working support for a ssl session cache via memcached.

1 files changed, 186 insertions, 20 deletions

diff --git a/src/gnutls_cache.c b/src/gnutls_cache.c
index 683cdf4..bc13440 100644
--- a/src/gnutls_cache.c
+++ b/src/gnutls_cache.c
@@ -16,46 +16,212 @@
  */
 
 #include "mod_gnutls.h"
+#include "ap_mpm.h"
 
 /**
  * GnuTLS Session Cache using libmemcached
  *
  */
-/*
-#include "memcache.h"
 
-int mod_gnutls_cache_init()
+/* The underlying apr_memcache system is thread safe... woohoo */
+static apr_memcache_t* mc;
+
+int mod_gnutls_cache_child_init(apr_pool_t *p, server_rec *s, 
+                                mod_gnutls_srvconf_rec *sc)
 {
-  return 0;
+    apr_status_t rv = APR_SUCCESS;
+    int thread_limit = 0;
+    int nservers = 0;
+    char* cache_config;
+    char* split;
+    char* tok;
+
+    ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &thread_limit);
+
+    /* Find all the servers in the first run to get a total count */
+    cache_config = apr_pstrdup(p, sc->cache_config);
+    split = apr_strtok(cache_config, " ", &tok);
+    while (split) {
+        nservers++;
+        split = apr_strtok(NULL," ", &tok);
+    }
+
+    rv = apr_memcache_create(p, nservers, 0, &mc);
+    if (rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s,
+                        "[gnutls_cache] Failed to create Memcache Object of '%d' size.", 
+                         nservers);
+        return rv;
+    }
+
+    /* Now add each server to the memcache */
+    cache_config = apr_pstrdup(p, sc->cache_config);
+    split = apr_strtok(cache_config, " ", &tok);
+    while (split) {
+        apr_memcache_server_t* st;
+        char* split2;
+        char* host_str;
+        char* port_str;
+        int port;
+
+        host_str = apr_strtok(split,":", &split2);
+        port_str = apr_strtok(NULL,":", &split2);
+        if (!port_str) {
+            port = 11211; /* default port */
+        }
+        else {
+            port = atoi(port_str);
+        }
+
+        /* Should Max Conns be (thread_limit / nservers) ? */
+        rv = apr_memcache_server_create(p,
+                                        host_str, port,
+                                        0,
+                                        1,
+                                        thread_limit, 
+                                        600,
+                                        &st);
+        if(rv != APR_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s,
+                         "[gnutls_cache] Failed to Create Server: %s:%d", 
+                         host_str, port);
+            return rv;
+        }
+
+        rv = apr_memcache_add_server(mc, st);
+        if(rv != APR_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s,
+                         "[gnutls_cache] Failed to Add Server: %s:%d", 
+                         host_str, port);
+            return rv;
+        }
+
+        split = apr_strtok(NULL," ", &tok);
+    }
+    return rv;
 }
-static int cache_store((void* baton, gnutls_datum_t key, gnutls_datum_t data)
+
+/* thanks mod_ssl */
+#define GNUTLS_SESSION_ID_STRING_LEN \
+    ((GNUTLS_MAX_SESSION_ID + 1) * 2)
+#define MC_TAG "mod_gnutls:"
+#define MC_TAG_LEN \
+    (sizeof(MC_TAG))
+#define STR_SESSION_LEN (GNUTLS_SESSION_ID_STRING_LEN + MC_TAG_LEN)
+
+
+static char *gnutls_session_id2sz(unsigned char *id, int idlen,
+                        char *str, int strsize)
 {
-    mc_set(struct memcache *mc,
-           key->data, key->size,
-           data->data, data->size, 
-           3600, 0);
-  return 0;
+    char *cp;
+    int n;
+ 
+    cp = apr_cpystrn(str, MC_TAG, MC_TAG_LEN);
+    for (n = 0; n < idlen && n < GNUTLS_MAX_SESSION_ID; n++) {
+        apr_snprintf(cp, strsize - (cp-str), "%02X", id[n]);
+        cp += 2;
+    }
+    *cp = '\0';
+    return str;
 }
 
-static int cache_fetch(void* baton, gnutls_datum_t key)
+
+static int cache_store(void* baton, gnutls_datum_t key, gnutls_datum_t data)
 {
+    apr_status_t rv = APR_SUCCESS;
     mod_gnutls_handle_t *ctxt = baton;
-  return 0;
+    char buf[STR_SESSION_LEN];
+    char* strkey = NULL;
+    apr_uint32_t timeout;
+
+    strkey = gnutls_session_id2sz(key.data, key.size, buf, sizeof(buf));
+    if(!strkey)
+        return -1;
+
+    timeout = 3600;
+
+    rv = apr_memcache_set(mc,  strkey, data.data, data.size, timeout, 0);
+
+    if(rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, rv,
+                     ctxt->c->base_server,
+                     "[gnutls_cache] error setting key '%s' "
+                     "with %d bytes of data", strkey, data.size);
+        return -1;
+    }
+
+    return 0;
+}
+
+static gnutls_datum_t cache_fetch(void* baton, gnutls_datum_t key)
+{
+    apr_status_t rv = APR_SUCCESS;
+    mod_gnutls_handle_t *ctxt = baton;
+    char buf[STR_SESSION_LEN];
+    char* strkey = NULL;
+    char* value;
+    apr_size_t value_len;
+    gnutls_datum_t data = { NULL, 0 };
+
+    strkey = gnutls_session_id2sz(key.data, key.size, buf, sizeof(buf));
+    if(!strkey) {
+        return data;
+    }
+
+    rv = apr_memcache_getp(mc, ctxt->c->pool, strkey,
+                           &value, &value_len, NULL);
+
+    if(rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_DEBUG, rv,
+                     ctxt->c->base_server,
+                     "[gnutls_cache] error fetching key '%s' ",
+                     strkey);
+
+        data.size = 0;
+        data.data = NULL;
+        return data;
+    }
+
+    /* TODO: Eliminate this memcpy. ffs. gnutls-- */
+    data.data = gnutls_malloc(value_len);
+    if (data.data == NULL)
+        return data;
+
+    data.size = value_len;
+    memcpy(data.data, value, value_len);
+
+    return data;
 }
 
 static int cache_delete(void* baton, gnutls_datum_t key)
 {
+    apr_status_t rv = APR_SUCCESS;
     mod_gnutls_handle_t *ctxt = baton;
-  return 0;
+    char buf[STR_SESSION_LEN];
+    char* strkey = NULL;
+
+    strkey = gnutls_session_id2sz(key.data, key.size, buf, sizeof(buf));
+    if(!strkey)
+        return -1;
+
+    rv = apr_memcache_delete(mc, strkey, 0);
+
+    if(rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_DEBUG, rv,
+                     ctxt->c->base_server,
+                     "[gnutls_cache] error deleting key '%s' ",
+                      strkey);
+        return -1;
+    }
+
+    return 0;
 }
 
 int mod_gnutls_cache_session_init(mod_gnutls_handle_t *ctxt)
 {
-    gnutls_db_set_cache_expiration
-    gnutls_db_set_retrieve_function(session, cache_fetch);
-    gnutls_db_set_remove_function(session, cache_delete);
-    gnutls_db_set_store_function(session, cache_store);
-    gnutls_db_set_ptr(session, NULL);
-  return 0;
+    gnutls_db_set_retrieve_function(ctxt->session, cache_fetch);
+    gnutls_db_set_remove_function(ctxt->session, cache_delete);
+    gnutls_db_set_store_function(ctxt->session, cache_store);
+    gnutls_db_set_ptr(ctxt->session, ctxt);
+    return 0;
 }
-*/