X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/b43583c01d146d8cc3cb826937efe3d0f47ec819..3d9333a6cbe22f3961849e595ae801cccc4a72fb:/icmp.c?ds=inline diff --git a/icmp.c b/icmp.c index 0a56740..41f165b 100644 --- a/icmp.c +++ b/icmp.c @@ -1,31 +1,44 @@ +// L2TPNS: icmp + +char const *cvs_id_icmp = "$Id: icmp.c,v 1.11 2006/04/27 09:53:49 bodea Exp $"; + #include #include #include +#include #include #include +#include #include #include #include #include #include #include + #include "l2tpns.h" -extern ipt myip; +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 +99,79 @@ __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; }