packets: Mask out CFI bit in eth_push_vlan().

[sliver-openvswitch.git] / lib / packets.c

diff --git a/lib/packets.c b/lib/packets.c
index b704276..2548174 100644 (file)
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -77,7 +77,7 @@ compose_benign_packet(struct ofpbuf *b, const char *tag, uint16_t snap_type,
 }
 
 /* Insert VLAN header according to given TCI. Packet passed must be Ethernet
- * packet.
+ * packet.  Ignores the CFI bit of 'tci' using 0 instead.
  *
  * Also sets 'packet->l2' to point to the new Ethernet header. */
 void
@@ -91,7 +91,7 @@ eth_push_vlan(struct ofpbuf *packet, ovs_be16 tci)
     memcpy(tmp.veth_dst, eh->eth_dst, ETH_ADDR_LEN);
     memcpy(tmp.veth_src, eh->eth_src, ETH_ADDR_LEN);
     tmp.veth_type = htons(ETH_TYPE_VLAN);
-    tmp.veth_tci = tci;
+    tmp.veth_tci = tci & htons(~VLAN_CFI);
     tmp.veth_next_type = eh->eth_type;
 
     veh = ofpbuf_push_uninit(packet, VLAN_HEADER_LEN);
@@ -100,6 +100,52 @@ eth_push_vlan(struct ofpbuf *packet, ovs_be16 tci)
     packet->l2 = packet->data;
 }
 
+/* Removes outermost VLAN header (if any is present) from 'packet'.
+ *
+ * 'packet->l2' must initially point to 'packet''s Ethernet header. */
+void
+eth_pop_vlan(struct ofpbuf *packet)
+{
+    struct vlan_eth_header *veh = packet->l2;
+    if (packet->size >= sizeof *veh
+        && veh->veth_type == htons(ETH_TYPE_VLAN)) {
+        struct eth_header tmp;
+
+        memcpy(tmp.eth_dst, veh->veth_dst, ETH_ADDR_LEN);
+        memcpy(tmp.eth_src, veh->veth_src, ETH_ADDR_LEN);
+        tmp.eth_type = veh->veth_next_type;
+
+        ofpbuf_pull(packet, VLAN_HEADER_LEN);
+        packet->l2 = (char*)packet->l2 + VLAN_HEADER_LEN;
+        memcpy(packet->data, &tmp, sizeof tmp);
+    }
+}
+
+/* Converts hex digits in 'hex' to an Ethernet packet in '*packetp'.  The
+ * caller must free '*packetp'.  On success, returns NULL.  On failure, returns
+ * an error message and stores NULL in '*packetp'. */
+const char *
+eth_from_hex(const char *hex, struct ofpbuf **packetp)
+{
+    struct ofpbuf *packet;
+
+    packet = *packetp = ofpbuf_new(strlen(hex) / 2);
+
+    if (ofpbuf_put_hex(packet, hex, NULL)[0] != '\0') {
+        ofpbuf_delete(packet);
+        *packetp = NULL;
+        return "Trailing garbage in packet data";
+    }
+
+    if (packet->size < ETH_HEADER_LEN) {
+        ofpbuf_delete(packet);
+        *packetp = NULL;
+        return "Packet data too short for Ethernet";
+    }
+
+    return NULL;
+}
+
 /* Given the IP netmask 'netmask', returns the number of bits of the IP address
  * that it specifies, that is, the number of 1-bits in 'netmask'.  'netmask'
  * must be a CIDR netmask (see ip_is_cidr()). */
@@ -259,7 +305,8 @@ ipv6_is_cidr(const struct in6_addr *netmask)
 /* Populates 'b' with an Ethernet II packet headed with the given 'eth_dst',
  * 'eth_src' and 'eth_type' parameters.  A payload of 'size' bytes is allocated
  * in 'b' and returned.  This payload may be populated with appropriate
- * information by the caller.
+ * information by the caller.  Sets 'b''s 'l2' and 'l3' pointers to the
+ * Ethernet header and payload respectively.
  *
  * The returned packet has enough headroom to insert an 802.1Q VLAN header if
  * desired. */
@@ -282,6 +329,9 @@ eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN],
     memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
     eth->eth_type = htons(eth_type);
 
+    b->l2 = eth;
+    b->l3 = data;
+
     return data;
 }