Add PPPOE-SERVER functionality

[l2tpns.git] / icmp.c

diff --git a/icmp.c b/icmp.c
index d115122..fa947b7 100644 (file)
--- a/icmp.c
+++ b/icmp.c
@@ -1,13 +1,12 @@
 // L2TPNS: icmp
 
-char const *cvs_id_icmp = "$Id: icmp.c,v 1.4 2004/11/15 02:26:20 bodea Exp $";
-
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <asm/types.h>
 #include <linux/ip.h>
 #include <linux/icmp.h>
+#include <netinet/icmp6.h>
 #include <stdio.h>
 #include <sys/socket.h>
 #include <unistd.h>
@@ -16,15 +15,23 @@ char const *cvs_id_icmp = "$Id: icmp.c,v 1.4 2004/11/15 02:26:20 bodea Exp $";
 #include <memory.h>
 
 #include "l2tpns.h"
+#include "pppoe.h"
+
+static uint16_t _checksum(uint8_t *addr, int count);
 
-__u16 _checksum(unsigned char *addr, int count);
+struct ipv6_pseudo_hdr {
+       struct in6_addr src;
+       struct in6_addr dest;
+       uint32_t ulp_length;
+       uint32_t zero    : 24;
+       uint32_t nexthdr :  8;
+};
 
-void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len)
+void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, uint8_t *packet, int packet_len)
 {
        char buf[128] = {0};
        struct iphdr *iph;
        struct icmphdr *icmp;
-       char *data;
        int len = 0, on = 1, icmp_socket;
        struct sockaddr_in whereto = {0};
 
@@ -40,9 +47,13 @@ void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int pac
        len = sizeof(struct iphdr);
        icmp = (struct icmphdr *)(buf + len);
        len += sizeof(struct icmphdr);
-       data = (char *)(buf + len);
-       len += (packet_len < 64) ? packet_len : 64;
-       memcpy(data, packet, (packet_len < 64) ? packet_len : 64);
+
+       /* ip header + first 8 bytes of payload */
+       if (packet_len > (sizeof(struct iphdr) + 8))
+               packet_len = sizeof(struct iphdr) + 8;
+
+       memcpy(buf + len, packet, packet_len);
+       len += packet_len;
 
        iph->tos = 0;
        iph->id = id;
@@ -60,21 +71,21 @@ void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int pac
 
        icmp->type = ICMP_DEST_UNREACH;
        icmp->code = ICMP_HOST_UNREACH;
-       icmp->checksum = _checksum((char *)icmp, sizeof(struct icmphdr) + ((packet_len < 64) ? packet_len : 64));
+       icmp->checksum = _checksum((uint8_t *) icmp, sizeof(struct icmphdr) + packet_len);
 
-       iph->check = _checksum((char *)iph, sizeof(struct iphdr));
+       iph->check = _checksum((uint8_t *) iph, sizeof(struct iphdr));
 
-       sendto(icmp_socket, (char *)buf, len, 0, (struct sockaddr *)&whereto, sizeof(struct sockaddr));
+       sendto(icmp_socket, buf, len, 0, (struct sockaddr *)&whereto, sizeof(struct sockaddr));
        close(icmp_socket);
 }
 
-__u16 _checksum(unsigned char *addr, int count)
+static uint16_t _checksum(uint8_t *addr, int count)
 {
        register long sum = 0;
 
        for (; count > 1; count -= 2)
        {
-               sum += ntohs(*(u32 *)addr);
+               sum += ntohs(*(uint32_t *) addr);
                addr += 2;
        }
 
@@ -87,5 +98,81 @@ __u16 _checksum(unsigned char *addr, int count)
        // one's complement the result
        sum = ~sum;
 
-       return htons((u16) sum);
+       return htons((uint16_t) sum);
+}
+
+void send_ipv6_ra(sessionidt s, tunnelidt t, struct in6_addr *ip)
+{
+       struct nd_opt_prefix_info *pinfo;
+       struct ipv6_pseudo_hdr *phdr;
+       uint8_t b[MAXETHER + 20];
+       uint8_t c[MAXETHER + 20];
+       int l;
+       uint8_t *o;
+
+       LOG(3, s, t, "Sending IPv6 RA\n");
+               
+       memset(b, 0, sizeof(b));
+       o = makeppp(b, sizeof(b), 0, 0, s, t, PPPIPV6, 0, 0, 0);
+
+       if (!o)
+       {
+               LOG(3, s, t, "failed to send IPv6 RA\n");
+               return;
+       }
+
+       *o = 0x60;                      // IPv6
+       *(o+1) = 0;
+       *(o+5) = 48;                    // Length of payload (not header)
+       *(o+6) = 58;                    // icmp6 is next
+       *(o+7) = 255;                   // Hop limit
+       memset(o+8, 0, 16);             // source = FE80::1
+       *(o+8) = 0xFE;
+       *(o+9) = 0x80;
+       *(o+23) = 1;
+       if (ip != NULL)
+       {
+               memcpy(o+24, ip, 16);   // dest = ip
+       }
+       else
+       {
+               // FF02::1 - all hosts
+               *(o+24) = 0xFF;
+               *(o+25) = 2;
+               *(o+39) = 1;
+       }
+       *(o+40) = 134;                  // RA message
+       *(o+41) = 0;                    // Code
+       *(o+42) = *(o+43) = 0;          // Checksum
+       *(o+44) = 64;                   // Hop count
+       *(o+45) = 0;                    // Flags
+       *(o+46) = *(o+47) = 255;        // Lifetime
+       *(uint32_t *)(o+48) = 0;        // Reachable time
+       *(uint32_t *)(o+52) = 0;        // Retrans timer
+       pinfo = (struct nd_opt_prefix_info *)(o+56);
+       pinfo->nd_opt_pi_type           = ND_OPT_PREFIX_INFORMATION;
+       pinfo->nd_opt_pi_len            = 4;
+       pinfo->nd_opt_pi_prefix_len     = 64; // prefix length
+       pinfo->nd_opt_pi_flags_reserved = ND_OPT_PI_FLAG_ONLINK;
+       pinfo->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
+       pinfo->nd_opt_pi_valid_time     = htonl(2592000);
+       pinfo->nd_opt_pi_preferred_time = htonl(604800);
+       pinfo->nd_opt_pi_reserved2      = 0;
+       pinfo->nd_opt_pi_prefix         = config->ipv6_prefix;
+       l = sizeof(*pinfo) + 56;
+
+       memset(c, 0, sizeof(c));
+       phdr = (struct ipv6_pseudo_hdr *) c;
+       memcpy(&phdr->src, o+8, 16);
+       memcpy(&phdr->dest, o+24, 16);
+       phdr->ulp_length = htonl(l - 40);
+       phdr->nexthdr = IPPROTO_ICMPV6;
+
+       memcpy(c + sizeof(*phdr), o + 40, l - 40);
+
+       // Checksum is over the icmp6 payload plus the pseudo header
+       *(uint16_t *)(o+42) = _checksum(c, l - 40 + sizeof(*phdr));
+
+       tunnelsend(b, l + (o-b), t); // send it...
+       return;
 }