fixing common off-by-one error with respect to maximum message size

22 files changed, 59 insertions, 52 deletions

diff --git a/src/arm/arm_api.c b/src/arm/arm_api.c
index 6c2b53a71..0726f7e66 100644
--- a/src/arm/arm_api.c
+++ b/src/arm/arm_api.c
@@ -541,8 +541,7 @@ change_service (struct GNUNET_ARM_Handle *h,
   struct GNUNET_MessageHeader *msg;
 
   slen = strlen (service_name) + 1;
-  if (slen + sizeof (struct GNUNET_MessageHeader) >
-      GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (slen + sizeof (struct GNUNET_MessageHeader) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
     {
       GNUNET_break (0);
       if (cb != NULL)
diff --git a/src/core/gnunet-service-core.c b/src/core/gnunet-service-core.c
index a181ae5bb..5a223d70b 100644
--- a/src/core/gnunet-service-core.c
+++ b/src/core/gnunet-service-core.c
@@ -1717,7 +1717,7 @@ batch_message (struct Neighbour *n,
                struct GNUNET_TIME_Relative *retry_time,
                unsigned int *priority)
 {
-  char ntmb[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char ntmb[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   struct NotifyTrafficMessage *ntm = (struct NotifyTrafficMessage*) ntmb;
   struct MessageEntry *pos;
   struct MessageEntry *prev;
@@ -3824,7 +3824,7 @@ run (void *cls,
                                         &handle_transport_notify_disconnect);
   GNUNET_assert (NULL != transport);
   stats = GNUNET_STATISTICS_create (sched, "core", cfg);
-  mst = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE,
+  mst = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                                   &deliver_message,
                                   NULL);
   GNUNET_SCHEDULER_add_delayed (sched,
diff --git a/src/datastore/datastore_api.c b/src/datastore/datastore_api.c
index 2218fffc3..1344eaeff 100644
--- a/src/datastore/datastore_api.c
+++ b/src/datastore/datastore_api.c
@@ -245,7 +245,7 @@ GNUNET_DATASTORE_connect (const struct
   if (c == NULL)
     return NULL; /* oops */
   h = GNUNET_malloc (sizeof(struct GNUNET_DATASTORE_Handle) + 
-                     GNUNET_SERVER_MAX_MESSAGE_SIZE);
+                     GNUNET_SERVER_MAX_MESSAGE_SIZE - 1);
   h->client = c;
   h->cfg = cfg;
   h->sched = sched;
@@ -790,7 +790,7 @@ GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
               GNUNET_h2s (key));
 #endif
   msize = sizeof(struct DataMessage) + size;
-  GNUNET_assert (msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE);
+  GNUNET_assert (msize < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   qc.sc.cont = cont;
   qc.sc.cont_cls = cont_cls;
   qe = make_queue_entry (h, msize,
@@ -1037,7 +1037,7 @@ GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
   qc.sc.cont = cont;
   qc.sc.cont_cls = cont_cls;
   msize = sizeof(struct DataMessage) + size;
-  GNUNET_assert (msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE);
+  GNUNET_assert (msize < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   qe = make_queue_entry (h, msize,
                          queue_priority, max_queue_size, timeout,
                          &process_status_message, &qc);
diff --git a/src/dv/gnunet-service-dv.c b/src/dv/gnunet-service-dv.c
index 8366348d5..6ef4e82fe 100644
--- a/src/dv/gnunet-service-dv.c
+++ b/src/dv/gnunet-service-dv.c
@@ -3002,7 +3002,7 @@ run (void *cls,
   if (coreAPI == NULL)
     return;
 
-  coreMST = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE,
+  coreMST = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                                       &tokenized_message_handler,
                                       NULL);
 
diff --git a/src/fs/fs_publish.c b/src/fs/fs_publish.c
index 2ebb96169..13701405e 100644
--- a/src/fs/fs_publish.c
+++ b/src/fs/fs_publish.c
@@ -761,7 +761,7 @@ hash_for_index_cb (void *cls,
   fn = GNUNET_STRINGS_filename_expand (p->filename);
   GNUNET_assert (fn != NULL);
   slen = strlen (fn) + 1;
-  if (slen > GNUNET_SERVER_MAX_MESSAGE_SIZE - sizeof(struct IndexStartMessage))
+  if (slen >= GNUNET_SERVER_MAX_MESSAGE_SIZE - sizeof(struct IndexStartMessage))
     {
       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                   _("Can not index file `%s': %s.  Will try to insert instead.\n"),
diff --git a/src/fs/gnunet-service-fs_indexing.c b/src/fs/gnunet-service-fs_indexing.c
index d6654bcdc..b72c53fc0 100644
--- a/src/fs/gnunet-service-fs_indexing.c
+++ b/src/fs/gnunet-service-fs_indexing.c
@@ -430,7 +430,7 @@ GNUNET_FS_handle_index_list_get (void *cls,
 {
   struct GNUNET_SERVER_TransmitContext *tc;
   struct IndexInfoMessage *iim;
-  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   size_t slen;
   const char *fn;
   struct IndexInfo *pos;
@@ -442,8 +442,7 @@ GNUNET_FS_handle_index_list_get (void *cls,
     {
       fn = pos->filename;
       slen = strlen (fn) + 1;
-      if (slen + sizeof (struct IndexInfoMessage) > 
-          GNUNET_SERVER_MAX_MESSAGE_SIZE)
+      if (slen + sizeof (struct IndexInfoMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
         {
           GNUNET_break (0);
           break;
diff --git a/src/hello/hello.c b/src/hello/hello.c
index abcc25c71..f41a601fd 100644
--- a/src/hello/hello.c
+++ b/src/hello/hello.c
@@ -167,7 +167,7 @@ GNUNET_HELLO_create (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
                      GNUNET_HELLO_GenerateAddressListCallback addrgen,
                      void *addrgen_cls)
 {
-  char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 256 -
+  char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - 256 -
               sizeof (struct GNUNET_HELLO_Message)];
   size_t max;
   size_t used;
diff --git a/src/hostlist/hostlist-client.c b/src/hostlist/hostlist-client.c
index ff8ab2e9a..b6514984d 100644
--- a/src/hostlist/hostlist-client.c
+++ b/src/hostlist/hostlist-client.c
@@ -272,7 +272,7 @@ callback_download (void *ptr,
                              size_t nmemb, 
                              void *ctx)
 {
-  static char download_buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  static char download_buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   const char * cbuf = ptr;
   const struct GNUNET_MessageHeader *msg;
   size_t total;
@@ -295,7 +295,7 @@ callback_download (void *ptr,
   while ( (left > 0) ||
           (download_pos > 0) )
     {
-      cpy = GNUNET_MIN (left, GNUNET_SERVER_MAX_MESSAGE_SIZE - download_pos);
+      cpy = GNUNET_MIN (left, GNUNET_SERVER_MAX_MESSAGE_SIZE - 1 - download_pos);
       memcpy (&download_buffer[download_pos],
               cbuf,
               cpy);      
diff --git a/src/hostlist/hostlist-server.c b/src/hostlist/hostlist-server.c
index 0726bf3e0..014c0f41f 100644
--- a/src/hostlist/hostlist-server.c
+++ b/src/hostlist/hostlist-server.c
@@ -399,7 +399,7 @@ connect_handler (void *cls,
   if (hostlist_uri == NULL)
     return;
   size = strlen (hostlist_uri) + 1;
-  if (size + sizeof (struct GNUNET_MessageHeader) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (size + sizeof (struct GNUNET_MessageHeader) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
     {
       GNUNET_break (0);
       return;
diff --git a/src/peerinfo/gnunet-service-peerinfo.c b/src/peerinfo/gnunet-service-peerinfo.c
index ae8a0dfe3..a839da049 100644
--- a/src/peerinfo/gnunet-service-peerinfo.c
+++ b/src/peerinfo/gnunet-service-peerinfo.c
@@ -249,7 +249,7 @@ add_host_to_known_hosts (const struct GNUNET_PeerIdentity *identity)
   struct HostEntry *entry;
   char *fn;
   uint32_t trust;
-  char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   const struct GNUNET_HELLO_Message *hello;
   struct GNUNET_HELLO_Message *hello_clean;
   int size;
@@ -494,7 +494,7 @@ send_to_each_host (const struct GNUNET_PeerIdentity *only,
   struct HostEntry *pos;
   struct InfoMessage *im;
   uint16_t hs;
-  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   struct GNUNET_SERVER_TransmitContext *tc;
   int match;
 
@@ -600,7 +600,7 @@ static int
 discard_hosts_helper (void *cls, const char *fn)
 {
   struct GNUNET_TIME_Absolute *now = cls;
-  char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   const struct GNUNET_HELLO_Message *hello;
   struct GNUNET_HELLO_Message *new_hello;
   int size;
diff --git a/src/topology/gnunet-daemon-topology.c b/src/topology/gnunet-daemon-topology.c
index 970045093..1c58b5210 100644
--- a/src/topology/gnunet-daemon-topology.c
+++ b/src/topology/gnunet-daemon-topology.c
@@ -629,7 +629,7 @@ schedule_next_hello (void *cls,
   /* find applicable HELLOs */
   fah.peer = pl;
   fah.result = NULL;
-  fah.max_size = GNUNET_SERVER_MAX_MESSAGE_SIZE;
+  fah.max_size = GNUNET_SERVER_MAX_MESSAGE_SIZE - 1;
   fah.next_adv = GNUNET_TIME_UNIT_FOREVER_REL;
   GNUNET_CONTAINER_multihashmap_iterate (peers,
                                          &find_advertisable_hello,
diff --git a/src/transport/plugin_transport_http.c b/src/transport/plugin_transport_http.c
index 5946105ac..f512d3580 100644
--- a/src/transport/plugin_transport_http.c
+++ b/src/transport/plugin_transport_http.c
@@ -541,7 +541,7 @@ accessHandlerCallback (void *cls,
       }
       */
       if (cs->msgtok==NULL)
-        cs->msgtok = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE, &messageTokenizerCallback, cs);
+        cs->msgtok = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1, &messageTokenizerCallback, cs);
     }
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,"HTTP Daemon has new an incoming `%s' request from peer `%s'\n",method, GNUNET_i2s(&cs->identity));
   }
@@ -570,7 +570,7 @@ accessHandlerCallback (void *cls,
 
     if ((*upload_data_size > 0) && (cs->is_bad_request != GNUNET_YES))
     {
-      if (*upload_data_size + cs->pending_inbound_msg.bytes_recv <= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+      if (*upload_data_size + cs->pending_inbound_msg.bytes_recv < GNUNET_SERVER_MAX_MESSAGE_SIZE)
       {
         /* copy uploaded data to buffer */
 
diff --git a/src/transport/plugin_transport_tcp.c b/src/transport/plugin_transport_tcp.c
index 9b09d8948..c1397da61 100644
--- a/src/transport/plugin_transport_tcp.c
+++ b/src/transport/plugin_transport_tcp.c
@@ -1120,7 +1120,7 @@ tcp_plugin_send (void *cls,
         }
       sa = GNUNET_CONNECTION_create_from_sockaddr (plugin->env->sched,
                                                    af, sb, sbs,
-                                                   GNUNET_SERVER_MAX_MESSAGE_SIZE);
+                                                   GNUNET_SERVER_MAX_MESSAGE_SIZE - 1);
       if (sa == NULL)
         {
 #if DEBUG_TCP
@@ -1991,7 +1991,7 @@ tcp_plugin_server_read (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc
    *  that wants to connect to us! Send a message to establish a connection.
    */
   sock = GNUNET_CONNECTION_create_from_sockaddr (plugin->env->sched, AF_INET, (struct sockaddr *)&in_addr,
-                                                 sizeof(in_addr), GNUNET_SERVER_MAX_MESSAGE_SIZE);
+                                                 sizeof(in_addr), GNUNET_SERVER_MAX_MESSAGE_SIZE - 1);
   if (sock == NULL)
     {
       plugin->server_read_task =
diff --git a/src/transport/test_plugin_transport_http.c b/src/transport/test_plugin_transport_http.c
index 75df9c90a..9c98d8c06 100644
--- a/src/transport/test_plugin_transport_http.c
+++ b/src/transport/test_plugin_transport_http.c
@@ -1036,15 +1036,6 @@ static void run_connection_tests( )
   api->send(api->cls, &my_identity, tmp, 425, 0, TIMEOUT, NULL,addr_head->addr, addr_head->addrlen, GNUNET_YES, &task_send_cont, NULL);*/
 
 
-  /* send a message with size GNUNET_SERVER_MAX_MESSAGE_SIZE )*/
-  /*
-  GNUNET_free(tmp);
-  tmp = GNUNET_malloc(GNUNET_SERVER_MAX_MESSAGE_SIZE);
-  uint16_t t2 = (uint16_t)GNUNET_SERVER_MAX_MESSAGE_SIZE;
-  msg.size = htons(t2);
-  memcpy(tmp,&msg,sizeof(struct GNUNET_MessageHeader));
-  api->send(api->cls, &my_identity, tmp, GNUNET_SERVER_MAX_MESSAGE_SIZE, 0, TIMEOUT, NULL,addr_head->addr, addr_head->addrlen, GNUNET_YES, &task_send_cont, &fail_msg_transmited_bigger_max_size);
-*/
   /* send a message with size GNUNET_SERVER_MAX_MESSAGE_SIZE-1  */
   GNUNET_free(tmp);
   tmp = GNUNET_malloc(GNUNET_SERVER_MAX_MESSAGE_SIZE-1);
diff --git a/src/transport/test_transport_api_reliability.c b/src/transport/test_transport_api_reliability.c
index 755d5a576..4f00fa0d9 100644
--- a/src/transport/test_transport_api_reliability.c
+++ b/src/transport/test_transport_api_reliability.c
@@ -46,7 +46,7 @@
  * 'MAX_PENDING' in 'gnunet-service-transport.c', otherwise
  * messages may be dropped even for a reliable transport.
  */
-#define TOTAL_MSGS (60000 * 2)
+#define TOTAL_MSGS (60000 * 20)
 
 /**
  * How long until we give up on transmitting the message?
@@ -152,6 +152,7 @@ static unsigned int
 get_size (unsigned int iter)
 {
   unsigned int ret;
+
   if (iter < 60000)
     return iter + sizeof (struct TestMessage);
   ret = (iter * iter * iter);
@@ -168,6 +169,7 @@ notify_receive (void *cls,
 {
   static int n;
   unsigned int s;
+  char cbuf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
   const struct TestMessage *hdr;
 
   hdr = (const struct TestMessage*) message;
@@ -196,6 +198,18 @@ notify_receive (void *cls,
       die_task = GNUNET_SCHEDULER_add_now (sched, &end_badly, NULL);
       return;
     }
+  memset (cbuf, n, s - sizeof (struct TestMessage));
+  if (0 != memcmp (cbuf,
+                   &hdr[1],
+                   s - sizeof (struct TestMessage)))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  "Expected message %u with bits %u, but body did not match\n",
+                  n, (unsigned char) n);
+      GNUNET_SCHEDULER_cancel (sched, die_task);
+      die_task = GNUNET_SCHEDULER_add_now (sched, &end_badly, NULL);
+      return;
+    }
 #if VERBOSE
   if (ntohl(hdr->num) % 5000 == 0)
     {
diff --git a/src/transport/transport_api.c b/src/transport/transport_api.c
index 2cd563178..d76ff6e5d 100644
--- a/src/transport/transport_api.c
+++ b/src/transport/transport_api.c
@@ -598,6 +598,7 @@ transport_notify_ready (void *cls, size_t size, void *buf)
 #endif
       if (mret != 0)    
         {
+          GNUNET_assert (mret + sizeof (struct OutboundMessage) < GNUNET_SERVER_MAX_MESSAGE_SIZE);
           obm.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
           obm.header.size = htons (mret + sizeof (struct OutboundMessage));
           obm.priority = htonl (th->priority);
@@ -1699,7 +1700,7 @@ GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
 #if DEBUG_TRANSPORT
       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                   "Message size is %d, max allowed is %d.\n",
-                  size + sizeof (struct OutboundMessage), GNUNET_SERVER_MAX_MESSAGE_SIZE);
+                  size + sizeof (struct OutboundMessage), GNUNET_SERVER_MAX_MESSAGE_SIZE - 1);
 #endif
       GNUNET_break (0);
       return NULL;
diff --git a/src/util/client.c b/src/util/client.c
index c7853d146..4ec40d032 100644
--- a/src/util/client.c
+++ b/src/util/client.c
@@ -291,7 +291,7 @@ do_connect (struct GNUNET_SCHEDULER_Handle *sched,
           sock = GNUNET_CONNECTION_create_from_connect_to_unixpath (sched,
                                                                     cfg,
                                                                     unixpath,
-                                                                    GNUNET_SERVER_MAX_MESSAGE_SIZE);
+                                                                    GNUNET_SERVER_MAX_MESSAGE_SIZE - 1);
           GNUNET_free (unixpath);
           if (sock != NULL)
             return sock;
@@ -328,7 +328,7 @@ do_connect (struct GNUNET_SCHEDULER_Handle *sched,
                                                 cfg,
                                                 hostname,
                                                 port,
-                                                GNUNET_SERVER_MAX_MESSAGE_SIZE);
+                                                GNUNET_SERVER_MAX_MESSAGE_SIZE - 1);
   GNUNET_free (hostname);
   return sock;
 }
@@ -579,7 +579,7 @@ GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *sock,
       GNUNET_assert (sock->in_receive == GNUNET_NO);
       sock->in_receive = GNUNET_YES;
       GNUNET_CONNECTION_receive (sock->sock,
-                                 GNUNET_SERVER_MAX_MESSAGE_SIZE,
+                                 GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                                  timeout, &receive_helper, sock);
     }
 }
diff --git a/src/util/connection.c b/src/util/connection.c
index 1631718e7..6c53bdef7 100644
--- a/src/util/connection.c
+++ b/src/util/connection.c
@@ -37,6 +37,7 @@
 #include "gnunet_container_lib.h"
 #include "gnunet_resolver_service.h"
 #include "gnunet_scheduler_lib.h"
+#include "gnunet_server_lib.h"
 
 #define DEBUG_CONNECTION GNUNET_NO
 
@@ -326,6 +327,7 @@ GNUNET_CONNECTION_create_from_existing (struct GNUNET_SCHEDULER_Handle
   struct GNUNET_CONNECTION_Handle *ret;
   ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle) + maxbuf);
   ret->write_buffer = (char *) &ret[1];
+  GNUNET_assert (maxbuf < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   ret->write_buffer_size = maxbuf;
   ret->sock = osSocket;
   ret->sched = sched;
@@ -416,6 +418,7 @@ GNUNET_CONNECTION_create_from_accept (struct GNUNET_SCHEDULER_Handle
     }
   ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle) + maxbuf);
   ret->write_buffer = (char *) &ret[1];
+  GNUNET_assert (maxbuf < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   ret->write_buffer_size = maxbuf;
   ret->addr = uaddr;
   ret->addrlen = addrlen;
@@ -873,6 +876,7 @@ GNUNET_CONNECTION_create_from_connect (struct GNUNET_SCHEDULER_Handle *sched,
   ret->cfg = cfg;
   ret->sched = sched;
   ret->write_buffer = (char *) &ret[1];
+  GNUNET_assert (maxbuf < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   ret->write_buffer_size = maxbuf;
   ret->port = port;
   ret->hostname = GNUNET_strdup (hostname);
@@ -929,6 +933,7 @@ GNUNET_CONNECTION_create_from_connect_to_unixpath (struct GNUNET_SCHEDULER_Handl
   ret->cfg = cfg;
   ret->sched = sched;
   ret->write_buffer = (char *) &ret[1];
+  GNUNET_assert (maxbuf < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   ret->write_buffer_size = maxbuf;
   ret->port = 0;
   ret->hostname = NULL;
diff --git a/src/util/resolver_api.c b/src/util/resolver_api.c
index 8905810d4..f4832ed9c 100644
--- a/src/util/resolver_api.c
+++ b/src/util/resolver_api.c
@@ -426,12 +426,11 @@ GNUNET_RESOLVER_ip_get (struct GNUNET_SCHEDULER_Handle *sched,
   unsigned int i;
   struct in_addr v4;
   struct in6_addr v6;
-  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
 
   check_config (cfg);
   slen = strlen (hostname) + 1;
-  if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >
-      GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
     {
       GNUNET_break (0);
       return NULL;
@@ -619,7 +618,7 @@ GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched,
   struct GNUNET_CLIENT_Connection *client;
   struct GNUNET_RESOLVER_GetMessage *msg;
   struct GNUNET_RESOLVER_RequestHandle *rh;
-  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
 
   check_config (cfg);
   rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen);
@@ -636,8 +635,7 @@ GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched,
                                            &numeric_reverse, rh);
       return rh;
     }
-  if (salen + sizeof (struct GNUNET_RESOLVER_GetMessage) >
-      GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (salen + sizeof (struct GNUNET_RESOLVER_GetMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
     {
       GNUNET_break (0);
       GNUNET_free (rh);
diff --git a/src/util/server.c b/src/util/server.c
index c31168e8c..606d44369 100644
--- a/src/util/server.c
+++ b/src/util/server.c
@@ -701,7 +701,7 @@ process_mst (struct GNUNET_SERVER_Client *client,
                       "Server re-enters receive loop.\n");
 #endif
           GNUNET_CONNECTION_receive (client->connection,
-                                     GNUNET_SERVER_MAX_MESSAGE_SIZE,
+                                     GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                                      client->server->idle_timeout, 
                                      &process_incoming, client);
           break;
@@ -811,7 +811,7 @@ restart_processing (void *cls,
 #endif
       client->receive_pending = GNUNET_YES;
       GNUNET_CONNECTION_receive (client->connection,
-                                 GNUNET_SERVER_MAX_MESSAGE_SIZE,
+                                 GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                                  client->server->idle_timeout, &process_incoming, client);
       return;
     }
@@ -877,7 +877,7 @@ GNUNET_SERVER_connect_socket (struct
 
   client = GNUNET_malloc (sizeof (struct GNUNET_SERVER_Client));
   client->connection = connection;
-  client->mst = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE,
+  client->mst = GNUNET_SERVER_mst_create (GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                                           &client_message_tokenizer_callback,
                                           server);
   client->reference_count = 1;
@@ -887,7 +887,7 @@ GNUNET_SERVER_connect_socket (struct
   server->clients = client;
   client->receive_pending = GNUNET_YES;
   GNUNET_CONNECTION_receive (client->connection,
-                             GNUNET_SERVER_MAX_MESSAGE_SIZE,
+                             GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
                              server->idle_timeout, &process_incoming, client);
   return client;
 }
diff --git a/src/util/server_mst.c b/src/util/server_mst.c
index 29c04e96c..9dc47e94b 100644
--- a/src/util/server_mst.c
+++ b/src/util/server_mst.c
@@ -84,7 +84,7 @@ struct GNUNET_SERVER_MessageStreamTokenizer
  * Create a message stream tokenizer.
  *
  * @param maxbuf maximum message size to support (typically
- *    GNUNET_SERVER_MAX_MESSAGE_SIZE)
+ *    GNUNET_SERVER_MAX_MESSAGE_SIZE - 1)
  * @param cb function to call on completed messages
  * @param cb_cls closure for cb
  * @return handle to tokenizer
diff --git a/src/util/service.c b/src/util/service.c
index cff701a3c..46a01a098 100644
--- a/src/util/service.c
+++ b/src/util/service.c
@@ -1140,7 +1140,7 @@ setup_service (struct GNUNET_SERVICE_Context *sctx)
         }
     }
   else
-    maxbuf = GNUNET_SERVER_MAX_MESSAGE_SIZE;
+    maxbuf = GNUNET_SERVER_MAX_MESSAGE_SIZE - 1;
 
   if (GNUNET_CONFIGURATION_have_value (sctx->cfg,
                                        sctx->serviceName, "TOLERANT"))
@@ -1577,7 +1577,7 @@ GNUNET_SERVICE_run (int argc,
   sctx.ready_confirm_fd = -1;
   sctx.ret = GNUNET_OK;
   sctx.timeout = GNUNET_TIME_UNIT_FOREVER_REL;
-  sctx.maxbuf = GNUNET_SERVER_MAX_MESSAGE_SIZE;
+  sctx.maxbuf = GNUNET_SERVER_MAX_MESSAGE_SIZE - 1;
   sctx.task = task;
   sctx.serviceName = serviceName;
   sctx.cfg = cfg = GNUNET_CONFIGURATION_create ();
@@ -1656,7 +1656,7 @@ GNUNET_SERVICE_start (const char *serviceName,
   sctx->ready_confirm_fd = -1;  /* no daemonizing */
   sctx->ret = GNUNET_OK;
   sctx->timeout = GNUNET_TIME_UNIT_FOREVER_REL;
-  sctx->maxbuf = GNUNET_SERVER_MAX_MESSAGE_SIZE;
+  sctx->maxbuf = GNUNET_SERVER_MAX_MESSAGE_SIZE - 1;
   sctx->serviceName = serviceName;
   sctx->cfg = cfg;
   sctx->sched = sched;