Adding upstream version 2.4.58.upstream/2.4.58

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 711 insertions, 0 deletions

diff --git a/modules/session/mod_session.c b/modules/session/mod_session.c
new file mode 100644
index 0000000..fa8d406
--- /dev/null
+++ b/modules/session/mod_session.c
@@ -0,0 +1,711 @@
+/* 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 "mod_session.h"
+#include "apr_lib.h"
+#include "apr_strings.h"
+#include "util_filter.h"
+#include "http_log.h"
+#include "http_request.h"
+#include "http_protocol.h"
+
+#define SESSION_EXPIRY "expiry"
+#define HTTP_SESSION "HTTP_SESSION"
+
+APR_HOOK_STRUCT(
+                APR_HOOK_LINK(session_load)
+                APR_HOOK_LINK(session_save)
+                APR_HOOK_LINK(session_encode)
+                APR_HOOK_LINK(session_decode)
+)
+APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ap, SESSION, int, session_load,
+                      (request_rec * r, session_rec ** z), (r, z), DECLINED)
+APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ap, SESSION, int, session_save,
+                       (request_rec * r, session_rec * z), (r, z), DECLINED)
+APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, SESSION, int, session_encode,
+                   (request_rec * r, session_rec * z), (r, z), OK, DECLINED)
+APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, SESSION, int, session_decode,
+                   (request_rec * r, session_rec * z), (r, z), OK, DECLINED)
+
+static int session_identity_encode(request_rec * r, session_rec * z);
+static int session_identity_decode(request_rec * r, session_rec * z);
+static int session_fixups(request_rec * r);
+
+/**
+ * Should the session be included within this URL.
+ *
+ * This function tests whether a session is valid for this URL. It uses the
+ * include and exclude arrays to determine whether they should be included.
+ */
+static int session_included(request_rec * r, session_dir_conf * conf)
+{
+
+    const char **includes = (const char **) conf->includes->elts;
+    const char **excludes = (const char **) conf->excludes->elts;
+    int included = 1;                /* defaults to included */
+    int i;
+
+    if (conf->includes->nelts) {
+        included = 0;
+        for (i = 0; !included && i < conf->includes->nelts; i++) {
+            const char *include = includes[i];
+            if (strncmp(r->uri, include, strlen(include)) == 0) {
+                included = 1;
+            }
+        }
+    }
+
+    if (conf->excludes->nelts) {
+        for (i = 0; included && i < conf->excludes->nelts; i++) {
+            const char *exclude = excludes[i];
+            if (strncmp(r->uri, exclude, strlen(exclude)) == 0) {
+                included = 0;
+            }
+        }
+    }
+
+    return included;
+}
+
+/**
+ * Load the session.
+ *
+ * If the session doesn't exist, a blank one will be created.
+ *
+ * @param r The request
+ * @param z A pointer to where the session will be written.
+ */
+static apr_status_t ap_session_load(request_rec * r, session_rec ** z)
+{
+
+    session_dir_conf *dconf = ap_get_module_config(r->per_dir_config,
+                                                   &session_module);
+    apr_time_t now;
+    session_rec *zz = NULL;
+    int rv = 0;
+
+    /* is the session enabled? */
+    if (!dconf || !dconf->enabled) {
+        return APR_SUCCESS;
+    }
+
+    /* should the session be loaded at all? */
+    if (!session_included(r, dconf)) {
+        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01814)
+                      "excluded by configuration for: %s", r->uri);
+        return APR_SUCCESS;
+    }
+
+    /* load the session from the session hook */
+    rv = ap_run_session_load(r, &zz);
+    if (DECLINED == rv) {
+        ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01815)
+                      "session is enabled but no session modules have been configured, "
+                      "session not loaded: %s", r->uri);
+        return APR_EGENERAL;
+    }
+    else if (OK != rv) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01816)
+                      "error while loading the session, "
+                      "session not loaded: %s", r->uri);
+        return rv;
+    }
+
+    /* found a session that hasn't expired? */
+    now = apr_time_now();
+
+    if (zz) {
+        /* load the session attributes */
+        rv = ap_run_session_decode(r, zz);
+ 
+        /* having a session we cannot decode is just as good as having
+           none at all */
+       if (OK != rv) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01817)
+                    "error while decoding the session, "
+                    "session not loaded: %s", r->uri);
+            zz = NULL;
+        }
+
+       /* invalidate session if session is expired */
+        if (zz && zz->expiry && zz->expiry < now) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "session is expired");
+            zz = NULL;
+        }
+    }
+
+    /* no luck, create a blank session */
+    if (!zz) {
+        zz = (session_rec *) apr_pcalloc(r->pool, sizeof(session_rec));
+        zz->pool = r->pool;
+        zz->entries = apr_table_make(zz->pool, 10);
+    }
+
+    /* make sure the expiry and maxage are set, if present */
+    if (dconf->maxage) {
+        if (!zz->expiry) {
+            zz->expiry = now + dconf->maxage * APR_USEC_PER_SEC;
+        }
+        zz->maxage = dconf->maxage;
+    }
+
+    *z = zz;
+
+    return APR_SUCCESS;
+
+}
+
+/**
+ * Save the session.
+ *
+ * In most implementations the session is only saved if the dirty flag is
+ * true. This prevents the session being saved unnecessarily.
+ *
+ * @param r The request
+ * @param z A pointer to where the session will be written.
+ */
+static apr_status_t ap_session_save(request_rec * r, session_rec * z)
+{
+    if (z) {
+        apr_time_t now = apr_time_now();
+        apr_time_t initialExpiry = z->expiry;
+        int rv = 0;
+
+        session_dir_conf *dconf = ap_get_module_config(r->per_dir_config,
+                                                       &session_module);
+
+        /* sanity checks, should we try save at all? */
+        if (z->written) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01818)
+                          "attempt made to save the session twice, "
+                          "session not saved: %s", r->uri);
+            return APR_EGENERAL;
+        }
+        if (z->expiry && z->expiry < now) {
+            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01819)
+                          "attempt made to save a session when the session had already expired, "
+                          "session not saved: %s", r->uri);
+            return APR_EGENERAL;
+        }
+
+        /* reset the expiry back to maxage, if the expiry is present */
+        if (dconf->maxage) {
+            z->expiry = now + dconf->maxage * APR_USEC_PER_SEC;
+            z->maxage = dconf->maxage;
+        }
+
+        /* reset the expiry before saving if present */
+        if (z->dirty && z->maxage) {
+            z->expiry = now + z->maxage * APR_USEC_PER_SEC;
+        } 
+
+        /* don't save if the only change is the expiry by a small amount */
+        if (!z->dirty && dconf->expiry_update_time
+                && (z->expiry - initialExpiry < dconf->expiry_update_time)) {
+            return APR_SUCCESS;
+        }
+
+        /* also don't save sessions that didn't change at all */
+        if (!z->dirty && !z->maxage) {
+            return APR_SUCCESS;
+        }
+
+        /* encode the session */
+        rv = ap_run_session_encode(r, z);
+        if (OK != rv) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01820)
+                          "error while encoding the session, "
+                          "session not saved: %s", r->uri);
+            return rv;
+        }
+
+        /* try the save */
+        rv = ap_run_session_save(r, z);
+        if (DECLINED == rv) {
+            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01821)
+                          "session is enabled but no session modules have been configured, "
+                          "session not saved: %s", r->uri);
+            return APR_EGENERAL;
+        }
+        else if (OK != rv) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01822)
+                          "error while saving the session, "
+                          "session not saved: %s", r->uri);
+            return rv;
+        }
+        else {
+            z->written = 1;
+        }
+    }
+
+    return APR_SUCCESS;
+
+}
+
+/**
+ * Get a particular value from the session.
+ * @param r The current request.
+ * @param z The current session. If this value is NULL, the session will be
+ * looked up in the request, created if necessary, and saved to the request
+ * notes.
+ * @param key The key to get.
+ * @param value The buffer to write the value to.
+ */
+static apr_status_t ap_session_get(request_rec * r, session_rec * z,
+        const char *key, const char **value)
+{
+    if (!z) {
+        apr_status_t rv;
+        rv = ap_session_load(r, &z);
+        if (APR_SUCCESS != rv) {
+            return rv;
+        }
+    }
+    if (z && z->entries) {
+        *value = apr_table_get(z->entries, key);
+    }
+
+    return OK;
+}
+
+/**
+ * Set a particular value to the session.
+ *
+ * Using this method ensures that the dirty flag is set correctly, so that
+ * the session can be saved efficiently.
+ * @param r The current request.
+ * @param z The current session. If this value is NULL, the session will be
+ * looked up in the request, created if necessary, and saved to the request
+ * notes.
+ * @param key The key to set. The existing key value will be replaced.
+ * @param value The value to set.
+ */
+static apr_status_t ap_session_set(request_rec * r, session_rec * z,
+        const char *key, const char *value)
+{
+    if (!z) {
+        apr_status_t rv;
+        rv = ap_session_load(r, &z);
+        if (APR_SUCCESS != rv) {
+            return rv;
+        }
+    }
+    if (z) {
+        if (value) {
+            apr_table_set(z->entries, key, value);
+        }
+        else {
+            apr_table_unset(z->entries, key);
+        }
+        z->dirty = 1;
+    }
+    return APR_SUCCESS;
+}
+
+static int identity_count(void *v, const char *key, const char *val)
+{
+    apr_size_t *count = v;
+
+    *count += strlen(key) * 3 + strlen(val) * 3 + 2;
+    return 1;
+}
+
+static int identity_concat(void *v, const char *key, const char *val)
+{
+    char *slider = v;
+    apr_size_t length = strlen(slider);
+
+    slider += length;
+    if (length) {
+        *slider = '&';
+        slider++;
+    }
+    ap_escape_urlencoded_buffer(slider, key);
+    slider += strlen(slider);
+    *slider = '=';
+    slider++;
+    ap_escape_urlencoded_buffer(slider, val);
+    return 1;
+}
+
+/**
+ * Default identity encoding for the session.
+ *
+ * By default, the name value pairs in the session are URLEncoded, separated
+ * by equals, and then in turn separated by ampersand, in the format of an
+ * html form.
+ *
+ * This was chosen to make it easy for external code to unpack a session,
+ * should there be a need to do so.
+ *
+ * @param r The request pointer.
+ * @param z A pointer to where the session will be written.
+ */
+static apr_status_t session_identity_encode(request_rec * r, session_rec * z)
+{
+    char *buffer = NULL;
+    apr_size_t length = 0;
+
+    if (z->expiry) {
+        char *expiry = apr_psprintf(z->pool, "%" APR_INT64_T_FMT, z->expiry);
+        apr_table_setn(z->entries, SESSION_EXPIRY, expiry);
+    }
+    apr_table_do(identity_count, &length, z->entries, NULL);
+    buffer = apr_pcalloc(r->pool, length + 1);
+    apr_table_do(identity_concat, buffer, z->entries, NULL);
+    z->encoded = buffer;
+    return OK;
+
+}
+
+/**
+ * Default identity decoding for the session.
+ *
+ * By default, the name value pairs in the session are URLEncoded, separated
+ * by equals, and then in turn separated by ampersand, in the format of an
+ * html form.
+ *
+ * This was chosen to make it easy for external code to unpack a session,
+ * should there be a need to do so.
+ *
+ * This function reverses that process, and populates the session table.
+ *
+ * Name / value pairs that are not encoded properly are ignored.
+ *
+ * @param r The request pointer.
+ * @param z A pointer to where the session will be written.
+ */
+static apr_status_t session_identity_decode(request_rec * r, session_rec * z)
+{
+
+    char *last = NULL;
+    char *encoded, *pair;
+    const char *sep = "&";
+
+    /* sanity check - anything to decode? */
+    if (!z->encoded) {
+        return OK;
+    }
+
+    /* decode what we have */
+    encoded = apr_pstrdup(r->pool, z->encoded);
+    pair = apr_strtok(encoded, sep, &last);
+    while (pair && pair[0]) {
+        char *plast = NULL;
+        const char *psep = "=";
+        char *key = apr_strtok(pair, psep, &plast);
+        if (key && *key) {
+            char *val = apr_strtok(NULL, sep, &plast);
+            if (!val || !*val) {
+                apr_table_unset(z->entries, key);
+            }
+            else if (!ap_unescape_urlencoded(key) && !ap_unescape_urlencoded(val)) {
+                if (!strcmp(SESSION_EXPIRY, key)) {
+                    z->expiry = (apr_time_t) apr_atoi64(val);
+                }
+                else {
+                    apr_table_set(z->entries, key, val);
+                }
+            }
+        }
+        pair = apr_strtok(NULL, sep, &last);
+    }
+    z->encoded = NULL;
+    return OK;
+
+}
+
+/**
+ * Ensure any changes to the session are committed.
+ *
+ * This is done in an output filter so that our options for where to
+ * store the session can include storing the session within a cookie:
+ * As an HTTP header, the cookie must be set before the output is
+ * written, but after the handler is run.
+ *
+ * NOTE: It is possible for internal redirects to cause more than one
+ * request to be present, and each request might have a session
+ * defined. We need to go through each session in turn, and save each
+ * one.
+ *
+ * The same session might appear in more than one request. The first
+ * attempt to save the session will be called
+ */
+static apr_status_t session_output_filter(ap_filter_t * f,
+        apr_bucket_brigade * in)
+{
+
+    /* save all the sessions in all the requests */
+    request_rec *r = f->r->main;
+    if (!r) {
+        r = f->r;
+    }
+    while (r) {
+        session_rec *z = NULL;
+        session_dir_conf *conf = ap_get_module_config(r->per_dir_config,
+                                                      &session_module);
+
+        /* load the session, or create one if necessary */
+        /* when unset or on error, z will be NULL */
+        ap_session_load(r, &z);
+        if (!z || z->written) {
+            r = r->next;
+            continue;
+        }
+
+        /* if a header was specified, insert the new values from the header */
+        if (conf->header_set) {
+            const char *override = apr_table_get(r->err_headers_out, conf->header);
+            if (!override) {
+                override = apr_table_get(r->headers_out, conf->header);
+            }
+            if (override) {
+                apr_table_unset(r->err_headers_out, conf->header);
+                apr_table_unset(r->headers_out, conf->header);
+                z->encoded = override;
+                z->dirty = 1;
+                session_identity_decode(r, z);
+            }
+        }
+
+        /* save away the session, and we're done */
+        /* when unset or on error, we've complained to the log */
+        ap_session_save(r, z);
+
+        r = r->next;
+    }
+
+    /* remove ourselves from the filter chain */
+    ap_remove_output_filter(f);
+
+    /* send the data up the stack */
+    return ap_pass_brigade(f->next, in);
+
+}
+
+/**
+ * Insert the output filter.
+ */
+static void session_insert_output_filter(request_rec * r)
+{
+    ap_add_output_filter("MOD_SESSION_OUT", NULL, r, r->connection);
+}
+
+/**
+ * Fixups hook.
+ *
+ * Load the session within a fixup - this ensures that the session is
+ * properly loaded prior to the handler being called.
+ *
+ * The fixup is also responsible for injecting the session into the CGI
+ * environment, should the admin have configured it so.
+ *
+ * @param r The request
+ */
+static int session_fixups(request_rec * r)
+{
+    session_dir_conf *conf = ap_get_module_config(r->per_dir_config,
+                                                  &session_module);
+
+    session_rec *z = NULL;
+
+    /* if an error occurs or no session has been configured, we ignore
+     * the broken session and allow it to be recreated from scratch on save
+     * if necessary.
+     */
+    ap_session_load(r, &z);
+
+    if (conf->env) {
+        if (z) {
+            session_identity_encode(r, z);
+            if (z->encoded) {
+                apr_table_set(r->subprocess_env, HTTP_SESSION, z->encoded);
+                z->encoded = NULL;
+            }
+        }
+        apr_table_unset(r->headers_in, "Session");
+    }
+
+    return OK;
+
+}
+
+
+static void *create_session_dir_config(apr_pool_t * p, char *dummy)
+{
+    session_dir_conf *new =
+    (session_dir_conf *) apr_pcalloc(p, sizeof(session_dir_conf));
+
+    new->includes = apr_array_make(p, 10, sizeof(const char **));
+    new->excludes = apr_array_make(p, 10, sizeof(const char **));
+
+    return (void *) new;
+}
+
+static void *merge_session_dir_config(apr_pool_t * p, void *basev, void *addv)
+{
+    session_dir_conf *new = (session_dir_conf *) apr_pcalloc(p, sizeof(session_dir_conf));
+    session_dir_conf *add = (session_dir_conf *) addv;
+    session_dir_conf *base = (session_dir_conf *) basev;
+
+    new->enabled = (add->enabled_set == 0) ? base->enabled : add->enabled;
+    new->enabled_set = add->enabled_set || base->enabled_set;
+    new->maxage = (add->maxage_set == 0) ? base->maxage : add->maxage;
+    new->maxage_set = add->maxage_set || base->maxage_set;
+    new->header = (add->header_set == 0) ? base->header : add->header;
+    new->header_set = add->header_set || base->header_set;
+    new->env = (add->env_set == 0) ? base->env : add->env;
+    new->env_set = add->env_set || base->env_set;
+    new->includes = apr_array_append(p, base->includes, add->includes);
+    new->excludes = apr_array_append(p, base->excludes, add->excludes);
+    new->expiry_update_time = (add->expiry_update_set == 0)
+                                ? base->expiry_update_time
+                                : add->expiry_update_time;
+    new->expiry_update_set = add->expiry_update_set || base->expiry_update_set;
+
+    return new;
+}
+
+
+static const char *
+     set_session_enable(cmd_parms * parms, void *dconf, int flag)
+{
+    session_dir_conf *conf = dconf;
+
+    conf->enabled = flag;
+    conf->enabled_set = 1;
+
+    return NULL;
+}
+
+static const char *
+     set_session_maxage(cmd_parms * parms, void *dconf, const char *arg)
+{
+    session_dir_conf *conf = dconf;
+
+    conf->maxage = atol(arg);
+    conf->maxage_set = 1;
+
+    return NULL;
+}
+
+static const char *
+     set_session_header(cmd_parms * parms, void *dconf, const char *arg)
+{
+    session_dir_conf *conf = dconf;
+
+    conf->header = arg;
+    conf->header_set = 1;
+
+    return NULL;
+}
+
+static const char *
+     set_session_env(cmd_parms * parms, void *dconf, int flag)
+{
+    session_dir_conf *conf = dconf;
+
+    conf->env = flag;
+    conf->env_set = 1;
+
+    return NULL;
+}
+
+static const char *add_session_include(cmd_parms * cmd, void *dconf, const char *f)
+{
+    session_dir_conf *conf = dconf;
+
+    const char **new = apr_array_push(conf->includes);
+    *new = f;
+
+    return NULL;
+}
+
+static const char *add_session_exclude(cmd_parms * cmd, void *dconf, const char *f)
+{
+    session_dir_conf *conf = dconf;
+
+    const char **new = apr_array_push(conf->excludes);
+    *new = f;
+
+    return NULL;
+}
+
+static const char *
+     set_session_expiry_update(cmd_parms * parms, void *dconf, const char *arg)
+{
+    session_dir_conf *conf = dconf;
+
+    conf->expiry_update_time = atoi(arg);
+    if (conf->expiry_update_time < 0) {
+        return "SessionExpiryUpdateInterval must be zero (disable) or a positive value";
+    }
+    conf->expiry_update_time = apr_time_from_sec(conf->expiry_update_time);
+    conf->expiry_update_set = 1;
+
+    return NULL;
+}
+
+
+static const command_rec session_cmds[] =
+{
+    AP_INIT_FLAG("Session", set_session_enable, NULL, RSRC_CONF|OR_AUTHCFG,
+                 "on if a session should be maintained for these URLs"),
+    AP_INIT_TAKE1("SessionMaxAge", set_session_maxage, NULL, RSRC_CONF|OR_AUTHCFG,
+                  "length of time for which a session should be valid. Zero to disable"),
+    AP_INIT_TAKE1("SessionHeader", set_session_header, NULL, RSRC_CONF|OR_AUTHCFG,
+                  "output header, if present, whose contents will be injected into the session."),
+    AP_INIT_FLAG("SessionEnv", set_session_env, NULL, RSRC_CONF|OR_AUTHCFG,
+                 "on if a session should be written to the CGI environment. Defaults to off"),
+    AP_INIT_TAKE1("SessionInclude", add_session_include, NULL, RSRC_CONF|OR_AUTHCFG,
+                  "URL prefixes to include in the session. Defaults to all URLs"),
+    AP_INIT_TAKE1("SessionExclude", add_session_exclude, NULL, RSRC_CONF|OR_AUTHCFG,
+                  "URL prefixes to exclude from the session. Defaults to no URLs"),
+    AP_INIT_TAKE1("SessionExpiryUpdateInterval", set_session_expiry_update, NULL, RSRC_CONF|OR_AUTHCFG,
+                  "time interval for which a session's expiry time may change "
+                  "without having to be rewritten. Zero to disable"),
+    {NULL}
+};
+
+static void register_hooks(apr_pool_t * p)
+{
+    ap_register_output_filter("MOD_SESSION_OUT", session_output_filter,
+                              NULL, AP_FTYPE_CONTENT_SET);
+    ap_hook_insert_filter(session_insert_output_filter, NULL, NULL,
+                          APR_HOOK_MIDDLE);
+    ap_hook_insert_error_filter(session_insert_output_filter,
+                                NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_fixups(session_fixups, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_session_encode(session_identity_encode, NULL, NULL,
+                           APR_HOOK_REALLY_FIRST);
+    ap_hook_session_decode(session_identity_decode, NULL, NULL,
+                           APR_HOOK_REALLY_LAST);
+    APR_REGISTER_OPTIONAL_FN(ap_session_get);
+    APR_REGISTER_OPTIONAL_FN(ap_session_set);
+    APR_REGISTER_OPTIONAL_FN(ap_session_load);
+    APR_REGISTER_OPTIONAL_FN(ap_session_save);
+}
+
+AP_DECLARE_MODULE(session) =
+{
+    STANDARD20_MODULE_STUFF,
+    create_session_dir_config,   /* dir config creater */
+    merge_session_dir_config,    /* dir merger --- default is to override */
+    NULL,                        /* server config */
+    NULL,                        /* merge server config */
+    session_cmds,                /* command apr_table_t */
+    register_hooks               /* register hooks */
+};