prepend) || (msr->content_append)) {

apr_table_unset(msr->r->headers_out, "Content-Length");

apr_table_unset(msr->r->headers_out, "Last-Modified");

apr_table_unset(msr->r->headers_out, "ETag");

apr_table_unset(msr->r->headers_out, "Expires");

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content Injection: Removing headers (C-L, L-M, Etag, Expires).");

}

} else {

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content Injection: Nothing to inject.");

}

/* Content injection (prepend & non-buffering). */

if ((msr->txcfg->content_injection_enabled) && (msr->content_prepend) && (msr->of_skipping)) {

apr_bucket *bucket_ci = apr_bucket_heap_create(msr->content_prepend,

msr->content_prepend_len, NULL, f->r->connection->bucket_alloc);

APR_BRIGADE_INSERT_HEAD(bb_in, bucket_ci);

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content Injection (nb): Added content to top: %s",

log_escape_nq_ex(msr->mp, msr->content_prepend, msr->content_prepend_len));

}

} else

if (msr->of_status == OF_STATUS_COMPLETE) {

msr_log(msr, 1, "Output filter: Internal error: output filtering complete yet filter was invoked.");

ap_remove_output_filter(f);

return APR_EGENERAL;

}

/* Loop through the buckets in the brigade in order

* to extract the size of the data available.

for(bucket = APR_BRIGADE_FIRST(bb_in);

bucket != APR_BRIGADE_SENTINEL(bb_in);

bucket = APR_BUCKET_NEXT(bucket)) {

const char *buf;

apr_size_t buflen;

/* Look into response data if configured to do so,

* unless we've already processed a partial response.

if ((msr->of_skipping == 0)&&(!msr->of_partial)) { /* Observe the response data. */

/* Retrieve data from the bucket. */

rc = apr_bucket_read(bucket, &buf, &buflen, APR_BLOCK_READ);

if (rc != APR_SUCCESS) {

msr->of_status = OF_STATUS_COMPLETE;

msr->resbody_status = RESBODY_STATUS_ERROR;

msr_log(msr, 1, "Output filter: Failed to read bucket (rc %d): %s",

rc, get_apr_error(r->pool, rc));

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Output filter: Bucket type %s contains %" APR_SIZE_T_FMT " bytes.",

bucket->type->name, buflen);

}

/* Check the response size. */

if (msr->resbody_length > (apr_size_t)msr->txcfg->of_limit) {

/* The size of the response is larger than what we're

* ready to accept. We need to decide what we want to do

* about it.

msr->outbound_error = 1;

if (msr->txcfg->of_limit_action == RESPONSE_BODY_LIMIT_ACTION_REJECT) {

/* Reject response. */

msr_log(msr, 1, "Output filter: Response body too large (over limit of %ld, "

"total not specified).", msr->txcfg->of_limit);

msr->of_status = OF_STATUS_COMPLETE;

msr->resbody_status = RESBODY_STATUS_PARTIAL;

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

} else {

/* Process partial response. */

start_skipping = 1;

msr->resbody_length = msr->txcfg->of_limit;

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Output filter: Processing partial response body (limit %ld)",

msr->txcfg->of_limit);

}

} else {

msr->resbody_length += buflen;

}

/* Have we reached the end of the response? */

if (APR_BUCKET_IS_EOS(bucket)) {

eos_bucket = bucket;

/* Inject content (append & non-buffering). */

if ((msr->txcfg->content_injection_enabled) && (msr->content_append)

&& (msr->of_skipping || msr->of_partial || start_skipping))

{

apr_bucket *bucket_ci = NULL;

bucket_ci = apr_bucket_heap_create(msr->content_append,

msr->content_append_len, NULL, f->r->connection->bucket_alloc);

APR_BUCKET_INSERT_BEFORE(bucket, bucket_ci);

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Content-Injection (nb): Added content to bottom: %s",

log_escape_nq_ex(msr->mp, msr->content_append, msr->content_append_len));

}

msr->of_done_reading = 1;

}

/* Add buckets in this brigade to the brigade

* we have in the context, but only if we actually

* want to keep the response body.

if ((msr->of_skipping == 0)&&(msr->of_partial == 0)) {

ap_save_brigade(f, &msr->of_brigade, &bb_in, msr->mp);

/* Do we need to process a partial response? */

if (start_skipping) {

if (msr->txcfg->stream_outbody_inspection) {

if(msr->stream_output_data != NULL) {

free(msr->stream_output_data);

msr->stream_output_data = NULL;

}

msr->stream_output_data = (char *)malloc(msr->resbody_length+1);

}

if (flatten_response_body(msr) < 0) {

if (msr->txcfg->stream_outbody_inspection) {

if(msr->stream_output_data != NULL) {

free(msr->stream_output_data);

msr->stream_output_data = NULL;

}

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

/* Process phase RESPONSE_BODY */

rc = modsecurity_process_phase(msr, PHASE_RESPONSE_BODY);

if (rc < 0) {

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

if (rc > 0) {

int status = perform_interception(msr);

if (status != DECLINED) { /* DECLINED means we allow-ed the request. */

ap_remove_output_filter(f);

return send_error_bucket(msr, f, status);

}

/* Prepend content as necessary. */

prepend_content_to_of_brigade(msr, f);

if ((rc = send_of_brigade(msr, f)) != APR_SUCCESS) {

return rc;

}

msr->of_partial = 1;

}

if (msr->of_done_reading == 0) {

/* We are done for now. We will be called again with more data. */

return APR_SUCCESS;

}

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Output filter: Completed receiving response body (buffered %s - %" APR_SIZE_T_FMT " bytes).",

(msr->of_partial ? "partial" : "full"), msr->resbody_length);

}

} else { /* Not looking at response data. */

if (msr->of_done_reading == 0) {

if (msr->txcfg->debuglog_level >= 9) {

msr_log(msr, 9, "Output filter: Sending input brigade directly.");

}

return ap_pass_brigade(f->next, bb_in);

}

if (msr->txcfg->debuglog_level >= 4) {

msr_log(msr, 4, "Output filter: Completed receiving response body (non-buffering).");

}

/* We've done our thing; remove us from the filter list. */

msr->of_status = OF_STATUS_COMPLETE;

ap_remove_output_filter(f);

/* Process phase RESPONSE_BODY, but

* only if it hasn't been processed already.

if (msr->phase < PHASE_RESPONSE_BODY) {

if (msr->txcfg->stream_outbody_inspection) {

if(msr->stream_output_data != NULL) {

free(msr->stream_output_data);

msr->stream_output_data = NULL;

}

msr->stream_output_data = (char *)malloc(msr->resbody_length+1);

}

if (flatten_response_body(msr) < 0) {

if (msr->txcfg->stream_outbody_inspection) {

if(msr->stream_output_data != NULL) {

free(msr->stream_output_data);

msr->stream_output_data = NULL;

}

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

rc = modsecurity_process_phase(msr, PHASE_RESPONSE_BODY);

if (rc < 0) {

ap_remove_output_filter(f);

return send_error_bucket(msr, f, HTTP_INTERNAL_SERVER_ERROR);

}

if (rc > 0) {

int status = perform_interception(msr);

if (status != DECLINED) { /* DECLINED means we allow-ed the request. */

ap_remove_output_filter(f);

return send_error_bucket(msr, f, status);

}

/* Now send data down the filter stream

* (full-buffering only).

if ((msr->of_skipping == 0)&&(!msr->of_partial)) {

if(msr->of_stream_changed == 1) {

inject_content_to_of_brigade(msr,f);

msr->of_stream_changed = 0;

}

if (msr->txcfg->stream_outbody_inspection) {

if(msr->stream_output_data != NULL) {

free(msr->stream_output_data);

msr->stream_output_data = NULL;

}

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