fix the ipv6 checksum calculation for pseudoheader so that it actually works

add support to send ipv6 "gratious arp" aka neighbor solicitation packets from ctdb

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>

diff --git a/common/system_linux.c b/common/system_linux.c
index 760877fe3ad65e3c4e9f2ada6b9f895a155cfc3f..c7e66eb9761116edb1f6e9b1581bed0cbe3168b7 100644 (file)
--- a/common/system_linux.c
+++ b/common/system_linux.c
@@ -26,9 +26,58 @@
 #include "lib/events/events.h"
 #include <netinet/if_ether.h>
 #include <netinet/ip6.h>
+#include <netinet/icmp6.h>
 #include <net/if_arp.h>
 
 
+#ifndef ETHERTYPE_IP6
+#define ETHERTYPE_IP6 0x86dd
+#endif
+
+/*
+  uint16 checksum for n bytes
+ */
+static uint32_t uint16_checksum(uint16_t *data, size_t n)
+{
+       uint32_t sum=0;
+       while (n>=2) {
+               sum += (uint32_t)ntohs(*data);
+               data++;
+               n -= 2;
+       }
+       if (n == 1) {
+               sum += (uint32_t)ntohs(*(uint8_t *)data);
+       }
+       return sum;
+}
+
+/*
+  calculate the tcp checksum for tcp over ipv6
+*/
+static uint16_t tcp_checksum6(uint16_t *data, size_t n, struct ip6_hdr *ip6)
+{
+       uint32_t phdr[2];
+       uint32_t sum = 0;
+       uint16_t sum2;
+
+       sum += uint16_checksum((uint16_t *)(void *)&ip6->ip6_src, 16);
+       sum += uint16_checksum((uint16_t *)(void *)&ip6->ip6_dst, 16);
+
+       phdr[0] = htonl(n);
+       phdr[1] = htonl(ip6->ip6_nxt);
+       sum += uint16_checksum((uint16_t *)phdr, 8);
+
+       sum += uint16_checksum(data, n);
+
+       sum = (sum & 0xFFFF) + (sum >> 16);
+       sum = (sum & 0xFFFF) + (sum >> 16);
+       sum2 = htons(sum);
+       sum2 = ~sum2;
+       if (sum2 == 0) {
+               return 0xFFFF;
+       }
+       return sum2;
+}
 
 /*
   send gratuitous arp reply after we have taken over an ip address
@@ -42,8 +91,10 @@ int ctdb_sys_send_arp(const ctdb_sock_addr *addr, const char *iface)
        struct sockaddr sa;
        struct ether_header *eh;
        struct arphdr *ah;
+       struct ip6_hdr *ip6;
+       struct icmp6_hdr *icmp6;
        struct ifreq if_hwaddr;
-       unsigned char buffer[64]; /*minimum eth frame size */
+       unsigned char buffer[78]; /* ipv6 neigh solicitation size */
        char *ptr;
 
        ZERO_STRUCT(sa);
@@ -129,10 +180,68 @@ int ctdb_sys_send_arp(const ctdb_sock_addr *addr, const char *iface)
                        return -1;
                }
 
+               close(s);
+               break;
+       case AF_INET6:
+               s = socket(AF_INET, SOCK_PACKET, htons(ETHERTYPE_IP6));
+               if (s == -1){
+                       DEBUG(DEBUG_CRIT,(__location__ " failed to open raw socket\n"));
+                       return -1;
+               }
+
+               /* get the mac address */
+               strcpy(if_hwaddr.ifr_name, iface);
+               ret = ioctl(s, SIOCGIFHWADDR, &if_hwaddr);
+               if ( ret < 0 ) {
+                       close(s);
+                       DEBUG(DEBUG_CRIT,(__location__ " ioctl failed\n"));
+                       return -1;
+               }
+               if (ARPHRD_LOOPBACK == if_hwaddr.ifr_hwaddr.sa_family) {
+                       DEBUG(DEBUG_DEBUG,("Ignoring loopback arp request\n"));
+                       close(s);
+                       return 0;
+               }
+               if (if_hwaddr.ifr_hwaddr.sa_family != AF_LOCAL) {
+                       close(s);
+                       errno = EINVAL;
+                       DEBUG(DEBUG_CRIT,(__location__ " not an ethernet address family (0x%x)\n",
+                                if_hwaddr.ifr_hwaddr.sa_family));
+                       return -1;
+               }
+
+               memset(buffer, 0 , sizeof(buffer));
+               eh = (struct ether_header *)buffer;
+               memset(eh->ether_dhost, 0xff, ETH_ALEN);
+               memcpy(eh->ether_shost, if_hwaddr.ifr_hwaddr.sa_data, ETH_ALEN);
+               eh->ether_type = htons(ETHERTYPE_IP6);
+
+               ip6 = (struct ip6_hdr *)(eh+1);
+               ip6->ip6_vfc  = 0x60;
+               ip6->ip6_plen = htons(24);
+               ip6->ip6_nxt  = IPPROTO_ICMPV6;
+               ip6->ip6_hlim = 255;
+               ip6->ip6_dst  = addr->ip6.sin6_addr;
+
+               icmp6 = (struct icmp6_hdr *)(ip6+1);
+               icmp6->icmp6_type = ND_NEIGHBOR_SOLICIT;
+               icmp6->icmp6_code = 0;
+               memcpy(&icmp6->icmp6_data32[1], &addr->ip6.sin6_addr, 16);
+
+               icmp6->icmp6_cksum = tcp_checksum6((uint16_t *)icmp6, ntohs(ip6->ip6_plen), ip6);
+
+               strncpy(sa.sa_data, iface, sizeof(sa.sa_data));
+               ret = sendto(s, buffer, 78, 0, &sa, sizeof(sa));
+               if (ret < 0 ){
+                       close(s);
+                       DEBUG(DEBUG_CRIT,(__location__ " failed sendto\n"));
+                       return -1;
+               }       
+
                close(s);
                break;
        default:
-               DEBUG(DEBUG_CRIT,(__location__ " not an ipv4 address (family is %u)\n", addr->ip.sin_family));
+               DEBUG(DEBUG_CRIT,(__location__ " not an ipv4/ipv6 address (family is %u)\n", addr->ip.sin_family));
                return -1;
        }
 
@@ -140,23 +249,6 @@ int ctdb_sys_send_arp(const ctdb_sock_addr *addr, const char *iface)
 }
 
 
-/*
-  uint16 checksum for n bytes
- */
-static uint32_t uint16_checksum(uint16_t *data, size_t n)
-{
-       uint32_t sum=0;
-       while (n>=2) {
-               sum += (uint32_t)ntohs(*data);
-               data++;
-               n -= 2;
-       }
-       if (n == 1) {
-               sum += (uint32_t)ntohs(*(uint8_t *)data);
-       }
-       return sum;
-}
-
 /*
   simple TCP checksum - assumes data is multiple of 2 bytes long
  */
@@ -179,29 +271,6 @@ static uint16_t tcp_checksum(uint16_t *data, size_t n, struct iphdr *ip)
        return sum2;
 }
 
-/*
-  calculate the tcp checksum for tcp over ipv6
-*/
-static uint16_t tcp_checksum6(uint16_t *data, size_t n, struct ip6_hdr *ip6)
-{
-       uint32_t sum = uint16_checksum(data, n);
-       uint16_t sum2;
-
-       sum += uint16_checksum((uint16_t *)(void *)&ip6->ip6_src, 16);
-       sum += uint16_checksum((uint16_t *)(void *)&ip6->ip6_dst, 16);
-       sum += ip6->ip6_plen;
-       sum += ip6->ip6_nxt;
-                       
-       sum = (sum & 0xFFFF) + (sum >> 16);
-       sum = (sum & 0xFFFF) + (sum >> 16);
-       sum2 = htons(sum);
-       sum2 = ~sum2;
-       if (sum2 == 0) {
-               return 0xFFFF;
-       }
-       return sum2;
-}
-
 /*
   Send tcp segment from the specified IP/port to the specified
   destination IP/port. 
@@ -285,7 +354,7 @@ int ctdb_sys_send_tcp(const ctdb_sock_addr *dest,
        case AF_INET6:
                ZERO_STRUCT(ip6pkt);
                ip6pkt.ip6.ip6_vfc  = 0x60;
-               ip6pkt.ip6.ip6_plen = 20;
+               ip6pkt.ip6.ip6_plen = htons(20);
                ip6pkt.ip6.ip6_nxt  = IPPROTO_TCP;
                ip6pkt.ip6.ip6_hlim = 64;
                ip6pkt.ip6.ip6_src  = src->ip6.sin6_addr;
@@ -451,9 +520,6 @@ int ctdb_sys_read_tcp_packet(int s, void *private_data,
                *seq                    = tcp->seq;
 
                return 0;
-#ifndef ETHERTYPE_IP6
-#define ETHERTYPE_IP6 0x86dd
-#endif
        } else if (ntohs(eth->ether_type) == ETHERTYPE_IP6) {
                /* IP6 */
                ip6 = (struct ip6_hdr *)(eth+1);

diff --git a/tests/nodes.txt b/tests/nodes.txt
index 2563adcc702f968c53a96106e7209090d7b85a3e..20e29b14832946c6aac260c6a1c1492e2500c0c0 100644 (file)
--- a/tests/nodes.txt
+++ b/tests/nodes.txt
@@ -1,4 +1 @@
 ::1
-::2
-::3
-::4