1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "apr_strings.h"
18
19#include "httpd.h"
20#include "http_config.h"
21#include "http_log.h"
22#include "http_protocol.h"
23#include "http_request.h"
24#include "ap_expr.h"
25
26extern module AP_MODULE_DECLARE_DATA log_debug_module;
27
28typedef struct {
29    ap_expr_info_t *msg_expr;
30    ap_expr_info_t *condition;
31    const char *hook;
32} msg_entry;
33
34typedef struct {
35    apr_array_header_t *entries;
36} log_debug_dirconf;
37
38static const char *allhooks = "all";
39static const char * const hooks[] = {
40    "log_transaction",      /*  0 */
41    "quick_handler",        /*  1 */
42    "handler",              /*  2 */
43    "translate_name",       /*  3 */
44    "map_to_storage",       /*  4 */
45    "fixups",               /*  5 */
46    "type_checker",         /*  6 */
47    "check_access",         /*  7 */
48    "check_access_ex",      /*  8 */
49    "check_authn",          /*  9 */
50    "check_authz",          /* 10 */
51    "insert_filter",        /* 11 */
52    NULL
53};
54
55static void do_debug_log(request_rec *r, const char *hookname)
56{
57    log_debug_dirconf *dconf = ap_get_module_config(r->per_dir_config, &log_debug_module);
58    int i;
59    if (dconf->entries == NULL)
60        return;
61
62    for (i = 0; i < dconf->entries->nelts; i++) {
63        const char *msg, *err;
64        msg_entry *entry = APR_ARRAY_IDX(dconf->entries, i, msg_entry *);
65        if (entry->hook != allhooks && entry->hook != hookname)
66            continue;
67        if (entry->condition) {
68            int ret = ap_expr_exec(r, entry->condition, &err);
69            if (err) {
70                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00640)
71                              "Can't evaluate condition: %s", err);
72                continue;
73            }
74            if (!ret)
75                continue;
76        }
77        msg = ap_expr_str_exec(r, entry->msg_expr, &err);
78        if (err)
79            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00641)
80                          "Can't evaluate message expression: %s", err);
81        if (APLOGrdebug(r))
82            ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, "%s (%s hook, %s:%d)",
83                           msg, hookname, entry->msg_expr->filename,
84                           entry->msg_expr->line_number);
85        else
86            ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, "%s", msg);
87    }
88}
89
90static int log_debug_log_transaction(request_rec *r)
91{
92    do_debug_log(r, hooks[0]);
93    return DECLINED;
94}
95
96static int log_debug_quick_handler(request_rec *r, int lookup_uri)
97{
98    do_debug_log(r, hooks[1]);
99    return DECLINED;
100}
101
102static int log_debug_handler(request_rec *r)
103{
104    do_debug_log(r, hooks[2]);
105    return DECLINED;
106}
107
108static int log_debug_translate_name(request_rec *r)
109{
110    do_debug_log(r, hooks[3]);
111    return DECLINED;
112}
113
114static int log_debug_map_to_storage(request_rec *r)
115{
116    do_debug_log(r, hooks[4]);
117    return DECLINED;
118}
119
120static int log_debug_fixups(request_rec *r)
121{
122    do_debug_log(r, hooks[5]);
123    return DECLINED;
124}
125
126static int log_debug_type_checker(request_rec *r)
127{
128    do_debug_log(r, hooks[6]);
129    return DECLINED;
130}
131
132static int log_debug_check_access(request_rec *r)
133{
134    do_debug_log(r, hooks[7]);
135    return DECLINED;
136}
137
138static int log_debug_check_access_ex(request_rec *r)
139{
140    do_debug_log(r, hooks[8]);
141    return DECLINED;
142}
143
144static int log_debug_check_authn(request_rec *r)
145{
146    do_debug_log(r, hooks[9]);
147    return DECLINED;
148}
149
150static int log_debug_check_authz(request_rec *r)
151{
152    do_debug_log(r, hooks[10]);
153    return DECLINED;
154}
155
156static void log_debug_insert_filter(request_rec *r)
157{
158    do_debug_log(r, hooks[11]);
159}
160
161static void *log_debug_create_dconf(apr_pool_t *p, char *dirspec)
162{
163    log_debug_dirconf *dconf = apr_pcalloc(p, sizeof(log_debug_dirconf));
164    return dconf;
165}
166
167static void *log_debug_merge_dconf(apr_pool_t *p, void *parent_conf, void *new_conf)
168{
169    log_debug_dirconf *merged = apr_pcalloc(p, sizeof(log_debug_dirconf));
170    const log_debug_dirconf *parent = parent_conf;
171    const log_debug_dirconf *new = new_conf;
172
173    if (parent->entries == NULL)
174        merged->entries = new->entries;
175    else if (new->entries == NULL)
176        merged->entries = parent->entries;
177    else
178        /* apr_array_append actually creates a new array */
179        merged->entries = apr_array_append(p, parent->entries, new->entries);
180
181    return merged;
182}
183
184static const char *cmd_log_message(cmd_parms *cmd, void *dconf_, const char *arg1,
185                                   const char *arg2, const char *arg3)
186{
187    msg_entry *entry = apr_pcalloc(cmd->pool, sizeof(msg_entry));
188    log_debug_dirconf *dconf = dconf_;
189    int i, j;
190    const char *err;
191    const char *args[2];
192    args[0] = arg2;
193    args[1] = arg3;
194
195    entry->msg_expr = ap_expr_parse_cmd(cmd, arg1, AP_EXPR_FLAG_STRING_RESULT|
196                                                   AP_EXPR_FLAG_DONT_VARY,
197                                        &err, NULL);
198    if (err)
199        return apr_psprintf(cmd->pool,
200                            "Could not parse message expression '%s': %s",
201                            arg1, err);
202
203    for (i = 0; i < 2; i++) {
204        if (args[i] == NULL)
205            break;
206
207        if (strncasecmp(args[i], "hook=", 5) == 0) {
208            const char *name = args[i] + 5;
209            j = 0;
210            while (hooks[j]) {
211                if (strcasecmp(hooks[j], name) == 0) {
212                    entry->hook = hooks[j];
213                    break;
214                }
215                j++;
216            }
217            if (entry->hook == NULL) {
218                if (strcmp(name, "*") == 0 || strcasecmp(name, allhooks) == 0)
219                    entry->hook = allhooks;
220                else
221                    return apr_psprintf(cmd->pool, "Invalid hook name: %s", name);
222            }
223        }
224        else if (strncasecmp(args[i], "expr=", 5) == 0) {
225            const char *expr = args[i] + 5;
226            entry->condition = ap_expr_parse_cmd(cmd, expr,
227                                                 AP_EXPR_FLAG_DONT_VARY,
228                                                 &err, NULL);
229            if (err)
230                return apr_psprintf(cmd->pool,
231                                    "Could not parse expression '%s': %s",
232                                    expr, err);
233        }
234        else {
235            return apr_psprintf(cmd->pool, "Invalid argument %s", args[i]);
236        }
237    }
238    if (entry->hook == NULL)
239        entry->hook = hooks[0];
240
241    if (!dconf->entries)
242        dconf->entries = apr_array_make(cmd->pool, 4, sizeof(msg_entry *));
243
244    APR_ARRAY_PUSH(dconf->entries, msg_entry *) = entry;
245
246    return NULL;
247}
248
249static const command_rec log_debug_cmds[] =
250{
251    AP_INIT_TAKE123("LogMessage", cmd_log_message, NULL, RSRC_CONF|ACCESS_CONF,
252        "Log a debug message to the error log if this config block is used for "
253        " a request"),
254    {NULL}
255};
256
257static void register_hooks(apr_pool_t *p)
258{
259    ap_hook_log_transaction(log_debug_log_transaction, NULL, NULL, APR_HOOK_FIRST);
260    ap_hook_quick_handler(log_debug_quick_handler, NULL, NULL, APR_HOOK_FIRST);
261    ap_hook_handler(log_debug_handler, NULL, NULL, APR_HOOK_FIRST);
262    ap_hook_translate_name(log_debug_translate_name, NULL, NULL, APR_HOOK_FIRST);
263    ap_hook_map_to_storage(log_debug_map_to_storage, NULL, NULL, APR_HOOK_FIRST);
264    ap_hook_fixups(log_debug_fixups, NULL, NULL, APR_HOOK_FIRST);
265    ap_hook_type_checker(log_debug_type_checker, NULL, NULL, APR_HOOK_FIRST);
266    ap_hook_check_access(log_debug_check_access, NULL, NULL, APR_HOOK_FIRST, AP_AUTH_INTERNAL_PER_URI);
267    ap_hook_check_access_ex(log_debug_check_access_ex, NULL, NULL, APR_HOOK_FIRST, AP_AUTH_INTERNAL_PER_URI);
268    ap_hook_check_authn(log_debug_check_authn, NULL, NULL, APR_HOOK_FIRST, AP_AUTH_INTERNAL_PER_URI);
269    ap_hook_check_authz(log_debug_check_authz, NULL, NULL, APR_HOOK_FIRST, AP_AUTH_INTERNAL_PER_URI);
270    ap_hook_insert_filter(log_debug_insert_filter, NULL, NULL, APR_HOOK_FIRST);
271}
272
273AP_DECLARE_MODULE(log_debug) =
274{
275    STANDARD20_MODULE_STUFF,
276    log_debug_create_dconf,     /* create per-dir config */
277    log_debug_merge_dconf,      /* merge per-dir config */
278    NULL,                       /* server config */
279    NULL,                       /* merge server config */
280    log_debug_cmds,             /* command apr_table_t */
281    register_hooks              /* register hooks */
282};
283
284