[syslinux] Added DHCPINFO Tables to the lua.c32 Implementation - syslinux-4.04
Timm Gleason
timmgleason at gmail.com
Tue Oct 4 08:06:13 PDT 2011
Greetings All.
We wanted to be able to parse the DHCP values and options and write a lua
script based on the information found. We are also using the CPU flags, but
thankfully in at least version 4.04 there is already some CPU value parsing
even if it isn't documented. Using the information from the CPU table we
wanted to be able to choose the kernel to boot. Using the DHCP table
information, we wanted to pass the DHCP values of our choosing to the
kernel.
This patch will provide access to two tables within a lua script when using
the lua.c32 binary to do pxelinux booting. It basically adds another module
such as dmi, pci, or vesa to the lua implementation.
gettable() returns a table of the BOOTP message fields returned by the DHCP
server for use in a Lua pxeboot script
See http://tools.ietf.org/html/rfc1542
lua key value RFC key
-----------------------------------------------------------------------
opcode op message opcode
hardware.type htype Hardware address type
hardware.length hlen Hardware address length
hops hops Used by relay agents
transaction.id xid transaction id
elapsed.seconds secs Secs elapsed since client boot
flags flags DHCP Flags field
client.ip.addr ciaddr client IP addr
your.ip.addr yiaddr 'Your' IP addr. (from server)
server.ip.addr siaddr Boot server IP addr
gateway.ip.addr giaddr Relay agent IP addr
client.mac chaddr Client hardware addr
server.hostname sname Optl. boot server hostname
boot.file file boot file name (ascii path)
magic.cookie cookie Magic cookie
getoptions() returns a table of the DHCP Options field of the BOOTP
message returned by the DHCP server for use in a Lua pxeboot script.
Many of the options are reurned formatted in as strings in a standard,
1, 2, and 4 byte numerical options are returned as integers.
Other Options with non-standard formats are returned as strings of the
raw binary number that was returned by the DHCP server and must be decoded
in a Lua script
The Options table returns the Option code as the key except where there
are multiple values returned. In those cases, an extra key increment number
is added to allow individual access to each Option value.
lua key value value Name
-----------------------------------------------------------------------
1 Subnet Mask
6.1 DNS Server [element 1]
6.2 DNS Server [element 2]
6.3 DNS Server [element 3]
209 PXE Configuration File
21.1 Policy Filter [element 1]
21.2 Policy Filter [element 2]
Options that can have a list of values, but contain only one (like Option 6)
will not return with .sub key values.
Usage:
t = dhcp.gettable()
for k,v in pairs(t) do
print(k.." : "..v)
end
Hope someone else finds it useful!
Regards,
Timm Gleason
--
"Be Impeccable with your Word - Don't Take Anything Personally - Don't Make
Assumptions - Always Do Your Best"
<http://gleason.to/leech/OLYMPICS_thumb.jpg>diff -up
syslinux-4.04/com32/lua/src/dhcp.c.orig syslinux-4.04/com32/lua/src/dhcp.c
--- syslinux-4.04/com32/lua/src/dhcp.c.orig 2011-09-28 13:09:33.000000000
-0700
+++ syslinux-4.04/com32/lua/src/dhcp.c 2011-09-28 13:10:26.000000000
-0700
@@ -0,0 +1,358 @@
+/* -----------------------------------------------------------------------
*
+ *
+ * Copyright 2007 H. Peter Anvin - All Rights Reserved
+ * Copyright 2011 Timothy J Gleason <timmgleason_at_gmail.com> - All
Rights Reserved
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall
+ * be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * -----------------------------------------------------------------------
*/
+
+/*
+ * dhcp.c
+ *
+ * Adds DHCPINFO functionality to the lua.c32 binary
+ *
+ * gettable() returns a table of the BOOTP message fields returned by
+ * the DHCP server for use in a Lua pxeboot script
+ * See http://tools.ietf.org/html/rfc1542
+ *
+ * lua key value RFC key
+ * -----------------------------------------------------------------------
+ * opcode op message opcode
+ * hardware.type htype Hardware address type
+ * hardware.length hlen Hardware address length
+ * hops hops Used by relay agents
+ * transaction.id xid transaction id
+ * elapsed.seconds secs Secs elapsed since client boot
+ * flags flags DHCP Flags field
+ * client.ip.addr ciaddr client IP addr
+ * your.ip.addr yiaddr 'Your' IP addr. (from server)
+ * server.ip.addr siaddr Boot server IP addr
+ * gateway.ip.addr giaddr Relay agent IP addr
+ * client.mac chaddr Client hardware addr
+ * server.hostname sname Optl. boot server hostname
+ * boot.file file boot file name (ascii path)
+ * magic.cookie cookie Magic cookie
+ *
+ * getoptions() returns a table of the DHCP Options field of the BOOTP
+ * message returned by the DHCP server for use in a Lua pxeboot script.
+ * Many of the options are reurned formatted in as strings in a standard,
+ * recognizable format, such as IP addresses.
+ *
+ * 1, 2, and 4 byte numerical options are returned as integers.
+ *
+ * Other Options with non-standard formats are returned as strings of the
+ * raw binary number that was returned by the DHCP server and must be
decoded
+ * in a Lua script
+ *
+ * The Options table returns the Option code as the key except where there
+ * are multiple values returned. In those cases, an extra key increment
number
+ * is added to allow individual access to each Option value.
+ *
+ * lua key value value Name
+ * -----------------------------------------------------------------------
+ * 1 Subnet Mask
+ * 6.1 DNS Server [element 1]
+ * 6.2 DNS Server [element 2]
+ * 6.3 DNS Server [element 3]
+ * 209 PXE Configuration File
+ * 21.1 Policy Filter [element 1]
+ * 21.2 Policy Filter [element 2]
+ *
+ * Options that can have a list of values, but contain only one (like
Option 6)
+ * will not return with .sub key values.
+ *
+ * Usage:
+ t = dhcp.gettable()
+
+ for k,v in pairs(t) do
+ print(k.." : "..v)
+ end
+ */
+
+#include <stdio.h>
+#include "dhcp.h"
+#include "lua.h"
+#include "lauxlib.h"
+#include "lualib.h"
+#include <syslinux/pxe.h>
+
+#define STR_BUF_SIZE 129 /* Sized to accomdate File field in BOOTP
message */
+
+void
+ip_address_list(lua_State *L, uint8_t* value, uint8_t len, uint8_t option )
+{
+ static char op_name[64];
+ static char op_value[255];
+ int loop;
+
+ loop = len/4;
+
+ if ( loop == 1) {
+ sprintf(op_name, "%u", option);
+ lua_pushstring(L, op_name);
+ sprintf(op_value, "%u.%u.%u.%u", value[0], value[1], value[2],
value[3]);
+ lua_pushstring(L, op_value);
+ lua_settable(L,-3);
+ } else {
+ for (int done = 0; done < loop; done++){
+ sprintf(op_name, "%u.%d", option, done+1);
+ lua_pushstring(L, op_name);
+ sprintf(op_value, "%u.%u.%u.%u", value[0+(done*4)], value[1+(done*4)],
value[2+(done*4)], value[3+(done*4)]);
+ lua_pushstring(L, op_value);
+ lua_settable(L,-3);
+ }
+ }
+
+}
+
+static int dhcp_getoptions(lua_State *L)
+{
+ void* dhcpdata = 0;
+ dhcp_t* dhcp = 0;
+ size_t dhcplen = 0;
+
+ /* Append the DHCP info */
+ if (pxe_get_cached_info(PXENV_PACKET_TYPE_DHCP_ACK,
+ &dhcpdata, &dhcplen))
+ {
+ return 0;
+ }
+
+ dhcp = (dhcp_t*)dhcpdata;
+
+ lua_newtable(L);
+
+ int done = 0;
+ uint8_t* ptr = (uint8_t*)&dhcp->options;
+ uint8_t len;
+ uint8_t option;
+ uint8_t* value;
+ static char op_name[64];
+
+ do {
+ option = *ptr++;
+ len = *ptr++;
+ value = ptr;
+ ptr += len;
+ switch (option) {
+// IP Address formatted lists, including singles
+ case 1:
+ case 3:
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ case 8:
+ case 9:
+ case 10:
+ case 11:
+ case 16:
+ case 21: /* Policy Filters - address/mask */
+ case 28:
+ case 32:
+ case 33: /* Static routes - destination/router */
+ case 41:
+ case 42:
+ case 44:
+ case 45:
+ case 47:
+ case 48:
+ case 49:
+ case 50:
+ case 51:
+ case 54:
+ case 65:
+ case 68:
+ case 69:
+ case 70:
+ case 71:
+ case 72:
+ case 73:
+ case 74:
+ case 75:
+ case 76:
+ ip_address_list(L, value, len, option);
+ break;
+// 4byte options - numerical
+ case 2:
+ case 24:
+ case 35:
+ case 38:
+ case 58:
+ case 59:
+ case 211:
+ sprintf(op_name, "%u", option);
+ lua_pushstring(L, op_name);
+ lua_pushinteger(L, ntohl(*(long*)value));
+ lua_settable(L,-3);
+ break;
+// 2byte options -numerical
+ case 13:
+ case 22:
+ case 26:
+ case 57:
+ sprintf(op_name, "%u", option);
+ lua_pushstring(L, op_name);
+ lua_pushinteger(L, ntohs(*(short*)value));
+ lua_settable(L,-3);
+ break;
+// 1byte options - numerical
+ case 19:
+ case 20:
+ case 23:
+ case 27:
+ case 29:
+ case 30:
+ case 31:
+ case 34:
+ case 36:
+ case 37:
+ case 39:
+ case 46:
+ case 52:
+ case 53:
+ sprintf(op_name, "%u", option);
+ lua_pushstring(L, op_name);
+ lua_pushinteger(L, *value);
+ lua_settable(L,-3);
+ break;
+ case 255:
+ done = 1;
+ break;
+ default:
+ sprintf(op_name, "%u", option);
+ lua_pushstring(L, op_name);
+ lua_pushlstring(L, (const char*)value, len);
+ lua_settable(L,-3);
+ break;
+ }
+
+ } while (!done);
+
+ return 1;
+}
+
+static int dhcp_gettable(lua_State *L)
+{
+ void* dhcpdata = 0;
+ dhcp_t* dhcp = 0;
+ size_t dhcplen = 0;
+ static char dhcp_arg[STR_BUF_SIZE];
+
+ /* Append the DHCP info */
+ if (pxe_get_cached_info(PXENV_PACKET_TYPE_DHCP_ACK,
+ &dhcpdata, &dhcplen))
+ {
+ return 0;
+ }
+
+ dhcp = (dhcp_t*)dhcpdata;
+
+
+ lua_newtable(L);
+
+ lua_pushstring(L, "opcode");
+ lua_pushinteger(L, dhcp->op);
+ lua_settable(L,-3);
+
+ lua_pushstring(L, "hardware.type");
+ lua_pushinteger(L, dhcp->htype);
+ lua_settable(L,-3);
+
+ lua_pushstring(L, "hardware.length");
+ lua_pushinteger(L, dhcp->hlen);
+ lua_settable(L,-3);
+
+ lua_pushstring(L, "hops");
+ lua_pushinteger(L, dhcp->hops);
+ lua_settable(L,-3);
+
+ lua_pushstring(L, "transaction.id");
+ lua_pushinteger(L, ntohl(dhcp->xid));
+ lua_settable(L,-3);
+
+ lua_pushstring(L, "elapsed.seconds");
+ lua_pushinteger(L, ntohs(dhcp->secs));
+ lua_settable(L,-3);
+
+ lua_pushstring(L, "flags");
+ lua_pushinteger(L, ntohs(dhcp->flags));
+ lua_settable(L,-3);
+
+ sprintf(dhcp_arg, "%u.%u.%u.%u", dhcp->ciaddr[0], dhcp->ciaddr[1],
dhcp->ciaddr[2], dhcp->ciaddr[3]);
+ lua_pushstring(L, "client.ip.addr");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ sprintf(dhcp_arg, "%u.%u.%u.%u", dhcp->yiaddr[0], dhcp->yiaddr[1],
dhcp->yiaddr[2], dhcp->yiaddr[3]);
+ lua_pushstring(L, "your.ip.addr");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ sprintf(dhcp_arg, "%u.%u.%u.%u", dhcp->siaddr[0], dhcp->siaddr[1],
dhcp->siaddr[2], dhcp->siaddr[3]);
+ lua_pushstring(L, "server.ip.addr");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ sprintf(dhcp_arg, "%u.%u.%u.%u", dhcp->giaddr[0], dhcp->giaddr[1],
dhcp->giaddr[2], dhcp->giaddr[3]);
+ lua_pushstring(L, "gateway.ip.addr");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ sprintf(dhcp_arg, "%02X:%02X:%02X:%02X:%02X:%02X",
+ dhcp->chaddr[0], dhcp->chaddr[1], dhcp->chaddr[2],
+ dhcp->chaddr[3], dhcp->chaddr[4], dhcp->chaddr[5]);
+ lua_pushstring(L, "client.mac");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ snprintf(dhcp_arg, STR_BUF_SIZE, "%s", dhcp->sname);
+ dhcp_arg[STR_BUF_SIZE-1] = 0; /* Guarantee for lua_pushstring that
dhcp_arg is 0 terminated /*/
+ lua_pushstring(L, "server.hostname");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ snprintf(dhcp_arg, STR_BUF_SIZE, "%s", dhcp->file);
+ dhcp_arg[STR_BUF_SIZE-1] = 0; /* Guarantee for lua_pushstring that
dhcp_arg is 0 terminated /*/
+ lua_pushstring(L, "boot.file");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ sprintf(dhcp_arg, "%u.%u.%u.%u", dhcp->cookie[0], dhcp->cookie[1],
dhcp->cookie[2], dhcp->cookie[3]);
+ lua_pushstring(L, "magic.cookie");
+ lua_pushstring(L, dhcp_arg);
+ lua_settable(L,-3);
+
+ return 1;
+}
+
+static const luaL_reg dhcplib[] = {
+ {"gettable", dhcp_gettable},
+ {"getoptions", dhcp_getoptions},
+ {NULL, NULL}
+};
+
+LUALIB_API int luaopen_dhcp (lua_State *L) {
+ luaL_openlib(L, LUA_DHCPLIBNAME, dhcplib, 0);
+ return 1;
+}
diff -up syslinux-4.04/com32/lua/src/dhcp.h.orig
syslinux-4.04/com32/lua/src/dhcp.h
--- syslinux-4.04/com32/lua/src/dhcp.h.orig 2011-09-28 13:09:36.000000000
-0700
+++ syslinux-4.04/com32/lua/src/dhcp.h 2011-09-28 13:10:26.000000000
-0700
@@ -0,0 +1,49 @@
+/* -----------------------------------------------------------------------
*
+ *
+ * Copyright 2007 H. Peter Anvin - All Rights Reserved
+ * Copyright 2011 Timothy J Gleason <timmgleason_at_gmail.com> - All
Rights Reserved
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall
+ * be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * -----------------------------------------------------------------------
*/
+
+#include <stdint.h>
+
+typedef struct dhcp {
+ uint8_t op; /* message opcode */
+ uint8_t htype; /* Hardware address type */
+ uint8_t hlen; /* Hardware address length */
+ uint8_t hops; /* Used by relay agents */
+ uint32_t xid; /* transaction id */
+ uint16_t secs; /* Secs elapsed since client boot */
+ uint16_t flags; /* DHCP Flags field */
+ uint8_t ciaddr[4]; /* client IP addr */
+ uint8_t yiaddr[4]; /* 'Your' IP addr. (from server) */
+ uint8_t siaddr[4]; /* Boot server IP addr */
+ uint8_t giaddr[4]; /* Relay agent IP addr */
+ uint8_t chaddr[16]; /* Client hardware addr */
+ uint8_t sname[64]; /* Optl. boot server hostname */
+ uint8_t file[128]; /* boot file name (ascii path) */
+ uint8_t cookie[4]; /* Magic cookie */
+ uint8_t options[1020]; /* Options */
+} dhcp_t;
+
diff -up syslinux-4.04/com32/lua/src/linit.c.orig
syslinux-4.04/com32/lua/src/linit.c
--- syslinux-4.04/com32/lua/src/linit.c.orig 2011-04-18
14:24:17.000000000 -0700
+++ syslinux-4.04/com32/lua/src/linit.c 2011-09-28 13:10:14.000000000
-0700
@@ -33,6 +33,7 @@ static const luaL_Reg lualibs[] = {
{LUA_PCILIBNAME, luaopen_pci},
{LUA_SYSLINUXLIBNAME, luaopen_syslinux},
{LUA_VESALIBNAME, luaopen_vesa},
+ {LUA_DHCPLIBNAME, luaopen_dhcp},
#endif
{NULL, NULL}
};
diff -up syslinux-4.04/com32/lua/src/lualib.h.orig
syslinux-4.04/com32/lua/src/lualib.h
--- syslinux-4.04/com32/lua/src/lualib.h.orig 2011-04-18
14:24:17.000000000 -0700
+++ syslinux-4.04/com32/lua/src/lualib.h 2011-09-28 13:10:18.000000000
-0700
@@ -54,6 +54,9 @@ LUALIB_API int (luaopen_vesa) (lua_State
#define LUA_CPULIBNAME "cpu"
LUALIB_API int (luaopen_cpu) (lua_State *L);
+
+#define LUA_DHCPLIBNAME "dhcp"
+LUALIB_API int (luaopen_dhcp) (lua_State *L);
#endif
/* open all previous libraries */
diff -up syslinux-4.04/com32/lua/src/Makefile.orig
syslinux-4.04/com32/lua/src/Makefile
--- syslinux-4.04/com32/lua/src/Makefile.orig 2011-04-18
14:24:17.000000000 -0700
+++ syslinux-4.04/com32/lua/src/Makefile 2011-09-28 13:10:32.000000000
-0700
@@ -44,6 +44,7 @@ LIBLUA_OBJS += dmi.o
LIBLUA_OBJS += cpu.o
LIBLUA_OBJS += pci.o
LIBLUA_OBJS += vesa.o
+LIBLUA_OBJS += dhcp.o
CFLAGS += -DLUA_ANSI
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