We shouldn't stamp on the dhcp message when checking overloads.

diff --git a/dhcp.c b/dhcp.c
index 3e89430367efab562639ff96f9a90d121ee47b66..ec2359f93390db0b142a02e0ea35c36c977dd25a 100644 (file)
--- a/dhcp.c
+++ b/dhcp.c
@@ -241,6 +241,7 @@ _get_option(const struct dhcp_message *dhcp, uint8_t opt, int *type)
        const uint8_t *e = p + sizeof(dhcp->options);
        uint8_t l;
        uint8_t o = 0;
+       uint8_t overl = 0;
 
        while (p < e) {
                o = *p++;
@@ -254,26 +255,22 @@ _get_option(const struct dhcp_message *dhcp, uint8_t opt, int *type)
                case DHCP_PAD:
                        continue;
                case DHCP_END:
-                       if (o) {
-                               if (o & 1) {
-                                       /* bit 1 set means parse boot file */
-                                       o &= ~1;
-                                       p = dhcp->bootfile;
-                                       e = p + sizeof(dhcp->bootfile);
-                               } else if (o & 2) {
-                                       /* bit 2 set means parse server name */
-                                       o &= ~2;
-                                       p = dhcp->servername;
-                                       e = p + sizeof(dhcp->servername);
-                               }
+                       if (overl & 1) {
+                               /* bit 1 set means parse boot file */
+                               overl &= ~1;
+                               p = dhcp->bootfile;
+                               e = p + sizeof(dhcp->bootfile);
+                       } else if (overl & 2) {
+                               /* bit 2 set means parse server name */
+                               overl &= ~2;
+                               p = dhcp->servername;
+                               e = p + sizeof(dhcp->servername);
                        }
                        break;
                case DHCP_OPTIONSOVERLOADED:
                        /* Ensure we only get this option once */
-                       if (!(o & 4)) {
-                               o = p[1];
-                               o |= 4;
-                       }
+                       if (! overl)
+                               overl = p[1];
                        break;
                }