Workaround for UEFI PXE boot problems.

src/rfc2131.c

@@ -63,7 +63,7 @@ static void pxe_misc(struct dhcp_packet *mess, unsigned char *end, unsigned char
 static int prune_vendor_opts(struct dhcp_netid *netid);
 static struct dhcp_opt *pxe_opts(int pxe_arch, struct dhcp_netid *netid, struct in_addr local, time_t now);
 struct dhcp_boot *find_boot(struct dhcp_netid *netid);
-
+static int pxe_uefi_workaround(int pxe_arch, struct dhcp_netid *netid, struct dhcp_packet *mess, struct in_addr local, time_t now);
   
 size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		  size_t sz, time_t now, int unicast_dest, int *is_inform, int pxe, struct in_addr fallback)
@@ -851,6 +851,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	  if ((mess_type == DHCPDISCOVER || (pxe && mess_type == DHCPREQUEST)))
 	    {
 	      struct dhcp_context *tmp;
+	      int workaround = 0;
 	      
 	      for (tmp = context; tmp; tmp = tmp->current)
 		if ((tmp->flags & CONTEXT_PROXY) &&
@@ -878,10 +879,16 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		  
 		  clear_packet(mess, end);
 		  
-		  /* Provide the bootfile here, for gPXE, and in case we have no menu items
-		     and set discovery_control = 8 */
-		  if (boot)
+		  /* Only do workaround for replies to 4011 */
+		  if (!pxe)
+		    mess->siaddr = tmp->local;
+		  else 
+		    workaround = pxe_uefi_workaround(pxearch, tagif_netid, mess, tmp->local, now);
+		  
+		  if (!workaround && boot)
 		    {
+		      /* Provide the bootfile here, for gPXE, and in case we have no menu items
+			 and set discovery_control = 8 */
 		      if (boot->next_server.s_addr) 
 			mess->siaddr = boot->next_server;
 		      else if (boot->tftp_sname) 
@@ -896,8 +903,9 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		  option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, htonl(tmp->local.s_addr));
 		  pxe_misc(mess, end, uuid);
 		  prune_vendor_opts(tagif_netid);
-		  do_encap_opts(pxe_opts(pxearch, tagif_netid, tmp->local, now), OPTION_VENDOR_CLASS_OPT, DHOPT_VENDOR_MATCH, mess, end, 0);
-		  
+		  if (!workaround)
+		    do_encap_opts(pxe_opts(pxearch, tagif_netid, tmp->local, now), OPTION_VENDOR_CLASS_OPT, DHOPT_VENDOR_MATCH, mess, end, 0);
+	    
 		  log_packet("PXE", NULL, emac, emac_len, iface_name, ignore ? "proxy-ignored" : "proxy", NULL, mess->xid);
 		  log_tags(tagif_netid, ntohl(mess->xid));
 		  return ignore ? 0 : dhcp_packet_size(mess, agent_id, real_end);	  
@@ -1975,6 +1983,52 @@ static int prune_vendor_opts(struct dhcp_netid *netid)
   return force;
 }
 
+
+/* Many UEFI PXE implementations have badly broken menu code.
+   If there's exactly one relevant menu item, we abandon the menu system,
+   and jamb the data direct into the DHCP file, siaddr and sname fields.
+   Note that in this case, we have to assume that layer zero would be requested
+   by the client PXE stack. */
+static int pxe_uefi_workaround(int pxe_arch, struct dhcp_netid *netid, struct dhcp_packet *mess, struct in_addr local, time_t now)
+{
+  struct pxe_service *service, *found;
+
+  /* Only workaround UEFI archs. */
+  if (pxe_arch != 6 && pxe_arch != 7 && pxe_arch != 8 && pxe_arch != 9)
+    return 0;
+  
+  for (found = NULL, service = daemon->pxe_services; service; service = service->next)
+    if (pxe_arch == service->CSA && match_netid(service->netid, netid, 1))
+      {
+	if (found)
+	  return 0; /* More than one relevant menu item */
+	  
+	found = service;
+      }
+
+  if (!found)
+    return 0; /* No relevant menu items. */
+  
+  if (found->sname)
+    {
+      mess->siaddr = a_record_from_hosts(found->sname, now);
+      snprintf((char *)mess->sname, sizeof(mess->sname), "%s", found->sname);
+    }
+  else 
+    {
+      if (found->server.s_addr != 0)
+	mess->siaddr = found->server; 
+      else
+	mess->siaddr = local;
+  
+      inet_ntop(AF_INET, &mess->siaddr, (char *)mess->sname, INET_ADDRSTRLEN);
+    }
+  
+  snprintf((char *)mess->file, sizeof(mess->file), "%s.0", found->basename);
+
+  return 1;
+}
+
 static struct dhcp_opt *pxe_opts(int pxe_arch, struct dhcp_netid *netid, struct in_addr local, time_t now)
 {
 #define NUM_OPTS 4  
@@ -2509,7 +2563,8 @@ static void do_options(struct dhcp_context *context,
   if (context && pxe_arch != -1)
     {
       pxe_misc(mess, end, uuid);
-      config_opts = pxe_opts(pxe_arch, tagif, context->local, now);
+      if (!pxe_uefi_workaround(pxe_arch, tagif, mess, context->local, now))
+	config_opts = pxe_opts(pxe_arch, tagif, context->local, now);
     }
 
   if ((force_encap || in_list(req_options, OPTION_VENDOR_CLASS_OPT)) &&