net: Enhancements for dhcp option 209
- Enable option 209 by default
- Set pxelinux_configfile to NULL to avoid potential double free
- change hardcoded 209 to a define
Signed-off-by: Sean Edmond <seanedmond@microsoft.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index c182d73..54c4ab8 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1898,6 +1898,7 @@
config BOOTP_PXE_DHCP_OPTION
bool "Request & store 'pxe_configfile' from BOOTP/DHCP server"
+ default y
depends on BOOTP_PXE
config BOOTP_VCI_STRING
diff --git a/cmd/pxe.c b/cmd/pxe.c
index 21134eb..9404f44 100644
--- a/cmd/pxe.c
+++ b/cmd/pxe.c
@@ -65,6 +65,8 @@
int ret = get_pxe_file(ctx, pxelinux_configfile, pxefile_addr_r);
free(pxelinux_configfile);
+ /* set to NULL to avoid double-free if DHCP is tried again */
+ pxelinux_configfile = NULL;
return ret;
}
diff --git a/net/bootp.c b/net/bootp.c
index c15472f..b9e3ccc 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -603,7 +603,7 @@
*cnt += 1;
#endif
if (IS_ENABLED(CONFIG_BOOTP_PXE_DHCP_OPTION)) {
- *e++ = 209; /* PXELINUX Config File */
+ *e++ = DHCP_OPTION_PXE_CONFIG_FILE; /* PXELINUX Config File */
*cnt += 1;
}
/* no options, so back up to avoid sending an empty request list */
@@ -922,7 +922,7 @@
net_boot_file_name[size] = 0;
}
break;
- case 209: /* PXELINUX Config File */
+ case DHCP_OPTION_PXE_CONFIG_FILE: /* PXELINUX Config File */
if (IS_ENABLED(CONFIG_BOOTP_PXE_DHCP_OPTION)) {
/* In case it has already been allocated when get DHCP Offer packet,
* free first to avoid memory leak.
diff --git a/net/bootp.h b/net/bootp.h
index 4e32b19..24b32c7 100644
--- a/net/bootp.h
+++ b/net/bootp.h
@@ -91,6 +91,8 @@
#define DHCP_NAK 6
#define DHCP_RELEASE 7
+#define DHCP_OPTION_PXE_CONFIG_FILE 209 /* "ConfigFile" option according to rfc5071 */
+
/**********************************************************************/
#endif /* __BOOTP_H__ */