X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/c239d4b22829335fda98b66ce045a3f624436eeb..14db37d6230b67fcb2897729a626ad35dbe41d06:/icmp.c

diff --git a/icmp.c b/icmp.c
index f7d73c6..5f05127 100644
--- a/icmp.c
+++ b/icmp.c
@@ -1,31 +1,44 @@
+// L2TPNS: icmp
+
 #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>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <memory.h>
+#include <linux/rtnetlink.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};
 
-	if (!(icmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)))
+	if ((icmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
 		return;
+
 	setsockopt(icmp_socket, IPPROTO_IP, IP_HDRINCL, (char *)&on, sizeof(on));
 
 	whereto.sin_addr.s_addr = destination;
@@ -35,9 +48,13 @@ 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;
@@ -55,21 +72,21 @@ 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;
 	}
 
@@ -82,5 +99,81 @@ __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;
 }