*/
+/* Protocol documentation:
+ * 8 bytes: "UDPGate0" (55 44 50 47 61 74 65 30) = Packet identifier
+ * Follows arbitrary number of elements in no particular order.
+ * Structure of each such element:
+ * 4 bytes: element identifier; network byte order
+ * bit 31 (0x80000000) means mandatory element:
+ * If the element is not recognized the packet must be dropped.
+ * bits 0..30 (0x7FFFFFFF) specify element id.
+ * 4 bytes: element data length; network byte order
+ * X bytes: element data; minimal data alignment is 1 byte (=no alignment)
+ * Known elements; see: http://cvs.jankratochvil.net/viewcvs/udpgate/src/packet.h?rev=HEAD
+ * PROGRAM_VERSION: data=string (no zero terminator); currently "1.0"
+ * This element is currently ignored.
+ * CLIENT_INADDR: Client IPv4 address; network byte order; length=4B
+ * CLIENT_PORT: Client IPv4 port; network byte order; length=2B
+ * DATA_GUINT32: Session unique number; network byte order; length=4B
+ * Reply packet will copy this element intact.
+ * Step 1:
+ * Client sends from port A (35545 here) to port 8201 (probe port) packet:
+ * PROGRAM_VERSION (of the client udpgate)
+ * CLIENT_PORT (chosen port; default is 9201)
+ * DATA_GUINT32 (chosen random number)
+ * Example:
+ * 09:07:01.966123 127.0.0.1.35545 > 127.0.0.1.8201: udp 44 (DF)
+ * 16=$0010: <UDP packet headers................> 55 44 50 47 | UDPG
+ * 32=$0020: 61 74 65 30 80 00 00 01 00 00 00 06 31 2E 30 63 | ate0........1.0c
+ * 48=$0030: 76 73 80 00 00 03 00 00 00 02 1A 0A 80 00 00 04 | vs..............
+ * 64=$0040: 00 00 00 04 99 E1 4B 04 | ......K.
+ * Step 2:
+ * Probe server replies from port B (currently always 8201) to the packet
+ * originating address CLIENT_INADDR and the received CLIENT_PORT:
+ * PROGRAM_VERSION (of the probe server)
+ * CLIENT_INADDR (detected from the originating packet address)
+ * DATA_GUINT32 (copied from the request packet)
+ * Example:
+ * 09:07:01.970252 127.0.0.1.8201 > 127.0.0.1.6666: udp 46 (DF)
+ * 16=$0010: <UDP packet headers................> 55 44 50 47 | UDPG
+ * 32=$0020: 61 74 65 30 80 00 00 01 00 00 00 06 31 2E 30 63 | ate0........1.0c
+ * 48=$0030: 76 73 80 00 00 02 00 00 00 04 7F 00 00 01 80 00 | vs..............
+ * 64=$0040: 00 04 00 00 00 04 99 E1 4B 04 | ........K.
+ * Step 3:
+ * Client must ignore probe replies with nonmatching DATA_GUINT32.
+ * Client will stop if no probe reply is received in PROBE_TIMEOUT_SEC.
+ * Client displays the received CLIENT_INADDR to the user.
+ */
+
+
#include "config.h"
#include <glib/gmessages.h>
#include <glib/gslist.h>
#include "packet.h"
+#include "main.h" /* for optarg_verbose */
+
+
+#define PACKET_VERSION_STRING (VERSION "-gnome")
+
static void packet_assembly_guint32(GString *gstring,guint32 value_guint32)
{
static void packet_assembly_data_guint32(GString *gstring,guint32 value_guint32)
{
-guint32 value_guint32_htonl=htonl(value_guint32);
-
g_return_if_fail(gstring!=NULL);
- g_assert(4==sizeof(value_guint32_htonl));
- packet_assembly_guint32(gstring,sizeof(value_guint32_htonl));
- packet_assembly_guint32(gstring,value_guint32_htonl);
+ g_assert(4==sizeof(value_guint32));
+ packet_assembly_guint32(gstring,sizeof(value_guint32));
+ packet_assembly_guint32(gstring,value_guint32);
}
static void packet_assembly_data_guint16(GString *gstring,guint16 value_guint16)
{
-guint16 value_guint16_htonl=htons(value_guint16);
-
g_return_if_fail(gstring!=NULL);
- g_assert(2==sizeof(value_guint16_htonl));
- packet_assembly_guint32(gstring,sizeof(value_guint16_htonl));
- packet_assembly_guint16(gstring,value_guint16_htonl);
+ g_assert(2==sizeof(value_guint16));
+ packet_assembly_guint32(gstring,sizeof(value_guint16));
+ packet_assembly_guint16(gstring,value_guint16);
}
static void packet_assembly_data_string(GString *gstring,const gchar *string)
switch (elem_type_uint32) {
case PACKET_ELEM_TYPE_PROGRAM_VERSION:
packet_assembly_data_string(gstring,value);
+ if (optarg_verbose)
+ g_message(_("Assembled PROGRAM_VERSION: %s"),(const char *)value);
break;
case PACKET_ELEM_TYPE_CLIENT_INADDR:
+ packet_assembly_data_guint32(gstring,GPOINTER_TO_UINT(value));
+ if (optarg_verbose)
+ g_message(_("Assembled CLIENT_INADDR: %s"),HOSTIP_GUINT32_TO_STRING(GPOINTER_TO_UINT(value)));
+ break;
case PACKET_ELEM_TYPE_DATA_GUINT32:
packet_assembly_data_guint32(gstring,GPOINTER_TO_UINT(value));
+ if (optarg_verbose)
+ g_message(_("Assembled DATA_GUINT32: 0x%08X"),(unsigned)GPOINTER_TO_UINT(value));
break;
case PACKET_ELEM_TYPE_CLIENT_PORT:
packet_assembly_data_guint16(gstring,GPOINTER_TO_UINT(value));
+ if (optarg_verbose)
+ g_message(_("Assembled CLIENT_PORT: %d"),(int)GPOINTER_TO_UINT(value));
break;
default:
g_assert_not_reached();
g_return_val_if_fail(packet_length_pointer!=NULL,NULL);
g_return_val_if_fail(values!=NULL,NULL);
+ if (optarg_verbose)
+ g_message(_("Assembling packet..."));
+
gstring=g_string_new(NULL);
g_string_append(gstring,PACKET_HEADER);
- packet_assembly_foreach(GINT_TO_POINTER(PACKET_ELEM_TYPE_PROGRAM_VERSION),VERSION,gstring);
+ packet_assembly_foreach(GINT_TO_POINTER(PACKET_ELEM_TYPE_PROGRAM_VERSION),PACKET_VERSION_STRING,gstring);
g_hash_table_foreach(
values, /* hash_table */
(GHFunc)packet_assembly_foreach, /* func */
gstring); /* user_data */
+ if (optarg_verbose)
+ g_message(_("Packet assembly done."));
+
*packet_length_pointer=gstring->len;
return g_string_free(gstring,
FALSE); /* free_segment */
return TRUE;
}
+gboolean packet_recognized(gconstpointer packet,size_t packet_length)
+{
+ if (strlen(PACKET_HEADER)>packet_length)
+ return FALSE;
+ if (memcmp(packet,PACKET_HEADER,strlen(PACKET_HEADER)))
+ return FALSE;
+ return TRUE;
+}
+
GHashTable *packet_disassembly(gconstpointer packet,size_t packet_length)
{
GHashTable *r;
g_return_val_if_fail(packet!=NULL,NULL);
+ if (optarg_verbose)
+ g_message(_("Decoding packet..."));
+
r=g_hash_table_new_full(
g_direct_hash, /* hash_func */
g_direct_equal, /* key_equal_func */
case PACKET_ELEM_TYPE_PROGRAM_VERSION:
if (!packet_disassembly_data_string(&value,elem_data,elem_data_length_guint32,&items))
goto err_packet_disassembly_destroy_value_destroy_func_items;
+ if (optarg_verbose)
+ g_message(_("Decoded PROGRAM_VERSION: %s"),(const char *)value);
break;
case PACKET_ELEM_TYPE_CLIENT_INADDR:
+ if (!packet_disassembly_data_guint32(&value,elem_data,elem_data_length_guint32,&items))
+ goto err_packet_disassembly_destroy_value_destroy_func_items;
+ if (optarg_verbose)
+ g_message(_("Decoded CLIENT_INADDR: %s"),HOSTIP_GUINT32_TO_STRING(GPOINTER_TO_UINT(value)));
+ break;
case PACKET_ELEM_TYPE_DATA_GUINT32:
if (!packet_disassembly_data_guint32(&value,elem_data,elem_data_length_guint32,&items))
goto err_packet_disassembly_destroy_value_destroy_func_items;
+ if (optarg_verbose)
+ g_message(_("Decoded DATA_GUINT32: 0x%08X"),(unsigned)GPOINTER_TO_UINT(value));
break;
case PACKET_ELEM_TYPE_CLIENT_PORT:
if (!packet_disassembly_data_guint16(&value,elem_data,elem_data_length_guint32,&items))
goto err_packet_disassembly_destroy_value_destroy_func_items;
+ if (optarg_verbose)
+ g_message(_("Decoded CLIENT_PORT: %d"),GPOINTER_TO_UINT(value));
break;
default:
- if (elem_type_guint32&PACKET_ELEM_ATTR_MANDATORY)
+ if (elem_type_guint32&PACKET_ELEM_ATTR_MANDATORY) {
+ if (optarg_verbose)
+ g_message(_("Decoding failed on ATTR_MANDATORY ELEM code 0x%08X"),(unsigned)elem_type_guint32);
goto err_packet_disassembly_destroy_value_destroy_func_items;
- else /* ignore the PACKET_ELEM_ATTR_OPTIONAL packet */;
+ }
+ else {
+ if (optarg_verbose)
+ g_message(_("Decoding ignores ATTR_OPTIONAL ELEM code 0x%08X"),(unsigned)elem_type_guint32);
+ }
continue;
}
g_hash_table_insert(r,GUINT_TO_POINTER(elem_type_guint32),value);
packet_disassembly_destroy_registry_init();
g_hash_table_insert(packet_disassembly_destroy_registry,r,items);
+ if (optarg_verbose)
+ g_message(_("Decoding done."));
+
return r;
}
git://git.jankratochvil.net / udpgate.git / blobdiff