From: Ethan Jackson <ethan@nicira.com>
Date: Wed, 23 Mar 2011 19:59:40 +0000 (-0700)
Subject: packets: Create new compose_packet() function.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=40f78b38e745019e08b3cfe06ddf205f0cc4b970;p=openvswitch

packets: Create new compose_packet() function.

This commit generalizes compose_lacp_packet() into new
compose_packet() function.  This new function will be used to send
CCM messages in future patches.
---

diff --git a/lib/packets.c b/lib/packets.c
index 60ee3903..6ee7aa83 100644
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -204,24 +204,29 @@ ipv6_is_cidr(const struct in6_addr *netmask)
     return true;
 }
 
-/* Populates 'b' with a LACP packet containing 'pdu' with source address
- * 'eth_src'. */
-void
-compose_lacp_packet(struct ofpbuf *b, const uint8_t eth_src[ETH_ADDR_LEN],
-                    const struct lacp_pdu *pdu)
+/* Populates 'b' with an L2 packet headed with the given 'eth_dst', 'eth_src'
+ * and 'eth_type' paramaters.  A payload of 'size' bytes is allocated in 'b'
+ * and returned.  This payload may be populated with appropriate information by
+ * the caller. */
+void *
+compose_packet(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN],
+               const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
+               size_t size)
 {
+    void *data;
     struct eth_header *eth;
-    struct lacp_pdu *eth_pdu;
 
     ofpbuf_clear(b);
 
-    ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + LACP_PDU_LEN);
-    eth = ofpbuf_put_zeros(b, ETH_HEADER_LEN);
-    eth_pdu = ofpbuf_put(b, pdu, LACP_PDU_LEN);
+    ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + size);
+    eth = ofpbuf_put_uninit(b, ETH_HEADER_LEN);
+    data = ofpbuf_put_uninit(b, size);
 
-    memcpy(eth->eth_dst, eth_addr_lacp, ETH_ADDR_LEN);
+    memcpy(eth->eth_dst, eth_dst, ETH_ADDR_LEN);
     memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
-    eth->eth_type = htons(ETH_TYPE_LACP);
+    eth->eth_type = htons(eth_type);
+
+    return data;
 }
 
 /* Populates 'pdu' with a LACP PDU comprised of 'actor' and 'partner'. */
diff --git a/lib/packets.h b/lib/packets.h
index c858fc09..bf071e8e 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -412,6 +412,11 @@ struct in6_addr ipv6_create_mask(int mask);
 int ipv6_count_cidr_bits(const struct in6_addr *netmask);
 bool ipv6_is_cidr(const struct in6_addr *netmask);
 
+void *
+compose_packet(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
+               const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
+               size_t size);
+
 /* Masks for lacp_info state member. */
 #define LACP_STATE_ACT  0x01 /* Activity. Active or passive? */
 #define LACP_STATE_TIME 0x02 /* Timeout. Short or long timeout? */
@@ -460,9 +465,6 @@ struct lacp_pdu {
 } __attribute__((packed));
 BUILD_ASSERT_DECL(LACP_PDU_LEN == sizeof(struct lacp_pdu));
 
-void compose_lacp_packet(struct ofpbuf *, const uint8_t eth_src[ETH_ADDR_LEN],
-                         const struct lacp_pdu *);
-
 void compose_lacp_pdu(const struct lacp_info *actor,
                       const struct lacp_info *partner, struct lacp_pdu *);
 
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index bcaf1d12..455bc58b 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -3811,9 +3811,12 @@ lacp_send_pdu_cb(void *aux, const struct lacp_pdu *pdu)
     error = netdev_get_etheraddr(iface->netdev, ea);
     if (!error) {
         struct ofpbuf packet;
+        struct lacp_pdu *packet_pdu;
 
-        ofpbuf_init(&packet, ETH_HEADER_LEN + LACP_PDU_LEN);
-        compose_lacp_packet(&packet, ea, pdu);
+        ofpbuf_init(&packet, 0);
+        packet_pdu = compose_packet(&packet, eth_addr_lacp, ea, ETH_TYPE_LACP,
+                                    sizeof *packet_pdu);
+        memcpy(packet_pdu, pdu, sizeof *packet_pdu);
         ofproto_send_packet(iface->port->bridge->ofproto,
                             iface->dp_ifidx, 0, &packet);
         ofpbuf_uninit(&packet);