diff options
Diffstat (limited to 'modules/generators/cgi_common.h')
| -rw-r--r-- | modules/generators/cgi_common.h | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/modules/generators/cgi_common.h b/modules/generators/cgi_common.h new file mode 100644 index 0000000..66f9418 --- /dev/null +++ b/modules/generators/cgi_common.h @@ -0,0 +1,639 @@ +/* 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 "apr.h" +#include "apr_strings.h" +#include "apr_buckets.h" +#include "apr_lib.h" +#include "apr_poll.h" + +#define APR_WANT_STRFUNC +#define APR_WANT_MEMFUNC +#include "apr_want.h" + +#include "httpd.h" +#include "util_filter.h" +#include "util_script.h" + +static APR_OPTIONAL_FN_TYPE(ap_ssi_get_tag_and_value) *cgi_pfn_gtv; +static APR_OPTIONAL_FN_TYPE(ap_ssi_parse_string) *cgi_pfn_ps; + +/* These functions provided by mod_cgi.c/mod_cgid.c still. */ +static int log_script(request_rec *r, cgi_server_conf * conf, int ret, + char *dbuf, const char *sbuf, apr_bucket_brigade *bb, + apr_file_t *script_err); +static apr_status_t include_cgi(include_ctx_t *ctx, ap_filter_t *f, + apr_bucket_brigade *bb, char *s); +static apr_status_t include_cmd(include_ctx_t *ctx, ap_filter_t *f, + apr_bucket_brigade *bb, const char *command); + +/* Read and discard all output from the brigade. Note that with the + * CGI bucket, the brigade will become empty once the script's stdout + * is closed (or on error/timeout), but the stderr output may not have + * been entirely captured at this point. */ +static void discard_script_output(apr_bucket_brigade *bb) +{ + apr_bucket *e; + const char *buf; + apr_size_t len; + + for (e = APR_BRIGADE_FIRST(bb); + e != APR_BRIGADE_SENTINEL(bb) && !APR_BUCKET_IS_EOS(e); + e = APR_BRIGADE_FIRST(bb)) + { + if (apr_bucket_read(e, &buf, &len, APR_BLOCK_READ)) { + break; + } + apr_bucket_delete(e); + } +} + +static int log_scripterror(request_rec *r, cgi_server_conf *conf, int ret, + apr_status_t rv, const char *logno, + const char *error) +{ + apr_file_t *f = NULL; + apr_finfo_t finfo; + char time_str[APR_CTIME_LEN]; + + /* Intentional no APLOGNO */ + /* Callee provides APLOGNO in error text */ + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, + "%sstderr from %s: %s", logno ? logno : "", r->filename, error); + + /* XXX Very expensive mainline case! Open, then getfileinfo! */ + if (!conf->logname || + ((apr_stat(&finfo, conf->logname, + APR_FINFO_SIZE, r->pool) == APR_SUCCESS) && + (finfo.size > conf->logbytes)) || + (apr_file_open(&f, conf->logname, + APR_APPEND|APR_WRITE|APR_CREATE, APR_OS_DEFAULT, + r->pool) != APR_SUCCESS)) { + return ret; + } + + /* "%% [Wed Jun 19 10:53:21 1996] GET /cgi-bin/printenv HTTP/1.0" */ + apr_ctime(time_str, apr_time_now()); + apr_file_printf(f, "%%%% [%s] %s %s%s%s %s\n", time_str, r->method, r->uri, + r->args ? "?" : "", r->args ? r->args : "", r->protocol); + /* "%% 500 /usr/local/apache/cgi-bin */ + apr_file_printf(f, "%%%% %d %s\n", ret, r->filename); + + apr_file_printf(f, "%%error\n%s\n", error); + + apr_file_close(f); + return ret; +} + +/* Soak up stderr from a script and redirect it to the error log. + */ +static apr_status_t log_script_err(request_rec *r, apr_file_t *script_err) +{ + char argsbuffer[HUGE_STRING_LEN]; + char *newline; + apr_status_t rv; + cgi_server_conf *conf = ap_get_module_config(r->server->module_config, &cgi_module); + + while ((rv = apr_file_gets(argsbuffer, HUGE_STRING_LEN, + script_err)) == APR_SUCCESS) { + + newline = strchr(argsbuffer, '\n'); + if (newline) { + char *prev = newline - 1; + if (prev >= argsbuffer && *prev == '\r') { + newline = prev; + } + + *newline = '\0'; + } + log_scripterror(r, conf, r->status, 0, APLOGNO(01215), argsbuffer); + } + + return rv; +} + +static apr_status_t cgi_handle_exec(include_ctx_t *ctx, ap_filter_t *f, + apr_bucket_brigade *bb) +{ + char *tag = NULL; + char *tag_val = NULL; + request_rec *r = f->r; + char *file = r->filename; + char parsed_string[MAX_STRING_LEN]; + + if (!ctx->argc) { + ap_log_rerror(APLOG_MARK, + (ctx->flags & SSI_FLAG_PRINTING) + ? APLOG_ERR : APLOG_WARNING, + 0, r, APLOGNO(03195) + "missing argument for exec element in %s", r->filename); + } + + if (!(ctx->flags & SSI_FLAG_PRINTING)) { + return APR_SUCCESS; + } + + if (!ctx->argc) { + SSI_CREATE_ERROR_BUCKET(ctx, f, bb); + return APR_SUCCESS; + } + + if (ctx->flags & SSI_FLAG_NO_EXEC) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01228) "exec used but not allowed " + "in %s", r->filename); + SSI_CREATE_ERROR_BUCKET(ctx, f, bb); + return APR_SUCCESS; + } + + while (1) { + cgi_pfn_gtv(ctx, &tag, &tag_val, SSI_VALUE_DECODED); + if (!tag || !tag_val) { + break; + } + + if (!strcmp(tag, "cmd")) { + apr_status_t rv; + + cgi_pfn_ps(ctx, tag_val, parsed_string, sizeof(parsed_string), + SSI_EXPAND_LEAVE_NAME); + + rv = include_cmd(ctx, f, bb, parsed_string); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01229) "execution failure " + "for parameter \"%s\" to tag exec in file %s", + tag, r->filename); + SSI_CREATE_ERROR_BUCKET(ctx, f, bb); + break; + } + } + else if (!strcmp(tag, "cgi")) { + apr_status_t rv; + + cgi_pfn_ps(ctx, tag_val, parsed_string, sizeof(parsed_string), + SSI_EXPAND_DROP_NAME); + + rv = include_cgi(ctx, f, bb, parsed_string); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01230) "invalid CGI ref " + "\"%s\" in %s", tag_val, file); + SSI_CREATE_ERROR_BUCKET(ctx, f, bb); + break; + } + } + else { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01231) "unknown parameter " + "\"%s\" to tag exec in %s", tag, file); + SSI_CREATE_ERROR_BUCKET(ctx, f, bb); + break; + } + } + + return APR_SUCCESS; +} + +/* Hook to register exec= handling with mod_include. */ +static void cgi_optfns_retrieve(void) +{ + APR_OPTIONAL_FN_TYPE(ap_register_include_handler) *cgi_pfn_reg_with_ssi; + + cgi_pfn_reg_with_ssi = APR_RETRIEVE_OPTIONAL_FN(ap_register_include_handler); + cgi_pfn_gtv = APR_RETRIEVE_OPTIONAL_FN(ap_ssi_get_tag_and_value); + cgi_pfn_ps = APR_RETRIEVE_OPTIONAL_FN(ap_ssi_parse_string); + + if (cgi_pfn_reg_with_ssi && cgi_pfn_gtv && cgi_pfn_ps) { + /* Required by mod_include filter. This is how mod_cgi registers + * with mod_include to provide processing of the exec directive. + */ + cgi_pfn_reg_with_ssi("exec", cgi_handle_exec); + } +} + +#ifdef WANT_CGI_BUCKET +/* A CGI bucket type is needed to catch any output to stderr from the + * script; see PR 22030. */ +static const apr_bucket_type_t bucket_type_cgi; + +struct cgi_bucket_data { + apr_pollset_t *pollset; + request_rec *r; + apr_interval_time_t timeout; +}; + +/* Create a CGI bucket using pipes from script stdout 'out' + * and stderr 'err', for request 'r'. */ +static apr_bucket *cgi_bucket_create(request_rec *r, + apr_interval_time_t timeout, + apr_file_t *out, apr_file_t *err, + apr_bucket_alloc_t *list) +{ + apr_bucket *b = apr_bucket_alloc(sizeof(*b), list); + apr_status_t rv; + apr_pollfd_t fd; + struct cgi_bucket_data *data = apr_palloc(r->pool, sizeof *data); + + /* Disable APR timeout handling since we'll use poll() entirely. */ + apr_file_pipe_timeout_set(out, 0); + apr_file_pipe_timeout_set(err, 0); + + APR_BUCKET_INIT(b); + b->free = apr_bucket_free; + b->list = list; + b->type = &bucket_type_cgi; + b->length = (apr_size_t)(-1); + b->start = -1; + + /* Create the pollset */ + rv = apr_pollset_create(&data->pollset, 2, r->pool, 0); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01217) + "apr_pollset_create(); check system or user limits"); + return NULL; + } + + fd.desc_type = APR_POLL_FILE; + fd.reqevents = APR_POLLIN; + fd.p = r->pool; + fd.desc.f = out; /* script's stdout */ + fd.client_data = (void *)1; + rv = apr_pollset_add(data->pollset, &fd); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01218) + "apr_pollset_add(); check system or user limits"); + return NULL; + } + + fd.desc.f = err; /* script's stderr */ + fd.client_data = (void *)2; + rv = apr_pollset_add(data->pollset, &fd); + if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01219) + "apr_pollset_add(); check system or user limits"); + return NULL; + } + + data->r = r; + data->timeout = timeout; + b->data = data; + return b; +} + +/* Create a duplicate CGI bucket using given bucket data */ +static apr_bucket *cgi_bucket_dup(struct cgi_bucket_data *data, + apr_bucket_alloc_t *list) +{ + apr_bucket *b = apr_bucket_alloc(sizeof(*b), list); + APR_BUCKET_INIT(b); + b->free = apr_bucket_free; + b->list = list; + b->type = &bucket_type_cgi; + b->length = (apr_size_t)(-1); + b->start = -1; + b->data = data; + return b; +} + +/* Handle stdout from CGI child. Duplicate of logic from the _read + * method of the real APR pipe bucket implementation. */ +static apr_status_t cgi_read_stdout(apr_bucket *a, apr_file_t *out, + const char **str, apr_size_t *len) +{ + char *buf; + apr_status_t rv; + + *str = NULL; + *len = APR_BUCKET_BUFF_SIZE; + buf = apr_bucket_alloc(*len, a->list); /* XXX: check for failure? */ + + rv = apr_file_read(out, buf, len); + + if (rv != APR_SUCCESS && rv != APR_EOF) { + apr_bucket_free(buf); + return rv; + } + + if (*len > 0) { + struct cgi_bucket_data *data = a->data; + apr_bucket_heap *h; + + /* Change the current bucket to refer to what we read */ + a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free); + h = a->data; + h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */ + *str = buf; + APR_BUCKET_INSERT_AFTER(a, cgi_bucket_dup(data, a->list)); + } + else { + apr_bucket_free(buf); + a = apr_bucket_immortal_make(a, "", 0); + *str = a->data; + } + return rv; +} + +/* Read method of CGI bucket: polls on stderr and stdout of the child, + * sending any stderr output immediately away to the error log. */ +static apr_status_t cgi_bucket_read(apr_bucket *b, const char **str, + apr_size_t *len, apr_read_type_e block) +{ + struct cgi_bucket_data *data = b->data; + apr_interval_time_t timeout = 0; + apr_status_t rv; + int gotdata = 0; + + if (block != APR_NONBLOCK_READ) { + timeout = data->timeout > 0 ? data->timeout : data->r->server->timeout; + } + + do { + const apr_pollfd_t *results; + apr_int32_t num; + + rv = apr_pollset_poll(data->pollset, timeout, &num, &results); + if (APR_STATUS_IS_TIMEUP(rv)) { + if (timeout) { + ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, data->r, APLOGNO(01220) + "Timeout waiting for output from CGI script %s", + data->r->filename); + return rv; + } + else { + return APR_EAGAIN; + } + } + else if (APR_STATUS_IS_EINTR(rv)) { + continue; + } + else if (rv != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, data->r, APLOGNO(01221) + "poll failed waiting for CGI child"); + return rv; + } + + for (; num; num--, results++) { + if (results[0].client_data == (void *)1) { + /* stdout */ + rv = cgi_read_stdout(b, results[0].desc.f, str, len); + if (APR_STATUS_IS_EOF(rv)) { + rv = APR_SUCCESS; + } + gotdata = 1; + } else { + /* stderr */ + apr_status_t rv2 = log_script_err(data->r, results[0].desc.f); + if (APR_STATUS_IS_EOF(rv2)) { + apr_pollset_remove(data->pollset, &results[0]); + } + } + } + + } while (!gotdata); + + return rv; +} + +static const apr_bucket_type_t bucket_type_cgi = { + "CGI", 5, APR_BUCKET_DATA, + apr_bucket_destroy_noop, + cgi_bucket_read, + apr_bucket_setaside_notimpl, + apr_bucket_split_notimpl, + apr_bucket_copy_notimpl +}; + +#endif /* WANT_CGI_BUCKET */ + +/* Handle the CGI response output, having set up the brigade with the + * CGI or PIPE bucket as appropriate. */ +static int cgi_handle_response(request_rec *r, int nph, apr_bucket_brigade *bb, + apr_interval_time_t timeout, cgi_server_conf *conf, + char *logdata, apr_file_t *script_err) +{ + apr_status_t rv; + + /* Handle script return... */ + if (!nph) { + const char *location; + char sbuf[MAX_STRING_LEN]; + int ret; + + ret = ap_scan_script_header_err_brigade_ex(r, bb, sbuf, + APLOG_MODULE_INDEX); + + /* xCGI has its own body framing mechanism which we don't + * match against any provided Content-Length, so let the + * core determine C-L vs T-E based on what's actually sent. + */ + if (!apr_table_get(r->subprocess_env, AP_TRUST_CGILIKE_CL_ENVVAR)) + apr_table_unset(r->headers_out, "Content-Length"); + apr_table_unset(r->headers_out, "Transfer-Encoding"); + + if (ret != OK) { + /* In the case of a timeout reading script output, clear + * the brigade to avoid a second attempt to read the + * output. */ + if (ret == HTTP_GATEWAY_TIME_OUT) { + apr_brigade_cleanup(bb); + } + + ret = log_script(r, conf, ret, logdata, sbuf, bb, script_err); + + /* + * ret could be HTTP_NOT_MODIFIED in the case that the CGI script + * does not set an explicit status and ap_meets_conditions, which + * is called by ap_scan_script_header_err_brigade, detects that + * the conditions of the requests are met and the response is + * not modified. + * In this case set r->status and return OK in order to prevent + * running through the error processing stack as this would + * break with mod_cache, if the conditions had been set by + * mod_cache itself to validate a stale entity. + * BTW: We circumvent the error processing stack anyway if the + * CGI script set an explicit status code (whatever it is) and + * the only possible values for ret here are: + * + * HTTP_NOT_MODIFIED (set by ap_meets_conditions) + * HTTP_PRECONDITION_FAILED (set by ap_meets_conditions) + * HTTP_INTERNAL_SERVER_ERROR (if something went wrong during the + * processing of the response of the CGI script, e.g broken headers + * or a crashed CGI process). + */ + if (ret == HTTP_NOT_MODIFIED) { + r->status = ret; + return OK; + } + + return ret; + } + + location = apr_table_get(r->headers_out, "Location"); + + if (location && r->status == 200) { + /* For a redirect whether internal or not, discard any + * remaining stdout from the script, and log any remaining + * stderr output, as normal. */ + discard_script_output(bb); + apr_brigade_destroy(bb); + + if (script_err) { + apr_file_pipe_timeout_set(script_err, timeout); + log_script_err(r, script_err); + } + } + + if (location && location[0] == '/' && r->status == 200) { + /* This redirect needs to be a GET no matter what the original + * method was. + */ + r->method = "GET"; + r->method_number = M_GET; + + /* We already read the message body (if any), so don't allow + * the redirected request to think it has one. We can ignore + * Transfer-Encoding, since we used REQUEST_CHUNKED_ERROR. + */ + apr_table_unset(r->headers_in, "Content-Length"); + + ap_internal_redirect_handler(location, r); + return OK; + } + else if (location && r->status == 200) { + /* XXX: Note that if a script wants to produce its own Redirect + * body, it now has to explicitly *say* "Status: 302" + */ + discard_script_output(bb); + apr_brigade_destroy(bb); + return HTTP_MOVED_TEMPORARILY; + } + + rv = ap_pass_brigade(r->output_filters, bb); + } + else /* nph */ { + struct ap_filter_t *cur; + + /* get rid of all filters up through protocol... since we + * haven't parsed off the headers, there is no way they can + * work + */ + + cur = r->proto_output_filters; + while (cur && cur->frec->ftype < AP_FTYPE_CONNECTION) { + cur = cur->next; + } + r->output_filters = r->proto_output_filters = cur; + + rv = ap_pass_brigade(r->output_filters, bb); + } + + /* don't soak up script output if errors occurred writing it + * out... otherwise, we prolong the life of the script when the + * connection drops or we stopped sending output for some other + * reason */ + if (script_err && rv == APR_SUCCESS && !r->connection->aborted) { + apr_file_pipe_timeout_set(script_err, timeout); + log_script_err(r, script_err); + } + + if (script_err) apr_file_close(script_err); + + return OK; /* NOT r->status, even if it has changed. */ +} + +/* Read the request body and write it to fd 'script_out', using 'bb' + * as temporary bucket brigade. If 'logbuf' is non-NULL, the first + * logbufbytes of stdout are stored in logbuf. */ +static apr_status_t cgi_handle_request(request_rec *r, apr_file_t *script_out, + apr_bucket_brigade *bb, + char *logbuf, apr_size_t logbufbytes) +{ + int seen_eos = 0; + int child_stopped_reading = 0; + apr_status_t rv; + int dbpos = 0; + + do { + apr_bucket *bucket; + + rv = ap_get_brigade(r->input_filters, bb, AP_MODE_READBYTES, + APR_BLOCK_READ, HUGE_STRING_LEN); + + if (rv != APR_SUCCESS) { + return rv; + } + + for (bucket = APR_BRIGADE_FIRST(bb); + bucket != APR_BRIGADE_SENTINEL(bb); + bucket = APR_BUCKET_NEXT(bucket)) + { + const char *data; + apr_size_t len; + + if (APR_BUCKET_IS_EOS(bucket)) { + seen_eos = 1; + break; + } + + /* We can't do much with this. */ + if (APR_BUCKET_IS_FLUSH(bucket)) { + continue; + } + + /* If the child stopped, we still must read to EOS. */ + if (child_stopped_reading) { + continue; + } + + /* read */ + rv = apr_bucket_read(bucket, &data, &len, APR_BLOCK_READ); + if (rv) { + return rv; + } + + if (logbufbytes && dbpos < logbufbytes) { + int cursize; + + if ((dbpos + len) > logbufbytes) { + cursize = logbufbytes - dbpos; + } + else { + cursize = len; + } + memcpy(logbuf + dbpos, data, cursize); + dbpos += cursize; + } + + /* Keep writing data to the child until done or too much time + * elapses with no progress or an error occurs. + */ + rv = apr_file_write_full(script_out, data, len, NULL); + + if (rv != APR_SUCCESS) { + /* silly script stopped reading, soak up remaining message */ + child_stopped_reading = 1; + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(02651) + "Error writing request body to script %s", + r->filename); + } + } + apr_brigade_cleanup(bb); + } + while (!seen_eos); + + if (logbuf) { + logbuf[dbpos] = '\0'; + } + + return APR_SUCCESS; +} |