Implement set-field for IPv6 ND fields (nd_target, nd_sll, and nd_tll).

[cascardo/ovs.git] / lib / packets.c

diff --git a/lib/packets.c b/lib/packets.c
index 65d8109..4d8aca9 100644 (file)
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -875,6 +875,58 @@ packet_set_sctp_port(struct ofpbuf *packet, ovs_be16 src, ovs_be16 dst)
     put_16aligned_be32(&sh->sctp_csum, old_csum ^ old_correct_csum ^ new_csum);
 }
 
+void
+packet_set_nd(struct ofpbuf *packet, const ovs_be32 target[4],
+              const uint8_t sll[ETH_ADDR_LEN],
+              const uint8_t tll[ETH_ADDR_LEN]) {
+    struct ovs_nd_msg *ns;
+    struct ovs_nd_opt *nd_opt;
+    int bytes_remain = ofpbuf_l4_size(packet);
+
+    if (OVS_UNLIKELY(bytes_remain < sizeof(*ns))) {
+        return;
+    }
+
+    ns = ofpbuf_l4(packet);
+    nd_opt = &ns->options[0];
+    bytes_remain -= sizeof(*ns);
+
+    if (memcmp(&ns->target, target, sizeof(ovs_be32[4]))) {
+        packet_set_ipv6_addr(packet, IPPROTO_ICMPV6,
+                             ns->target.be32,
+                             target, true);
+    }
+
+    while (bytes_remain >= ND_OPT_LEN && nd_opt->nd_opt_len != 0) {
+        if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LINKADDR
+            && nd_opt->nd_opt_len == 1) {
+            if (memcmp(nd_opt->nd_opt_data, sll, ETH_ADDR_LEN)) {
+                ovs_be16 *csum = &(ns->icmph.icmp6_cksum);
+
+                *csum = recalc_csum48(*csum, nd_opt->nd_opt_data, sll);
+                memcpy(nd_opt->nd_opt_data, sll, ETH_ADDR_LEN);
+            }
+
+            /* A packet can only contain one SLL or TLL option */
+            break;
+        } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LINKADDR
+                   && nd_opt->nd_opt_len == 1) {
+            if (memcmp(nd_opt->nd_opt_data, tll, ETH_ADDR_LEN)) {
+                ovs_be16 *csum = &(ns->icmph.icmp6_cksum);
+
+                *csum = recalc_csum48(*csum, nd_opt->nd_opt_data, tll);
+                memcpy(nd_opt->nd_opt_data, tll, ETH_ADDR_LEN);
+            }
+
+            /* A packet can only contain one SLL or TLL option */
+            break;
+        }
+
+        nd_opt += nd_opt->nd_opt_len;
+        bytes_remain -= nd_opt->nd_opt_len * ND_OPT_LEN;
+    }
+}
+
 const char *
 packet_tcp_flag_to_string(uint32_t flag)
 {
@@ -956,3 +1008,38 @@ packet_format_tcp_flags(struct ds *s, uint16_t tcp_flags)
         ds_put_cstr(s, "[800]");
     }
 }
+
+#define ARP_PACKET_SIZE  (2 + ETH_HEADER_LEN + VLAN_HEADER_LEN + \
+                          ARP_ETH_HEADER_LEN)
+
+void
+compose_arp(struct ofpbuf *b, const uint8_t eth_src[ETH_ADDR_LEN],
+            ovs_be32 ip_src, ovs_be32 ip_dst)
+{
+    struct eth_header *eth;
+    struct arp_eth_header *arp;
+
+    ofpbuf_clear(b);
+    ofpbuf_prealloc_tailroom(b, ARP_PACKET_SIZE);
+    ofpbuf_reserve(b, 2 + VLAN_HEADER_LEN);
+
+    eth = ofpbuf_put_uninit(b, sizeof *eth);
+    memcpy(eth->eth_dst, eth_addr_broadcast, ETH_ADDR_LEN);
+    memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
+    eth->eth_type = htons(ETH_TYPE_ARP);
+
+    arp = ofpbuf_put_uninit(b, sizeof *arp);
+    arp->ar_hrd = htons(ARP_HRD_ETHERNET);
+    arp->ar_pro = htons(ARP_PRO_IP);
+    arp->ar_hln = sizeof arp->ar_sha;
+    arp->ar_pln = sizeof arp->ar_spa;
+    arp->ar_op = htons(ARP_OP_REQUEST);
+    memcpy(arp->ar_sha, eth_src, ETH_ADDR_LEN);
+    memset(arp->ar_tha, 0, ETH_ADDR_LEN);
+
+    put_16aligned_be32(&arp->ar_spa, ip_src);
+    put_16aligned_be32(&arp->ar_tpa, ip_dst);
+
+    ofpbuf_set_frame(b, eth);
+    ofpbuf_set_l3(b, arp);
+}