diff options
Diffstat (limited to 'modules/filters/mod_charset_lite.c')
| -rw-r--r-- | modules/filters/mod_charset_lite.c | 1142 |
1 files changed, 1142 insertions, 0 deletions
diff --git a/modules/filters/mod_charset_lite.c b/modules/filters/mod_charset_lite.c new file mode 100644 index 0000000..e3d1ce9 --- /dev/null +++ b/modules/filters/mod_charset_lite.c @@ -0,0 +1,1142 @@ +/* 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. + */ + +/* + * simple hokey charset recoding configuration module + * + * See mod_ebcdic and mod_charset for more thought-out examples. This + * one is just so Jeff can learn how a module works and experiment with + * basic character set recoding configuration. + * + * !!!This is an extremely cheap ripoff of mod_charset.c from Russian Apache!!! + */ + +#include "httpd.h" +#include "http_config.h" + +#include "http_core.h" +#include "http_log.h" +#include "http_main.h" +#include "http_protocol.h" +#include "http_request.h" +#include "util_charset.h" +#include "apr_buckets.h" +#include "util_filter.h" +#include "apr_strings.h" +#include "apr_lib.h" +#include "apr_xlate.h" +#define APR_WANT_STRFUNC +#include "apr_want.h" + +#define OUTPUT_XLATE_BUF_SIZE (16*1024) /* size of translation buffer used on output */ +#define INPUT_XLATE_BUF_SIZE (8*1024) /* size of translation buffer used on input */ + +#define XLATE_MIN_BUFF_LEFT 128 /* flush once there is no more than this much + * space left in the translation buffer + */ + +#define FATTEST_CHAR 8 /* we don't handle chars wider than this that straddle + * two buckets + */ + +/* extended error status codes; this is used in addition to an apr_status_t to + * track errors in the translation filter + */ +typedef enum { + EES_INIT = 0, /* no error info yet; value must be 0 for easy init */ + EES_LIMIT, /* built-in restriction encountered */ + EES_INCOMPLETE_CHAR, /* incomplete multi-byte char at end of content */ + EES_BUCKET_READ, + EES_DOWNSTREAM, /* something bad happened in a filter below xlate */ + EES_BAD_INPUT /* input data invalid */ +} ees_t; + +/* registered name of the output translation filter */ +#define XLATEOUT_FILTER_NAME "XLATEOUT" +/* registered name of input translation filter */ +#define XLATEIN_FILTER_NAME "XLATEIN" + +typedef struct charset_dir_t { + const char *charset_source; /* source encoding */ + const char *charset_default; /* how to ship on wire */ + /** module does ap_add_*_filter()? */ + enum {IA_INIT, IA_IMPADD, IA_NOIMPADD} implicit_add; + /** treat all mimetypes as text? */ + enum {FX_INIT, FX_FORCE, FX_NOFORCE} force_xlate; +} charset_dir_t; + +/* charset_filter_ctx_t is created for each filter instance; because the same + * filter code is used for translating in both directions, we need this context + * data to tell the filter which translation handle to use; it also can hold a + * character which was split between buckets + */ +typedef struct charset_filter_ctx_t { + apr_xlate_t *xlate; + int is_sb; /* single-byte translation? */ + charset_dir_t *dc; + ees_t ees; /* extended error status */ + apr_size_t saved; + char buf[FATTEST_CHAR]; /* we want to be able to build a complete char here */ + int ran; /* has filter instance run before? */ + int noop; /* should we pass brigades through unchanged? */ + char *tmp; /* buffer for input filtering */ + apr_bucket_brigade *bb; /* input buckets we couldn't finish translating */ + apr_bucket_brigade *tmpbb; /* used for passing downstream */ +} charset_filter_ctx_t; + +/* charset_req_t is available via r->request_config if any translation is + * being performed + */ +typedef struct charset_req_t { + charset_dir_t *dc; + charset_filter_ctx_t *output_ctx, *input_ctx; +} charset_req_t; + +module AP_MODULE_DECLARE_DATA charset_lite_module; + +static void *create_charset_dir_conf(apr_pool_t *p,char *dummy) +{ + charset_dir_t *dc = (charset_dir_t *)apr_pcalloc(p,sizeof(charset_dir_t)); + + return dc; +} + +static void *merge_charset_dir_conf(apr_pool_t *p, void *basev, void *overridesv) +{ + charset_dir_t *a = (charset_dir_t *)apr_pcalloc (p, sizeof(charset_dir_t)); + charset_dir_t *base = (charset_dir_t *)basev, + *over = (charset_dir_t *)overridesv; + + /* If it is defined in the current container, use it. Otherwise, use the one + * from the enclosing container. + */ + + a->charset_default = + over->charset_default ? over->charset_default : base->charset_default; + a->charset_source = + over->charset_source ? over->charset_source : base->charset_source; + a->implicit_add = + over->implicit_add != IA_INIT ? over->implicit_add : base->implicit_add; + a->force_xlate= + over->force_xlate != FX_INIT ? over->force_xlate : base->force_xlate; + return a; +} + +/* CharsetSourceEnc charset + */ +static const char *add_charset_source(cmd_parms *cmd, void *in_dc, + const char *name) +{ + charset_dir_t *dc = in_dc; + + dc->charset_source = name; + return NULL; +} + +/* CharsetDefault charset + */ +static const char *add_charset_default(cmd_parms *cmd, void *in_dc, + const char *name) +{ + charset_dir_t *dc = in_dc; + + dc->charset_default = name; + return NULL; +} + +/* CharsetOptions optionflag... + */ +static const char *add_charset_options(cmd_parms *cmd, void *in_dc, + const char *flag) +{ + charset_dir_t *dc = in_dc; + + if (!strcasecmp(flag, "ImplicitAdd")) { + dc->implicit_add = IA_IMPADD; + } + else if (!strcasecmp(flag, "NoImplicitAdd")) { + dc->implicit_add = IA_NOIMPADD; + } + else if (!strcasecmp(flag, "TranslateAllMimeTypes")) { + dc->force_xlate = FX_FORCE; + } + else if (!strcasecmp(flag, "NoTranslateAllMimeTypes")) { + dc->force_xlate = FX_NOFORCE; + } + else { + return apr_pstrcat(cmd->temp_pool, + "Invalid CharsetOptions option: ", + flag, + NULL); + } + + return NULL; +} + +/* find_code_page() is a fixup hook that checks if the module is + * configured and the input or output potentially need to be translated. + * If so, context is initialized for the filters. + */ +static int find_code_page(request_rec *r) +{ + charset_dir_t *dc = ap_get_module_config(r->per_dir_config, + &charset_lite_module); + charset_req_t *reqinfo; + charset_filter_ctx_t *input_ctx, *output_ctx; + apr_status_t rv; + + ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r, + "uri: %s file: %s method: %d " + "imt: %s flags: %s%s%s %s->%s", + r->uri, + r->filename ? r->filename : "(none)", + r->method_number, + r->content_type ? r->content_type : "(unknown)", + r->main ? "S" : "", /* S if subrequest */ + r->prev ? "R" : "", /* R if redirect */ + r->proxyreq ? "P" : "", /* P if proxy */ + dc->charset_source, dc->charset_default); + + /* If we don't have a full directory configuration, bail out. + */ + if (!dc->charset_source || !dc->charset_default) { + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01448) + "incomplete configuration: src %s, dst %s", + dc->charset_source ? dc->charset_source : "unspecified", + dc->charset_default ? dc->charset_default : "unspecified"); + return DECLINED; + } + + /* catch proxy requests */ + if (r->proxyreq) { + return DECLINED; + } + + /* mod_rewrite indicators */ + if (r->filename + && (!strncmp(r->filename, "redirect:", 9) + || !strncmp(r->filename, "gone:", 5) + || !strncmp(r->filename, "passthrough:", 12) + || !strncmp(r->filename, "forbidden:", 10))) { + return DECLINED; + } + + /* no translation when server and network charsets are set to the same value */ + if (!strcasecmp(dc->charset_source, dc->charset_default)) { + return DECLINED; + } + + /* Get storage for the request data and the output filter context. + * We rarely need the input filter context, so allocate that separately. + */ + reqinfo = (charset_req_t *)apr_pcalloc(r->pool, + sizeof(charset_req_t) + + sizeof(charset_filter_ctx_t)); + output_ctx = (charset_filter_ctx_t *)(reqinfo + 1); + + reqinfo->dc = dc; + output_ctx->dc = dc; + output_ctx->tmpbb = apr_brigade_create(r->pool, + r->connection->bucket_alloc); + ap_set_module_config(r->request_config, &charset_lite_module, reqinfo); + + reqinfo->output_ctx = output_ctx; + + switch (r->method_number) { + case M_PUT: + case M_POST: + /* Set up input translation. Note: A request body can be included + * with the OPTIONS method, but for now we don't set up translation + * of it. + */ + input_ctx = apr_pcalloc(r->pool, sizeof(charset_filter_ctx_t)); + input_ctx->bb = apr_brigade_create(r->pool, + r->connection->bucket_alloc); + input_ctx->tmp = apr_palloc(r->pool, INPUT_XLATE_BUF_SIZE); + input_ctx->dc = dc; + reqinfo->input_ctx = input_ctx; + rv = apr_xlate_open(&input_ctx->xlate, dc->charset_source, + dc->charset_default, r->pool); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01449) + "can't open translation %s->%s", + dc->charset_default, dc->charset_source); + return HTTP_INTERNAL_SERVER_ERROR; + } + if (apr_xlate_sb_get(input_ctx->xlate, &input_ctx->is_sb) != APR_SUCCESS) { + input_ctx->is_sb = 0; + } + } + + return DECLINED; +} + +static int configured_in_list(request_rec *r, const char *filter_name, + struct ap_filter_t *filter_list) +{ + struct ap_filter_t *filter = filter_list; + + while (filter) { + if (!strcasecmp(filter_name, filter->frec->name)) { + return 1; + } + filter = filter->next; + } + return 0; +} + +static int configured_on_input(request_rec *r, const char *filter_name) +{ + return configured_in_list(r, filter_name, r->input_filters); +} + +static int configured_on_output(request_rec *r, const char *filter_name) +{ + return configured_in_list(r, filter_name, r->output_filters); +} + +/* xlate_insert_filter() is a filter hook which decides whether or not + * to insert a translation filter for the current request. + */ +static void xlate_insert_filter(request_rec *r) +{ + /* Hey... don't be so quick to use reqinfo->dc here; reqinfo may be NULL */ + charset_req_t *reqinfo = ap_get_module_config(r->request_config, + &charset_lite_module); + charset_dir_t *dc = ap_get_module_config(r->per_dir_config, + &charset_lite_module); + + if (dc && (dc->implicit_add == IA_NOIMPADD)) { + ap_log_rerror(APLOG_MARK, APLOG_TRACE6, 0, r, + "xlate output filter not added implicitly because " + "CharsetOptions included 'NoImplicitAdd'"); + return; + } + + if (reqinfo) { + if (reqinfo->output_ctx && !configured_on_output(r, XLATEOUT_FILTER_NAME)) { + ap_add_output_filter(XLATEOUT_FILTER_NAME, reqinfo->output_ctx, r, + r->connection); + } + ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r, + "xlate output filter not added implicitly because %s", + !reqinfo->output_ctx ? + "no output configuration available" : + "another module added the filter"); + + if (reqinfo->input_ctx && !configured_on_input(r, XLATEIN_FILTER_NAME)) { + ap_add_input_filter(XLATEIN_FILTER_NAME, reqinfo->input_ctx, r, + r->connection); + } + ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r, + "xlate input filter not added implicitly because %s", + !reqinfo->input_ctx ? + "no input configuration available" : + "another module added the filter"); + } +} + +/* stuff that sucks that I know of: + * + * bucket handling: + * why create an eos bucket when we see it come down the stream? just send the one + * passed as input... news flash: this will be fixed when xlate_out_filter() starts + * using the more generic xlate_brigade() + * + * translation mechanics: + * we don't handle characters that straddle more than two buckets; an error + * will be generated + */ + +static apr_status_t send_bucket_downstream(ap_filter_t *f, apr_bucket *b) +{ + charset_filter_ctx_t *ctx = f->ctx; + apr_status_t rv; + + APR_BRIGADE_INSERT_TAIL(ctx->tmpbb, b); + rv = ap_pass_brigade(f->next, ctx->tmpbb); + if (rv != APR_SUCCESS) { + ctx->ees = EES_DOWNSTREAM; + } + apr_brigade_cleanup(ctx->tmpbb); + return rv; +} + +/* send_downstream() is passed the translated data; it puts it in a single- + * bucket brigade and passes the brigade to the next filter + */ +static apr_status_t send_downstream(ap_filter_t *f, const char *tmp, apr_size_t len) +{ + request_rec *r = f->r; + conn_rec *c = r->connection; + apr_bucket *b; + + b = apr_bucket_transient_create(tmp, len, c->bucket_alloc); + return send_bucket_downstream(f, b); +} + +static apr_status_t send_eos(ap_filter_t *f) +{ + request_rec *r = f->r; + conn_rec *c = r->connection; + apr_bucket_brigade *bb; + apr_bucket *b; + charset_filter_ctx_t *ctx = f->ctx; + apr_status_t rv; + + bb = apr_brigade_create(r->pool, c->bucket_alloc); + b = apr_bucket_eos_create(c->bucket_alloc); + APR_BRIGADE_INSERT_TAIL(bb, b); + rv = ap_pass_brigade(f->next, bb); + if (rv != APR_SUCCESS) { + ctx->ees = EES_DOWNSTREAM; + } + return rv; +} + +static apr_status_t set_aside_partial_char(charset_filter_ctx_t *ctx, + const char *partial, + apr_size_t partial_len) +{ + apr_status_t rv; + + if (sizeof(ctx->buf) > partial_len) { + ctx->saved = partial_len; + memcpy(ctx->buf, partial, partial_len); + rv = APR_SUCCESS; + } + else { + rv = APR_INCOMPLETE; + ctx->ees = EES_LIMIT; /* we don't handle chars this wide which straddle + * buckets + */ + } + return rv; +} + +static apr_status_t finish_partial_char(charset_filter_ctx_t *ctx, + /* input buffer: */ + const char **cur_str, + apr_size_t *cur_len, + /* output buffer: */ + char **out_str, + apr_size_t *out_len) +{ + apr_status_t rv; + apr_size_t tmp_input_len; + + /* Keep adding bytes from the input string to the saved string until we + * 1) finish the input char + * 2) get an error + * or 3) run out of bytes to add + */ + + do { + ctx->buf[ctx->saved] = **cur_str; + ++ctx->saved; + ++*cur_str; + --*cur_len; + tmp_input_len = ctx->saved; + rv = apr_xlate_conv_buffer(ctx->xlate, + ctx->buf, + &tmp_input_len, + *out_str, + out_len); + } while (rv == APR_INCOMPLETE && *cur_len); + + if (rv == APR_SUCCESS) { + ctx->saved = 0; + } + else { + ctx->ees = EES_LIMIT; /* code isn't smart enough to handle chars + * straddling more than two buckets + */ + } + + return rv; +} + +static void log_xlate_error(ap_filter_t *f, apr_status_t rv) +{ + charset_filter_ctx_t *ctx = f->ctx; + const char *msg; + char msgbuf[100]; + apr_size_t len; + + switch(ctx->ees) { + case EES_LIMIT: + rv = 0; + msg = APLOGNO(02193) "xlate filter - a built-in restriction was encountered"; + break; + case EES_BAD_INPUT: + rv = 0; + msg = APLOGNO(02194) "xlate filter - an input character was invalid"; + break; + case EES_BUCKET_READ: + rv = 0; + msg = APLOGNO(02195) "xlate filter - bucket read routine failed"; + break; + case EES_INCOMPLETE_CHAR: + rv = 0; + strcpy(msgbuf, APLOGNO(02196) "xlate filter - incomplete char at end of input - "); + len = ctx->saved; + + /* We must ensure not to process more than what would fit in the + * remaining of the destination buffer, including terminating NULL */ + if (len > (sizeof(msgbuf) - strlen(msgbuf) - 1) / 2) + len = (sizeof(msgbuf) - strlen(msgbuf) - 1) / 2; + + ap_bin2hex(ctx->buf, len, msgbuf + strlen(msgbuf)); + msg = msgbuf; + break; + case EES_DOWNSTREAM: + msg = APLOGNO(02197) "xlate filter - an error occurred in a lower filter"; + break; + default: + msg = APLOGNO(02198) "xlate filter - returning error"; + } + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, f->r, APLOGNO(02997) "%s", msg); +} + +/* chk_filter_chain() is called once per filter instance; it tries to + * determine if the current filter instance should be disabled because + * its translation is incompatible with the translation of an existing + * instance of the translate filter + * + * Example bad scenario: + * + * configured filter chain for the request: + * INCLUDES XLATEOUT(8859-1->UTS-16) + * configured filter chain for the subrequest: + * XLATEOUT(8859-1->UTS-16) + * + * When the subrequest is processed, the filter chain will be + * XLATEOUT(8859-1->UTS-16) XLATEOUT(8859-1->UTS-16) + * This makes no sense, so the instance of XLATEOUT added for the + * subrequest will be noop-ed. + * + * Example good scenario: + * + * configured filter chain for the request: + * INCLUDES XLATEOUT(8859-1->UTS-16) + * configured filter chain for the subrequest: + * XLATEOUT(IBM-1047->8859-1) + * + * When the subrequest is processed, the filter chain will be + * XLATEOUT(IBM-1047->8859-1) XLATEOUT(8859-1->UTS-16) + * This makes sense, so the instance of XLATEOUT added for the + * subrequest will be left alone and it will translate from + * IBM-1047->8859-1. + */ +static void chk_filter_chain(ap_filter_t *f) +{ + ap_filter_t *curf; + charset_filter_ctx_t *curctx, *last_xlate_ctx = NULL, + *ctx = f->ctx; + int output = !strcasecmp(f->frec->name, XLATEOUT_FILTER_NAME); + + if (ctx->noop) { + return; + } + + /* walk the filter chain; see if it makes sense for our filter to + * do any translation + */ + curf = output ? f->r->output_filters : f->r->input_filters; + while (curf) { + if (!strcasecmp(curf->frec->name, f->frec->name) && + curf->ctx) { + curctx = (charset_filter_ctx_t *)curf->ctx; + if (!last_xlate_ctx) { + last_xlate_ctx = curctx; + } + else { + if (strcmp(last_xlate_ctx->dc->charset_default, + curctx->dc->charset_source)) { + /* incompatible translation + * if our filter instance is incompatible with an instance + * already in place, noop our instance + * Notes: + * . We are only willing to noop our own instance. + * . It is possible to noop another instance which has not + * yet run, but this is not currently implemented. + * Hopefully it will not be needed. + * . It is not possible to noop an instance which has + * already run. + */ + if (last_xlate_ctx == f->ctx) { + last_xlate_ctx->noop = 1; + if (APLOGrtrace1(f->r)) { + const char *symbol = output ? "->" : "<-"; + + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, + 0, f->r, APLOGNO(01451) + "%s %s - disabling " + "translation %s%s%s; existing " + "translation %s%s%s", + f->r->uri ? "uri" : "file", + f->r->uri ? f->r->uri : f->r->filename, + last_xlate_ctx->dc->charset_source, + symbol, + last_xlate_ctx->dc->charset_default, + curctx->dc->charset_source, + symbol, + curctx->dc->charset_default); + } + } + else { + const char *symbol = output ? "->" : "<-"; + + ap_log_rerror(APLOG_MARK, APLOG_ERR, + 0, f->r, APLOGNO(01452) + "chk_filter_chain() - can't disable " + "translation %s%s%s; existing " + "translation %s%s%s", + last_xlate_ctx->dc->charset_source, + symbol, + last_xlate_ctx->dc->charset_default, + curctx->dc->charset_source, + symbol, + curctx->dc->charset_default); + } + break; + } + } + } + curf = curf->next; + } +} + +/* xlate_brigade() is used to filter request and response bodies + * + * we'll stop when one of the following occurs: + * . we run out of buckets + * . we run out of space in the output buffer + * . we hit an error or metadata + * + * inputs: + * bb: brigade to process + * buffer: storage to hold the translated characters + * buffer_avail: size of buffer + * (and a few more uninteresting parms) + * + * outputs: + * return value: APR_SUCCESS or some error code + * bb: we've removed any buckets representing the + * translated characters; the eos bucket, if + * present, will be left in the brigade + * buffer: filled in with translated characters + * buffer_avail: updated with the bytes remaining + * hit_eos: did we hit an EOS bucket? + */ +static apr_status_t xlate_brigade(charset_filter_ctx_t *ctx, + apr_bucket_brigade *bb, + char *buffer, + apr_size_t *buffer_avail, + int *hit_eos) +{ + apr_bucket *b = NULL; /* set to NULL only to quiet some gcc */ + apr_bucket *consumed_bucket; + const char *bucket; + apr_size_t bytes_in_bucket; /* total bytes read from current bucket */ + apr_size_t bucket_avail; /* bytes left in current bucket */ + apr_status_t rv = APR_SUCCESS; + + *hit_eos = 0; + bucket_avail = 0; + consumed_bucket = NULL; + while (1) { + if (!bucket_avail) { /* no bytes left to process in the current bucket... */ + if (consumed_bucket) { + apr_bucket_delete(consumed_bucket); + consumed_bucket = NULL; + } + b = APR_BRIGADE_FIRST(bb); + if (b == APR_BRIGADE_SENTINEL(bb) || + APR_BUCKET_IS_METADATA(b)) { + break; + } + rv = apr_bucket_read(b, &bucket, &bytes_in_bucket, APR_BLOCK_READ); + if (rv != APR_SUCCESS) { + ctx->ees = EES_BUCKET_READ; + break; + } + bucket_avail = bytes_in_bucket; + consumed_bucket = b; /* for axing when we're done reading it */ + } + if (bucket_avail) { + /* We've got data, so translate it. */ + if (ctx->saved) { + /* Rats... we need to finish a partial character from the previous + * bucket. + * + * Strangely, finish_partial_char() increments the input buffer + * pointer but does not increment the output buffer pointer. + */ + apr_size_t old_buffer_avail = *buffer_avail; + rv = finish_partial_char(ctx, + &bucket, &bucket_avail, + &buffer, buffer_avail); + buffer += old_buffer_avail - *buffer_avail; + } + else { + apr_size_t old_buffer_avail = *buffer_avail; + apr_size_t old_bucket_avail = bucket_avail; + rv = apr_xlate_conv_buffer(ctx->xlate, + bucket, &bucket_avail, + buffer, + buffer_avail); + buffer += old_buffer_avail - *buffer_avail; + bucket += old_bucket_avail - bucket_avail; + + if (rv == APR_INCOMPLETE) { /* partial character at end of input */ + /* We need to save the final byte(s) for next time; we can't + * convert it until we look at the next bucket. + */ + rv = set_aside_partial_char(ctx, bucket, bucket_avail); + bucket_avail = 0; + } + } + if (rv != APR_SUCCESS) { + /* bad input byte or partial char too big to store */ + break; + } + if (*buffer_avail < XLATE_MIN_BUFF_LEFT) { + /* if any data remains in the current bucket, split there */ + if (bucket_avail) { + apr_bucket_split(b, bytes_in_bucket - bucket_avail); + } + apr_bucket_delete(b); + break; + } + } + } + + if (!APR_BRIGADE_EMPTY(bb)) { + b = APR_BRIGADE_FIRST(bb); + if (APR_BUCKET_IS_EOS(b)) { + /* Leave the eos bucket in the brigade for reporting to + * subsequent filters. + */ + *hit_eos = 1; + if (ctx->saved) { + /* Oops... we have a partial char from the previous bucket + * that won't be completed because there's no more data. + */ + rv = APR_INCOMPLETE; + ctx->ees = EES_INCOMPLETE_CHAR; + } + } + } + + return rv; +} + +/* xlate_out_filter() handles (almost) arbitrary conversions from one charset + * to another... + * translation is determined in the fixup hook (find_code_page), which is + * where the filter's context data is set up... the context data gives us + * the translation handle + */ +static apr_status_t xlate_out_filter(ap_filter_t *f, apr_bucket_brigade *bb) +{ + charset_req_t *reqinfo = ap_get_module_config(f->r->request_config, + &charset_lite_module); + charset_dir_t *dc = ap_get_module_config(f->r->per_dir_config, + &charset_lite_module); + charset_filter_ctx_t *ctx = f->ctx; + apr_bucket *dptr, *consumed_bucket; + const char *cur_str; + apr_size_t cur_len, cur_avail; + char tmp[OUTPUT_XLATE_BUF_SIZE]; + apr_size_t space_avail; + int done; + apr_status_t rv = APR_SUCCESS; + + if (!ctx) { + /* this is SetOutputFilter path; grab the preallocated context, + * if any; note that if we decided not to do anything in an earlier + * handler, we won't even have a reqinfo + */ + if (reqinfo) { + ctx = f->ctx = reqinfo->output_ctx; + reqinfo->output_ctx = NULL; /* prevent SNAFU if user coded us twice + * in the filter chain; we can't have two + * instances using the same context + */ + } + if (!ctx) { /* no idea how to translate; don't do anything */ + ctx = f->ctx = apr_pcalloc(f->r->pool, sizeof(charset_filter_ctx_t)); + ctx->dc = dc; + ctx->noop = 1; + } + } + + /* Check the mime type to see if translation should be performed. + */ + if (!ctx->noop && ctx->xlate == NULL) { + const char *mime_type = f->r->content_type; + + if (mime_type && (ap_cstr_casecmpn(mime_type, "text/", 5) == 0 || +#if APR_CHARSET_EBCDIC + /* On an EBCDIC machine, be willing to translate mod_autoindex- + * generated output. Otherwise, it doesn't look too cool. + * + * XXX This isn't a perfect fix because this doesn't trigger us + * to convert from the charset of the source code to ASCII. The + * general solution seems to be to allow a generator to set an + * indicator in the r specifying that the body is coded in the + * implementation character set (i.e., the charset of the source + * code). This would get several different types of documents + * translated properly: mod_autoindex output, mod_status output, + * mod_info output, hard-coded error documents, etc. + */ + strcmp(mime_type, DIR_MAGIC_TYPE) == 0 || +#endif + ap_cstr_casecmpn(mime_type, "message/", 8) == 0 || + dc->force_xlate == FX_FORCE)) { + + rv = apr_xlate_open(&ctx->xlate, + dc->charset_default, dc->charset_source, f->r->pool); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, f->r, APLOGNO(01453) + "can't open translation %s->%s", + dc->charset_source, dc->charset_default); + ctx->noop = 1; + } + else { + if (apr_xlate_sb_get(ctx->xlate, &ctx->is_sb) != APR_SUCCESS) { + ctx->is_sb = 0; + } + } + } + else { + ctx->noop = 1; + if (mime_type) { + ap_log_rerror(APLOG_MARK, APLOG_TRACE6, 0, f->r, + "mime type is %s; no translation selected", + mime_type); + } + } + } + + ap_log_rerror(APLOG_MARK, APLOG_TRACE6, 0, f->r, + "xlate_out_filter() - " + "charset_source: %s charset_default: %s", + dc && dc->charset_source ? dc->charset_source : "(none)", + dc && dc->charset_default ? dc->charset_default : "(none)"); + + if (!ctx->ran) { /* filter never ran before */ + chk_filter_chain(f); + ctx->ran = 1; + if (!ctx->noop && !ctx->is_sb) { + /* We're not converting between two single-byte charsets, so unset + * Content-Length since it is unlikely to remain the same. + */ + apr_table_unset(f->r->headers_out, "Content-Length"); + } + } + + if (ctx->noop) { + return ap_pass_brigade(f->next, bb); + } + + dptr = APR_BRIGADE_FIRST(bb); + done = 0; + cur_len = 0; + space_avail = sizeof(tmp); + consumed_bucket = NULL; + while (!done) { + if (!cur_len) { /* no bytes left to process in the current bucket... */ + if (consumed_bucket) { + apr_bucket_delete(consumed_bucket); + consumed_bucket = NULL; + } + if (dptr == APR_BRIGADE_SENTINEL(bb)) { + break; + } + if (APR_BUCKET_IS_EOS(dptr)) { + cur_len = -1; /* XXX yuck, but that tells us to send + * eos down; when we minimize our bb construction + * we'll fix this crap */ + if (ctx->saved) { + /* Oops... we have a partial char from the previous bucket + * that won't be completed because there's no more data. + */ + rv = APR_INCOMPLETE; + ctx->ees = EES_INCOMPLETE_CHAR; + } + break; + } + if (APR_BUCKET_IS_METADATA(dptr)) { + apr_bucket *metadata_bucket; + metadata_bucket = dptr; + dptr = APR_BUCKET_NEXT(dptr); + APR_BUCKET_REMOVE(metadata_bucket); + rv = send_bucket_downstream(f, metadata_bucket); + if (rv != APR_SUCCESS) { + done = 1; + } + continue; + } + rv = apr_bucket_read(dptr, &cur_str, &cur_len, APR_BLOCK_READ); + if (rv != APR_SUCCESS) { + ctx->ees = EES_BUCKET_READ; + break; + } + consumed_bucket = dptr; /* for axing when we're done reading it */ + dptr = APR_BUCKET_NEXT(dptr); /* get ready for when we access the + * next bucket */ + } + /* Try to fill up our tmp buffer with translated data. */ + cur_avail = cur_len; + + if (cur_len) { /* maybe we just hit the end of a pipe (len = 0) ? */ + if (ctx->saved) { + /* Rats... we need to finish a partial character from the previous + * bucket. + */ + char *tmp_tmp; + + tmp_tmp = tmp + sizeof(tmp) - space_avail; + rv = finish_partial_char(ctx, + &cur_str, &cur_len, + &tmp_tmp, &space_avail); + } + else { + rv = apr_xlate_conv_buffer(ctx->xlate, + cur_str, &cur_avail, + tmp + sizeof(tmp) - space_avail, &space_avail); + + /* Update input ptr and len after consuming some bytes */ + cur_str += cur_len - cur_avail; + cur_len = cur_avail; + + if (rv == APR_INCOMPLETE) { /* partial character at end of input */ + /* We need to save the final byte(s) for next time; we can't + * convert it until we look at the next bucket. + */ + rv = set_aside_partial_char(ctx, cur_str, cur_len); + cur_len = 0; + } + } + } + + if (rv != APR_SUCCESS) { + /* bad input byte or partial char too big to store */ + done = 1; + } + + if (space_avail < XLATE_MIN_BUFF_LEFT) { + /* It is time to flush, as there is not enough space left in the + * current output buffer to bother with converting more data. + */ + rv = send_downstream(f, tmp, sizeof(tmp) - space_avail); + if (rv != APR_SUCCESS) { + done = 1; + } + + /* tmp is now empty */ + space_avail = sizeof(tmp); + } + } + + if (rv == APR_SUCCESS) { + if (space_avail < sizeof(tmp)) { /* gotta write out what we converted */ + rv = send_downstream(f, tmp, sizeof(tmp) - space_avail); + } + } + if (rv == APR_SUCCESS) { + if (cur_len == -1) { + rv = send_eos(f); + } + } + else { + log_xlate_error(f, rv); + } + + return rv; +} + +static apr_status_t xlate_in_filter(ap_filter_t *f, apr_bucket_brigade *bb, + ap_input_mode_t mode, apr_read_type_e block, + apr_off_t readbytes) +{ + apr_status_t rv; + charset_req_t *reqinfo = ap_get_module_config(f->r->request_config, + &charset_lite_module); + charset_dir_t *dc = ap_get_module_config(f->r->per_dir_config, + &charset_lite_module); + charset_filter_ctx_t *ctx = f->ctx; + apr_size_t buffer_size; + int hit_eos; + + /* just get out of the way of things we don't want. */ + if (mode != AP_MODE_READBYTES) { + return ap_get_brigade(f->next, bb, mode, block, readbytes); + } + + if (!ctx) { + /* this is SetInputFilter path; grab the preallocated context, + * if any; note that if we decided not to do anything in an earlier + * handler, we won't even have a reqinfo + */ + if (reqinfo) { + ctx = f->ctx = reqinfo->input_ctx; + reqinfo->input_ctx = NULL; /* prevent SNAFU if user coded us twice + * in the filter chain; we can't have two + * instances using the same context + */ + } + if (!ctx) { /* no idea how to translate; don't do anything */ + ctx = f->ctx = apr_pcalloc(f->r->pool, sizeof(charset_filter_ctx_t)); + ctx->dc = dc; + ctx->noop = 1; + } + } + + ap_log_rerror(APLOG_MARK, APLOG_TRACE6, 0, f->r, + "xlate_in_filter() - " + "charset_source: %s charset_default: %s", + dc && dc->charset_source ? dc->charset_source : "(none)", + dc && dc->charset_default ? dc->charset_default : "(none)"); + + if (!ctx->ran) { /* filter never ran before */ + chk_filter_chain(f); + ctx->ran = 1; + if (!ctx->noop && !ctx->is_sb + && apr_table_get(f->r->headers_in, "Content-Length")) { + /* A Content-Length header is present, but it won't be valid after + * conversion because we're not converting between two single-byte + * charsets. This will affect most CGI scripts and may affect + * some modules. + * Content-Length can't be unset here because that would break + * being able to read the request body. + * Processing of chunked request bodies is not impacted by this + * filter since the length was not declared anyway. + */ + ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, f->r, + "Request body length may change, resulting in " + "misprocessing by some modules or scripts"); + } + } + + if (ctx->noop) { + return ap_get_brigade(f->next, bb, mode, block, readbytes); + } + + if (APR_BRIGADE_EMPTY(ctx->bb)) { + if ((rv = ap_get_brigade(f->next, bb, mode, block, + readbytes)) != APR_SUCCESS) { + return rv; + } + } + else { + APR_BRIGADE_PREPEND(bb, ctx->bb); /* first use the leftovers */ + } + + buffer_size = INPUT_XLATE_BUF_SIZE; + rv = xlate_brigade(ctx, bb, ctx->tmp, &buffer_size, &hit_eos); + if (rv == APR_SUCCESS) { + if (!hit_eos) { + /* move anything leftover into our context for next time; + * we don't currently "set aside" since the data came from + * down below, but I suspect that for long-term we need to + * do that + */ + APR_BRIGADE_CONCAT(ctx->bb, bb); + } + if (buffer_size < INPUT_XLATE_BUF_SIZE) { /* do we have output? */ + apr_bucket *e; + + e = apr_bucket_heap_create(ctx->tmp, + INPUT_XLATE_BUF_SIZE - buffer_size, + NULL, f->r->connection->bucket_alloc); + /* make sure we insert at the head, because there may be + * an eos bucket already there, and the eos bucket should + * come after the data + */ + APR_BRIGADE_INSERT_HEAD(bb, e); + } + else { + /* XXX need to get some more data... what if the last brigade + * we got had only the first byte of a multibyte char? we need + * to grab more data from the network instead of returning an + * empty brigade + */ + } + /* If we have any metadata at the head of ctx->bb, go ahead and move it + * onto the end of bb to be returned to our caller. + */ + if (!APR_BRIGADE_EMPTY(ctx->bb)) { + apr_bucket *b = APR_BRIGADE_FIRST(ctx->bb); + while (b != APR_BRIGADE_SENTINEL(ctx->bb) + && APR_BUCKET_IS_METADATA(b)) { + APR_BUCKET_REMOVE(b); + APR_BRIGADE_INSERT_TAIL(bb, b); + b = APR_BRIGADE_FIRST(ctx->bb); + } + } + } + else { + log_xlate_error(f, rv); + } + + return rv; +} + +static const command_rec cmds[] = +{ + AP_INIT_TAKE1("CharsetSourceEnc", + add_charset_source, + NULL, + OR_FILEINFO, + "source (html,cgi,ssi) file charset"), + AP_INIT_TAKE1("CharsetDefault", + add_charset_default, + NULL, + OR_FILEINFO, + "name of default charset"), + AP_INIT_ITERATE("CharsetOptions", + add_charset_options, + NULL, + OR_FILEINFO, + "valid options: ImplicitAdd, NoImplicitAdd, TranslateAllMimeTypes, " + "NoTranslateAllMimeTypes"), + {NULL} +}; + +static void charset_register_hooks(apr_pool_t *p) +{ + ap_hook_fixups(find_code_page, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_insert_filter(xlate_insert_filter, NULL, NULL, APR_HOOK_REALLY_LAST); + ap_register_output_filter(XLATEOUT_FILTER_NAME, xlate_out_filter, NULL, + AP_FTYPE_RESOURCE); + ap_register_input_filter(XLATEIN_FILTER_NAME, xlate_in_filter, NULL, + AP_FTYPE_RESOURCE); +} + +AP_DECLARE_MODULE(charset_lite) = +{ + STANDARD20_MODULE_STUFF, + create_charset_dir_conf, + merge_charset_dir_conf, + NULL, + NULL, + cmds, + charset_register_hooks +}; + |