X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/97ad99cc23c5f0007de461afb200fd83c3d20481..935445b29ab2952f928f347e0446bc81ab5f6229:/icmp.c diff --git a/icmp.c b/icmp.c index e0913ab..0d6c65e 100644 --- a/icmp.c +++ b/icmp.c @@ -1,39 +1,23 @@ // L2TPNS: icmp -char const *cvs_id_icmp = "$Id: icmp.c,v 1.7 2005/01/25 04:19:05 bodea Exp $"; - #include -#include -#include -#include #include #include #include -#include -#include #include -#include -#include -#include +#include +#include "dhcp6.h" #include "l2tpns.h" +#include "ipv6_u.h" -static uint16_t _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; -}; +static uint16_t _checksum(uint8_t *addr, int count); -void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t 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}; @@ -49,9 +33,13 @@ void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, char 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; @@ -69,25 +57,25 @@ void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, char 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); } -static uint16_t _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(*(uint32_t *) addr); + sum += ntohs(*(uint16_t *) addr); addr += 2; } - if (count > 1) sum += *(unsigned char *)addr; + if (count > 0) sum += *(unsigned char *)addr; // take only 16 bits out of the 32 bit sum and add up the carries while (sum >> 16) @@ -99,76 +87,78 @@ static uint16_t _checksum(unsigned char *addr, int count) return htons((uint16_t) sum); } -void send_ipv6_ra(tunnelidt t, sessionidt s, struct in6_addr *ip) +void send_ipv6_ra(sessionidt s, tunnelidt t, struct in6_addr *ip) { struct nd_opt_prefix_info *pinfo; - struct ipv6_pseudo_hdr *phdr; + struct ip6_hdr *p_ip6_hdr; + struct nd_router_advert *p_nra; uint8_t b[MAXETHER + 20]; - uint8_t c[MAXETHER + 20]; + struct ipv6_pseudo_hdr pseudo_hdr; 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, t, s, PPPIPV6); + p_ip6_hdr = (struct ip6_hdr *) makeppp(b, sizeof(b), 0, 0, s, t, PPPIPV6, 0, 0, 0); - if (!o) + if (!p_ip6_hdr) { 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; + p_ip6_hdr->ip6_vfc = 0x60; // IPv6 + p_ip6_hdr->ip6_plen = 0; // Length of payload (not header) (calculation below) + p_ip6_hdr->ip6_nxt = IPPROTO_ICMPV6; // icmp6 is next + p_ip6_hdr->ip6_hlim = 255; // Hop limit + // IPv6 0xFE80::1 + inet_pton(AF_INET6, "FE80::1", &p_ip6_hdr->ip6_src.s6_addr); + if (ip != NULL) - memcpy(o+24, ip, 16); // dest = ip + { + memcpy(p_ip6_hdr->ip6_dst.s6_addr, ip, 16); // dest = ip + } else { // FF02::1 - all hosts - *(o+24) = 0xFF; - *(o+25) = 2; - *(o+39) = 1; + inet_pton(AF_INET6, "FF02::1", &p_ip6_hdr->ip6_dst.s6_addr); } - *(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); + + // RA message after Ipv6 header + p_nra = (struct nd_router_advert *) &p_ip6_hdr[1]; + p_nra->nd_ra_type = ND_ROUTER_ADVERT; // RA message (134) + p_nra->nd_ra_code = 0; // Code + p_nra->nd_ra_cksum = 0; // Checksum + p_nra->nd_ra_curhoplimit = 64; // Hop count + p_nra->nd_ra_flags_reserved = (ND_RA_FLAG_MANAGED|ND_RA_FLAG_OTHER); // Flags + p_nra->nd_ra_router_lifetime = 0xFFFF; // Lifetime + p_nra->nd_ra_reachable = 0; // Reachable time + p_nra->nd_ra_retransmit = 0; // Retrans timer + // Option PI after RA message (rfc4861) + pinfo = (struct nd_opt_prefix_info *) &p_nra[1]; 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_flags_reserved = ND_OPT_PI_FLAG_ONLINK | 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_len = 64; // prefix length 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; + // // Length of payload (not header) + p_ip6_hdr->ip6_plen = htons(sizeof(*pinfo) + sizeof(*p_nra)); - memcpy(c + sizeof(*phdr), o + 40, l - 40); + l = sizeof(*pinfo) + sizeof(*p_nra) + sizeof(*p_ip6_hdr); + /* Use pseudo hearder for checksum calculation */ + memset(&pseudo_hdr, 0, sizeof(pseudo_hdr)); + memcpy(&pseudo_hdr.src, &p_ip6_hdr->ip6_src, 16); + memcpy(&pseudo_hdr.dest, &p_ip6_hdr->ip6_dst, 16); + pseudo_hdr.ulp_length = htonl(sizeof(*pinfo) + sizeof(*p_nra)); // Lenght whitout Ipv6 header + pseudo_hdr.nexthdr = IPPROTO_ICMPV6; // Checksum is over the icmp6 payload plus the pseudo header - *(uint16_t *)(o+42) = _checksum(c, l - 40 + sizeof(*phdr)); + p_nra->nd_ra_cksum = ipv6_checksum(&pseudo_hdr, (uint8_t *) p_nra, (sizeof(*pinfo) + sizeof(*p_nra))); - tunnelsend(b, l + (o-b), t); // send it... + tunnelsend(b, l + (((uint8_t *) p_ip6_hdr)-b), t); // send it... return; }