pxe: Re-add support for embedded DHCP optionssyslinux-6.03-pre15

Fix the support for embedded DHCP options.  Although we were
diligently saving them away, we never actually parsed them.

This fixes embedded options for BIOS only -- for EFI we need to modify
the encoding scheme so that it can fit inside an EFI PECOFF image.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

4 files changed, 23 insertions, 3 deletions

diff --git a/core/fs/pxe/bios.c b/core/fs/pxe/bios.c
index 6d514df2..6eb37626 100644
--- a/core/fs/pxe/bios.c
+++ b/core/fs/pxe/bios.c
@@ -5,6 +5,7 @@
 #include <net.h>
 #include <minmax.h>
 #include <bios.h>
+#include <dprintf.h>
 
 static uint16_t real_base_mem;	   /* Amount of DOS memory after freeing */
 
@@ -385,6 +386,9 @@ cant_free:
     return;
 }
 
+extern const char bdhcp_data[], adhcp_data[];
+extern const uint32_t bdhcp_len, adhcp_len;
+
 void net_parse_dhcp(void)
 {
     int pkt_len;
@@ -400,11 +404,18 @@ void net_parse_dhcp(void)
     *LocalDomain = 0;   /* No LocalDomain received */
 
     /*
+     * Parse any "before" hardcoded options
+     */
+    dprintf("DHCP: bdhcp_len = %d\n", bdhcp_len);
+    parse_dhcp_options(bdhcp_data, bdhcp_len, 0);
+
+    /*
      * Get the DHCP client identifiers (query info 1)
      */
     ddprintf("Getting cached packet ");
     pkt_len = pxe_get_cached_info(1, bp, dhcp_max_packet);
     parse_dhcp(bp, pkt_len);
+
     /*
      * We don't use flags from the request packet, so
      * this is a good time to initialize DHCPMagic...
@@ -439,5 +450,11 @@ void net_parse_dhcp(void)
     parse_dhcp(bp, pkt_len);
     ddprintf("\n");
 
+    /*
+     * Parse any "after" hardcoded options
+     */
+    dprintf("DHCP: adhcp_len = %d\n", adhcp_len);
+    parse_dhcp_options(adhcp_data, adhcp_len, 0);
+
     lfree(bp);
 }
diff --git a/core/fs/pxe/dhcp_option.c b/core/fs/pxe/dhcp_option.c
index 3517161a..1fdcc705 100644
--- a/core/fs/pxe/dhcp_option.c
+++ b/core/fs/pxe/dhcp_option.c
@@ -3,6 +3,7 @@
 #include <core.h>
 #include <sys/cpu.h>
 #include <lwip/opt.h>		/* DNS_MAX_SERVERS */
+#include <dprintf.h>
 #include "pxe.h"
 
 char LocalDomain[256];
@@ -11,8 +12,6 @@ int over_load;
 uint8_t uuid_type;
 uint8_t uuid[16];
 
-static void parse_dhcp_options(const void *, int, uint8_t);
-
 static void subnet_mask(const void *data, int opt_len)
 {
     if (opt_len != 4)
@@ -164,7 +163,7 @@ static const struct dhcp_options dhcp_opts[] = {
  * filter  contains the minimum value for the option to recognize
  * -- this is used to restrict parsing to PXELINUX-specific options only.
  */
-static void parse_dhcp_options(const void *option, int size, uint8_t opt_filter)
+void parse_dhcp_options(const void *option, int size, uint8_t opt_filter)
 {
     int opt_num;
     int opt_len;
@@ -189,6 +188,8 @@ static void parse_dhcp_options(const void *option, int size, uint8_t opt_filter)
         if (size < 0)
             break;
 
+	dprintf("DHCP: option %d, len %d\n", opt_num, opt_len);
+
 	if (opt_num >= opt_filter) {
 	    opt = dhcp_opts;
 	    for (i = 0; i < opt_entries; i++) {
diff --git a/core/fs/pxe/pxe.h b/core/fs/pxe/pxe.h
index 279957ac..15252fff 100644
--- a/core/fs/pxe/pxe.h
+++ b/core/fs/pxe/pxe.h
@@ -231,6 +231,7 @@ int undiif_start(uint32_t ip, uint32_t netmask, uint32_t gw);
 void undiif_input(t_PXENV_UNDI_ISR *isr);
 
 /* dhcp_options.c */
+void parse_dhcp_options(const void *, int, uint8_t);
 void parse_dhcp(const void *, size_t);
 
 /* idle.c */
diff --git a/core/pxelinux.asm b/core/pxelinux.asm
index 953a906f..d4b1a07a 100644
--- a/core/pxelinux.asm
+++ b/core/pxelinux.asm
@@ -93,6 +93,7 @@ _start:
 hcdhcp_magic	dd 0x2983c8ac		; Magic number
 hcdhcp_len	dd 7*4			; Size of this structure
 hcdhcp_flags	dd 0			; Reserved for the future
+		global bdhcp_len, adhcp_len
 		; Parameters to be parsed before the ones from PXE
 bdhcp_offset	dd 0			; Offset (entered by patcher)
 bdhcp_len	dd 0			; Length (entered by patcher)